| 摘要 |
<p>The switch responsive to sudden movements - for example the movement of a wire disturbed by an intruder - comprises a box having lower (1) and upper parts (2). Between them these two parts hold a membrane (3). A further small box (5) holds a smaller membrane (4) on to the lower surface of the lower box. Between the two membranes is an enclosure which only communicates with the atmosphere through an opening restricted by a control screw (11). The upper large membrane is mechanically linked to a shaft to which the sudden movement may be applied. The lower (smaller) membrane carries a moving contact (6) which may touch a fixed contact (7) if the membrane is distorted. Sudden movement of the large membrane produces an increase in pressure which in turn causes the small membrane to move and close the contacts. Slow movement, such as that caused by thermal expansion does not affect the contacts.</p> |
