GB1297102A - - Google Patents

Abstract

1297102 Thermal switches DANFOSS AS 8 Jan 1970 [14 Feb 1969] 976/70 Heading H1N An electric switch includes a movable contact 55, 56, a fixed contact 54, a closing spring 57, 59 for pressing contact 55, 56 against contact 54 snap-action means comprising spring 40 and an operating arm 24 whose displacement is determined by stops 20 and 52, Fig. 1 (not shown), at least one of which is adjustable, an actuating element 49 for lifting contact 55 56 from contact 54, element 49 being operated by arm 24 and being separated from contact 55, 56 immediately after the time of closing of the contacts, and means for adjusting the strength of the closing spring 57, 59 and snap spring 40. Contacts 55, 56 are mounted on leaf springs 57, 59, the bias of which is adjustable by set-screws 63, 64. Actuating element 49 is part of a block 26 mounted on the free end of arm 24 which is a bimetal, block 26 also carrying a stirrup presenting a knife-edge bearing 38 on which and on a fixed bearing 14 is supported omega spring 40 which, when bimetal 24 has moved sufficiently, snaps over block 26 to change over the contacts. Omega spring 40 is adjusted by a screw 42, Fig. 3 (not shown), which moves the stirrup thus adjusting the gap between bearings 38, 14. The required room temperature is set by a knob 3, Fig. 1, moving through spindle 22 a cam 23 bearing on adjusting screw 30 on a second bimetal 29 fastened to bimetal 24, the assembly of the two bimetals being pivoted. The purpose of the invention is to reduce contact rebound.