GB2144795A - Pipe clamp - Google Patents

Abstract

The invention provides a pipe clamp having a generally C-shaped band terminating in a pair of lugs 2,3, the lugs being arranged to be drawn together by bolt means 10 acting at each side of the band. Various forms of lug are described. <IMAGE>

Description

SPECIFICATION Pipe Clamp The invention relates to pipe gripping devices for flexible pipes or for rigid pipes such as exhaust pipes.

Pipe clamps are known which comprise a Cshaped flexible band with the ends turned back at 90 to form lugs for drawing together by means of a bolt or the like for exerting gripping force on a pipe encircled thereby. Such clamps, however, have limited mechanical strength and the lugs tend to become distorted. The present invention arose out of a requirement for more substantial gripping devices which were at the same time simple to manufacture and operate.

According to the invention there is provided a pipe gripping device comprising a flexible band of C-configuration having lug means secured at each end thereof and projecting laterally of the band, and bolt means arranged at each side of the band for drawing the respective lug means towards one another. The band may be provided with an extension spanning the gap between the lug means.

Each lateral projection of each of the lug means may be bored for the passage of a bolt, and the bores in one of the lug means may be threaded.

The band may be a wire; alternatively, the band may be a flat strip of metal such as steel or of rubber or plastics, or it may be a strap of woven or braided fabric.

The lug means may be secured by looping the band around them, and the lug means may be rounded in transverse section where the band is looped round them.

The band may be an ended flat strip or strap and the terminal portions thereof may, after looping inwardly about the lug means, return to the portion of the band having the C-configuration and terminate in contact with the inner face of said C-configured portion. The terminal and C-configured portions may be secured together by welding. Alternatively or additionally, the inner face of the Cconfigured portion may be provided with a depression or a plurality of depressions in a lengthwise row, and the contiguous surface of the terminal portion may be provided with at least one mating projection.

The band may be an endless flat strip or strap, and the arrangement may be as if in an ended strip or strap as described above the two terminal portions extended towards and united with one another.

The bolt means may be bolts or screws and may be headed. Spacers may be provided to displace the heads from the lug means so as to avoid contact with the band by either the heads or tools for operating on the heads.

The invention will now be described by way of example and with reference to the accompanying drawings, of which: Figure 1 is a pipe clamp in plan view perpendicular to a hypothetical pipe being gripped thereby; Figure 2 is a side view of the clamp of Fig. 1; Figure 3 is a partial plan view of a pipe clamp in a second embodiment; Figures 4 and 5 are respectively side and end views of a clamp in a third embodiment; Figure 6 is a partial plan view of a fourth embodiment; Figures 7 and 8 are respectivley a partial plan view and a perspective view of a fifth embodiment; and Figure 9 is a perspective view of a sixth embodiment.

Referring firstly to Fig. 1, the pipe clamp comprises a narrow flat band 1 of flexible steel extending in a 10 generally C-configuration between two lugs in the form of short right cylindrical blocks 2, 3. The band loops around each of the blocks so that the terminal portions 4, 5 thereof lie within the C-configured portion of the band and are secured thereto by weld spots 6 adjacent the ends 7.

As shown in Fig. 2 the blocks 2, 3 are longer than the band 1 is wide, and each block is drilled at each side of the band to provide a bore 8, 9. The bores 8 are threaded internally. Bolts 10 having a thread corresponding to that of the bores 8 are passed loosely through the bores 9 and are screwed into the bores 8, the two bolts being parallel and lying one at each side of the band. A spacing plate 11 having a pair of holes 12 is provided to keep the heads 13 of the bolts 10 away from the band 1 so as to reduce the chance of damage to the band by the edge of the head or by a tool used to turn the head.

A length of strip steel similar to that of which the band 1 is formed is secured by spot weld 14 to the terminal portion 4 of the band and extends as a bridge 15 across the space between the blocks 2 and 3. When the clamp is fitted around a pipe as will be described below, the bridge 15 completes the encirclement thereof so that when the blocks 2, 3 are drawn together by screwing of the bolts 10 into the bores 8, the band 1 together with the bridge 15 generally conform to a circle of diminishing diameter.

To fit the clamp about a continuous pipe, the bolts 10 are unscrewed to remove them from the block 8 so that the band 1 can be bent in such a way as somewhat to flatten the C-shape. The blocks 2 and 3 are then spaced more widely apart so that the bridge 15 no longer spans the gap but allows the pipe to pass between it and the block 3.

The bolts 10 are then reintroduced into the block 8 and tightened so as to draw the blocks 2 and 3 closer together. There being two bolts, one at each side of the band, it is found in practice that it is easy to exert considerable tension on the band by screwing each of the bolts alternately and repeatedly through a small angular distance.

Turning to Fig. 3 wherein only one end of the Cshaped band is shown, it will be observed that the terminal portion 5 of the band, lying as in Fig. 1 to the inside of the C-shaped portion 1, is not however welded thereto. Instead, the terminal portion is provided, at spaced locations along its length with projections 16 in the direction of the C-shaped portion 1. The latter portion is provided with matching and similarly spaced depressions 17 into which the projection 16 can fit.

In use of a clamp of this embodiment, the clamp is arranged around a pipe in a manner similar to that referred to in connection with the Fig. 1 embodiment and the screw 10 engaged with a corresponding block (not shown) at the other end of the band. As longitudinal tension is exerted on the band 1, the capstan effect of the turning of the band about the block 3 is such as severely to limit the transmission of tension to the terminal portion 5, and at the same time the radial pressure exerted by the C-portion 1 upon the encircled pipe is such as to hold each projection 16 firmly in the corresponding depression 17 so as completely to resist any longitudinal tension in portion 5 and so prevent the slipping of the band about the block 3.

If necessary, the portions 5 and 1 may additionally be welded together, but in the embodiment shown there is no welding, and this provides a further advantage because as will be seen there are four depressions 17 and only two projections 16.

Provided that the material of the band is sufficiently flexible it can be slid around the block 3 so that the projections 16 fit into any adjacent pair of depressions 17, correspondingly lengthening or shortening the terminal portion 5 and shortening or lengthening the C-portion 1 to give a clamp of adjustable size. This possibility can be given very wide scope and indeed the depressions 17 may continue throughout the whole length of C-portion.

There may be more or fewer projections 16 in the terminal portion 5 as required. In the case of bands of metal or other suitable material the projections and the depressions, which are conveniently circular and along the centre line of the bands, may conveniently be made by punching. Where the band is of plastics or other suitable material, they may be formed by moulding.

In a variation of the embodiment of Fig. 3, not shown, an orifice is punched in that portion of the band 1 which lies contiguous with the terminal portion 5, and the terminal portion 5 is punched to provide a tongue projecting inwardly of the loop around the lug 3 and having its free end towards lug 3. When the clamp is assembled by looping the band around the lug 3, the tongue is inserted through the orifice so that the terminal and Cshaped portions of the band are connected thereby.

The above-mentioned embodiment may be varied in that the orifice may be formed in the terminal portion 5 and ghe tongue in the contiguous portion of the C-shaped portion of the band.

If, in the embodiment shown in Fig. 1, the spacing element 11 were to be omitted there would be a danger that the head 13 of the bolts 10, or a spanner or other tool applied to the head, could, an turning, catch the band 1 and damage it or be damaged by it. As an alternative to providing the spacing element 11, there is shown in Figs. 4 and 5 a lug block 18 having an intermediate portion 19 of circular cross-section or at least rounded at the face 20 by which it engages the band 1. At each side of the band the block 18 extends into two pil Jars 21 so that the head 13 of a bolt 10 which passes through each of the holes 22 is kept clear of the band 1 and of the underlying terminal portion 5.

Fig. 6 shows an embodiment in which the band is of round wire wrapped about cylindrical lugs 2, 3 so that each of the terminal portions 23, 24 extend across the gap between the lugs.

In the embodiment shown in Figs. 7 and 8, the encircling band is of round wire of larger diameter, and the ends of the band are bent at positions 25, 26 so that their terminal portions 27, 28 are sub stantiajly parallel to one another. The cylindrical lug blocks 29, 30 are provided with central diametral bores 31 for receiving the respective terminal portions and, to each side, perpendicular diametral bores 32 for receiving the bolts 10.

As an alternative to bending the wire forming the band as in Fig. 7, the bores 31 in the lug blocks 29,30 may be inclined to correspond to the angle of approach of the terminal portions 27, 28 of the wire. The bores may be initially formed sufficiently large to enable the wires to be inserted therein readily, but after insertion of the wire the bores may be diminished by pressing the blocks so that the wire is gripped therein. Moreover, the wire is arranged to project at its free ends beyond the blocks, and those free ends are swaged further to prevent the wire being pulled out of the bores when tension is applied to the band.

The blocks 29 and 30 may be used interchangeably with those of other embodiments such as the embodiment of Fig. 6 and that of Fig. 9 now to be described, albeit that in the other embodiments the central holes 31 are not employed. As shown in Fig. 9, wherein the bolts 10 are shown removed entirely from lug block 3, the band 33 is an endless strip or strap, for example of rubber, plastics or fabric or other textile material, looped at diametrically opposed positions 34, 35 to provide an outer C-shaped portion 36 and an inner C-shaped portion 37. The blocks 2, 3 are passed through the loops at positions 34, 35 so that a bolt 10 can be passed through holes 8, 9, located therein at either side of the band 33.

Whilst the appended claims seek to define the present invention as envisaged by the applicant at the time of submitting this application, the applicant reserves the right within the law to claim as an invention in general or specific terms, whether by way of divisional application or otherwise, any feature, method and/or aspect or any combination of features, methods and/or aspects disclosed herein which is or are subsequently identified to be inventive, and regardless of whether, in the case of a combination as aforesaid, the features, methods and/or aspects are disclosed individually in a single one of or in respective embodiments disclosed herein.

Claims (10)

1. A pipe gripping device comprising a flexible band of C-configuration having lug means secured at each end thereof and projecting laterally of the band, and bolt means arranged at each side of the band for drawing the respective lug means towards one another.

2. A device according to Claim 1 wherein the band is provided with an extension spanning the gap between the lug means.

3. A device according to Claim 1 or Claim 2 wherein each lateral projection of each of the lug means is bored for the passage of a bolt.

4. A device according to any one of Claims 1-3 wherein the lug means are secured at least in part by looping the band around them.

5. A device according to any one of Claims 1-4 wherein the band is a wire.

6. A device according to any one of Claims 1-4 wherein the band is a flat strip or a strap

7. A device according to Claim 6 wherein the terminal portions of the strip or strap may, after looping inwardly about the lug means, return to the portion of the band having the C-configuration and terminate in contact with the said C-configured portion.

8. A device according to Claim 7 wherein the terminal and C-configured portions are secured together by welding.

9. A device according to either of Claims 8 or 9 wherein the inner face of the C-configured portion is provided with a depression or a plurality of depressions in a lengthwise row, and the contiguous surface of the terminal portion are provided with at least one mating projection.

10. A pipe gripping device substantially as described with reference to any of the accompanying drawings.