Patent GB-981589-A (GB)
Title: Improvements relating to washing machines
Inventor: DUNN HAROLD GEORGE
IPC: D06F34/08
Filed: 1960-05-13
Abstract: 981,589. Spin driers. HOOVER Ltd. May 4, 1961 [May 13, 1960], No. 17084/60. Heading F4G. [Also in Division D1] In an automatic washing and/or spin-drying machine a sequence controller comprises pairs of contacts 1-18 actuated by cams (not shown) rotated through thirty-six successive positions or steps by a timer motor 32, the cams being mounted on a shaft (not shown) carrying brushes (not shown) which in predetermined positions of the cams engage with stationary electrically-conducting segments I-X arranged in two or more concentric rings. Each step made by the cams and brushes initiates an operation in a master programme of washing operations (Figs. 2a, 2b, not shown), some of which are omitted to produce sub-programmes (Figs. 3, 4, not shown) by actuation of pairs of contacts a-i and k-q in a pre-selector switch. The supply is connected at 20, 21 and contacts 13 are closed throughout the programme of operations whereby motor 32 rotates continuously. Resistor 33 is periodically short-circuited by appropriate contacts thereby causing the rotor of motor 32 to be displaced axially, engage the shaft carrying the cams and brushes, and advance them to their next position. A holding contact 34 ensures short-circuiting of resistor 33 until the advancement of the cams and brushes is complete. A washing operation may be terminated by closure of any of contacts 34, 36, 37 after intervals of one quarter, one and two minutes, respectively, by a cam rotated by motor 32. The network shown also includes solenoid-actuated valves 22, 23 for hot and cold water supplies, respectively, a water heater 24, main and starting windings 25, 26, respectively, of a drive motor for the machine, a capacitor 27 for the drive motor, a solenoid-actuated clutch 28 for an impeller (not shown), a motor 29 for a scavenging pump (not shown), and switches 30, 31 responsive to the level of liquid in the machine. When liquid is drained from the machine the operation is terminated by closure of switch 31 when the liquid reaches a predetermined low level and the operation is not subject to a time limit by closure of any of contacts 34, 35, 36. This operation is followed by a further pumping operation for a predetermined period e.g. one minute, to ensure adequate draining of the machine before the next stage in the washing cycle is begun. This further pumping operation is terminated by closure of one of the contacts 34, 35, 36. Filling operations are controlled by switch 30 and high-speed rotation of the clothes container (not shown) for centrifuging is effected by operating the drive motor in reverse. Contacts r, i, h are shunted by thermostats responsive to the temperature of liquid in the machine and set to operate at 40, 60 and 85 C., respectively, during liquid heating operations. The contacts k may be closed during some of the sub-programmes (Fig. 3) whereby the cams and brushes are advanced to their next operational position to interrupt a filling operation with hot water in the event of the water temperature exceeding that required for the washing operation, in other subprogrammes contacts e may be closed to allow the filling operation to be completed without interruption. Specifications 877,429, 877,430 and 946,666 are referred to.