GB2246396A - A through flow coupler - Google Patents

Abstract

A through flow coupler comprises two parts 10 and 11 having intercommunicating passages therein so that fluid can flow through the two pants. Sealing means, e.g. elastomeric seal 20, provides a fluid tight seal between the two parts when the two parts are held together. Pressure sensitive means, which may for example comprise a frangible ring 15, holds the two parts together when the fluid pressure is below a certain value and allows the two parts to move relative to one another so that fluid can escape from the passages means and relieve pressure therein when the fluid pressure within the passages means exceeds said certain value. Also, separation prevention means, e.g. flanges 17 and 24, are provided to prevent total separation of the two parts when the pressure sensitive means allows the two parts to move relative to one another. <IMAGE>

Description

A Through Flow Coupler This invention relates to a through flow coupler which also operates as a pressure relief device.

It is known to use pressure relief devices, such as yield valves, in pneumatic and hydraulic circuits. Yield valves can be made to operate at precise pressures and are relatively expensive, particularly when a large number are required in an installation.

There are numerous circumstances in which the operating pressure of a pressure relief device is not critical and the present invention seeks to provide such a device which is cheaper to make than a conventional yield valve and which is incorporated in a through flow coupler.

According to one aspect of the invention, there is provided a through flow coupler comprising two parts having intercommunicating passage means so that fluid can flow through the two parts, sealing means for providing a fluid tight seal between the two parts when the two parts are held together, pressure sensitive means for holding the two parts together when in use the fluid pressure within said passage means is below a certain value and for allowing the two parts to move relative to one another so that fluid can escape from the passage means and relieve pressure therein when in use the fluid pressure within said passage means exceeds said certain value, and means preventing total separation of the two parts when the pressure sensitive means allows the two parts to move relative to one another.

Preferably, said pressure sensitive means comprises frangible means breakable when the fluid pressure within said passage means exceeds said certain value. The frangible means may be in the form of an annular or part annular member fixed with respect to one of the two parts and engageable by a projection, e.g. an annular flange, fixed with respect to the other part.

In this case, the separation preventing means may comprise the projection fixed with respect to the said other part and a further projection, e.g. an annular flange, fixed with respect to said one part. Also, the first-mentioned projection may be on a sleeve releasably secured to the said other part, such as by a U-shaped member whose arms enter a pair of parallel tangential holes in the sleeve to engage a groove in the said other part.

alternativeiy, said pressure sensitive means may be some form of resilient, collapsible or releasable means.

Preferably, the sealing means includes an elastomeric sealing member carried by one of the two parts.

Typically, the device is in the form of a hose coupling for use in an hydraulic or pneumatic line.

According to a second aspect of the invention, there is provided a through flow coupler comprising a tubular part having a through passage therein, a sleeve mounted about, and projecting axially beyond, one end of the tubular part, means for connecting the part of the sleeve which projects beyond said one end of the tubular part to a further tubular part which is in use sealingly engageable with the first mentioned tubular part, pressure sensitive means for preventing relative axial slidable movement of the first mentioned tubular part and the sleeve when in use fluid pressure within the through passage is below a certain value and for allowing the sleeve to slide axially relative to the tubular part when in use the fluid pressure in the through passage exceeds said certain value, and means preventing total separation of the tubular part and the sleeve when the pressure sensitive means allows the sleeve to slide axially relative to the tubular part, the arrangement being such that when in use the sleeve is connected to said further tubular part, the further tubular part sealingly engages with the first mentioned tubular part unless the pressure sensitive means allows the sleeve and first mentioned tubular part to slide axially relative to one another when fluid can escape between the two tubular parts and relieve pressure within the two tubular parts.

The device has particular application in mine roof supports and, therefore, in a third aspect the invention provides a mine roof support equipped with one or more couplers according to the first or second aspect of the invention.

The invention will now be more particularly described, by way or exampleS with reference to the accompanying drawings, in which: Figure 1 is a part sectional view of one embodiment of a through flow coupler according to the present invention, and Figure 2 is a view similar to Figure 1 but shows the coupler after the frangible ring has sheared, Figure 3 is an exploded perspective view of the coupler shown in Figure 1, and Figure 4 is a plan view of an alternative frangible member.

Referring now to the drawings, the through flow coupler shown therein is provided between a prop 8 of a mine roof support and a hose 9. The coupler comprises two tubular parts 10 and 11, each having a through bore 13 therein ,. and a sleeve 12 which is captive with part 10 The parts 10 and 11 and the sleeve 12 are made of metal, e.g.. mild steel.

The part 10 has an externally threaded portion 14 for connection to an inlet/outlet port of the prop 8 and a frangible member 15 located in an annular groove 16.

The sleeve 12 is held captive with the part 10 by a crimped inwardly extending projection in the form of an annular flange 17 which engages behind the frangible member 15.

The frangible member 15 may be a split ring typically of metal alloy, such as copper alloy, brass or aluminium bronze, or of plastics material and is designed to shear when the fluid pressure within the coupler reaches a certain value. Alternatively, as shown in Figure 4, the frangible member 15 could be part annular, e.g. of generally horse shoe shape, and it could have a plurality of equi-angularly spaced, outwardly projecting lugs which co-operate with the crimped flange 17 and which shear away from the body of the frangible member when fluid pressure within the coupler reaches a certain value. Also, the ring 15 could be integral with the part 10, and in this case it could be in the form of an interrupted ring.

The part 11 is supplied fitted to the hose 9 and has an end portion 18 which fits inside the bore 13 at one end of the part 10, and a shoulder 19 which abuts against one end of part 10. The end portion 18, which is in the form of a plug, has an annular groove 20 locating elastomeric and plastics seals 20a and 20b, respectively, which establish a fluid tight connection between the two parts 10 and 11 when the two parts are held firmly together.

The sleeve 12 is fixed to the part 11 by a releasable connection comprising a U-shaped spring steel staple 21 whose arms 21a and 21b enter a pair of parallel tangential holes 22 within the sleeve 12 to engage in an annular groove 23 provided in the part 11.

The part 10 has at its one end an outwardly extending projection in the form of an annular flange 24. This flange 24 will be engaged by the flange 17 on the sleeve 12 to prevent total separation of the two parts 10 and 11 when the ring 15 shears and the parts move apart under the fluid pressure within the coupler.

This is important because if the parts 10 and 11 were to separate completely the hose 9 connected to the part 11 could flail about and injure an operative in the vicinity of the coupler.

A plurality of angularly spaced, radially extending apertures 25 are provided in the sleeve 12 intermediate its ends to disperse fluid which will escape between the parts 10 and 11 when the ring 15 shears.

The outer ends of apertures 25 are surrounded by a generally cylindrical shroud 26 which is located at one end in a shallow groove 27 formed in the sleeve 12.

Wring seals 28 and 29 provided between the sleeve 12 and the shroud 26 prevent the ingress of dirt to the apertures 25 during normal operation of the coupler, and in the event that the ring 15 shears, the O-ring seal 28 will blow out and fluid will be safely dispersed between the sleeve 12 and the shroud 26 towards the prop 8, as shown in Figure 2. Further seals 30 and 31 are provided between the part 10 and the sleeve 12.

The coupler described above has been purposely designed for use in mine roof supports and in particular to connect a hose 9 to the annulus of a prop 8 which is used to raise a roof engageable canopy relative to a floor engaging base section, and ideally the coupler is interchangeable with an existing coupler sp that it can be fitted to existing roof supports without difficulty.

However, the coupler described above has many other applications.

The frangible member could be replaced by some form of resilient means, e.g. Belville washers, or by a collapsible sleeve disposed between flanges 17 and 24, or by some form of releasable means, such as a circlip which will pop out of a locating groove when the fluid pressure exceeds a certain value.

Also, the crimped flange 17 could be replaced by a spring steel ring located in an annular groove in the inner surface of the sleeve 12. In this case, it may be necessary to interpose a metal washer between the spring steel ring and the frangible member 15, particularly if the latter is of plastics material, to prevent radial compression of one side of the fangible member caused by applying a sideways force to the hose.

In the example described above, this is prevented by contact between flange 17 and seal 30, and between sleeve 12 and the seal 31 in flange 24.

Various other modifications could be made to the coupler described above by persons skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims (18)

1. A through flow coupler comprising two parts having intercommunicating passage means so that fluid can flow through the two parts, sealing means for providing a fluid tight seal between the two parts when the two parts are held together, pressure sensitive means for holding the two parts together when in use the fluid pressure within said passage means is below a certain value and for allowing the two parts to move relative to one another so that fluid can escape from the passage means and relieve pressure therein when in use the fluid pressure within said passage means exceeds said certain value, and means preventing total separation of the two parts when the pressure sensitive means allows the two parts to move relative to one another.

2. A through flow coupler as claimed in claim 1, wherein said pressure sensitive means comprises frangible means breakable when the fluid pressure within said passage means exceeds said certain value.

3. A through flow coupler as claimed in claim 2, wherein the frangible means is in the form of an annular or part annular member fixed with respect to one of the two parts and engageable by a projection fixed with respect to the other part.

4. A through flow coupler as claimed in claim 1, wherein the pressure sensitive means is in the form resilient, collapsible or releasable means engageable by a projection fixed with respect to the other part.

5. A through flow coupler as claimed in claim 3 or claim 4, wherein the projection is in the form of an annular flange.

6 A through f1#w coupler as claimed in any one of claims 3 to 5, wherein the separation preventing means comprises the projection fixed with respect to the said other part and a further projection fixed with respect to said one part.

7. A through flow coupler as claimed in claim 6, wherein the further projection is in the form of an annular flange.

A Athrough flow coupler as claimed in any one of claims 3 to 7, wherein the first-mentioned projection is on a sleeve secured to the said other part by a releasable connection.

9. A through flow coupler as claimed in claim 8, wherein a plurality of apertures are provided in the sleeve to enable fluid escaping from the passage means to be dispersed.

10. A through flow coupler as claimed in claim 9, wherein the outer ends of the apertures are surrounded by a shroud.

11. A through flow coupler as claimed in any one of claims 8 to 10, wherein the releasable connection compises a U-shaped member whose arms enter a pair of parallel tangential holes in the sleeve to engage a groove in the said other part.

12. A through flow coupler as claimed in any one of the preceding claims, in the form of a hose coupling for use in an hydraulic or pneumatic line.

13. A through flow coupler as claimed in any one of the preceding claims, wherein the two parts are swivellable relative to one another.

14. A through flow coupler comprising a tubular part having a through passage therein, a sleeve mounted about, and projecting axially beyond, one end of the tubular part, means for connecting the part of the sleeve which projects beyond said one end of the tubular part to a further tubular part which is sealingly engageable with the first mentioned tubular part, pressure sensitive means for preventing relative axial slidable movement of the first mentioned tubular part and the sleeve when in use fluid pressure within the through passage is below a certain value and for allowing the sleeve to slide axially relative to the tubular part when in use the fluid pressure in the through passage exceeds said certain value, and means preventing total separation of the tubular part and the sleeve when the pressure sensitive means allows the sleeve to slide axially relative to the tubular part, the arrangement being such that when in use the sleeve is connected to said further tubular part, the further tubular part sealingly engages with the first mentioned tubular part unless the pressure sensitive means allows the sleeve and first mentioned tubular part to slide axially relative to one another when fluid can escape between the two tubular parts and relieve pressure within the two tubular parts.

15. A through flow coupler as claimed in claim 14, wherein the sleeve and first-mentioned tubular part are swivellable relative to one another.

16. A through flow coupler as claimed in claim 14 or claim 15, wherein said connecting means comprises a U-shaped member whose arms enter a pair of parallel tangential holes in the sleeve to in use engage a groove in the further tubular part.

17. A through flow coupler substantially as he-#inbefore described with reference to the accompanying drawings.

18. A mine roof support equipped with one or more through flow couplers as claimed in any one of the preceding claims.