Patent GB-465684-A (GB)
Title: Improvements in and relating to dish washing machines
IPC: A47L15/46
Filed: 1936-03-27
Abstract: 465,684. Dish-washing machines. BRITISH THOMSON-HOUSTON CO., Ltd. March 27, 1936, No. 9193. Convention date, March 28, 1935. [Class 138 (i)] A dish-washing machine comprises a vat provided with valves for supply and drainage of liquid to and from the vat, the valves being controlled by auxiliary switches adapted to be operated by means of a motor which is controlled responsively to the operation of a master switch. In the construction shown in Figs. 1 and 3, a vat 10 is provided with racks for holding dishes and is fitted with an impeller 19 adapted to be driven by an electric motor 20. Cleansing liquid is supplied to the vat through a reaction nozzle 27 which receives liquid from a supply pipe 34, under the control of a normally-closed valve 35. A drainage port 38 in the vat is adapted to be closed by a valve 41 normally in the open position. A receptacle 50 containing detergent solution supplies liquid to the vat when water enters the receptacle through pipes 52, 51, the supply of water being controlled by a normally-closed valve 53. The valves 35, 41, 53 are operated electromagnetically against spring action. The vat 10 is mounted within a casing 11 which is provided with a motor 70 adapted to control the rotation of a cam shaft 68. The motor itself is under the control of a master switch 58 provided with a manually-operable member 58a connected to a contact arm 59 which is adapted to co-operate with fixed contacts. The operation of the apparatus is as follows : When the member 58a is moved from the " off " position, which is the position shown in Fig. 3, to its first controlling position, the arm 59 engages contact 59a, whereby the motor 20 is energized. The motor is connected by means of a.flexible shaft to a driving socket in the top of the casing so that any auxiliary appliance connected to the socket may be operated when the motor is energized. To effect a washing operation the member 58a is moved to the second position, in which the arm 59 engages contacts 59b, 59c. A circuit through contact 59b is completed to energize the motor 20 and to energize electromagnet 46 which operates to close the drain valve 41. A circuit through contact 59c is completed to energize electromagnet 37 whereby valve 35 is opened to permit supply of liquid to the vat. The liquid, which is splashed over the dishes by the impeller 19, accumulates in the vat and eventually imposes a load on the impeller necessitating such a current through the motor as will energize a coil 83 sufficiently to open a switch 85. The electromagnet 37 is then de-energized and the valve 35 is closed to cut off the flow of liquid into the bat. The washing action of the impeller continues however while the control member 58a is in its second position. When the member 58a is moved to the third position, contacts 59e, 59f are closed whereby automatic control of the apparatus takes place to effect washing and rinsing operations in a timed cycle. The electromagnet 46 which was energized when the arm 59 engages contact 59b is maintained operative by a holding circuit from the negative side of the supply source 69, through contact arm 59, contact 59f, switches 72, 71, and electromagnet 46 to the position side of the supply source. The electromagnet in addition to closing the switch 71, closes also the switch 87. A circuit for the motor 70 is thus completed through the arm 59, contact 59f, switch 87 and winding 70b of the motor. The motor will then rotate cams 64 .. 67, 74 and 75. Cam 75 almost immediately closes contacts 73 to provide a holding circuit for the motor 70. Cam 65 closes contacts 61 to complete a circuit through electromagnet 37, so that inlet valve 35 is opened, and water enters the vat through nozzle 27. Cam 74 opens switch 72, whereby the electromagnet 46 is de-energized and the drain valve 41 is moved to its open position. The dishes are thus sprayed with water which flows through the nozzle 27 into the'vat, escaping through the opening 38. Eventually cams 64, 67 close contacts 60, 63, respectively, whereby the impeller motor 20 is energized and the drain valve 41 is closed. The water accumulates in the vat and is thrown upwardly to wash the dishes by the impeller, the inlet valve 35 closing when a predetermined amount of water has entered the vat. Cam 66 closes contacts 62 whereby electromagnet 56 is energized so that valve 53 is opened and detergent is caused to flow into the vat from reservoir 50. The washing operation continues until cam detents 65b, 66b, 67b permit notches 61, 62, 63 to open. Switch 63 causes the drain valve 41 to open. The load on the motor 20 decreases so that switch 85 closes but the inlet valve remains closed since switch 61 is open. Switch 62 causes the flow of detergent to cease. Further movement of the cams closes switches 61, 62, 63 to produce a second washing operation which continues until the cam detents 64b, 65d, 66d, 67d permit switches 60 ... 63 to open. The water is then drained from the vat and the motor 20 is de-energized. Subsequently switch 61 is closed whereby the inlet valve 35 is opened and water flows through the nozzle 27 to effect a final rinsing action on the dishes. This action continues until cam 75 permits switch 73 to open whereby the motor 70 is de-energized. Just previously to this, detent 65f permits switch 61 to open, whereby inlet valve 35 is closed. During the manual and automatic operations described a signal lamp 76 is energized through a switch contact 59d. This lamp is de-energized when the member 58a is returned to its " off " position. In the form shown in Fig. 5, the impeller motor 88, fluid supply valve 89, drain valve 91 and detergent supply valve 89, are not controlled directly by the master switch, but are controlled completely by the operation of a motor 104, which in turn is under the control of the master switch 106. The motor 104 is arranged to rotate in both directions, being provided with a forward field winding 104a and a reverse field winding 104b. The motor is controlled by the master switch provided with a switch arm 106a connected to a manually-operable control member 107. The motor is adapted to drive a shaft on which are mounted cams 99 .. 102, 112, 113, 117, 118, 119. When the arm 106a is moved in a counter-clockwise direction to a first position, switch contact 106b is closed to cause the motor 104 to rotate in a forward direction, advancing the cam shaft until the switch 116 is open. The motor stops, but a circuit is complete through closed switch 95 whereby the impeller motor 88 is energized and a driving socket connected thereto, and which may be provided with an auxiliary appliance, is caused to rotate. Movement of the arm 106a to engage contact 106e causes a rinsing action to take place, the water issuing from the reaction spray device and discharging through the drain exit. When the arm 106a engages contact 106f, the drain valve 91 is closed and a washing operation takes place. If the arm 106a is moved to the " off " position the motor 104 is energized to move in the reverse direction and bring the cam shaft to the position shown in Fig. 5. To effect an automatic cycle of operations the arm 106a is first moved to engage contact 106g, whereby the motor 104 moves in a forward direction. Switches 110, 111 are closed and also the switch 96 which causes valve 89 to open and admit water to effect rinsing. The arm 106a is then moved to engage contact 106i whereby a holding circuit for the motor 104 is provided through the closed switch 111. The rinsing operation continues until the drain valve 91 is closed by the operation of cam 102 closing the switch 98. Cam 99 closes the switch 95 to cause the operation of the impeller motor 88 effecting the washing operations, detergent being supplied by the operation of valve 90. Subsequently the washing liquid is drained off, water and detergent are again supplied, and a second washing is effected followed by a second draining operation. Then a. final rinsing action takes place. The motor 104 is deenergized when the depression 113a of cam 113 permits switch 111 to open. When the arm 106a is moved to " off position, a circuit through closed switch 110 causes movement of the motor 104 in a reverse direction until the switch 110 is opened. Specification 433,444 is referred to.