Patent GB-661038-A (GB)
Title: Automatic washing machine
IPC: D06F34/08
Filed: 1948-12-22
Abstract: 661,038. Washing and drying machines. RAND WASHING MACHINE CORPORATION, H. J. Dec. 22, 1948 [Jan. 31, 1948], No. 33029/48. Class 138 (ii). A washing machine comprises a flexible liquid and air-tight bag for holding laundry and liquid and has means responsive to energization of a clock mechanism for supplying liquid to the interior of the bag, switch means responsive to a predetermined liquid level for closing the liquid supply means and for starting a laundry agitating means and means responsive to the clock mechanism for stopping the agitating means and for starting and subsequently stopping means for withdrawing liquid and air from the bag to collapse it upon the laundry. General features.-A tub 12 contains a water and air-tight bag 11 within which is an oscillating agitator 20. The tub has a cover 14 which makes an air-tight seal with the bag 11 and a pipe 22 enters the bottom of the bag 11 through which water is supplied to the bag and water and air are withdrawn to produce a vacuum which allows atmospheric pressure to squeeze dry clothing in the bag. The vacuum is produced by an aspirator or by a pump and the operation of the machine is automatically controlled. Constructional features.-The tub 12 is supported on a base 13 containing a motor 17 which drives the agitator through a watertight seal in the bag 11. In one construction the motor 17, also drives the pump. The bag has a resilient bead 11a by which it is snapped over the top edge of the tub and which engages a sealing ring 15 on the cover 14. The cover is provided with a manually operable valve 70 by which air may be admitted to the bag. Water supplying and discharging means.-In the construction using an aspirator 23 for removing water and air from the bag, the inlet of the aspirator is connected to a cold water valve 27, a hot water valve 26 and a warm water valve 28; each of these valves is of the self-closing type and is opened by a solenoid. The outlet of the aspirator is connected to a drain pipe through a solenoid-controlled valve 30 which is also self closing. A pipe 22 leads from the throat 23b of the aspirator to the base of the tube, entering underneath the agitator which is perforated. A diaphragm-controlled switch 37 is connected to the pipe 22 and is operated by a vacuum in that pipe. The switch 37 is connected in the circuit of a timing motor 32. A pressure switch 34 operated by a predetermined amount of water is mounted in the bottom of the tub underneath the bag. The construction in which a pump is used to extract air and liquid from the bag has selfclosing, solenoid-operated hot and warm water valves connected to the inlet underneath the agitator. A branch from this pipe leads to a pump which is driven by the agitator motor. This motor is connected to both the agitator and the pump through a clutch which when the motor rotates in one direction connects the agitator and when it rotates in the other direction connects the pump. The tub inlet is also connected to the atmosphere through a normally open, solenoid-closed valve. Operation.-In the construction using an aspirator, clothing and soap are placed in the bag 11 and a knob 33 which varies the position of a set of cam-switches 31 driven by the timing motor 32, is moved to select the washing period. A switch which selects either the hot water solenoid or the warm water solenoid is then positioned and the knob 33 is moved endwise to operate a master switch in the electrical circuit, a circuit is then completed to either the hot water or warm water solenoids through the cam switch 31 and the water level pressure switch 34. Water flows into the bag through pipe 22 since valve 30 in the aspirator outlet is in its closed position. When water in the bag reaches a predetermined level, pressure switch 34 is operated, this breaks the circuit to the water valve solenoid to shut off the water supply and completes circuits to operate the timing motor and agitator motor. At the end of the washing period the cam switch 31 is operated by the timing motor to stop both the agitator and timing motors and to operate the cold water control solenoid and the solenoid controlling the valve in the aspirator outlet. Water therefore flows through the aspirator and causes a suction in the pipe 22 which removes air and water from the bag 11 allowing atmospheric pressure to squeeze the bag 11 against the clothing to remove liquid. The tub is provided with air holes 12a for this purpose and the cone portion 14a of the cover helps to force the bag down on to the clothing. During this operation the pressure switch 34 is released but does not complete any circuits. When the degree of vacuum in the bag 11 has reached a predetermined amount the diaphragm switch 37 is operated and completes a circuit for the timing motor to time the squeezing operation. After a period the cam switch 31 shuts off the cold water supply, closes the valve 30 and opens the warm water valve 28 to supply rinse water to the bag 11 through pipe 22. The diaphragm switch 37 returns to its original position and stops the timing motor. Water flows into the bag until the switch 34 is operated, this shuts off the water supply and starts the agitator and timing motors. After a period the drying operation is repeated as previously described followed if desired by further rinsing and drying periods. The cam switch 31 then breaks all circuits to terminate the sequence. In the construction in which a pump is used instead of an aspirator, when the master switch is operated as previously described, hot or warm water flows into the bag and eventually operates the pressure switch 34 as previously described. This cuts off the water supply and starts the agitator and timing motors. At the end of the washing period, the agitator motor is disconnected from the supply by the cam switch 31 for one minute to allow it to stop and is then connected so that it runs in the reverse direction, the automatic clutch thereupon disconnects the agitator and drives the pump to remove air and water from the bag to allow atmospheric pressure to squeeze-dry the clothes. During this period the switch 34 changes over but without completing any circuits. After a time the cam-switch disconnects the motor and then operates the warm water solenoid to supply rinsing water to the bag, prepares a circuit for the motor to operate the agitator and switches off the timing motor. When the switch 34 is operated by the water in the bag the agitator and timing motors are started for a rinsing period which is terminated by a drying period as previously described. The rinsing and drying periods are repeated if desired and then the timing motor disconnects all circuits to terminate the sequence. If desired the vacuum may be broken at the end of each drying period by means of the valve 83 (not shown). This is normally open but is closed by operation of its solenoid during the washing, rinsing and drying operations by the cam switch 31. Specification 640,020 is referred to.