New or improved torque limiting clutch

Claim 1

A torque limiting clutch comprising opposed first and second members mounted for relative rotational and axial movement, a third member positioned between and mounted for rotational movement relative to the first and second members and for axial movement relative to at least one of the first and second members, the third member being provided with a torque transmitting element receiving aperture, a torque transmitting rolling element being positioned in the aperture in the third member, the first member comprising a driven member and being provided with a torque transmitting abutment for torque transmitting engagement with said torque transmitting element, another of said members comprising a driving member and being provided with a torque transmitting abutment for torque transmitting engagement with said torque transmitting element, resilient loading means to bias resiliently the first and second members towards one another and the arrangement being such that when the clutch is transmitting torque the torque transmitting element is engaged with a driving member abutment and a driven member abutment so as thereby to prevent relative rotation between the driving and driven members and so that, on the torque to be transmitted exceeding a predetermined value, the torque transmitting element dis-engages from the abutment of at least one of the driving and driven members to permit of the members rotating relative to one another and including a spacer element received in an opening in the third member and positioned between a first track axially located relative to one of the members and a second track axially located relative to another one of the members, a spacer element receiving means provided on at least one of the tracks and of such dimensions as to maintain the spacer element out of pressure contact with the tracks during torque transmittal so as to ensure the torque transmitting element is maintained in pressure contact with the driven and second members, and a torque transmitting element receiving means provided on one of said driven and second members, whereby on disengagement of the torque transmitting element from the torque transmitting abutment in the driven member the third member is caused to rotate relative to the driven member and hence cause circumferential movement of the spacer element out of the spacer element receiving means and subsequently to cause the torque transmitting element to be engaged and maintained within the torque transmitting element receiving means with the driven and second members spaced apart by the spacer elements, the torque transmitting element receiving means being of such dimensions that the torque transmitting element is maintained out of pressure engagement with the driven and second members and relative rotation between the driving and driven members is permitted when the torque transmitting element is engaged in the torque transmitting element receiving means, and wherein there are means operative only during re-setting of the clutch to move the torque transmitting element into engagement under pressure with the member of the first and second members which is unprovided with a torque transmitting element receiving means.