Linear motion cable drive - has drive cable wrapped helically on driven cable and rotated to cancel effects of helical wrapping

摘要

The linear cable drive comprises a series of drive assemblies cooperating to drive a cable. Each assembly includes a drive cable helically engaged around the periphery of the driven cable. The cable is driven in the helical path and also rotated with its drive, about the axis of the driven cable at such a rate and in a direction so as to unwrap the forward end of the drive cable. This negates any rotational forces imparted to the driven cable by the helical path. A length of driven cable is allowed to pass which has a peripheral dimension that varies from the base peripheral dimension without imparting rotational forces to it.