A brief demonstration and small explanation aboutthe Levitron levitating top device.

LevitronFrom Wikipedia, the free encyclopedia

Not to be confused with Leviton, an electrical manufacturing company.

Levitron is a brand of levitating toys and gifts in science and educational markets marketed byCreative Gifts Inc. and Fascination Toys & Gifts.[1] The Levitron top device is a commercial toy thatdisplays the phenomenon known as spin-stabilized magnetic levitation. This method, with movingpermanent magnets, is quite distinct from other versions which use changing electromagnetic fields,levitating various items such as a rotating world globe, model space shuttle or VW Beetle, and pictureframe.[2] 750,000 units were sold from 1994 through 1999.[1]

Contents

1 The device2 Company history

2.1 Invention and patents2.2 Trademark litigation

3 References4 External links

The device

The toy is essentially a permanent magnetic top and base plate, ring or alternate geometric configuration. Functional parameters, such as the top rotationrate or top weighting, are stringent. Employing principles of the magnetic field and gyroscopic stabilization, the Levitron induces levitation in its topthrough a series of interactive steps. The levitated top's stabilizing rotation undergoes natural, gradual slowing, so that the levitation phenomenon failswithin four minutes unless external power is supplied to sustain rotation.

To levitate the top, a plastic plate is placed on top of the magnetic base, and the top is spun on the plate at between 25-50 rotations per second (1500-3000rpm). If too slow, the top falls over and slides off sideways; if too fast it does not orient itself to follow magnetic flux as it moves, and slides off. Since itcan be difficult to spin the top fast enough by hand, Creative Gifts makes a battery-powered, hand held device to spin the top with an electric motor. Next,the plate is lifted by hand until, if conditions are right, the top rises above it to an equilibrium point. The top must also be weighted with washers of varioussizes supplied in the kit. If too heavy it will not rise above the plate; if too light it flies off.[3]

After a few minutes, the top falls when air friction slows it below the critical speed. Air temperature, air currents, ground vibration, and power sourceinterruptions also alter the delicate equilibrium necessary to keep the top stable. More expensive laboratory versions can sustain a levitating top indefinitelyby sustaining the top rotation actively compensating for aberrations in rotation. The makers of the Levitron have developed a "Perpetuator", which sitsunder the Levitron and sends out an additional magnetic pulse. The additional force nudges the spinning top enough to maintain a constant speed. With aconstant speed, and with the Levitron perfectly level, the Levitron top can spin for longer periods of time.

Company history

Invention and patents

The device that was later named Levitron was originally invented (c 1976) and patented (1983) by Vermont inventor Roy Harrigan. A Seattle entrepreneur,Bill Hones, came across the patent in the process of trying to develop a levitating magnet. Hones borrowed the prototype from Harrigan, analyzed itsphysics with help of his father, who worked at Los Alamos National Laboratory, then filed an "improvement patent" of his own.[4][5]

Trademark litigation

In the 1990s, Michael and Karen Sherlock formed the company they named "UFO" in New Mexico to market the Levitron under an oral agreement inpartnership with Hones' company, Creative Gifts, Inc.[5] Efforts to formalize the agreement in writing fell apart and grew acrimonious[1] after UFO'sprincipals learned about the device's earlier invention by Harrigan, and redesigned their website[6] to incorporate the exposé-style article "THE HIDDENHISTORY OF THE LEVITRON!", which accused Hones of stealing the invention from Harrigan.[5] Creative Gifts, in turn, filed a trademark infringementsuit in United States District Court of New Mexico against UFO and its owners. At trial and on appeal to the Tenth Circuit[7] Creative Gifts' trademarkclaims were upheld, and all of UFO's counterclaims were rejected after UFO, which had been representing itself as a pro se defendant, was sanctioned bythe court for abuse of discovery. The appeals court, noting that UFO had submitted a one-page opening brief with no citations to the record or discussion ofthe relevant law, commented in its ruling, "they have shot themselves in the foot."

References

^ a b c Martin B. Paskind (2001-02-26). "Take care not to shoot yourself in the foot." (http://www.accessmylibrary.com/coms2/summary_0286-2604340_ITM) .Albuquerque Journal. http://www.accessmylibrary.com/coms2/summary_0286-2604340_ITM.

1.

^ Elizabeth Corcoran (2007-11-27). "Toys Your Techie Friends Will Love" (http://www.forbes.com/2007/11/29/toys-techie-gadgets-tech-holidaytech07-cx_ec_1129toys.html) . Forbes. http://www.forbes.com/2007/11/29/toys-techie-gadgets-tech-holidaytech07-cx_ec_1129toys.html.

2.

^ Michael V. Berry. "Levitron Physics: Frequently Asked Questions About the Levitron" (http://www.lauralee.com/physics.htm) . Conversation for Exploration.http://www.lauralee.com/physics.htm.

3.

^ Rod Driver (1999-09-22). "An amazing invention, and a patent failure (Part 1 of 2)" (http://www.roddriver.com/science_990922.html) . The Providence Journal.Archived from the original (http://www.projo.com/report/pjb/stories/02602561.htm) on 2001-03-06. http://www.roddriver.com/science_990922.html.

4.

Levitron - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Levitron

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^ a b c Rod Driver (1999-09-23). "The patent that failed its invention (Part 2 of 2)" (http://www.roddriver.com/science_990923.html) . The Providence Journal.Archived from the original (http://www.projo.com/report/pjb/stories/02606761.htm) on 2001-03-06. http://www.roddriver.com/science_990923.html.

5.

^ "Levitron Central" (http://amasci.com/maglev/lev/index.html) . http://amasci.com/maglev/lev/index.html.6.^ Creative Gifts, Inc. v. UFO, 235 F.3d 540 (10th Cir. 2000)(New Mexico)7.

External links

Levitron home page (http://www.levitron.com/)Spin stabilized magnetic levitation (http://www.physics.ucla.edu/marty/levitron/)Online simulation of the Levitron (Java applet) (http://www.koepken.de/levitron/)

Retrieved from "http://en.wikipedia.org/w/index.php?title=Levitron&oldid=533589762"Categories: Trademarks Magnetic levitation Magnetic devices Educational toys Tops

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Levitron - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Levitron

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