Abstract: An anti back-drive coupling (5) comprises an input (20) driveable about an axis A in a clockwise and anticlockwise direction in torque transmitting communication, via a mechanism, with an output (40) driveable about the axis by the input in either of the rotational directions, the mechanism including: a tube (29), driveable by the input, carrying two cages (21) and (23) spaced along the axis A, each cage housing rollers (26) and (28) respectively; an output member 48 for driving the output (40), including two flattened formations (42) and (44) adjacent each cage in use, for engagement with the rollers (26) and (28) respectively; and a back-torque reaction freewheels (30) and (32) engageable with the rollers, for reacting back-torque transmitted through said output member (48) and into the rollers.

Abstract: An anti back-drive coupling (5) comprises an input (20) driveable about an axis A in a clockwise and anticlock-wise direction in torque transmitting communication, via a mechanism, with an output (40) driveable about the axis by the input in either of the rotational directions, the mechanism including: a tube (29), driveable by the input, carrying two cages (21) and (23) spaced along the axis A, each cage housing rollers (26) and (28) respectively; an output member 48 for driving the output (40), including two flattened formations (42) and (44) adjacent each cage in use, for engagement with the rollers (26) and (28) respectively; and a back-torque reaction freewheels (30) and (32) engageable with the rollers, for reacting back-torque transmitted through said output member (48) and into the rollers.