| 摘要 |
Known cam and roller-ramp overrunning clutches depend on frictional forces to effect a kinematic lock between the driven and driving members and they are dynamically limited to a specific engagement-disengagement cycle. In the present invention the transmission of torque between the driving and driven members is accomplished by a worm/worm-wheel combination such that dependence on frictional forces is eliminated. The congruent surfaces of the lands on the worm and the teeth of the worm-wheel are sloped so that there is normal free-wheeling of the worm upon rotation of the worm-wheel in one direction but there is locking action upon rotation of the worm-wheel in the other direction. The lead angle of the worm is such that the worm would normally be free-wheeling in either direction of rotation. Because engagement and disengagement is positively programmed the application of the locking elements is not limited kinematically to any specific cycle.
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