GB1273584A - Improvements in or relating to programmers - Google Patents

Abstract

1,273,584. Time switches. CROUZET. 12 June, 1969 [13 June, 1968; 4 July, 1968], No. 29975/69. Heading H1N. A programmer for automatic washing machines which comprises a continuously driven reversing cam 2 arranged to step the programme cam drum 6 is provided with means to suppress the stepping action for a manually adjustable time interval to permit extended soak periods, for example. A member 4, pivoted at 26 on cam 2, rides on the circular inner surface 3a of a fixed member 3 and thus holds the pawl 5 (also pivoted on cam 2) out of engagement with teeth 6a on the cam drum 6 until a recess 3b in the surface 3a is encountered, whereupon the pawl 5 is allowed to engage teeth 6a and step the drum 6. However, a part 7b of a bell-crank member 7 is arranged to bridge the recess 3b and prevent this stepping action whilst in the position shown, as determined by a nose 7a riding on a cam disc 6b of drum 6. A time wheel 8 is steadily stepped by a single-tooth 12a on a shaft 12, which is driven with the reversing cam 2, thereby stressing a spring 9 until a projection 8d on wheel 8 cams a nose 7c of bell-crank 7 to lift it (against spring 16) and remove the part 7b from the recess 3b. The subsequent step of drum 6 causes a rise (not shown) on cam 6b to lift nose 7a even further and an extension 7d then lifts a resilient strip 11 acting as a pawl on wheel 8 so that spring 9 restores wheel 8 to its start position determined by projection 8d abutting a stop 13a on a relatively fixed wheel 13. Drum 6 is then stepped for each revolution of cam 2 until cam 6b allows the nose 7a to return to the position shown, whereupon the pawl 11 reasserts itself and wheel 8 is again stepped while stepping of drum 6 is suppressed until projection 8d again cams the nose 7c. The wheel 13 is normally held stationary by a pawl 17 but can be adjusted by a knob 15, via gears 14, 14<SP>1</SP>, so that the position of the stop 13a (and hence the time interval during which stepping of drum 6 is suppressed) may be varied. In modifications (Figs. 2 and 3, not shown) the pawl 11 is omitted and a part (19a) of bell-crank 7 (corresponding to nose 7c of Fig. 1) co-operates with internal ratchet teeth on wheel 8 to act as a pawl as well as a means of lifting part 7b away from recess 3b. In the modification of Fig. 3 (not shown) the tooth 12a driving wheel 8 is synchronized with the position of pawl 5 on cam 2 such that the drum 6 is stepped immediately the part 7b is removed from recess 3b, and the wheel 8 restores immediately tooth 12a moves out of driving engagement therewith.