Variable power ratio device

Claim 2

A variable ratio drive device comprising, in combination: a. a shaft; b. means for rotatably supporting said shaft; c. a belt; and d. a pair of axially shiftable pulleys rotatably fixed to said shaft, said pulleys being of different diameter and coaxially positioned adjacent each other, with each pulley including wall elements defining grooves in said pulleys, one wall element that is disposed between said grooves including a cutout portion to cause said belt to be shifted from one pulley to said other pulley in response to an axial shifting and rotary movement of said pair of pulleys.

Claim 3

A variable ratio drive device as defined in claim 1 further characterized in that said device includes means for axially shifting said pulleys on said shaft.

Claim 4

A variable ratio drive device as defined in claim 2 further characterized in that said pulley shifting means includes a lever pivotally mounted between its opposite ends, with one end associated with said pair of pulleys in rotatable, non-axially movable relationship, with an opposite end of said lever including handle shifting means.

Claim 5

A variable ratio drive device as defined in claim 1 further characterized in that said shaft includes an axially elongated slot extending therethrough, and wherein said pair of pulleys include a pin extending through said slot to permit axial shifting movement of said pulleys relative to said shaft while rotatably fixing said pulleys to said shaft.

Claim 6

A variable ratio drive device as defined in claim 4 further characterized in that said shaft includes cushion means operatively associated with axial movement of said pin to absorb impact during axial shifting movement of said pulleys.

Claim 7

A variable ratio drive device as defined in claim 1 further characterized in that said device includes an idler pulley supported on said device to be aligned selectively with said pair of pulleys, including means for biasing said idler pulley to a belt tightening position.

Claim 8

A variable ratio drive device as defined in claim 6 further characterized in that said idler pulley includes stop means for limiting movement of said idler pulley away from a belt tightening position.

Claim 9

A variable ratio drive device as defined in claim 7 further characterized in that said limit stop means includes impact absoring means for absorbing impact of movement of said idler pulley away from said belt tightening position.

Claim 10

A variable ratio drive device as defined in claim 7 further characteriZed in that said idler pulley is supported for pivotal movement between a belt tension and belt relaxed position, with said lever including spring means for urging said lever and idler pulley toward said belt tension position, and wherein said lever includes a rubber bumper element operatively associated with fixed limit stop means for absorbing impact and for limiting pivotal displacement of said lever and idler pulley in a direction away from said belt tension position during shifting movement of said belt from one of the pulleys to the other pulley.

Claim 11

A variable ratio drive device comprising, in combination: a. base frame means; b. a bushing supported on said base frame means; c. a shaft rotatably supported in said bushing; d. a belt; e. a pair of pulleys supported on said shaft for axial shifting movement relative thereto, with said pulleys being fixed to said shaft for rotary movement therewith, said pulleys being of different diameter and coaxially positioned adjacent each other, with each pulley including wall elements defining grooves in said pulleys, one wall that is disposed between said grooves including a cutout portion to cause said belt to be shifted from one pulley to said other pulley in response to an axial shifting and rotary movement of said pair of pulleys; f. a lever pivotally mounted on said base frame means, said lever including a yoke attached to one end, with said yoke being fixed to said pair of pulleys for rotary movement relative thereto and operable for effecting axial shifting of said pair of pulleys relative to said shaft, with an opposite end of said lever including handle shifting means; and f. a bell crank mounted on said bushing for pivotal movement about an axis substantially parallel to said shaft axis, said bell crank being movable in a plane parallel to the driving plane of said pair of pulleys, with an idler pulley supported adjacent an extended end of one of said bell crank arms and adapted to engage and maintain tension on said belt supported on a selected one of said pair of pulleys, and wherein a tension spring is operatively connected to a second arm of said bell crank for urging said idler pulley to a belt tightening position, and wherein said bell crank includes a rubber bumper element adapted to contact a fixed limit stop means for limiting the pivotal displacement of said idler pulley in a direction away from said spring tension means, with said rubber bumper element detailed for absorbing impact when said idler pulley is rapidly displaced against said spring means during shifting movement of said belt from the smaller pulley to the larger pulley.

Claim 12

A variable ratio drive device comprising, in combination: a. base frame means; b. a bushing supported on said base frame means; c. a shaft rotatably supported in said bushing; d. a belt; e. a pair of pulleys supported on said shaft for axial shifting movement relative thereto, with said pulleys being fixed to said shaft for rotary movement therewith, said pulleys being of different diameter and coaxially positioned adjacent each other, with each pulley including wall elements defining grooves in said pulleys, one wall that is disposed between said grooves including a cutout portion to cause said belt to be shifted from one pulley to said other pulley in response to an axial shifting and rotary movement of said pair of pulleys; f. a lever pivotally mounted on said base frame means, said lever including a yoke attached to one end, with said yoke being fixed to said pair of pulleys for rotary movement relative thereto and operable for effecting axial shifting of said pair of pulleys relative to said shaft, with an opposite end of said lever including handle shifting means; and f. a bell crank mounted on said bushing for pivotal movement about an axis substantially parallel to said shaft axis, said bell crank being movable in a plane parallel to the driving plane of said pair of pulleys, with an idler pulley supported adjacent an extended end of one of said bell crank arms and adapted to engage and maintain tension on said belt supported on a selected one of said pair of pulleys, and wherein a tension spring is operatively connected to a second arm of said bell crank for urging said idler pulley to a belt tightening position, and wherein said bell crank includes a rubber bumper element adapted to contact a fixed limit stop means for limiting the pivotal displacement of said idler pulley in a direction away from said spring tension means, with said rubber bumper element detailed for absorbing impact when said idler pulley is rapidly displaced against said spring means during shifting movement of said belt from the smaller pulley to the larger pulley.