| 摘要 |
<p>When the twist grip is rotated, the member as a disc, is caused to rotate. Each raised flange around the circumference is a contact. A second member near the circumference is such that it can be struck by each flange in turn on rotation of the disc. The second member is a hollow cone, connected to a sounding board at the external surface of the alarm, which board vibrates, when the outer surface of the cone is struck by a flange. The visual alarm device comprises a flint biased against an abrasive surface on the disc, such that rotation of the disc causes visible scintillations between the flint and abrasive surface. The switch in the electric bulb power circuit is operable by contact with each flange of the disc, such that when each flange contact the switch in turn the bulb flashes. The power switch includes two relatively movable contacts, being made 'on' successively by movement of one of the contacts under the impressed force of each flange, towards the second contact.</p> |
