GB2039591A - Improvements in safety belt clasps - Google Patents

Abstract

A vehicle safety belt clasp comprises a pair of lock plates 11 connected by bars 12 to form a frame enclosed by housing shells 18, 19. The locking tongue of the other belt portion is received between plates 11 for releasable engagement by bolt 14. To release the bolt 14 the depressable member 15 is pivoted about point 16 by finger pressure. The return spring 23 is mounted between extensions 17 of bars 12 and engages shoulder 22 formed on member 15, the resilient force acting substantially perpendicularly to the shoulder 22. <IMAGE>

Description

SPECIFICATION Improvements in safety belt clasps The invention relates to clasps for safety belts in vehicles, of the kind comprising a depressable member serving upon depression thereof to urge a locking member into a release position whereby a previously locked locking tongue engaged with the other belt portion is released to undo the belt. The depressable member is mounted pivotably about an axis extending transversely to the push-in direction of the locking tongue and is resiliently urged by a spring to hold the pushbutton in its initial i.e. locking position. A housing preferably divided into two shells encloses the structural parts of the clasp. Such clasps will hereinafter be referred to as of the kind described.

In known clasps of the kind described the depressable member is mounted so that the spring provided to restore it is effective in a direction substantially perpendicular to the operator engaging face. This means that the spring must be supported on a reference face which, viewed from the frame, lies over the member and therefore only an inner face of the housing or of the respective housing shell can serve as the said face. A necessary consequence then is that the depressable member can no longer function as required without a housing or without the associated shell, since the spring no longer has an abutment.However, experience has shown that it happens repeatedly that the clasp housing of more or less flexible plastics which is attached, for example by means of a simple clip connection falls off or is detached and is not fastened correctly again, owing to which the clasp becomes dangerously unsafe.

The object of the invention is therefore to provide a clasp of the kind described which remains safely operational also without a housing or shells.

According to the invention there is provided a clasp for a vehicle safety belt of the kind described in which the depressable member is provided with a shoulder connected substantially at right angles to its main body and substantially in the plane of the pivot of the member, the spring loading the member being arranged on at least one extension of the clasp frame in such a way that said spring acts substantially perpendicularly on the said shoulder.

The basic idea, presented due to the invention, of a depressable member with a bend which provides an engagement face, directed against the longitudinal direction of the lock, for the restoring spring and with a spring mounted correspondingly to be effective in this longitudinal direction results in a substantial improvement of the mode of operation of the clasp. The clasp according to the invention is fully operational in an advantageous way also when housing shells have fallen off or been removed and, moreover, its overall height can be kept compara tivelysmall. If the push-button is mounted pivotably according to one preferred embodiment of the invention between extensions of lock-plate bars, there results a further simplication of the structural form.Since comparatively more space is available in the transverse direction of the clasp, an appropriate liy strong leaf spring may be accommodated as a restoring spring for the depressable member. This spring may simultaneously fulfil also otherfunc- tions.

A preferred embodiment of the invention is described hereinafter with reference to the accompany ing drawings wherein: Figure 1 is a simplified vertical longitudinal section through the centre of a clasp, Figure 2 is a plan view of the frame of the lock with the depressable member and its mounting, Figure 3 is a side view of the mounting of the depressable member on an enlarged scale.

The clasp or lock has a frame 10 which is composed of lock plates 11 and bars 12 keeping same spaced from one another. On the side opposite the bars 12 the lock plates are connected in a way not shown to a cable-shaped anchoring part 13. Guided movably in the transverse direction of the lock plates 11 is a locking member or bolt 14 which serves to lock the lock tongue of the other belt portion not shown. Provided to release the lock bolt 14 and consequently to open the lock is a depressable member in the form of a pushbutton 15 which has at the one end a pivot 16 which is mounted in upper extensions 17 of the bars 12. The above-mentioned structural parts of the lock are enclosed by a plastics housing divided into an upper shell 18 and a lower shell 19.This housing has a front mouth-like opening 20 for the introduction of the lock tongue and an upper window-like opening 21 fortheactuation of the pushbutton 15 by means of finger pressure.

The pushbutton 15 has in the region of the plane of its pivot 16 a shoulder 22 which is attached to the pushbutton approximately at right angles thereto, so that the pushbutton 15 has a substantially L-shaped longitudinal section. The outer faces of the shoulder 22 point, depending on the button position, more or less exactly in the direction of movement of the lock tongue not shown, that is in the direction of extension of the lock plates 11. In the embodiment illustrated the outer face of the shoulder 22 directed towards the push-in opening 20 of the housing 18, 19 is loaded by a leaf spring 23 whose design is to be derived from Figure 2.The leaf spring 23 projects in the centre towards the shoulder 22 where it has a small-area pressure region 24 and extends from the centre outwardly to the sides in a curve around the extensions 17, namely in such a way that it partly closes the bearing points of the pushbutton 15 which are constructed with a special shaping, due to which the effect is achieved that the pivot 16 cannot slide out of the bearing in the depressed position of the pushbutton. The leaf spring 23 thus fulfils several purposes. Moreover, it holds itself against the structural parts 17,22 owing to its shape and initial tension, whereby it is fixed in a vertical direction by respective recesses of the extensions 17. Such a recess is to be seen in Figure 3.

As may be concluded at once especially from Figure 1, the action of the leaf spring 23 on the shoulder 22 of the pushbutton 15 is in no way prejudiced if the upper housing cap 18 has fallen off or been removed for any reason whatever. Apart from this advantage, there results due to the arrangement of the pivot 16 of the pushbutton 15 an improved leverage on the lock bolt on the other side of the lock bolt 14, looking from the finger pressure region in the window 21, and consequently an easier and quicker opening of the lock. However, another construction may also be chosen, for example a rectangular extension of the shoulder 22 in the direction of the push-in opening 20, so that the pushbutton 15 has altogether an approximately Z-shaped profile. In this case, the above-mentioned extension serves to release the lock bolt 14, whereby the lock bolt is not depressed, but lifted (not shown).

The features of the subject of the application which are contained in the preceding description, in the patent claims and in the drawing may be material either individually or in any combinations with one another to the realization of the invention in its various forms of construction.

Claims (8)

1. A vehicle safety belt clasp of the kind described in which the depressable member is provided with a shoulder connected substantially at right angles to its main body and substantially in the plane of the pivot of the member, the spring loading the member being arranged on at least one extension of the clasp frame in such a way that said spring acts substantially perpendicularly on the said shoulder.

2. A clasp according to claim 1, in which the spring acting on the shoulder comprises a leaf spring.

3. A clasp according to claim 2, in which the leaf spring is fastened on both sides of the member to the frame and extends respectively therefrom in a curve to a small-area pressure region projecting in the centre towards the shoulder.

4. A clasp according to claim 1,2, or 3 in which the pivot of the member is arranged on the opposite side of the locking member viewed from the finger pressure region of the depressable member.

5. A clasp according to any of the preceding claims in which the pivot is arranged between two extensions of the frame, said extensions being designed as extensions of locking bars fixing the position of lock plates.

6. A clasp according to claims 3 and 5, in which the leaf spring loops round and grips, behind the extension of the lock-plate bars with its ends on both sides, so that the leaf spring holds itself against the respective lock parts by its spring tension.

7. A clasp according to claim 6, in which the leaf spring grips with its ends over the ends of the pivot and thereby secures them against longitudinal dis placement.

8. A vehicle safety belt clasp substantially as hereinbefore described with reference to the accom panying drawings.