GB784841A - Adjustable temperature control device - Google Patents

Abstract

784,841. Thermal switches. TECHNICON INTERNATIONAL, Ltd. July 8, 1954, No. 19998/54. Class 38 (5). An adjustable temperature-control device comprises member mounted for movement through a wide range for adjustment to a selected position for a predetermined temperature control, and means providing for movement of said member only within a narrow, smaller, range from that position, together with releasable means for securing the member in the selected position and in any position in the narrow range. As applied to a bimetallic switch, the bimetal strip 22 is controlled by a rod 78 bearing on a spring 30 carrying a contact 28. The rod is threaded into a flanged bushing 46 on which is an annular disc 58 surrounding a boss 56 and having a pin 68 connected to a knob 72 which is attached by screw 74 to the rod 78. The device is factory-adjusted by removing the knob 72 and rotating the rod 78 to the required setting, whereupon the disc 58 is rotated until a securing screw 88 is intermediate the ends 64, 66 of a slot 62 in the disc, the screw 88 is tightened and the knob 72 replaced. Subsequent adjustment by the user is effected by loosening the screw 88 and rotating the knob to the required setting and re-clamping by the screw. A pilot light 32 is in series with the contacts which are shunted by a spark-absorbing condenser.