| 摘要 |
<p>875,419. Coaster hubs. FICHTEL & SACHS A.G. May 19, 1960 [July 15, 1959], No. 17754/60. Class 136(2). A drive and brake unit for free wheel hubs comprises a driving member 26 and a driven member 40 both rotatable and connected by a' screw thread so that the driven member is movable axially along the driving member from a torque-transmitting end-position to a brakeapplying end-position; stops which engage each other over surfaces normal to. the said end-faces, being formed on the adjacent endfaces of the members 26 and 40. The member 40 is screw-threaded internally to engage the screw boss 30 of the member 26. A chainsprocket-wheel 12 drives a sun and planet gear (shown diagramatically at 20) which turns the driver member 26. The driven member 40 carries spring pawls 50 which engage with a ratchet surface 52 inside the hub case 10 to drive the latter in the forward direction. On back-pedalling the pawls override the ratchet and the member 40 moves along the screwed boss 30 to engage a conical surface 44 inside a brake drum 46 and to expand it against a brake surface 48 inside the hub 10. The stops are in the form of a diametral groove 54 cut in the end face of the member 40 into which lugs 60 on the member 26 can enter to engage with the side-faces of the raised parts 56 when the two members are screwed together. The stops may be manufactured by cold-forming.</p> |
