GB2073810A - Improvements in or relating to a buckle - Google Patents

Abstract

In a buckle, for a seat belt, a catch plate 10 having teeth 20, 21 adapted to engage abutment faces 18, 19 on a tongue 15 is pivotally mounted in a channel member 2. A spring biassed ejector 28 moves rearwardly when the tongue 15 is inserted in the buckle, and when the tongue has been moved by such a distance that the abutment faces 18 and 19 are located behind the teeth 20, 21, then a catch stop 36 which retains the catch in an elevated position is engaged by the ejector and moved rearwardly thus permitting the catch plate to drop, under the bias of the spring 9 to the latching position. Thus there is no possibility of the teeth 20 of the latch plate engaging only a small portion of the abutment faces 18, 19. Release is effected by pushing slider 26 causing the rotation of pivoted hooks 22, 23 with the consequent lifting of catch plate 10. <IMAGE>

Description

SPECIFICATION Improvements in or relating to-a buckle This invention relates to a buckle and more particularly to a buckle intended for use with a safety belt or harness such as a seat safety belt or harness as utilised in a vehicle such as a motor car.

Many vehicles are provided with safety belts or harnesses and it is common for the safety belt or harness to include one portion provided with a plate, which plate has a projecting tongue or the like, the tongue being adapted to be inserted into a buckle which securely retains the tongue of the plate so that the safety belt or harness is securely retained in position around an occupant of the vehicle.

Many prior buckles of this type incorporate a catch plate which has a protruding tooth and when the tongue is inserted into the buckle the, catch plate is biassed by a spring so that the tooth engages the top surface of the tongue. When an aperture or similar abutment formed in the tongue is aligned with the tooth, the catch plate pivots downwardly so that the tooth engages either with the aperture or the abutment formed on the tongue.When the catch plate has engaged the tongue in this way the tongue cannot be withdrawn from the buckle, and thus the buckle is provided with a slider or some other corresponding mechanism that can be actuated to move the catch plate to a release position in which the tooth carried by the catch plate is disengaged from the tongue, thus permitting the tongue of the plate readily to be withdrawn from the buckle to permit the occupant of the vehicle to release himself. Buckles of this type are described, for example, in British Patent Specifications No.

1,391,816 and 1,496,342.

It is conceivable that with some prior proposed buckles of this type under certain circumstances the tongue could be inserted into the buckle in such a way that, just as the tooth -of the catch plate moves from the release position towards the locking position an outwardly directed force is applied to the tongue. Under such circumstances it is conceivable that the edge of the tooth of the catch plate will engage only the upper edge of the aperture or abutment formed on the tongue. Thus the tooth will not come into full engagement with the aperture or abutment.If the buckle was in this condition (which can be considered to be a "false" locking position) and if a sudden force were exerted on the seat belt or buckle, for example as a result of an accident involving the vehicle in question, it is possible that the tooth on the catch plate may become disengaged from the aperture or abutment on the tongue, and thus the tongue would not be retained within the buckle, and the person wearing the seat belt or harness would not be restrained. This is clearly a very undesirable situation.

The present invention seeks to provide a buckle in which the above described potential disadvantage of prior proposed buckles is reduced or obviated.

According to this invention there is provided a buckle for safety belt or harness, said buckle comprising a catch plate mounted for movement between a locking position and a release position, the catch plate having means thereon adapted to engage, in the locking position, an aperture or abutment formed on a tongue adapted to be connected to a safety belt or harness or the like, said buckle including means adapted to retain said catch plate in said release position until said tongue has been inserted in said buckle by such a distance that the portion of the aperture or abutment on the tongue to engage with the engaging means on the catch'plate have passed said engaging means on the catch plate.

It is to be appreciated that in operation of such a buckle since the forward edge of the aperture or the abutment means on the tongue have passed the corresponding engagement means on the catch plate before the catch plate is able to move from the release position, when the catch plate moves from the release position to the locking position there is no possibility of the engagement means on the catch only partially engaging the aperture or abutment means on the tongue.

Instead the catch will move to such a position that the catch is in the complete locking position before the aperture or abutment means on the tongue will engage the engagement means on the catch plate. Preferably said retaining means comprise a catch stop constituted by a member having a portion adapted to be located in engagement with the catch plate to retain the catch plate in the release position until the tongue has been inserted into the buckle by said distance, the buckle may include a spring biassed ejector adapted to eject the tongue from the buckle.

Advantageously the catch stop is connected to the ejector by means of a "lost motion" arrangement so that when the tongue has been inserted into the buckle to such an extent the ejector has been moved by a predetermined distance, the catch stop is retracted from its position in which the catch plate is retained in the release position, to permit the catch plate to move the locking position.

Preferably the "lost motion" arrangement is such that when the catch plate is in the locking position the ejector can engage and bias the tongue so that the aperture or abutment on the tongue is brought into firm contact with the corresponding engaging means on the catch plate.

Conveniently the ejector and the catch stop are both slidably mounted within the buckle, and are biassed forwardly towards a mouth of the buckle through which the tongue is inserted into the buckle, the ejector having two opposed inwardly facing abutment surfaces, and the catch stop having a member adapted to be engaged by said abutment surfaces respectively on forward and rearward movement of the ejector.

Advantageously the buckle comprises a channel member, the catch plate being pivotally connected to the channel member, the channel member also supporting a slider member, there being hook-like members adapted to be rotated on the movement of a slider member and adapted, on rotation thereof, to lift the catch plate from the locking position to the release position.

Preferably the channel member comprises a base and two upstanding side walls, the upstanding side walls having slots therein to accommodate tabs formed on the catch plate.

Conveniently the slots include elongate portions and the slider comprises a body formed of plastics material having two downwardly extending arms embracing the exterior of the channel, the downwardly extending arms having inwardly directed ribs or protrusions which engage elongate portions of the slots formed in the outstanding arms defining the channel member.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to one specific embodiment which is illustrated in the accompanying drawings, in which: FIGURE 1 is a partially exploded view of a buckle in accordance with the invention with the outer cover removed; FIGURE 2 is a perspective view of the channel and hook members of the buckle shown in Figure 1; FIGURE 3 is a perspective view of the ejector member of the buckle shown in Figure 1; FIGURE 4 is a perspective view of the ejector member and a cooperating catch stop member of the buckle shown in Figure 1; and FIGURES 5a to 5d are vertical sectional drawings showing various components of the buckle in the positions that they occupy during various successive stages of a complete cycle of operation of the device.

A buckle in accordance with the present invention comprises a channel member 1 made of metal. The channel member has a substantially flat base 2 and two upstanding side walls 3, 4 and thus the channel is of substantially "U" cross section. An aperture 5 is formed in the base of the channel at one end thereof, the aperture being intended to accommodate a bolt or rivet 6 or the like to enable the channel to be connected securely to a portion of a seat belt or a member 7 that can be securely connected to the chassis of a vehicle such as motor car. The bolt or rivet also retains a clamp plate 8 and a spring 9 which serves to bias the catch plate 10, described hereinafter, downwardly.

Two mirror image slots 11, 12 are formed in the two upstanding side walls 3, 4 of the channel 1. The catch plate 10 has tabs 13, 14 at opposite sides thereof, the tabs being accommodated within the slots 11, 12 in the channel member so that the catch plate 10 can execute a pivotal movement. The catch plate is biassed towards the base of the channel by the above mentioned catch spring 9.

A tongue forming part of a plate secured to a part of a seat belt or buckle, is intended to be inserted into the buckle through an open mouth (not shown) at the front of the channel with part of the tongue passing between the lower surface of the catch plate 10 and the upper surface of the base 2 of the channel 1. In this embodiment the tongue is provided with two lateral recesses 16, 17 which define two abutment faces 18, 19 each adapted to engage with a downwardly deflected tooth 20,21 formed on the catch plate 10 when the catch plate 10 has moved pivotally under the bias of the catch spring 9 to a locking position.

Two hook members 22, 23 are provided which are formed of a suitable reinforced plastics material, the hook members having their bases located in appropriately formed recesses 24, 25 defined in the bottom part of the channel so that the hook members can rotate. The upper parts of the hook members are engaged in appropriate recesses formed in a slider member 26 which is mounted for sliding movement axially of the channel. The slider comprises a member formed, for example, of a plastics material, the slider member having an upper portion, and two downwardly extending arms which embrace the exterior of the channel. The downwardly extending arms each carry an inwardly directed rib or protrusion which engages with a longitudinally extending part of the slot 11, 12 formed in the adjacent side wall of the channel.Thus the slider 26 is "snapped" into position on the channel and can then slide axially of the channel. The slider is biassed to a forward position by means of an appropriate spring 27. The arrangement is such that when the slider is pressed to move axially of the channel against the bias of the spring 27, the hook members 22, 23 are caused to rotate, portions of the hook members then engaging portions of the catch plate 10 and lifting the catch plate from the locking position to a release portion thus disengaging the teeth 20, 21 on the catch plate from the abutment faces 18, 19 on the tongue 1 5 so that the tongue 1 5 may be ejected from the buckle.

A spring biassed ejector member 28 is provided within the buckle, which engages the end of the tongue and which provides an outwardly directed biassing force on the tongue at all times whilst the tongue is within the buckle.

The ejector member 28 has a recess 29 at the forwarded edge thereof, the recess being adapted to accommodate snugly the forwardmost part of the tongue 1 5. The ejector member also defines two facing abutment surfaces 30, 31 which face each other across a planarface 32 defined on the top surface of the ejector member 28. The ejector member is slidably mounted within the buckle by engagement of portions of the ejector member with inwardly directed arms 33 formed in the base of the buckle (see Figure 2). The ejector is biassed forwardly by means of a spring 34 that engages a recess formed within the ejector member 28 and also engages a spigot 35 defined in the base of the channel.

A catch stop member 36 is also provided, the catch stop member having two side walls 37, 38 each provided at the lower edge, with an inwardly directed rib 39 that slidingly engages a correspondingly shaped portion of the ejector member 28 so that the catch stop member is slidably mounted on the ejector member 28. The catch stop member includes a transversely extending arm 40 that extends across the said planar face 32 of the ejector member 28. The catch stop member 36 is maintained in position since this transverse arm 40 is located underneath a retaining finger 41 that is formed integrally with the base of the channel, as can be seen most clearly from Figure 2. The catch stop member 36 is biassed forwardly by two springs 42, 43 that are shown most clearly in Figure 1. However, forward motion of the catch stop member 36 is limited.

The catch stop member 36 is adapted to have portions of the side walls 37, 38 thereof located between the catch plate 10 and the base of the channel 2 when the tongue is not in the buckle, so that the catch stop 36 serves to retain the catch plate 10 in such a position that the teeth 20, 21 provided on the catch plate cannot engage the abutment faces 18, 1 9 defined on the tongue 1 5.

The catch stop 10 is, as will now be made clear, connected to the ejector by a "lost motion" arrangement. Consequently the ejector 28 must be moved inwardly by a predetermined distance (which is a distance selected to be sufficient to ensure that the abutment faces 1 8, 1 9 defined on the tongue 15 are moved well past the position occupied by the teeth 20, 21 on the catch plate 10 when the catch plate 10 is in the latching position) before the catch stop member 36 is moved to such a position that the catch plate 10 is released and permitted to move, under the bias of the spring 9, to the latching position.

The function of the ejector 28 and catch stop 36 can be most readily understood if a cycle of operation of the buckle is considered. When the buckle is in its initial condition as shown in Figures 1,4 and 5a, that is to say when the tongue has not been inserted into the buckle and the buckle is ready to receive the tongue, the ejector 28 is in a forwardmost position with a portion of the ejector lying underneath the catch plate 10, and the catch stop 36 is also in a forwardmost position, again with portions 37, 38 of the catch stop being located under the catch plate 10. Thus the catch plate 10 is retained in an elevated position out of the path to be followed by the tongue 1 5. The tongue 15 is then inserted into the buckle.The innermost end of the tongue engages the ejector 28 and drives the ejector 28 rearwardly against the bias of an appropriate spring 34. After the ejector has been driven rearwardly for a predetermined distance the abutment surfaces 30, 31 on the ejector 28 will engage the transverse arm 40 on the catch stop causing the catch stop also to be driven. When the catch stop has been driven for a predetermined distance the portion 37 of the catch stop that was initially located under the catch plate is withdrawn from that position, and the situation immediately before this happens to be shown in Figure 5b. As the catch stop 36 is withdrawn from its initial position, the catch plate 10 pivots to a locking position under the biassing action of the catch spring 9.However, the arrangement is such that, when the catch stop is withdrawn from its initial location underneath the catch plate the abutment surfaces 18, 1 9 on the tongue 1 5 that are to engage the teeth 20, 21 of the catch plate are located forwardly of the teeth. Thus the teeth will fall downwardly into the recesses 1 6, 1 7 and cannot engage the side edge of the abutment faces 18, 1 9. There is not way that a force can be applied to the tongue in such a way that a "false" locking position is obtained, as in the described prior art buckles.

When the catch has moved pivotally to the locking position the tongue is then biassed outwardly by the ejector and its associated spring, thus the tongue is urged to such a position that the abutment faces 18, 1 9 on the tongue are brought into firm contact with the teeth 20, 21 on the catch plate. This is shown in Figure 5c. Thus the tongue is locked securely in position and,, by virtue of the action of the ejector the tongue is prevented from rattling within the buckle.

When the tongue is to be released the slider 26 is moved against the bias of the spring 27 to move the hook shaped members 22, 23 to pivot the catch plate 10 to such a position that the teeth 20, 21 are disengaged from the abutment faces 1 8, 1 9. The ejector 28 will then be able to eject the tongue, the ejector moving to a position where a portion of the ejector 20 is located under the catch plate 10. As the ejector moves to this position, as shown in Figure 5d, after the ejector has moved by a predetermined distance a sloping cam surface 42 on the ejector engages the latch plate and lifts the latch plate during further forward movement of the ejector.Also the second abutment surfaces 30, 31 on the ejector engage the transverse arm of the catch stop causing the catch stop 36 also to move forwardly to such a position that a portion 37 of the catch stop is located under the now fully elevated catch plate 10. Thus the buckle is ready for the next cycle of operation.

It is preferred that there is the above described "lost motion" connection between the ejector and the catch stop so that the ejector can bias the tongue into firm engagement with the catch to minimise rattles, and to ensure that a locking condition exists.

Whilst the invention has been described with reference to one specific embodiment in which teeth on a catch plate engage abutment faces formed in a tongue it is to be noted that the invention is equally applicable to buckles in which the tongue is provided with an aperture in which a single tooth on the catch plate engages with an abutment formed by one side of the aperture.

Many alterations and modifications will suggest themselves to those skilled in the art.

Claims (11)

1. A buckle for safety belt or harness, said buckle comprising a catch plate mounted for movement between a locking position and a release position, the catch plate having means thereon adapted to engage, in the locking position, an aperture or abutment formed on a tongue adapted to be connected to a safety belt or harness or the like, said buckle including means adapted to retain said catch plate in said release position until said tongue has been inserted in said buckle by such a distance that the portion of the aperture or abutment on the tongue to engage with the engaging means on the catch plate has passed said engaging means on the catch plate.

2. A buckle according to claim 1 wherein said retaining means comprise a catch stop constituted by a member having a portion adapted to be located in engagement with the catch plate to retain the catch plate in the release position until the tongue has been inserted into the buckle by said distance.

3. A buckle according to claim 2 wherein the buckle includes a spring biassed ejector adapted to eject the tongue from the buckle.

4. A buckle according to claim 3 wherein the catch stop is connected to the ejector by means of a "lost motion" arrangement so that when the tongue has been inserted into the buckle by said distance and the ejector has been moved by a predetermined distance, the catch stop is retracted from its position in which the catch plate is retained in the release position, to permit the catch plate to move the locking position.

5. A buckle according to claim 4 wherein the "lost motion" arrangement is such that when the catch plate is in the locking position the ejector can engage and bias the tongue so that the aperture or abutment on the tongue is brought into firm contact with the corresponding engaging means on the catch plate.

6. A buckle according to any one of claims 2 to 5 wherein the ejector and the catch stop are both slidably mounted within the buckle, and are biassed forwardly towards a mouth of the buckle through which the tongue is inserted into the buckle, the ejector having two opposed inwardly facing abutment surfaces, and the catch stop having a member adapted to be engaged by said abutment surfaces respectively on forward and rearward movement of the ejector.

7. A buckle according to any one of the preceding claims wherein the buckle comprises a channel member, the catch plate being pivotally connected to the channel member, the channel member also supporting a slider member, there being hook-like members adapted to be rotated on the movement of a slider member and adapted, on rotation thereof, to lift the catch plate from the locking position to the release position.

8. A buckle according to claim 7 wherein the channel member comprises a base and two upstanding side walls, the upstanding side walls having slots therein to accommodate tabs formed on the catch plate.

9. A buckle according to claim 9 wherein the slots including elongate portions and the slider comprises a body formed of plastics material having two downwardly extending arms embracing the exterior of the channel, the downwardly extending arm having inwardly directed ribs or protrusions which engage elongate portions of the slots formed in the outstanding arms defining the channel member.

10. A buckle substantially as herein described with reference to and as shown in the accompanying drawings.

11. Any novel feature or combination of features disclosed herein.