GB2029892A - Securing straps - Google Patents

Abstract

An arrangement for securing a strap, particularly a binding strap, to a structural part, has a region where the strap doubles back on itself to form two layers, there being three arms 3, 4, 5 for guiding and supporting the strap; a first of the arms (eg 4) resting in contact with the inner surface of an endloop 12 of the strap; a second of the arms having a portion of the strap slung at least partly around it in such a way that when tension is applied to the projecting end this portion of the strap squeezes a further, inner portion 9 tightly against the surface of the second arm. One of the arms 3 is fixed to the structural part, or is a part of it, the other two arms 4, 5 being opposite portions of an approximately oval clenching ring 6, made of round- section bar, which is in itself separate from the structural part but is attached to it, when the parts of the arrangement have been assembled together by slung-around portions of the strap. The loop may be formed over the bar not formed by the ring 6, Fig. 9. Other embodiments define more elaborate threading arrangements. <IMAGE>

Description

SPECIFICATION Arrangement for securing a strap to a structural part The invention relates to an arrangement for securing a strap, particularly a binding strap, to a structural part, the arrangement having a region where the strap doubles back on itself to form two layers; and three arms for guiding and supporting the strap; a first of the arms resting in contact with the inner surface of an end-loop of the strap; a second of the arms having a portion of the strap slung at least partly around it in such a way that when tension is applied to the projecting end this portion of the strap squeezes a further, inner portion tightly against the surface of the second arm.

An arrangement of this general kind is known in which the structural part has three arms arranged like the rungs of a ladder. The structural part therefore has a determined structure and consequently this kind of arrangement cannot be used when it is desired to secure a strap to an already existing structural part such as a transverse pin or bar of a structure. Furthermore, in the known arrangement the three arms are spaced equally apart and the strap can slip out when a high load is applied to it. Finally, the arms are stressed in an undesirable manner.

The intention in the present invention is to provide an arrangement of this general kind but which has a wider field of applications, is simpler in construction and is capable of taking higher loads.

The problem is solved, according to the invention, in that one of the arms is fixed to the structural part, or is a part of it, the other two arms being opposite portions of an approximately oval clenching ring made of round-section bar, which is in itself separate from the structural part but is attached to it, when the parts of the arrangement have been assembled together, by slung-around portions of the strap.

The arrangement according to the invention has the advantage that with the help of the simple, oval clenching ring, a strap can easily be secured to any likely structural part and subsequently just as easily released from it.

The clenching ring, being itself a separate structure, is able to move adaptively into its most effective clenching position, producing a good frictional lock with comparatively little stressing of the arms.

A particularly good arrangement is obtained if the gap between the arms of the oval clenching ring is equal to the total thickness of the strap layers in the gap, or only slightly greater. This gives the strap a firm seat in the clenching ring and promotes the clenching action.

The invention will now be described in greater detail with the help of the several examples represented in the drawings, in which: Figure 1 is a plan view, as seen from below, of a first example of the arrangement; Figure 2 is a section taken in the plane ll-ll of Fig. 1; Figure 3 is a corresponding section through a second example; Figure 4 is a plan view, as seen from below, of a third example; Figure 5 is a section taken in the plane V-V of Fig. 4; Figure 6 is a plan view, as seen from below, of a fourth example of the arrangement; Figure 7 is a section taken in the plane VII-VII of Fig. 6; Figure 8 is a plan view, as seen from below, of a fifth example; and Figure 9 is a section taken in the plane IX-IX of Fig. 8.

Figs. 1 and 2 show a structural part 1 in the form of a circular ring to which a strap is secured, as will now be described. The strap 2 is threaded through the interior of an approximately oval clenching ring made of round steel bar and somewhat resembling a link of a chain. The strap 2 passes over the lower arm 5 of the clenching ring 6, around the arm 3 of the circular ring 1, over and around the upper arm 4 of the clenching ring 6, again around the arm 3, inside the first pass of the strap, and out through the oval clenching ring 6 between the two earlier passes of the strap, finally terminating in a free strap-tail 7. It will be observed that, in this example, the strap-tail 7 is led out between two passes of the strap.The arrangement allows the entire structure, comprising the strap 2, to which tension is applied in the direction of the arrow 8, the clenching ring 6 and the slung-around portions of the strap to swing comparatively freely up and down about the arm 3, acting as a pivot pin, the surface of the strap sliding over the surface of the arm 3. This allows the strap to adopt, each time, its most natural load-bearing attitude, with the best clenching effect. The inner loop is clenched by the outer loop at 9 and at 10 the strap is clenched between the arm 4 of the clenching ring 6 and the arm 3 of the circular ring 1.

In the arrangement shown in Fig. 3 corresponding parts have been given the same index numbers. However, in this case the strap 2, instead of being secured to a ring 1, as in Figs. 1 and 2, is secured to a structural arm 11 and the strap can swing (in the plane of the paper) all the way around through 360 in adopting, each time its most natural loadbearing attitude, without this degrading the clenching effect of the arrangement. Thus here again the strap is free to swing around quite easily into its best position.

It will be observed that in the two examples shown in Figs. 1, 2 and 3, the end-loop 12 passes around the upper arm 4 of the clenching ring 6, and that the height of the gap between the two arms 4 and 5 of the clenching ring 6 is only slightly greater than the total thickness of the three strap layers situated between these two arms. Furthermore, the external width t of the clenching ring 6 is substantially the same as the width of the strap 2.

In Figs. 4 to 9 the same index numbers are again used for corresponding parts.

In the example shown in Figs. 4 and 5 the strap 2 is passed altogether four times around the arm 3 of the structural part, which here again is a ring 1. This enhances the locking effect. But this example has the disadvantage that the strap 2 cannot safely be allowed to swing around, in the plane of the paper, through more than 180 .

This disadvantage does not occur in the example of Figs. 6 and 7. In this example a particularly favourable frictional effect is obtained between the oval clenching ring 6, the arm 3 of the structural part 1 and the individual slung-around layers of the strap 2. And the strap 2 is free to swing about the arm 3 within wide angular limits, without degrading the clenching effect. As shown in Fig. 7, altogether four layers of strap go around the arm 3, which acts after the manner of a hinge-pin for the attachment structure.

In all the examples described up to now, the end-loop 1 2 goes around one or other of the arms 4, 5 of the oval clenching ring 6. In Figs. 8 and 9, on the other hand, the endloop 12 is taken around the arm 3 of the structural part 1, which is covered by three layers of strap in this region. In this example the strap is also free to swing in all directions, in the plane of the paper, so as to take the applied tension in the best manner.

All the examples have the advantage of great simplicity in construction. With the help of a substantially oval round-steel clenching ring, somewhat resembling a link of a chain, the strap can be secured easily and detachably to any likely structural part. Inadvertent detachment is excluded. The hold obtained has been found by experience to exceed the tensile strength of the strap. In other words it was found, in the course of experiments, that even the greatest load applied to the strap in the direction of the arrow 8 does not cause the strap-tail 7 to recede towards the interior of the attachment structure. On the other hand, the length of strap between the attachment structure and the load can be changed quite easily. Instead of a round-steel clenching ring one can use, if desired, a plate or the like containing an oval slot, but only if all the working edges have been well rounded off.

Claims (11)

1. An arrangement for securing a strap, particularly a binding strap, to a structural part, the arrangement having a region where the strap doubles back on itself to form two layers; and three arms for guiding and supporting the strap; a first of the arms resting in contact with the inner surface of an end-loop of the strap; a second of the arms having a portion of the strap slung at least partly around it in such a way that when tension is applied to the projecting end this portion of the strap squeezes a further, inner portion tightly against the surface of the second arm, characterised in that one of the arms is fixed to the structural part, or is a part of it, the other two arms being opposite portions of an approximately oval clenching ring, made of round-section bar, which is in itself separate from the structural part but is attached to it, when the parts of the arrangement have been assembled together by slung-around portions of the strap.

2. An arrangement as claimed in claim 1, characterised in that the arm fixed to the structural part, or forming a part of it, has a diameter which is greater than the gap between the other two arms.

3. An arrangement as claimed in claims 1 or 2, characterised in that the gap between the arms of the clenching ring is equal to the total thickness of the strap layers in the gap, or only slightly greater.

4. An arrangement as claimed in claims 1 to 3, characterised in that the internal width of the clenching ring is approximately the same as the width of the strap.

5. An arrangement as claimed in claims 1 to 4, characterised in that the end-loop of the strap contains one of the arms of the clenching ring.

6. An arrangement as claimed in claims 1 to 5, characterised in that the end-loop contains the arm fixed to the structural part, or forming part of it.

7. An arrangement as claimed in claim 5, characterised in that the strap is slung twice around the arm fixed to, or forming part of, the structural part, so as to form two strap layers.

8. An arrangement as claimed in claim 5, characterised in that the strap is slung four times around the arm fixed to, or forming part of, the structural part, so as to form four strap layers.

9. An arrangement as claimed in claim 6, characterised in that the strap is slung three times around the arm fixed to, or forming part of, the structural part, so as to form three strap layers.

10. An arrangement according to one of the claims 1 to 9, characterised in that the strap-tail, which takes no load, is sandwiched between at least two strap layers in the gap of the clenching ring.

11. An arrangement for securing a strap substantially as described with reference to any of the accompanying drawings.