GB2264761A

GB2264761A - Integral pipe coupling with reflex pipe end

Info

Publication number: GB2264761A
Application number: GB9203989A
Authority: GB
Inventors: Ronald Pardy
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1992-02-25
Filing date: 1992-02-25
Publication date: 1993-09-08
Also published as: GB9203989D0

Abstract

A quick-fit push-on coupling particularly suitable for the automotive industry is made integral with a pipeline (6) of nylon or other suitable plastics material. The coupling has a reflex end (8) which latches onto a ring (3) of a co-operating member (1) to which the coupling is attached. The reflex end (8) may lie outside the pipeline (6) or within an enlarged facetted section (7) of the pipe. The coupling is by forming a blow moulding process. The pipeline is heated and blown into a mould. The enlarged section is severed from the pipeline and the end is folded back on either internally or externally to form a reflex end (8). The coupling may be sealed on the co-operating member with the aid of a Neoprene ring (4). The coupling may be removed with the aid of a tool which lifts the reflex end (8) from engagement with the ring (3). <IMAGE>

Description

Title: Pipe coupling and methods of forming them Field of the invention The invention relates to pipe couplings and to a method of forming pipe couplings. The invention particularly relates to means of providing a female coupling on a plastics pipe to be attached to a male member. The invention provides a push-fit quick-coupling for vent lines, vacuum lines, air lines, and other pipe lines, possibly even fuel lines, as used in the automobile industry. The coupling may be adapted for a pull-off release or for release with the aid of an uncoupling key for situations or applications in which a tight coupling is required and in which the release forces are therefore higher by design.

Background to the invention Extruded plastics pipeline, generally nylon pipeline, is used extensively in the automobile industry. Connecting such pipelines to units and to each other can be relatively expensive and time consuming for assembling and removal.

Generally known couplings require assembly and fixing to the pipeline before the line is coupled to another member or another pipeline.

The present invention seeks to provide a female coupling which is integral with the pipeline and formed thereon.

Summary of the invention According to the present invention there is provided, for a co-operating coupling member, a pipe hose coupling integral with a pipeline and comprising a reflex end of the pipe overlapping an end section of the pipe, said reflex end of the pipe acting as a latching member to retain the coupling in position on the co-operating coupling member.

The reflex end of the pipe may be outside, but preferably, inside an enlarged end section of the pipe. The enlarged end section may be of circular, oval or multi-facetted cross section. The enlarged end section may gradually taper to the dimensions of the pipeline, or it may be provided with tapered shoulders. The reflex end of the pipe is preferably continuous although it may be partially or completely divided by slits to form reflex fingers.

A sealing ring, such as a nitrile rubber sealing ring, may be located within the enlarged end of the pipe and dimensioned so that it fills the gap between the enlarged end section and the male coupling member on which the pipe coupling fits. The sealing ring butts up against the ring on the male member which holds the ring against any pressure build-up in the pipeline.

When the reflex end of the pipe lies outside the end section of the pipe the end section need not be enlarged and the bore of the pipeline can be dimensioned to be a push-fit onto the male member. In such cases the coupling may be held in place by a cap, detent mechanism or other form of latching which co-operates with the reflex end of the pipe.

According to a second aspect of the invention there is provided a method of forming a pipe coupling which is integral with a pipeline comprising of the steps of blow moulding a section of pipe within a mould so as to enlarge a section of the pipe, severing one end of the enlarged section from the adjacent pipeline, wrapping said end back on the adjacent section of pipe so that it lies either within or outside the end of the pipe to form a reflex end of the pipe which acts as a latching rim so that in use it locates with a coupling member having a co-operating latching means.

The severing of the enlarged section may be adjacent to the pipeline or at the remote end of the enlarged section depending whether the reflex end of the pipe is to be internally reflexed or externally reflexed. Preferably the reflex end lies within the enlarged section. The mould may be facetted with six or eight sides so that the crease lines in the enlarged section of blown pipeline act as structural strengthening for the coupling.

Descríption of the drawings The invention will now be described, by way of example, with reference to the accompanying diagrammatic drawings in which:- Figures 1 - 3 illustrate stages in the manufacture of a pipe coupling; Figure 4 shows cross sections through the pipe coupling; Figure 5 shows a pipe coupling mounted on a male coupling member; Figure 6 shows a first alternative form of pipe coupling; Figure 7 shows a second alternative form of pipe coupling; and Figure 8 shows a pipe coupling and removal tool for releasing the pipe coupling from a male coupling member.

Specific Description Referring now to the drawing, a pipe coupling according to the invention is made by: placing a nylon pipe shown in figure 1 in a two part mould; heating the pipeline within the mould until it is plastic, and with the aid of a pressure line coupled to the pipeline expanding the pipeline within the mould, as shown in figure 2; reducing the applied pressure and heat; splitting the two part mould; removing the moulded pipeline; and, severing the moulded section from one end of the pipeline, as shown in figure 3.

The expanded section is severed about the line X-X for an internal reflex end, or about the line Y-Y for an external reflex end.

The severed end of the pipeline is then trimmed and whilst it is still warm and plastic the end is folded back on itself to form a reflex end lying outside the non-expanded end section, or preferably inside the expanded section of the pipe The reflex end is folded relative to the adjacent end section of the pipe to form an acute angle therewith.

Before the end is folded it may be slit into fingers to facilitate the folding process.

As shown in figure 3 the expanded section is faceted with six sides. Figure 3 also shows a cross section 'A' through the coupling at the line a-a , and a cross section 'B' through the coupling at the line b-b . The mould is sixsided and the facets gradually taper to the circular section of the normal pipe section so that structural strength is retained in the coupling.

The pipe coupling may now be coupled to a co-operating male member as shown in figure 5. The co-operating member consists of a stem 1 projecting from a unit 2. The stem 1 has a retaining ring 3. A nitrile rubber sealing ring 4 may be located against a side wall of the ring 3 and dimensioned so that it forms a tight sliding seal against the inside of the pipeline. The sealing ring is trapped between the side wall of the ring 3 and a shoulder 5 formed by the part of the pipe linking the normal section of the pipe with the expanded section, as shown in figure 5. The male and female couplings together form a fluid tight joint between the pipeline and the unit 2. The coupling is held on the stem 1 as the reflex end latches onto the ring 3.

The female coupling as shown in figure 5, is integral with a pipeline 6 and consists of an expanded section 7 united to the pipeline 6 by the shoulder 5, and coupled to a reflex end 8 lying inside the section 7. As previously described the severed end of the expanded section 7 is folded back into the expanded section to form the reflex end 8.

In use the pipeline and coupling are pushed over the stem 1 until the reflex end 8 drops over the ring 3 and latches into place against the side wall of the ring 3. The reflex end 8 acts in a similar manner to a fishing hook barb to restrain removal of the coupling.

The reflex section of the coupling may be formed outside the pipe to form a coupling as shown in figure 6. Referring now to figure 6 the reflex end 9 is now arranged to co-operate with a detent mechanism or a locking cap 10 which may be clipped or screwed onto retaining annulus 11 projecting from the unit 2. A ramp 12 or a tube (not shown) which fits inside the end of the pipeline supports the coupling and holds it in position in use.

To release this form of coupling the cap 10 is unscrewed or unclipped from the annulus 11 which allows the pipeline to be slid off the tube or withdrawn from the ramp 12.

An alternative form of release is shown in figure 7. As can be seen from the cross section view about the line Z-Z of figure 7 the coupling has been formed in an oval mould.

However the stem 1 and ring 3 are right circular cylindrical as in figure 4. This coupling may be released by squeezing the oval section of the coupling into a substantially circular shape until the reflex end of the coupling releases from the ring 3.

If the nylon pipeline is of thin section and the form of coupling is as shown in figure 4, it is possible to pull the coupling apart. However if the reflex end is stiff a tool is required to release the coupling. Referring now to figure 8 this shows a coupling as shown in figure 4 with a release tool 13 comprising a plate 14 mounted on a saddle 1.5 which fits under the reflex end 8 to release it by a rocking motion from the ring 3. The pipeline 6 is pulled to release the coupling as the tool 13 is rocked under and around the reflex end 8.

It will be appreciated that any suitable plastics material may be used for the pipeline provided that it is suitable for blow moulding or a similar moulding process. The invention is particularly useful in the automobile industry for quick-fit couplings simple to form with minimum components. Because the coupling is formed integral with the pipeline the risk of leakage at the coupling is considerably reduced. The 0-ring seal also assists in leakage reduction.

If necessary the 0-ring seal may be held in place between two rings on the stem.

The invention provides a high 'pull-out' resistance suitable for vent lines, vacuum lines, air lines, and possibly fuel lines. The coupling has low production cost and is suitable for fast assembly. If low 'pull-off' loads are acceptable the reflex end can be sprung off and the reflex end reinserted for re-assembly.

Claims

Claims:

1. A pipe hose coupling integral with a pipeline, for coupling to a co-operating member, and comprising a reflex end of the pipe overlapping an end section of the pipe, said reflex end of the pipe acting as a latching member to retain the pipe hose coupling in position on the co-operating coupling member.

2. A pipe hose coupling as claimed in claim 1 in which the reflex end lies inside an enlarged end section of the pipe.

3. A pipe hose coupling as claimed in claim 2 in which the enlarged end section has a multi-facetted cross-section.

4. A pipe hose coupling as claimed in any preceding claim in which a sealing ring is located between the coupling and the co-operating member.

5. A pipe hose coupling as claimed in claim 4 in which the sealing ring is located a side wall of a ring on the cooperating member, the other side wall of which reacts with the end of the reflex end of the pipe to latch it in position on the co-operating member.

6. A pipe hose coupling as claimed in any preceding claim in which the reflex end is divided by slits to form fingers.

7. A method of forming a pipe coupling as claimed in any preceding claim, which pipe coupling is integral with a pipeline comprising of the steps of blow moulding a section of pipe within a mould so as to enlarge a section of the pipe, severing one end of the enlarged section from the adjacent pipeline, wrapping said end back on the adjacent section of pipe so that it lies either within or outside the end of the pipe to form a reflex end of the pipe which acts as a latching rim so that in use it locates with a coupling member having a co-operating latching means.

8. A method of forming a pipe coupling as claimed in claim 7 in which the enlarged section is severed from the pipeline adjacent to the pipeline and the reflex end is folded back on the pipeline external to the pipeline.

9. A method of forming a pipe coupling as claimed in claim 7 in which the enlarged section is severed from the pipeline at the remote end of the enlarged section from the pipeline and the reflex end is folded within the enlarged section.

10. A method forming a pipe coupling as claimed in any of claims 7 to 9 in which the mould has facets which taper to the pipeline.

11. A method of forming a pipe coupling s claimed in any of claims 7 to 10 in which the pipeline material is nylon.

12. A method of forming a pipe coupling as claimed in any of claims 7 to 11 in which the reflex end is slit to form fingers.

13. A pipeline coupling substantially as hereinbefore described with reference to the drawings.

14. A method of forming a pipeline coupling substantially as hereinbefore described.