GB2039590A - Buckle for a safety belt system - Google Patents

Abstract

A buckle for a safety belt system has a socket member 20 for receiving a tongue 11, the tongue being latched by a pivoted latch plate 30. Release of the tongue is effected by a spring-urged release member 50 with an arm 54 for engaging the latch member and a nose portion 53 engageable by a sliding push button 60. To prevent inadvertent release of the tongue before depression of the push button is completed, the release member has a portion 55 which overlies and engages the latch member until the release member has been pivoted through a predetermined angle. <IMAGE>

Description

SPECIFICATION Buckle for a safety belt system The invention relates to a buckle for use in a vehicle seat belt system.

Such buckles conventionally comprise a tongue part and a socket part, the socket part comprising a socket for receiving the tongue part therein, a latch member biassed to a latching position in which, when the tongue part is received in the socket, the latch member engages the tongue part to prevent release thereof from the socket, and movable to a release position, in which such release is permitted, and release means manually operable to effect movement of the latch member from the latching to the release position.

For use in vehicle seat belt systems, such a buckle must provide not only a strong connection between its two parts when these are latched together but also security against inadvertent release of the tongue part when there is partial operation of the release member.

The present invention accordingly provides a buckle for use in a seat belt system, the buckle having a tongue part and a socket part, the socket part comprising a socket for receiving the tongue part therein, a latch member movable between a latching position, in which, when the tongue part is received in the socket, the latch member engages the tongue part to prevent release thereof from the socket, and a release position, in which such release is permitted, spring means biassing the latch mem bertothe latching position, and release means manually operable to effect movement of the latch member from the latching to the release position, the latch member and release means cooperating to restrain the latch member against such movement during an initial part of the operation of the release means.

The release means can thus comprise a release member having a portion positioned to act on the latch member to cause movement thereof to the release position, and a further portion arranged to limit such latch member movement during the initial part of the release movement of the latch member.

The spring bias can be applied to either or both of the latch member and the release member.

The engagement between the release member and the latch member may thus be such that a portion of one member is received within a recess of the other, so that the relative movement of the members is limited in either direction. In one convenient construction, the latch member has a release portion engageable by a release lever on pivotation thereof so as to shift the latch member out of latching engagement, the lever having a projection overlying the release portion so as to limit movement of the release portion to the release position because of forces acting on the latch member, until a predetermined position ofthe release lever has been reached.

The invention will be seen to provide for release of the buckle only after a predetermined movement of the release means so that unwanted separation of the buckle parts due to separating forces is resisted even though partial operation of the release means may have inadvertently occurred.

By way of illustration, the invention is further described below with reference to the accompanying drawings, in which: Figure lisa front view of a tongue member comprising a first part of a two-part buckle embodying the invention; Figure 2 is a sectional side view of a socket member comprising the second part of the buckle; Figure 3 is a plan view of a channel member forming a frame of the second part of the buckle; Figure 4 is a plan view of a lock plate received in the frame; Figures 5A and 5B are respectively plan and sectional side views of a lock plate spring acting between the frame; Figure 6 is a front view of a lever member for acting on the lock plate;; Figures 7A and 7B are sectional side views of the channel member with the lock plate and the lever member in place therein, the lock plate and lever member being in an intermediate position in Figure 7A and in a release position in Figure 7B; and Figures 8A and 8B are respectively end and plan views of an ejector member for facilitating or effecting release of the tongue member from the socket member.

The illustrated buckle has as a first part a tongue member 10 (Figure 1) comprising a flat metal plate with a generally rectangular tongue 11 for reception in a socket provided in a second buckle part, constituted by a socket member 20. The tongue 11 has a latching edge formed by a central generally rectangular aperture 16. Extending outwardly from the socket when the tongue 11 is received therein, the tongue member has a connector portion 12 for connection into a seat belt system, which can be of any desired configuration. The connector portion 12 is apertured at 14to receive a belt, and is encased in plastics material 15 to reduce wear on the belt.

Figure 2 is a longitudinal sectional view of the socket member 20 taken in a plane perpendicular to the plane of the tongue 11 of the tongue member 10 when received in the socket. In the following description, such words as "upwardly" and "downwardly" refer to the orientation of the socket member as it appears in Figure 2. These expressions are for convenience in description only as the socket member may have any appropriate orientation in use.

Such directional indications as "forwardly" and "rearwardly" refer to the mouth of the socket member as being "forward".

The socket member 20 comprises a metal channel member 21 having a floor portion 22 with opposed upwardly turned side walls 24 which have portions 25 turned toward each other to overlie the floor portion. The floor portion and side walls provide the socket for reception of the tongue 11. The side walls 24 have transversely aligned generally sector shaped openings 26 towards the mouth of the socket for pivotably receiving a latch plate 30.

The latch plate 30 is a metal pressing having side portions 31 received in the apertures 26, and a central aperture which defines the rear part of a latch portion 32 which is deformed downwardly in the rearward direction. The latch plate 30 tapers rearwardly from the aperture to form a release portion 34 which is also bent downwardly in the rearward direction.

A latch plate spring 40 acts on the latch plate 30 to urge this into its latching position shown in Figure 2 in which the latching portion 32 engages the channel member floor portion 22. The spring 40 has a mounting portion 41 from the side edges of which the limbs of a generally U-shaped spring portion 42 extend forwardly. The forward end of the U-shaped portion 42 has a forward lip 44 at which it engages the upper surface of the latch plate release portion 34. Within the U-shaped portion 42, the mounting portion 41 has two spaced forwardly projecting spring fingers 45 for a purpose described below. The floor portion 22 of the channel member 21 has a tapering rearwardly extending, connector portion 48, and the mounting portion 41 is secured to overlie this connector portion by a rivet 46 extending through apertures in the mounting portion and the connector portion.

The components of the buckle so far described permit the tongue 11 to be latched within the socket as follows. The tongue 11 of the tongue member 10 is pushed inwardly over the floor portion 22 of the channel member 21 and in so doing engages the latch portion 32 of the latch plate 30 and causes this to pivot upwardly against the spring 40. The side walls 25 of the channel member have inwardly struck portions 65 under which the tongue 11 slides during insertion. When the tongue 11 has advanced far enough along the floor portion, the latch portion 32 of the latch plate enters the aperture 16 in the tongue and engages the rearward edge of this aperture and the floor portion under the spring 40.In this position, any force tending to withdraw the tongue member 10 from the channel member 21 is applied by the tongue 11 to the latch portion 32 and by way of the latch plate to the side walls 24 of the channel member.

The rivet 46 also extends through a ferrule 28 at one end of a short end wire assembly 27 for connecting the socket member 20 to an anchorage within a vehicle. The assembly 27 advantageously includes a so-called "dead" wire which has no resilience and can consequently be made to assume any desired shape to facilitate positioning of the socket member where required but a resilient wire can be employed instead. At the end of the assembly 27 remote from the ferrule 28, an apertured mounting bracket 29 is provided for securement to the anchorage.

To permit release of the tongue 11 from the channel member 21, release means is provided for pivoting the latch plate 30 to raise the latch portion 32 up from the floor portion of the channel member and so out of engagement with the tongue 11. The release means comprises a release member 50 having a plate-like lever portion from either side of which extends a shaft portion 51 journalled in bearings formed in the floor portion of the channel member by two laterally spaced opposed pairs of upstrucktongues 63. The shaft portions 51 are retained in engagement with the end faces of the tongues 63 by the fingers 45 of the spring 40. The lever portion has a generally upwardly extending arm 52 formed with a forwardly facing nose 53 at its upper end, a generally forwardly extending lower arm 54, and a locking projection 55 between them.In the latching position, the upper side of the arm 54 underlies but is spaced from the underside of the latch plate release portion 34, and the locking projection 55 overlies and engages the upper surface of the release portion.

Release pressure is applied manually to the nose 53 of the lever arm 52 by means of an operating member 60 which is slidably guided by the channel member 21.

The operating member 60 comprises a stem portion 61 which engages with the overturned wall portions 25 of the channel member 21 to be guided for longitudinal sliding. At the forward end of the stem portion, a transverse plate portion 62 protrudes outwardly from the channel member and carries a suitable legend, for example the word "Press".

Protruding from each side of the stem portion 61 are a pair of projections. The overturned portions 25 of the channel member side walls 24 each have an upwardly struck tongue 23 over which the inner projections are pushed during assembly. The projection co-operates with the tongues 23 to limit the sliding movement of the operating member.

A spring 66 has a coil portion received around a thickened shaft portion 68 of the lever member 50, a lower limb extending from the coil portion to underlie the floor portion of the channel member 21, and an upper limb extending from the coil portion generally upwardly with its free end extending across the rear face of the arm 52 of the lever member. The spring tension tends to bring the two spring limbs together to cause clockwise rotation of the lever member so that the nose 53 engages the rear end of the release member 61 and the locking projection 55 engages the upper face of the latch plate release portion 34.

The tongue 11 is released from the socket member 20 by manual pressure on the operating member 60 to cause this to slide into the socket member. The inner end of the stem 61 then acts on the nose 53 of the release member 50 to turn this against the action of the spring 66, so that the lower arm 54 engages and lifts the release portion 34. The latch plate 30 thus pivots against the latch plate spring 40.

The position after an initial depression of the operating member 60 is shown in Figure 7A. The inner end of the release portion 34 has moved along the upper surface of the lower arm 54 and the locking projection 55 overlies but is spaced from the release portion. Pivotation of the latch plate 30 sufficient to disengage the latch portion 32 from the tongue 11, due to any force that acts on the latch plate only, is prevented. This situation is maintained until the release member 50 has pivoted through about 20 , to the position shown in Figure 7B. The latch plate 30 is then free to pivot further, but release of the tongue 11 from the socket has now been effected in any event. The projection 55 thus acts as a means to prevent inadvertent or premature release of the tongue when the release member is in its inoperative position or is only partly depressed.The lever spring 66 acts through the projection 55 to apply a force that always tends to hold the latch plate 30 in the position in which the tongue 11 is retained in the socket.

To assist withdrawal of the tongue 11, spring loaded ejector means is provided in the socket member. The floor portion 22 of the channel member 21 is provided at each side with a pair of elongate slots 70, joined by a narrow neck near their rear ends to form a rearwardly extending strip 71 and a forwardly extending nose 72. An ejector member 74 comprises a bar 75 which extends transversely of the channel member and which is apertured to be guided on the strips 71 for lengthwise movement.

The member 74 also has a pair of rearwardly extending portions 76 each overlying one of the strips 71. A coiled ejector spring surrounds each strip 71 and associated portion 76, with its inner end receiving the associated nose 72 and its forward end abutting the bar 75.

On insertion of the tongue 11, its leading edge engages the ejector member bar 75 and slides this rearwardly against the ejector springs. The tongue 11 then is latched and the ejector springs remain compressed until the buckle is released. As soon as the latch plate 30 has been pivoted to the release position, the compressed ejector springs urge the ejector member forwardly, pushing the tongue with it, so facilitating or effecting its release from the socket member.

To enclose and protect the buckle mechanism as so far described, and to facilitate handling, a cover is provided which comprises an upper part 80 and a lower part 81 of suitable plastics material, the two parts being assembled around the buckle mechanism and then secured together as by welding. The two cover parts provide at the forward or mouth end of the socket member 20 an aperture for insertion of the tongue, and this extends rearwardly in the upper cover part to accommodate movement of the operating member 60.

It will be evident that the invention can be embodied in various forms of buckle different from the buckle specifically described which can itself be varied within the scope of the invention for example as to the shapes and arrangements of the various components.

Claims (10)

1. A buckle for use in a seat belt system, the buckle having a tongue part and a socket part, the socket part comprising a socket for receiving the tongue part therein, a latch member movable between a latching position, in which, when the tongue part is received in the socket, the latch member engages the tongue part to prevent release thereof from the socket, and a release position, in which such release is permitted, spring means biassing the latch member to the latching position, and release means manually operable to effect movement of the latch member from the latching to the release position, the latch member and release means co-operating to restrain the latch member against such movement during an initial part of the operation of the release means.

2. A buckle as claimed in claim 1 wherein one of the latch member and the release means has a recess and the other has a portion received in the recess during the initial part of the release means operation.

3. A buckle as claimed in claim 1 wherein the release means comprises a release member having a first portion engaging the latch member in the latching position thereof to restrain the latch member against movement to the release position thereof, and a second portion engageable with the latch member on operation of the release means to effect such latch member movement.

4. A buckle as claimed in claim 3 wherein the release member and the latch member are pivotably mounted in the socket part, the first and second portions of the release member comprising jaws between which a release portion of the latch member is received in the latching position thereof.

5. A buckle as claimed in claim 4 wherein the socket part has a socket member providing the socket and a mouth thereof through which the tongue is received into the socket, the latch member is pivoted transversely of the socket member and has a latch portion engageable with the tongue part in the latching position, the release portion being inwardly of the latch portion with respect to the socket mouth, and the release member is pivoted transversely of the socket member inwardly of the release portion.

6. A buckle as claimed in claim 1,2,3 or 4 wherein the release means comprises an operating member manually movable to effect operation of the release means.

7. A buckle as claimed in claim 4wherein an operating member is slidably carried by the socket member for movement in the direction of insertion of the part into the socket, the inner end of the operating member being engageable with the release member to effect pivoting thereof to move the latch member from the latching to the release position.

8. A buckle as claimed in claim 7 wherein the release member comprises a lever pivoted between its ends, one end having the jaws and the other end being engageable by the release member.

9. A buckle as claimed in any preceding claim wherein the release means is spring biassed to the latch member restraining position thereof.

10. A buckle for use in a vehicle seat belt system substantially as herein described with reference to the accompanying drawings.