Patent Description:
Plumbing fittings are used to connect plumbing lines to one another or to other plumbing components and the like. Some plumbing fittings incorporate a releasable mechanism that allows a user to disconnect the fitting from a plumbing line or component. Other fittings may incorporate mechanisms which allow the fitting itself to be disassembled, or require the fitting itself to be disassembled to allow a connected plumbing line or component to be disconnected from the fitting.

In either case, these mechanisms often require complex assemblies with many moving parts. Further, these mechanisms may allow one to tamper with the fitting or connected components, making the fitting and connected components susceptible to damage or theft.

<CIT> discloses a connector for a fuel tank includes a cylindrical main body; a connecting cylinder body including an attachment portion of a pipe connecting the fuel tank and an external portion, and assembled with the cylindrical main body; and a reinforcing cylinder body housed inside the connecting cylinder body, wherein the reinforcing cylinder body is sandwiched from both sides so that the reinforcing cylinder body is positioned on an inside of the attachment portion of the connecting cylinder body.

<CIT> discloses a quick connector, the quick connector comprising a sleeve joint part and a sliding lock. The sleeve joint part comprises a stop part, and the stop part is configured to stop the automatic moving of the sliding lock toward the interior of the sleeve joint part in the transverse direction in the period when a fluid pipeline is inserted into the sleeve joint part, and release the stopping of the sliding black when the pipeline is completely pushed into the main body of the sleeve joint part.

<CIT> discloses a connector for connecting respiratory ducts together such that they are placed in fluid communication, the connector comprising, a first conduit having a female connector end; and a second conduit having a male connector end adapted to be received within the female connector end of the first conduit, wherein the male connector has a retaining formation which is adapted to abut a corresponding formation on the female connector so as to resist separation.

Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.

It is an object of at least preferred embodiments of the present invention to provide a plumbing fitting which is simple in construction and substantially tamper-proof, and/or to at least provide the public with a useful alternative.

In a first aspect of the invention, there is provided a plumbing fitting comprising: a cap; and a body comprising a fitting end that is configured to be received by the cap, the body comprising a first engagement projection and a second engagement projection that are circumferentially spaced apart from each other and that extend radially outwardly from an outer circumferential surface of the fitting end; wherein the cap comprises: a first tab and a second tab, each tab having a free end at a receiving end of the cap; the first tab comprising a first receiver that is configured to receive the first engagement projection and the second tab comprising a second receiver that is configured to receive the second engagement projection; wherein the tabs are configured to permit flexure of each tab relative to the other; and wherein each tab comprises a radially inwardly extending spacer member at the free end of the tab; wherein the spacer members are configured such that, as the fitting end is received by the cap, the free end of each of the tabs is displaced radially outwardly so as to space apart an inner circumferential surface of the tabs from the outer circumferential surface of the fitting end, thereby providing clearance for receipt of the engagement projections by the receivers.

In some embodiments, the fitting end comprises a spacer receiving section configured to receive the spacer members so as to permit the free end of each of the tabs to displace radially inwardly thereby bringing together the inner circumferential surface of the tabs with the outer circumferential surface of the fitting end.

In some embodiments, receipt of the engagement projections by the receivers together with receipt of the spacer members by the spacer receiving section together provide a substantially non-releasable coupling of the cap to the body.

In some embodiments, each receiver and respective engagement projection are together configured to substantially inhibit longitudinal translation and/or axial rotation of the cap relative to the body when the receiver receives the respective engagement projection.

In some embodiments, the spacer receiving section and the spacer members are together configured to substantially inhibit longitudinal translation and/or axial rotation of the cap relative to the body when the spacer members are received by the spacer receiving section.

In some embodiments, the body comprises at least one engagement ridge extending longitudinally along and radially outwardly from the outer circumferential surface of the fitting end and configured to engage between adjacent tabs.

In some embodiments, the at least one engagement ridge is configured to substantially inhibit axial rotation of the cap relative to the body when the at least one engagement ridge is engaged between the adjacent tabs.

In some embodiments, the spacer receiving section comprises at least one inward ledge extending radially inwardly from the outer circumferential surface of the fitting end.

In some embodiments, the spacer receiving section comprises a substantially annular engagement channel extending radially inwardly from the outer circumferential surface of the fitting end.

In some embodiments, the at least one engagement ridge is configured to engage in a slot between the adjacent tabs.

In some embodiments, the first receiver and second receiver each comprise a receiver aperture extending through a radial thickness of the first and second tabs respectively.

In some embodiments, the spacer members are circumferentially offset from the first and second receivers.

In some embodiments, the slot is circumferentially offset from the first and second receivers.

In some embodiments, the body comprises: a third engagement projection and a fourth engagement projection circumferentially spaced apart from the first and second engagement projections and extending radially outwardly from the outer circumferential surface of the fitting end; and wherein the cap comprises: a third tab and a fourth tab each having a free end at the receiving end of the cap; the third tab comprising a third receiver that is configured to receive the third engagement projection and the fourth tab comprising a fourth receiver that is configured to receive the fourth engagement projection; wherein the third tab and the fourth tab each comprise a radially inwardly extending spacer member at the free end of the third tab and fourth tab respectively.

In some embodiments, the body comprises a bore extending from the fitting end and longitudinally through the body and configured to receive a plumbing assembly and wherein the cap comprises a plumbing aperture configured to receive a plumbing line couplable to the plumbing assembly.

In some embodiments, receipt of the of the plumbing line by the plumbing aperture, coupling of the plumbing line to the plumbing assembly, receipt of the plumbing assembly by the bore and coupling of the cap to the body together provide a substantially fluidly-sealed connection of the plumbing line to the plumbing fitting.

The term 'comprising' as used in this specification and claims means 'consisting at least in part of'. When interpreting statements in this specification and claims which include the term 'comprising', other features besides the features prefaced by this term in each statement can also be present. Related terms such as 'comprise' and 'comprised' are to be interpreted in a similar manner.

It is intended that reference to a range of numbers disclosed herein (for example, <NUM> to <NUM>) also incorporates reference to all rational numbers within that range (for example, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and <NUM>) and also any range of rational numbers within that range (for example, <NUM> to <NUM>, <NUM> to <NUM> and <NUM> to <NUM>) and, therefore, all sub-ranges of all ranges expressly disclosed herein are hereby expressly disclosed. These are only examples of what is specifically intended and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more said parts, elements or features.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting. Where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

As used herein the term '(s)' following a noun means the plural and/or singular form of that noun.

As used herein the term 'and/or' means 'and' or 'or', or where the context allows both. The invention consists in the foregoing and also envisages constructions of which the following gives examples only.

The present invention will now be described by way of example only and with reference to the accompanying drawings in which:.

<FIG> shows an illustrative embodiment of a plumbing fitting <NUM> in its assembled state. The plumbing fitting <NUM> may be used to provide fluid communication between plumbing lines, or plumbing features and devices such as valves, tanks, control systems and the like. Reference to a 'plumbing application' or 'plumbing system' in this specification may encompass any system that conveys fluids, such as, for example, a domestic or commercial heating and cooling system, a domestic or commercial hot or cold water system, an industrial waste removal system, an automotive coolant system, and any other fluid conveying system conceivable by one skilled in the art.

Further, the plumbing fitting <NUM> providing fluid communication may encompass fluid comprising any liquid, any liquid/gas mixture, any gas, or any substantially liquid mixture containing solid particulates or the like.

The plumbing fitting <NUM> may optionally be formed from deformable materials such as plastics, or a range of metal or metal alloys, as described below, and can thus be configured to couple to plumbing lines or features comprising a range of materials, such as plastic hose lines, braided hoses, brass/copper hoses, as well as any other metallic or non-metallic plumbing feature or device.

The plumbing fitting <NUM> is shown with two caps <NUM> assembled on opposing ends of a single body <NUM>. These opposing ends of the body <NUM> comprise fitting ends <NUM> to which the caps <NUM> can be coupled.

It should be noted that this body <NUM> shown in <FIG> is only one example configuration of the body <NUM>. The body <NUM> may instead comprise only one fitting end <NUM>, with the other end of the body <NUM> forming part of a plumbing component such as a valve, or integrally formed with a wall or other structural feature through which a plumbing line <NUM> fitted to the plumbing fitting <NUM> passes. The body <NUM> may also instead comprise a tee-junction, or four-way junction, or any other suitable intermediate plumbing junction, having a plurality of fitting ends <NUM> for connecting a plurality of plumbing lines, as described in further detail below. The body may be substantially straight between the fitting ends <NUM> as shown in <FIG>, or alternatively could have one end angularly offset from the other end in an elbow configuration such as shown in <FIG> for example.

Therefore, while the illustrative embodiments of the plumbing fitting <NUM> shown in <FIG> will be used throughout this specification to describe the principle functions and features of the plumbing fitting <NUM>, various other embodiments of the plumbing fitting <NUM>, and in particular adaptations and modifications to the cap <NUM> and body <NUM>, may be contemplated by a person skilled in the art to suit different plumbing components and applications without departing from the scope of the invention.

The following embodiments of pluming fitting will be described with reference to one cap <NUM> and one fitting end <NUM>. It will be appreciated in at least some embodiments the plumbing fitting will have a plurality of the fitting ends <NUM> and caps <NUM>, and like reference numbers indicate like parts.

<FIG> and <FIG> show the plumbing fittings <NUM> in a disassembled state. The plumbing fitting <NUM> comprises a cap <NUM> and a body <NUM>. The body <NUM> comprises a fitting end <NUM> that is configured to be received by the cap <NUM>. The body also comprises a first engagement projection <NUM> and a second engagement projection <NUM> (not visible in <FIG>, but shown in <FIG>) that are circumferentially spaced apart from each other, and that extend radially outwardly from an outer circumferential surface <NUM> of the fitting end <NUM>.

The cap <NUM> comprises a first tab <NUM> and a second tab <NUM>, each tab respectively having a free end <NUM>, <NUM> at a receiving end <NUM> of the cap <NUM>. The receiving end <NUM> of the cap <NUM> is substantially open so as to receive the fitting end <NUM> of the body <NUM>. The first tab <NUM> comprises a first receiver <NUM> that is configured to receive the first engagement projection <NUM> and the second tab <NUM> comprises a second receiver <NUM> that is configured to receive the second engagement projection <NUM>.

The body <NUM> shown in <FIG> also comprises third and fourth engagement projections <NUM>', <NUM>', and the cap <NUM> shown in <FIG> also comprises third and fourth tabs <NUM>', <NUM>' with corresponding receivers <NUM>', <NUM>'. The third engagement projection <NUM>' and fourth engagement projection <NUM>' are circumferentially spaced apart from the first and second engagement projections <NUM>, <NUM> and also extend radially outwardly from the outer circumferential surface <NUM> of the fitting end <NUM>. Further, the third tab and fourth tab <NUM>', <NUM>' each have a free end <NUM>', <NUM>' at the receiving end <NUM> of the cap <NUM>, with the third tab <NUM>' comprising a third receiver <NUM>' that is configured to receive the third engagement projection <NUM>' and the fourth tab <NUM>' comprising a fourth receiver <NUM>' that is configured to receive the fourth engagement projection <NUM>'. The third tab <NUM>' and the fourth tab <NUM>' also each comprise a radially inwardly extending spacer member <NUM>', <NUM>' at the free end of the third tab <NUM>' and fourth tab <NUM>' respectively.

However, in some configurations, the cap <NUM> may comprise anywhere from two to eight, or even more tabs <NUM>, <NUM>', <NUM>, <NUM>' and corresponding receivers <NUM>, <NUM>', <NUM>, <NUM>', and the body <NUM> may likewise comprises anywhere from two to eight, or even more, corresponding engagement projections <NUM>, <NUM>', <NUM>, <NUM>'. This applies equally to many other components of the cap <NUM> and body <NUM> described in further detail below that correspond to, or are arranged on, those respective features. Therefore, any description of the functions and features of the first and second engagement projections, tabs, receivers, or other components/features corresponding to or arranged thereon, may apply equally to third, fourth, fifth etc. engagement projections, tabs, receivers, or other components/features corresponding to or arranged thereon, and the like. Like reference numbers indicate like parts with an addition of a prime (').

Therefore, while <FIG> illustrate a 'four-tab' embodiment of the plumbing fitting <NUM>, reference will be made predominately to the first and second of the respective engagement projections, tabs, receivers, and components/features corresponding to or arranged thereon in this specification.

<FIG> show detailed views of the cap <NUM>. The first and second tabs <NUM>, <NUM> are configured to permit flexure of each tab relative to the other. In this way, each tab <NUM>, <NUM> of the cap <NUM> can move, flex, or deform relative to one another and relative to the substantially rigid cone end <NUM> of the cap <NUM>. In particular, the free end <NUM> of the first tab <NUM> and the free end <NUM> of the second tab <NUM> (and the free ends <NUM>', <NUM>' of the any other tabs <NUM>', <NUM>'), can displace radially outwardly, and optionally radially inwardly, relative to their default circumferential positions shown in <FIG>. The features of the cap <NUM> that provide this functionality are described in further detail below.

Each tab <NUM>, <NUM> also comprises a radially inwardly extending spacer member <NUM>, <NUM> at the free end <NUM>, <NUM> of the tab <NUM>, <NUM>. In the embodiment shown, the first tab <NUM> has two spacer members <NUM>, <NUM> arranged on either lateral end of the first tab <NUM>, and likewise, the second tab <NUM> has two spacer members <NUM>, <NUM> arranged on either lateral end of the second tab <NUM>. However, in some configurations, each tab may have only one spacer member, or any suitable plurality of spacer members extending from the free end of the tab. Reference made to the features and functions of the spacer members <NUM>, <NUM> apply equally to spacer members <NUM>, <NUM>.

Each tab <NUM>', <NUM>' also has at least one radially inwardly extending spacer member <NUM>', <NUM>' at the free end <NUM>', <NUM>' of the tab <NUM>', <NUM>'. The variants for the spacer member(s) is/are as outlined in the preceding paragraph.

The spacer members <NUM>, <NUM> are configured such that, as the fitting end <NUM> is received by the cap <NUM>, the free end <NUM>, <NUM> of each of the tabs <NUM>, <NUM> is displaced radially outwardly from their default circumferential positions shown in <FIG>. The spacer members <NUM>, <NUM> are configured as such so as to space apart an inner circumferential surface <NUM> of the tabs <NUM>, <NUM> from the outer circumferential surface <NUM> of the fitting end <NUM>, as the fitting end <NUM> is received by the cap <NUM>. This provides clearance for travel of the receivers <NUM>, <NUM> over the respective engagement projections <NUM>, <NUM>, due to the radially outward displacement as shown in <FIG>.

The plumbing fitting <NUM> is thereby configured so that the dimensions of the cap <NUM> and body <NUM> and their respective features correspond to one another so as to require spacing apart of the inner circumferential surface <NUM> from the outer circumferential surface <NUM> to provide clearance for travel of the receivers <NUM>, <NUM> over the respective engagement projections <NUM>, <NUM>.

This is best illustrated in <FIG>, where <FIG> show cross sectional views of the body <NUM>, <FIG> shows a rear view of the cap <NUM>, and <FIG> and <FIG> show cross sectional views of the plumbing fitting <NUM> in its disassembled state. As can be seen in <FIG>, the plumbing fitting <NUM> is dimensioned such that the diameter D1 of the outer circumferential surface <NUM> of the fitting end <NUM> is substantially equal to the diameter D3 of the inner circumferential surface <NUM> of the tabs <NUM>, <NUM>. Thus, receipt of the fitting end <NUM> by the cap <NUM> represents a tight-interference fit in which substantial force is required to press the fitting end <NUM> of the body <NUM> into the receiving end <NUM> of the cap <NUM>. Such a fitment typically results in coupling of parts that is predominantly secured through friction between the surfaces of the parts.

Therefore, once the cap <NUM> receives the fitting end <NUM>, the resulting friction between the outer circumferential surface <NUM> of the fitting end <NUM> and the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> assists in preventing the cap <NUM> from being easily removable from the body <NUM> by simply pulling apart the two along the axial longitudinal direction of the plumbing fitting <NUM>.

In the exemplary embodiment of <FIG>, the first receiver <NUM> and second receiver <NUM> each comprise a receiver aperture extending through the circumferential thickness D7 of the first and second tabs <NUM>, <NUM> respectively. The circumferential thickness D7 is in a radial direction, so can alternatively be considered a radial thickness.

In that embodiment, the circumferential height D5 of each of the engagement projections <NUM>, <NUM> (shown in <FIG>) is dimensioned to be substantially equal to, or greater than, the circumferential thickness D7 of the tabs <NUM>, <NUM> (shown in <FIG>). In this way, the tabs <NUM>, <NUM> require clearance above this height D5 in order for the receivers <NUM>, <NUM> to receive the projections <NUM>, <NUM>. The circumferential height D5 is in a radial direction, so can alternatively be considered a radial height.

However, in some configurations, the receivers <NUM>, <NUM> may instead comprise recesses extending radially outwardly from the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> into the thickness D7 of the tabs <NUM>, <NUM>, but not through the full circumferential thickness D7. In such an embodiment, the circumferential height D5 of each of the engagement projections <NUM>, <NUM> will instead by dimensioned to be substantially equal to, but not greater than, the circumferential thickness D7 of the tabs <NUM>, <NUM>.

It should be noted that, in some embodiments, regardless of whether the receivers <NUM>, <NUM> comprise apertures or recesses, the circumferential height D5 of each of the engagement projections <NUM>, <NUM> may also be less than the circumferential thickness D7 of the tabs <NUM>, <NUM>.

In any case, the circumferential depth D9 of the spacer members <NUM>, <NUM> (shown in <FIG>) is configured to be substantially equal to, or greater than, the circumferential height D5 each of the engagement projections <NUM>, <NUM>, so as to permit sufficient outward radial displacement of the free ends <NUM>, <NUM> of each of the tabs <NUM>, <NUM>. The circumferential depth D9 is in a radial direction, so can alternatively be considered a radial depth.

This outward radial displacement of the free ends <NUM>, <NUM> of each of the tabs <NUM>, <NUM> may also be assisted through provision of an annular chamfer <NUM> at a periphery of the fitting end <NUM>, shown in <FIG> and <FIG>. The spacer members <NUM>, <NUM> will undergo a gradual initial outward displacement as they ride over the taper of the annular chamfer <NUM>, helping the free ends <NUM>, <NUM> of the tabs <NUM>, <NUM> to move from their default position shown in <FIG> to the required outward radial displacement.

This may also be assisted through provision of an engagement projection chamfer <NUM> at an edge of one or each of the engagement projections <NUM>, <NUM>, shown in <FIG> and <FIG>. The free ends <NUM>, <NUM> of the tabs <NUM>, <NUM>, already outwardly displaced by the interaction between the spacer members <NUM>, <NUM> and the outer circumferential surface <NUM> of the fitting end <NUM> (and optionally the interaction with the annular chamfer <NUM>) may undergo an additional, final outward displacement as they ride over the taper of the engagement projection chamfer(s) <NUM>.

It should be noted that the substantially rectangular shapes of the engagement projections <NUM>, <NUM> shown in <FIG> are illustrative examples only, and that the engagement projections <NUM>, <NUM> may take other forms and shapes as long as they fulfil their intended function. For instance, the engagement projections <NUM>, <NUM> may instead take a wedge-shape that tapers in the direction of the periphery of the fitting end <NUM>, or be outwardly concave or convex in the direction of the periphery of the fitting end <NUM>, regardless of whether or not they are provided with the optional engagement projection chamfer(s) <NUM>. In any case, the engagement projections <NUM>, <NUM> will typically have an inner ledge <NUM> that contacts a corresponding internal wall of the respective receiver <NUM>, <NUM> to substantially inhibit outward longitudinal translation of the cap <NUM> relative to the body <NUM> when the cap <NUM> is coupled thereto.

Therefore, the required radial outward displacement of the free ends <NUM>, <NUM> of each of the tabs <NUM>, <NUM> (and thus the subsequent spacing apart of the inner circumferential surface <NUM> from the outer circumferential surface <NUM>), is achieved predominately through the provision and appropriate configuration of the spacer members <NUM>, <NUM> but may be further assisted by provision of the annular chamfer <NUM> or engagement projection chamfer(s) <NUM>.

Once the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> is spaced apart from the outer circumferential surface <NUM> of the fitting end <NUM>, the fitting end <NUM> may proceed past the receiving end <NUM> of the cap <NUM> further into the interior of the cap <NUM>, until the receivers <NUM>, <NUM> travel over and align with the engagement projections <NUM>, <NUM>.

However, in order for the engagement projections <NUM>, <NUM> to be received by the receivers <NUM>, <NUM>, the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> must return to its default position in contact with the outer circumferential surface <NUM> of the fitting end <NUM>.

To this end, the fitting end <NUM> comprises a spacer receiving section configured to receive the spacer members <NUM>, <NUM> so as to permit the free end <NUM>, <NUM> of each of the tabs <NUM>, <NUM> to displace radially inwardly, from their radially outwardly displaced positions, thereby bringing together the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> with the outer circumferential surface <NUM> of the fitting end <NUM>, once the cap <NUM> is fully inserted onto the fitting end <NUM>.

The spacer receiving section comprises a substantially annular engagement channel <NUM> shown in <FIG>, <FIG> and <FIG>, extending radially inwardly from the outer circumferential surface <NUM> of the fitting end <NUM>. The substantially annular engagement channel <NUM> is shown comprising a plurality of discrete annular engagement channels, divided by engagement ridges <NUM> described in further detail below. In particular, there are four annular engagement channels <NUM>, each corresponding to a respective one of the tabs <NUM>, <NUM>', <NUM>, <NUM>'.

However, in some configurations there may be any number of discrete annular engagement channels corresponding to each, or multiple of, the spacer members <NUM>, <NUM>. Further, in some configurations (without engagement ridges <NUM>, or with engagement ridges <NUM> that do not extend through the substantially annular engagement channel <NUM>), the annular engagement channel <NUM> may instead extend continuously and uninterrupted around the entire circumference of the fitting end <NUM>.

Further, in other configurations, the spacer receiving section may instead comprise at least one inward ledge extending radially inwardly from the outer circumferential surface <NUM> of the fitting end <NUM>. The at least one inward ledge may for example take a form similar to that of the internal wall <NUM> of the annular engagement channel <NUM>. If multiple inward ledges are provided, each may correspond to each, or multiple of, the spacer members <NUM>, <NUM>. However in some configurations, the inward ledge may instead extend continuously around the entire circumference of the fitting end <NUM>.

In any case, the spacer receiver section is dimensioned so as to correspond to the circumferential depth D9 of the spacer members <NUM>, <NUM>. This is shown in <FIG> and <FIG>, wherein the circumferential depth D11 of the substantially annular engagement channel <NUM> (shown in <FIG>) is equal to, or greater than, the circumferential depth D9 (shown in <FIG>) of the spacer members <NUM>, <NUM>.

This allows the entirety of the spacer members <NUM>, <NUM> to be received by the substantially annular engagement channel <NUM>, thereby allowing the inner circumferential surface <NUM> of the tabs <NUM>, <NUM> to return to contact the outer circumferential surface <NUM> of the fitting end <NUM>. Consequently, the entirety of the engagement projections <NUM>, <NUM> are received by the receivers <NUM>, <NUM>.

The spacer receiver section, whether comprising the substantially annular engagement channel <NUM>, at least one inward ledge, or combinations/configurations thereof as outlined above, may define an edge or periphery of the fitting end <NUM>. In this way, the length D8 of the cap <NUM> corresponds to the length D10 of the fitting end <NUM>, as shown in <FIG>. This, together with appropriate configuration of dimensions D1, D3, D9, D11 substantially constrains the fitting end <NUM> within the interior of the cap <NUM>.

When the fitting end <NUM> is fully received by the cap <NUM>, there is substantially no free space between the inner circumferential surface <NUM> and the outer circumferential surface <NUM>, between the periphery of the fitting end <NUM> (whether it includes the optional annular channel <NUM>) and an interior chamfer <NUM> of the cap <NUM>, and between spacer members <NUM>, <NUM> and the (internal wall <NUM> of the) substantially annular engagement channel <NUM> (or the at least one inward ledge), as shown in <FIG>.

Thus, when the fitting end <NUM> is fully received by the cap <NUM>, appropriate configurations of dimensions D8 and D10 as well as other dimensions D1, D3, D9, D11 helps to substantially inhibit movement of the cap <NUM> relative to the body <NUM> due to friction between these contacting surfaces/features, thereby helping to prevent removal of the cap <NUM> from the body <NUM>.

However, the main features of the plumbing fitting <NUM> responsible for preventing removal of the cap <NUM> from the body <NUM> once coupled together are the engagement projections <NUM>, <NUM> together with the receivers <NUM>, <NUM>, and the spacer members <NUM>, <NUM> together with the spacer receiving section.

Receipt of the engagement projections <NUM>, <NUM> by the receivers <NUM>, <NUM> together with receipt of the spacer members <NUM>, <NUM> by the spacer receiving section (comprising the substantially annular engagement channel <NUM>) together provide a substantially non-releasable coupling of the cap <NUM> to the body <NUM>.

Therefore, a user attempting to pull apart the cap <NUM> from the body <NUM> through application of force along an axial longitudinal direction is prevented from doing so thanks to the engagement projections <NUM>, <NUM> and the spacer members <NUM>, <NUM> concurrently pressing against respective enclosing surfaces, of the receivers <NUM>, <NUM> and the substantially annular engagement channel <NUM>, that constrain the engagement projections <NUM>, <NUM> and the spacer members <NUM>, <NUM> therein.

As such, the receivers <NUM>, <NUM> and the substantially annular engagement channel <NUM> are dimensioned appropriately with respect to the engagement projections <NUM>, <NUM> and the spacer members <NUM>, <NUM> to constrain and enclose them in a way that substantially inhibits movement of the cap <NUM> relative to the body <NUM>, once the fitting end <NUM> is received by the cap <NUM>.

For instance, the length D13 (shown in <FIG>) of the engagement projections <NUM>, <NUM> is substantially equal to the length D15 (shown in <FIG>) of the receivers <NUM>, <NUM>. In this way, once the engagement projections <NUM>, <NUM> are received by the receivers <NUM>, <NUM>, the cap <NUM> is substantially inhibited from translation in the longitudinal direction, as both longitudinal ends of the engagement projections <NUM>, <NUM> are constrained by respective longitudinal internal walls of the receivers <NUM>, <NUM>.

In some configurations, such as the exemplary embodiment of <FIG>, the width D17 (shown in <FIG>) of the engagement projections <NUM>, <NUM> may also be substantially equal to the width D19 (shown in <FIG>) of the receivers <NUM>, <NUM>. In this way, once the engagement projections <NUM>, <NUM> are received by the receivers <NUM>, <NUM>, the cap <NUM> is substantially inhibited from rotation about the longitudinal direction, as both lateral ends of the engagement projections <NUM>, <NUM> are constrained by respective lateral internal walls of the receivers <NUM>, <NUM>.

Therefore, each receiver <NUM>, <NUM> and respective engagement projection <NUM>, <NUM> are together configured to substantially inhibit longitudinal translation and/or axial rotation of the cap <NUM> relative to the body <NUM> when the receiver <NUM>, <NUM> receives the respective engagement projection <NUM>, <NUM>.

Further, the width D21 (shown in <FIG>) of the substantially annular engagement channel <NUM> is substantially equal to the width D23 (shown in <FIG>) of the spacer members <NUM>, <NUM>. In this way, once the spacer members <NUM>, <NUM> are received by the substantially annular engagement channel <NUM>, the cap <NUM> is substantially inhibited from translation in the longitudinal direction, as both longitudinal ends of the spacer members <NUM>, <NUM> are constrained by respective longitudinal internal walls (including the internal wall <NUM>) of the substantially annular engagement channel <NUM>.

Further, in some configurations, when one spacer member is provided on a tab, the circumferential length D25 (shown in <FIG>) of a given discrete channel of the substantially annular engagement channel <NUM> may correspond to the circumferential length D27 (shown in <FIG>) of that spacer member. In that way, both sides of that spacer member are enclosed and constrained by respective lateral internal walls of that discrete channel of the substantially annular engagement channel <NUM>.

However, if two or more spacer members are arranged on a tab, such as in the embodiment of <FIG>, the circumferential length D25 of a given discrete channel of the substantially annular engagement channel <NUM> may instead correspond to the circumferential length D29 (shown in <FIG>) between the positions of the two outermost spacer members of that tab (spacer members <NUM>, <NUM> for first tab <NUM>, or spacer members <NUM>, <NUM> of second tab <NUM>). In this way, once the spacer members are received by the annular engagement channel <NUM>, the cap <NUM> is substantially inhibited from rotation about the longitudinal direction, as the outermost lateral end of the outermost spacer members is constrained by respective lateral internal walls of that given discrete channel of the substantially annular engagement channel <NUM>.

Therefore, the spacer receiving section and the spacer members <NUM>, <NUM> are together configured to substantially inhibit longitudinal translation and/or axial rotation of the cap <NUM> relative to the body <NUM> when the spacer members are received by the spacer receiving section.

For instance, in the exemplary embodiment of <FIG>, the circumferential length D25 of a given discrete channel of the substantially annular engagement channel <NUM> is not equal to the circumferential lengths D27 of the spacer members <NUM>, <NUM>. However, the circumferential lengths D25 are nonetheless configured to correspond to the circumferential length D29 between the positions of the two outermost spacer members <NUM>, <NUM> of the first tab <NUM> and outermost spacer member <NUM>, <NUM> of the second tab. In the exemplary embodiment of <FIG>, this circumferential length D29 also corresponds to and/or is defined by the provision of the engagement ridges <NUM> described below.

In this way, since this particular embodiment of the plumbing fitting <NUM> comprises two spacer members at lateral ends of each tab, the outermost lateral wall of the outermost spacer members of each tab contacts a respective lateral wall of each engagement ridge <NUM>, so as to substantially inhibit rotation about the longitudinal direction of the cap <NUM> relative to the body <NUM>. In some embodiments, where engagement ridges <NUM> are not provided, or where engagement ridges <NUM> do not extend through the substantially annular engagement channel <NUM>, the substantially annular engagement channel <NUM> may nonetheless possess inward lateral walls that constrain the spacer members of a given tab in the same manner as the engagement ridges <NUM>.

As can be seen in <FIG>, the body <NUM> comprises at least one engagement ridge <NUM> extending longitudinally along and radially outwardly from the outer circumferential surface <NUM> of the fitting end <NUM> and configured to engage between adjacent tabs. In the exemplary embodiment of <FIG>, the at least one engagement ridge <NUM> is configured to engage in a slot <NUM> between the adjacent tabs.

In the 'four-tab' embodiment of <FIG>, a slot <NUM> is provided on both lateral ends of the first tab <NUM>: between the first tab <NUM> and the third tab <NUM>' and between the first tab <NUM> and the fourth tab <NUM>'; as well as on both lateral ends of the second tab <NUM>, between the second tab <NUM> and the third tab <NUM>' and between the second tab <NUM> and fourth tab <NUM>'. However, in a 'two-tab' embodiment having only a first and second tab <NUM>, <NUM>, a slot <NUM> may be provided on both lateral ends of the first tab <NUM> and the second tab <NUM>, between those two adjacent tabs.

In any case, regardless of whether the cap <NUM> comprises two to eight or more tabs, the at least one engagement ridge <NUM> is configured to engage between any two adjacent tabs (or a slot between any two adjacent tabs).

Further, in some configurations, the at least one engagement ridge <NUM> may engage with a discontinuous space between adjacent tabs, such as the slot <NUM>, an internal recess between adjacent tabs (or the like), or a deformable section between adjacent tabs. The deformable section may comprise a portion of material that is more flexible than the material from which the tabs are formed, or may comprise a portion of material defining or enclosing the recess, made of the same or a more flexible material than the material from which the tabs are formed. Further, in some configurations, the cap <NUM> may comprise a combination of slots, recesses or deformable sections or combinations/modifications thereof between adjacent tabs.

It should also be noted that regardless of the number of tabs, the circumferential lengths of the tabs, and their circumferential positions, can be configured so that the at least one engagement ridge <NUM> engages in a slot/recess/deformable section/or combinations/modifications thereof having any given circumferential length or thickness.

For instance, in a 'two-tab' embodiment, the first and second tabs <NUM>, <NUM> may have the same circumferential lengths and positions as the first and second tabs <NUM>, <NUM> shown in the 'four-tab' embodiment of <FIG>, with spaces between the first and second tabs <NUM>, <NUM> where the third and fourth tabs <NUM>', <NUM>' are shown; therefore, the at least one engagement ridge <NUM> would engage between the first and second tabs <NUM>, <NUM> in either of those spaces (having similar circumferential lengths as the third and fourth tabs <NUM>', <NUM>'), and those spaces may comprise a slot/recess/deformable section/or combinations/modifications thereof. However, in preferred embodiments, the circumferential lengths of the tabs are configured so as to extend substantially around the circumference of the cap <NUM>, in a similar manner to the 'four-tab' embodiment of <FIG>.

In any case, flexure of adjacent tabs relative to the other is permitted. In this way, regardless of whether a slot, a recess, a deformable section, or combinations/modifications thereof is provided between adjacent tabs, each tab is able to move, flex, or deform relative to one another and relative to the substantially rigid cone end <NUM> of the cap <NUM>. In particular, the slot/recess/deformable section/or combinations/modifications thereof between adjacent tabs should extend from the receiving end <NUM> of the cap <NUM> into a substantial length of the cap <NUM>, so as to permit enough flexibility for the free ends <NUM>, <NUM> of the tabs to displace radially inwardly or outwardly relative to their default circumferential positions shown in <FIG>. The length of the slot/recess/deformable section/or combinations/modifications thereof between adjacent tabs thereby substantially defines the length of each tab.

In the exemplary embodiments of <FIG>, there are four engagement ridges <NUM> that correspond to four slots <NUM>. The slots <NUM>, and the at least one engagement ridge <NUM> are dimensioned respectively so as to provide constrained enclosure of the engagement ridges <NUM> by the slots <NUM>.

For instance, the circumferential thickness D31 (shown in <FIG>) of the at least one engagement ridge <NUM> is substantially equal to the circumferential thickness D33 (shown in <FIG>) of the slot <NUM> between the adjacent tabs. In this way once the at least one engagement ridge <NUM> is received by the slot <NUM> between the adjacent tabs, the cap <NUM> is substantially inhibited from rotation about the longitudinal direction, as one of, or both lateral sides of at least one engagement ridge <NUM> is constrained by respective internal lateral walls of the slot <NUM> between the adjacent tabs.

Therefore, the at least one engagement ridge <NUM> is configured to substantially inhibit axial rotation of the cap <NUM> relative to the body <NUM> when the at least one engagement ridge <NUM> is engaged between the adjacent tabs (or engaged in a slot <NUM> between adjacent tabs).

In addition to the configuration of dimensions D1-D33, the positions of the various features of the cap <NUM> and body <NUM> correspond to one another so as to provide a coupling that may be easily and quickly aligned.

For instance, since the receivers <NUM>, <NUM> are configured to receive the engagement projections <NUM>, <NUM>, the positions of the receivers <NUM>, <NUM> appropriately correspond to the positions of the engagement projections <NUM>, <NUM>. Likewise, since the slots <NUM> are configured to receive the at least one engagement ridge <NUM>, the positions of the engagement ridges <NUM> appropriately correspond to the positions of the slots <NUM>. Finally, since the spacer receiver section comprising the substantially annular engagement channel <NUM> is configured to receive the spacer members <NUM>, <NUM>, <NUM>, <NUM>, the positions of the discrete engagement channels <NUM> appropriately correspond to the positions of the spacer members <NUM>, <NUM>, <NUM>, <NUM>.

As a result, because the positions of the receivers <NUM>, <NUM> correspond to the positions of the engagement projections <NUM>, <NUM>, the spacer members <NUM>, <NUM>, <NUM>, <NUM> are circumferentially offset from the first and second receivers <NUM>, <NUM>. This ensures that the spacer members <NUM>, <NUM>, <NUM>, <NUM> do not contact or abut against the engagement projections <NUM>, <NUM> during receipt of the fitting end <NUM> by the cap <NUM>.

It should be noted that, as described above, each tab need only comprise one spacer member, however if two or more spacer members are provided on a given tab, they must be arranged so as to be circumferentially offset from the receiver of that tab for the same reason.

Further, since the positions of the engagement ridges <NUM> correspond to the positions of the slots <NUM>, the slot <NUM> is circumferentially offset from the first and second receivers <NUM>, <NUM>. This ensures that the engagement ridges <NUM> do not contact the first and second receivers <NUM>, <NUM> during receipt of the fitting end <NUM> by the cap <NUM>.

Finally, the first and second engagement projections <NUM>, <NUM>, as well as the third and fourth (or fifth, sixth, seventh etc.) engagement projections are all circumferentially spaced apart from one another.

Thus, the various features of the cap <NUM> and body <NUM> are shown correspondingly arranged about the circumferences of the cap <NUM> and body <NUM> to respectively interface with one another. Further, since the various features of the cap <NUM> are arranged on, or correspond to a given tab, the cap <NUM> can be axially rotated to align any one given tab having its various features, with any one given engagement projection and the features of the fitting end <NUM> proximal that engagement projection.

This results in tabs that are configured in a circumferentially symmetric manner. For instance, for the exemplary embodiment of <FIG>, a user may easily rotate either the cap <NUM> or the body <NUM> about <NUM> degrees to align any one given tab of the cap <NUM> having its various features with any one given engagement projection of the body <NUM>, to thereby and quickly and easily couple them together. This applies equally to configurations of the plumbing fitting <NUM> wherein the cap <NUM> instead comprises an odd number of tabs, for instance a cap <NUM> having three tabs and therefore instead requiring about <NUM> degree rotations to align features of the cap <NUM> with the fitting end <NUM> of the body <NUM>.

Therefore, the plumbing fitting <NUM>, through provision of engagement projections <NUM>, <NUM>, receivers <NUM>, <NUM>, spacer members <NUM>, <NUM>, spacer receiver sections (substantially annular engagement channel <NUM>) and optionally, engagement ridges <NUM> and slots <NUM> between each tab, provides a substantially non-releasable coupling of the cap <NUM> to the body <NUM>. This in turn, prevents the plumbing fitting <NUM> from being easily disassembled, damaged or tampered with, providing security for the plumbing lines connected thereto, as well as features of the plumbing assembly <NUM> (described in further detail below) enclosed by the plumbing fitting <NUM>.

Further, the cap <NUM> and its various features, are preferably integrally formed from a uniform material, as is the body <NUM> and its various features. Therefore, the plumbing fitting <NUM> provides such a substantially non-releasable and tamper-proof coupling, without the need for complex assemblies with many moving parts.

Preferably, the material comprises a deformable material such as moulded plastic or the like. Alternatively, the material may comprise aluminium, aluminium alloy(s), brass, brass alloy(s), steel, stainless steel, steel alloy(s), or any other suitable metal or metal alloy(s). In this way, when the spacer members <NUM>, <NUM> are displaced radially outwardly during receipt of the fitting end <NUM> by the cap <NUM>, then subsequently received by the spacer receiving section, the free ends <NUM>, <NUM> of the tabs <NUM>, <NUM> return to their default positions of <FIG> so that the tabs <NUM>, <NUM> are only temporarily or elastically deformed during receipt of the fitting end <NUM> by the cap <NUM>.

Therefore, the provision of the features described above mean that the cap <NUM> is deformed elastically for a minimal period of time during use of the plumbing fitting <NUM>. As a result, after coupling of the cap <NUM> to the body <NUM>, the tabs <NUM>, <NUM> of the cap <NUM> substantially maintain their original integrity, rather than permanently or inelastically deforming the tabs <NUM>, <NUM> and therefore weakening the coupling of the cap <NUM> to the body <NUM>.

It should be noted that many of the shapes or forms shown of the various features of the cap <NUM> and body <NUM> (such as the engagement projections <NUM>, <NUM>, receivers <NUM>, <NUM>, annular chamfer <NUM>, spacer members <NUM>, <NUM>, engagement projection chamfer <NUM>, substantially annular engagement channel <NUM>, engagement ridges <NUM> and/or slots <NUM>) are illustrative examples only and may take other forms and shapes as long as they fulfil their intended function.

For instance, the engagement projections <NUM>, <NUM> and corresponding receivers <NUM>, <NUM> are shown having substantially rectangular shapes, however they may instead take wedge-shape, concave shape or convex shape as outlined above, for example, as long as that shape still comprises the dimensions D13, D15, D17, D19 of the engagement projections <NUM>, <NUM> and corresponding receivers <NUM>, <NUM> described above, as well as features such as the inner ledge <NUM> of the engagement projections <NUM>, <NUM> cooperating with internal walls of the receivers <NUM>, <NUM>, that causes engagement between the two to substantially inhibit longitudinal translation and/or axial rotation of the cap <NUM> relative to the body <NUM> when the receiver <NUM>, <NUM> receives the respective engagement projection <NUM>, <NUM>.

<FIG> shows an exploded view of an embodiment of the plumbing fitting <NUM> in use. This embodiment of the plumbing fitting <NUM> may have any one or more of features, functionality, and described for the embodiment of the plumbing fitting of <FIG>. As shown, when the body <NUM> comprises two fitting ends <NUM> on opposing ends of the body <NUM>, the plumbing fitting <NUM> can be used to connect a plumbing line <NUM> to another plumbing line <NUM>. However, in some instances as outlined above, the body <NUM> may instead comprise only one fitting end <NUM>, with the other end of the body <NUM> forming part of a plumbing component such as a valve, or integrally formed with a wall or other structural feature through which a plumbing line <NUM> fitted to the plumbing fitting <NUM> passes.

In any case, the body <NUM> comprises a bore <NUM> extending from the fitting end <NUM> and longitudinally through the body <NUM>. This bore <NUM> is configured to receive a plumbing assembly <NUM>. The cap <NUM> comprises a plumbing aperture <NUM> configured to receive a plumbing line <NUM> couplable to the plumbing assembly <NUM>. The plumbing assembly <NUM> is shown in its expanded state in <FIG> and comprises an O-ring <NUM>, an insert <NUM> and a grab-edge member <NUM>.

In use, the plumbing assembly <NUM> is first arranged within the bore <NUM> of the body <NUM>, then the plumbing line <NUM> run through the plumbing aperture <NUM> of the cap <NUM>. The open end <NUM> of the plumbing line <NUM> is passed through the grab-edge member <NUM> and the O-ring <NUM> to press around and receive the cylindrical body of the insert <NUM>, before the cap <NUM> is pushed onto the fitting end <NUM> of the body <NUM> so as to substantially non-releasably couple the cap <NUM> to the body <NUM>, and therefore enclose the plumbing assembly <NUM> and the open end <NUM> of the plumbing line <NUM> within the plumbing fitting <NUM>.

This substantially non-releasable coupling of the cap <NUM> to the body <NUM>, as outlined above, therefore prevents disassembly of the plumbing fitting <NUM> so as to protect the plumbing fitting <NUM>, and the plumbing assembly <NUM> and open end <NUM> of the plumbing line <NUM> enclosed therein, from tampering theft or damage. Further, the substantially no free space between the various features of the plumbing fitting <NUM> when connected, and in particular the flexible or deformable features such as the tabs <NUM>, <NUM> of the cap <NUM>, as described above, make it difficult to deform, pull-apart or displace those flexible features so as to forcibly remove the cap <NUM> from the body <NUM>. This prevents the particular plumbing application the plumbing fitting <NUM> is used in from becoming destabilised or damaged due to a change in, for example pressure, temperature or flow rate, that may be caused by tampering, theft or damage of the fitting <NUM>, and the plumbing assembly <NUM> and open end <NUM> of the plumbing line <NUM> enclosed therein.

It should be noted that the plumbing assembly <NUM> shown in <FIG> is only an illustrative example of a plumbing assembly <NUM>. The plumbing assembly <NUM> make take other suitable forms depending on, for instance, the material of the plumbing line <NUM>, the make-up of the fluid passing therethrough and/or the particular application in which the pluming fitting <NUM> is used. For instance, the plumbing assembly <NUM> may comprise more than one O-ring, an insert comprised of multiple moving parts such as a retainer or collet, or other features that those skilled in the art may contemplate when adapting the plumbing fitting <NUM> for a given application.

In any case, the plumbing assembly <NUM> shown in <FIG> comprising the grab-edge member <NUM> allows one to disconnect the plumbing line <NUM> from the plumbing fitting <NUM> without requiring disassembly of the plumbing fitting <NUM> itself. This may be achieved by simply pushing the edge of the grab-edge member <NUM> that protrudes from the plumbing aperture <NUM> further into the interior of the plumbing fitting <NUM> while simultaneously pulling and twisting the plumbing <NUM> line out from the interior of the plumbing fitting <NUM>, causing the grab-edge member <NUM> to release the open end <NUM> of the pluming line <NUM> from the insert <NUM> and thus allowing the plumbing line <NUM> to be pulled out from the plumbing aperture <NUM> of the cap <NUM>.

Other components that the grab-edge member <NUM> may be contemplated by those skilled in the art that may provide a similar function, or alternatively, may not allow the plumbing line <NUM> from being disconnected once the cap <NUM> is coupled to the body <NUM>.

It should also be noted that while the body <NUM> shown in <FIG> comprises two opposing ends with two fitting ends <NUM>, it may instead comprise a tee-junction having three ends, or a four-way junction having four ends, for example. In any case, the bore <NUM> may extend from one end to the other, or in the case of a body <NUM> having more than two ends, may extend to a junction between other bores of other ends. The body <NUM> therefore provides fluid communication between the plumbing line(s) connected thereto.

Further, each of these other ends may comprise a fitting end configured in substantially the same manner as the fitting end <NUM> described throughout this specification, and therefore be configured to be received by a cap configured in substantially the same manner as the cap <NUM> described throughout this specification. In this way, the body <NUM> may be configured to provide connection between a plurality of plumbing lines, with each connection being substantially non-releasable and thereby protected from tamper, damage and/or theft.

In one exemplary embodiment, the plumbing fitting <NUM> is configured such that the largest maximum diameter D35 of the plumbing fitting <NUM>, as shown in <FIG>, is about <NUM>. This largest maximum diameter D35 corresponds to the external diameter of the cap <NUM> as well as the body <NUM>, in the configuration shown in which they are substantially equal. The other dimensions D1-D33 in this exemplary embodiment have the following values: D1 <NUM>, D3 <NUM>, D5 <NUM>, D7 <NUM>, D8 <NUM>, D10 <NUM>, D9 <NUM>, D11 <NUM>, D13 <NUM>, D15 <NUM>, D17 <NUM>, D19 <NUM>, D21 <NUM>, D23 <NUM>, D25 <NUM>, D29 <NUM>, D27 <NUM>, D31 <NUM>, D33 <NUM>.

As such, numerical differences between the above pairs of dimensions that are described above as 'corresponding' or 'substantially equal' provides examples of the tolerances appropriate for this exemplary embodiment. For example, the circumferential depth D11 of the substantially annular engagement channel <NUM> is described above as equal to, or greater than, the circumferential depth D9 of the spacer members <NUM>, <NUM>. This can be seen listed above, where D9 is <NUM> and D11 is <NUM>.

Further, dimensions D8 and D10, D13 and D15, D17 and D19, D21 and D23, D25 and D29, are all described above as 'substantially equal', and as listed for the exemplary embodiment above, may have less than <NUM> of difference between each corresponding pair. By contrast, dimensions D1 and D3, D5 and D7, D31 and D33 have exact matching values. Differences between dimensions described as 'corresponding' or 'substantially equal' may be smaller or larger than those listed above.

In other embodiments of the plumbing fitting <NUM>, the largest maximum diameter D35 may range from about <NUM> to about <NUM>, or larger, with the other dimensions D1-D33 scaling up or down in proportion with D35.

A skilled person will understand that these dimensions are exemplary only, and the dimensions of the plumbing fitting and its features can be varied without departing from the scope of the invention.

Claim 1:
A plumbing fitting (<NUM>) comprising:
a cap (<NUM>); and
a body (<NUM>) comprising a fitting end (<NUM>) that is configured to be received by the cap (<NUM>), the body (<NUM>) comprising a first engagement projection (<NUM>) and a second engagement projection (<NUM>) that are circumferentially spaced apart from each other and that extend radially outwardly from an outer circumferential surface (<NUM>) of the fitting end (<NUM>);
wherein the cap (<NUM>) comprises:
a first tab (<NUM>) and a second tab (<NUM>), each tab having a free end (<NUM>, <NUM>) at a receiving end (<NUM>) of the cap (<NUM>);
the first tab (<NUM>) comprising a first receiver (<NUM>) that is configured to receive the first engagement projection (<NUM>) and the second tab (<NUM>) comprising a second receiver (<NUM>) that is configured to receive the second engagement projection (<NUM>);
wherein the tabs (<NUM>, <NUM>) are configured to permit flexure of each tab relative to the other; and
wherein each tab (<NUM>, <NUM>) comprises a radially inwardly extending spacer member (<NUM>, <NUM>) at the free end (<NUM>, <NUM>) of the tab (<NUM>, <NUM>);
wherein the spacer members (<NUM>, <NUM>) are configured such that, as the fitting end (<NUM>) is received by the cap (<NUM>), the free end (<NUM>, <NUM>) of each of the tabs (<NUM>, <NUM>) is displaced radially outwardly so as to space apart an inner circumferential surface (<NUM>) of the tabs (<NUM>, <NUM>) from the outer circumferential surface (<NUM>) of the fitting end (<NUM>), thereby providing clearance for receipt of the engagement projections (<NUM>, <NUM>) by the receivers (<NUM>, <NUM>).