Power transmission mechanism

Power transmission mechanism comprising:

• (a) a longitudinally extensible and retractable driving shaft having an outer end portion including a longitudinally outwardly tapering coupling head and an inner end portion;
• (b) a driven shaft having an inner end portion, an outer portion, and a universal joint connecting said outer end portion to said inner end portion;
• (c) said inner end portions of said shafts being arranged to be connected, one to a prime mover for rotation, and the other to an apparatus to be driven;
• (d) said outer end portion of said driven shaft comprising a longitudinally inwardly tapering coupling socket for interfitting reception of the tapered head of said first shaft;
• (e) yielding means urging said inner and outer end portions of the driven shaft toward axial alignment with each other;
• (f) and means for imparting extending and retracting movements to said driving shaft to move said head into and out of interfitting driving engagement with said socket,
• wherein said coupling head has a generally circular cross-sectional configuration and a sprocket element having a plurality of teeth is attached to the outer surface of the coupling head adjacent its widest end, and wherein said coupling socket has a generally circular cross-sectional configuration and at least one engagement finger extending from said coupling socket for reception between an adjacent pair of said teeth.