GB2110292A - Buckles for vehicle seat belts - Google Patents

Abstract

The vehicle seat belt buckles each have two plate members (12, 14) defining a socket between them for releasably receiving a flat tongue (1). A latch member (24) is movable from latching engagement with the tongue by a push button (31) slidable against a return spring (38) within a cover (30) around the socket, and is held clear of the tongue until this re- enters the socket. The latch member (24) is non-rotationally movable transversely of the direction of movement of the tongue into the socket and guide means are provided in the form of roller 26 supporting the latch member (24) at a position spaced from the socket against forces tending to withdraw the tongue from the socket. <IMAGE>

Description

SPECIFICATION Buckles for vehicle seat belt system The invention relates to a buckle of a kind suitable for use in a vehicle seat belt system and comprising a tongue part and a socket part, the tongue part having a tongue with a latch formation, and the socket part having a socket within which the tongue can be releasably latched by a latch mechanism having a latch member engageable with the latch formation.

Buckies of this kind conventionally require the tongue, on insertion into the socket, to engage the latch member to move this out of the path of the tongue to a position from which the latch member returns under spring pressure to latch the tongue in place; the tongue consequently experiences considerable resistance to insertion, and undesirable lateral loading. In some instances therefore the latch members engage the tongue so as to oppose withdrawal with only limited strength. The latch members can in some instances be displayed to release the tongue by inertial forces experienced when the buckle undergoes a sharp deceleration, as during an accident.

The invention accordingly provides a buckle of the kind described in which the latch member is retained in a position which does not substantially obstruct entry of the tongue into the socket when the tongue is absent therefrom. The socket part can thus have catch means arranged to hold the latch member in a non-latching position on withdrawal of the tongue from the socket, the catch means being operable to return the latch member, or to permit the return thereof, to a latching position on re-entry of the tongue to the socket.

Such catch means can act on a slidable push button operatively linked with the latch member and arranged to be released by an ejector moved by the tongue as it enters the socket. The catch means can instead block the latch member against entry into the socket and can then be constituted as a spring urged ejector member which is moved by the tongue to clear the way for the latch member to reach its latching position.

Preferably however an anti-latching member acts between the latch member and the socket and is moved from this anti-latching position by an ejector member after the ejector member has been moved a certain distance by the tongue.

The latch member can be mechanically linked with the push button by a pin and guide slot arrangement.

The invention also provides a buckle of the kind described in which insertion of the tongue into the socket is resisted only by the force of an ejector spring for facilitating removal of the tongue on release of the buckle, the energy needed to move the latch member to the locking position on insertion of the tongue being obtained from the previous release of the tongue from the socket.

The invention also provides a buckle of the kind described having means, for example roller means, spaced from the socket for supporting the latching member externally of the socket against withdrawal forces acting on the tongue.

The invention also provides a buckle of the kind described in which the latch member is held in the latching position thereof by a catch element manually movable from a latch member holding position when the buckle parts are to be separated. The latch member is thereby extremely securely retained in the latching position.

The latch member can be arranged to move to a non-iatching position, on disengagement of the catch element, under a spring bias, and where the latch member is retained in a non-latching position when the tongue is absent from the socket, it can be so retained by this bias. The latch member can then be provided with an ejector portion engageable by the tongue on insertion into the socket to move the latch member to the latching position against the bias, which subsequently acts as an ejector spring causing positive ejection of the tongue when the buckle is released.

The invention thus provides a buckle of the kind described in which the latch member is spring biassed to function also as an ejector member.

The parts of the structure are thereby economically employed.

The latch member can instead be retained in a non-locking position by engagement by the catch element under a spring bias, this engagement being releasable on entry of the tongue into the socket, on which the latch member returns to the latch positions and is firmly held therein by the first mentioned engagement of the catch element.

In a third structurally convenient arrangement, the latch member is held in a non-latching position by a separate ejector member which is arranged to assume a position, in the absence of the tongue from the socket, which blocks the latch member from moving to the latching position, to which it may be movable by the catch member under a spring bias.

The release of the latch mechanism is advantageously effected by means of a release member separate from the latch member but manually operable to effect disengagement of the latch release movement or the catch element from the latch member. The release member can take the form of a push button slidable parallel to the direction of movement of the tongue against a return spring. The release member can be fixedly connected to the catch element and where this is retained out of its holding position when the tongue is absent from the socket, the release member is held in the operated position also. The release member can instead be allowed to return to its inoperative position by providing a suitable lost motion connection between it and the catch element.

The invention is further described below by way of illustration, with reference to the accompanying drawings, in which: Figure 1 is a sectional side view of a first buckle embodying the invention; Figure 2 is a plan view of the tongue part of the buckle of Figure 1; Figure 3 is a sectional front view of the buckle of Figure 1 taken on the line Ill-Ill of Figure 1; Figure 4 is a sectional side view of a second buckle embodying the invention, shown in the absence of the tongue part from the socket part; Figures 5A and 5B are respectively plan and side views of an ejector included in the buckle of Figure 4; Figures 6A and 6B are respectively plan and front views of an anti-latching member of the buckle of Figure 4; Figure 7 is a side view of a lower plate included in the buckle of Figure 4;; Figure 8 is a sectional side view of a third buckle embodying the invention; Figure 9 is a sectional front view of the buckle of Figure 8 taken on the line VIll-VIll of Figure 8; Figure 10 is a sectional side view of a fourth buckle embodying the invention; Figure 11 is a sectional front view of the buckle of Figure 10 taken on the line Xl-Xl of Figure 10; Figure 12 is a sectional side view of a fifth buckle embodying the invention; Figure 1 3 is a sectional front view of the buckle of Figure 8 taken on the line Xlll-Xlll of Figure 12; and Figure 14 is a plan view of an alternative form of tongue part which can be used with suitably modified versions of the socket parts of the buckles illustrated.

In the following description, directional terms such as "inwardly" and "rearwardly" refer to the direction of movement of the tongue part on insertion into the socket part of the buckle. Terms such as "upper" and "lower" refer to the illustrated buckles as they appear in the drawings.

These terms are employed for convenience of description only, as the buckles of the invention can be employed in any orientation, and in seat belt systems of any configuration.

The buckle illustrated in Figures 1 to 3 comprise a tongue part 1 and a socket part 11. As best seen from Figure 2, the tongue part 1 is a flat elongate metal plate having at one end a transverse aperture 2 by which it can be connected to the belt of a vehicle seat belt system.

From this end extends a tongue which tapers to a narrow neck 4 from which it broadens out on either side by means of transverse edges 5 which constitute latch formations by which the tongue can be retained in the socket of the socket part 11.

Finally the tongue part converges to a rounded nose 6.

The socket part 11 comprises a frame consisting of a lower metal plate 12 and an upper metal plate 14 held in spaced parallel relationship to define between them a socket with an open end or mouth 1 5 through which the tongue of the tongue part 1 can be inserted into the socket and withdrawn from it. The upper and lower socket plates are held together by upwardly extending side portions 1 6 of the lower plate 1 2 by which this is keyed to the upper plate 14.The socket plates extend rearwardly from the mouth 1 5 beyond the socket, through double bend portions 1 8 to securement end portions 1 9 where they receive between them a metal bracket 20 which extends further rearwardly to provide a means whereby the socket part 11 can be anchored to a vehicle, as by a bolt, of which the head 21 is shown in Figure 1, extending through an aperture in the bracket 20. The securement end portions of the upper and lower plates 12, 14 are held together by a rivet 22 or other suitable fastening means extending through aligned apertures in them and in the bracket 20. The socket part can be readily modified for securement to a vehicle mounting position by means other than a metal bracket, for example, a "dead" or a resilient cable or a short portion of belt.

Accommodated within the socket part 11 is a latch member or plate 24 guided so as to slide vertically, and thus at right angles to the direction of movement of the tongue into and out of the socket, between the latching position shown and a release position indicated in broken lines. The latch plate 24 is generally rectangular when viewed from the front except for two downwardly extending rectangular latch portions 25 and two lugs 28 extending laterally at the top. In the latching position, the portions 25 extend through an aperture in the upper plate 14 and span across the socket into an aperture in the lower plate 12.

When the tongue is fully inserted into the socket, its edges 5 are positioned inwardly of the latch portions 25, which straddle the neck portion 4 of the tongue. Withdrawal forces acting on the tongue are applied by the edges 5 to the rear faces of the latch portions 25 which are supported, at positions directly adjacent the engagement positions of the edges 5, by abutment against the rearward faces of the apertures in the plates 12, 14 so the withdrawal forces are transferred to the socket part and thus to the vehicle mounting position in a direct and extremely strong manner.

The upwardly extending side portions 1 6 of the plate 12 extend beyond the upper plate 14 to provide support means for the latch plate at a position spaced from the socket. Although a fixed support means could be provided, the portions 1 6 journal a transversely extending guide roller 26 which bears against the rear face of the latch plate 24 and ensures that the latch plate is kept at right angles to the planes of the two socket plates when loaded by withdrawal forces acting on the tongue part 1, so enhancing the strength of the latching connection between the buckle parts.

The upper and lower plates 1 2, 14 are fixedly received in a housing comprising upper and lower housing parts 29, 30 moulded in plastics material and welded together. The housing parts are shaped to co-operate with the forward end of the socket plates to define the mouth 1 5 of the socket, and the upper housing part 29 has an opening extending rearwardly from the forward end of the upper socket plate. This opening accommodates a push or release button 31 which can be slid manually in the rearward direction to effect release of the tongue from the socket. The release button comprises a front wall 22 which inclines rearwardly and upwardly from the socket mouth. The free end of the wall 32 slides along an upwardly and rearwardly turned portion 34 of the upper housing part 29.A top wall 35 extends rearwardly from the front wall 32 to beneath the transverse edge of the opening in the upper housing part 29. The inclination of the front wall 32 of the release button minimises the risk of inadvertent actuation of the button to cause the tongue to be released from the socket.

Beneath the upper housing part 29, the release button 31 is provided with a rearwardly projecting stub 36 received in one end of a compression return spring 38 having its other end received in a pocket 39 formed on the inner side of the upper housing wall. The spring 38 thus acts between the release button 31 and the upper housing part 29 to urge the release button to the position shown which is defined by suitable stop means (not shown).

Side walls 40 extend downwardly from the top wall 35 and rearwardly from the front wall 32.

Along the lower edges of the side walls 40, slots extend in thickened internally projecting portions of the walls, into which the free edges of the upper plate 14 are slidably received to guide the button 31 for movement parallel to the movement of the tongue in the socket.

Between the top wall 35 and its lower edge, each of the side walls 40 is provided with a guide slot 41 which extends downwardly and rearwardly from a position in the front wall 32. In these guide slots 41 are received the lugs 28 projecting from the latch plate 24. Rearward movement of the release button 31 causes the latch plate 24 to slide upwardly, the release button eventually reaching a position of maximum compression of the return spring 38 in which the latch portions 25 are clear of the socket, permitting insertion and withdrawal of the tongue. Return movement of the release button 31 moves the latch plate 24 back into the latching position illustrated.The release button 31 will be seen to enclose the latch plate 24, to ensure that this cannot be inadvertently released in use by internal forces such as might be experienced during an accident to a vehicle in which the buckle is installed.

The side walls 40 each have a rearwardly extending portion providing an upwardly facing surface provided with a transversely extending L-shaped recess 42. A leaf spring 44 secured between the rivet head and the upper surface of the upper socket plate 1 4 extends forwardly and carried at its free end a transversely extending catch member 45 which is L-shaped in cross section, to match the cross section of the recesses 42. As the release button 31 is moved rearwardly into the housing, the ends of the catch member 45 slide on the release button side walls until they are urged by the leaf spring into the recesses 42. The release button is thus held against the forward movement urged by the now fully compressed return spring 38.

Slidably guided between the upper and lower socket plates 1 2, 14, is an ejector bar 46 which extends transversely across the socket for engagement by the nose 6 of the tongue. An ejector spring 48 acts between forward facing surfaces of apertures in the upper and lower socket plates and the rear face of the ejector bar 46, so as to urge this forwardly out of the mouth.

On insertion of the tongue into the socket, the ejector bar 46 is pushed inwardly by the nose 6, compressing the ejector spring 48. When the tongue is released, by movement of the latch plate 24 upwardly to withdraw the latch portions 25 from the socket, the ejector spring 48 urges the bar 46 forward to expel the tongue from the socket. The ejector bar 46 has a guide portion 49 extending upwardly through an aperture in the plate 14 and having a rearwardly facing guide surface 50 for engaging the centre portion of the catch member 45 in the rearward position of the bar, so as to lift the member out of the recesses 42, against the leaf spring 44.

The operation of the buckle is now described.

From the illustrated position in which the tongue is latched within the socket, the tongue is released by manual pressure on the release button 31. The lugs 28 of the latch plate 24 are guided by the cam slots 41 in the release button side walls 40 to raise the latch plate 24. At a predetermined rearward position of the release button 31, the latch portions 25 of the latch plate clear the edges 5 of the tongue, so that this is expelled from the socket by the ejector bar 46, powered by the energy stored in the ejector spring 48. The catch member 45 has then entered the L-shaped recesses 42 so the release button 31 is retained by the catch member in its inner or release position as long as the buckle remains out of use.

When the buckle comes again into use, the user inserts the tongue into the socket so that the nose 6 engages the ejector bar 46 and pushes this inwardly against the ejector spring 48. The ejector bar guide portion 49 is moved rearwardly, and its guide surface raises the catch member 45 out of the recesses 42 of the release button 31. The button return spring 38 is then free to act and the release button consequently moves forward to the position shown. This movement is necessarily accompanied by downward movement of the latch plate 24, so that the tongue is firmly held within the socket by the latch portions 25. In the forward position, the button overlaps or shrouds the latch plate against lateral release.

As the latch plate is held in a position withdrawn from the socket during insertion of the tongue, there is no transverse loading of the tongue during insertion. The only resistance to insertion comes from the action of the ejector spring on the ejector bar, precisely in the direction in which the tongue is being inserted.

The other buckles illustrated all have tongue parts corresponding to the tongue part 1 of Figure 2 and socket parts including lower and upper plates, housing parts and a release button corresponding generally to those of the socket part of Figures 1 and 3. These components are identified in the remaining drawings by the reference numerals used in Figures 1 and 3 and their nature and function are described below only so far as the differences between the other buckles and that of Figures 1 to 3 make this necessary. In particular, the plates 12, 14 will be provided with apertures which are differently shaped in each buckle for co-operation with the other parts thereof, which aperture shapes will not in general be specifically described as they can be readily deduced from the drawings and description.

The second buckle illustrated in Figures 4 to 7 has a latch plate 24 shaped and functioning as in Figures 1 and 3, but the ejector bar 46 has the guide portion 49 omitted. The ejector bar 46 has a concave front edge 1 51 shaped to receive the nose 6 of the tongue, and a pin 152 extending rearwardly to receive the spring 48. The bar has rearwardly facing steps 1 54 at its sides and a projection 1 55 underneath, by which the bar is guided in a longitudinally extending slot in the socket frame plate 1 2.

In the release position shown, the bar 46 underlies the latch portion 25 so the latch plate 24 cannot descend to the latching position, with forward movement of the button 31, under the force of spring 38, until the ejector, functioning as an anti-latching member, is moved inwardly by insertion of the tongure into the socket, when latching takes place. Movement of the button 31 inwardly raises the latch plate 24, allowing the ejector bar to move forwardly to eject the tongue and to prevent return to the latching position. The ejector bar thus functions as anti-latching means.

Although the buckle as so far described functions satisfactorily, it is preferred, to render false latching virtually impossible, to include as shown a special anti-latching member, or secondary ejector, which co-operates with the ejector bar to act as a tandem ejector system.

The anti-latching member 1 60 has a transversely-extending portion with forwardlyextending portions 1 61 at its sides spaced apart for reception beneath the lugs 28 of the latch plate 24. A central rearwardly-extending pin 1 62 is received in one end of a compression spring 1 64 the other end of which is trapped in a retainer 1 65 secured to the socket frame. The anti-latching member 1 60 has at each side a downwardly and inwardly extending portion 1 66 by which it is slidably guided on the upper plate 14.

In the release position of the socket part shown in Figure 4, the ejector 46 is urged by the spring 48 into its forward position defined by engagement with the parts of the cover around the socket mouth. The anti-latching member 160 is likewise urged forward by the spring 1 64 and the portions 161 are received between the lugs 11 and the upper socket plate 14 to hold the latch plate in a non-latching position, with the push button 31 in its rearward or release position.

On insertion of the tongue, the nose 6 engages the ejector bar 46 and moves this rearwardly.

After a certain rearward movement, the shoulders 1 54 engage the portions 1 66 of the anti-latching member 1 60 so that as the bar 46 is moved further inwardly the member 160 is carried rearwardly also. This movement continues until the portions 161 are withdrawn from beneath the lugs 28 so releasing the push button and the latch plate for return to the latching position. By this time the latch edges 5 of the tongue are beyond of the aligned apertures in the plates 12, 14 through which the latch plate portions now extend. The two buckle parts are thus securely latched together.

On inward movement of the push button 31, the latch plate 24 is raised until the tongue edges 5 are cleared. The ejector bar 46 moves outwardly together with the anti-latching member 1 61 to expel the tongue. Both springs 48 and 1 64 are involved in this movement until the member 160 abuts the latch plate, the projections 161 being then under the lugs 11. The ejector bar completes the forward movement under the force of the spring 48 alone.

The side portions 1 6 of the socket frame plate 12 are formed with rear and front guide legs 172, 1 74 between which the latch plate slides. A roller could be supported on the legs 1 72 but instead a rounded projection 1 71 is formed at the top of each of these legs to reduce friction between these legs and the latch plate.

In the third buckle embodying the invention, illustrated in Figures 8 and 9, the side portions 16 of the lower plate 12 extend upwardly beyond the upper plate 14 and receive in apertures therein a rod 51 which rotatably carries a spool member 52 which functions both as a latch member to hold the tongue of the tongue part 1 in the socket between the plates 12, 14 and as an ejector member. The spool member 52 has a generally cylindrical external surface but is provided with axially extending slots 54, 55 facing respectively generally rearwardly and downwardly. The lower slot 55 extends to the axial aperture of the spool member by which it is mounted on the rod 51 and is defined by forward and rear ridges 56, 58 of which the forward ridge 56 is divided by a central gap. Both ridges 56, 58 extend through an aperture in the upper plate 14 into the socket in the locking position shown, but rotation of the spool member in the anticlockwise direction brings the forward ridge 56 clear of the socket.

A stop 59 extends axially from one end wall of the spool member 52 at a position spaced from its axis, and co-operates with a slot formed in the adjacent side wall 1 6 so as to limit the angle through which the spool member can rotate. At its other end, the spool member has an axial extending hole 60 closely adjacent the rod 51 which receives one end of a torsion spring 61 coiled around the rod; the other end of this spring extends through the aperture in the upper plate 14 and is received in a circular aperture in the lower plate. The spring 61 tends to rotate the spool member 52 anti-clockwise from the position shown in Figure 8.

A generally rectangular catch element 70 has projecting end portions 71 fixedly received in apertures in the side walls 40 of the button 31 so as to extend tranversely across and above the upper plate 14. A central catch portion 72 extending forwardly from the catch element is inclined downwardly at about 15O for reception in the rearwardly facing slot 54 of the spool member 52. The catch element 70 and the spring 38 acting on it through the button 31 constitute a catch mechanism for the spool member 52.

In the illustrated position of the buckle, the tongue is fully received in the socket and is held therein against withdrawal by engagement of the edges 5 against the ridge 56, the neck 4 being received between the two parts of this ridge. This position is maintained against withdrawal forces acting on the tongue part 1, which will tend to rotate the spool member 52 anti-clockwise, by the reception of the catch portion 72 of the catch element 70 in the rear slot 54 of the spool member. The catch element 70 is held in this position by the button 31, undesired inward movement of which is resisted by the spring 38.

The withdrawal forces are applied by the edges 5, through the spool member 52, to the lower plate 12, and thus to the mounting bracket 20. To a certain extent, such forces are applied through the catch element 70, which bears on an upper edge 19 of the side portion 1 6 of the lower plate 12.

When the tongue part 1 is to be released, the button 31 is moved inwardly, to free the catch element 70 from engagement with the spool member 52; the latter then rotates anti-clockwise because of the torsion spring 1 6. The forward ridge 56 of the spool member 52 thus disengages from the latch edges 5 and moves out of the socket. The rear ridge 58 acts on the inner side of the tongue to positively eject this from the socket.

The stop 59 engages the side portion 1 6 so as to limit anti-clockwise rotation of the spool member 52. The button 31 cannot return to the forward position shown because the catch portions 72 engages an unslotted part of the periphery of the spool member.

When the buckle is to be refastened, the tongue is inserted in the socket. The forward ridge 56 of the spool member 52 is at this time clear of the socket, and the nose 6 engages against the rear ridge 38 to cause the spool member to rotate clockwise, so bringing the forward ridge into latching engagement with the latch edges 5 of the tongue. The catch portion 72 of the catch element 70 now enters the rear slot 54 in the spool member, the push button 31 moving forwardly with it, under the bias of the return spring 38. The buckle has thus been restored to the latching position illustrated.

The inclination of the catch portion 12 to the direction of movement of the catch member causes initial anti-clockwise rotation of the spool member 52 as the latch member is withdrawn.

This inclination can be selected to provide a predetermined release load.

In a modification, the catch member 70 is slidably received in slots in the side walls 40, so that there is a lost motion connection between the member and the button 31, and biassed forward by a separate spring, the button then being free to move forward to the position shown even though the spool member is in release position.

In the fourth buckle embodying the invention, shown in Figures 10 and 11, the push or release button 31 slides along the upper edges of the side portions 1 6 of the lower plate 12. The push button top wall 35 has downwardly extending guide portions 81 sliding on the inner surface of the side portions 1 6 and its upper surface is guided by the overlapping edges of the side walls of the upper housing part 29.

Above the upper plate 14, the side portions 1 6 of the lower wall 12 have transversely aligned apertures journalling a pivot pin 82 carrying a spaced pair of latch plates 84, which together constitute a latch member. Each plate 84 has transverse forward and rear teeth 86 and 88 both of which extend through apertures in the upper plate 14 floor into the socket in the latching position shown so that the teeth 86 can function as latch portions. Rearwardly of the apertures, the side portions 1 6 have transversely aligned longitudinally extending slots in which is received a transversely extending catch element in the form of a bar or rod 90.A spring 91 extending around the catch bar 90 and the pivot pin 82 acts to pull these together, so that the catch bar tends to occupy the forward end of the slots in which position it is received in downwardly and rearwardly facing recesses 94 in the plates 84 so as to prevent anti-clockwise rotation of these.

The downwardly extending guide portions 81 have elongate recesses 94 opening from their forward edges to accommodate the pivot pin 81 and enable the push button 31 to move rearwardly, and at the lower rear corners, the guide portions have rearwardly and downwardly facing recesses 96 corresponding generally in shape to the recesses 94 in the plates 84.

In the latching position shown, the tongue is received in the socket and withdrawal forces acting on the tongue part 1 cannot rotate the latch plates 84 anti-clockwise because of the latch bar 90. The withdrawal forces are applied through the plates 84 and the pivot pin 82 to the upper and lower plates 12,14 and thus to the connection of the socket part to the vehicle. An ejector spring 95 retained in central longitudinally extending slots in the socket plates may be provided to abut the nose 6 of the tongue so that the spring is held in a compressed condition.

To effect release of the tongue from the socket and thus separation of the two buckle parts, the push button 31 is manually pushed rearwardly.

The recesses in the guide portions 81 engage the latch bar 90 and move it rearwardly in the slots.

This frees the retainer plates 84 for anti-clockwise rotation which takes place because the tongue is withdrawn manually and/or ejected by the spring 95 and effects the rotation by a camming action on the teeth 86. The plates 84 thus turn to the position shown in broken line in which the forward teeth 84 are clear of the socket and the rear teeth 88 are received in an aperture in the lower plate 12.

Following separation of the buckle parts and removal of manual pressure on the push button 31, this moves forward to the position shown because of the spring 38, independently of the bar 20. The bar is pulled forward by the spring 91 but engages peripheral portions 95 of the plates 84 above the recesses 94 which are profiled so that clockwise return rotation of the plates is prevented.

Re-connection of the buckle parts occurs when the nose 6 of the tongue cams the latch plates 84 anti-clockwise by engaging the rear teeth 88. The bar 90 rides over the peripheral portions 95 and then moves forwardly into the recesses 94 to prevent return rotation of the plates 84 until the button 31 is again pushed in.

In a modification, the latch bar 9 is fixedly carried by the button 31 so that the latter is held in the release position when the buckle parts are separated. The spring 91 is then omitted, as the bar 90 is then urged into the latching position by the spring 38.

The fourth buckle embodying the invention shown in Figures 12 and 1 3 has a socket part of which the side portions 1 6 of the lower plate 1 2 serve only for securement of the upper wall 14.

The push button 31 slides along the side edges of the upper plate 14.

The button 31 carries a catch element 1 70 in the form of a transversely extending roller rotatably journalled at its ends in the push button side walls 40. A latch member 132 has a central plate-like portion 1 34 which lies directly on the upper plate 14 in the position illustrated, a platelike rear portion 1 35 which extends rearwardly and upwardly from central portion, and transversely spaced latch portions 1 36 which extend downwardly from the front edge of the central portion through apertures in the socket plates 1 2, 1 4 into the socket for engagement with the edges 5 of the tongue to thereby retain the tongue in the socket.

The latch member 132 is held in the latching position shown by the catch roller 1 70 which overlies its central portion 1 34.

An ejector member 138 is slidably received in the socket and is guided by portions received in slots in the plates 12, 14 for movement toward the socket mouth under the bias of a compression spring 141 received between the rear ends of apertures in the sockets and rearwardly extending pin 135 of the ejector member. In the position shown, the forward edge of the ejector member engages the nose 6 of the tongue.

Release of the tongue from the socket is effected by manual rearward movement of the button 31 against the bias of the return spring 38.

The catch roller 170, carried rearwardly by the button, attempts to ride up the rear portion 135 of the latch member and consequently the latter is pivoted anti-clockwise, the latch portions 1 36 being lifted clear of the socket. The underneath join of the portions 1 34, 1 35 is curved to make this tilting of the latch member a smooth rolling movement. The ejector member 138 then moves the tongue out of the socket and in doing so reaches a forward position, determined by the engagement of the guide portions of the ejector member with the forward ends of the guide slots in the plates 12, 14, in which it functions as an anti-latching member because the upper surface of the ejector member underlies the upper plate aperture 124 through which the latch portions 136 have been lifted.The retainer member 132 and the push button 31 are thus held in the release position. The spring 38 urges the push button forwardly and upwardly lifted central portion 134 because the engagement of the latch portions 1 36 on the ejector member prevents clockwise tilting.

Re-insertion of the tongue into the socket pushes the ejector member 138 rearwardly so that when the aperture 124 is cleared, the catch roller 1 70 can act on the latch member to restore the latching position shown. Withdrawal forces acting on the tongue are applied from the latch edges 5 to the latch portions 1 36 and are taken up by the plates 12, 14 at the forward edges of the apertures therein, the latter edge of the plate 14 being formed by an upwardly rolled portion 122.

In a modification, the catch roller 1 70 is guided in slots in the push button side walls 40 extending in the direction of movement of the button and permitting the button to return to the illustrated position when the tongue is absent from the socket. Additional spring means acts on the roller 170 to urge this forward in the slots so that the roller can tilt the latch member clockwise on insertion of the tongue when this becomes possible, because the tongue edges 5 have passed beyond the aperture 124.

The invention can be embodied in a variety of ways other than as specifically described. For example as shown in Figure 14, a modified tongue part 100 can comprise a flat metal plate with a different kind of latch formation from that of the tongue 1 of Figure 2. The modified tongue part 100 again has a belt connection aperture 102 at one end and a rounded nose 106 at the other, but only a single latching edge 105 is provided, by means of a central aperture 104 in the tongue. It will be evident that the socket parts of the buckles illustrated in Figures 1 to 1 3 can be readily modified to receive this tongue part 100, by providing the latch member with a single central latch portion instead of two transversely spaced latch portions.

Claims (14)

1. A vehicle seat belt buckle comprising a tongue part, the tongue part having a tongue with a latch formation, and a socket part, the socket part having a socket for receiving the tongue and a latch mechanism with a latch member, the latch member having a latching position in which the latch member engages the latch formation when the tongue is in the socket to thereby latch the buckle parts together and being movable from the latching position to allow the tongue to be withdrawn from the socket, and the latch mechanism being arranged to hold the latch member substantially clear of the path of the tongue into the socket in the absence of the tongue therefrom.

2. A buckle as claimed in claim 1 wherein the latch member is held clear of the path of the tongue agains a bias by a catch device releasable on insertion of the tongue into the socket to permit movement of the latch member to the latching position under the bias.

3. A buckle as claimed in claim 2 wherein the latch mechanism includes a push button actuable against the bias to move the latch member from the latching position, and the catch device is arranged to engage with the button.

4. A buckle as claimed in claim 2 or 3 having an ejector member engageable by the tongue on insertion thereof into the socket and spring biassed to oppose such insertion, the ejector member having a portion engaged to release the catch device on insertion of the tongue into the socket.

5. A buckle as claimed in claim 4 as dependent on claim 3 wherein the catch device comprises a spring-urged detent arranged to engage in a recess in the button on actuation thereof and the ejector member portion is arranged to lift the detent member from the recess on insertion of the tongue into the socket.

6. A buckle as claimed in claim 3 or 5 wherein the push button and latch member are linked by a mechanism comprising a groove in one thereof drivingly receiving a projection of the other.

7. A buckle as claimed in claim 2 wherein the catch device comprises an anti-latching member in the socket having an anti-latching position in which the latch member engages the anti-latching member and is prevented thereby from moving to the latching position, the anti-latching member being movable from the anti-latching position by the tongue on entry thereof into the socket.

8. A buckle as claimed in claim 7 wherein the anti-latching member is spring biassed to oppose said entry of the tongue to thereby function to eject the tongue on release of the latch mechanism.

9, A buckle as claimed in claim 2 wherein the catch device comprises a first member engageable by the tongue on entry thereof into the socket and spring biassed to oppose said entry and a second member spring biassed to a position interposed between the latch member and the socket to prevent latch member movement to the latching position, the second member being movable to permit said movement by the first member after a predetermined movement thereof with the tongue on entry into the socket.

10. A buckle as claimed in claim 7, 8 or 9 having a push button operably linked with the latch member and movable against a spring to withdraw the latch member from the latching position, the spring urging the latch member to the latching position.

11. A buckle as claimed in any preceding claim wherein the latch member is guided for movement in a direction substantially perpendicular to the direction of movement of the tongue into and out of the latching position by a guide means supporting the latch member at a position spaced from the socket against withdrawal forces acting on the tongue.

1 2. A vehicle seat belt buckle comprising a tongue part, the tongue part having a tongue with a latch formation, and a socket part, the socket part having a socket for receiving the tongue, a latch mechanism with a latch member. The latch member having a latching position in which the latch member engages the latch formation when the tongue is in the socket to thereby latch the socket parts together, and being movable from the latching position transversely of the direction of movement of the tongue into the socket, and guide means spaced from the socket supporting the latch member against forces tending to withdraw the tongue from the socket.

13. A buckle as claimed in claim 11 or 12 wherein the guide means comprises a roller.

14. A buckle as claimed in any one of claims 10, 11, 12 or 1 3 wherein the release member has a manually engageable end wall, the end wall being inclined away from the direction of movement of the tongue into the socket.

1 5. A buckle as claimed in any preceding claim wherein the latch member comprises a latch plate extending transversely of the direction of movement of the tongue into the socket.

1 6. A buckle as claimed in any preceding claim having anti-latching means arranged to releasably retain the latch member in the release position thereof and to permit return of the latch member to the latching position in response to insertion of the tongue into the socket.

14. A buckle as claimed in claim 1 wherein the latch member is arranged to turn from the latch position about an axis extending transversely of direction of movement of the tongue into the socket, a catch element being arranged to hold the latch member in its latching position and to be movable to free the latch member when the latch mechanism is operated to release the tongue.

1 5. A vehicle seat belt buckle comprising a tongue part, the tongue part having a tongue with a latch formation, and a socket part, the socket part having a socket for receiving the tongue. a latch mechanism with a latch member, the latch member having a latching position in which the latch member engages the latch formation when the tongue is in the socket to thereby latch the buckle parts together and being movable from the latching position to permit separation of the parts, and a catch element arranged to hold the latch member in the latching position thereof and to be movable to permit the latch member movement when the latch mechanism is operated to release the tongue.

16. A buckle as claimed in claim 14 or 15 wherein the catch element is spring biassed to hold the latch member in the latching position thereof.

17. A buckle as claimed in claim 14, 15 or 16 wherein the catch element has a catch portion engageable in a recess in the latch member, the catch portion being inclined to the direction of movement of the catch element so as to tend to turn the latch member from the latching position thereof on withdrawal of the catch portion from the recess.

18. A buckle as claimed in claim 17 wherein the catch element has a sliding engagement with a surface of the latch member during movement of the latch member to the latching position, the surface being so shaped that such latching movement is opposed by the spring bias acting on the catch element.

19. A buckle as claimed in claim 1 6, 17 or 18 wherein the catch element is spring biassed by a spring acting between the catch element and a shaft on which the latch member turns.

20. A buckle as claimed in any one of claims 14 to 19 wherein the latch member has a portion arranged to be engaged by the tongue on insertion into the socket to thereby move the latching member into the latching position.

21. A buckle as claimed in claim 20 wherein a spring bias acting on the latch member causes the portion to function as an ejector means to urge the tongue out of the socket on release movement of the latch mechanism.

22. A buckle as claimed in claim 20 having an ejector spring arranged to be compressed by the tongue on insertion into the socket and to assist ejection of the tongue from the socket on operation of the release mechanism.

23. A buckle as claimed in claim 14 or 1 5 wherein the latch member has first and second inclined surfaces, and the catch element is movable from the holding position in which it engages the first surface to a release position in which it engages the second surface thereby rocking the latch member from the latching position.

24. A buckle as claimed in claim 23 wherein the first and second surfaces are provided by first and second relatively inclined plate portions which rest on a socket wall in the latching and release portions respectively, the first plate having a laterally projecting latch portion.

25. A buckle as claimed in claim 24 wherein the inclined plate portions are joined at the sides thereof remote from the surfaces by a rounded edge on which the latch member rocks.

26. A buckle as claimed in claim 24 or 25 having a spring urged ejector slidable in the socket to resist insertion of the tongue, the ejector presenting entry of the latch portion into the socket in the release portion until entry of the tongue.

27. A buckle as claimed in any one of claims 14 to 26 wherein the latch mechanism comprises a manually actuable press button, actuation of which withdraws the catch element from the holding position thereof.

28. A buckle as claimed in claim 27 wherein the catch element is fixedly connected to the push button.

29. A buckle as claimed in claim 27 having a lost motion connection between the catch element and the push button, the push button being actuable against the action of a spring.

30. A buckle as claimed in any preceding claim wherein the tongue comprises a flat plate and the socket is defined by a channel member and a plate member secured to the channel member to extend therein substantially parallel to the floor thereof.

31. A buckle substantially as herein described with reference to Figures 1, 2 and 3, Figures 4 to 7, Figures 8 or 9, Figures 10 or 11, Figures 12 and 1 3 or those Figures as modified by Figure 14.

New claims or amendments to claims filed on 22/12/82.

Superseded claims 1-31.

New or amended claims:- 1-16.

1. A vehicle seat belt buckle comprising a tongue part, the tongue part having a tongue with a latch formation, and a socket part, the socket part having means providing a socket for receiving the tongue, a latch member, the latch member being non-rotationally movable transversely of the direction of movement of the tongue into the socket between a latching position in which the latch member engages the latch formation when the tongue is in the socket to thereby latch the buckle parts together and a release position permitting withdrawal of the tongue from the socket, and guide means providing an abutment supporting the latch member at a position spaced from the socket against forces tending to withdraw the tongue from the socket.

2. A buckle as claimed in claim 1 wherein the guide means is carried by the means providing the socket.

3. A buckle as claimed in claim 1 or 2 wherein the guide means comprises roller means.

4. A buckle as claimed in claim 1 or 2 wherein the guide means comprises at least one projection engaging the latch member over a limited area.

5. A buckle as claimed in claim 1 wherein the means providing the socket comprises a channel member having a centre portion providing a boundary of the socket and side portions providing the guide means.

6. A buckle as claimed in claim 5 wherein the guide means comprises a rollerjournalled on the channel member side portions.

7. A buckle as claimed in claim 5 wherein the guide means comprises a projection on each of the channel member side portions engaging the latch member over a limited area.

8. A buckle as claimed in claim 4, 5 or 7 wherein the channel member side portions have slots within which the latch member moves.

9. A buckle as claimed in claim 5, 6, 7 or 8 wherein the means providing the socket comprises a plate member extending between the channel member side portions parallel to the centre portion thereof.

10. A buckle as claimed in any preceding claim having a release member slidably guided for manual movement substantially parallel to the direction of movement of the tongue to effect movement of the latch member to the release position.

11. A buckle as claimed in claim 10 having surface means on the release member inclined to the direction of movement thereof engageable with projections on the latch member.

12. A buckle as claimed in claim 10 having pin and slot means operatively linking the release member and the latch member for movement thereof together.

13. A buckle as claimed in claim 10, 11 or 12 wherein the release member comprises a channel member having a centre wall and side walls, the side walls being slidably guided on the plate member.