摘要 |
The device comprises a worm wheel (1) driven in rotation by a worm (2) coupled to the output shaft (3) of a motor-speed reducer (4), a gear pinion (5) associated with the worm wheel (1) for driving the accessory, and means interposed between the gear pinion (5) and the worm wheel (1) for absorbing the driving torque of the worm wheel when the accessory reaches the end of its travel and stops the rotation of the pinion (5). The shock absorbing means comprise a cam (6) fixed to the pinion (5) and having two opposed surfaces (6a, 6b), a pair of shoes (7a, 7b) in bearing relation to the surfaces (6a, 6b) of the cam and biased thereagainst by a metal spring (8) coaxial with the pinion (5) and the worm wheel (1) and surrounding the shoes, and elements (9a, 9b) drivenly connected to the worm wheel and transmitting to the shoes and to the cam and gear pinion the driving torque of the worm wheel. This arrangement renders the shock absorbing device insensitive to variations in temperature and avoids any play after a certain period of use. |