Robert D Mcmichael

US Patent:

47212853, Jan 26, 1988

Filed:

Sep 23, 1986

Appl. No.:

6/910608

Inventors:

Robert G. McMichael - Silver Spring MD

International Classification:

B01D 1704
B65H 2000

US Classification:

254333

Abstract:

A cable drive system for driving a cable includes a rotatable inflatable member. Sets of guide rollers are positioned about the periphery of the inflatable member, and each of the sets of rollers includes at least two rollers for guiding the cable to maintain the cable substantially in contact with the inflatable member, and to cause the cable to be wound helically about the inflatable member. A fluid supply is used to inflate or deflate the inflatable member to vary the normal force applied to the cable. The inflatable member may be similar to an automobile tire and supported on a wheel through which the inflatable member is rotatably driven. During deployment or retrieval of the cable, the frictional drive force on the cable can be controllably varied by inflating or deflating the inflatable member to vary the normal force applied to the cable. Since the frictional drive force is equal to the product of the normal force and the coefficient of friction, the normal force can be varied to take into account desired changes in the frictional drive force or changes in the coefficient of friction.