EP0064526A1

EP0064526A1 - Improvements relating to strap buckles

Info

Publication number: EP0064526A1
Application number: EP19810903111
Authority: EP
Inventors: John Philip Hancock
Original assignee: British Aluminum Co Ltd
Current assignee: British Aluminum Co Ltd
Priority date: 1980-11-25
Filing date: 1981-11-24
Publication date: 1982-11-17
Also published as: GB2088461A; WO1982001809A1

Abstract

Boucle de sangle utilisee avec des sangles comprenant une base (1) ayant une partie constituant un premier organe (6) d'engagement d'une sangle et un couvercle (3) pivotant sur la base adjacente a l'organe et portant un second organe (29) d'engagement d'une sangle, s'etendant parallelement au premier organe, la base etant extrudee en materiau metallique ou plastique dans une direction parallele aux axes des organes, ouverture (22) etant amenagee dans la base entre la position du premier organe et un ancrage pour une extremite de sangle, l'ouverture etant prevue pour recevoir une autre extremite de sangle passant sur le premier organe, autour du second organe et revenant par dessus le premier organe vers une position accessible de l'exterieur de la boucle.Strap buckle used with straps comprising a base (1) having a part constituting a first member (6) for engaging a strap and a cover (3) pivoting on the base adjacent to the member and carrying a second member (29) for engaging a strap, extending parallel to the first member, the base being extruded from metallic or plastic material in a direction parallel to the axes of the members, opening (22) being brought into the base between the position of the first member and an anchorage for one end of the strap, the opening being provided to receive another end of the strap passing over the first member, around the second member and returning over the first member to a position accessible from outside the loop.

Description

TITLE: "IMPROVEMENTS RELATING TO STUAP BUCKLES"

This invention relates to a strap buckle. It is common practice to secure loads, for example, in aircraft holds and on lorries, with webbing straps secured at their one ends to fixed parts of the vehicle structure and coupled at their other ends to a buckle which, in an open position permits a free end of one of the straps to be pulled through the buckle to tighten the straps around the load and in a closed position clamps the straps against further movement to secure the load.

Usually the free end of the strap is passed over a first member around a roller and is threaded back over the first member to be accessible outside the buckle. The roller is pivotable about a position adjacent the first member and in the open position of the buckle the line between the roller and the member extends at an oblique angle to the straps and permits the free end to pass easily around the roller and in the closed position of the buckle the line between the roller and the member extends at an acute angle to the straps to increase the friction between the straps, the roller and the member. The buckle is generally held in its closed position by a releasable spring clip. Usually such buckles are fabricated from steel sheet; they are heavy and in spite of the use of protective surface finishes they deteriorate rapidly and become increasingly difficult to use. Aluminium alloys have been used for at least parts of such buckles but similar fabrication methods have been employed and aluminium alloy buckles are expensive.

It is accordingly an object of the present invention to provide an improved buckle, for use with webbing straps, which can be easily and expensively made from an aluminium alloy or a plastics material.

According to one aspect of the present invention there is provided a strap buckle for- use with webbing straps comprising a base having a part constituting a first strap engaging member and a cover pivoted to the base adjacent the member and carrying a second strap engaging member extending parallel with the first member, the base being extruded from metal or plastics material in a direction parallel with the axes of the members and subsequently being formed with an aperture' between the location of the first member and an anchorage for one strap end, the aperture being to receive another strap end passed over the first member, around the second member and back over the first member to a position accessible externally of the buckle. The end of the base remote from the first member may be defomable and is either formed as or carries a latch for holding the cover in its closed position. Preferably said end includes an end wall extending at an angle to the base and formed at its free end with a latch formation engagable by the cover to hold the latter in its closed position. The above and other aspects of the present invention will now be described by way of example with reference to the accompanying drawings in which:- Fig. 1 is a section on the line I-I of Fig. 2 and shows the strap buckle arranged vertically with its cover in the closed position; the open position of the cover being indicated by chain lines, Fig. 2 is a plan view of the buckle with the cover closed,

Fig. 3 is an end view of the buckle, Fig. 4 is a section on the line of Fig. 5 and is a view similar to Fig. 1 of a modified buckle, Fig. 5 is a view similar to Fig. 3 of the modified buckle and

Fig. 6 is a view similar to Fig. 3 of the modified buckle.

Referring to Figs 1 to 3 of the drawings a buckle, indicated generally at 1, comprises a base 2 a cover 3 and a release member 4. The base 2 is extruded from a suitable aluminium alloy and has a central flat part 5 formed towards one end constituting a bar 6 with a formation 7 the interior 8 of which is part circular in cross section. At its other end the part 5 has an inwardly curved part 9 and an outwardly extending flange 10 separated from the part 5 by a shoulder 11. A rear part 12 of thinner section than the part 5 extends parallel therewith rearwardly of the flange 10 and at its outer end merges with an end wall 13 extending at right angles thereto. Towards its outer end the wall 13 is formed with a rounded beading 14 having an inner surface 15 and spaced from this inner surface a rib 16 extends across the end wall, the space between the rib 16 and the surface 15 constituting a latch as will hereinafter be described. Intermediate its length the end wall is formed with a further rib 17 the upper part of which is inclined at 18. As shown in Fig. 2 the side edges 19 and 20 of the base are tapered from a position adjacent the formation 7 to the end wall 13. As shown particularly in Figs. 1 and 2 the end 6 of the base 2 is separated from the formation 7 by a web 21 or reduced thickness. As the base 2 is extruded the emerging extrusion is punched both to cut the outline tapered shape and also to form an aperture 22 in the web, 21. Either simultaneously or in a subsequent operation the flange 10 is punched to form an elongated aperture 23 therein.

The cover 3 is of -U- shape in section and comprises a pair of tapered side walls 24 and 25 joined by a web 26. The cover is pressed from sheet aluminium alloy. As shown in Fig. 1 the cover is disposed over the base 2 with the wider ends of the walls 24 and 25 embracing the formation 7 and a tubular rivet 27 incorporating a steel pin 28 is passed through the walls and through the formation 7 to constitute a pivot for the cover. A roller 29 incorporating a steel pin 30 extends between the side walls 24 and 25 of the cover 3.

As shown in full lines in Fig. 1 the cover is in its closed position with its end 31 held by the latch at the outer end of the end wall 13 it being understood that to close the cover the end 31 engages the beading 14 to deform the end wall 13 and the rear part 12 to distort these parts. In the closed position of the cover the roller 29 lies adjacent to but spaced from the part 5 in the base 2.

The releasing member 4 is also of -U- shape having side walls 32 and 33 joined by a web 34 the latter being formed with a slot 35 to enable the member 4 to be passed over the beading 14 and the rib 16 of the end wall 13 so that the member is located in the position shown in Fig. 1 with its inner end 36 lodged against the shoulder 11 of the base 2 and the inner edge of the slot 35 lodged beneath the rib 16. In this position the end wall 13 is flexed slightly to hold the member 4 firmly in position. In operation the buckle is generally disposed vertically as shown in Fig. 1 and one end 37 of a strap 38 is passed around the end 6 through the aperture 22 and secured by rivets 39. It will be assumed that the strap 38 passes around the upper part of a load for example on a lorry and is secured to a fixed part of the vehicle. Another strap 40, secured at its lower end (not shown) to a fixed part of the lorry, passes upwardly through the aperture 23 in the flange 10; through the aperture 22; around the roller 29 and back through the aperture 22 and the aperture 23 to provide a free end 41. As shown in Fig. 1 the outermost part of the formation 7 extending through the aperture 22 constitutes a first member 42 having a smooth surface around which the strap may readily slide. The threading of the strap 40 through the buckle is carried out with the cover 3 in its open position as shown in chain lines at 3a so that the roller 29 is in the position indicated at 29a. With the cover open, pulling on the free end 41 of the strap 40 permits the strap to pass freely over the member 42 and the roller 29 constituting a second strap engaging member 29 to take up slack in the strap. It will here be understood that this operation maintains the cover 3 in its open position 3a. since this position provides the minimum distance between the roller 29 (position 29a) and the member 42. When all the slack in the strap has been taken up the coyer is closed while the free end 41 of the strap is held. Closing movement of the cover pivots the latter about the rivet 27 and increases the distance between the roller 29 and the member 42 and at the same time increases the frictional engagement between the two layers of the strap until the latter is held tightly. The final closing movement of the cover 3 engages its end 31 over the beading 14 to flex the end wall 13 and latch the cover in position.

To release the cover the outer part of the member

4 is moved along the end wall 13 so that the inner surface of the slot 35 runs along the inner surface of the wall 13 and engages the inclined surface 18 to distort the wall 13 outwardly a distance sufficient to unlatch the end 31 of the cover. The inner end 56 of the member 4 pivots on the shoulder 11. Upon release the cover will immediately spring to the chain line position shown at 3a, under the tension of the straps.

As a precaution against accidental release, a pin, indicated by chain lines at 43, may be passed through apertures (not shown) in the walls 24 and 25 of the cover 3 to engage behind the curved part 9 of the base 2. It will be understood that the cover cannot be released from its latched position without first removing this pin. In a modification (not shown) the friction between the layers of the strap 40 could be increased by disposing the roller 29 nearer the inclined edges of the walls 24 and 25 and providing a recess (not shown) in the part 5 to accommodate the roller in the closed position of the cover 3. Substantially the same result could be achieved by disposing the part

5 on the other side of the formation 7 to be closely alongside the strap 40.

The above described arrangement of Figs 1 to 3 can be simplified by omitting the release member 4 and extending the beading 14 outwardly (not shown) in a direction parallel with the rear part 12. Hand pressure on this extended part will distort the wall 13 sufficiently to unlatch the end 31 of the cover. It will be understood that with this arrangement the part 5 may merge smoothly into the rear part 12. Figs. 4 to 6, in which like references have been used where appropriate, show a simplified buckle incorporating the above and other modifications. As shown in these figures the rear part 12 of the base 2 merges with the thicker part 5 at a smoothly curved shoulder 12a on the outside of the base. The bar 6 is laterally spaced outwardly from the base 2 and the formation 7 turns inwardly from the base at the outer end thereof. Since the pin 28 is now on the opposite side of the base 2 the pin 30 is disposed nearer to the web 26 of the cover 3. The curved part 9 may, for convenience also be oppositely disposed.

The arrangement of Figs. 4 to 6 is not only a simpler construction but it also offers improved performance particularly when the buckle is to be used with rough surfaced webbing straps since the cover 3 will open through180º so that, in its open position, as shown in chain lines in Fig 4, the pin 30 adopts the position 30a. and there is no "wrap 'around" of the formation 7 by the strap 40. This reduces friction and makes it particularly easy to pull the free end 41 of the strap through the buckle.

In the arrangement of Figs 4 to 6 the flanged 10 (Fig. 1) is unnecessary since in the open position there is no torgue tending to rotate the buckle. In all the constructions above described it is important that the part 5 of the base is sufficiently thick that it does not distort when the straps are under tension. Should distortion occur release of the buckle would be difficult since a component of the strap tension would need to be overcome as well as the latching spring force provided by the part 12 and the wall 13. The increased thickness of the part 5 is preferably (as shown in Fig. 4) at least partly on the strap side of the buckle so as to provide clearance for the straps and permit easy sliding.

Claims

CLAIMS .

1. A strap buckle for use with webbing straps comprising a base having a part constituting a first strap engaging member and a cover pivoted to the base adjacent the member and carrying a second strap engaging member extending parallel with the first member, the base being extruded from metal or plastics material in a direction parallel with the axes of the members and subsequently being formed with an aperture between the location of the first member and an anchorage for one strap end, the aperture being to receive another strap end passed over the first member, around the second member and back over the first member to a position accessible externally of the buckle.

2. A strap buckle according to claim 1 in which the end of the base remote from the first member is deformable and is either formed as, or carries, a latch for holding the cover in its closed position.

3. A strap buckle according to claim 2 in which said end includes an end wall extending at an angle to the base and formed at its free end with a latch formation engagable by the cover to hold the latter in its closed position.

4. A strap buckle according to any one of the preceding claims in which the anchorage and the first member are aligned longitudinally of the base.

5. A strap buckle according to any one of claims 1 to 3 in which the anchorage and the first member are aligned laterally of the longitudinal direction of the base.

6. A strap buckle according to claim 5 is. which the cover is pivotable through approximately 180° from its closed to its open position.

7. A strap buckle according to any one of claims 2 to 6 in which the end of the base adjacent the first member is sufficiently stiff as to be substantially non-deformable under the strap tension.

8. A strap buckle according to any one of claims

3 to 7 in which a releasing member is provided operable externally of the buckle and acting between the end wall and a fixed part of the buckle to deform the end wall outwardly in order to unlatch the cover.

9. A strap buckle according to any one of the preceding claims in which the cover is extruded from metal or plastics material in a direction at right angles to the axes of the members.

10. A strap buckle according to any one of the preceding claims in which at least one of the members is a roller.

11. A strap buckle according to any one of the preceding claims comprising removable locking means engagable with the base and the cover to prevent the latter being unlatched.

12. A strap buckle substantially as herein described with reference to Figs 1 to 3 or Figs. 4 to 6 of the accompanying drawings.