GB2332721A

GB2332721A - Extruded or blow-moulded member, e.g. pipe, with integral end connection

Info

Publication number: GB2332721A
Application number: GB9727284A
Authority: GB
Inventors: Frederic Renaud; Louc Renou
Original assignee: Draftex Industries Ltd
Current assignee: Laird Holdings Ltd
Priority date: 1997-12-24
Filing date: 1997-12-24
Publication date: 1999-06-30
Also published as: WO1999034143A1; GB9727284D0

Abstract

The pipe (4), e.g. corrugated (6) to render it at least partially flexible, has the integrally extruded connection (5) to enable it to be locked and sealed to a rigid tubular fixture (8) e.g. a pipe. The connection (5) is provided with a groove (20) locating an O-ring (38) for sealing purposes. The tubular fixture (8) has slots (36) for receiving a spring wire clip (40) which engages a surface (24) of the connection (5) to prevent its removal. Alternatively, the connection has a groove accepting the base of an axial tongue which enters into an axial slot of the fixture (8), with a shoulder to latch against an end surface of an aperture in the fixture to prevent removal.

Description

CONNECTION OF EXTRUDED OR MOULDED PARTS The invention relates to the connection of extruded or moulded (blow-moulded) parts - that is, to the connection of an extruded or blow-moulded part to another part which may or may not be an extruded or blow-moulded part. In an embodiment of the invention to be described in more detail below by way of example only, a part, such as a corrugated pipe part produced by blow-extrusion for use in a motor vehicle, is connected to another part.

According to the invention, there is provided a method of interconnecting an extruded or blow-moulded member to a fixture, comprising the steps of integrally forming a connection part on the extruded or blow-moulded member for inter-engaging the member and the fixture, and interlocking the inter-engaged part and member by use of separate interlock means.

According to the invention, there is further provided an extruded or blow-moulded member formed with an integrally extruded connection part for inter-engaging with a fixture, and interlock means for interlocking the inter-engaged connection part and the fixture.

Extruded and blow-moulded parts for use in motor vehicle body construction, and methods of connecting them, according to the invention, will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which: Figure 1 is a perspective longitudinal view, partly in section, of one of the parts showing its connection to another part; Figure 2 corresponds to Figure 1 but is an exploded view of the two parts before their connection; Figure 3 is a longitudinal view, partly in section, of a further one of the parts showing its connection to yet another one of the parts; and Figure 4 is an exploded view corresponding to Figure 3 but showing the two parts before their connection.

As shown in Figure 1, a pipe 4 is produced by a blow-moulding technique. In this example, the pipe 4 is a flexible pipe made of thermoplastic material and incorporating corrugations 6 to increase its flexibility; such a pipe may be used as an air duct, a cooling water hose or a fuel tank filler hose in a motor vehicle, for example. In use, the pipe 4 is to be secured to a tubular fixture 8, which could be a rigid tube or pipe associated with the air filter, cooling system or fuel tank of the vehicle, depending on the application. The fixture 8 may be produced (such as by injection-moulding) from suitable plastics material or may be made of metal or other suitable material.

In accordance with a feature of the invention, the pipe 4 is blow-moulded to have a integral connection part 5. The connection part 5 is designed and shaped to carry out two functions: (a) to facilitate a seal between the pipe 4 and the fixture 8; and (b) to facilitate a locking interconnection between the pipe 4 and the fixture 8. In this example, the connection part 4 has an end 10, a circumferential shoulder 12 and a circumferentially enlarged region 14. The region 14 merges with a circumferential 16 of lesser diameter having an end wall 18. An o-ring 21 is located within this groove 20. The circumferentially enlarged region 14 merges at its opposite axial end with a region 22 to define an end wall 24. Region 22 of the pipe in turn merges with the corrugations 6.

The rigid fixture 8 has stepped regions 26,28 and 30 of respectively increasing diameter. The fixture 8 is shown in this example as being fast with a pipe 31 having a branch pipe 32.

The end region 30 of the fixture 8 has an outwardly splayed mouth 34 which is provided with two slots 36 (see Figure 2).

The flexible pipe 4 is secured to the pipe 30 by inserting the connection part 5 through the mouth 34 of the fixture 8 as shown in Figure 1. The internal diameters of the circumferential regions 26,28 and 30 of the fixture 8 are sized to receive the distal end 10 of the connection part 5, its region including the groove 20 and the o-ring and the enlarged circumferential region 14, respectively. The internal diameter of the region 28 of the fixture 8 is sized to partially compress and thus seal against the o-ring 21. When the connection part 5 has been fully inserted as shown in Figure 1, it is secured to the fixture 8 by means of a resilient wire clip 40 which snaps into the slots 36 and engages against the end wall 24 of the connection part 5.

In this way, the two connectors are firmly secured together against subsequent separation, and the O-ring 21 ensures a good seal.

Such an interlocking arrangement provides a rapid means of connecting the flexible pipe 4 to the pipe 30 and avoids the use separate connectors which have to be welded, over-moulded, forcefitted onto the pipes, thus creating one or more supplementary interfaces with the pipes, such supplementary interfaces increasing the risk of failure or leakage and also being expensive.

Figure 3 shows a modified arrangement. In this example, the flexible pipe 4 has corrugations (not shown in Figures 3 and 4) to increase its flexibility, and a connection part 5. The connection part 5 has a distal end region 50 of reduced diameter which merges with a region 52 of enlarged diameter, the region 50 defining a circumferential groove 53 carrying an O-ring 54.

As shown in Figure 4, the enlarged region 52 is provided with an axially directed slot 56 which is open at one axial end and closed by a wall 58 at the opposite axial end. Two circumferential walls 60 and 61 extend partially around the enlarged region 52 to define a groove 64 which extends equally on both sides of the slot 56. Wall 60 merges with a pipe part 62 which, in turn, merges with the corrugations (not shown) of the pipe 4.

A separately moulded locking element 66 has one end shaped to be fitted and secured in the groove 64, so that its head 66A extends in cantilever fashion over the slot 56.

The fixture 8 is secured to or integral with a pipe 68. An intermediate circumferentially extending region 69 merges with an enlarged region 70 which has a part 72 of locally greater diameter. The part 72 defines a slot 76 (see Figure 3) and is formed with an aperture 78 (Figure 4).

In order to connect the pipes 4 and 68 together, the connection part 5 with the clip 66 in position thereon, is inserted into the enlarged part 72 of the fixture 8, with the two parts being angularly aligned with each other so that the clip 66 slides through the inverted slot 76 as shown in Figure 3. In order for this sliding movement to be possible, the enlarged head 66A of the clip 66 is bent downwards by contact with the inverted base of the slot 76, this bending being accommodated by the cantilevered body 66B of the clip 66. Relative axial movement of the connectors 5 and 8 continues until the distal end region 50 becomes located within the region 69, with the O-ring 54 being in sealing contact with this region. In this position, the head 66A of the clip 66 becomes located in alignment with the aperture 78 (Figure 4) and snaps into position within this aperture as shown in Figure 3. The two pipes cannot now be axially separated or moved radially with respect to each other.

Again, therefore, the two pipes can be rapidly connected together with the same advantages as specified in connection with the arrangement of Figures 1 and 2.

Claims

CLAIMS 1. A method of interconnecting an extruded or blow-moulded member to a fixture, comprising the steps of integrally forming a connection part on the extruded or blow-moulded member for inter-engaging the member and the fixture, and interlocking the inter-engaged part and member by use of separate interlock means.
2. A method according to claim 1, in which the separate interlock means interlocks with predetermined formations on the connection part and the fixture.
3. A method according to claim 2, in which the separate interlock means engages a slot which constitutes one of the formations, and, when so engaged, abuts against a shoulder which constitutes the other formation.
4. A method according to claim 2, in which the separate interlock means is resiliently mounted on one of the predetermined formations and biassed into engagement with the other thereof.
5. A method according to any preceding claim, including the step of providing a seal between the member and the fixture.
6. A method according to any preceding claim, in which the extruded or blow-moulded part is made of thermoplastic material.
7. An extruded or blow-moulded member formed with an integrally extruded connection part for inter-engaging with a fixture, and interlock means for interlocking the inter-engaged connection part and the fixture.
8. A member according to claim 7, in which the interlock means is separate from the member and the connection part.
9. A member according to claim 8, in which the member and the fixture are tubular and the connection part is an integral extension of the member.
10. A member according to any one of claims 7 to 9, in which one of the connection part and the fixture is inserted in the other thereof to a predetermined extent.
11. A member according to claim 10, in which the said other of the connection part and the fixture is provided with aperture means for receiving the interlock means to engage with a surface on the said one of the connection part and the fixture to prevent separation of the connection part and the fixture.
12. A member according to claim 11, in which the aperture means comprises at least one slot and in which the interlock means is in the form of a spring wire clip.
13. A member according to claim 10, in which the interlock means is attached to the said one of the connection part and the fixture and is resilient to allow it to be bent against its resilience during insertion of the said one of the connection part and the fixture into the other thereof, the said other thereof having aperture means into which part of the interlock means resiles.
14. A member according to any one of claims 10 to 13, in which the connection part is inserted into the fixture.
15. A member according to any one of claims 7 to 14, in which the connection part includes means for locating a sealing member for sealing between the connection part and the fixture.
16. A member according to any one of claims 7 to 15, at least partly in the form of a flexible corrugated pipe, the fixture being of open-ended tubular form.
17. A method of interconnecting an extruded or blow-moulded pipe with a tubular fixture, substantially as described with reference to the accompanying drawings.
18. An extruded or blow-moulded pipe for connection to a tubular fixture, the extruded or blow-moulded pipe being substantially as described with reference to the accompanying drawings.