| 摘要 |
<p>A detector (90) comprises at least two detector devices (95). Each such device includes a magnet (91) which is disposed to execute recriprocating movements in relation to a rest position in a journal (97) or secured to a resilient body (96a). The direction of movement for each magnet is substantially at right angles to the directions of movement of the other magnets. At least one spring means (96, 96a) is provided for each magnet in order temporarily to hold the magnet in its rest position. An electric device (98, 113, 99) is provided for emitting electric signals based on changes in the flow of the magnetic field in the event of movement of each magnet.</p> |
