Patent GB-792758-A (GB)
Title: Improvements in and relating to laundry apparatus
IPC: D06F34/30
Filed: 1956-06-04
Abstract: 792,758. Washing-machines. GENERAL ELECTRIC CO. June 4, 1956 [June 2, 1955], No. 17191/56..Class 138 (2). [Also in Group XIII] Laundry apparatus for washing and drying articles contained in a rotating basket 14, includes a drive for rotating the basket, control means for the washing and drying operations, and a safety device which prevents these operations if a member connecting the drive to the basket fails. General arrangement.-The basket 14 is of the end-loading type and is mounted on a driveshaft 20 having a main bearing assembly 29 supported by plates 26, 27 forming the rear end of a tub 15 surrounding the basket 14. The tub 15 is mounted on the base of the machine by means of four supporting bars 92 which provide limited flexibility in a transverse direction. The basket and tub are mounted in an outer cabinet 1 having a hinged door 5 adapted to press against a sealing gasket 24 carried by a front annular wall 2 of the tub 15. The door 5 also presses against the plunger 103 of a switch 102 so that opening of the door 5 when the machine is in operation cuts off the electric supply thereto. Drive mechanism.-An electric motor 31 is connected by a belt 34 and pulleys 33, 35 to a two-speed transmission 36 which drives the basket 14 at either washing or spin-drying speed through a belt 39 and pulleys 38, 40. The transmission 36 can be shifted from low to high speed by energization of a solenoid 37. The transmission 36 is mounted on a sled 41 carrying a pin 43 which is slidably and pivotally received in a bracket 42. A spring 44 biases the sled 41 to the right in Fig. 4 to maintain tension in the belt 34. Tension in the belt 39 is maintained by the weight of the transmission 36 and sled 41, supplemented by a compression spring 46. The sled 41 also carries a toggle switch 50 and a trigger 56 pivotally mounted at 57 Àincluding an upwardly-extending arm 58 adapted to force a switch actuating plate 52 upwardly to disengage a latch 55. On disengagement of this latch the plate 52 is moved to the left in Fig. 4 by a spring 54. Failure of either of the belts 34, 39 causes pivotal movement of the trigger 56 and opening of the switch 50. The changeover from low to high speed rotation of the basket 14 may cause undue vibration of the basket and tub due to tmeven distribution of the clothes. An adjustable member (Fig. 1, not shown), is therefore provided on the underside of the tub 15 to actuate the switch to return the machine to lowspeed rotation if the vibration exceeds a predetermined amplitude. Simultaneously, an unbalance motor 159 comes into operation to reset the switch to its original position and return the machine to extraction speed. If necessary this process is repeated until a practically balanced load is attained. Water supply and discharge.-Solenoids 63 and 64 regulate the supply of hot and cold water respectively to the machine through a common pipe 65. An additional solenoid 66 regulates the supply of cold water at a slower rate through a conduit 67 for condensation purposes during the drying operation. An air gap is provided between the conduits 65, 67 and a common funnel 69 into which they discharge. The funnel 69 is connected to a trap member 71 which prevents suds from rising into the funnel 69. Due to the fact that the condenser water is supplied at a rate less than the available flow capacity through the trap 71 and that the trap 71 acts as a siphon, the condenser water is supplied to the machine in pulses. The conduit 71 enters the tub 15 at 72 near the apex of a liquid spreading bead 73. The water level in the machine is controlled automatically by a diaphragm-operated switch 75 (Fig. 4), connected by a tube 74 to the interior of the tub 15. The machine may be provided with a solenoid controlled gravity drain valve but as shown, a drain pump 76 (Fig. 3), has a belt drive connection to a pulley 79 journalled on a two-part shaft extension 80, 80a driven by the motor 31. The pulley 79 carries a lug 84 adapted to be engaged by an outwardly projecting portion 83 of a torsion spring 81 secured by a screw 82 to the shaft extension part 80a. An internal spring normally forces the part 80a to the left, whereby the torsion spring 81 does not engage the lug 84 and the pump 76 does not function. A solenoid 85 having a plunger 86 is arranged to force the shaft part 80a to the right whenever the machine is to be drained. Alternatively, a separate pump motor or a separate drain valve for a constantly operating pump may be provided. Heating arrangements.-A multi-section heating element 96, 97 mounted within the upper portion of the tub serves for water heating during washing and for moisture evaporation during drying. A temperature sensing bulb located within the tub 15 is connected through a tube 98 to a thermostat switch assembly 99. An additional safety thermostat assembly 101 is provided. A substantial heat transfer takes place between the heaters and the rotating basket, and since the basket dips into the liquid as it rotates the liquid is thereby heated. The control system of the machine is arranged so that thewater heating means cannot be energized during the washing operation unless the machine contains normal operating level of liquid, unless both drive belts are operative, and the main drive motor is rotating at normal speed. An electromagnetically-operated relay is preferably provided to control the heavy current taken by the heaters. The heaters are energized during the major portion of the wash cycle to increase the wash liquid temperature, but during the latter portion of the cycle the heater is cycled from on to off for short periods to compensate for thermal losses. A temperature responsive actuator within the control assembly 99 is arranged to rotate a switchactuating arm (Fig. 5, not shown), about its pivot point. This arm carries at each end a contact co-operating with a stationary contact controlling the heater sections 96, 97, respectively. The pivot point of this arm is offcentre and is adjustable by means of a control knob 13, the arrangement being such that the main heater section 97 is cut out at a predetermined temperature and the other heater section 96 is cut out at, e.g. 20 degrees above the first temperature. The duration of the drying period is determined by the control assembly 99, the timer motor for the machine being deenergized until both heater sections 96, 97 have been cut out. Actuation of the safety thermostat 101 functions not only to terminate operation of the heating element but also to energize the timer motor which drives the sequence control to its off position and terminates machine operation. Operation.-The desired water temperature is selected initially by the operator by depressing a push-button to energize the hot, or hot and cold water solenoids. The desired washing period is selected by adjusting the rotary position of a control knob (not shown). On closing the door 5 and thereby switch 102, the machine immediately commences to fill with water. The timed washing period does not commence until the water has reached the level at which it operates the switch assembly 25. After the washing period the machine is drained and refilled for a first rinse. The machine is again drained and the basket rotated at high speed. After one or more additional rinses, each under the control of the liquid level control assembly 75, the clothes are given a final spin and then dried by means of the heaters 96, 97. The drain pump is operated during the final drying to discharge condenser water and condensate from the machine. The heater relay, drain control solenoid and condenser water valve solenoid are connected in series with a centrifugal switch in the motor 31 so that they can only operate when the motor is running. During the drying operation the water level switch assembly 75 functions as a flood switch to prevent operation of the machine if excessive water is present. A manually-operated switch may be depressed if it is desired to cut out further operation after the final spin dry period. The timer motor is arranged to resume operation during heat drying in the event of belt failure in the drive transmission to the basket 14, in the event of any flooded condition, or. if there is overheating as sensed by the safety thermostat 101. The drying operation is followed by a cool-down period during which the clothes are tumbled without application of heat.