| 摘要 |
976,583. Ratchet gearing. AMERICAN MACHINE & FOUNDRY CO. Feb. 14, 1962 [Feb. 14, 1961], No. 5718/62. Heading F2Q. A ratchet wheel 10 comprises alternate major teeth 19 and minor teeth 20, each major tooth 19 having an apex and each minor tooth 20 having flat side surfaces 21, 22 which lie in planes A, B passing through the apices of adjacent major teeth 19. The wheel may be driven in either direction by selective operation of pawls 11, 12 mounted on arms 23, 24 which are pivotally mounted on a shaft 25. Each pawl has a rounded edge 37, Fig. 3, which pivots about a lug 28, and an elongated slot 39 through which a stud 40 passes. A spring 41 on the stud 40 biases the pawl into engagement with a flange 27 on the arm. A member 42 provides lateral guides and stop surfaces 47 . . . 47. Detent pawls 13, 14 are pivotally mounted on the shaft 25 and are connected by a spring 48. Detent pawls 14, 13 are interlocked with arms 23, 24 respectively. Over-running is prevented by the engagement of a face of a minor tooth with a pawl, as shown by the position of pawl 11. Specification 976,584 is referred to. |
