Patent ID: 9267551
Filing Date: 2016-02-23
CPC Classification: F16D

Claim Text:
1. A safety coupling comprising a safety mechanism and a safety arrangement related to each other, the safety coupling comprising; a coupling unit adapted to, upon rotary movement, permit the transmission of torque between two coaxially oriented coupling members comprising a first, driving, inner coupling member and a second, driven, outer coupling member, with a shaped friction surface located between the inner coupling member and the outer coupling member, wherein the inner coupling member comprises a cavity adjacent to the friction surface which, upon applied pressure, is adapted to expand in the direction of the friction surface; wherein the coupling unit is actuatable between a retaining position wherein the cavity is in an expanded position, and a releasing position wherein the cavity is in a non-expanded position; wherein the safety arrangement is adapted to, when a preselected torque and a relative motion caused by the preselected torque between the first coupling member and the second coupling member are exceeded, be triggered by the safety mechanism to evacuate a pressure from the cavity to bring the coupling unit from the retaining position to the releasing position; wherein the safety arrangement is adapted to instantaneously bring the coupling unit to the releasing position, wherein the safety mechanism is adapted to allow a limited relative movement between the first coupling member and the second coupling member, corresponding to a selected maximum arcuate distance between an initial active position and a final inactive position of the safety mechanism, without triggering the safety arrangement, and wherein means allocated to the safety mechanism are adapted to, upon a final operating cycle of the safety coupling, return and/or displace the safety mechanism in the direction of the initial active position, in order to provide again from the initial active position the limited relative movement between the first coupling member and the second coupling member during a subsequent operating cycle; wherein the limited relative movement between the first and second coupling members is below a few revolutions; and wherein the cavity interacts with a valve assembly adapted to be opened instantaneously by a cutting operation, activated by the rotation of an adjacent first disc.