GB940105A - Control apparatus - Google Patents

Abstract

940,105. Thermal switches. RANCO Inc. March 19, 1962, No. 10378/62. Heading H2B. Control apparatus 10 comprises a frame 11 to which is attached a condition responsive element 30 which governs the movement of a plurality of control members such as a switch operating plunger 24, a part 30g of element 30 engaging means in the form of a channel shape lever 31 providing a pivotal axis 38 for supporting a plurality of beams such as beam 34 for pivotal movement about said axis which is laterally translatable in response to a change in said condition, and an abutment 39a with which one end of beam 34 is maintained in engagement for pivotal movement thereabout when the pivotal axis provided by said supporting means 31 is translated, an opposite end of the beam, during pivotal movement of said one end thereof, engaging the control member 24 for moving said member. Element 30 comprises a bellows 30a, a tube 30b, and a bulb 30e containing thermally responsive liquid, and the lever 31 carries four beams 34 ... 37 on a pivot pin 38, each with ends engaging four switchplungers 24, 24b, 24c, 24d, for operating their respective snap-action switches in a predetermined sequence. The right-hand beam ends carry adjustable screws 40 ... 40d engaging a common stop plate 39a forming the abutment therefor, plate 39a being part of a U-shaped lever 39 pivoted on a pin 32 which also forms the pivot for lever 31. The temperatures at which the individual switches are operated in response to expansion of bellows 30a are independently regulated by adjustment of screws 40. The temperatures at which they are actuated in the opposite phase are regulated by adjustment of screws such as 27 to adjust the position of the fixed contacts 22 of the switches. The height of stop plate 39a is adjustable by moving lever 39 about pivot 32 by a manually adjustable cam 46 on a shaft 47.