GB596254A - A thermoresponsive device for electrical controlling apparatus - Google Patents

Abstract

596,254. Thermal switches. BARKER, H. (Sauter Akt.-Ges. Fabrik Elektr. Apparate, F.). July 20, 1945, No. 18594. [Class 38(v)] [Also in Group XXXV] A mercury or other switch 1 for regulating a physical quantity, e.g. the temperature in a hotwater pipe, is carried by a joist 2 connecting the ends of two bimetal strips 5, 6 carried, in turn, by a beam 9 pivoted at 7. On a fall in the temperature, a link 8 moves upwards, as shown, and tilts the switch so that the ;contact 12 is made, thereby energising a reversible motor 14, controlling the element to be regulated, and the heater 11 of the bimetal strip 6. After a certain time this bimetal returns the switch to its central position, cutting out the motor and the heater 11, and, if the temperature has not been fully regulated, the switch moves back to the tilted position as the strip 6 cools down. In Fig. 4 (not shown), a temperature-responsive contact moves over a resistance feeding the two coils of a differential relay, whose armature actuates the motor and heater contacts. In Fig. 5 (not shown), the ends of two straight bimetal strips are joined by a link engaging one end of a pivoted contact. In a further modification, the bimetals are connected by springs to the joist 2 which is itself pivoted, Fig. 6 (not shown). In Fig. 7 (not shown), two straight bimetals are connected by springs to a pivoted contact.