| 摘要 |
573,282. Toothed gearing. ROTAX, Ltd., and MILLNS, T. W. Dec. 6, 1943, No. 20367. [Classes 80 (i) and 80 (ii)] [Also in Groups XXX and XXXIV] A driving mechanism, more particularly for operating the shutters of an aircraft engine, comprises an' electric motor a which drives through a friction clutch c an epicyclic reduction gear b. Brake shoes k, pivoted on a fixed member j, are controlled by springs n and an annular winding o in circuit with the motor a, to engage a friction drum d<1> on the driven member d of the friction clutch when the motor circuit is opened to arrest quickly the motion of the gear, the clutch c being adapted to slip under the momentum of the motor armature. When the motor circuit is closed, the brake shoes are retracted to release the gear. The brake shoes k are so pivoted that the friction tends to increase the braking pressure and are oppositely arranged in pairs so that this effect is obtained for either direction of rotation of drum d<1>. |
