| 摘要 |
996,006. Thermal switches. M. CLAUSEN, [trading as DANFOSS VED. ING. M. CLAUSEN [firm of]]. June 27, 1961 [June 27, 1960], No. 23235/61. Heading H2B. An evaporator thermostat having an adjustable temperature range and semi-automatic defrosting, includes an adjustment spring 2 biasing a lever 1 and an auxiliary spring 18 arranged between lever 1 and a trip lever 17 pivoted to lever 1 at 19. Spring 18 is stronger than spring 2 and normally therefore levers 1 and 17 move rigidly together under control of a bellows 3 to actuate contacts 14 via a snap spring 9 and lever 8. When defrosting is to be initiated, a button 26 is depressed, thereby tilting a lever 24 counter-clockwise to the Fig. 3 position where it is latched by the end 20 of lever 17 and wherein it opens contacts 14. Expansion of the bellows causes movement of lever 1 until it abuts a fixed stop 16 whereupon spring 2 is rendered inoperative and its place taken by spring 18 until lever 17 is moved sufficiently to place its end 20 opposite an aperture 25 in lever 24 which is thereby released for return to its initial position. In a second embodiment (not shown), levers 1 and 17 are co-pivoted and directly actuate contacts 14, and act on a further set of contacts also acted on by the defrost button. |
