GB1253107A - - Google Patents

Abstract

1,253,107. Inertia switches. EATON YALE & TOWNE Inc. 30 July, 1969 [20 Aug., 1968], No. 38174/69. Heading H1N. [Also in Division G1] A switch for actuating vehicle safety apparatus in a collision comprises a housing, a mass movably mounted in the housing, a plurality of resilient contact fingers abutting the mass and yieldably restraining movement of the mass from an initial position to an actuated position under normal road conditions, but allowing such movement upon the occurrence of a collision, whereupon some of said contact fingers engage a fixed contact means which is substantially uniformly spaced from the contact fingers in their normal condition. As shown in Fig. 2 a movable mass 66 is in the form of an anhulus surrounding a circular array of resilient contact fingers 72, which normally restrain movement of the mass 66 but under impact are deflected to engage a rigid central contact member 84. The housing 80 is cylindrical but the chamber 92, wherein mass 66 is accommodated, has an insert 100 providing walls 96, 98 which limit movement of the mass 66 to directions lying within an angle of about 120 degrees (Figs. 3 and 4, not shown). This insert 100 may be omitted to allow actuation of the contacts by movement of the mass 66 in any direction, but the member 100 is preferably provided of energy-absorbing material to damp normal vibrations of mass 66. In a second embodiment the movable mass comprises a disc 66a (Fig. 8) with a substantially semicircular array of contact fingers 72a engaging its periphery to hold it against energy-absorbing stop-walls 96a, 98a (Fig. 7, not shown). On impact, the mass 66a moves to urge certain fingers 72a into contact with a fixed contact ring 84a, as shown in Fig. 8. Owing to the arrangement of the fingers 72a a greater number are deflected in a "headon" impact than in a sideways collision and this compensates for greater absorption of energy by deformation of the vehicle in the latter case. Further compensation may be provided by bending some fingers 72a so that they apply different loading to the mass 66a. A scribe 112 may be carried by the mass 66a to record movements of the mass on a surface 114 marked with a polar grid (Fig. 9, not shown) to show direction and force of impacts.