Variable speed drive
First Claim
1. A variable speed drive comprising a frame;
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
a double pulley variable speed sheave assembly;
a first belt reeved about said driving pulley and sheave assembly;
a second belt reeved about said driven pulley and sheave assembly;
first means including a bell crank having a pivot, a first arm carrying said sheave assembly and a second arm;
means for shifting the position of said sheave assembly with respect to said driving and driven pulleys for altering the drive ratio of said sheave assembly through a range of low to high speed operating positions;
means for attaching the shifting means to the second arm;
second means pivotally connected to the bell crank pivot and the frame and means for biasing said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension and for variably controlling the magnitude of driving tension forces on said first and second belts in accordance with operating speed.
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Accused Products
Abstract
A variable speed drive for a riding lawn mower or the like has a double pulley variable speed sheave assembly coupled between a driving pulley and a driven pulley by first and second V-belts, respectively. The sheave assembly is carried at one end of a bell crank which is centrally pivoted to one end of a pivot arm. The pivot arm is pivotally connected to the vehicle frame and is biased to urge the sheave assembly toward an operating position with the belts under driving tension. A mechanical control linkage is connected to the other end of the bell crank, and is operable to shift the sheave assembly with respect to the driving and driven pulley to alter the sheave assembly drive ratio in a manner such that belt tension varies with variations in operating speed. The control linkage is operable to move the sheave assembly between a stopped position with both belts declutched and a range of low to high speed operating positions, and is springably biased to urge the sheave assembly toward said stopped position.
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Citations
23 Claims
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1. A variable speed drive comprising a frame;
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
a double pulley variable speed sheave assembly;
a first belt reeved about said driving pulley and sheave assembly;
a second belt reeved about said driven pulley and sheave assembly;
first means including a bell crank having a pivot, a first arm carrying said sheave assembly and a second arm;
means for shifting the position of said sheave assembly with respect to said driving and driven pulleys for altering the drive ratio of said sheave assembly through a range of low to high speed operating positions;
means for attaching the shifting means to the second arm;
second means pivotally connected to the bell crank pivot and the frame and means for biasing said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension and for variably controlling the magnitude of driving tension forces on said first and second belts in accordance with operating speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
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14. A variable speed drive comprising a frame;
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
a double pulley variable speed sheave assembly;
a first belt reeved about said driving pulley and sheave assembly;
a second belt reeved about said driven pulley and sheave assembly;
a bell crank including a pivot movably mounted with respect to said frame a first arm carrying said sheave assembly and a second arm;
a control linkage pivotally connected to said second arm for moving said bell crank with respect to said frame to shift the position of said sheave assembly with respect to said driving and driven pulleys to alter the drive ratio of the sheave assembly between a stopped position and a range of low to high speed operating positions;
means including an arm pivotally connected to the bell crank pivot and to the frame; and
means for biasing said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension and for variably controlling the magnitude of driving tension forces on said first and second belts in accordance with operating speed. - View Dependent Claims (15, 16, 17)
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
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18. A variable speed drive comprising a frame;
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
a double pulley variable speed sheave assembly;
a first belt reeved about said driving pulley and sheave assembly;
a second belt reeved about said driven pulley and sheave assembly;
a bell crank having a pivot and a first arm with said sheave assembly mounted at one end thereof;
a pivot arm having opposite ends with one end pivotally connected to the pivot of said bell crank, said pivot arm being pivotally connected to said frame;
said bell crank including a second arm;
a control linkage connected to the second arm of said bell crank and operable to shift the position of said sheave assembly with respect to said driving and driven pulleys to alter the drive ratio of the sheave assembly between a stopped position and a range of low to high speed operating positions; and
means for biasing said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension and for variably controlling the magnitude of driving tension forces on said first and second belts in accordance with increases in operating speed. - View Dependent Claims (19, 20, 21)
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
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22. In a variable speed drive having a frame with a driving pulley, a driven pulley, and a double pulley variable speed sheave assembly respectively rotatably positioned with respect thereto, first and second belts respectively reeved about said driving pulley and sheave assembly and said driven pulley and sheave assembly, and first means carrying said sheave assembly for shifting the position of said sheave assembly with respect to said driving and driven pulleys for altering the drive ratio of said sheave assembly through a range of low to high speed operating positions, the improvement comprising a bell crank including a pivot, a first arm for rotatably mounting said sheave assembly, and a second arm, means for pivoting said bell crank, and for attaching the pivoting means to the second arm of the bell crank and an arm for pivotally supporting said bell crank, means for pivotally mounting the arm from said frame, and a spring for biasing said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension varying in accordance with increases in operating speed.
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23. A variable speed drive comprising a frame;
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
a double pulley variable speed sheave assembly;
a first belt reeved about said driving pulley and sheave assembly;
a second belt reeved about said driven pulley and sheave assembly a bell crank including a;
first arm carrying said sheave assembly and a second arm, and a linkage connected to the second arm for shifting the position of said bell crank to move said sheave assembly with respect to said driving and driven pulleys for altering the drive ratio of said sheave assembly between a stopped position and a range of low to high speed operating positions;
dead man control means for biasing said bell crank to move said sheave assembly toward said stopped position; and
second means for biasing said bell crank to move said sheave assembly generally away from said driving and driven pulleys to maintain said first and second belts under driving tension and for variably controlling the magnitude of driving tension forces on said first and second belts in accordance with operating speed.
- a driving pulley and a driven pulley each rotatably mounted with respect to said frame;
Specification