Abstract: A clutch mechanism for use in rotationally operable devices, for example a window raising and lowering system of a vehicle, allows rotation in either direction when operated properly by means of a specially provided shaft, but prevents rotation if unauthorized attempts are made, for example to lower or raise the window. The shaft is connected to two or more lugs which on rotation co-act with respective wedge elements located in respective recesses at the periphery of a rotatable disc so that drive is transferred from the lugs to rotate the disc. At least one lug and associated wedge element is mounted in the same sequence in each circumferential direction around the disc so that the disc can be rotated in either direction.