GB2466036A

GB2466036A - Union nut with profiled aperture for installing over pipe end flange

Info

Publication number: GB2466036A
Application number: GB0822351A
Authority: GB
Inventors: Mark Coxon; Paul Leonard
Original assignee: GEORGE WILSON IND Ltd
Current assignee: GEORGE WILSON IND Ltd
Priority date: 2008-12-09
Filing date: 2008-12-09
Publication date: 2010-06-16
Also published as: GB0822351D0

Abstract

A profiled union nut 12 is used to secure a gas pressure regulator 22 to a union boss of a utility meter. The regulator 22 includes a liner 24 with a circumferential flange 26, and the nut 12 has a rim 18 with a non-circular shaped aperture. The aperture has a relatively larger portion allowing it to be slid over the liner flange 26, and a relatively smaller portion which is able to engage the flange which has been inserted and clamp it against the union boss. The nut 12 can be fitted from the flange end of the liner, and so is particularly suited for use with a one-piece regulator and liner (i.e. integrally cast) and with regulators having a liner already attached to the body of the regulator prior to fixing to the meter.

Description

A PROFILED NUT

The present invention relates to connecting gas pressure regulators and metering devices, and particularly relates to a profiled nut for securely connecting a regulator to a union boss of a type associated with a utility meter.

The use of gas pressure regulators (also known as "gas governers") is commonly known in the prior art and most, if not all, gas-consuming homes and premises will have a regulator installed in series with their gas utility meter. Typically, the regulator will be of a type usually referred to as a constant volume gas pressure regulator', which in use acts to control the pressure of the delivered gas.

is Conventional regulators normally comprise at least two components, a main regulator body having at least one gas conduit passing therethrough, and a liner', which is a relatively short tubular section of pipe that is adapted to connect to a union boss on a utility meter. By union boss' we mean a connector of standard size (i.e. within the domestic and commercial gas industry) that typically protrudes from a meter or metering device, and to which the regulator is secured by way of the liner. The liner generally includes a circumferential flange located at the end of the liner that connects to the boss. The function of the flange is to provide a laterally projecting lip (i.e. relative to the axis of the liner) to engage with a nut that acts to push down on the flange and to secure the liner to the boss.

The securing nut is usually fitted or hooped over' the liner prior to the liner being connected to the main body of the regulator. At the top end of the liner, that is the end opposite to that on which the flange is located, there is typically a helical screw thread, which engages with a reciprocal thread in the base of the regulator's main body. In this way, the regulator may then be secured to the meter simply by engaging the liner with the boss and screwing the nut onto the boss until it is tight. To ensure the integrity of the connection, an annular rubber washer (e.g. a BS746 standard flat washer) is usually included, which sits against the underlying surface of the flange and is held under compression when the nut is tightened.

However, although such regulators are commonly used in the domestic and commercial gas industry, there is a continuing need to reduce the cost associated with installing regulators on existing and newly provided meters. Therefore, it is desirable to supply engineers with regulators that already have the liners attached (i.e. screwed in place), and in some cases to manufacture the regulator and liner as a one-piece casting'. In the latter case, one-piece castings are particularly advantageous as they generally reduce manufacturing costs, as less machining is required due to the reduced number of parts, and improve the integrity of the connection, since the absence of a connection between the main body and liner eliminates the risk of leakage from this interface.

The use of pre-assembled regulators/liners (i.e. prior connected regulator bodies and liners) and one-piece castings is therefore highly desirable within the gas industry. However, the implementation of such components needs to be consistent with current meters and standardised connectors, so as to avoid a part or wholesale replacement of the existing gas delivery infrastructure. Therefore, there is a desire to make use of such components, while avoiding significantly changing existing fittings and fitting operations.

According to the present invention there is provided a profiled nut adapted to secure a regulator to a union boss, the regulator being of a type including a liner having a circumferential flange, the nut comprising: a body for engaging with a union boss on a meter, the body having an internal bore therethrough; a rim defining an aperture at one end of the bore, the aperture having an average size that is relatively smaller than the size of the bore, and in which the inner perimeter of the rim is profiled to permit a liner flange of a diameter relatively greater than the average size of the aperture to pass through the aperture to thereby secure the regulator to the boss.

It is to be understood that references herein to regulator' are intended to include all known gas pressure regulators and gas governers, whether for domestic or other use, and in particular, include both a two or multiple component regulator and liner, and a single unit regulator/liner (e.g. a one-piece casting).

The present invention seeks to address some or all of the above needs in the prior art by providing a profiled nut that can be used with any type of regulator having a liner with a circumferential flange and a standard union boss, without the need to change either component. Moreover, the profiled nut may be used with both pre-assembled regulators/liners and one-piece casting regulators and consequently may be readily implemented throughout the gas industry.

The profiled nut of the present invention comprises a body for engaging with a union boss of a type typically associated with a utility meter. In preferred embodiments, the utility meter is a domestic gas meter, but the nut may alternatively be used in conjunction with other meter types depending on the particular application. The body of the nut includes an internal bore that passes therethrough and is open at both ends. The diameter of the bore corresponds to the accepted industry standard size within the UK, which in turn corresponds approximately to the diameter of the union boss.

It is to be appreciated, however, that the industry standard size may differ from country to country. Therefore, the diameter of the bore may vary according to the approved industry standards within the territory of concern, without sacrificing any of the benefits of the present invention.

The internal surface of the bore is preferably threaded and takes the form of a helical thread reciprocal to that of the meter boss thread. In other embodiments, the internal surface may include an alternative locking mechanism, such as a bayonet-style' groove and detent etc. However, as most gas meters include a threaded boss, a helical thread is the most preferred arrangement.

The body of the nut is most preferably octagonal in cross-section, having eight smooth or flat faces around the outside of the nut. It is to be understood, however, that the body of the nut make take any suitable cross-sectional shape, including hexagonal, square and even circular. In the latter case, or more generally, any suitable texturised or grooved surface may be used to enhance grip for tightening/removing the nut.

The profiled nut further comprises a rim at the top of the nut, i.e. at the end opposite to the open end that engages with the threaded boss. The rim defines an aperture in the top of the nut that communicates with the internal bore. The average size of the aperture is relatively smaller than the size of the bore and therefore, as a result, the rim has a certain width around the circumference of the top of the nut.

In accordance with the invention, the inner perimeter of the rim is profiled to permit the circumferential flange of a liner to pass through the aperture, despite the diameter of the flange being greater than the average size of the aperture. In this way, the profiled nut can advantageously be fitted over the tubular body of the liner even if the liner is already attached to the body of the regulator or if the regulator/liner is a one-piece casting.

It is to be understood that references herein to average size' are to be taken to correspond to an aperture width derived from the mean of two of more diameters measured across the aperture from rim to rim, at any position around the perimeter of the rim.

Hence, the profiling of the rim allows pre-assem bled and one-piece casting regulators to be used in conjunction with existing union bosses without any need to modify the liner or boss. As a result, such regulators may then be implemented within the gas industry without changing any accepted industry standards. In this way, the profiled nut provides a cheap and simple solution to the problem of fitting one-piece regulators' to conventional meters, thereby allowing the industry to migrate to a widespread use of such components, while possibly lowering the associated manufacturing costs.

As one-piece castings only require one interface between the main body of the regulator and meter, the resulting connection is therefore significantly safer as the risk of any leakage between the regulator and liner is thereby avoided. Hence, the profiled nut of the invention facilitates the use of both pre-assembled and one-piece regulators, which in the latter case, may further improve the safety of the domestic meter installation.

The inner perimeter of the rim is preferably shaped such that the profile is non-symmetric along an axis parallel to the greatest width dimension of the aperture. By greatest width dimension' we mean the linear distance between the farthest, diametrically opposed, separated points on the perimeter of the aperture. An advantage of using a non-symmetric profile is that the rim width can be optirnised, so as to ensure a sufficient underlying surface remains (i.e. on the inside of the top of the nut) to exert a downward compression force on the liner flange when the nut is tightened on the boss thread. This optimisation is to ensure the integrity of the seal between the regulator and meter.

To further improve the integrity of the seal, and to ensure that the connection is suitably "leak-tight", an annular rubber washer is preferably disposed between the liner and union boss, which is held under compression by action of the tightened nut. A rubber washer may be used in conjunction with any of the embodiments of the present invention.

Preferably, the profile of the inner perimeter of the rim is defined by two adjacent sections, with one of the sections preferably having a greatest width dimension larger than the corresponding greatest width dimension of the other section. That is to say, one of the sections has a larger maximum linear separation between opposing points on the perimeter than the corresponding points for the other section. Again, as above, this feature serves to optimise the underlying rim surface available to compress the flange against the boss, i.e. the rim surface that engages the circumferential lip' of the flange.

Each adjacent section preferably defines a substantially arcuate portion of the inner perimeter of the rim, which thereby results in each section preferably prescribing a substantially semi-circular area that, in combination, defines the shape of the aperture. Due to the preferred asymmetry of the aperture, each section is consequently different in size to the other. The larger section is dimensioned so as to just permit the flange of the liner to be inserted into the aperture, when the profiled nut is angled relative to the longitudinal axis of the liner. Therefore, during fitting, the profiled rim permits the nut to be tilted relative to the liner axis to facilitate passage of the liner into and through the aperture. In this way, the nut may then be fitted over the tubular body of the liner ready for threading onto the boss of the meter.

When the liner is initially inserted into the aperture, the nut is preferably held at an angle of about 45-60 degrees to the axis of the liner. The circumferential flange passes through the larger section of the aperture and the nut is then preferably displaced laterally relative to the liner, or vice versa. In this way, the tubular body of the liner is then made to abut against the inner perimeter of the smaller section of the aperture, which is preferably dimensioned to have a greatest width slightly larger in size than the diameter of the body of the liner. The lateral displacement of the nut provides sufficient clearance for the body of the nut to be further tilted (to about 90 degrees relative to the liner axis), so that the remainder of the nut can be fitted over the flange, ready for use. It is to be noted that the forgoing angles are approximate and are measured with respect to the plane of the top of nut.

Thus, it is evident that by providing a larger section advantageously dimensioned for the diameter of the flange, and by providing the functionality to tilt the nut relative to the liner axis, the nut of the present invention can be fitted over a standard sized liner, even when the liner is already attached to the body of the regulator or when the liner is part of a one-piece casting. The above advantages may therefore be achieved without sacrificing any integrity of the resulting regulator and meter seal, while being simple and relatively cheap to implement.

The profiled nut of the present invention is preferably machined directly from steel or a suitable hard alloy. Alternatively, the nut may be cast using conventional techniques, or may be both cast and machined as required.

It is to be understood that any suitable profile may be used in conjunction with the nut of the invention, provided that there is a section which permits the liner to be inserted into and through the aperture, and which allows the nut to be tilted during fitting. That said, it is important to optimise the amount of underlying rim surface that remains available for compressing the flange of the liner, so as to ensure that the integrity of the seal is not compromised and remains fit-for-purpose'.

The present profiled nut may also be used in conjunction with liners that do not have a continuous circumferential flange, in that the flange may be comprised of two or more discrete arcuate ridges that extend in spaced relation around the body of the liner. However, such liners are not standard within the gas industry and therefore are not preferred for use with the present nut.

The present invention further provides a gas regulator that is configured to be attached to a utility meter. The regulator comprises a main body including at least one conduit, a liner connected to the body, the liner having a substantially circumferential flange and a profiled nut according to any of the preceding embodiments.

The present invention further provides a liner configured to be attached to a body of a regulator, the liner comprising a body in the form of a tubular conduit having a substantially circumferential flange, and a profiled nut according to any of the preceding embodiments.

Although the profiled nut of the present invention is ideally suited for use within the domestic and commercial gas industry, it is to be understood that one or more principles of the invention may have application in other similar or related industries, where it is necessary to securely connect pipes, tubes or other conduits that involve the use of pre-assembled components or one-piece castings etc. Embodiments of the invention will now be described in detail by way of example and with reference to the accompanying drawings in which: Figure 1 is a perspective view of an exemplary embodiment of a profiled nut according to the present invention.

Figure 2 is a perspective view of the profiled nut of Figure 1 shown in relation to a standard regulator of a type having a body and a liner.

Figures 3(a) & 3(b) show front and side plan views, respectively, of a preferred profiled nut being fitted to a standard regulator of a type having a body and a liner.

Figure 4 is a perspective view of a preferred profiled nut being fitted to a standard regulator of a type having a body and a liner.

Figure 5 is a perspective view of a preferred profiled nut shown fitted to a standard regulator of a type having a body and a liner.

Figure 6 is a perspective view of a standard regulator of a type having a body and a liner shown fitted to a utility meter by way of a profiled nut according to a preferred embodiment of the present invention.

Referring to Figure 1, there is shown a preferred embodiment of the profiled nut 10 according to the present invention. The nut 10 comprises a body 12 that is hexagonal in cross-section and is dimensioned according to the industry standard size for domestic gas meters. The nut 10 is machined using conventional techniques and is fabricated from hardened steel.

An internal bore 14 passes through the body of the nut and is open at both ends. The internal surface of the bore 14 is machined to provide one or more turnings of a helical thread 16, which corresponds to a reciprocal thread on the boss 28 of a standard gas meter 30 (depicted in Figure 6).

The nut 10 further comprises a circumferential rim 18 on the top of the body 12, i.e. at the end opposite to the open (threaded) end that engages with the boss 28 of the meter 30. The rim 18 defines an aperture 20 that communicates with the internal bore 14. The average size of the aperture is smaller than the size of the bore 14 and therefore, as a result, the rim 18 has a certain width around the circumference of the top of the nut 10.

As shown in Figure 1, the inner perimeter of the rim 18 (i.e. the inner edge of the rim) is profiled (shaped), so as to essentially define two adjacent sections, one relatively larger than the other. The profiling is achieved by machining the top of the nut 10, or alternatively, the nut may be cast directly with the profiled rim. Each adjacent section defines a substantially arcuate portion of the inner perimeter of the rim 18, which thereby results in each section prescribing an approximately semi-circular area that, in combination, defines the overall shape of the aperture 20.

Referring now to Figures 2 to 5, there is a shown a standard gas regulator of a type comprising a main body 22 and tubular liner 24. The body 22 and liner 24 may either be a pre-assembled' type (e.g. with the liner already screwed into the body of the regulator) or a one-piece casting. As clearly shown in Figure 2, the liner 24 is of a type that has a circumferential flange 26, which protrudes laterally at the lower end of the liner. The larger section of the aperture 20 is dimensioned so as to just permit the flange 26 of the liner 24 to be inserted into, and through, the aperture 20, despite the diameter of the flange being greater than the average size of the aperture.

In this way, the nut 10 can advantageously be fitted over the tubular body of the liner 24, even if the liner is already attached to the body 22 of the regulator or if the regulator/liner is a one-piece casting.

As shown in Figures 3(a) & 3(b), the nut 10 is fitted over the liner 24 by initially titling the nut 10 by an angle of between 45-60 degrees to the axis of the liner 24. The flange 26 is then inserted into the larger of the two sections of the aperture 20, by laterally sliding the liner 24, or nut 10 or both, until the tubular body of the liner is made to abut against the inner edge of the perimeter of the smaller section of the aperture, as shown in Figure 3(b) and more clearly in Figure 4. The smaller section of the aperture 20 is dimensioned to be slightly larger than the diameter of the body of the tubular liner 24, so that the liner can easily engage with the semi-circular perimeter of the smaller section. The lateral displacement of the liner 24 relative to the nut 10, provides sufficient clearance for the body of the nut to be further tilted (to about 90 degrees relative to the liner axis), permitting the reminder of the flange 26 to pass through the aperture 20, thereby allowing the nut 10 to be fitted over and onto the liner 24, as shown in Figure 5.

Hence, it is evident that the profiled nut 10 of the present invention can be fitted over standard size liners even if the liner is already attached to the body of the regulator or if the regulator/liner is a one-piece casting.

Moreover, as the advantages of the invention are achieved without any modification to the body of the regulator, liner or indeed the size of the nut, no changes are required within the gas industry in order to implement the invention.

Once the nut 10 has been fitted over the liner 24, the regulator may then be fitted to a boss 28 of a domestic gas meter 30, as shown in Figure 6.

An engineer can simply align the liner 24 with the boss 28 and thread the nut 10 onto the reciprocal thread of the boss 28. Tightening the nut 10 causes the underlying surface of the rim 18 (i.e. the surface on the underside of the top of the nut) to press down on the flange 26, sealing the liner 24 to the boss 28. To ensure an effective seal, an annular rubber washer may conventionally be used, which is held under compression when the nut is fully tightened.

An important feature of the invention is to optimise the width of the rim, so that the flange 26 is able to pass therethrough, but without compromising the eventual integrity of the seal. Therefore, the exemplary profile described above, and in relation to the accompanying figures, has been found to be the optimum shape for the profile of the nut, as it allows the use of pre-assembled and one-piece regulators/liners to be implemented practically, while still achieving a reliable and safe connection between the regulator and meter.

Of course, other profiles may alternatively be used that still establish an effective and secure seal, and consequently such shapes are taken to be consistent with any of the embodiments of the present invention.

The above embodiments are described by way of example only. Many variations are possible without departing from the invention.

Claims

CLAIMS1. A profiled nut adapted to secure a regulator to a union boss, the regulator being of a type including a liner having a circumferential flange, the nut comprising: a body for engaging with a union boss on a meter, the body having an internal bore therethrough; a rim defining an aperture at one end of the bore, the aperture having an average size that is relatively smaller than the size of the bore, and in which the inner perimeter of the rim is profiled to permit a liner flange of a diameter relatively greater than the average size of the aperture to pass through the aperture to thereby secure the regulator to the boss.
2. The nut as claimed in Claim 1, wherein the profile of the inner perimeter is non-symmetric along an axis parallel to the greatest width dimension of the aperture.
3. The nut as claimed in Claim 1 or Claim 2, wherein the profile of the inner perimeter is defined by two adjacent sections.
4. The nut as claimed in Claim 3, wherein one section has a greatest width dimension larger than the corresponding greatest width dimension of the other section.
5. The nut as claimed in Claim 3 or Claim 4, wherein each section defines a substantially arcuate portion of the inner perimeter.
6. The nut as claimed in any of Claims 3 to 5, wherein each section prescribes a substantially semi-circular area, different in size to the other, that in combination defines the shape of the aperture.
7. The nut as claimed in any preceding claim, wherein the profiled rim is configured to permit the nut to be tilted relative to the liner to facilitate passage of the liner through the aperture.
8. The nut as claimed in any preceding claim, wherein the underlying surface of the rim acts as a surface for engaging the circumferential lip of the flange.
9. The nut as claimed in any preceding claim, wherein the internal bore is threaded.
10. The nut as claimed in any preceding claim, wherein the body is octagonal in cross-section.
11. A regulator configured to be attached to a union boss of a type associated with a utility meter, comprising: a main body including at least one conduit; a liner connected to the body, the liner having a substantially circumferential flange; and a profiled nut according to any of the Claims 1 to 10.
12. A liner configured to be attached to a body of a utility meter regulator, comprising: a tubular conduit having a substantially circumferential flange; and a profiled nut according to any of the Claims 1 to 10.
13. A profiled nut as substantially described herein with reference to the accompanying drawings.