Patent ID: 7997158

Claim:
A rotary to linear transmission comprising: a body member first and second drive capstans rotatable in unison about a common axis relative to said body member, said first capstan having smaller diameter than said second capstan; first and second idler pulley means rotatable about axes parallel to said capstan axis, the capstans being interposed between the first and second idler pulley means; a linkage member supporting said first and second idler pulleys for rotation on their axes and retaining said axes at a particular relative distance, said linkage member being engaged relative to said body member for non-arcuate and substantially linear motion; first pulley line means windingly engaged about the first capstan, the first idler pulley, and the second capstan; second pulley line means windingly engaged about the first capstan and the second idler pulley means in the same direction as the first pulley line means; and third pulley line means windingly engaged about the second capstan and the second idler pulley means in the same direction as the first and second pulley line means; such that rotation of said capstans in unison is operable to cause differential winding of said first, second and third pulley line means in cooperation and thereby urging of said idler pulleys and said linkage member in said substantially linear engagement of said linkage member relative to said capstans.