Abstract: A power transmission apparatus transmits power from a rotatable cam to an output mechanism. A variable length lever, comprised of first and second lever sections, is pivoted to a lever support by a fulcrum. The lever sections telescopingly or otherwise interconnected to allow the over-all length of the lever to vary. In addition, the first lever section includes a cam following end portion which is drivenly coupled to the cam. Also, the second lever section has an output end portion which is pivoted to the output mechanism. The lever oscillates when the cam following end portion is driven by the cam and drives the output mechanism. A drive adjustment device moves the fulcrum relative to the cam following and output end portions of the first and second lever sections. This varies the throw of the output end portion with the zero drive being possible.

Abstract: A power transmission apparatus includes a housing to which input and output shafts are journalled. The input shaft is rotated by a motor or prime mover to thereby drive a cardioidal-shaped cam. The cam reciprocates a drive rod which has a first end slidably and pivotally connected to one end portion of a plural-section lever. The lever is pivoted to a lever supporting structure for oscillating movement, in response to reciprocations of the drive rod. The lever pivots about a fulcrum pivot axis which is fixed relative to the lever and positioned intermediate the ends of the lever. A first end portion of an output rod is slidably and pivotally connected to the other end portion of the lever. A drive speed adjustment mechanism is provided for shifting the lever supporting structure, and thereby the lever, relative to the input and output loads.