GB2199613A

GB2199613A - Safety belt fastener

Info

Publication number: GB2199613A
Application number: GB08730082A
Authority: GB
Inventors: Lothar Schimpf
Original assignee: DOEBELNER BESCHLAEGE METALL
Current assignee: DOEBELNER BESCHLAEGE METALL
Priority date: 1986-12-29
Filing date: 1987-12-23
Publication date: 1988-07-13
Anticipated expiration: 2007-12-23
Also published as: HUT45880A; DE3743336A1; DE3743336C2; GB2199613B; YU226787A; GB8730082D0; SE8705167D0; FR2608982A1; SE8705167L; HU197507B

Description

SAFETY BELT FASTENER The present invention relates to a safety belt fastener, especially for a vehicle safety belt.

In DD-PS 239 520 there is disclosed a fastener with a locking body consisting of a stamped sheetmetal part, in which an areal locking effect is achieved with minimum opening travel due to the special outline and bearing of the locking body.

Manufacture of this locking body and the lock plate requires increased production effort due to the functionally necessary, precise outline.

Also known are belt fasteners with locking bodies constructed as pivot levers (EP 083752), rockers (DE-OS 2904 420) or stampedsheet- metal parts (EP 107 516). It is disadvantageous in these constructions that they require either closing tongues with an open outline, special mounting elements at the lock plate or a high surface quality.

Locking bodies with areal locking effect and thereby more favourable area pressure require a large opening travel of the locking body They have a tendency to cant, which requires greater opening forces.

Although locking bodies with edgewise locking effect compensate for the above-named disadvantages, the high area pressure requires a very high surface quality of the edges at the locking body and the tongue, which necessitates increased cost There is thus a need for a fastener with a simple outline and bearing of the locking body, an areal force reception, a short travel of the sliding edge during opening, and an easy actuation.

According to the present invention there is provided a safety belt fastener for a tongue with an opening therein, the fastener comprising two plates defining a passage therebetween for reception of such tongue, a locking element pivotable under spring force, on insertion of the tongue into the passage, through an aperture in a first one of the plates and into a locking position in which it extends through the passage and into an aperture in the second one of the plates and engages in the opening of the tongue to lock the tongue in the passage, a release lever which has a holding portion so engageable in the aperture in the second plate when the locking element is in its locking position as to hold the locking element in that position and which is pivotable to move the holding portion out of the aperture in the second plate to permit movement of the locking element out of the locking position, and a resiliently biassed ejector element to eject the tongue from the passage on movement of the locking element out of the locking position and to block movement of the locking element back into the locking position.

In a preferred embodiment, the fastener comprises two plates between which a tongue is insertable against the force of a resilient ejector, the tongue being provided with a rectangular passage opening and being lockable between the plates by a T-shaped locking element.

The locking element is pivotable by means of spring force as well as the tongue and in the open state of the fastener is disposed above the ejector and in the aperture of the upper plate. A lever is actuable in direction of introduction of the tongue to cancel the locking of the tongue and has a web engageable in the aperture of the lower plate and pivotable out of this, wherein the forward surface of the web in direction of introduction of the tongue engages forcelockingly in the recess. The locking element in its locking position engages in the aperture of the lower plate behind the web of the lever in direction of introduction. Consequently, force absorption over an area and a small travel for the unlocking with little friction is achieved by means of only one sliding edge.

Preferably, the pivot centre of the lever is disposed in the forward bearing plane of the web of the lever and is arranged laterally in the aperture in the lower plate. A simple upper plate and a planar locking element may be achieved when the spring force is provided by a tilting spring directed to erecting the locking element and disposed out from the upper plate against the locking element. For preference, lateral closing springs are provided and have an outline effecting detenting on insertion of the tongue. Advantageously, a shaped leaf spring forms the tilting spring and the closing springs. Guidance of the closing springs can be provided in recesses at a T-shaped outline of the locking element.

To facilitate return pivot movement of the locking element a projection at an actuating member, for example a push button, for the lever can be provided for holding down the tilting spring in the actuated setting.

In another embodiment, a compression spring is arranged with one end thereof plugged onto a spigot, which is arranged on the locking element and in locked state of the fastener extends nearly perpendicularly to the plates, and its other end engaging a support plate on a retaining web parallel to the plates. Control of the locking element by means of the compression spring and a bevelled rear side at a step of the ejector may enable an optimum course of movement of the locking element during opening and closing. The course of movement of the locking body may be enhanced if the web of the lever has an outward curvature so that the spring force can guide the locking element unhindered, since this no longer touches the web after it has been released by the lever.

Embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a longitudinal sectional view of a first fastener embodying the invention, showing the fastener in unlocked state; Fig. 2 is a view similar to Fig. 1, showing the fastener in locked state; Fig. 3 is a plan view of the fastener, with removed upper half and push button; Fig. 4 is a sectional view of a front part of the fastener, showing an opening lever thereof in an initial setting; Fig. 5 is a view similar to Fig. 4, but showing the lever during opening of the fastener; Fig. 6 is a view of the opening lever; Fig. 7 is a view of a locking element of the fastener; Fig. 8 is a view of an upper lock plate of the fastener; Fig. 9 is a view of a lower lock plate of the fastener;; Fig. 10 is a longitudinal sectional view of a second fastener embodying the invention, showing the fastener in an unlocked state; Fig. 11 is a view similar to Fig. 10, but showing the fastener in a locked state; Fig. 12 is a side elevation of an opening lever of the fastener of Fig. 10; Fig. 13 is a view of a locking body of the fastener of Fig. 10; Fig. 14 is a view of an upper lock plate of the fastener of Fig. 10; and Fig. 15 is a view of a lower lock plate of the fastener of Fig. 10.

Referring now to the drawings, there is shown in Figs. 1 to 9 a safety belt fastener in which the operative parts are housed in a housing consisting of an upper housing part 1 and a lower housing part 2. An upper stamped lock plate 3 and a lower lock plate 4 are arranged in the housing and connected by means of a rivet 14, which at the same time secures the fastener to a connecting element 15 connected to, for example, a vehicle floor, the element 15 being received between the plates 3 and 4.

A planar locking element 5, constructed substantially in T-shape, is freely mounted in an aperture in the upper plate 3, lateral guidance being provided by the stamped shape of the plate 3,and is biassed by means of a tilting spring arm 6.1.1 of a control spring 6 (Fig. 1) or by means of a compression spring 6.2 (Fig. 10) in the direction of the plate 3 so as to rest at an edge 3.1.

An ejector 7 is arranged in the housing and urged by a spring 8 to lie under the locking element 5, the forward edge 7.1 of the ejector forming the second bearing point of the element 5.

An opening lever 12 has a stamped web 12.1 disposed at the forward edge of an aperture 4.1 in the lower plate 4 and an upper portion lying against circularly arcuate segments 10.1 of a push-button 10. The push-button is biassed by means of springs 13 into a rest position.

The lever 12 is arranged so that operation of the fastener for release of an associated belt tongue 9 is possible even if the housing has been destroyed. The push button 10 includes a step 10.1 which on opening of the fastener lowers the spring 6.1.1 and thereby facilitates return of the locking element 5 into its initial position after removal of the tongue 9 (Fig. 4).

During the locking of the fastener, the tongue 9 presses back the ejector 7 and stresses the spring 8. Due to the force of the spring 6.1.1, the locking element 5 is erected (locking position) while turning about the edge 3.1 and subsequently pivots into an opening in the tongue 9. On complete insertion of the tongue 9, the locking element 5, while extending through the tongue 9 and guided at upper recesses 5.1 thereof by spring arms 6.1.2, engages behind the stamped web 12.1 of the lever 12 and in the aperture 4.1 in the plate 4.

On loading of the fastener, the tension loading of the tongue 9 is taken up by way of the locking element 5 and transmitted directly to the upper plate 3 and indirectly to the lower plate 4 with interposition of the web 12.1 of the lever 12.

During opening of the fastener, the lever 12 pivots by its web 12.1 about its rotational centre and the web 12.1 moves out of the range of engagement, while sliding by its edge at the locking element 5. The tongue 9 is ejected by the ejector 7 while the locking element 5 pivots about the edge 3.1 of the plate 3 until in the position illustrated in Fig. 1.

In the embodiment of Figs. 10 to 15, the afore-described manner of movement of the locking element 5 is realised by an arrangement in which, in place of the shaped flat spring 6.1, there is provided the compression spring 6.2, which is held at one end by a spigot 5.2 on the locking element 5 and at the other end by a retaining web 11.1 of a metal support plate 11 fastened by the rivet 14, the web 11.1 extending parallel to the plates 3 and 4.

In this embodiment, the ejector 7 possesses a step ramp 7.2 which imparts to the spring 6.2 an impulse to initiate tilting of the element 5 into the locking position in which it extends through the opening in the tongue 3.

Claims

1. A safety belt fastener for a tongue with an opening therein, the fastener comprising two plates defining a passage therebetween for reception of such tongue, a locking element pivotable under spring force, on insertion of the tongue into the passage, through an aperture in a first one of the plates and into a locking position in which it extends through the passage and into an aperture in the second one of the plates and engages in the opening of the tongue to lock the tongue in the passage, a release lever which has a holding portion so engageable in the aperture in the second plate when the locking element is in its locking position as to hold the locking element in that position and which is pivotable to move the holding portion out of the aperture in the second plate to permit movement of the locking element out of the locking position, and a resiliently biassed ejector element to eject the tongue from the passage on movement of the locking element out of the locking position and to block movement of the locking element back into the locking position.

2. A fastener as claimed in claim 1, wherein the lever is pivotably mounted laterally of the aperture in the second plate and is pivotable about an axis disposed in a forward bearing plane of the holding portion.

3. A fastener as claimed in either claim 1 or claim 2, wherein said spring force is provided by a spring extending over the first one of the plates and arranged to bias the locking element towards its locking position.

4. A fastener as claimed in any one of the preceding claims, comprising resilient detent means to detent the locking element in its locking position.

5. A fastener as claimed in claim 4 when appended to claim 3, wherein the spring and the resilient detent means are provided by respective portions of a single leaf spring.

6. A fastener as claimed in any one of the preceding claims, wherein the locking element is substantially T-shaped.

7. A fastener as claimed in claim 6 when appended to claim 4, wherein the locking element is provided in the crossbar of the T-shape with guide recesses for the detent means.

8. A fastener as claimed in claim 3, comprising an actuating member actuable to pivot the lever, the press member having a projection engageable with the spring to press the spring towards the first plate.

9. A fastener as claimed in claim 1, wherein the spring force is provided by a compression spring arranged with one end thereof engaging a spigot on the locking element and the other end thereof engaging a retaining member extending substantially parallelly to the plates.

10. A fastener as claimed in claim 9. wherein the ejector element is provided with a step defined by a ramp surface arranged to act on the spring to initiate pivoting of the locking element into the locking position.

11. A safety belt fastener substantially as hereinhefore described with reference to Figs. 1 to 9 of the accompanying drawings.

12. A safety belt fastener substantially as hereinbefore described with reference to Figs. 10 to 15 of the accompanying drawings.