Patent GB-514440-A (GB)
Title: Improvements in or relating to washing devices for dishes and the like
IPC: D06F21/00
Filed: 1938-05-05
Abstract: 514,440. Washing dishes. HOBART MANUFACTURING CO. May 5,1938, No. 13439. Convention date, May 5, 1937. [Class 138 (i)] A machine for washing dishes &c. including a washing chamber 12 and means for supplying washing fluid thereto has control means for making the operation of the machine ' dependent on the wash water being at a requisite sterilization temperature, say above 160F., and for ensuring .the requisite duration of the washing operation. The wash water in the sump 15 is supplied by a pump 16 driven by a motor 17 through a control valve 18 to a header 19 and rotary wash arm 20 below the washing chamber 12, a second wash arm preferably being provided above the chamber. The wash water control valve 18 and rinse water control valve 36 are controlled by a handle 25 provided with a disc 30 projecting in the way of the sliding doors 11 of the washing chamber, notches 31 in the disc permitting the doors to be opened only when the handle 25'is in neutral position and the disc preventing opening of the doors when the handle is moved into positions W for washing or R for rinsing. Steam for heating the wash water is admitted from a pipe 51 and valve 50 under control of a thermostat 52. The control handle 23 operates a vertical shaft 26 which actuates the wash water valve 18 through a linkage 28 and the rinse water valve 36 through an arm 40, roller 41, lever 42 and plunger 44. The operation of the pump motor 17 is controlled by a starter switch 56 and stop switch 57 in a control box 55. Switch 56 closes the circuit of a relay 59 to the motor, but the relay circuit is not maintained when switch 56 is released unless a holding circuit has been established by a thermostatic control 58 dependent on the water being at the requisite sterilizing temperature. Above the washing chamber 12 is a box 60 containing the mechanism for controlling the period of the washing operation and preventing movement of the control handle 25 until this period has elapsed. When the handle 25 is moved to open the control valve 18 an arm 62 on the shaft 2'6 actuates a link 63 and switch 66, thus closing a circuit to a suitable automatic time relay 70, a switch 71 at the same time closing a circuit to a solenoid 72 actuating a linkage 74 and moving a pin 75 into the range of movement of the arm 62, thus holding the latter until at the end of the predetermined period the time relay 70 opens the circuit of the solenoid 72, permitting arm 62 to be returned when desired. A window 77 illuminated by a lamp 78 in the circuit of the solenoid 72 indicates the period during which the arm 62 is locked. In the modification shown in Fig. 6, wherein no interlocking mechanism for the doors is made use of, the control of the washing operation is secured by the starting and stopping of the pump motor 80, which is started by the starter switch 82 and relay 81 maintained by the holding circuit 84, including thermostat 86 and its holding switch 85. Starting of the motor 80 closes the circuit 88 of the time relay 87, in response to which a switch 89 closes and bye-passes the stop switch 83 so that operation of the latter has no effect during the predetermined period of operation of the time relay.