Clutch and transmission mechanism

A mechanism for receiving an elongated object, such as a key blank, that is to be machined to a desired shape at a plurality of successive positions in an axial direction of said object, comprising a frame, a holder for carrying the object in a predetermined orientation with respect to the frame, and a transfer device for moving the holder with respect to the frame in the axial direction of the object when carried in said predetermined orientation, said transfer device comprising:

• a support which is mounted to the frame so as to be movable with respect thereto in the axial direction of the object when carried in said predetermined orientation;
• a shaft mounted in the support to rotate about an axis of rotation aligned with the direction of movement of the support but being fixed against axial movement relative to the support, the shaft being connected to the holder for transmitting rotational movement thereto;
• a first clutch member which is stationary relative to the support with respect to the axial direction of the shaft;
• a second clutch member which is stationary relative to the frame with respect to the axial direction of the shaft and is engageable by the first clutch member to lock the shaft and the support against axial movement relative to the frame;
• and
• a feeder member which is connected to the rotatable shaft and which co-operates with the first clutch member so that said first clutch member is disengaged from the second clutch member during only a small range of angular positions of the rotatable shaft, thereby permitting axial movement of the rotatable shaft and the support during said small range of angular positions, and is engaged with the second clutch member, thereby preventing axial movement of the rotatable shaft and the support, at angular positions of the shaft outside said small range of angular positions, said feeder member engaging the second clutch member during only said small range of angular positions of the rotatable shaft, whereby co-operating guiding surfaces of the feeder member and of the second clutch member transmit an axial movement to the rotatable shaft and to the support during rotation of the shaft through said small range of angular positions.