GB1005301A - Improvements in or relating to control devices for safety harnesses - Google Patents

Abstract

1,005,301. Vehicle safety harness. IRVING AIR CHUTE OF GREAT BRITAIN Ltd. Dec. 30, 1963 [March 11, 1963; Aug. 21, 1963], Nos. 33161/63 and 33162/63. Heading A3V. A device for controlling means for locking a vehicle safety harness against withdrawal comprises a ball carried on a dished surface and a control member which overlies the ball in its position of rest at the lowest point of dished surface, having a portion located so as to be engaged by the ball and moved to a position in which it actuates the locking means when the ball is displaced from its position of rest on acceleration or deceleration of the vehicle beyound a pre-determined value. The control member may be freely suspended at its centre of gravity and tiltable in any direction. Preferably though it is pivotable about a single axis as in Fig. 1 in which displacement of a ball 12 pivots a lever 14 rigid with a pivoted rocker 6 against the action of a spring 7 causing a roller 8 on the end of the rocker to abut a wedge 9 and wedge the harness strap 10 against a wall 11 of the housing of the device. Alternatively pivoting of the rocker may cause electrical actuation of a snubbing device. To prevent jamming or spinning of the ball it is preferred that the said portion of the control member engages the ball below the ball's topmost point as for instance in the embodiment shown in Figs. 4 and 6 in which the said portion of the plate 23 is an aperture 24. The plate is pivoted in the housing about a shaft 21 and includes a curved portion 27 which rests on an adjustable screw 25 to hold the plate 23 level when the ball 18 is in its position of rest. On displacement of the ball it pivots the plate so that the edge of the portion 27 engages a stud 28 rotating the shaft 22 to which the stud is secured and thus causing a pawl 34 also carried by the shaft 22 to engage and lock a ratchet wheel 33 secured to a spring biased reel 29 on which the harness strap 30 is wound. The aperture is elongated and may be so arranged, in this embodiment displaced from a position symmetrically above the ball towards the shaft 21, that the value of deceleration at which locking takes place is lower than the value of acceleration at which locking takes place. This variation can also be achieved by varying the steepness of the dished surface. To avoid operation of the locking means unnecessarily due to irregularities in the road surface the plate 23 may be lightly spring-biased to its level position. Locking will also take place on tilting or overturning of the vehicle or, due simply to inertia of the plate 23, on negative upward acceleration, e.g. when driving at speed over a hump-backed bridge. As alternatives to the aperture 24 in the plate 23 the engaging portion of the plate may be upwardly concave or conical or may comprise a flange or wire ring secured to the underside of the plate. In an alternative embodiment not described in detail movement of the control member closes an electric circuit to apply some unspecified braking action to the harness.