NZ531121A

NZ531121A - Push-in pipe connector with pretension spring between collar-and-fingers component and connector

Info

Publication number: NZ531121A
Application number: NZ531121A
Authority: NZ
Inventors: Michael White
Original assignee: Mm Kembla New Zealand Ltd
Priority date: 2004-02-12
Filing date: 2004-02-12
Publication date: 2004-10-29
Also published as: WO2005078328A1; AU2004202646A1; AU2004202646B2

Abstract

A pretension spring is located between the ring 4 of a collar-and-fingers component and the adjacent end of the connector body 1. A number of advantages are noted including assisting in gripping of an inserted pipe end p.

Description

<div class="application article clearfix" id="description"> 531121, NEW ZEALAND PATENTS ACT, 1953 COMPLETE SPECIFICATION A PUSH-IN PIPE CONNECTOR We, M M KEMBLA NEW ZEALAND LIMITED, a New Zealand company of 21 Sir William Avenue, East Tamaki, Auckland, New Zealand, do hereby declare this invention to be described in the following statement: -1 - intellectual property OFFICE OF N.7. 1 b JUN 2004 -2- FIELD OF INVENTION The invention relates to push-in type connectors as are typically used for connecting pipe such as copper pipe in plumbing for example, and into which in use the pipe end or ends may generally simply be pushed to form a secure water or airtight connection. BACKGROUND OF INVENTION With a push-in type pipe connector a pipe end or ends may simply be pushed into the connector to connect the pipe end to the connector. It may be necessary to first clean any swarf for example from the cut end of a metal pipe, but with a push-in connector it is not necessary to for example screw tighten a lock ring or similar after the pipe has been inserted in the connector to clamp the pipe end to the connector. Various types of push-in pipe connector are described in US patents 5,005,883 and 4,178,023, Australian patents 574530, 594180, 620853, 626617, 670450 and equivalent patents in other countries, and subsequent patents and published patent applications to John Guest or John Guest Engineering Limited disclose various forms of push-in pipe connector. Push-in pipe connectors are also sold by Hepworth Building Products Limited. SUMMARY OF INVENTION It is an object of the invention to provide an improved or at least alternative push-in pipe connector. In broad terms in one aspect the invention comprises a push-in pipe connector including: a hollow connector body including at least one an open end into which a pipe end can be inserted to connect the pipe; a collar-and-fingers component including a ring portion surrounding said open end of the connector body and a number of fingers extending within the connector body from the intellectual property office of n.z. 16 JUN 2004 received -3 - ring portion and each terminating in a gripping edge for engaging the outer wall of a pipe end inserted into the connector body; a pre-tension spring device captured between the ring portion of the collar-and-fingers component and the end of the connector body which biases the collar-and-fingers component away from the connector body. Preferably the pre-tension spring device comprises a spring washer. Preferably the collar-and-fmgers component is formed from a spring steel. Preferably the connector body has been formed from metal tube by mechanically deforming the metal tube, and most preferably the connector body is formed from copper. Most preferably pipe connector has a "low profile". The widest diameter of the exterior of the connector body may be not more than 140%, or more preferably 130%, of the outer diameter of the widest diameter pipe with which the connector may be used. BRIEF DESCRIPTION OF THE FIGURES The invention is further described with reference to the accompanying drawings which show a preferred embodiment pipe connector of the invention by way of example and without intending to be limiting. In the drawings: Figure 1 is a perspective view of the preferred form pipe connector; Figure 2 is a view of the pipe connector with the body of the pipe connector cut away on one side; Figure 3 is a view of the pipe connector similar to Figure 2 but with pipes inserted into the pipe connector on either side and again with the body of the pipe connector cut away on one side; and Figure 4 shows a preferred form collar-and-fmgers component and associated spring washer before fitting of the collar-and-fingers component to the pipe connector. -4- DETAILED DESCRIPTION OF PREFERRED FORMS Referring to Figures 1 to 3 the preferred form connector comprises a connector body 1 shaped generally as shown and which in the preferred form has a "low profile" relative to the pipe diameter as will be further described, and is which most preferably formed from metal such as copper particularly when intended for connecting copper pipe. Alternatively however the connector body may be formed from any other suitable material such as a plastics material for example. The connector body 1 has a hollow interior and is open at either end, and includes a collar-and-fingers component 3 at either end including a ring portion 4 and a number of fingers 5 which extend from the ring portion into the interior of the connector body as shown. In the preferred form at least the fingers 5 are formed from a spring metal and preferably the whole of the collar-and-fmgers component is formed from a spring metal such as spring stainless steel. The fingers 5 of the collar-and-fingers component terminate in a gripping edge 6. The body of the connector has a shape which tapers internally with a reducing diameter towards the open end of the body of the connector on either side of the connector at 1 a as shown (see Figures 2 and 3), so that once the fingers of the collar-and-fingers component have been inserted into the body of the connector, it is relatively difficult (although not impossible) to separate the collar-and-fingers component from the connector body. A spring washer 7 is the captive between the collar-and-fingers component and the connector body at either end of the connector as shown. In use, when a pipe end is inserted and into the open end of the connector body and through the collar-and-fingers component, the pipe end can be pushed fully home to the position of the pipe end shown in Figure 3. In the preferred form an internal, circumferential ridge is formed in the centre section of the connector body as shown, which provides an internal annular stop within the interior of the connector body. This acts as a stop against which the end of the pipe abuts when the pipe end has been pushed fully home within the connector body, and provides a clear indication to the installer that the pipe has been inserted fully into the fitting. \ 6 J'JH 2004 * * c i M E D Preferably the internal height of the annular ridge 10 forming the stop is approximately the same as the typical wall thickness of the pipe with which the connector will be used, which assists in minimising flow turbulence through the fitting as fluid passes between the two connected pipes, which would otherwise be generated by sudden changes in internal diameter of the fluid flow path. Preferably also the end stop is provided centrally between the two ends of the fitting (in the case of a pipe to pipe connector as shown). As the pipe end is moved forwardly as it is pushed home into the connection, the gripping edges 6 of the fingers drag over the pipe end, and the collar-and-fingers component 5 may tend to move forward slightly against spring washer 7. However, after insertion of the pipe end any rearward movement of the pipe (without first depressing the collar-and-fmgers component as will be described) relative to the connector body is inhibited. The gripping edges 6 of the fingers of the collar-and-fingers component bite into the exterior of the pipe so that any rearward movement of the pipe will also tend to move the collar-and-fingers component rearwardly, which in turn causes the fingers to be compressed harder against the pipe end by the engagement of the of the fingers 5 against the interior surface of the tapered part 1 a of the connector body. However to enable the pipe end to be intentionally separated from the connector, the ring portion 4 of the collar-and-fingers component may be manually or with a tool pushed back toward the connector body manually, in the direction of the arrow in Figure 5, compressing the pretension washer 7, which releases the fingers 5 and enables the pipe end to be withdrawn. In the preferred form the collar-and-fingers component including the fingers are formed from a spring metal and in particular spring stainless steel. In additional the fingers are shaped as shown each including a portion 5a which is cranked outwardly, and the ends 6 which are bent inwardly to engage the pipe. The collar-and-fingers component is separately shown in Figure 4. Preferably the ends 6 of the fingers are angled so that they do not engage the pipe perpendicularly but at a slight angle to the pipe as shown, which assists to ensure that as the pipe is moved rearwardly the fingers will reliably bite into the exterior of the pipe. Any number of fingers may be provided but typically there will be four to eight fingers spaced circumferentially around the collar-and-fmgers component. Preferably also the edges of the ends 6 of the fingers which contact outer surface of the pipe are radiused to have a concave edge profile which matches the outside diameter of the pipe, so that the gripping edge 6 of each finger contacts the outside surface of the pipe over the full length of the edge. intellectual property office of n.z. 1 6 JUN 2004 received The collar-and-fmgers component should be formed, and the material chosen to form the collar-and-fingers component, so that in use the fingers will have a degree of stiffness and also memory, which enables the pipe end to be inserted into the pipe and ensures that the fingers bite into the pipe end, but also ensures that the fingers are not permanently bent towards the pipe, so that to enable intentional withdrawal of the pipe end when the collar-and-fingers component is pushed against the connector body depressing the pre-tension washer 7, the fingers will return outwardly to their original position and disengage from the pipe end, enabling the pipe end to be withdrawn from the connector. The material from which the collar-and-fingers component is formed should also have sufficient strength to resist angular forces on the tube that may deform the fingers and separate the connection. Where the collar-and-fingers component is formed from a spring metal such as spring stainless steel as shown then reliable coupling of the pipe end to the connector is not temperature dependent. That is, the "grip" of the connector and in particular collar-and-fingers component including fingers on the pipe does not reduce at temperatures towards 100°C in applications where the pipe carries hot water ie is a hot water pipe. The preferred form connector also includes pre-tension spring washers 7, which offers a number of advantages. It is not necessary to insert and remove a separate C-clip between the collar-and-fingers component and pipe end after insertion of the pipe to fix the pipe, or to enable intentional removal of the pipe. The pre-tension washers 7 because they apply a rearward tension on the collar-and-fingers components also assist in establishing a reliable grip between the collar-and-fingers component fingers and a pipe end automatically and immediately on insertion of pipe ends into the coupling. In the preferred form the spring washers have a corrugated or "wavy" shape around their circumference as shown. Alternatively other forms of spring washer such as a split washer might be used, or some other form of pre-tension spring device such as two thin washers with a compressible elastomeric material layer between them for example. Preferably to ensure a fluid-tight seal an o-ring 8 is provided within the interior of the connector body as shown, through which the pipe end passes as the pipe end is inserted into intellectual property office of n.z. 16 JUN 2004 received the connector body. In the preferred form a washer 9 is provided on either side of the o-ring 8, and the washers 9 may be formed from a plastics material by injection moulding for example and have a castellated form as shown, which makes the relatively thick washers 9 more flexible for insertion through the smaller diameter entry to the interior of the connector body during assembly of the connector. This also enables (although with some difficulty) removal and replacement of the o-ring if required, part way through the life of the connector by breaking of the joint, removal of the collar-and-fingers component, removal of one or both of the washers 9, and removal replacement of the o-ring followed by reassembly of the connector (and reconnection of the pipe and connector). In the preferred form the coupling body has a "low profile" relative to the pipe outer diameter as shown. That is, the outer diameter of the connector body at its widest point is not much more than the diameter of the pipe with which the connector is intended to be used. To achieve this the connector body is most preferably formed from metal tube mechanically deforming the metal tube, such as by pressing and/or swaging the connector body from metal tube. Where the connector is intended for use with copper plumbing pipe we prefer to form the connector body from copper tube also. Preferably the diameter of the coupling body at its widest point is no greater than 120% and is preferably no greater than 115% of the outer diameter of the pipe. The preferred form collar-and-fmgers component may be produced, by pressing from sheet metal such as spring steel for example. In a first pressing or punching operation a cone shape is pressed from the sheet metal. In a second operation the end of the cone is flattened to form a thimble shape. A hole is then formed in the flattened end of the pressing, and then the sides of the thimble are cut out in a final pressing operation, to form the individual fingers. This is simply one way of forming the spring steel collar-and-fingers component of the preferred form connector and is not intended to be limiting. In addition any one or more of the above pressing operations may be combined. The preferred form connector shown in the drawings and described above is intended for connecting one pipe end to another pipe end in an in-line configuration. Connectors of the invention may be formed in other configurations such as in an elbow configuration for INTELLECTUAL PROPER™ OFFICE OF N.Z. 1 6 JUN m received connecting two pipes at an angle such as a right angle for example, in a T configuration for connecting three pipe ends etc. Also a connector of the invention may be intended for connecting a pipe end to an appliance such as a pump or similar, or another plumbing fitting such as a filter or tap. In these latter examples the connector body may be an integral part of the appliance or plumbing fitting or may have a threaded back end opposite the collar-and-fingers component and entry end for the pipe of the fitting, by which the connector can be threaded into a threaded bore of the tap or other plumbing fitting or appliance, or may have a back end opposite the entry end of the fitting which is fixed or attached to the appliance by welding, soldering, brazing, pressing, or bonding for example. The foregoing describes the invention including a preferred form thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be incorporated within the scope hereof as defined in the accompanying claims. intellectual property office of n.z. 16 JUN 20M received </div>

Claims

<div class="application article clearfix printTableText" id="claims"> CLAIMS:

1. A push-in pipe connector including: a hollow connector body including at least one an open end into which a pipe end can be inserted to connect the pipe; a collar-and-fingers component including a ring portion surrounding said open end of the connector body and a number of fingers extending within the connector body from the ring portion and each terminating in a gripping edge for engaging the outer wall of a pipe end inserted into the connector body; a pre-tension spring device captured between the ring portion of the collar-and-fingers component and the end of the connector body which biases the collar-and-fingers component away from the connector body.

2. A pipe connector according to claim 1 wherein the pre-tension spring device comprises a spring washer.

3. A pipe connector according to claim 2 wherein the spring washer has a corrugated shape around it's circumference.

4. A pipe connector according to any one of claims 1 to 3 wherein the collar-and-fingers component is formed from a spring steel.

5. A pipe connector according to claim 4 wherein the collar-and-fingers component is formed from stainless steel.

6. A pipe connector according to any one of claims 1 to 5 wherein the ends of the fingers of the collar-and-fingers component opposite to the ring portion of the collar-and-fingers component are bent inwardly towards a central axis of the collar-and-fingers component and pipe connector.

7. A pipe connector according to claim 6 wherein the collar-and-fingers component has been formed by pressing from sheet metal. intellectual property office of n.z. H JUN 2004 received -10-

8. A pipe connector according to any one of claims 1 to 7 wherein the hollow connector body has an internal diameter which increases from at or near the open end of the connector body and wherein the diameter of the collar-and-fingers component including the fingers of the collar-and-fingers component increases from at or near the ring portion of the collar-and-fingers component towards the ends of the fingers.

9. A pipe connector according to any one of claims 1 to 8 including an o-ring within the interior of the connector body through which the pipe end passes as a pipe end is entered into the connector.

10. A pipe connector according to claim 9 wherein the o-ring is captive within the widest diameter part of the interior of the connector body and includes a washer on either side of the o-ring.

11. A pipe connector according to claim 10 wherein the washers are formed from a plastics material and have a castellated form.

12. A pipe connector according to any one of claims 1 to 11 wherein the connector body has been formed from metal tube by mechanically deforming the metal tube.

13. A pipe connector according to any one of claims 1 to 12 wherein the connector body is formed from copper.

14. A pipe connector according to any one of claims 1 to 13 wherein the widest diameter of the exterior of the connector body is not more than 120% of the outer diameter of the widest diameter pipe with which the connector may be used.

15. A pipe connector according to any one of claims 1 to 13 wherein the widest diameter of the exterior of the connector body is not more than 115% of the outer diameter of the widest diameter pipe with which the connector may be used. intellectual property office of n.z. 16 jun m received

16. A pipe connector according to any one of claims 1 to 15, for connecting one pipe end to another pipe end including a said open end into which a pipe can be inserted to connect the pipe, a collar-and-fingers component, and a pre-tension spring device at each of two or more ends of the connector body.

17. A push-in pipe connector substantially as herein described with reference to Figures 1 to 4 of the accompanying drawings. intellectual property i OFFICE OF NT 11> JUN 2004 received </div>