Improvements relating to the prevention of overheating of laundry irons and other electrically heated appliances

摘要

195,605. Simpson, C. A. April 1, 1922, [Convention date]. Electrically-tripped switches.-The supply of current to a heating apparatus such as a laundry iron is controlled by a thermostat and an electromagnetic cut-out operating upon excess current due to short-circuiting the heating element by the thermostat. The cut-out is reset manually, and during the resetting the circuit is opened at a, second switch by the operation of the resetting handle, the circuit being automatically closed at the second switch when the handle is released. Under normal conditions the heating coil 3, Fig. 5, is connected across the supply 2 through the operating coil 6 of a cut-out 4, 5, a switch 13 and a tumbler switch 28. When the temperature of the iron 1 reaches a predetermined value a bi-metallic thermostat 26 closes the contacts 19, 20 to short-circuit the heating coil 3. The increased current in the coil 6, Figs. 2, 3 and 5, causes its plunger 7 to open the switch 4, 5. The switch 4, 5 is reset by a handle 10 which operates a lever 12 connected to a switch 13 by a spring 14 so arranged that when the switch 4, 5 is closed with the handle 10 in its operated position the circuit of the coil 3 is open at the switch 13. When the handle 10 is released a spring 17 returns the lever 12 to its inoperative position and the switch 13 is closed to complete the circuit.