AU2003200545B1 - Pipe coupling nut including recessed ribs - Google Patents

Description

11692AU

ORIGINAL

Complete Specification Applicant: Philmac Pty Ltd Title: A pipe coupling nut including recessed ribs Address for Service: LESICAR PERRIN, 49 Wright Street, Adelaide, South Australia 5000, Australia The following statement is a full description of this invention, including the best method of performing it known to me/us: A pipe coupling nut including recessed ribs The present invention relates to a pipe coupling nut and in particular to a pipe coupling nut having recessed ribs thereby reducing the overall diameter of the nut.

BACKGROUND OF THE INVENTION Pipe couplings are well known and have been used, especially in the water reticulation industry, for a number of years. For example, the present applicant is the owner of a number of patents dealing with pipe couplings that are able to couple several water pipes under mains pressure. For a background discussion of such couplings the reader is referred to International Patent Applications PCT/AU94/00406 and PCT/AU01/01665.

In brief these couplings generally include a sub-assembly of a compression sleeve, a resilient gasket ring attached to the inner end of the compression sleeve, a gripping member, and a nut. The gasket ring encounters an abutment in a socket in the body as the nut is tightened, and further tightening of the nut radially compresses the gripping member so that its inwardly directed barbed projections engage the outer surface of a pipe to which the coupling is attached. The end of the pipe is freely insertable through the gripping member and sleeve and into the socket in the body.

There are also provided abutment surfaces within the body coupling and the nut that abut inner and outer surfaces of a flange outstanding from the outer end of the compression sleeve.

Thus the reader would now appreciate that a good seal is achieved by providing sufficient torque on the nut that causes the grip ring to effectively engage the pipe and the gasket ring. To assist in providing a good grip, especially when the tightening of the nut is achieved by hand, the nut outer surface typically includes ribs that extend in the longitudinal direction of the nut and assist in the user gripping the nut.

One of the difficulties in this type of arrangement is that the protruding ribs increase the overall effective diameter of the nut and thus the whole pipe coupling.

Whilst in most cases this is not an issue, it is undesirable in areas where space is at a premium, especially when being used in commercial and private dwellings where the couplings are typically found in wall cavities.

2 A further issue in such couplings is that the addition of the ribs results in more material needed to construct a nut. Although the amount of material may not be great, when such nuts are moulded in runs of hundreds of thousands, a few percent of extra material equates to significant quantities indeed.

It is an object of the present invention to overcome at least some of the aforementioned problems or provide the public with a useful alternative.

It is a further object of the present invention to provide a pipe coupling nut that includes ribs to assist in gripping of the nut for rotational movement thereof, but where the overall diameter of the nut is not increased.

SUMMARY OF THE INVENTION Therefore in one form of the invention there is proposed a nut for use in a pipe coupling, said pipe coupling including a hollow body having external threads, said nut including: a longitudinal body including inner threads adapted to engage said hollow body external threads; an outside surface generally parallel to the rotational center line of said nut; a plurality of circumferentially spaced apart axial recesses in said outside surface; each said recess including a central projecting rib parallel to said recess.

In preference, the ribs slightly protrude beyond the outer surface. However it is to be understood that they may equally well be wholly contained within each recess.

Preferably said nut includes said inner threads at one end thereof.

Preferably said nut outer surface converges towards the nut center line at the other end thereof. This defines an aperture through which is inserted a pipe that is to be coupled.

Preferably said recesses extend only along the non-converging nut outer surface. This is where a suitable tool may engage the ribs.

In preference, said ribs extend further along the converging outer surface where there are no recesses.

Preferably said recesses are of an arcuate shape.

In preference said ribs are of a rectangular cross-sectional shape to enable them to be engaged by a tool.

In a further form of the invention there is proposed a coupling for connection of a polymeric pipe, said coupling including; a hollow body having an external thread extending at least in part therealong and having an inner surface; a nut threadably engaging said body external threads, said nut having at one end an internal thread co-operable with said body external thread, said nut further having an outside surface generally parallel to the rotational center line of said nut, a plurality of circumferentially spaced apart axial recesses in said outside surface whereby each said recess includes a central projecting rib parallel to said recess, said nut further including an inwardly diverging inner surface; a deformable gripping member having a first surface generally parallel to said body inner surface and having a second outwardly converging outer surface extending from said first surface, said member including radially inward barbs; wherein upon tightening of said nut, said nut inner surface abuts against and exerts a force on said gripping members second surface both in the longitudinal and radial directions to thereby cause the grip ring to be urged both radially and longitudinally into the body, said nut inner surface sliding alongside said body first surface; whereby said nut ribs assist in the gripping of said nut for tightening thereof.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several implementations of the invention and, together with the description, serve to explain the advantages and principles of the invention.

In the drawings, Figure 1 is a perspective exploded view of a pipe coupling with a nut embodying the present invention; Figure 2 is a perspective view of a nut according to the present invention; Figure 3 is a side view of the nut of Figure 2; Figure 4 is an underside perspective view of the nut of Figure 2; Figure 5 is a perspective view of a tool that may be used to operate a nut embodying the present invention; Figure 6 is a side view of the tool of Figure 5 when used on a nut the subject of the present invention; and Figure 7 is a perspective view of the nut and tool of Figure 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The following detailed description of the invention refers to the accompanying drawings. Although the description includes exemplary embodiments, other embodiments are possible, and changes may be made to the embodiments described without departing from the spirit and scope of the invention. Wherever possible, the same reference numbers will be used throughout the drawings and the following description to refer to the same and like parts.

Referring now to the Figures and specifically to Figure 1 there is shown a pipe coupling 10 with a pipe 12 to be inserted into the coupling 10. The coupling includes a nut 14, a gripping member or grip-ring 16, seal 18 and a body 20. The grip-ring includes splits 22 since it must be radially and thereby circumferentially deformable, and is typically a split ring or collet for ease of manufacture. The gripring 16 further includes radially inwardly and axially spaced barb projections 24. The splits 22 enable the grip ring 16 to be radially compressed so that the barbs 24 engage the pipe 12.

The nut 14 includes female threads 26 that engage corresponding male threads 28 on the body 20. In use, pipe 12 is inserted though the aperture 30 of the nut 14 and through the bore 32 of the grip-ring 16. The nut 14 is then rotated in the appropriate and typically clockwise direction to drive the nut 14 onto the body 20 and the grip ring 16. The nut 14 includes an inwardly diverging surface 34 that abuts against the grip ring outwardly converging surface 36. As the nut 14 is tightened it thus causes both a radial and a longitudinal force on the grip ring 16 that in turn passes that force through barbs 24 to lock onto pipe 12.

Nut 14 includes a plurality of circumferentially spaced apart axial recesses 38, each recess 38 including a central projecting rib 40 parallel to said recess, the ribs joining at the end of said nut 14 to a circumferential lip 42. The recesses 38 typically extend along the nut outer surface 44 that is parallel to the center of rotation of the nut 46.

The skilled addressee should now appreciate the significant advantage of a nut as provided by the present invention. The ribs 40 enable a user to grip the nut 14, whether by hand or by a tool as discussed below, even though the ribs 40 may protrude only fractionally beyond the outer surface 44 of the nut 14. This results in a nut whose overall outer diameter is less than a conventional nut but that is adapted for connection of same diameter pipes. Furthermore, the use of the recesses 38 reduces the total amount of material used in the production of a nut 14 according to the present invention thereby saving on material. Although the savings per individual nut may not be great, the savings are considerable when one is moulding hundreds of thousands of such nuts The nut 14 further includes an outwardly converging outer surface 47, ribs extending along this surface as well, but not the recesses 38, the ribs 40 then joining in a second circumferential lip 48 on the other side of the nut The nut 14 is shown in more detail in Figures 2-4 illustrating the relative dimensions, by way of example, of the individual nut features.

It is to be understood that the interior design of the nut 14 may be changed to accommodate particular pipe couplings and may include features besides the internal threads 26. It is not the intention of the present invention to limit the internal configuration of the nut, the main thrust of the invention being the configuration of the recesses and ribs within said recesses.

To assist in rotation of the nut 14, typically to tighten the nut, there is provided a tool 50, as shown in Figures 5, 6, and 7, Figure 5 illustrating the tool 50, Figures 6 and 7 the tool when engaging a nut 14 embodying the present invention. The tool includes a handle 52 for gripping by a user. A circular arm 54 extends from the handle 52 and includes a notch 56 shaped to engage the rib 40 of the nut 14. The arm 54 includes sections of different radii including a first section 58 and a second section the radii adapted for engagement of different diameter nuts. An abutment shoulder 62 engages rib 40 to assist in engaging the nut 14. The notch 56 also includes an outer shoulder 64 to engage the rib. The outer shoulder can also be fluted to present a larger cross-sectional surface at the point of contact with the rib.

To assist in a good connection between the tool 50 and the nut 14, the ribs may include sharp edges 66. However, the skilled addresses would appreciate that the edges 66 may not be sharp depending in part on the tooling and on a microscopic level may indeed be rounded or of an arcuate shape. However, it is obviously desirable for the ribs to have sharp or at least acute edges 66 that can be gripped by the tool It is also to be understood that although the above example showed the ribs protruding beyond the upper surface of the recesses, the ribs 40 may very well be wholly contained within the recesses 38. This will depend in part on the total number of recesses around the nut. For example, if one were to use a tool than there may be as few as three recesses disposed symmetrically and circumferentially around the nut with three corresponding ribs.

It should now be apparent to the reader that the nut embodying the present invention still enables a user to engage the nut with sufficient grip to be able to rotationally tighten the nut whether by a hand or by a tool whist being of a more compact configuration and one that requires less material. This is of a significant commercial advantage especially when pipe couplings such as the one described earlier are used in small spaces, such as the supply of water in domestic and commercial applications and where space is at a premium.

The nut as well as the rest of the pipe coupling is made from well known thermoplastic materials such as acetic plastics material or polypropylene.

Further advantages and improvements may very well be made to the present invention without deviating from its scope. Although the invention has been shown and described in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope and spirit of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

In any claims that follow and in the summary of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprising" is used in the sense of "including", i.e. the features specified may be associated with further features in various embodiments of the invention.

Dated this Tuesday, February 18, 2003 Philmac Pty Ltd By their Patent Attorneys LESICAR PERRIN

Claims (9)

1. A nut for use in a pipe coupling, said pipe coupling including a hollow body having external threads, said nut including: a longitudinal body including inner threads adapted to engage said hollow body external threads; an outside surface generally parallel to the rotational center line of said nut; a plurality of circumferentially spaced apart axial recesses in said outside surface; each said recess including a central projecting rib parallel to said recess.

2. A nut as in claim 1 wherein said ribs protrude beyond said outer surface.

3. A nut as in claim 1 or claim 2 wherein said nut includes said inner threads at one end thereof.

4. A nut as in any one of the above claims wherein said nut outer surface converges towards the nut center line at the other end thereof.

5. A nut as in claim 4 wherein said recesses extend along said non-converging outer surface only.

6. A nut as in claim 4 wherein said ribs extend further along said converging outer surface.

7. A nut as in any one of the above claims wherein said recesses are of an arcuate shape.

8. A nut as in any one of the above claims wherein said ribs are of a rectangular cross-sectional shape.

9. A pipe coupling for connection of a polymeric pipe, said coupling including; a hollow body having an external thread extending at least in part theralong and having an inner surface; a nut threadably engaging said body external threads, said nut having at one end an internal thread co-operable with said body external thread, said nut further having an outside surface generally parallel to the rotational center line of said nut, a plurality of circumferentially spaced apart axial recesses in said outside surface whereby each said recess including a central projecting rib parallel to said recess, said nut further including an inwardly diverging inner surface; a deformable gripping member having a first surface generally parallel to said body inner surface and having a second outwardly converging outer surface extending from said first surface, said member including radially inward barbs; wherein upon tightening of said nut, said nut inner surface abuts against and exerts a force on said gripping members second surface both in the longitudinal and radial directions to thereby cause the grip ring to be urged both radially and longitudinally into the body, said nut inner surface sliding alongside said body first surface; whereby said nut ribs assist in the gripping of said nut for tightening thereof.