* GB784993 (A)

Description: GB784993 (A) ? 1957-10-23

Improvements in or relating to the construction of electronic equipment

Description of GB784993 (A)

PATENT SPECIFICATION Inventor: DAVID LIONEL SWALE Date of filing Complete Specification: Aug 22, 1955. Application Date: Aug 25, 1954. No 24796/54. ?/ Complete Specification Published: Oct 23, 1957. Index at acceptance:-Class 37, TI. International Classification:-H Olbo COMPLETE SPECIFICATION Improvements in or relating to the Construction of Electronic Equipment We, THE DECCA RECORD COMPANY LIMITED, a British Company, of 1-3, Brixton Road, London, S W 9, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to the construction of eectronic equipment. It is well known to construct complex electronic equipment in the form of a number of units which can be separaretly removed and replaced, A unit construction provides considerable advantages, notably in ease of servicing which is facilitated both by enabling substitution of a faulty unit to be rapidly effected and by the ease of handling and accessibility for repair of a unit Furthermore, the use of standard sized units greatly facilitates the 'design and construction of complex equipment since the required combination of units can be assembled into a standard framework or cabinet, with the possibility of the combination incorporating, in many cases, existing or standard units. Unit construction is particularly advantageous for complex radar display systems since many units can be made identical for various different types of display and thus it becomes a simple matter to provide various types of displays according to requirements making use

of standard units. The present invention is directed more particularly to the construction of such units and, according to the invention, a unit for use in electronic equipment comprises a U-shaped channel with outwardly-directed flanges cn the side walls of the U, valve holders being mounted on the base of the U so that valves in the holders lie between the side walls of the U-shaped channel Preferably all or at least a majority:of the resistors, condensers and, like components are mounted between the flanges and the outer faces of the side walls of the U This construction permits of easy access to the components thereby facilitating lPrice 3 s 6 d l servicing of the equipment. The side walls are preferably formed as continuous walls of uniform height, the height being sufficient that none of the valves when mounted in the valve holders, protrude above the top of the walls Preferably the flanges are at the outer edges of the side walls of the 'U and the resistors and other components arranged between the flange and the side walls of the U at an angle to the plane of the latter, Positioning the components in this manner is a further feature facilitating ease of servicing. The form of unit described above, when installed in a mounting can be arranged to provide an air duct for cooling the valves, since the latter are situated in the channel of the U Conveniently the units are assembled in the mounting with the U-shaped channels inverted By providing a solid base for supporting the unit, the channel of the U is formed into a closed duct and the units are preferably positioned so that air can be forced through the channels from one end thereof for cooling the valves For example, the units may be positioned with one end of the channel adjacent a face plate on the mounting having an aperture which communicates with the interior of the channel By such a construction the cooling air may be forced over the valves whilst avoiding any air stream on the resistors and other components on the outer side of each unit This is often advantageous in avoiding or reducing instability due to variations in component values. Each unit may be made so that it can be lowered directly onto its mounting and then secured in position by one or more bolts and, in this construction, a plug and socket assembly may be provided for making electrical connections to the unit, one part of the plug and socket assembly being fixed to the unit and the other part to the mounting in such manner that the plug engages the socket on dowmvnward movement of the unit onto the base plate of the mounting In an alternative 784,993 construction, the unit can be lowered into its mounting and then moved in the axial direction of the channel so as to bring into engagement, by the axial movement, a plug and socket for electrically connecting the unit to wiring in the mounting Screw means

may be provided for effecting an axial movement of the unit Such screw means may be sufficient to secure -the unit in position but if desired a clamp or clamps may be provided. The screw means may comprise a screw with a knurled knob at one end, the screw engaging a fixed threaded bush on the mounting The end of the screw remote from the knob may be provided with a cylindrical head having a circumferential channel in the cylindrical surface, which channel engages a fork or the like on the unit, the fork straddling the screw. The axial movement of the unit may conveniently be arranged not only to engage the plug and socket but also to bring the channel into engagement with the air supply duct by forcing one end of the unit tightly against a plate on the mounting having an aperture as described above. The plug and socket are preferably provided with a locating peg to ensure that the pins are correctly engaged Preferably also the unit and mounting have mutually engaging male and female elements to ensure correct locating during the axial movement. Although the unit described above is particularly suitable for forced draught ventilation as described above, it may also be used in an assembly in which the channel is stood on end to provide convection current cooling, the unit being fitted in a suitably louvred container to permit adequate air flow. If the unit as described above, having flanges at the outer edges of the side walls, is arranged for use with the channel inverted, it is convenient to provide two or more handles bridging over the top of the unit, i.e over the base of the U (considering the channel in the inverted position), not only to facilitate lifting the unit out of an assembly but also to enable the unit to be stood upsidedoawn on the handles to permit of ready access to the valves in the channel. The form of unit described above may conveniently be made out of a light alloy casting. It may be formed as a single integral casting or it may be formed in a number of sections, for example two end sections joined by a central section Making the unit in sections facilitates the construction of units having a number of different types of valve holders since sections suitably formed may be readily joined together. As indicated above unit construction is particularly applicable to radar display systems and it has been found particularly advantageous to use a number of small units in such a radar display It will be appreciated that many of the more complex radar systems require very accurate control of voltages and the like and it is common practice in such systems to utilize complex circuits employing servo loops for maintaining the required stability It has been found particularly con

70 venient to construct each servo lcop as a sepgrate unit which may thus be readily replaced if there should be any fault in the unit Each unit is preferably provided with a number of readily accessible test points, e g for the 75 input and output signals, to which test instruments can be connected. The following is a description of two embodiments of the invention, reference being made to the accompanying drawings in 80 which:Figure 1 is a side elevation of a unit for use in electronic equipment, Figure 2 is an end view of the unit of Figure 1, 85 Figure 3 is an underside plan view of the unit of Figure 1, Figure 4 is a section along the line 4-4 of Figure 3, Figure 5 is a side elevation of another con 90 struction of unit shown in its mounting, part of the unit being cut away to show internal details, and Figure 6 is a plan view of the unit of Figure 5 95 Referring to Figures 1 to 4, there is shown a unit in the form of an inverted U-shaped channel, in the form of a plate 10 with the two downwvardly-extending side,valls 11 which, at their lowest ends, are provided with 100 outwardly-extending flanges 12 This unit is formed of sheet metal and is strengthened by flanges 13 on each end of the unit, these flanges 13 enabling the channel unit to be bolted to a pair of end plates 14 which are provided 105 wlth two apertures 15, 16 The unit is carried on a base in the form of a tray 17 (shown in chain-dotted lines in Figure 4) having a pair of threaded bushes 18 which may be engaged by a pair of screw rods 19 securing 110 the unit in position on the base Mounted on the base tray 17 are a pair of multi-hole sockets for engaging two plugs 20 on the underside of the unit The screw rods 19 are provided with conical ends for assisting in 115 the locating of the unit correctly on the base 17 to permit of the plug pins entering their respective socket holes before the rods 19 are screwed down. All the valves 25 to be carried on the unit 120 are mounted on the underside of the plate 10. Resistors and condensers are, as far as possible, mounted on the outer side of the unit between the side walls 11 and the flanges 12. Some of these components, as indicated at 125 26, are arranged between soldering tags 27 stretching along the upper side of the walls 11 and soldering tags 28 arranged at the outer ends of the lower flanges 12 Smaller components may be arranged, as indicated at 29, 130 784,993 the position shown in Figure 6 in which the plug engages the socket To ensure proper alignment of the plug pins, locating pegs 53 are provided on the end wall 45 which engage in corresponding holes on the unit just before 70 the plug pins enter their socket In the arrangement of Figures 5 and 6, the plates 45 and 4,8 are provided with apertures similar to the apertures 15, 16 of Figures 2 and 4 so enabling, when the unit is disposed 75 between an inlet and an outlet

for an airstream, the valves which are mounted on the underside of the plate 40 to be cooled without air being blown over the resistors and condensers which, as far as possible, are 80 mounted on the outside of the unit between the side walls 41 and the flanges 42 in a similar manner to that illustrated in Figures 1 and 4. Instead of providing a forced air-stream 85 as described above, in some cases the units may be mounted with the channels vertical for cooling the valves by convection. It will he seen that, in each of the two arrangements illustrated in the drawings, the 90 unit is readily removable from its mounting and, that, when so removed,, easy access is obtained to all the components for servicing. Furthermore, the valves may readily be cooled without having any air-stream over the com 95 ponents on the outer sides of the units.

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* GB784994 (A)

Description: GB784994 (A) ? 1957-10-23

Improvements in or relating to electrical heating apparatus

Description of GB784994 (A)

PATENT SPECIFICATION Date of filing Complete Specification: Aug 26, 1955. Application Date: Sept I, 1954. No 25399/54. \ f io/lo Complete Specification Published: Oct 23, 1957. Index at acceptance:-Classes 39 ( 3), H( 1 E: 2 E 4 E: 2 Ell); and 44, BBX. International Classification:-E 05 c H 05 b.

COMPLETE SPECI;FICATION Improvements in or relating to Electrical Heating Apparatus I, HENRY HERBERT Go LDSTAUB, A.M I E E, of 641 Mount Pleasant Road, Chigwell, Essex, of British nationality, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it S to be performed, to be particularly described in and by the following statement: - This invention relates to electrical heating apparatus and is concerned with electrical heating panel assemblies for employment in space heating, domestically or otherwise. According to an aspect of the present invention, there is provided an ekectrical heating panel assembly comprising a frame which supports therewithin a panel consisting of two sheets of rigid electrically insulating material having an electrical heating resistance located between them, such sheets being bonded together. According to another aspect of the present invention, there is provided an electrical heating panel assembly, wherein there is supported within a frame a panel consisting of two sheets of rigid electrically insulating material with an electrical heating resistance located between them, such sheets being bonded together, and wherein at least one face of the panel is set back from the corresponding face of the frame such that when the frame is placed against a wall with said one face presented to the wall there will be a space for air between that face and the wal, and, wherein there is a gap between an edge of the panel and the frame, whereby air can pass, through said gap, between said space and the surrounding air. For a better understanding of the invention a constructional form thereof will now be described by way of example with reference to the accompanying drawings in which:Figure 1 is a front elevation, of a heating panel assembly, Figure 2 is a section taken along the line II 4 I of Figure 1, and Figure 3 is a fragmentary, front elevation showing how two of the assemblies may be joined one to the other. l Referring first to 'Figures 1 and 2, a heating panel assembly consists of an oblong rectangular frame, which may comprise four wooden members 1, 2, 3 and 4 moulded to a section to afford a pleasing appearance 'For reasons that will appear hereinafter, the two shorter frame members 2 and 4 are butted onto the ends of the two longer frame members 1 and 3. The frame is arranged to receive a heating panel 5 ' which is also oblong rectangular in shape One face of the panel is set back from the corresponding face of the frame in order to provide, when the face is presented to the wall, an air-space between the panel' and the wall The longer dimension of the panel is equal to the internal longer dimension of the frame The shorter dimension of the panel is less than the internal shorter dimension of the frame, so that when the panel is

placed in the frame whilst the frame is held, with one of its longer sides uppermost, there is a gap 6, 7 at top and bottom between the panel and the frame, The gaps are provided in order that air may circulate between the above-mentioned air-space and the surrounding atmosphere, The panel 151 consists of two sheets '8 and 9 of flame proof hardboard (in accordance with British Standard 276 2 A) The two sheets of hardboard are placed together with their smooth surfaces outermost after an electrical heating resistance has been included therebetween The sheets are united by synthetic resinous adhesive, the adhesive being cured by heat and pressure, In Figure 1 the sheet 9 has been shown partially broken, away to reveal the sheet '8, beneath. Prior to the bonding together of the two sheets '8 and 9 of hardboard, the electrical heating resistance is laid upon the inside of one of them In the illustrated constructional example the electrical heating resistance is provided by a metallic strip 10 The strip 10 is first laid near to one of the longer edges of one of the hardboard sheets as at 10 A, so as to be substantially parallel with such edge and to extend from near one end of such edge 784,994 towards a location near to the other end thereof At such other end, the strip is bent upwardly along a line which is about 45 to the longitudinal extent of the strip, and is then folded downwardly upon itself whereupon the strip is laid upon the surface of the sheet for a short distance as at 10 B parallel with the adjacent shorter side of the sheet Thereafter a similar fold is produced so that the strip then returns as at O l C in a direction parallel with the longitudinal edge of the sheet towards the other end thereof whereafter the strip has a similar double fold and returns towards the other end of the strip once more upon a line parallel to the longer edge This process is continued until substantially the whole surface of the sheet is covered with the strip which follows a sinuous path save for a marginal border (in Figure 1 the course followed by the strip is indicated mainly by a single dotted line for simplicity of illustration) By appropriate choice of the distance between the described folds in the strip the sheet has the strip arranged to be substantially uniformly distributed over its surface area After the strip has been applied in the manner described, the two ends 11 and 12 thereof are brought to an adjacent location and, are provided with terminal posts 13 and 14 located in a terminal box 15 (see Figure 2) The bends in the strip are rolled down to ensure that there is substantially no bulging. After the two sheets '8 and 9 have been bonded together with the electrical resistance strip 10 therebetween, a flat composite panel is producedl with the two terminal posts 13 and 14 available for connection to a source of electrical power When the posts are connected to such a source, the resistance strip causes heat to be

generated and the panel; becomes correspondingly warm Because of the uniform distribution of the strip 10 between the two sheets 8 and 9 comprising the composite panel 5, a substantially uniform generation of heat occurs. The panel 5 is mounted in, the frame 1, 2 3 and 4 by a mounting means of simple but effective construction The mounting means will now be described It is assumed for the purpose of description that the frame is disposed with one of its longer sides uppermost whilst the frame is retained in a vertical plane. The upper side member 1 of the frame hasupon its lower longitudinal inner face, a plurality of Iocating blocks 20 The blocks may be three in number, one at each end of the upper side member, and one in the centre thereof. The blocks are fixed to the upper side member and extend into the frame, the lower face of each block being grooved in the longitudinal direction of the frame, so that the grooves are aligned and can receive the upper longitudinal edge of the panel A groove 21 of one of the blocks 20 can be seen in Figure 2 The blocks 20 extend the full horizontal depth of the frame But the aligned grooves 21 are nearer to one side of the frame,which is intended to be the front of the frame, than the other side of the frame intended to be the rear The rear side may have a backing 70 strip 22 applied thereto or may simply be arranged to be supported adjacent the wall of a room or the like where the panel assembly is to be mounted. Further blocks 23, similar to the blocks 20, 75 are provided for location upon the upper inner face of the lower side member 3 of the frame, such blocks 23 not, however, being fixed thereto The lower blocks 23 differ from the upper blocks 20 in that the aligned grooves 80 24 therein are considerably wider than is necessary for the reception of the lower edge of the heating panel Moreover, the lower blocks do not extend the full depth of the surface of the lower frame member 3 on 85 which they are located When each lower block 23 is placed so that its front face is in register with the froint face of the lower side member, and with the lower edge of the heating panel entered in the groove 24, the heating 90 panel lies in a vertical plane when the lower edge of the panel is held in the grooves 24 in contact with the side walls of the grooves nearer the front of the frame Because the grooves 24 in the lower blocks 23 are 'wider 95 than is necessary to receive the panel, the rear portion of each groove is left free To hold the lower blocks 23 in their panelretaining position, there are three claw-like retaining members 25 secured to the lower 100 side member 3 of the frame Each such clawlike retaining member consists of an upstanding portion 25 A flush with the rear side of the frame and secured to the upper inner face of the bottom side

member, the upper end of 105 each such portion being forwardly extended at B towards the front of the frame, and having a downwardly extending lip 25 C The lip is such as to fill that portion of the groove 24 in a lower block 23 that is not occupied 110 by the lower 'edge of the panel when the latter is in position in the lower block. To mount a heating panel in the frame, the upper longitudinal edge of the panel is first introduced into the groove of the upper 115 series of blocks 20 The lower edge of the panel is then brought to lie against the lipped ends 25 C of the claw-like members 25, and thereafter the lower blocks 23 are placed in position with the lower edge of the panel 120 entered in their relatively wide grooves, the lower blocks being at that time displaced away from their associated claw-like retaining members The lower blocks 23 are then slid along the lower edge of the panel to a posi 125 tion where each lower block co-operates with its c Iaw-like retaining member 25, the lip of the latter entering the groove in the block and thereby retaining the lower edge of the panel in position Preferably each lower block 130 784,994 edge of the panel and the frame, whereby air can pass, through said gap, between said space and the surrounding air. 3., An assembly as claimed in claim 1 or 2, wherein said sheets consist of flame-proof 70 hardboard 4 An assembly as claimed in any preceding claim, wherein the electrical heating resistance consists of a wire 'or strip arranged to follow a sinuous path so as to be substantially 75 uniformly distributed over the panel An assembly as claimed in any preceding claim, wherein the frame is generally rectangular in shape and includes a pair of Oppositely situated frame members which each 80 carry on their inner faces several blocks having aligned grooves for reception of opposite edges of the panel whereby the latter is retained in the frame 6 An assembly as claimed in claim 5, 85 wherein the blocks associated with one:of said frame members are fixedly secured to such member whilst the blocks associated with the other of said f Trame members are formed with grooves wider than is necessary for the recep 90 tion of the panel edge, said grooves being engageable also by claw members fixedly attached to said other frame member, the arrangement being such that when the blocks with the wider grooves have had the panel 95 edge entered in the grooves these blocks can be slid along the panel edge until the appropriate claw-like member also, enters the groove and thereby locates the block with the panel supported in its groove 100 q A composite heating device comprising at least two of the electrical heating panel assemblies as claimed in claim 51 or 6, the assemblies being arranged with their panels in end-to-end substantially co-planar relation 105 ship, the frame members which would otherwise separate the panels being removed whilst the remaining frame members which are in prolongation of each

other are joined by a dowel connection or the like 110 8 A heating device as claimed in claim 7, wherein the junctions between the panels are covered and supported by I-section strip 9 t A heating device as claimed in claim 7, wherein the junctions between the aligned 115 frame members are covered by I-section cappings. An electrical, heating panel assembly substantially as hereinbefore described with reference to Figures 1 and 2 of the accom 120 panying drawings. 11 A composite heating device comprising at least two of the electrical heating panel assemblies as claimed in dclaim 10, substantially as hereinbefore described with reference 125 to Figure 3 of the accompanying drawings. IASELTINE, LAKE & CO, 28, Southampton Buildings, Chancery Lane, London, W C 2, Agents for the Applicant. and claw-like retaining member are of complementary shape, so that they fit closely together when one is slid into the other If so desired, wedge surfaces may be formed to ensure that when a lower block is co-operating with the associated claw-like retaining member, the possibility of accidental displacement is reduced or eliminated. In order to allow the horizontal extent of the assembly to be simply altered, the shorter frame members 2 and 4 are made readily detachable from the longer frame members 1 and 3 Upon removal of one of the shorter frame members, the longer frame members can be effectively extended by joining in alignment therewith two, similar longer frfame members of a second assembly from which the corresponding shorter frame member has been removed In Figure 3 there is shown part of a first assembly having a frame member 1 A and heating panel 15 A, and a second assembly having a corresponding member l B' and panel B The longer frame members 1 A and 1 B are butted one to the other with the interposition of dowel pins 30, or the like The junction between the two heating panels 5 A and 5 B of the two frame assemblies is supported and obscured with the aid of a strip of I-section material 31, the web of the I-section material lying between the co-planar heating panels, whilst the flanges of the I-section extend over the surfaces of the two adjacent panels, The butting longitudinal frame members 1 A and l B are preferably likewise covered with I-section cappings 32, the webs of which allow passage of the dowel pins 30, and the flanges of which extend over the locations of junction of the longitudinal side members of the two frames It will be appreciated that several, assemblies may be joined one to the other 'so as to give 'a composite heating device of any desired length. Although in the illustrated construction use is shown of a strip to form the heating resistance, it is to be understood that a wire or wires could be substituted.

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* GB784995 (A)

Description: GB784995 (A) ? 1957-10-23

Improvements in and relating to screens and sieves

Description of GB784995 (A)

COMPLETE SPECIFICATION Improvements in and relating to Screens and Sieves We, THOMAS DE LA RUE AND COMPANY LIMITED, a company organised under the laws of Great Britain, of Imperial House, 84-86 Regent Street, London, W.1, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to screens and seives and in particular to jigger screens which are used in coal washing plant to remove water from coal slurry tailings from the main plant. Such jigger screens are normally mounted in sets on vibratory frames, the wet slurry being introduced onto one end of the set of screens and being moved therealong Iby vibration from the one end to the other, where the partly dried slurry falls onto a second set of jigger screens or onto a delivery conveyor. Jigger screens at present in use are commonly made of an assembly of brass wire and steel rods but such screens have the disadvantage that they are liable to corrosion, particularly due to the use of dissimilar metals under conditions favourable to electrolytic action. In addition such screens are heavy in weight and consequently handling

difficulties arise when assembly of the screens themselves: lor of ,the screens in their frames takes place under the restricted conditions which often occur in coiai washing plants. One object of this invention is to produce a lightweight, strong and durable screen or seive which will not be liable to corrosion. Another object of the invention is to produce a screen or sieve which can be easily assembled and disassembled so as to facilitate cleaning and the replacement of those parts which are subject to considerable wear and tear. A screen or sieve, according to the present invention, comprises a plurality of individual longitudinal slats mounted on edge in parallel relationship to each other, each slat having its top and bottom edge parallel and one side at right angles thereto, the other side being tapered downwardly for at least part of its depth, and a number of spacing elements on said other side at regular intervals therealong, each spacing element having an outer face at right angles to the top and bottom edges and increasing fractionally the width of said top edge of each slat for the length of each spacing element, so that there is provided between adjacent slats a number of longitudinal slots each of whose length is determined by the distance between the spacing elements on each slat, and the width of each slot being a minimum at the top and increasing downwardly in accordance with the tapered side of each slat. The spacing elements may be formed integrally with the said other side of each slat, or may be formed separately and located in suitably shaped recesses in the side of each slat. Preferably the slats are secured together in correct relationship by means of cross-ties which pass through holes formed transversely of the slats through the spacing elements. The cross-ties may be pins or rods and may pass through holes formed in rigid side members to which they are secured by threaded anti-vibration nuts so as to clamp the slats firmly between the side members. Preferably stiffening members are provided in the assembly of slats forming the screen, the members being of rectangular cross section and being arranged parallel to the slats at convenient intervals to give added strength to the screen. Preferably the slats are supported at their ends by means of transverse end members of L-shaped cross section, which support the ends of the slats and which are screwed to the side members and to the stiffening members, a mortise and tenon joint being provided in addition, between slaid transverse end members and stiffening members. Preferably the tapered side of the slat is formed with la taper sufficient to ensure adequate space for the removal of all material

which passes through the slots between adjacent slats, and in order to avoid undue fineness of the bottom edge of each slat, the taper is stopped short of the bottom edge, the rebeing portion of the depth of the slat on the tapered side being parallel to the straight side of .the slat The tapered side of each slat may have a small portion of Its depth, adjacent the top edge of the slat, formed with a face parallel to the straight side of the slat so that the taper does not extend up to the top edge of the slat This feature increases the life of each slat by avoiding a keen edge which would soon become worn and mean replacement of the slat The slats are preferably made from cotton or other fabric, ,asbestos, glass fibre cloth, glass fibre mat or other suitable material impregnated with phenol formaldehyde condensation product resins or other thermosetting resin, impregnated fabric strips being assembled in a mould corresponding to the desired shape of the slat and consolidated under the action of heat and pressure. It is lalso possible to machine the slats to the required shape from strips obtained from boards produced by the consolidation of resin impregnated fabric in a platen press. The longitudinal sides of the screen, the transverse L-shaped end members, and the stiffening members are all also preferably m;ade from a laminated plastic material, sides and members of the desired shape and size being machined from boards obtained by consolidation of resin impregnated fabric in a platen press. The invention is illustrated diagrammatic- ally in the drawings accompanying the provisional specification, in which: Figure 1 is a perspective view of one form of slat, Figure 2 is an end view in section of the slat shown in Figure 1, between any tpiro spacing elements, Figure 3 is an exploded perspective view of a portion of the screen, using withe slats shown in Figures 1 .and 2, and in the accom- paning drawings in which:- Figure 4 is a perspective view of an- alternative form of slat, and Figure 5 is an exploded perspective view of a portion of the screen showing a modi fication Referring to Figures 1 and 2 of the draw- ings, a slat made of a synthetic resin material has top and bottom parallel edges 2 and 3 and one side 4 at right angles to these edges. The other side of the slat has a portion 5 which is parallel to the side 4, and then has a tapered portion 6 and a further straight portion 7 which is parallel to the side 4. The slat at the bottom edge is of reduced thick- ness compared to its top edge.

At each end of the slat and at regular ater- vats along its length there are formed, integral with the slat, spacing elements having outer faces 8 parallel to the side 4. The width of the top edge 2 of the slat is increased for the length of each of the spacing elements by a desired amount according to the thickness of the spacing element, This fact being determined by the width of the slots desired in !an assembled screen. In a preferred construction of slat the maximum width (i.e. along the length of each spacing element) of Ithe top edge 2 is threesixteenths of an inch, the width of the bottom edge 3 being seven-sixty-fourths of an inch and the side 4 ;being nine-sixteenths of an inch deep. The parallel portion 5 of the tapered side is one-thir.tysecond of an inch deep, the included angle of taper being 12', and the lower parallel portion 7 of the tapered side is three-sixteenths of an inch deep. The spacing elements are formed -along the slat four inches apart, and along the length of each spacing element the width of the top edge 2 exceeds the width over the remainder of the length of the slat by .015". Through the centre of each spacing element a hole 9 is bored and, referring to Figure 3, a plurality of slats are assembled, with tube spacing elements of one slat against the side 4 of an adjacent slat, to form a screen. The assembly is held together in correct relationship by means of brass or stainless steel cross-ties 10 which pass through the holes 9 and are secured to rigid Side pieces 11 of rectangular cross-section by means of washers 12 'and antivibration nuts 13. To give added strength to the screen and to minimise bowing one or more stiffening elements 14 of rectangular cross-section are included in the slat assembly at desired intervals. In the alternative form of slat shown in Figure 4, the spacing elements are shown as being separate from the slat instead of integral therewith, as in the embodiment shown in Figures 1 to 3. The slat of Figure 4 is formed in the same manner as the slat shown in Figure 1, but without the integrally formed spacing elements so that the tapered portion 6 is continuous throughout the length of the slat Recesses 15 are subsequently machined in the tapered portion 6 where desired to receive, with a close fit-spacing elements 1-6 in the form of recangular washers of a uniform thickness, which are sufficient to increase the width of the top edge 2 of the slat for the length of each recess by the desired amount. In the modified assembly of a plurality of slats shown in Figure 5, the slats, which may be formed as shown in Figure 1 or Figure 4, are assembled and held together in correct relationship to form a screen

or sieve in the same manner las shown in Figure 3, by means of the cross-ties 10, rigid side pieces 11 and nuts 13, together with the stiffening elements 14, only one of which is shown in Figure 5. In order to prevent the slats from sagging, their ends are supported by L-shaped end members 117, only one loif which lis shown in section in Figure 5, which end members are secured, by screws 18, to the ends of each rigid longitudinal side piece 11, which are extended for this purpose, and by screws 19, to the ends of the stiffening members 14 which are extended for this purpose, and are connected to the L-shaped end members by a mortise and tenon joint as shown at 20. What we claim is: 1. A screen or sieve comprising a plurality of individual longitudinal slats mounted on edge in parallel relationship to each other, each slat having its top and bottom edge parallel and one side at right angles thereto, the other side being tapered downwardly for at least part of its depth, and a number of spacing elements on said other side at regular intervals therealong, each spacing element having an outer face at right angles to the top and bottom edges and increasing fractionally the width of said top edge of each slat for the length of each spacing element, so that there is provided between adjacent slats a number of longitudinal slots each of whose length is determined by the distance between the spacing elements on each slat, and the width of each slot being a minimum at the top and increasing downwardly in accordance with the tapered side of each slat. 2. A screen or sieve as claimed in claim 1 wherein the spacing elements 'are formed integrally with the side of each slat. 3. A screen or sieve as claimed in claim 1 wherein the spacing elements are formed separately from each slat and are located in suitably shaped recesses in the side of each slat. 4. A screen or sieve as claimed in claim 1, 2 or 3 wherein the plurality of slats are secured together in correot relationship by means of cross-ties, which pass through holes formed transversely of the slats through the spacing elements. 5. A screen or sieve as claimed in claim 4 wherein the cross-ties are pins or rods which are secured to rigid longitudinal side members, serving to clamp the slats firmly therebetween. 6. A screen or sieve as claimed in any of claims 1 to 5 wherein stiffening members are provided in the assembly of slats arranged parallel to the 'slats at intervals throughout the assembly. 7. A screen or sieve as claimed in claim 6 wherein the ends of the plurality of slats are supported by end members of L-shaped cross section, which are secured to the ends of the stittening members and to the ends of the rigid side members. 8. A screen or sieve as claimed in any of claims 1 to 7 wherein the

tapered side of each slat is stopped short of the bottom edge of the slat so that the remaining portion of the depth of the slat on the tapered side is parallel to the straight side of the slat. 9. A screen or sieve as claimed in any of claims 1 to 8, wherein the tapered side of each slat does not extend completely up to the top edge lof the slat, la small portion of the depth of the tapered side, adjacent the top edge of the slat, being formed with a face parallel to the straight side of the slat. 10. A screen or sieve constructed and arranged substantially as described herein and as shown in Figures 1 to 3 of the drawings accompanying the provisional specification, and in Figure 4 or Figure 5 of the accompanying drawings. PROVISIONAL SPECIFICATION Improvementsl in and relating to Screens and Sieves We, THOMAS IDE LA RUE AND COMPANY LIMITED, a company organised under the laws of Great Britain, of Imperial House 84-86 Regent Street, London, w.1, do hereby declare this invention to be described in the following statement: This invention relates to screens and sieves and in particular to jigger screens which are used in coal washing plant to remove water from coal slurry tailings from the main plant. Such jigger screens are normally mounted in sets on vibratory frames, the wet slurry being introduced onto one end of the set of screens and being moved therealong by vibration from the one to the other, where the partly dried slurry falls onto a second set of jigger screens or onto a delivery conveyor. Jigger screens at present In use are com- monly made of an assembly of brass wire and steel rods but such screens have the disadvantage that they are liable to corrosion particularly due to the use of dissimilar metals under conditions favourable to electrolytic action. In addition such screens are heavy in weight and consequently handling difficulaties arise when assembly of the screens themselves or of the screens in their frames takes place under the restricted conditions which often occur in coal washing plants. One object of this invention is to produce a lightweight, strong and durable screen or sieve which will not be liable to corrosion. Another object of the invention is to produce a screen or sieve which can be easily assembled and disassembled so as to facilitate cleaning and the replacement of those parts

* GB784996 (A)

Description: GB784996 (A) ? 1957-10-23

Improvements in or relating to the treatment of webs of paper and like sheetmaterial

Description of GB784996 (A)

'I A H q>- _,, PATENT SPECIFICATION - Date of filing Complete Specification Sept 23, 1955. Application Date Oct i, 1954. 784,996 No 28396154. By k Complete Specification Published Oct23, 1957. Index at Acceptance:-Class 100 ( 1), E( 4 B: 6 HX). International Classification: -B 41 g. COMPLETE SPECIFICATION Improvements in or relating to the Treatment of Webs of Paper and like Sheet Material ^ r;tish at at least one edge or surface adjacent thereto l ttinsw the web into SPECIFICATION NO 784 996 INVENTOR EDWARD VEAR By a direction given Under Section 17 ( 1) of the Patents Act 1949 this application Proceeded in the naie of Ozaild Company Limited, a British company, of 62, London Wall, London, E C 2 Act 1949 this application THE PATENT OFFICE, 1 lst January, 1958 methods -(anc apirat xmethods) in which material is first treatea,, example coated with a chemical, and wound into reels and subsequently unwound from those reels and cut, on a suitable machine such as a cross cut sheeting or roll cutting machine, into predetermined lengths. In a length of material there are often defective sections which may have been present in the original material or which have arisen during an initial treatment of the material such as coating Thus, during a subsequent operation e g one in which the material is cut into predetermined lengths, some of those lengths may contain defective portions and any such lengths must be removed from the other lengths. It is an object of the invention to provide means to facilitate the removal of such defective lengths. The invention provides a method of producing, from a continuous web of material containing a defective section or sections, a number of

predetermined lengths of material without defective sections, which method comprises applying marks or indications designated "pilot markings" to the or each defective portions of the web, and subsequently applying to portions of the web carrying pilot markings, marks or indications designated "monitoring markings" which will be visible lPrice 3 s 6 d l DB 0234 S/1 ( 3)/383 e 150 1/e 58 R ing (e gmechanically) mne lu non-defective lengths as they are cut and con 65 tinning to cut said lengths until the desired number has been recorded, regardless of the number of lengths containing defective portions Preferably the number of lengths containing defective portions is separately 70 recorded. Alternatively, the total number of the lengths cut from the web may be recor ded, the number of lengths containing defective portions separately recorded and an allowance 75 made in the total for the number of lengths containing defective portions. The continuous web of material may be reeled, the pilot markings having been applied during the manufacture or subsequent treat 3 O ment of the material These markers conveniently comprise tabs inserted in the reel as the material is being wound. Alternatively of the pilot markings to denote defective sections may be applied to the 85 material itself Such markings may consist of uninterrupted bands of colour or other substance which will cause a response in a suitable electrical device Preferably the bands are applied adjacent to an edge of the web of 90 material. The invention further provides apparatus m-;,C,,;s,. PATENT SPECIFICATION - Date of filing Complete Specification Sept 23, 1955. f /: Application Date Oct1, 1954 No 26 2 / C Complete Specification Published Oct23, 1957. Index at Acceptance:-Class 100 ( 1), E( 4 B: 6 HX). International Classification: -B 41 g. COMPLETE SPECIFICATION Improvements in or relating to the Treatment of Webs of Paper and like Sheet Material We, OZALID COMPANY LIMITED, a British Company, and EDWARD VEAR, a British Subject, both of 62, London Wall, London, E C 2, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: - This invention comprises improvements in or relating to the treatment of webs of paper and like material and is concerned with processes in which a web of material (e g. unwound from reels) is cut into lengths of predetermined size More particularly, but not exclusively, the invention is concerned with methods (and apparatus for effecting such methods) in which material

is first treated, for example coated with a chemical, and wound into reels and subsequently unwound from those reels and cut, on a suitable machine such as a cross cut sheeting or roll cutting machine, into predetermined lengths. In a length of material there are often defective sections which may have been present in the original material or which have arisen during an initial treatment of the material such as coating Thus, during a subsequent operation e g one in which the material is cut into predetermined lengths, some of those lengths may contain defective portions and any such lengths must be removed from the other lengths. It is an object of the invention to provide means to facilitate the removal of such defective lengths. The invention provides a method of producing, from a continuous web of material containing a defective section or sections, a number of predetermined lengths of material without defective sections, which method comprises applying marks or indications designated " pilot markings " to the or each defective portions of the web, and subsequently applying to portions of the web carxying pilot markings, marks or indications designated " monitoring markings " which will be visible lPrice 3 s 6 d l at at least one edge or surface adjacent thereto of the lengths when cut, cutting the web into a number of predetermined lengths, arranging said lengths in such manner that the monitoring markings are visible, and removing those lengths bearing monitoring markings. Preferably the web is cut up into a plurality of sheets which are stacked and the marked defective sheets which are selected by inspection of the edges or the surfaces adjacent thereto removed from said stack. According to a feature of the invention the monitor markings may comprise one or more continuous and visible coloured bands applied to the surface of the material. According to a further feature the method may include the steps of automatically recording (e g mechanically) the number of only the non-defective lengths as they are cut and continuing to cut said lengths until the desired number has been recorded, regardless of the number of lengths containing defective portions Preferably the number of lengths containing defective portions is separately recorded. Alternatively, the total number of the lengths cut from the web may be recorded, the number of lengths containing defective portions separately recorded and an allowance made in the total for the number of lengths containing defective portions. The continuous web of material may be reeled, the pilot markings having been applied during the manufacture or subsequent treatment of the material These markers conveniently comprise tabs inserted in the

reel as the material is being wound. Alternatively of the pilot marlings to denote defective sections may be applied to the material itself Such markings may consist of uninterrupted bands of colour or other substance which will cause a response in a suitable electrical device Preferably the bands are applied adjacent to an edge of the web of material. The invention further provides apparatus 784,996 1396154. ' j'1at. when used in carrying out the method according to the invention as described above, said apparatus being an attachment for or a component of, a machine for cutting predetermined lengths from a continuous web of material and comprising colour applying means operable to apply one or more continuous bands of visible colour to the material before cutting, said band or bands constituting the monitoring markings aforesaid, and actuating means for bringing the said colours-applying means into operation responsive to pilot markings previously applied to defective sections of the web, in such manner as to cause said band or bands of visible colour to be applied to the sections of the web bearing such pilot markings. The apparatus may be manually controllable Alternatively, there may be provided means responsive to markings or signals on, or associated with, the material itself, for automatically rendering the device operative or inoperative. Said responsive means may comprise a photo-electric cell responsive to light changes caused by markings on the web of material and an electro mechanical means controlled by the response of the cell to render the visible colour applying device operative or inoperative. The apparatus may also include a counter for predetermined lengths as they are cut and means for rendering the counter inoperative to count lengths cut from material to which visible colour has been applied, or alternatively to count lengths cut from material to which visible colour has not been applied. A second counter may also be provided, which counter is arranged for operation when the first counter is inoperative. The invention further includes a combination of apparatus components when used in carrying out the method according to the invention as set forth hereinbefore, said combination comprising a coating machine for applying a lightsensitive coating composition to a web, means for applying pilot markings to denote the beginning and end or duration of a defective section or sections of the web, said means being located adjacent to the web immediately after a device for removing excess coating composition from the web, and further pilot marking applying means located adjacent a drying device for drying the coated web. Said means may comprise a roller adapted to apply when in operation an

uninterrupted marking band along the length of the material adjacent to one edge thereof. Preferably at least two means for applying preliminary markings are provided. The following is a description by way of example of a method and apparatus in accordance with the present invention Reference is made to the accompanying drawings in which:Figure 1 is an end elevation of apparatus for applying marking to detective sections of a web of material in a coating machine prior to reeling and subsequent processing in a cutting machine; Figure 2 is a front elevation of the apparatus shown in Figure 1; Figure 3 is a section on the line 3-3 of Figure 2; Figure 4 is a plan view of the apparatus; Figure 5 is an end elevation of apparatus for marking defective sections of a treated web of material prior to a cutting operation; Figure 6 is a plan view of the apparatus shown in Figure 5; Figure 7 is a mainly diagrammatic end elevation showing the apparatus illustrated in Figures 5 and 6 mounted on a cross cut sheeting machine; and Figure 8 is a diagrammatic representation of a machine for producing from a web of material rolls of material of predetermined length including apparatus for marking defective sections of the material. These embodiments are described in connection with a process in which webs of paper are coated with a light-sensitive composition and then subsequently cut into sheets or rolls for use for photo copying purposes. In order that the invention may be more clearly understood it is necessary to describe in broad outline the basic stages of such a method, and also the apparatus for effecting it. A web of paper delivered from a reel is 100 passed over coating rollers whereby it is coated with a light-sensitive solution After it has passed over the coating rollers the paper is conveyed vertically upwards past a device the purpose of which is to remove excess coating 105 solution which falls back into a bath in which the rotating coating rollers are partially immersed The paper, which is now coated on one side with the light-sensitive solution, then passes through a suitable unit to dry the coat 110 ing, and it may also undergo other conventional treatment, for example, to modify the texture of the paper, and finally is re-wound into a reel. During a coating operation it is found that 115 sections of the paper may be imperfectly coated or the final quality otherwise impaired. For example, a piece of grit or other foreign matter may come into contact with the surface of the paper, thus resulting in an uneven coat 120 ing Furthermore during a coating operation test pieces are removed and the sections of paper thus affected are unsuitable for photocopying purposes One practice which has been adopted in the past

is for the operator to 125 insert tabs as side-markers in the reel of rewound coated paper, which tabs alone signify the beginning and end of defective sections of paper. The reels of coated paper are then removed 130 -2 784,996 784,996 to further apparatus where for example, they may be cut either into sheets (i e on a cross cut sheeting machine) or made into smaller rolls of predetermined length. As has been mentioned above, one practice previously adopted to mark the defective sections during a coating operation has been for the operator merely to insert tabs in the reel of coated paper as it is wound According to one of the features of this invention, means are now provided whereby markings are made on the web of paper during its processing in the coating machine, these markings subsequently serving to actuate a further marking device associated with a sheet or roll cutting machine. One form of such apparatus hereinafter referred to as a " pilot unit " for marking the defective sections of the paper during the coating operation will now be described with reference to Figures 1 to 4 inclusive of the accompanying drawings. The pilot unit comprises two side frames 11 between which is mounted a small conventional printing unit comprising an ink trough 12, an inking roller 13, an ink distributing roller 14 and a printing disc roller 15. The unit between the rigid side frames 11 is arranged to be mounted across the width of a coating machine on two horizontal rods 16 and 17 Passing through the upper part of the side frames 11 is a rotating shaft 18, having along its length a key-way 19, which also passes through the upper gear wheel of a gear train 20 This gear train 20 drives the rollers of the printing unit through the medium of a sprocket 21 mounted on the rotating shaft 18 which is driven by means of a chain and sprocket on a suitable prime mover on the coating machine Preferably the peripheral speed of the printing disc roller 15 is synchronised with the speed of travel of the web and variable therewith. The horizontal rods 16 and 17 and rotating shaft 18 are mounted across the coating machine on brackets 22 and 23 The printing disc roller 15 has a limited vertical movement bringing it into or out of printing position, and is actuated by an electro-magnetic device 24 through a suitable linkage 25, 26 In the printing position the roller 15 is in contact with the coated side of the paper when passing over a suitably positioned roller on the coating machine. Two pilot units are preferably used in the coating machine One is mounted at a position just above the device for removing excess coating solution The second unit is located at the other extremity of

the machine, i e in a position to operate on the material after it has been dried, but before it is wound into reels. The ink used in the unit in the first mentioned position should preferably be a moisture setting ink, whereas that used in the unit in the second position will normally be an aniline printing ink Push button means for bringing the units into operation are located at various positions on the coating machine, these positions being readily accessible to the operator. Very often the reason for there being a defective portion in the coated material is that a 70 small piece of dirt becomes lodged in the device for removing excess coating solution. This will be seen by the operator who will then take the necessary steps to bring the unit located just above this device into action and 75 mark the defective portion of the material with a band of ink On the other hand tests may have been made on the coated material, or other defects may have arisen subsequent to the passage of the material past the first men 80 tioned unit, in which case the second unit would be brought into operation to mark the material. The pilot unit or units may also be connected (e g electrically) with a counter or 85 counters (not shown) adapted to record the number and/or yardage of defective and/or non defective sections contained in the reel of paper being coated or in the reels coated over a period 90 The markings made by the unit above described serve to initiate operation of a further unit (hereinafter referred to as a " monitoring unit ") which is associated with a machine for cutting the material A monitoring unit 95 designed for use with a cross cut sheeting machine will now be described with reference to the Figures 5, 6 and 7 of the accompanying drawings The monitoring unit consists of two brackets 27 between which is mounted a 100 printing unit comprising an ink trough 28, an inking roller 29, an ink distributing roller 30 and printing disc rollers 31 The printing disc rollers 31 are mounted for limited vertical movement bringing them into or out of con 105 tact with the web of material 32 (shown in chain lines) as it passes over the surface of a printing impression roller 33 The printing disc rollers 31 are also mounted such that the spacing between each roller and also the over 110 all spacing may be adjusted. After leaving the printing position, the web of material 32 passes over a roller 34 which may be mounted in any one of three positions, 35, 36 and 37 The purpose of these alterna 115 tive mounting arrangements is to alter the period of time and length of travel of the web between the printing position and the cutting position on a sheeting machine, thereby allowing a greater or less time as may be necessary 120 for the ink to dry. The limited vertical movement of the printing disc rollers 31 is

controlled by an electric solenoid unit 38 operating through a suitable linkage using as a pivot the spindle of a roller 125 39 A photo-electric cell indicated generally at 40 is mounted at a position adjacent to the travelling web of material, preferably opposite a roller 41 over which the web passes prior to its entry into the printing section of the moni 130 784,996 toring unit The photo-electric cell is responsive to marlkings on the material produced by the pilot unit hereinbefore described, and actuates the printing unit The rollers 29, 30 and 31 are driven by a suitable gear train 42, and roller 30 driven by means of a chain and sprocket 43, 44 from a suitable prime mover in the sheeting machine itself These rollers are preferably driven from a prime mover, the speed of which relates to and is variable with the speed of travel of the web in order that the speed of the rollers may be synchronous with the speed of travel of the web. In Figure 7 the monitoring unit, shown generally at 45, is shown mounted on a Inown cross cut sheeting machine A reel 46 of coated material is shown mounted on a stand 48, the web of material 32 being shown passing through the monitoring unit 45 in two alternate ways-in one way (shown by arrows 49) the web passes over rollers 50, 41 and 39 to the printing unit of the monitoring device 45, and in the other the web 32 passes (as shown by arrows 51) direct to the printing unit It will be seen that the web in its path indicated by arrows 49 is guided past the photo-electric cell 40 arranged to initiate operation of the monitoring device 45 If it is not desired to make use of the photo-electric cell 40 the material would be conveyed along the path indicated by arrows 51, thereby by-passing the photoelectric cell. If for example the pilot unit described above was not used and the defective portions in the web were indicated merely by tabs placed by the operator in the reel of treated material, the path indicated by arrows 51 would preferably be used and the printing unit brought into operation by an operator on seeing the tabs in the reel. A control panel 52 is mounted on the stand 48 and incorporates two counting devices 53 and 54 which are arranged to record the number of sheets cut from the web of material. These counting devices 53 and 54 are actuated by a contactor unit 55 which is mounted on the main cutting beam 56 of the machine. The counting device 53 is arranged to count only the number of sheets without defective portions, whereas the counting device 54 counts only those sheets which have defective portions Normally when the sheeting machine is operating the counting device 53 will be recording As soon as the monitoring device is brought into action (either by the photo-electric cell or manually) to mark defective portions of the material, the counting device 53 is stopped and the counting device 54

is brought into action Thus if, for example, a stack of 100 sheets is required, the counting device 53 is set to count 100 sheets Therefore, if several more than 100 sheets are in actual fact cut from the web because of the arrangement whereby the device 53 is not in operation when defective sheets are being cut, in the resultant stack of sheets there will only be 100 sheets without defective portions The control panel 52 may also incorporate adjustable timelag switches (not shown) to compensate for the distance between the photo-electric cell and 70 the printing position which will vary according to the speed of opelration of the sheeting machine. Thus a final stack of sheets will be produced at the delivery end of the sheeting 75 machine, this stack containing the required number of sheets without defective portions and also a number of sheets with defective portions (these sheets having markings applied by the monitoring unit) 80 The stack of sheets is then removed to a guillotine where the edges are trimmed and then the sheets subsequently sub-divided. Inspection of the edges of the prepared sheets or the surfaces adjacent thereto will clearly 85 sho;v those which have been marled by the mcnioring unit These sheets are removed and stacks containing the required number ot sheets are left. The stand 48 is shown with a second reel 90 4.7 of coated paper mounted thereon which would be used after reel 46 according to known practice The alternate paths 49 and 51 of the web may be used with either reel 46 or reel 47 95 The invention is also applicable to roll cutting machines used for the conversion of a large parent reel of paper in web form into a number of smaller rolls of predetermined length, e g semi-automatic machines which 100 form rolls without the use of cores or centres. Such a machine incorporating a monitoring device is shown diagrammatically in Figure 8. A web of coated material 57 reeled coated side outside is drawn off from the top or 105 bottom (depending on whether the final rolls are required to be rolled coated side inside or outside respectively) of a reel of the material 58 by passage through a complex of rollers 59 and thence to a magazine shown generally at 110 where an appropriate length of the material is accumulated, the web then passes over a roller 61 through a monitoring device 62 (described later in detail) over a series of rollers 63, 64, 65 and 66 and thence between two 115 contacting rollers 67 and 68, the nip 69 of which draws the web past a cutting device 70 and finally to a complex of rollers 71, 72, 73 and 74 lwhere it is rolled (without a core) into a roll of predetermined length 120 The monitoring device 62 consists of three rollers 75, 76 and 77 of uniform diameter, the web of material 57 being threaded

through these rollers as indicated Two paths are show N in the figure, the choice of path being 125 governed by whether the vweb is drawn from the bottom of the reel 58 or the top of the reel. The draw-off position of the web from the reel is in turn governed by whether the reel is wound coated side outside or inside and 130 784,996 whether the final rolls of predetermined length are required to be rolled coated side inside or outside A photo-electric cell 78 is located adjacent to the roller 75 and, adjacent to the roller 76, but on the opposite side of the vertical plane of rollers 75, 76 and 77 there is mounted a small aniline type printing unit 79 It may also be desirable to mount an additional photoelectric cell 80 and a further aniline printing unit 81 The appropriate photo-electric cell and printing unit are used dependent upon the manner in which the web of material is threaded through the monitoring unit. The mode of operation of the monitoring unit 62 is similar to that previously described with reference to Figures 5, 6 and 7 i e the Dhoto-electric cell reacts to markings made on the web of material by a pilot unit and causes the aniline printing unit to be brought into operation and mark the defective sections of the web of material with a continuous band. There are also provided in the apparatus means (not shown) for recording the yardage of material passing through the monitoring unit Preferably two such means are provided, one being effective to record the yardage of material without defective sections, whereas the other records the yardage of the material having defective sections In addition, means may be provided for recording the number of rolls produced from material with and without defective sections. In some instances, e g when the roll cutting machine is converting material from a parent reel wound with the coated, processed or treated surface inside, and if no second photoelectric cell 80 and printing unit 81 is provided the photo-electric cell 78 would be mounted adjacent to the roller 76 and the aniline printing unit 79 mounted adjacent to the roller 77, but on the opposite side of the vertical plane of the rollers 75, 76 and 77. In operation, the photo-electric cell responds to markings made on the material by a pilot unit and a warning light becomes visible to the operator. Immediately upon reaction of the photoe'ectric cell to the pilot unit markings, the production of predetermined length rolls ceases at a point immediately in advance of the defective section with simultaneous stoppage of the machine The roll being produced is ejected by the operator, the machine re-started and suitably marked rolls produced until the whole defective section has passed through the monitoring unit, when the machine is again automatically stopped

The final roll of defective material is then ejected and the machine restarted, further rolls of predetermined length being produced until the next defective section occurs. Although these embodiments have been described with reference to paper coated with a light sensitive composition it is to be understood that the invention is by no means so limited.

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* GB784997 (A)

Description: GB784997 (A) ? 1957-10-23

Improvements in or relating to the stretching and forming of metal sheet orslab

Description of GB784997 (A)

PATENT SPECIFICATION Inventor: WILLIAM STEIPHEN HOLLIS 784,997 Date of filing Complete Specification: Oct 31, 1955. Application Date: Nov 3, 1954. No 31837/54. Complete Specification Published: Oct23, 1957. Index at acceptance:-Class 83 ( 4), E 1 (G: HI: JX), E 4 (A: F), E 7 (A: F), E 8 (C: E), E 10 (A 3: A 9: D 3: K). International Classification:-B 23 k. CO'MPLETE SPEGIFICATION Improvements in or relating to the Stretching and Forming of Metal Sheet or Slab We, NATIONAL RESEARCH DEVELOPMENT CORPORATION, a British Corporation established by Statute, of 1, Tilney Street, London, W.1, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it

is to be performed, to be particularly described in and by the following statement:- This invention relates to the stretching and forming of components from aluminium alloy and other metal stock having similar working characteristics, the said stock being in the form of sheet or slabs with a cross-sectional area varying along the length thereof The stock may consist of sheets or slabs of uniform width throughout the length thereof, for example, rectangular sheets, but tapering in thickness, or of sheets or slabs tapering in width but of uniform thickness, Or again the stock may taper in both width and thickness. Moreover, the stock may consist of sheets or slabs with plain surfaces or may have ribs and like projecting features on one or both surfaces. According to the present invention, a component is made by stretching and forming from aluminium and other metal stock having similar working characteristics, which is in the form of a sheet or slab of a cross-sectional area which varies progressively along a given dimension, and which stock is held at that end of said dimension which is of the larger crosssection and stretch is applied therefrom along progressively decreasing lengths of said dimension These progressively decreasing lengths are determined by forming the stock, independently of the stretching, by clamping it by operating forming means progressively along the given dimension towards the end from which stretch is effected, in order to obtain substantially uniform extenmion of the stock along this dimension. The part of the metal stock which is of the lPrice 3 s 6 d l smaller cross-sectional area and is situated at one end of the dimension along which stretching is to take place may be held in a clamp and the other part of the metal stock which is of the larger cross-sectional area at the other end of the said dimension may be connected to means between which and said clamp stretching is to be effected, whereby said smaller cross-sectional area part of the metal stock may be stretched when the aforementioned forming means which progressively clamps the metal is out of clamping engagement with the latter. A machine for carrying the invention into effect may comprise a pair,of clamps between which relative movement takes place to stretch the metal stock, one of which clamps holds the metal stock at one end, of the dimension to be stretched The second clamp clamps the metal stock progressively along the said dimension and includes a body having a surface conforming to the contour required for the finished component and constituting a former block, and a second block having a complementary surface, although not necessarily a mating one, which second block co-operates, either directly or indirectly, with the former block, in order that the metal stock shall be shaped on the contoured surface of the former block during the clamping action of

said second clamp 'Preferably a third clamp is provided for holding the metal at the opposite end of the dimension to be stretched to that which is held by the first clamp, so that one stretch can be effected directly between said first 'and third clamps without the second clamp being in operation, this having the advantage that in the case of a piece of metal stock requiring to be stretched practically from end to end this can be effected with little or no waste. If desired, instead of the second block directly shaping the metal upon the former block, 2 784,997 suitable means may be interposed between the second block and the metal upon the former block for doing this, such means for example comprising one or more jacks, in which latter case the second block would constitute a thrust block to take the thrust of said jacks during the shaping of the metal and to enable said jacks to maintain said metal firmly clamped during stretching The jacks may be hydraulically operated and connected to a source of fluid pressure through flexible hoses. The jacks may be linked together to form an articulated clamping device which may be constrained to form any determined sinuous geometry as required by the former and holder blocks at the section at which the clamping device is placed This articulated structure also assists the jacks to adjust themselves to the varying geometry of the former and second blocks as the said jacks are moved lengthwise along the stock Details of the jacks are describedl hereinafter. This arrangement may be used in the following manner: The stock is arranged between the former and second blocks with the first clamp connected to the end of the stock having the maximum cross-sectional area and the other end to the third clamp and, while the second dclamp is out of clamping engagement with the metal, a tensile stress is applied by causing relative movement between said first and third clamps, this tensile stress amounting to about 2 per cent above the elastic limit of the metal at the smaller cross-sectional end The stock is then formed upon and clamped to the former block Thereupon the stretching tension is increased to create the required tensile stress in the slightly stronger section of the material in front of the section clamped by the combined forming and clamping device. The stretching tension is then eased at least to its starting magnitude and the clamping device shifted to clamp and shape the stock at the section which has just been stressed above the elastic limit The steps of the process are then repeated until the stock has been stretched and formed over its entire length. Instead of employing a single means for phaping and clamping the material and inching this means along the material a number of such means may be employed, one for each section of the stock which is successively stressed In this case the stretching tension need never

be eased, the combined shaping and clamping means being operated to come into effect successively as the stretching tension is increased Safety means may be provided for interlocking the combined forming and clamping means with the tensioning means so that no stretching tension above that necessary to stretch the portion of the stock which is of the smallest cross-sectional area can be applied until the clamping pressure has been effect ively applied by said forming and clamping means. Furthetmore the pressure supplied to the clamping device may be arranged to pulsate so that a carrier containing the device can slide progressively along the stock, locating 70 and clamping the said stock in advance of the application of the tensile stress appropriate to the clamping position To this end the pulsations in the jacks and, tensioning means may correspond in frequency but not in phase, since 75 the clamping pressure must be effective throughout the building up of the tensile stress to stretch the sheet and its return to its minimum. In an alternative method of carrying out 80 the invention, the former and, second blocks may be arranged to move relatively to one another in the manner of the jaws of a press and may exert a clamping and forming pressure on the stock through the intermediary of 85 a series of spacing blocks arranged between said former and second block The spacing blocks may be in the form of pads or strips of tough, resilient material or in the form of metal blocks preferably associated with resi 90 lient or spring means As the forming process proceeds the spacing blocks are shifted step by step along the stock in the manner previously described in the case where the jacks are employed In this method also interlocking 95 may be employed, between the stretching means and clamping means. In still another method of carrying out the invention, which may be suitably employed for relatively 'light and narrow stock, the said 100 stock while under tension is shaped by complementary former blocks which perform as rollers For example, for forming an elongated transversely curved component from flat strip of tapering thickness, one former may consist 105 of an elongated block with a pressure surface which is concave in cross-section whilst 'the other block consists of a quadrantal member or roller the arcuate surface of circumference of which is convex in cross-section and is 110 capable of rolling within the concave pressure surface of the other block to generate the required form For forming transversely 'curved components the curvature of which varies progressively from one end to ithe other, blocks 115 may be used having pressure surfaces with correspondingly progressively varying shape This will permit the clamping and shaping roller blocks to operate progressively and

uninterruptedly as the longitudinal tension is in 120 creased, the point of anchorage for example moving progressively from the weaker end of the stock towards the stronger end. One form of the invention and a suitable way of carrying the same into effect 'will now 125 be described by way of example, with reference 'to the diagrammatic drawings accompanying the Provisional specification, in which: Figure 1 is a side view of a complete stretch 130 784,997 steel pistons 15 of Fig 3 are dispensed with and the rubber or like heads 19 of the jack are shaped at their ends within the cylinder to provide an effective seal when the operating pressure is applied. To enable the jacks to be shifted along the stock during the course of the stretch forming process, the series of jacks are arranged within a cage member 20 comprising a pair of parallel bars 21 extending crosswise between the blocks 2 and 5, one bar on either side of the series of jacks 9 The cage member 20 slides on two bars 22 extending longitudinally of the machine, one on either side of the former block 2. If the machine shown in Figs 1 and 2 is constructed as a press with the holder blocks movable relatively to the former blocks 2, the jacks 9 may be replaced by simple pads or spacing blocks and the fluid pressure supply lines previously referred to are thus eliminated'. forming arrangement, Figure 2 is a sectional view on the line II-II Figure I looking in the direction of the arrows. Figure 3 shows one form of construction of the jacks which may be used for clamping the stock and Figures 4 and 5 show alternative forms of the jacks. In Figure 1, the arrangement, comprises a rigid base member 1 on which is mounted a former block 2 A rigid member 3 supported by pillars or tie rods 4 carries a second block 5, at a distance above the former block 2. The stock '6 is clamped at its weaker end to a ram 7 and at its stronger end to another ram 8. The stock 6, initially in the form of a flat sheet, is applied to the former block 2 and the ram 8 is operated to apply a tensile stress to the stock of such magnitude that the material at the weaker end, that is, the end nearest the ram 7, is stressed to about 2 per cent above the elastic limit of the material Thereafter a series of jacks 9 is inserted beneath the second block 5 at the end nearest the ram 7 and the stretch forming process is carried out as hereinbefore described. The jacks are more clearly shown in Figures 2 and 3 Each of the jacks forms part of a series of double acting hydraulic jacks; 9, the cylindrical bodies 10 (Fig, 3) of which are formed with wings 11, with a wing on one jack pivotally connected as at 12 to a wing of an

adjacent jack to form an articulated structure The jacks are hydraulically operated, each jack having an individual supply pipe (not shown) communicating with a common source of fluid pressure, each supply pipe being connected to a part 13 at the middle of each cylinder 10 Various forms of jacks may be provided In the form shown in Figure 3, the said cylinderical body 10 is closed at each end by a head 14 of tough, resilient material such as rubber, the heads 14 having piston-like extensions extending into the cylinder 10 and engaging steel piston 15 which receive the pressure of the hydraulic medium The resilience of the rubber heads 14 permits the jacks to conform to the contour of the blocks 2 and 5 and enables the stock to be formed closely in contact with the former block 5 The heads 14 may be moulded with channels 16 to accommodate ribs on the stock when ribbed stock is being stretched. In the construction of jack shown in Fig. 4, pistons 17 within the cylinder 10 are connected by spring loaded, ball jointed? connections to gripper members 18 of steel, aluminium or other suitable metal, The faces of the members 18 may be milled to improve their grip on the stock when the jacks are acting as clamping members. The construction of jack shown in Fig 5 differs from that shown in Fig 3 in that the Automatic means may be provided to vary and control within close tolerance the magnitude of longitudinal stressing, this magnitude 90 being determined by the rate of taper of the sheet in thickness, or in width in the case where the sheet material being formed is other than rectangular Since strain is expressed as elongated per unit length, and is independent of 95 cross-sectional area, an extensometer or extensometers or strain gauges, positioned across the section might alternatively be attached to suitable means to measure the required elongation to stress stabilise or form the sheet or 100 slab at each position as the loads are applied incrementally, and thereby control the tensile loads applied, and the loading sequence of the holding jacks In the case of a rectangular sheet, pressure variation can be determined 105 either by feedback from measurement at the point where the jacks are located, or by the distance the jacks have travelled, In the case of non-rectangular sheet tapering in thickness, both forms of measurement may be em 110 ployed Orthodox means such as oil leak-off or opposed pressure on the back of the tensioning ram may provide the means, of pressure variation Alternatively control can be effected by a cam either in the form of a figure 115 of revolution or of lineal form, with a cam profile determined by the tension on the sheet and the cross-sectional area of the sheet at the part being stretched The cam or template may, for example, co-operate with andf 120 move, through a roller or other

body, a lever which controls the stressing means, the relative movement between said cam or template and roller or other body being in timed relationshlip with the progressive clamping and/or 125 stressing of the metal stock. The pressure of the jacks or the pads or strips of tough resilient material or the metal blocks, as well as clamping the metal sheet or stock during stretching will also serve to 130 784,997 form or shape the sheet on the former block so that the sheet is shaped or formed step-bystep as the jacks or other clamping means are advanced along the former block As the stretching tension is increased, due to the increasing cross-sectiona I area of the part of the sheet being stretched, it may also be necessary to increase the pressure of the clamping devices It is, however, desirable, especially in the case of lighter gauge tapered sheet, to employ the minimum tension necessary in order to prevent distortion of the formed part of the sheet, especially, for example, when a considerable radius is imposed upon the sheet.

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