GB779194A - Improvements relating to impact detectors - Google Patents

Abstract

779,194. Impact detectors. TILTMAN LANGLEY, Ltd. May 31, 1955 [March 1, 1954], No. 5968/54. Class 106 (3). A mechanism for indicating when a given acceleration of a body has been exceeded comprises a mass movable relative to the body in the direction of the acceleration and an overcentre biasing mechanism arranged to urge the mass initially in this direction and to trip when the given acceleration is exceeded. As shown, the movable mass is constituted by one fixed mass 17, Fig. 2, at one end of an arm 15 pivoted at 16, and a second mass 18, 19 adjustable in position on the arm on the other side of its pivot. By varying the position of the mass 18, 19 the mechanism may be set for differing given accelerations. The initial position of the masses may be varied by an adjustable stop 21, 22. The over-centre biasing mechanism comprises a flexible leaf spring with a central leaf 5 secured in tension to a block 3 and two outer leaves 10 bowed in compression in engagement with a rigid member 8 secured to the block, the free ends of the leaves being joined together in a contact 12 abutting a depending portion 14 of the arm 15 and normally urging the portion 14 upwards, a limiting stop 24, Fig. 3, being provided. When the given acceleration is exceeded the spring system trips into the position shown in Fig. 3 and this occurrence may be determined by visual inspection or by the making of an electrical circuit between the contact 12 and an upturned portion 13 of the base 1. The electrical circuit may include solenoid means operating a counting or resetting mechanism. The overcentre biasing mechanism may be reinforced by magnetic means on the arm 14 and on the free ends of the spring adjacent the contact 12, one of such means being variable in position to vary the magnetic effect. Specification 419,917, [Group XXXVII], is referred to in the Provisional Specification.