GB2253452A - Pipe couplings - Google Patents

Abstract

The invention provides a pipe coupling 1 comprising an annular sleeve 2 arranged in use at a free end thereof to overlie an end of a plain ended pipe 6, 7 to be connected by the coupling 1; an annular elastomeric sealing gasket 22 disposed within and adjacent the free end of the sleeve member 3, 4 and arranged in use to be compressed and sealed between the sleeve 2 and the outer peripheral wall of the pipe 6, 7 to be connected, the sleeve member 3, 4 adjacent its free end being radially movable with respect to its axis; clamping means 16, 17, (18), 19, (20), 21 located about the sleeve 2 adjacent the free end thereof and arranged for radial tightening upon the sleeve 2, whereby the free end of the sleeve 2 is urged radially inwardly, providing a compressive force on the annular gasket 22 located therewith in. <IMAGE>

Description

Pipe Coupling This invention reiates to pipe couplings, and more particularly to pipe couplings of the kind adapted to connect together plain ended pipes to other pipes, such pipes often being arranged to carry fluids at a pressure above atmospheric.

It is to be understood that the expression "pipe" as used herein includes pipes and tubes as such and also pipe-like members and fittings for use in pipework such as bends, elbows, "T" connectors, flange adapters and parts and devices adapted to be fitted by pipe-like parts to pipework such as valves and pumps.

Pipe couplings of the kind referred to above commonly comprise an annular sleeve member for overlying the end of a plain ended pipe, a sealing gasket disposed in use in an annular disposition at one end of and within the sleeve member about the plain ended pipe, and compression means for compressing in use the sealing means between the sleeve and the pipe to be connected by the coupling to prevent leakage at the coupling.

Such pipe couplings can be formed, for example, of metal such as steel or cast iron, or plastics material, the gaskets being of an appropriate elastomeric material Pipe couplings of this kind are often used for connecting two abutting plain ended pipes, in which case sealing gaskets and compression means are provided at both ends of the sleeve member.

Pressure pipe couplings to date have relied upon the use of a rigid sleeve with a bore larger than the largest pipe to be coupled and sealed thereby, and a rubber based gasket configured to fill the gap between the pipe and the sleeve, the sealing force being usually provided by axially moveable compression flanges having axially effected tightening means which, by means of wedges or tapers for example move a considerable volume of the rubber based gasket radially inwardly from the sleeve to engage upon the pipe to be sealed.

Whilst such pipe couplings are widely used, historically a particular size coupling has only been capable of dealing with a limited outside diameter range of plain ended pipes because of the constraints imposed in attempting to ensure compression of the annular sealing gasket between the inner peripheral wall of the sleeve and the outer peripheral wall of the plain ended pipe to be connected and sealed by means of the coupling.

It is an object of the present invention to overcome or at least significantly reduce the above-mentioned disadvantage.

In accordance with the invention there is provided a pipe coupling comprising an annular sleeve arranged in use at a free end thereof to overlie an end of a plain ended pipe to be connected by the coupling; an annular elastomeric sealing gasket disposed within and adjacent the free end of the sleeve member and arranged in use to be compressed and sealed between the sleeve and the outer peripheral wall of the pipe to be connected, the sleeve member adjacent its free end being radially movable with respect to its axis; clamping means located about the sleeve adjacent the free end thereof and arranged for radial tightening upon the sleeve, whereby the free end of the sleeve is urged radially inwardly, providing a compressive force on the annular gasket located therewithin.

It will be appreciated that by means of the invention pipes of a wide range of outside diameters can be accommodated and sealed within the coupling of the invention by appropriate tightening and consequent radial movement of the clamping member to compress the gasket between the radially flexible sleeve and the pipe to be sealed and connected by the coupling.

The sealing gasket means may comprise a tubular elastomeric lining to the sleeve member.

The overall clamp band is an important aspect of the coupling of the present invention and may consist of an annular ring in one or more segments which may be joined by bolts for example lying tangentially or circumferentially to the coupling body. The band may be made from semi-rigid material to allow its radius of curvature to change during tightening whereby to maintain an even pressure on the sealing gasket within the coupling.

The radial moveability of the sleeve end may be provided by forming the sleeve end into axially outwardly extending separate digits which may be increasingly separated from each other towards their outer ends.

Alternatively, for example, the sleeve end may be formed into axially extending corrugations along its length and extending therearound.

The moveable sleeve ends may be flexible. To hold the clamping means about the radially moveable sleeve end, the outer periphery thereof may be provided with a retaining groove, or may, at or adjacent its axial extremity, be provided with at least one shoulder around its periphery against which the clamping means may abut.

The coupling of the invention may be provided for connecting two abutting plain ended pipes and may therefore be radially moveable at each end of the sleeve and be provided with sealing gasket means at each end, together with clamping means about the radially moveable ends.

Where a double ended sleeve is provided for connecting two abutting plain ended pipes, this may, for example, be a single integral sleeve or may be in the form of two separate half sleeve members abutting each other and supported radially outwardly thereof by means of an outer annular collar.

The invention includes within its scope a pipe joint comprising a coupling as hereinabove defined mounted upon at least one plain ended pipe.

In order that the invention may be more readily understood one embodiment thereof will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is an end view of a coupling and joint in accordance with the invention showing its application on two diameter pipes at the upper and lower halves thereof; and Figure 2 is a side view of the coupling and joint of Figure 1.

Referring now to the drawings it will be seen that the pipe coupling 1 comprises a two-part sleeve 2 formed of a semi-rigid plastics material, the two sleeve members 3,4 being reinforced where they abut one another by means of an outer rigid plastics collar member 5 to prevent any radial outward distortion of the sleeve 2 under pressure from within pipes 6,7 to be coupled. The two sleeve members are permanently joined to the collar.

Each end of the sleeve 2 is provided with a multiplicity of tapered axial slits 10,11 defining a plurality of digits 12,13 at the two sleeve ends. The sleeve ends and digits 12,13 themselves in their relaxed condition as shown in the upper half of the Figures flair radially outwardly so as to provide axially inwardly of the flaring a shoulder 14,15 at the axial extremeties of the sleeve.

Disposed behind the shoulders 14,15 at the axial extremities of the sleeve 2 are two-part generally semicircular clamp members 16,17 connected together by means of bolts 18,19 having nuts 20,21 which may be tightened upon the digitised ends of the sleeve 2.

Disposed within the sleeve 2 is a tubular elastomeric rubber based sealing gasket 22 which lines the sleeve and bridges the slits 10,11 between the digits 12,13 at the ends of the sleeve. The gasket may (in a manner not shown) have integral with it or be supported by semi-rigid reinforcements to ensure effective sealing across the slits 10,11. In practice sealing action of the gasket is improved by providing a textured radially inner surface 14 on those parts thereof which contact the pipes to be connected. The axial ends of the gasket 22 flair outwardly, in their relaxed condition as shown in the upper halves of the drawings, and are shaped so that a part of the textured inner surface 14 of the gasket 22 is directly underneath the clamp band 17 throughout the full range of radial movement of the sleeve ends.

In the arrangement of the coupling illustrated the clamp band is in the form of two semi-circular segments 23,24 joined by the tangetial bolts 18,19 passing through appropriate bores in outwardly extending lugs 25,26, tightenings being by means of the 20,21 nuts on the bolts.

The band segments 23,24 are made from a semi-rigid plastics material to allow its radius of curvature to adjust during tightening upon and radial contraction of the digits 12,13 of the sleeve ends. Similarly, each band segment is provided with a semi-circular inner configuration in order to maintain a radial force on the sleeve 2 during tightening as the digits 12,13 of the sleeve bend radially inwardly within it. Again, provision is made for the changing angle of the bolts 18,19 within their lugs 25,26 during such tightening and radial contraction by means of circular seated washers 28 fitted to the bolts. These features ensure optimum efficient use of the force provided by the tightening bolts, thereby minimising the torque required to contract the coupling upon the pipe to be connected with the necessary seal.As can be seen by comparing the upper and lower parts of the Figures, showing the coupling upon a larger pipe 6 and a smaller pipe 7 respectively, despite significant differences of size of pipe within the coupling, a totally satisfactory seal can be provided between the pipe and coupling by appropriate tightening of the clamp band 17 to contract radially the digits 12,13 of the sleeve ends.

It will be appreciated that the coupling hereinabove described and illustrated can be used to effect a seal onto pipes of a wide variety of outer diameters and to pipes of any reasonably rigid material, Again, it will be appreciated that by use of the bolted clamp bands at each end of the sleeve, each end of the coupling can be operated independently so ensuring equai sealing for any combination of pipe sizes connected by the coupling.

The coupling illustrated and described above is shown as one for connecting together two to pipes as such, but could equally well be manufactured as a pipe adaptor with a flange or a fitting at one end, and with the radially contractable digits and clamp band of the invention at the other end.

More generally, it is to be understood that the foregoing is merely exemplary of pipe couplings and joints in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention.

Claims (1)

1 A pipe coupling comprising an annular sleeve arranged in use at a free end thereof to overlie an end of a plain ended pipe to be connected by the coupling; an annular elastomeric sealing gasket disposed within and adjacent the free end of the sleeve member and arranged in use to be compressed and sealed between the sleeve and the outer peripheral wall of the pipe to be connected, the sleeve member adjacent its free end being radially movable with respect to its axis: clamping means located about the sleeve adjacent the free end thereof and arranged for radial tightening upon the sleeve, whereby the free end of the sleeve is urged radially inwardly. providing a compressive force on the annular gasket located therewithin.

2 A coupling as claimed in claim 1 wherein the sealing gasket comprises a tubular elastomeric lining to the sleeve member.

3 A coupling as claimed in claim 1 or 2 wherein the clamping means comprises an annular ring in one or more segments.

4 A coupling as claimed in claim 3 including a plurality of segments to the clamping means wherein the plurality of segments are joined by bolts lying tangentally or circumferentially to the coupling body.

5 A coupling as claimed in claim 3 or 4 wherein the annular ring is made from semi-rigid material to allow its radius of curvature to change during tightening whereby to maintain an even pressure on the sealing gasket within the coupling.

5 A coupling as claimed in any one of the preceding claims wherein radial movability of the sleeve is provided by forming the sleeve end into axially outwardly extending separate digits.

7 A coupling as claimed in claim 6 wherein the digits are increasingly separated from each other towards their outer end.

8 A coupling as claimed in any one of claims 1 to 5 wherein the sleeve end is formed into axially extending corrugations along its length and extending therearound.

9 A coupling as claimed in any one of claims 5. 7 or 8 wherein the movable sleeve ends are flexible.

10 A coupling as claimed in any one of the preceding claims wherein the clamping means is held about the radially movable sleeve end by providing the outer periphery thereof with a retaining groove or at least one shoulder around its periphery against which the clamping means abut.

11 A coupling as claimed in any one of the preceding claims for connecting two abutting plain ended pipes. and being radially movable at each end of the sleeve and provided with a sealing gasket means at each end together with clamping means about the radially movable ends.

12 A coupling as claimed in claim 11 wherein the double ended sleeve is provided as a single integral sleeve. or as two separate half sleeve members abutting each other and supported radially outwardly thereof by means of an outer annular collar.

13 A pipe coupling substantially shown in and as hereinbefore as described with reference to the accompanying drawings.

14 A pipe joint including a coupling as claimed any one of the precedina claims.