GB2255131A - Wire rope clamp - Google Patents

Abstract

A wire rope clamp, shaped like a "U" to embrace the rope's periphery, and with the rope contacting inside surface 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 been slid along the rope from one end thereof; the opposite ends of "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 characterised by locating bars 50 forming an angle substantially less than 180 DEG with one another. <IMAGE>

Description

CLAMP Background to the Invention In the applicant's previous UK Patent Application number 90 20880.2 a clamp, specifically a wire rope clamp, is disclosed having two locating bars projecting one from each opposite outside surface of the "U".

UK Patent Application number 90 20880.2 (Critoph, Brown and Olympia Testing (East Anglian) Limited), was published on 31 July 1991 under GB 2 240 359 A and this specification is reproduced here.

Wire rope clamps, particularly in the offshore industry, are know 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-inpostion point of view, they do tend to damage the ropes; and to secure a loped sling-eye in place they need further securing, for example by an electrical cable "Tyrap" interwoven through the eye and the c .

We believe that the clamp diBsed in this present UK patent application is a further embodiment of the clamp, which has been cEsclcsed already, and, that this further embodiment does fall within the scope of the Claims of UR Patent Application number 90 20880.2.

The present invention has, in its own right, substantial advantages over and above the clamp previously dismissed.

Summary of the Invention According to the present invention there is 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 hite into, the rope strands; the "U" being hinged in the region of its bend to allow it to be felted 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 characterised by locating bars forming an angle su)=aZy less than 180 with one another, Preferably, the respective locating bars project one from each opposite outside surface of the "U': Preferably, there are three or more locating bars each equally space radially about the outside surface of the "U".

The "U" maybe constructed from two halves lnterocking at one cormsponding end to form the hinged "U"bend and appropriately configured at the other end to accommodate the fastener.

Preferably, the fastener is had captive, when opened, in the clamp.

Brief Description of the Drawings Figures 1-10 of the accompanying drawings are identical to figures 110 of specification GB 2 240 359 A. Figure 11 shows the features in which the preferred embodiment of the present invention differs from GB 2 240 359 A. The features shown by each figure are repeated here for completeness.

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 fist embodiment in respective; 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 ciew of the clamp iLlustrated in Figure 8.

Figure 11 shows a wire roped clamp embodying the invention in which there are three locating bars equally spaced radially about the outside surface of the "U".

Descnption of the Preferred Embodiments The present invention can be best described by initially repeating the description of the preferred embodiments from published UK Patent Application number GB 2 240 359 A.

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 a7ternah'vely be welded on, after the clamp halves have been bent to shape as shown in Figure 2 and 4, but before the two clamp halves are interiocked. Their construction, size and shape can vary as can the size and shape of the rest of the clamp to suit drnz stances.

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 aXacent its other end region. That other region, referenced 17 in Figure 1, forms a tongued extension of the main part of the damp half 11 and the entire damp half is initaLLy 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 Ushaped cut out and being referenced 19.

Clamp half 12, like damp half 11, is stamped out from an flat sheet of metal.

Both damp halves are then bent to their respective side-view profiles shown in Figure 2 and Figure 4. In those states, the tongue 17 of damp half 11 frets into and interlocks with, the cut out 19 of damp half 12. The dimensions of the cut out 19 will be dependant on the dimensions of tongue 17. There is thus formed a basically Ushaped damp 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's 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 damping mode, by a fastener compneing a bolt 21 and nut 22.

The bolt 21 has an externally screw threaded shank 23 projecting from a head 24 which, like the shrank, is circular cyjindracal and elongate; and which thus gives to the belt overall a T-shaped appearance. The nut 22 is hexagonal and is internally screw threaded to cho opiate with the threaded shank 23 of the belt 21.

The nut 22 also has a tapered underz;ide 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 damp half 12 containing the cut out 15. The cut out allows the bat shank 23 to span the projecting ends of the U-hinged region of the clamp. The corresponding cut out 18 in damp half 12 receives the end region of the bolt shank 23 and, as explained, accommodates the nut 22.

Because the U-halves 11 and 12 are flat in the region 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 hite into the rope strands. Because the bolt 21 is effectively held captive in the damp, 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 fatiguefailure problems inevztbly inherent in repeatedly flexed resilient units.

Other advantages wifl become apparent to those skilled in the fiord to which the invention relates. But is worth mentioning specifically that, where the damp secures a siing 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 damp.

It is also warth pointing out that the sFcalled bulldog damp (the known U-shaped damps first reviewed under the art known to the Applicants) often have to be cut off wheres the clamp described and illustrated is re-usable.

The second embodiment is shown in Figure 8 and comprises respective interiocking halves 30, 31 with respective locating bars 32 and 33 projecting from each opposite outside surface of the assembled damp 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 slats are substantially equivalently spaced on each end so that a balt 36 can be inserted through the two slots so that a nut 37 can be screwed onto the threaded end of the belt 36 to tighten the damp. A wire rope 38 is shown between the two halves 30 and 31.

The third embodiment, illustrated in Figure 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 damp halves 40 and 41. A wire rope 44 is shown damped between the two halves 40 and 41. Again the damp 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 siots 47 on each arm. These sloths 47 are shown more clearly in Figure 9.

The stots 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 diagr:ammatically in Figure 8, is passed through each alloned pair of slots 47 and sesequently tightened. To release the clamp both "Tyraps" 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.

Referring now to Figure 11, this shows the present invention in detail with three or more locating bars 50 each equally spaced radially about the outside surface 51 of the "U". The description which follows concentrates on the feature of the new embodiment which is different from those of Figure 1-10.

In the embodiments shown in Figure 1-10 there are two locating bars 13 and 14. In the new embodiment of Figure 11, by contrast, there are three or more locating bars 50 sited on the outside surface of the clamp.

The applicant found that in use the clamp which had two locating bars 13 and 14 would tend to be rotated by the sling and the sling loop eye would pass over the two locating bars 13 and 14. This unexpected occurrence resulted in the applicant seeking to overcome the problem and developing the present invention.

The new embodiment, in which there are three or more locating bars 50 sited on the outside surface of the clamp, overcomes the problem encountered with the previous embodiment in the following way. As the clamp is rotated by the sling and the sling loop eye passes over one of the locating bars 50, the sling loop eye engages a second locating bar 50, so that the clamp does indeed secure the sling loop eye.

Claims (6)

Claims

1 A wire rope clamp, shaped like a "U" to embrace the rope's periphery, and with the rope contacting inside surface 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 been slid along the rope from one end thereof; the opposite ends of "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 characterised by locating bars forming an angle substantially less than 180 with one another.

2. A clamp according to Claim 1 and in which the respective locating bars project one from each opposite outside surface of the "U".

3. A clamp according to Claim 2, in which there are three or more locating bars each equally space radially about the outside surface of the "U".

4. A clamp according to Claim 3 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.

5. A clamp according to Claim 4 and in which the fastener is held captive, when opened, in the clamp.

6. A clamp substantially as described herein with reference to and as illustrated in Figures 1-7, Figure 8 or in Figures 9 and 10 or in Figure 11 of the accompanying drawings.