Patent GB-743047-A (GB)
Title: Improvements in and relating to automatic washing machines
IPC: D06F34/08
Filed: 1953-11-13
Abstract: 743,047. Washing machines. GENERAL ELECTRIC CO. Nov. 13, 1953 [Nov. 14, 1952], No. 31556/53. Class 138 (2). The Specification relates to an electrically - operated automatic washing-machine of the kind having an agitator (not shown) operating within a tub 36 arranged for rotation in a casing 22, valve mechanism 79 for controlling the supply of water to the tub, the casing 22 being arranged to catch excess water overflowing from the tub during filling thereof and water centrifuged from the tub during rotation thereof, a drain trap 69 below the casing having a drain conduit 68 connected thereto and a drain pump 47 for pumping water collected in the drain trap to an exterior outlet, a drive motor 42 connected to the pump 47, a multiposition programme selector switch 85 having an " off position, a " fill " position and a plurality of control positions for controlling the operation of the valve mechanism 79 and drive motor, and a timer motor 92 for operating the selector switch through the remainder of its positions from a manuallyselected position to its " off " position. According to the invention the water collected in the drain trap 69 is arranged to operate a control switch 77 which controls the operation of the valve mechanism 79 when the selector switch is in its " fill " position and permits the timer motor 92 to operate whereby the selector switch is operated through its control positions for selectively operating the agitator, rotating the tub 36 and operating the valve mechanism 79 in order to carry out in a predetermined cycle, washing, rinsing and water extracting operations upon clothes in the tub 36. The switch 77 is normally open and is closed by the pressure of water acting on a diaphragm 74 connected to the switch 77 by an arm 78. The invention is applied to the machine described in Specification 704,643. Solenoids 83, 84 control the admission of hot and cold water respectively to the tub 36 through a conduit 82. Hot, warm or cold water is admitted to the tub for washing according to the position of a control dial 91 connected by a shaft 90 to a switch wiper arm 112. Solenoids 61, 62 control the rotation of the tub 36 and operation of the agitator respectively. The timer motor 92 is connected through reduction gearing 94 and a slip clutch 96 to a shaft 86 carrying cams C1 ... C6 operating switches S1 ... S6 respectively. A manually-operated control dial 88 rotates with the shaft 86 but is free to be moved axially with respect to the shaft, an annular disc 98 moving with the control dial 88 to open and close a master switch 99. Operation.-The dial 91 is rotated to the hot, warm or cold position, and the control dial 88 lifted to close switch 99 and then rotated to the desired washing interval. The drive motor 42 starts and the pump 47 discharges any residual water in the drain trap 69. The timer motor 92 does not start until the switch 77 is closed by water overflowing from the tub 36 so that filling of the tub is independent of the water supply pressure. Closing of switch 77 also energizes solenoid 62 whereby the agitator is started and a bridge member 115 operated. The member 115 opens the circuit through the hot and/or cold water solenoids 83, 84, and completes an alternative circuit through the solenoid 62 and timer motor 92 to ensure operation thereof after switch 77 has re-opened. The washing period is followed by a spin period during the last part of which warm water is supplied to the spinning tub 36. The tub is then braked and cold water supplied to the tub until it overflows and operates the switch 77 to cause oscillation of the agitator and closing of the valve mechanism 79. After a predetermined time the valve mechanism is again opened to supply cold water to the tub for an overflow rinse with the agitator still operating. The timer motor 92 next rotates the switch 85 to the final spin position in which the cold water solenoid 84 and agitator solenoid 62 are de-energized and the solenoid 61 is energized to spin the tub. Finally the tub is braked and the switch 85 moved to its " off " position. Modification.-Fig. 5 (not shown), illustrates a modified control circuit in which the two dials 88, 91 of Fig. 3 are combined, the control dial bearing hot; warm and cold-filling positions. The hot and cold solenoids are electrically interlocked so as to prevent subsequent operation of either in the event of prior operation of the other, but permitting simultaneous operation of both. The hot and cold solenoids are each provided with an armature controlling switches in the control circuit and the control switch (77) is provided with normally open and normally closed contacts.