AU2019100400B4

AU2019100400B4 - Plumbing Fitting

Info

Publication number: AU2019100400B4
Application number: AU2019100400A
Authority: AU
Inventors: Aleksy Ziarkowski; Simon Ziarkowski
Original assignee: Mainset Pty Ltd
Current assignee: Mainset Pty Ltd
Priority date: 2018-12-19
Filing date: 2019-04-12
Publication date: 2019-11-21
Anticipated expiration: 2027-04-12
Also published as: AU2019100400A4; AU2019100400C4

Abstract

Abstract An O-ring-free plumbing fitting (10) comprising a hollow body (14) and a tubular engagement portion (12) opening to the hollow body (14) for engagement within a pipe. The tubular engagement portion (12) comprises a tapered distal end (16) for receiving the pipe and an arrangement of circumferential ribs (22) each of the same diameter between the tapered distal end portion (16) and a proximal end portion (18) of the tubular engagement portion (12). The arrangement of circumferential ribs (22) sealingly engages the pipe when the pipe is crimped on the tubular engagement portion (12) with a sleeve retaining member (6) and an overlying crimping sleeve (120). The arrangement includes at least one elongated flat circumferential rib (24) and at least one barbed circumferential rib (20, 26) on each side of each elongated flat rib. Each elongated flat rib (24) has a flat outer sealing surface with a length of at least 1.5 mm.

Description

PLUMBING FITTING

Field of the Invention

The present invention relates to a plumbing fitting for receiving the end portion of a length of pipe and is particularly concerned with such a plumbing fitting to which the pipe end portion can be sealingly secured without the use of an O-ring seal to provide a seal between the pipe end portion and the plumbing fitting. The invention also extends to an assembly of such a plumbing fitting and an overlying securing element, with or without a pipe end portion received between the plumbing fitting and the overlying securing element.

Throughout this specification, unless the context requires otherwise, the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Background Art

The following discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge as at the priority date of the application.

Plumbing fittings for connecting to the end portion of a fluid transfer pipe, such as for water or gas, are well known. They include end stop fittings, elbow fittings, straight fittings and T-fittings. One pipe portion will be engaged with an end stop fitting, and usually two with elbow and straight fittings and three with a T-fitting. However, some elbow, straight and T-fittings may have a threaded opening. The invention is not concerned with threaded openings on plumbing fittings. Commonly the plumbing pipes are formed of plastics material such as polyethylene, for example PEX, or layered composites with polyethylene. With such composite pipes a layer of aluminium may be sandwiched between two layers of plastics material such as PEX. Composite pipes are

28782 often used for conveying gas.

A variety of different methods is known for sealingly securing the end portion of a length of pipe to a nozzle or tubular engagement portion of the pipe fitting, including push fittings, expansion fittings, compression fittings and crimp fittings.

The present invention is particularly concerned with crimp fittings, which are sometimes alternatively known as press sleeve fittings. In either case a plastically deformable ring or sleeve, such as of copper, copper alloy or stainless steel, is pressed or crimped over the pipe end portion on the tubular engagement portion of the plumbing fitting to sealingly secure the pipe end portion on the plumbing fitting. Throughout this specification the term “crimp” will be used to encompass both crimp fittings and press sleeve fittings. Furthermore, the term “sleeve” will be used throughout and it is to be understood that the term encompasses crimping rings and sleeves of any suitable length.

Some examples of plumbing fittings that use crimping sleeves to secure a pipe end portion to a tubular engagement portion of the fitting are described in patent specifications WO2018112529, US2007007761, US5228721, EP1790896 and AU2012200536.

WO2018112529 is primarily directed to a specific type of crimping jaw for crimping a particular type of sleeve on to the pipe end portion received on the fitting tubular engagement portion. A straight fitting is illustrated in the specification and the plumbing fitting has a series of short circumferential ribs along the tubular engagement portion between which the material of the crimped pipe is squeezed to provide the secure seal between the pipe and the fitting. Excess material of the crimping sleeve is accommodated as a rib in a longitudinal groove of the jaw.

US2007007761 is directed to a plumbing fitting in which each tubular engagement portion is provided with a series of short flat circumferential ribs with an O-ring of the same diameter provided between two such ribs to provide the secure seal between the pipe and the fitting after crimping. Crimped material of the pipe is received in respective

28782 grooves on the opposite sides of the ribs. Straight and T- fittings are illustrated in the specification.

US5228721 is directed to a crimp sleeve plumbing fitting in which a resilient sleeve is provided between the pipe end portion received on the tubular engagement portion of the plumbing fitting and the crimping sleeve. The tubular engagement portion has a pair of spaced-apart rounded circumferential ribs to provide a seal between the pipe end portion and the tubular engagement portion. In one embodiment, the tubular end portion additionally has a pair of spaced-apart barbed circumferential ribs distally of the rounded ribs to additionally resist removal of the pipe end portion.

EP1790896 is also directed to a crimped sleeve plumbing fitting having a series of circumferential sealing ribs, disposed distally of an annular groove for receiving crimped material of the pipe end portion, that are all barbed.

AU2012200536 is primarily directed to a crimping sleeve for a plumbing fitting but the tubular engagement portion of the fitting has a combination of circumferential barbed ribs and O-ring seals disposed in annular grooves between the ribs. Additionally, one of the faces of each annular groove receiving an O-ring seal is defined by a short flat circumferential rib between the groove and the adjacent barbed rib. The O-ring seals stand proud of the flat and barbed ribs and in use provide at least the majority of the sealing with the pipe end portion, while the barbed ribs resist removal of the pipe from the fitting.

Currently, crimped plumbing connections including one or more O-ring seals provide the most secure connection from the perspective of long-term resistance to leakage and therefore generally should be preferred by the plumbing industry. However, this is not the case.

AS/NZS 3500.1.2018 requires that every crimped plumbing connection must be pressure tested for leakage once the pipe end portion has been crimped to the plumbing fitting. Such pressure testing is designed to identify not only a poorly crimped connection but also a plumbing connection for which the crimping has been overlooked.

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In a typical new residential or commercial building there may be a very large number of water and/or gas plumbing connections and the risk of one inadvertently remaining uncrimped is relatively high.

A disadvantage of plumbing connections using O-ring seals is that when they are pressure-tested they may not fail during the test even if they have not been crimped. Thus, the seal provided by the O-ring seal(s) is so good that it may not leak immediately even when the connection has not been crimped. However, such an uncrimped connection has been found to ultimately fail, perhaps even several months later, sometimes with disastrous results - especially if the connection is difficult to access once the building or plumbing work has been completed.

It would be very desirable to provide an improved plumbing fitting that can provide a good seal after crimping over a connected pipe end portion but that will leak under pressure if the connection is not crimped.

Summary of the invention

According to a first aspect, there is provided herein an O-ring-free plumbing fitting comprising: a body; a tubular engagement portion opening to the body for engaging with a pipe, the tubular engagement portion comprising: a distal end for receiving the pipe; and, an arrangement of circumferential ribs extending substantially around a circumference ofthe tubular engagement portion, the circumferential ribs being disposed between the distal end and a proximal end portion of the tubular engagement portion, the arrangement of circumferential ribs comprising at least one elongated flat circumferential rib and at least one barbed circumferential rib on each side of each elongated flat rib; and a crimping sleeve for overlying on the tubular engagement portion; wherein the arrangement of circumferential ribs are configured to sealingly engage the pipe when the pipe is crimped on the tubular engagement portion and the crimping sleeve.

According to the present invention, there is provided an O-ring-free plumbing fitting comprising a hollow body and a tubular engagement portion opening to the hollow body

28782 for engagement within a pipe, the tubular engagement portion comprising a tapered distal end for receiving the pipe and an arrangement of circumferential ribs each of the same diameter between the tapered distal end portion and a proximal end portion of the tubular engagement portion, the arrangement of circumferential ribs being adapted to sealingly engage the pipe when the pipe is crimped on the tubular engagement portion with an overlying crimping sleeve and comprising at least one elongated flat circumferential rib and at least one barbed circumferential rib on each side of each elongated flat rib.

Preferably, each such elongated flat rib has a flat outer sealing surface with a length of at least 1.5 mm.

Further according to the present invention there is provided a kit of a plumbing fitting as described in the immediately preceding paragraph and a crimping sleeve. The kit may be an assembly of the plumbing fitting and the crimping sleeve, with an uncrimped crimping sleeve optionally being held in place by a suitable retaining member.

By the term Ό-ring-free” is meant that the any tubular engagement portion of the plumbing fitting that is in accordance with the invention has no O-ring and is capable of sealing a crimped pipe end portion thereon without an O-ring seal. The plumbing fitting may have one or more other tubular engagement portions that are not in accordance with the invention, that is they do not have the series of barbed and elongated flat circumferential ribs as defined, and/or some other component that does include an Oring seal.

By the present invention it is found that the combination of flat and barbed circumferential flanges can provide an excellent long-term seal with the pipe end portion after crimping while resisting removal of the pipe from the tubular engagement portion of the fitting, with the crimped material of the pipe end portion being received in annular grooves between the circumferential ribs. The circumferential ribs are all of the same diameter, preferably about the same diameter as the internal diameter of the pipe end portion, and also provide some resistance to removal of the pipe end portion prior to crimping. The circumferential ribs do not provide substantial resistance to leakage prior

28782 to crimping, so an uncrimped connection will be highlighted by pressure testing.

It has been found that the minimum length of 1.5 mm of the flat outer sealing surface of each elongated flat rib provides a satisfactory seal after crimping. A length in excess of, for example, 2.5 mm is considered unnecessary, especially if there is more than one elongated flat rib. A preferred minimum length of the flat outer sealing surface of each elongated flat rib is 1.75 mm, and most preferably the length is about 2 mm, for example 1.9 mm to 2.1 mm.

In one embodiment, the arrangement of circumferential ribs of the same diameter between the proximal and distal end portions of the tubular engagement portion comprises two of the elongated flat ribs. This is preferred with a tubular engagement portion of 20 mm to 30 mm in length. Such length of tubular engagement portion provides advantageous stability to the pipe end portion on the engagement portion prior to crimping.

The or each circumferential elongated flat rib has one or more circumferential barbed ribs to each side thereof. In one embodiment, two barbed ribs are provided between the tapered distal end and the adjacent elongated flat rib. In an embodiment where two elongated flat ribs are provided there may be, for example, two or three circumferential barbed ribs between them. For the same number of elongated flat ribs, the number of barbed ribs provided between them may increase for longer tubular engagement portions.

The circumferential barbed ribs have inclined outer faces that taper outwardly away from the tapered distal end portion to resist withdrawal of the pipe end portion from the tubular engagement portion. The tapered distal end portion may merge in to a circumferential barbed rib. To minimise damage from the peak of each barbed rib excessively digging in to the crimped pipe end portion, the peak may be flattened to extend parallel to and at the same height as each elongate flat rib. The length of the flattened peak may be, for example, from 0.2 mm to 0.5 mm. In one embodiment it is about 0.3 mm.

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The length of each barbed rib will usually be in the range of 1.5 mm to 5 mm, preferably 2 mm to 4 mm. As a general rule, larger diameter tubular engagement portions may have relatively longer barbed ribs.

The height of each circumferential rib between the tapered distal end portion and the proximal end portion ofthe tubular engagement portion may be in the range of, for example, 0.3 mm and 1 mm, preferably 0.4 mm to 0.7 mm. In one embodiment, the height (or depth of the annular groove between the ribs) is about 0.5 mm. The height should not be so great that the circumferential ribs in particular dig excessively in to the material of the crimped pipe end portion but should be sufficient to effectively secure the crimped pipe end portion on to the tubular engagement portion.

The proximal face of each barbed rib, that is the face closest to the proximal end portion of the tubular engagement portion, may extend outwardly at any suitable angle, preferably at an angle that is no more than 10o from a radial plane ofthe tubular engagement portion. In one embodiment, the proximal face extends in a radial plane.

Opposed side walls of the or each circumferential elongated flat rib may extend at any suitable angle. Preferably however, each side wall extends in a respective plane that is at least substantially radial (within 10° of radial). An annular groove is formed between each circumferential elongated flat rib and the distally adjacent barbed rib. Where each of the respective side wall of the elongated flat rib and the proximal face of the adjacent barbed rib extends in a radial plane, the annular groove will have parallel radial walls. The bottom of the annular groove may be any desired shape, but in one embodiment extends parallel to the axis ofthe tubular engagement portion. The depth of this annular groove may be as described above for the depth of other annular grooves between the ribs of the arrangement of circumferential ribs. The length of this annular groove should be sufficient to accommodate crimped material ofthe pipe end portion but usually less than the length ofthe adjacent circumferential elongate flat rib, for example in the range 1 mm to 2 mm, preferably 1 mm to 1.5 mm. In one embodiment the length is about 1.2 mm.

An elongated land of the same diameter as the arrangement of circumferential ribs may

28782 be provided closest to the proximal end portion of the tubular engagement portion to advantageously provide location stability to the pipe end portion when the pipe end portion is fully received on the tubular engagement portion but not yet crimped. The land, which does not have a barbed rib ofthe same diameter proximal of it, may have the same or a greater length than the circumferential elongated flat rib(s), for example in the range 1.5 mm to 5 mm. In one embodiment the length may be in the range 3 mm to 4 mm.

The proximal end of the tubular engagement portion may comprise a shoulder that directly or indirectly limits the sliding movement ofthe pipe end portion on to the tubular engagement portion. Thus, the shoulder may be integrally formed as part of the plumbing fitting and receive the end face of the pipe end portion abutted against it. Alternatively, it may act as a stop for a distinct component that separates the end face ofthe pipe end portion from the material ofthe plumbing fitting. This can be advantageous where the pipe material incorporates a metal component which it is desired to isolate from a metallic plumbing fitting and the distinct component is not metallic. The metal component of the pipe may be an aluminium or other metal or metallic layer of a composite pipe such as may be used for conveying gas. The distinct component will itself have a face against which the end face ofthe pipe end portion can abut.

The distinct component is conveniently formed from a plastics material such as polyethylene, but any suitable material may be adopted. Advantageously, the distinct component acts as a retainer for the crimping sleeve both during transport and storage of the plumbing fitting and sleeve and prior to crimping of the sleeve over the pipe end portion by releasably holding one end of the sleeve. The releasable hold may be any suitable arrangement, including friction fit, screw thread and cooperating lug fittings, but the preferred arrangement is by snap engagement of a resilient material ofthe component over an enlarged or flared end portion ofthe sleeve. In this arrangement the distinct component will have an annular internal flange or annular series of internal flanges to ride over the sleeve enlarged end portion and resiliently snap behind it.

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The distinct component may be held on the proximal end of the tubular engagement portion by any suitable arrangement, including friction fit, cooperating screw thread and cooperating lug fittings, but the preferred arrangement is by snap engagement of a resilient material of the component over a securing annular rib or annular series of rib portions on the proximal end of the tubular engagement portion.

The securing rib or rib portions may be disposed between the aforementioned proximal circumferential elongated flat rib and the aforementioned shoulder where these are provided, with an annular grove between the securing rib or rib portions and the shoulder to receive the distinct component.

The plumbing fitting may be formed of any suitable material, including metallic and plastics. A common metallic material for such fittings is brass, but other suitable metals or metallic materials include copper, galvanized iron and stainless steel. Common plastics material for such fittings are ABS, PVC and CPVC. Both metallic and plastics plumbing fittings may be formed by casting or moulding, optionally with additional machining.

Where the plumbing fitting has more than one tubular engagement portion for receiving respective pipe end portions, each or only one or some need be in accordance with the invention. Any that is not in accordance with the invention may take any known form, such as mentioned above or, for example, a screw thread to receive a correspondingly screw-threaded fitting secured to the end of a pipe end portion or other component.

The crimping sleeve used with the present invention may be of any suitable material, including copper, copper alloy and stainless steel, preferably stainless steel. A most preferred stainless steel is 304, but other grades may be used.

Advantageously the crimping sleeve has at least one sighting opening or cutout to visually confirm the correct position of the sleeve relative to the pipe end portion. The sighting opening or cut-out may also have the advantage of facilitating leakage from the sleeve during testing of an inadvertently uncrimped sleeve.

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Crimping may be performed using a crimping tool that presses at least substantially the entire length ofthe crimping sleeve but applies additional localised circumferential pressure points. Examples of such a tool are illustrated in the aforementioned

EP1790896 and WO2018112529. Where this is the case, the localised circumferential pressure points are advantageously offset from the circumferential elongated flat rib or ribs and over the region of the barbed rib or ribs to each side of the or each circumferential elongated flat rib that has barbed ribs on both sides.

Brief Description ofthe Drawings

The invention will be better understood in light of the following description of the best mode for carrying out the invention. The description is made with reference to the following drawings that consist of various views according to different embodiments of the present invention.

FIG 1 is a part sectional view of a plumbing elbow fitting incorporating an embodiment of the invention;

FIG 2 is a part sectional view of a plumbing T-fitting incorporating an embodiment of the invention;

FIG 3 is a part sectional view of an alternative plumbing elbow fitting incorporating an embodiment of the invention;

FIG 4 is an exploded perspective view of a further alternative plumbing elbow fitting incorporating an embodiment ofthe invention together with a sleeve retaining member and crimping sleeve;

FIG 5 is an exploded perspective view similar to Fig 4 but showing a plumbing straight fitting incorporating an embodiment ofthe invention; and

FIG 6 is a sectional view of a tubular engagement portion of a plumbing fitting incorporating an embodiment ofthe invention with a composite pipe end portion crimped on to the engagement portion.

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Best Mode(s) for Carrying Out the Invention

The best mode for carrying out the invention includes an O-ring-free plumbing fitting having a tubular engagement portion for receiving a pipe end portion, the tubular engagement portion comprising an arrangement of circumferential ribs each of the same diameter adapted to sealingly engage the pipe end portion when the pipe end portion is crimped on the tubular engagement portion, the arrangement of circumferential ribs comprising at least one elongated flat circumferential rib and at least one barbed circumferential rib to each side of each elongated flat rib.

In the embodiments of Figs 1 to 5, the same arrangement of circumferential ribs is illustrated, with two spaced elongated flat circumferential ribs each having two circumferential barbed ribs to each side. However, it will be appreciated that the arrangement may differ, with more or fewer elongated flat circumferential ribs and more or fewer circumferential barbed ribs to each side of each elongated flat circumferential rib. There is no requirement for the same number of circumferential barbed ribs to be provided to each side of each elongated flat circumferential rib. The choice of numbers of each type of ribs may be determined by trial and error in order to give the desired Oring-free seal and the desired retention of the pipe end portion on the tubular engagement portion after crimping. By way of example, the tubular engagement portion in the embodiment of Fig 6 is similar to that in Figs 1 to 5 but differs by having three circumferential barbed ribs between the two elongated flat circumferential ribs.

It has been found that the arrangement of two barbed circumferential ribs to each side of two elongated flat circumferential ribs of about 2 mm length to give good sealing and pipe security for most plumbing fittings, but a greater number of barbed circumferential ribs may be advantageous for larger diameter pipes.

In the following description of the drawings, for convenience only the same reference numerals will be used for the same features in different embodiments. In some instances a prime.....will be used to denote a variation of a feature.

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Referring to Fig. 1, a brass elbow plumbing fitting 10 is shown with two identical tubular engagement portions 12 extending from a hollow body 14 and in communication with each other through the hollow body. For convenience, only one of the tubular engagement portions 12 will be described in detail.

Each tubular engagement portion 12 has a tapered distal end wall 16 to facilitate engagement with the pipe end portion (not shown) as it is slid on to the tubular engagement portion and a proximal end portion 18 extending from the hollow body 14 to an enlarged circumferential barbed rib 20. An arrangement 22 of circumferential ribs of identical diameter is provided between the tapered distal end wall 16 and the enlarged barbed rib 22 of the proximal end portion 20.

The arrangement 22 of ribs comprises two elongated flat circumferential ribs 24 each with two barbed circumferential ribs 26 to each side. Each elongated flat circumferential rib 24 has a flat outer sealing surface 28 having a length of about 2 mm that extends parallel to the axis 30 of the tubular engagement portion and opposed walls 32 and 34 that extend in respective radial planes.

Each barbed circumferential rib 26 has an inclined outer surface 36 (relative to the axis 30) that tapers outwardly towards the proximal end portion 18 and a proximal end face 38 that extends in a respective radial plane. The inclined outer surface 36 of the distalmost barbed rib 26a effectively forms the tapered distal end 16 of the tubular engagement portion 12. The circumferential apex 40 of each barbed rib 26 is flattened so as to extend parallel to the axis 30 in order to ensure it is not so sharp that it cuts excessively in to the material of the crimped pipe end portion. In the embodiment shown, each barbed rib 26 has an axial length of about 2 mm and the flattened apex 40 has a length of about 0.3 mm.

Between the circumferential ribs 24 and 26 of the array 22 is a series of annular grooves 42 and 44 in to which the material of the pipe end portion is crimped to ensure the pipe end portion is securely held on the tubular engagement portion 12. The annular grooves 42 are defined by the inclined outer surface 36 of each barbed rib 26 and either the proximal end face 38 of an adjacent barbed rib 26 or the proximal end

28782 face 32 of a distally adjacent elongated flat circumferential rib 24. Their depth is therefore defined by the radial extent ofthe respective proximal end face 38 or 32. In the embodiment shown it is about 0.5 mm and the diameter of the tubular engagement portion is about 11.7 mm. However, a greater groove depth may be provided for larger diameter tubular engagement portions.

Each annular groove 44 is disposed between the distal end face 34 of each elongated flat circumferential rib 24 and the proximal end face 38 ofthe distally adjacent barbed rib 26 and has a circumferential bottom face 46 that extends parallel to the axis 30. The grooves 44 conveniently have the same depth as the grooves 42 and an axial length of about 1.2 mm.

Between the proximal barbed circumferential rib 26b and the proximal end portion 18 of the tubular engagement portion 12 is a merge portion 48 comprising an annular land 50 and a tapered annular surface 52. The annular land 50 extends distally from the enlarged barbed circumferential rib 20 and is ofthe same diameter as the array 22 of circumferential ribs to provide a proximal support surface for the pipe end portion. In the embodiment shown the land 50 has an axial length of about 3 mm.

The tapered annular surface extends from the land 50 to the radially inner edge ofthe proximal end face 38 ofthe barbed circumferential rib 26b and conveniently has a similar axial length to the outer surfaces 36 ofthe barbed circumferential ribs 26.

The proximal end portion 18 of the tubular engagement portion 12 comprises the enlarged barbed circumferential rib 20 and an annular flange 54 proximally spaced from the circumferential rib 20 by an annular groove 56. The flange 54 forms a shoulder having a distal end face 58 that extends radially and acts as a stop for a sleeve retaining member 60 (shown in Figs 4 to 6). The sleeve retaining member is formed of an elastomeric material and is resiliently forced proximally over the enlarged barbed rib 20 before snapping back in to the groove 56 where it is held securely in abutment with the end face 58 of the flange 54. To alleviate cutting damage to the elastomeric material of the sleeve retaining member 60, the enlarged barbed rib 20 has a flattened

28782 apex 62 similar to the flattened apices 40 of the barbed ribs 26.

Although the two tubular engagement portions 12 of the fitting 10 are identical, this is not essential. One of the tubular engagement portions could differ but still be in accordance with the invention, for example with different numbers and/or proportions of the circumferential ribs 24 and 26 or a modified proximal end portion 18. Alternatively, one of the tubular engagement portions may not be in accordance with the invention. One such embodiment is shown in Fig. 3.

Turning to Fig. 2, a brass T-fitting 70 has three identical tubular engagement portions 12, extending from and communicating with a hollow body 72, for receiving respective pipe end portions (not shown). As the tubular engagement portions are each identical to the tubular engagement portions 12 in Fig. 1 they will not be described further. However, it will be appreciated that the comments in the immediately preceding paragraph regarding the two tubular engagement portions ofthe fitting 10 apply equally to the three tubular engagement portions of the plumbing fitting 70.

Fig. 3 illustrates a different brass elbow fitting 80 comprising a single tubular engagement portion 12 extending from a hollow body 82 and a second tubular engagement portion 84 not in accordance with the invention extending perpendicularly to the tubular engagement portion 12. Again, as the tubular engagement portion 12 is identical to the tubular engagement portions 12 of Figs. 1 and 2 it will not be described further.

The second tubular engagement portion 84 is elongated and hollow and has an external screw thread 86 along its entire length for receiving a cooperating screwthreaded fitting, such as a valve (not shown), thereon. The screw thread 86 is illustrated schematically in the figure.

The hollow body 82 is adapted for mounting on a surface by having a base 88 with a planar bottom surface 90 and an opening 92 therethrough for receiving a fastener (not shown).

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Figs. 4 and 5 show two brass plumbing fittings 100 and 110, respectively. The plumbing fitting 100 is another embodiment of an elbow fitting with a hollow body 102, while the plumbing fitting 110 is a straight fitting with a hollow body 112 having an external hexagonal nut profile 114. Each of the fittings 100 and 110 has a single tubular engagement portion 12 extending from and communicating with the respective hollow body 102 or 112. The single tubular engagement portions 12 of the fittings 100 and 112 are identical to the previously described tubular engagement portions 12 and, for convenience only, will not be described further.

A second tubular engagement portion 104 of the elbow fitting 100 in Fig. 4 is open to the hollow body 102 and is diametrically enlarged relative to the tubular engagement portion 12 of the fitting and has an external screw thread 106 for receiving a correspondingly screw-threaded fitting (not shown), for example on a second pipe end portion.

A second tubular engagement portion 116 of the elbow fitting 110 in Fig. 5 is open to the hollow body 112 and is diametrically enlarged relative to the tubular engagement portion 12 of the fitting and has an external screw thread 118 for receiving a correspondingly screw-threaded fitting (not shown), for example on a second pipe end portion.

Each of Figs. 4 and 5 is an exploded view showing not only the respective plumbing fitting 100 and 110 but also the polyethylene sleeve retaining member 60 and a crimping sleeve 120. The sleeve retaining member 60 and crimping sleeve 120 are identical in the two embodiments and the following description will apply to both embodiments. For additional clarity, reference may also be had to Fig. 6 showing a sectional view inter alia of the sleeve retaining member 60 and of the crimping sleeve 120 (in a crimped condition) on a modified tubular engagement portion 12’.

The injection moulded annular sleeve retaining member 60 is designed to securely, but releasably, hold the crimping sleeve 120 on the tubular engagement portion 12, 12’ of the plumbing fitting prior to crimping, for example during transport and storage. It also prevents any metallic layer of the pipe end portion 122 received on the tubular

28782 engagement portion 12, 12’ from coming in to contact with the metallic body of the plumbing fitting, as described below with reference to Fig. 6.

The sleeve retaining member 60 has an annular radially extensive main body 124 with opposite axially-directed radially inner and radially outer annular flanges 126 and 128. The proximally-directed inner flange 126 has a proximal inwardly-directed annular lip 130 that is sized and shaped to be accommodated in the groove 56 of the proximal end portion 18 of the tubular engagement portion 12, 12’, as clearly shown in Fig. 6. In order to secure the sleeve retaining member 60 in the groove 56 the sleeve retaining member is displaced axially over the tubular engagement portion until it abuts the enlarged barbed rib 20 of the proximal end portion 18. Further axial displacement will cause the elastomeric member 60 to resiliently expand over the rib 20 until it is able to snap back in to the annular groove 56.

The distally-directed outer flange 128 of the sleeve retaining member 60 has a distal inwardly-directed annular lip 132 that defines with the main body 124 an inwardly facing annular groove 134 (see Fig. 6) for receiving an outwardly flared end 136 of the crimping sleeve 120. The flared end 136 is received in the groove 134 by the lip 132 and flange 128 resiliently flexing as the flared end is displaced axially past the lip and then snapping back to their original shape once the flared end enters the groove. To facilitate the proximal displacement of the flared end 136 past the lip 132, a distal end face 138 (see Fig. 6) of the lip is inclined inwardly in the proximal direction.

The crimping sleeve 120 has an annular body 140 that is formed of 314 stainless steel and in the embodiment shown is sized to be closely received over the pipe end portion 122 prior to crimping. However, other arrangements are possible such as are described in the aforementioned patent specifications. The flared end 136 is at the proximal end of the annular body 140, and a correspondingly flare 142 is provided at the distal end.

The distal outwardly flared end 142 may assist, with proximal flared end 136, location of crimping jaws (not shown) during crimping but is not otherwise necessary.

The annular body 140 has a plurality of openings 144 therethrough adjacent the proximal flared end 136 to allow sighting of the correct location of the pipe end portion

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122 inside the uncrimped sleeve 120. The openings 144 may also facilitate passage of water from the pipe end portion during a pressure leakage test should the sleeve 120 have been left uncrimped inadvertently, and thereby more readily show the failure of the test.

Fig. 6 shows a modified tubular engagement portion 12’, having a larger diameter than the tubular engagement portion 12 in Figs. 1 to 5 and three barbed ribs 26 between the two elongated flat ribs 24. The three barbed ribs 26 intermediate the flat ribs 24 help to better hold the larger pipe end portion 122 (relative to a pipe end portion secured on the tubular engagement portions 12 of Figs. 1 to 5), and all of the ribs 24 and 26 of the tubular engagement portion 12’ may have a slightly deeper profile for the same reason. In all other respects the tubular engagement portion 12’ is the same as the tubular engagement portions 12, and for convenience it will therefore not be described further.

Figure 6 shows the sleeve retention member 60 located in the annular groove 56 ofthe proximal end portion 18 and the sleeve 120 crimped over the pipe end portion 122. The flared proximal end ofthe sleeve 120 is disposed in the annular groove 134 ofthe sleeve retention member 60, and the end face ofthe pipe end portion 122 abuts the body 124 ofthe sleeve retention member.

In the embodiment of Fig. 6 the pipe, as reflected by the pipe end portion 122, is multilayered with a thin layer of aluminium 146 sandwiched between inner and outer layers 148 and 150 of PEX. Such a fluid transfer pipe construction is known, particularly for transfer of natural gas and other domestic gases such as LPG and will not be described further. The same pipe construction could be used for pipes for transferring hot and cold water but is generally not necessary, and more usually such a pipe would be formed of a PEX monolayer.

The pipe end portion 122 and sleeve 60 have been crimped using a jaw (not shown) which applies circumferential pressure along the length ofthe sleeve but also three circumferential pressure points 152 at the axial locations shown by lines 154. Each of these pressure points is axially offset from the elongated flat circumferential ribs 24 so as to ensure the material of the pipe end portion 122 is forced in to the annular

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2019100400 23 Oct 2019 grooves 42 and 44 of the tubular engagement portion 12’.

While various embodiments of the invention have been described, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit or the scope of the invention. Accordingly, it is intended to claim all such changes and modifications as falling within the scope of the invention.

It is apparent from the above, that the arrangements described are applicable to residential and commercial plumbing and other related industries.

Claims

The Claims Defining the Invention are as Follows:

1. An O-ring-free plumbing fitting comprising:

a. a body;

b. a tubular engagement portion opening to the body for engaging with a pipe, the tubular engagement portion comprising:

i. a distal end for receiving the pipe; and, ii. an arrangement of circumferential ribs extending substantially around a circumference of the tubular engagement portion, the circumferential ribs being disposed between the distal end and a proximal end portion of the tubular engagement portion, the arrangement of circumferential ribs comprising at least one elongated flat circumferential rib and at least one barbed circumferential rib on each side of each elongated flat rib; and,

c. a crimping sleeve for overlying on the tubular engagement portion;

wherein the arrangement of circumferential ribs are configured to sealingly engage the pipe when the pipe is crimped on the tubular engagement portion and the crimping sleeve.
2. An O-ring-free plumbing fitting according to claim 1, wherein there are two such elongated flat circumferential ribs.
3. An O-ring free plumbing fitting according to claim 1 or 2, wherein there are two or more barbed circumferential ribs on each side of each elongated flat rib.
4. An O-ring-free plumbing fitting according to any one of the preceding claims, wherein the tubular engagement portion comprises an annular land proximally of the arrangement of circumferential ribs, the annular land having the same diameter as the arrangement of circumferential ribs.
5. An assembly comprising a plumbing fitting according to any one of claims 1 to 4 with a pipe end portion sealingly secured on the tubular engagement portion by the crimping sleeve, wherein the crimping sleeve provides crimping pressure points on the pipe end portion that are offset from the or each elongate flat circumferential rib on the tubular engagement portion.