GB2263956A

GB2263956A - A push-on pipe joint

Info

Publication number: GB2263956A
Application number: GB9202359A
Authority: GB
Inventors: David Thomas Bowles
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1992-02-04
Filing date: 1992-02-04
Publication date: 1993-08-11
Also published as: GB9202359D0

Abstract

A fluid tight push-on joint between a hose 10 and a tubular spigot 12 requires the presence of holes 14 through the hose wall which will assist the tube to relax behind a bead 16, and which can also be located over a retaining lug 18, the end of an integral hooked member (120), Figure 3, or a further bead (216a), Figure 5. <IMAGE>

Description

A PUSH-ON PIPE JOINT This invention relates to a push-on pipe joint for connecting a hose to a tubular spigot. Such joints are used in a number of places in automobile assembly, particularly for connecting flexible pipes to relatively rigid spigots in and around the fuel tank system.

According to the present invention, there is provided a fluid tight push-on joint in which a hose has been pushed onto a tubular spigot which has a raised annular bead around its open end, wherein the hose has an internal cross sectional dimension smaller than the outer cross-sectional dimension of the annular bead so that an interference occurs between the hose and the bead to form a seal, and wherein the hose also has an aperture through the hose wall close to the end thereof and lying beyond the bead when the hose is fitted on the spigot.

The provision of an aperture through the hose wall allows the hose to relax behind the annular bead which produces a positive retention of the hose on the bead.

The bead preferably has a sharp outer periphery, so that the seal between the spigot and the hose is formed by annular line contact between the two parts. Preferably the annular bead is shaped, in cross section, like a barb to assist push-on of the hose and to hinder pull-off of the hose.

There may be more than one annular bead, with the or each further bead being arranged axially behind the first annular bead.

In a preferred embodiment, the hose has two apertures through the hose wall.

The spigot may have an external tooth or teeth which engage through the or each aperture in the hose wall to provide a second positive retention mechanism of the hose on the spigot.

The invention also provides a spigot and a hose which can be assembled to form a joint as set forth above.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross section through a first embodiment of a joint in accordance with the invention; Figure 2 is a perspective view showing the joint of Figure 1 prior to assembly; Figure 3 shows a cross section through a second embodiment of joint in accordance with the invention; Figure 4 is a perspective view of the joint of Figure 3, prior to assembly; Figure 5 is a cross section view through a third embodiment of joint in accordance with the invention; and Figure 6 is a perspective view of the joint of Figure 5 prior to assembly.

Figures 1 and 2 show a hose 10 and a spigot 12. The hose has apertures 14 through the hose wall. The spigot 12 has an annular bead 16 and, two opposite external teeth iS, the positions of which register with the positions of the holes 14.

In use, the hose 10 is pushed onto the open end of the spigot so that the hose wall expands as shown in Figure 1 over the bead 16 to form a seal between the inner wall of the hose and the outer lip of the bead 16. The bead is constructed with a triangular configuration with an inclined front wall facing the direction of push-on loads and a vertical rear wall facing the direction of pull-off loads.

This configuration of the barb assists assembly of the joint and resists separation of the two parts.

The main function of the holes 14 is to allow the hose wall (which has to yield to pass over the bead 16) to relax when it has passes the bead. The hose wall will therefore take up a stable configuration in which the internal hose diameter is smaller than the external diameter of the bead, so that pull-off of the hose is difficult.

As a backup measure, the holes 14 also locate over the teeth 18 to provide a secondary retention mechanism.

In Figures 3 and 4, the spigot 112 has a single bead 116 and a pair of opposite retention clips 118. The retention clips have fingers 120 which engage from outside through the apertures 14 in the hose 10 to act as a secondary obstacle to pull-off loads. The fingers 20 can however be lifted out of the apertures 14 when the joint is to he disassembled.

In Figures 5 and 6, the spigot 212 has three beads 216 arranged in series, and Figure 5 shows how the apertures 14 relax over the innermost bead 216a to retain the hose 10.

The components of this. joint are easy to construct and the joint itself is easy to assemble. High pull-off loads can be achieved.

In the first and second embodiments shown in Figures 1-4, rotation of the hose 10 on the spigot 12, 112 is positively prevented. In the third embodiment shown in Figures 5 and 6, rotation will be hindered. Furthermore, where rotation is prevented, the assembly orientation is also controlled.

Particularly in the first and second embodiments set out above, a quick visual inspection of the joint will reveal whether the joint has been correctly made or not.

The invention is particularly suitable for use in connecting a nylon hose to a spigot made of high density polyethylene which can for example be welded to the wall of a motor vehicle fuel tank.

Claims

1. A fluid tight push-on joint in which a hose has been pushed onto a tubular spigot which has a raised annular bead around its open end, wherein the hose has an internal cross sectional dimension smaller than the outer cross-sectional dimension of the annular bead so that an interference occurs between the hose and the bead to form a seal, and wherein the hose also has an aperture through the hose wall close to the end thereof and lying beyond the bead when the hose is fitted on the spigot.

2. A joint as claimed in Claim 1, wherein the bead has a sharp outer periphery, so that the seal between the spigot and the hose is formed by annular line contact between the two parts.

3. A joint as claimed in Claim 1 or Claim 2, wherein the annular bead is shaped, in cross section, like a barb to assist push-on of the hose and to hinder pull-off of the hose.

4. A joint as claimed in any preceding claim, wherein more than one annular bead is provided, with the or each further bead being arranged axially behind the first annular bead.

5. A joint as claimed in any preceding claim, wherein the hose has two apertures through the hose wall.

6. A joint as claimed in any preceding claim, wherein the spigot has an external tooth or teeth which engage through the or each aperture in the hose wall to provide a second positive retention mechanism of the hose on the spigot.

7. The combination of a hose and a spigot adapted to be assembled to form a joint as claimed in any preceding claim.

8. A hose having two holes through the hose wall.

9. A joint substantially as herein described, with reference to any one embodiment shown in the accompanying drawings.