摘要 |
PCT No. PCT/GB82/00171 Sec. 371 Date Feb. 7, 1983 Sec. 102(e) Date Feb. 7, 1983 PCT Filed Jun. 9, 1982 PCT Pub. No. WO82/04497 PCT Pub. Date Dec. 23, 1982.A thermostatic switch unit for controlling a freezer or, for example, refrigeration apparatus in automotive air conditioning, includes a switch (1) which is acted upon by a thermostat mechanism responsive to the working temperature of the evaporator so as to maintain this temperature within a normal working range which is presettable by means of a control knob (18) in a conventional manner. By depressing manually a push button (26) mounted centrally in the control knob a spring loaded trip lever (29) is rotated to release a spring loaded lever (35) into engagement with a switch operating plunger (2, 3), closing the associated switch contacts (21) and causing the compressor motor of the apparatus to run until a low temperature, below the preset working range of the equipment, is reached, when the latch mechanism (29, 35) is reset automatically by the temperature sensing bellows (8) acting through the operating lever (4) of the thermostat mechanism. Such a semi-automatic temperature pull-down cycle can be selected by the push button (26) irrespective of the setting of the working temperature control knob (18).
|