| 摘要 |
<p>939,887. Thermal switches. KING-SEELEY THERMOS CO. Jan. 30, 1962, No. 3406/62. Class 38 (5). [Also in Group XXXV] The controller for an oven 10 comprises a casing 96 in which are housed a number of polymetallic elements all of which are ambient temperature compensated by virtue of their shapes and all of which have heating coils associated therewith. The polymetallic element 36 is of the self-interrupting type and forms a voltage regulator whilst the polymetallic elements 156, 182 co-operate with one another and form a heat regulator for the oven 10. Current passing through a heater coil 174 of the element 156 causes the leg 154 to bend so that a pin 152 attached thereto moves a disc 142 in an anti-clockwise direction. The disc 142, which carries a contact 148, is attached to a spindle 134 journalled in a nylon bearing 118, a pointer 140 being fixed to the spindle 134 outside the housing 96. A bracket 122 which is a push fit on the bearing 118 carries the polymetallic element 182 which itself carries a contact 178. The contacts 178, 148 are in the circuit of the heating current for the element 182 so that incipient opening and closing of the contacts occurs. A second manually adjustable pointer 104 is carried on a spindle 106 journalled in a bracket 100 fixed to the housing 96, the pointer 104 having a part 110 bent at right-angles which co-operates with a slot 112 in the bearing 118. Movement of the pointer 104 thus causes movement of the bearing 118 and hence the bracket 122 whereby the polymetallic element 182 is moved to set the position of the contact 178. All of the thermally operated members are initially settable by means of rack- and-pinion devices.</p> |
