GB815111A - Improvements in and relating to electrical energy regulators - Google Patents

Abstract

815,111. Thermal switches.. DIAMOND H SWITCHES Ltd. March 13, 1957 [March 13, 1956], No. 7836/56. Class 38 (5). In a " cycling " switch for controlling the energy input to, for example, a hot-plate, the motion of a bimetallic member 1 pivoted at 5 in its plane is converted into motion in another plane by a lever 19 pivoted at 21 to actuate the current supply switch 27. The bimetallic member 1 comprises separate bimetallic elements 2, 3 rigidly connected by a bracket 4. Element 2, which acts as an ambient temperature compensating means, carries a screw 7 which engages an energy-input adjustment cam 8 manually rotated by a spindle 10 carrying a dial. Element 3 has a heater 14 connected in parallel with the hot-plate element wound thereon. With the dial in the " off " position, a raised part 40 of the cam engages the screw 7 so that the switch 27, which is biased to closure, is held open. When the dial is rotated to an " intermediate heat " position, the screw 7 engages a cam part 41 of decreasing radius so that the switch is intermittently actuated by the bimetallic element 3 and when the dial is turned to the " full position the screw 7 engages a flat 42 on the cam so that the bimetallic element 3 is unable to actuate the switch which therefore remains continuously closed. In a modification, Figs. 7-10 (not shown), a second cam co-operating with a simple on-off switch is fitted on the spindle 10 to provide double-pole isolation in the off " position. In a further modification, Fig. 11 (not shown), a second cam on the spindle 10 closes a switch in the " full " position to energize a second heating element of the hot-plate.