GB553336A - - Google Patents

Abstract

553,336. Automatic control systems ; thermal switches. LANDIS & GYR SOC. ANON. April 18, 1941, No. 5030. Convention date, April 26, 1940. [Class 38 (iv)] [Also in Group XXXVII] Temperature.-The regulation of temperature, for example, in a room, is effected by a switch controlling the supply of heat and having two contacts subject to two bimetallic spirals one of which is responsive to the temperature to be regulated, e.g. that of a heating medium, and the other is heated by auxiliary means controlled by a thermostat responsive to external conditions; the latter may operate contacts in series with a heating winding causing intermittent current in a second heating winding on the second aforesaid bimetal spiral, or it may control a variometer or transformer adjusting the heating current. The inner end of one spiral may be connected through a cranked spindle to the outer end of the other, which carries a contact. Fig. 3 shows a bimetallic spiral 17 fixed at its outer end to a copper enclosure 28 in contact with heating fluid, its outer end being fixed to a spindle 15 passing through a heat insulator 29. The spindle is secured to the inner end of a second bimetallic spiral 14 the outer end of which is fixed to a copper cup 30 against which an electric heating element 8 is clamped by a nut on a screw 32 secured to the cup 30. The screw is supported in a bearing bracket 31 and the cup 30 is fixed to a heat insulating casing 33, 34 carrying a contact arm 13. The Specification as open to inspection under Sect. 91 described also an arrangement in which the respective spirals operated co-operating contacts. This subject-matter does not appear in the Specification as accepted.