GB578199A - Improvements in mechanisms for obtaining intermittent movement from a variably oscillatable member - Google Patents

Abstract

578,199. Ratchet gearing. SODECO SOC. DES COMPTEURS DE GENEVE. Dec. 13, 1943, No. 20356. Convention date, Nov. 18, 1942. [Class 80 (iii)] A shaft receives intermittent movement from a variably oscillatable shaft, mechanism being provided by which only the first, or the third, or the fifth &c. movement of the driver is transmitted to the driven shaft. As a modification, the second or fourth, or sixth movement may be transmitted. The mechanism is mainly intended for the control of contactors by means of a finger plate for automatic telephones. The oscillatable shaft 1 mounted in plates 2, 3 is urged always by a spring 4 to an initial position determined by a finger 5 and a stop 6. A gear wheel 7 on shaft 1 meshes with a larger wheel 8 loose on the driven shaft 9 which is also urged to an initial position by a spring 10, finger 11. and stop 12, the effort of the springs being indicated by arrows 13, 14. A ratchet wheel 15 fixed on shaft 9 is engaged by a retaining pawl 16 mounted on a plate 17 and loaded by a spring 18. A disc 19 loose ori the shaft and having a peripheral notch 26 carries a pin 21 which is urged by a spring 20 against a stop 22. A second disc 23, also having a peripheral notch 27, and slightly larger than disc 19, is fixed on the hub of ratchet wheel 15. The gear wheel 8 has a spring-loaded pawl 24 wide enough; Fig. 2, to engage both the discs. Normally the two notches 26, 27 coincide and are engaged by the pawl 24 as in Fig. 1. The first forward movement of the shaft 1 causes wheel 8 to rotate opposite to the 'direction of arrow 14 and the pawl 24 to drive the two discs 19, 23 and therefore the shaft 9. On the return movement of shaft 1, the wheel 8 also returns but the shaft 9 remains stationary being held by pawl 16. The pawl 24 rides back on the periphery of disc 23 and permits the disc 19 to return under the action of its spring. During subsequent oscillations of shaft 1, the shaft 9 remains stationary, the pawl 24 sliding over the periphery of disc 23. At the end of a series of oscillations of the shaft 1, the pawl 16 is released and the ratchet wheel 15 and shaft are allowed to return to their initial positions. The third forward movement, only, of the driving shaft may be transmitted to shaft 9 by the mechanism shown in Figs. 7, 9. The parts already described are supplemented by a stepped cam 31 co-operating with pawl 24 and fixed on a second ratchet wheel 32 loose on shaft 9 and co-operating with a returning pawl 33 and urged by a spring 34 to bring a pin 35 in disc 23 against a pin 36 in ratchet wheel 32. The lower step of cam 31 is of larger radius than that of disc 23 itself larger than disc 19. At the end of a series of oscillations of shaft 1, a rod 44 is moved which, in conjunction with lever 39, link 40, and fingers 41, 42, releases all the pawls simultaneously. By reversing the direction of the ratchet teeth and pawls, the transmission of only the second or fourth or sixth forward movement may be effected.