| 摘要 |
1465584 Power steering systems ROBERT BOSCH GmbH 8 March 1974 [10 March 1973] 10405/74 Heading B7H [Also in Division F2] A servo assembly, particularly for use in a vehicle steering apparatus, comprises a manually actuable drive shaft 10 connected to an output shaft 11 via a torsion member 12, and a clutch including a spring 23 which transfers drive from a gear-wheel 21 driven by an auxiliary motor to the output shaft when the shafts 10 and 11 are rotated relative to each other beyond a given angle. A cup-shaped member 13 having an axial slot 15 in its side wall 14 is fixed to the drive shaft 10 and receives the ends 24, 25 of the spring and a dog 18 fixed via a cylindrical member 17 to the output shaft 11. When the shafts are relatively undeflected, for example in a straight ahead driving position, if the auxiliary motor is accidentally started the spring is rotated with gear-wheel 21, because of its light frictional engagement therewith, until an end 24 engages the side of slot 15. Continued rotation of the gear-wheel will cause the spring to contract and no auxiliary motor assistance is transferred to the output shaft. If the shafts are relatively deflected through an angleα, or a greater angle, rotation of the gear-wheel brings an end of the spring into contact with the dog 18 before the other end contacts a side wall of the slot 15. This causes the spring to expand increasing its frictional engagement with the gear-wheel and transferring the motor drive to the output shaft. When the relative angle of deflection drops below valueαthe other spring end can contact an edge of slot 15 and the spring is contracted to disengage the clutch. |
