Editing Levitron (section)

===Invention and patents===
The first spin-stabilized permanent magnet levitation device was invented (c 1976) and patented (1983) by inventor Roy Harrigan, of Vermont. In the mid-1990s, Seattle entrepreneur Bill Hones, who was himself exploring the possibility of permanent magnet levitation, discovered Harrigan's patent. Hones subsequently contacted Harrigan and later met with him. Upon Hones' request, Harrigan permitted him to borrow his prototype with the understanding that they were entering into a business arrangement. Hones, with the help of his father, a Physicist and employee at [[Los Alamos National Laboratory]], analyzed the physics of the prototype, and then filed for an "improvement patent".<ref name=patent0>{{cite news|url=http://www.projo.com/report/pjb/stories/02602561.htm|publisher=[[The Providence Journal]]|date=1999-09-22|title=An amazing invention, and a patent failure (Part 1 of 2)|author=Rod Driver|author-link=Rod Driver}}{{dead link|date=May 2020|bot=medic}}{{cbignore|bot=medic}} [http://www.roddriver.com/science_990922.html Alt URL]</ref><ref name=patent>{{cite news|url=http://www.projo.com/report/pjb/stories/02606761.htm|publisher=The Providence Journal|date=1999-09-23|title=The patent that failed its invention (Part 2 of 2)|author=Rod Driver|author-link=Rod Driver}}{{dead link|date=May 2020|bot=medic}}{{cbignore|bot=medic}} [http://www.roddriver.com/science_990923.html Alt URL]</ref> In 1984, independent of Roy Harrigan, inventor Joseph Chieffo, of Pennsylvania, also discovered spin-stabilized magnetic levitation. Chieffo then developed his own [http://www.amasci.com/maglev/lev/exhibit2.gif spin-stabilized magnetic levitation device] and attempted to obtain a patent thereon. Employing an attorney to conduct a U.S. Patent and Trademark records search, Chieffo was informed of the existence of the Harrigan patent; he thus concluded his efforts to secure a patent. In a final assessment, Chieffo's attorney noted that his device, although apparently unpatentable, could be marketed without infringing upon the Harrigan patent. In 1988, Chieffo marketed his device in kit form. Contrasting with the dished supporting magnet of the Harrigan invention, the base magnet of this latter device was rectangular and planar of upper surface, not unlike the base magnet of Hones' later-patented device, the now-popular Physics toy known as the Levitron.

In 2012<ref>{{cite journal | last=Michaelis | first=Max M. | title=Inclined Levitron experiments | journal=American Journal of Physics | publisher=American Association of Physics Teachers (AAPT) | volume=80 | issue=11 | year=2012 | issn=0002-9505 | doi=10.1119/1.4742756 | pages=949–954| bibcode=2012AmJPh..80..949M }}</ref> and 2014,<ref name="Hozax">{{cite journal | last=Michaelis | first=Max M | title=Horizontal axis Levitron—a physics demonstration | journal=Physics Education | publisher=IOP Publishing | volume=49 | issue=1 | date=2013-12-18 | issn=0031-9120 | doi=10.1088/0031-9120/49/1/67 | pages=67–74| s2cid=121645252 }}</ref> Levitrons were operated at an angle of 45° as well as with their spin axis horizontal. This inclined and horizontal operation was obtained with the help of additional magnetic "V"s. The horizontal Levitron is particularly stable, which gives it educational potential.<ref name="Hozax" />