Rotary coupling

6 A rotary coupling as claimed in claim 1, wherein each coupling unit includes an opening and the driven part includes a pin element which is received in the said opening, the pin element, on application of a reverse torque to the rotary coupling, aiding movement of the coupling unit into wedging engagement with the braking surface of the fixed part.

A rotary coupling comprising a driving part and a driven part, for transmission of driving torque between them, a fixed part in which the driving and driven parts are each rotatable coaxially, and a set of coupling units carried by the driving part and seated in recesses in the driven part so as to be in torque-transmitting engagement therewith, each recess having a slot and each coupling unit being juxtaposed to an annular braking surface of the fixed part and having a skirt received in the slot to stabilise the coupling unit in a direction parallel to the rotational axis of the rotary coupling, each coupling unit being free to move, with respect to the driving and driven parts, into and out of engagement with the braking surface, and the arrangement being such that a driving torque, applied by the driving part to the coupling units, is transmitted by the latter to the driven part without engagement of the coupling units with the braking surface;

• but a reverse torque, applied by the driven part to the coupling units, progressively moves the coupling units into wedging engagement with the braking surface so as to progressively lock up the rotary coupling.

A rotary coupling comprising a driving part and a driven part, for transmission of driving torque between them, a fixed part in which the driving and driven parts are each rotatable coaxially, and a set of coupling units carried by the driving part and seated in recesses in the driven part so as to be in torque-transmitting engagement therewith, the coupling units being juxtaposed to an annular braking surface of the fixed part, each coupling unit being free to move, with respect to the driving and driven parts, into and out of engagement with the braking surface and including a wedging part, having a wedging surface, and a pivot element which projects from the wedging surface into contact with the braking surface of the fixed part, the arrangement being such that a driving torque, applied by the driving part to the coupling units, is transmitted by the latter to the driven part without engagement of the coupling units with the braking surface;

• but a reverse torque, applied by the driven part to the coupling units, pivots each wedging part about its respective pivot element so that the coupling units progressively move into wedging engagement with the braking surface to progressively lock up the rotary coupling.

A rotary coupling comprising a driving part and a driven part, for transmission of driving torque between them, a fixed part in which the driving and driven parts are each rotatable coaxially, and a set of coupling units carried by the driving part and seated in recesses in the driven part so as to be in torque-transmitting engagement therewith, the coupling units being juxtaposed to an annular braking surface of the fixed part and being free to move, with respect to the driving and driven parts, into and out of engagement with the braking surface, each coupling unit including an opening and the driven part including a corresponding pin element which is received in the said opening, the arrangement being such that a driving torque, applied by the driving part to the coupling units, is transmitted by the latter to the driven part without engagement of the coupling units with the braking surface;

• but a reverse torque, applied by the driven part to the coupling units, moves each coupling unit into wedging engagement with the braking surface, the wedging engagement being progressive due to the pin element aiding the movement of the coupling unit to progressively lock up the rotary coupling.