- Hoberman sphere
A Hoberman sphere is a structure that resembles a
geodesic dome , but is capable of folding down to a fraction of its normal size by thescissor -like action of its joints. Colorful plastic versions have become popular as a child's toy: several toy sizes exist, with the original design capable of expanding from 15 cm (6 inches) in diameter to 76 cm (30 inches).A Hoberman sphere is not a true sphere, but a
polyhedron known as anicosidodecahedron . The Hoberman sphere can be unfolded by allowing certain members to spread apart. This can be accomplished by feeding out a string or cable in the larger models. The operation of each joint is linked to all the others in a manner conceptually similar to the extension arm on a wall-mounted shaving mirror.The largest existing Hoberman sphere is in the atrium of
Liberty Science Center inJersey City, New Jersey . Fully expanded, it is 5.5 m (18 feet) in diameter. The motorized sphere weighs 318 kg (700 pounds), is constructed ofstainless steel andaluminium , and continually oscillates between its compact and expanded states.Its inventor,
Chuck Hoberman , holds several patents onfolding techniques, many of which resemble the designs ofBuckminster Fuller but for the folding aspect.External links
* [http://www.hoberman.com Hoberman.com ::: Welcome to the World of Magical Transformation]
* [http://www.google.com/patents?id=eyEgAAAAEBAJ&dq=hoberman Google Patents - Patent #5024301]
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