| 摘要 |
1,135,763. Thermal switches. MORPHYRICHARDS Ltd. 3 Feb., 1966 [13 Feb., 1965], No. 6322/65. Heading H1N. The temperature at which a bimetallic strip switches off an electric toaster is automatically varied in dependence upon the temperature of the strip at the start of each toasting operation by means of a variable coupling between the strip and a switch-operating lever, the coupling being reset each time an operation is initiated. A bi-metallic strip 2 fixed at one end to the frame 1 is connected at its other end to pull a rod 5 to the right as the strip 2 is heated. The rod 5 passes freely through a slot (Fig. 2, not shown) in the upper end of a lever 9 which has a stepped portion 11. Toasting is initiated by depression of a spring-loaded member 6, mechanically connected to a switch and carriage for the toast (neither shown), until it is held by the latch 7. A member 13, linked to member 6 (Fig. 9, not shown), allows rod 5 to fall to the bottom of the slot (shown by a broken line). At a temperature predetermined by an adjustable cam 10 the nut 12 engages step 11 on lever 9 to tilt latch 7 and release member 6 to terminate the toasting, while member 13 lifts the rod 5 to the position shown. If a second operation is started while the toaster is still hot the rod 5 will be more to the right and nut 12 will rest on top of step 11 (as in Fig. 7, not shown), thus necessitating a higher temperature of strip 2 before the nut moves lever 9 to release member 6. The stepped portion 11 may consist of several steps in echelon. |
