| 摘要 |
<p>1,018,074. Thermal switches; retractive switches. TEXAS INSTRUMENTS INCORPORATED. June 20, 1962 [June 21, 1961], No. 23807/62. Heading H2B. A safety switch 17 for an electric power tool comprises a manually-operable control switch M and a thermally responsive switch T, and includes a slide 23 movable to operate a switching arm 117 of control switch M with a snapaction and capable of resetting the bimetallic snap-action disc of switch T after the disc has snapped upwards to open the switch contacts upon overload of the power tool. A trigger 38 (Fig. 1, not shown) in a power saw handle moves a pivoted arm when operated to move the slide 23 against a restoring spring and to actuate switch M, the arm 117 of which has spring fingers 119 engaging fixed contacts such as 101, an overcentring spring 121 providing the snapaction. The housing is in two parts 47 and 49 held together by a metal strap 51 with spring finger clips 53 engaging under lugs 55 on part 49. If required manual operation of slide 23 is possible by pressing end 24 thereof.</p> |
