GB1305656A - - Google Patents

Abstract

1305656 Toothed gearing OMP OFFICINE MECCANOPLASTICHE DI PRECISIONE SRL 1 Oct 1970 [4 Oct 1969] 46774/70 Heading F2Q [Also in Division H1] A stepping device, suitable for a washing machine programmer, provides intervals of different durations in any preset sequence and also provides for stopping the stepping for a prolonged period with automatic resumption thereafter. A motor 11 drives a gear 15 via reduction gearing (12, 13, 14, Fig. 2, not shown) and hence a gear 16 secured to gear 15. Gear 16 engages a further gear 17 but is only toothed over part of its periphery such that after a rotation of gear 17 through somewhat more than 90 degrees a spring 19 pressing on a doublenosed cam 18 can snap the gear 17 the remainder of 180 degrees rotation. An axial extension 22 of gear 17 carries two diametrically opposed ribs 23, 24 for co-operation with respective rings of teeth on a gear 10 which is coupled to a main programming cam block (not shown). The ribs 23, 24 are arranged to move in the path of the periphery of gear 10 during the rapid portion of the rotation of gear 17 which thus effectively moves in 180 degree jumps. Where teeth are omitted from the lower ring of teeth on gear 10 the rib 23 is ineffective and the interval between steps of gear 10 is doubled. Any desired sequence of single and double intervals may be preset by the pattern of omission of teeth on gear 10. If a tooth is omitted from both upper and lower rings on gear 10 the latter ceases to be driven and in order to provide automatic resumption of stepping a further partially toothed gear 26 is loosely mounted on shaft A and is normally driven by a pin 25 on gear 10 engaging the end of an arcuate slot (Fig. 4, not shown) in gear 26. Pin 25 is positioned with respect to the double missing teeth on gear 10 such that when the gear 10 ceases to be driven the rib 24 comes into engagement with the toothed portion of the periphery of gear 26 which is thereby stepped until the end of the slot therein entrains the pin 25 and moves the gear 10 one step forward whereby normal stepping is resumed and the toothless portion of gear 26 becomes adjacent to rib 24. A ratchet pawl (27, Fig. 4, not shown) holds gear 26 stationary until gear 10 has moved pin 25 on to the first end of the arcuate slot to step gear 26 until another prolonged interval occurs. The main cam block driven by gear 10 may be set manually, the rib 23 or 24 acting like a pawl on gear 10 under action of the spring 19 on cam 18. Cams R, connected to gears 15, 16, for continuous rotation, may be provided.