| 摘要 |
774,219. Snap-action springs. RHEOSTATIC CO., Ltd. Oct. 28, 1954, No. 31143/54. Class 108(3). [Also in Groups XXIX and XXXVII] A snap-action device comprises a sheet or strip A of metal, formed with corrugations 1, which are partially flattened near opposite edges X Y of the sheet. In Fig. 5, the strip A carries contacts 9, 10 which co-act alternately with contacts directly below on a base B. The centre point of the strip A between the contacts 9, 10 is held in contact with a support point on the base B by a spring tongue 14. The corner D of the strip A is held to the base B, and it is acted on by a stop screw 15. The actuating pressure is applied at any point 16, between the screw 15 and the corner of the strip A opposite to the corner D. The strip A in this construction, is self-returning after removal of the actuating pressure. The latter may be derived manually, from a pressure-operated bellows or from a heat-responsive device. The snap action may be initiated by a twisting action of the strip or sheet. The device may be used to operate a gas control valve (see Group XXIX). |
