GB480142A - Improvements in or relating to refrigerating apparatus - Google Patents

Abstract

480,142. Refrigerating. WESTING- HOUSE ELECTRIC & MANUFACTURING CO. Feb. 22, 1937, No. 5184. Convention date, March 3, 1936. [Class 29] Compression machines and systems.-A refrigerating system having high and low temperature evaporators is provided with a refrigerant liquid flow control device normally disposed in one position in which refrigerant is supplied to, and vaporized in, the high temperature evaporator, and movable by hand to a second position in which the refrigerant is supplied to, and vaporized in, the low temperature evaporator. Means responsive to a predetermined low temperature in the low temperature evaporator is provided to return the control device to its normal position. A system for a refrigerator cabinet includes an enclosed motor-compressor unit 28, condenser 29, and a low temperature evaporator consisting of interconnected hollow shelves for supporting ice trays and connected in series with a high temperature evaporator consisting of interconnected hollow walls 14, 15 which, together with bottom and end plates 43, enclose the shelves. The control device comprises a vessel 36 having an electromagnetically-operated plunger 37 and interposed between the condenser and the floatvalve chamber 34 controlling the flow of refrigerant to the evaporators. The control device is regulated by mechanism comprising a bracket 61 to which is pivoted a lever carrying contacts 53, 54 and urged to the left by a spring 48 and to the right by bellows 49 connected to a thermostat bulb in contact with the lowest shelf of the low temperature evaporator. The bracket also supports a spring arm carrying flexible contact strips 57, 58 and an adjustable armature 63 which coacts with an electromagnet 64. In the normal position shown, in which refrigerant overflows from the low to the high temperature evaporator, the current supply to the compressor motor is controlled by a thermostat 42 in the cabinet. When the temperature of the air in the cabinet reaches a predetermined value, the thermostat closes the circuit through a starting relay 66 and sets the motor in operation. When it is desired to operate the low temperature evaporator the armature 63 is pressed into contact . with the magnet 64 so that the contacts on the strips 57, 58 abut against the contacts 53, 54 thus completing circuits through the solenoid 39 operating the plunger 37, which is moved to its upper position thus trapping refrigerant in the vessel 36, and the starting relay 66. The control of the current supply through the relay is thus independent of the thermostat 42. When the temperature in the low temperature evaporator reaches a predetermined minimum value, the bellows 49 contracts and the circuits are broken so that the plunger 37 returns to its normal or lower position. The armature 63 may be adjusted to such a position to the right that after it has been pressed into contact with the magnet 64, the thermostat is unable to effect rupture of the circuits. Specification 446,599 is referred to.