GB1132700A - Retractable safety belt apparatus - Google Patents

Abstract

1,132,700. Locking rotary elements. R. G. BOARD, and N. H. SHAPIRO. 14 Dec., 1965 [14 Dec., 1964], No. 53056/65. Heading F2E. [Also in Division A3] A retractable seat belt assembly comprises a retraction device for the belt, means for preventing extension of the belt and a belt guide supported for movement between a first position, at which the preventing means is inoperative, and a second position at which the preventing means is operative. In one embodiment the belt 22 is wound on a spring retraction reel in a housing clamped to the vehicle. The reel has a ratchet wheel 42 at at least one side and is biased to retract the belt by a helical torsion spring 25. A guide for the belt is pivotally mounted in the housing about an axis 46 parallel to the axis of the reel. The guide is U-shaped with side-plates 50 and a cylindrical cross-pin. The belt passes around the pin and urges the plates 50 against stops 54 on the housing during extension of the belt. When the tension in the belt is released the guide pivots and the cross-pin engages the ratchet wheels 42 to prevent further extension. The belt may now only be retracted under the influence of the spring 25. When a sufficient length of belt has been retracted on to the reel the guide is in such a position that the belt may be extended again. The U-shaped guide may have an additional cross-pin near the pivot 46. In a further embodiment, Figs. 4-9 (not shown), the belt guide is U-shaped and is mounted so that its legs (62) move radially of the reel in guides (64). A projection (66) on each leg engages with the guides 64 during extension of the belt but when the tension is relaxed the leg moves through the guide so that its end (68) engages the ratchet wheel. In a third embodiment, Figs. 10-13 (not shown), the U-shaped guide is formed with a bell-crank shaped leg (76), (78) which engages with the ratchet-wheel (72) when the tension in the belt 22 is released. In a fourth embodiment, Figs. 14-17 (not shown), the guide is a shaped plate (86) pivoted about one edge (88) and having a curved opposite edge over which the belt passes. A projection (94) on the plate engages the belt wound on the reel and pins (92) mounted on the ends of the plate engage the ratchet wheel (84). In a final embodiment the guide is U-shaped as in the first embodiment, the arms 100 having an arcuate plate 108 fixed thereto, the plate 108 acts as a brake against the belt on the reel when the tension in the reel is relaxed. The arms 100 have extensions 112 at their opposite ends which pass through to side wall of the housing. To disengage the brake from the reel the arm is pushed into the housing and the groove 116 engaged with the wall. Retraction of the belt is prevented by co-operation of the projection 118 with the joint 112A of the arm. The cooperation is sufficient to prevent retraction but the belt may be further extended. The plate 108 may be arranged to act on side plates of the reel rather than the belt.