Abstract: The present invention comprises a safety mechanism (2, 3, 3a, 3b), which is related to and/or integrally formed with a safety coupling (1), wherein the safety coupling, with a related safety mechanism (3a) actuatable toward and into an initial active retaining position or toward and into a final inactive releasing position, is adapted, upon rotary motion, to allow for the transmission of torque between a first, driving coupling member (10) and a second, driven coupling member (20) and wherein said actuatable safety mechanism is adapted to be actuatable in a displacement from an initial active position, via a number of intermediate positions, to a final inactive position.

Abstract: A torque transmitting cardan shaft including within the shaft an adapted intermediate member or shaft, which has a first end section, that is intended for a rotationally rigid co-action with a first universal joint yoke and a second end section, opposite the first end section, intended for a rotationally rigid co-action with a second universal joint yoke. The intermediate member or shaft and its end section is configured as and comprises two parts or subsections, which are mutually joined via a safety coupling arrangement, by means of which a free coupling of the subsections from one other can be ensured immediately after the torque, between the subsections, exceeds a predetermined value, determined by the construction of the safety coupling arrangement. An end section and its universal joint yoke includes an axially orientated cylindrical groove or recess, which has a center axis that is co-ordinated with or aligned with a rotational axis of the first end section and its co-ordinated universal joint yoke.

Abstract: A safety coupling apparatus which includes first and second annular coupling parts for attachment to first and second coaxial rotatable shafts. The second coupling part defines an axial chamber which has an open end facing the first coupling part, and a radially-extending recess between a collar and a flange, both extending and located radially outwardly of the axial chamber, wherein the flange is spaced from the collar. An expandable hollow body of the first coupling part axially extends through the open end and into the axial chamber. A cavity subdivides the hollow body into inner and outer cylindrical sections and can (1) be filled with, or (2) emptied of pressurized fluid to expand or contract the inner and outer sections relative to one another and cause or prevent external surfaces thereof to contact adjacent surfaces of the axial chamber and thereby prevent or enable relative rotation of the first and second coupling parts.