| 摘要 |
<p>An inertia-dependant switching device in which a roller element, preferably a ball, is accommodated in a concave seat for radial movement into contact with a switch member such as an electrical contact or a plunger. The seat has an inner portion in which the ball is mounted when the switch is subject to a steady force acting along a first axis extending through the centres of the ball and the inner portion of the seat, and has an outer portion on to which the ball is able to roll as a result of a predetermined change in the force acting on the ball. The inclination to the first axis of the surface of the outer portion is greater than the inclination of the surface of the inner portion and both portions are preferably formed as surfaces of revolution, such as frustra of cones having different opex angles, which meet at a circular edge. When the force urging the ball to roll radially from its rest position increases sufficiently to cause the ball to roll over the edge between the inner and outer portions of the seat, continued rolling movement is in a direction more closely aligned with the force and so the ball moves more rapidly into contact with the switch member. Where the switch member is a plunger, it may be used to release stored energy in a trigger mechanism for operation of a device requiring greater input energy than the energy supplied to the plunger by the seismic ball.</p> |
