GB2240359A - Clamp - Google Patents

Abstract

A wire rope clamp, shaped like a 'U' to embrace the rope's periphery, and with the rope-contacting inside surfaces of the U being wide enough to tend to flatten, rather than to bite into, the rope strands; the U being hinged in the region of its bend to allow it to be fitted over the rope at a given region along the rope's length without having to be slid along the rope from one end thereof; the opposite ends of the U being brought and held together, in clamping mode, by a fastener 23, 25 which, as it tightens, draws the U-ends together around the rope and which, like the U, can be opened to fit over the rope initially; and with respective locating bars 13, 14 projecting one from each opposite outside surface of the U. <IMAGE>

Description

CLAMP Field of the Invention The invention relates to clamps and is specifically concerned with a wire rope clamp.

Review of the Art known to the Applicants Wire rope clamps, particularly in the offshore industry, are known to consist of U-shaped clamps which embrace the rope's periphery and with each limb of the U-being externally threaded to accommodate a respective nut, the nuts tightening in use against a crossbar which fits over the threaded U-limbs and is drawn down by the nuts against the rope.

This known construction tends to bite into the strands of the rope. The force exerted by the nuts on the crossbar can be very large and it is easy to over-tighten them. The U-bend itself is usually profiled in cross section as to tend to bite into, rather than just to flatten down against, the rope periphery.

Although these known clamps work well, therefore, from a clamped-in-position point of view, they do tend to damage the ropes; and to secure a looped sling-eye in place they need further securing, for example by an electrical cable "Tyrap" interwoven through the eye and the clip.

Summary of the Invention According to the present invention there is provided a wire rope clamp, shaped like a 'U' to embrace the rope's periphery, and with the rope-contacting inside surfaces of the U being wide enough to tend to flatten, rather than to bite into, the rope strands; the U being hinged in the region of its bend to allow it to be fitted over the rope at a given region along the rope's length without having to be slid along the rope from one end thereof; the opposite ends of the U being brought and held together, in clamping mode, by a fastener which, as it tightens, draws the U-ends together around the rope and which, like the U, can be opened to fit over the rope initially; and with respective locating bars projecting one from each opposite outside surface of the U.One presently preferred way of putting the invention into practise will now be described with reference to the accompanying drawings.

Brief Description of the Drawings The drawings are all diagrammatic and they show between them the construction of several clamps embodying the invention.

In these drawings: Figure 1 and Figure 3 show in side elevation the initially flat stamped-out formations of the two co-operating halves of a first embodiment of the clamp; Figure 2 and Figure 4 show each of these two halves after it has been curved to its final form; Figure 5 shows the assembled clamp according to the first embodiment in perspective; Figure 6 shows the clamp in Figure 5 in end elevation; Figure 7 shows the nut which forms part of the clamp and which is also shown in Figures 5 and 6; Figure 8 shows a second embodiment of a clamp embodying the invention in end elevation around a wire rope; Figure 9 shows a third embodiment of a clamp embodying the invention in end elevation around a wire rope; and Figure 10 shows a front view of the clamp illustrated in Figure 8.

Description of the Preferred Embodiments The clamp shown comprises respective interlocking halves 11, 12 with respective locating bars 13 and 14 projecting from each opposite outside surface of the assembled clamp halves.

The bars 13 and 14 are welded onto the outside surfaces of the clamp halves when the clamp halves have been manufactured, bent to shape, and interlocked. They could alternatively be welded on, after the clamp halves have been bent to shape as shown in Figures 2 and 4, but before the two clamp halves are interlocked. Their construction, size and shape can vary as can the size and shape of the rest of the clamp to suit circumstances.

One clamp half 11 has a relatively large cut out 15 formed in one of its end regions and a correspondingly smaller rectangular cut out 16 formed adjacent its other end region. That other end region, referenced 17 in Figure 1, forms a tongued extension of the main part of clamp half 11 and the entire clamp half is initially stamped out flat from metal sheet.

Clamp half 12 similarly has two cut outs formed in it, the first one opening out onto its end face and being referenced 18, the second being an enclosed bounded U-shaped cut out and being referenced 19. Clamp half 12, like clamp half 11, is stamped out from an initially flat sheet of metal.

Both clamp halves are then bent to their respective side-view profiles shown in Figure 2 and Figure 4. In those states, the tongue 17 of clamp half 11 fits into and interlocks with, the cut out 19 of clamp half 12. The dimensions of the cut out 19 will be dependent on the dimensions of tongue 17. There is thus formed a basically U-shaped clamp which is hinged in the region of its bend and which can therefore be opened to allow it to be fitted over differing sizes of rope at a given region along the rope' 5 length without having to be slid along the rope from one end thereof.

The opposite ends of the thus-formed U are brought and held together, in clamping mode, by a fastener comprising a bolt 21 and nut 22. The bolt 21 has an externally screw threaded shank 23 projecting from a head 24 which, like the shank, is circular cylindrical and elongate; and which thus gives to the bolt overall a T-shaped apprearance. The nut 22 is hexagonal and is internally screw threaded to co-operate with the threaded shank 23 of the bolt 21.

The nut 22 also has a tapered underside region 25. In use, this underside region 25 engages a dished area around the periphery of the cut out 18. This dished area is referenced 26 in Figure 4 and is shown, by way of emphasis, in the scrap sectional view associated with Figure 4.

The head 24 of the bolt 21 is held captive in the curved region of clamp half 12 containing the cut out 15. The cut out allows the bolt shank 23 to span the projecting ends of the U-hinged region of the clamp. The corresponding cut out 18 in clamp half 12 receives the end region of the bolt shank 23 and, as just explained, accommodates the nut 22.

Because the U-halves 11 and 12 are flat in the regions where, in use, they embrace the wire rope (not itself shown in the drawings), then the rope-contacting surfaces of the U tend to flatten rather than to bite into the rope strands. Because the bolt 21 is effectively held captive in the clamp, it is not easily lost and this is particularly important in offshore settings where the presently described and illustrated embodiment is intended for use. Making the U from initially separate and flat stampings, rather than (for example) making it from one performed inherently resilient piece of metal, is not only efficient in a manufacturing context but it also avoids any fatigue-failure problems inevitably inherent in repeatedly flexed resilient units.

Other advantages will become apparent to those skilled in the field to which the invention relates. But it is worth mentioning specifically that, where the clamp secures a sling loop eye, the "Tyrap" previously mentioned can be done away with because the protruding bars 13 and 14 prevent the eye from inadvertently slipping over the clamp.

It is also worth pointing out that the so-called bulldog clamp (the known U-shaped clamps first reviewed under the art known to the Applicants) often have to be cut off whereas the clamp described and illustrated is re-usable.

The second embodiment is shown in Figure 8 and comprises respective interlocking halves 30, 31 with respective locating bars 32 and 33 projecting from each opposite outside surface of the assembled clamp halves. The construction of this second embodiment is substantially equivalent to the first embodiment except in the provision for, and construction of, the fastener.

In this embodiment the ends 34 and 35 of the halves 30 and 31 respectively are substantially planar and each include a longitudinal slot (not shown). The ends 34 and 35 are so arranged that the slots are substantially equivalently spaced on each end so that a bolt 36 can be inserted through the two slots so that a nut 37 can be screwed onto the threaded end of the bolt 36 to tighten the clamp. A wire rope 38 is shown between the two halves 30 and 31.

The third embodiment, illustrated in Figures 9 and 10, also comprises respective interlocking halves 40, 41 with respective locating bars 42 and 43 projecting from each opposite outside surface of the assembled clamp halves 40 and 41. A wire rope 44 is shown clamped between the two halves 40 and 41. Again the clamp is substantially equivalent to the first and second embodiments described herein except for the provision for, and construction of, the fastener.

In this embodiment at the ends 45 and 46 of arms 40 and 41 respectively additional stampings are made to produce two slots 47 on each arm. These slots 47 are shown more clearly in Figure 9.

The slots 47 are vertically spaced on each of the ends 45, 46 and the slots 47 on end 45 are aligned with substantially equivalent slots 47 on end 46.

To fasten the halves 40, 41 together a metal "Tyrap" (trade mark), shown diagrammatically in Figure 8, is passed through each aligned pair of slots 47 and subsequently tightened. To release the clamp both the wTyrapsw are cut off.

This embodiment still prevents the clamp from cutting into the wire rope 44 whilst also providing a quick, convenient and cheap method of fastening.

Claims (4)

1. A wire rope clamp, shaped like a 'U' to embrace the rope's periphery, and with the rope-contacting inside surfaces of the U being wide enough to tend to flatten, rather than to bite into, the rope strands; the U being hinged in the region of its bend to allow it to be fitted over the rope at a given region along the rope's length without having to be slid along the rope from one end thereof; the opposite ends of the U being brought and held together, in clamping mode, by a fastener which, as it tightens, draws the U-ends together around the rope and which, like the U, can be opened to fit over the rope initially; and with respective locating bars projecting one from each opposite outside surface of the U.

2. A clamp according to Claim 1 and in which the U is constructed from two halves interlocking at one corresponding end to form the hinged U-bend and appropriately configured at the other end to accommodate the fastener.

3. A clamp according to Claim 2 or Claim 1 and in which the fastener is held captive, when opened, in the clamp.

4. A wire rope clamp substantially as described herein with reference to and as illustrated in Figures 1 to 7, Figure 8 or in Figures 9 and 10 of the accompanying drawings.