GB1146602A - Retractable safety belts - Google Patents

Abstract

1,146,602. Safety harness. R. G. BOARD and N. H. SHAPIRO. 1 April, 1966 [1 April, 1965; 16 June, 1965], No. 14425/66. Heading A3V. [Also in Division E2] A retractable seat belt comprises a spring loaded reel 24 and a belt clamping arrangement actuated by a movable clamp plate 40 over which the strap 22 is trained. As shown the strap is fully retracted leaving a slack portion leading to a tongue 14 of buckle (12, Fig. 1) and the plate 40, which has pivot pins 44 engaged in slots 46 in side plates 34 of the reel housing, falls downwards under the influence of gravity. When the strap is pulled the clamp plate rotates about the pins 44 in a clockwise direction until a flattened portion 48 engages stops 50 (see Fig. 3), after which the strap slides over the plate 40 as it is withdrawn against the tension of a spring 36. After the belt user has fastened the strap slight return motion of the strap allows the plate 40, under the influence of the strap tension on the upper edge of the plate, to rotate slightly in an anticlockwise direction away from the stops 50 (see Fig. 4) then move up the slots 46 until the pins 44 enter the radial portion of these slots and move to the end of the radial portion nearest to the reel, the lower end of the plate 40 then being clear of the stops 50 (see Fig. 5). In this position of the plate if any attempt is made to further withdraw the strap 22 the plate 40 rotates in a clockwise direction until the strap is clamped between the plate 40 and a fixed clamp part 42, preventing further extension. When the belt is unfastened the plate 40 rotates slightly anticlockwise to allow the strap to be retracted and then it falls to the position shown in Fig. 1. In another embodiment (Figs. 9 to 13) a pusher member (58) and an enlargement (64) on the plate may contact the wound-up strap or the reel flanges to aid movement of the pins in the slots in the side plates. In another embodiment (Figs. 14 to 17) a pusher member 58<SP>1</SP> is concentric with the pivot pins of the plate. In other embodiments (not shown) a channel may be provided in the movable clamp plate to guide the strap or the fixed stops may be replaced by stops on the movable clamp plate which project into windows in the side plates 34. The shape and disposition of the clamp plate in each embodiment prevents increments of slack created in the strap during normal use from being taken up, the upper and lower edges of the clamp plate indenting the strap as the plate pivots between the Fig. 5 (unclamped) and Fig. 6 (clamped) positions without the strap moving relative to the surface of the plate. Only after the plate has pivoted to the Fig. 5 position will further relaxation of tension in the strap cause slack to be taken up.