GB2454526A

GB2454526A - Pipe clamp with radially movable cams

Info

Publication number: GB2454526A
Application number: GB0722146A
Authority: GB
Inventors: Rowan Warrick Patterson
Original assignee: UWG Ltd
Current assignee: UWG Ltd
Priority date: 2007-11-09
Filing date: 2007-11-09
Publication date: 2009-05-13
Also published as: GB0722146D0

Abstract

A connector 5 for connecting a component 18, 20 to a tubular member 10 comprises a collar 16 with a number of equally spaced dogs 24 mounted in the collar which can be moved radially to make clamping contact with the tubular member 10. A clamp ring 28 surrounds the collar and has an inclined cam face 38 which contacts the outward faces 36 of the dogs 24. The lamp ring 28 is pulled axially onto the collar using bolts 32 and nuts 34, which causes the cam faces 36, 38 to engage and force the dogs 24 inwards to clamp on the tubular member 10. The connector may be used underwater to connect structural beams to vertical columns underwater, to brace the columns against each other. The use of clamps, instead of welding, does not affect the structural integrity of the columns.

Description

Connector This invention relates to a connector for clamping a tubular member around another tubular member.

It is known to attach a component to a tubular pipe or the like by welding the component directly to the pipe wall or by welding a bracket or lug to the pipe wall and then attaching the component to the bracket or lug. However placing a weld on the pipe wall will always have the potential to interfere with the structural integrity of the pipe. If the pipe wall can be pierced, it may be possible to attach a component by passing a fastening through the pipe, but this also interferes with the strength of the pipe.

According to the invention, there is provided a connector for clamping a component to a tubular member, the connector comprising a collar adapted to surround the tubular member with a small spacing, a plurality of radially movable dogs mounted in the collar and a ring surrounding the collar, wherein the dogs each have an inclined end face and the ring has an oppositely inclined internal surface such that when the ring is moved axially relative to the collar :. 20 and the dogs, the dogs are forced inwardly to engage the tubular member and :..::: to grip the tubular member. S...

By clamping to the outer surface of the pipe, the integrity of the pipe is maintained. Furthermore, the clamp can be located in any position along the length of the tubular member and can be released and repositioned to wherever the connector may be required.

A cam action is obtained between the ring and the dogs.

There should be at least three dogs, and preferably more, for example eight.

The dogs should be equally spaced around the axis of the collar.

The inward facing faces of the dogs can have projections or ribs extending from the faces to make initial contact with the tubular member, to enhance the frictional grip of the dogs on the tube.

To clamp the connector, threaded fasteners are mounted between the clamp ring and the collar. The fasteners may be threaded studs fixed to either the ring or the collar and passing through holes in the other of the ring or collar, with nuts which can be tightened onto the studs. Alternatively bolts may pass through holes in one of the two parts, into threaded bores in the other part.

Tightening of the fasteners draws the ring towards the collar and forces the dogs inwardly.

To prevent the clamp from being activated until it has been correctly positioned, jacking screws can be provided between the clamp ring and the collar to support the clamp ring on the collar at a position where the clamp ring does not force the dogs inwardly.

In most cases, the collar will be circular in cross section, for clamping around a n... 20 right cylindrical tubular member. Also the connector will probably be of metal, for clamping to a metal tubular member. The components should be chosen to * be capable of deployment underwater.

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* The connector of the invention can be used in a clamp assembly comprising *:::: 25 two connectors, the collars of which are located at opposite ends of asleeve :. which joins the collars. Structural beams can then be welded to the sleeve between the connectors.

The invention also extends to an underwater structure comprising a plurality of columns linked by a frame or frames extending between the columns, wherein -3-.

the or each frame includes collars received around the columns, structural members extending between the collars and a connector as set forth above associated with at least one of the collars.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figures 1 and 2 show part of a connector according to the invention, in cross-section, with the connector being in the unclamped position in Figure 1 and in the clamped position in Figure 2; Figure 3 is a plan view of the connector; Figure 4 is an exploded view of the connector; and Figure 5 shows one application of a connector in accordance with the invention.

Figure 1 shows a view of one side of a tubular member or pipe 10, showing the n... 20 pipe's maximum diameter at 12 and the minimum diameter at 14. These two diameters represent the tolerance extremes on the pipe diameter. A connector is fitted on the pipe and has a collar 16 which surrounds the pipe. The connector, in the position shown in Figure 1, can move freely up and down the length of the pipe 10. As shown in Figures 1 and 2, the collar 16 has welded-on *::::* 25 extensions at 18, 20 by means of which other components can be attached through the connector to the pipe, as will be described below with reference to Figure 4.

The collar 16 has a number of radial bores 22 around the circumference, and in each of these radial bores a cam block or dog 24 is received. Each dog 24 can move radially in the direction indicated by an arrow 26.

A circular clamp ring 28 surrounds the collar and is attached to the collar through threaded studs 30. Nuts 32, 34 are screwed onto the threads of the stud 30, and by tightening down the upper nut 34, the ring 28 can be drawn down towards the collar 16, to the position shown in Figure 2 where cam faces 36, 38 on the dog 24 and ring 28 respectively come into contact with the result that the dog 24 is driven radially inwards to make contact with the surface of the pipe 10 (see Figure 2).

To enhance the vertical resistance/grip of the dogs on the pipe, knurling or radial profiles of V-or half-round section can be machined on the face of the dogs 24. By this means it is possible to improve vertical resistance above that of preload and friction, by the small indentation that will be achieved on the pipe 10.

It will be seen from Figure 3 that there are a series of equi-spaced stud bolts 30 ... 20 regularly spaced round the clamp ring 28, and each aligned with the position of *...

one of the dogs 24. Figure 3 also shows four regularly spaced jacking screws 42. These screws hold the clamp ring 28 in the Figure 1 position out of S.....

* engagement with the dogs 24, until the connector is to be set in position. At this 5....

* S stage the jacking screws can be released so that the clamp ring 28 will initially *. 25 fall under its own weight into contact with the cam face 36 of the dogs 24, and then can be further tightened to force the dogs against the pipe wall by tightening the nuts 34.

Figure 4 Figure 5 shows one application of the invention, where two connectors A and B, with their respective collars 16 are attached at opposite ends of an elongate sleeve 180. The sleeve 180 is a tube of diameter slightly larger than that of the pipe 10. Structural beams 50 are welded to the sleeve 180 and extend between the sleeve 180 and similar sleeves on adjacent pipes 10. However any alternative component can be similarly attached to the sleeve 180 which itself takes very little load, and will not therefore be significantly reduced in strength by having weldments on its surface.

An assembly incorporating a number of collars 180 joined by beams 50 as shown in Figure 4 can be lowered over a suitable spaced array of pipes 10, with a flared end 52 helping to locate each sleeve over the top end of one of the pipes 10. The assembly shown in Figure 5 is to be located at the top of the pipes 10 and therefore the top ends of the sleeves 180 are provided with caps 54 which will sit on the top of the pipes 10 and limit downward movement.

The connector is particularly designed for use in underwater applications and where connections have to be made between oil field pipes or legs extending from the seabed to the sea surface. The pipes 10 in such applications will be ** 20 metal, and the dogs will also be metal, so that a metal to metal contact is made, S...

between the faces of the dogs and the pipe, and some deformation (elastic or plastic) can take place locally to assist the grip of the connector on the pipe. In most applications, all the parts of the connector will be metal.

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Claims

Claims 1. A connector for clamping a component to a tubular member, the connector comprising a collar adapted to surround the tubular member with a small spacing, a plurality of radially movable dogs mounted in the coltar and a clamp ring surrounding the collar, wherein the dogs each have an inclined end face and the ring has an oppositely inclined internal surface such that when the ring is moved axially relative to the collar and the dogs, the dogs are forced inwardly to engage the tubular member and to grip the tubular member.
2. A connector as claimed in Claim 1, wherein there are at least three dogs.
3. A connector as claimed in Claim 2, wherein there are eight dogs.
4. A connector as claimed in any preceding claim, wherein the inward facing faces of the dogs have projections extending from the faces to make initial contact with the tubular member.
5. A connector as claimed in any preceding claim, wherein threaded bolts : 20 are mounted between the clamp ring and the collar, so that tightening of the e.

bolts draws the ring towards the collar and forces the dogs inwardly.
6. A connector as claimed in any preceding claim, wherein jacking screws are provided between the clamp ring and the collar to support the clamp ring on S...

:.. 25 the collar at a position where the clamp ring does not force the dogs inwardly.
7. A connector as claimed in any preceding claim, wherein a component to be clamped to the tubular member is attached to the collar.
8. A connector as claimed in any preceding claim, wherein the collar is circular in cross section, for clamping around a right cylindrical tubular member.
9. A clamp assembly comprising two connectors as claimed in any preceding claim connected at opposite ends of a common collar, with structural beams welded to the collar between the connectors.
10. A clamp assembly as claimed in any preceding claim for clamping a component to a metal tubular member, wherein the collar, the clamp ring and the dogs are all of metal
11. An underwater structure comprising a plurality of columns linked by a frame extending between the columns, wherein the frame includes collars received around the columns, structural members extending between the collars and a connector as claimed in any one of Claims I to 8 associated with at least one of the collars.
12. A connector substantially as herein described with reference to the accompanying drawings. S... * S S...

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