GB2217417A

GB2217417A - A snap-locking releasable pipe connector

Info

Publication number: GB2217417A
Application number: GB8808725A
Authority: GB
Inventors: Mark Snowton
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1988-04-13
Filing date: 1988-04-13
Publication date: 1989-10-25
Also published as: GB8808725D0

Abstract

A pipe connector for connecting inter alia fuel lines in a motor car has a female, sleeve part 218 and a male, insert part 216. The male part is located on a pipe 212 and engages with the internal wall of the sleeve 218 such that a snap-locking action is produced. This snap-locking action is repeated at a number of axial positions as the pipe is inserted, but the first point where the snap-locking action takes place occurs before the end of the pipe makes contact with the connector seal 226. <IMAGE>

Description

A Pipe Connector This invention relates to a pipe connector for connecting two pipes together. The invention is particularly suitable for use where a metal or other rigid pipe is to be connected to a flexible pipe, and an example of such an application is in the fuel line between the fuel tank and the engine of a motor vehicle.

In order to provide for efficient assembly line practice, it is important that fuel line and pipe joints can be made rapidly and correctly. Conventional connectors perform two functions; firstly they make a seal between the two pipes, and secondly they provide a mechanical lock to prevent the pipes from being accidentally separated. It is desirable that the joint be capable of being made without any tools, and that it should also be capable of being disassembled for servicing and repair, also without these tools.

According to the present invention there is provided a pipe connector for connecting two pipes end to end, the connector comprising a first part to be fitted to one pipe end, a second part to be fitted to the other pipe end and a seal member which forms a seal, wherein the first and second parts are arranged so that they connect together by a push-fit action and wherein a snap-locking action takes place as the pipes are connected, first in one and then in another of at least two axially spaced snap-locking locations and wherein the snap-locking action first takes effect when one pipe end is partially pushed into the second part and before the seal member is able to make a seal.

In this way it is impossible for the pipes to be sealed to one another without their being locked to one another but it is possible for the pipes to be locked together without being sealed. If they are locked to one another without a seal being created, then the fact that there is a bad connection will be immediately apparent upon initial testing of the vehicle.

Preferably the first part is a male part and the second part is a female part, and the female part includes the seal member which may 'take the form of two 0 rings arranged side by side. The female part can end in a hollow spigot over which the end of the flexible pipe is fitted and secured.

The first part may be received first in the second part, before the pipe end is introduced into the first part, or alternatively the first part can be initially fitted to the respective pipe end and then introduced into the second part.

The first part preferably has external circumferential ribs which co-operate with an inwardly directed resiliently mounted tooth on the second part, so as to create a ratchet effect as the first part is pushed into the second part which resists movement of the second part out of the first part.

There may be more than one resiliently mounted tooth on the second part, and the teeth may be axially spaced relative to one another by a distance less than the distance between the ribs on the first part.

The ribs on the first part preferably have a saw-tooth profile.

The first part may be in the form of a split ring so that it can be snapped onto a pipe. The ring preferably has an internal recess between its ends for receiving an annular projection on the pipe and for retaining the second part on the pipe.

In order to guide the tip of the pipe into the second part of the connector, without damaging the seal member, the second part may include a moulded-in ramp or tubular guide to direct the pipe into correct engagement with the seal member.

The resiliently mounted tooth or teeth on the second part are preferably connected to the body of the second part by an integral hinge, and the hinge lies between the active part of the tooth and the mouth of the second part. The tooth is preferably connected to a radially projecting lug which can be moved to disengage the tooth from the second part and to allow disassembly of the connector.

In an alternative embodiment, the snap-locking action takes place between an external rib formed on the pipe and a number of internal ribs formed on the first part. The first part can have one snap-locking position in the second part, and the internal teeth formed on the first part can be axially spaced to allow a snap-locking action to take place at a plurality of positions.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic drawing of two pipes and a pipe connector in accordance with the invention shown with the joint uncoupled; Figure 2 is an enlarged sectional view through the connector of Figure 1 in a first position; Figure 3 is a view similar to Figure 2 but showing the pipes fully connected; Figure 4 shows a detail between the first and second parts of the connector; Figure 5 is a side view of the first connector part; Figure 6 is a view corresponding to Figure 3, but showing a second embodiment of the invention; Figure 7 shows part of a connector for use in a third embodiment of the invention; Figure 8 is a view corresponding to Figure 1 but showing the third embodiment of the invention;; Figure 9 is a view corresponding to Figure 2 again showing the third embodiment of the invention; Figure 10 is a view corresponding to Figure 3 showing the third embodiment of the invention; and Figure 11 is a side view of an alternative construction of the outer sleeve.

Figure 1 shows a nylon fuel line 10 which is to be connected to a steel fuel line 12 by a connector 14. The connector has a first, male part 16 and a second, female part 18 and the steel fuel line 12 has annular ribs 20 formed on it by a conventional upsetting process. The right hand end of the female part 18 has a hollow spigot 22 and the nylon line 10 is pushed over this spigot.

The female part 18 has an internal cavity 24 and two nitrile rubber 0-rings 26 are-located in the cavity. The male part 16 of the connector is shown in the cavity and it will be seen that the internal surface of this part has a number of inwardly projecting teeth 28 which engage with the ribs 20 as shown. Figure 2 shows the first rib 20 having engaged with the first tooth 28 so that the pipe 12 is now snap-locked into the female part 18. At this point however there is no seal effective on the end of the pipe 12 because the end of the pipe has not yet reached the 0rings 26.

Figure 3 shows the next stage in connection, where the pipe 12 has been pushed fully home and the 0-rings 26 now seal against the outside surface of the pipe so that a fluid tight joint is formed between the pipes 10 and 12.

Figure 4 illustrates how the male part 16 is held inside the female part 18. The section of Figure 4 is taken at a position 90x away from the section shown in Figures 2 and 3 and shows an outwardly directed lug 30 on the part 16 engaging in an annular recess 32 in the part 18. As the part 16 is pushed in, so the lug 30 will snap into the recess 32 and will resist outward movement of the part 16.

However in order to allow the parts to be separated subsequently, an ear 34 is formed on the part 16 and a reduced thickness region 36 forms a hinge. When the ears 34 are pulled inwards, the lugs 30 will be deflected from a position close to the hinge so that the male part can be pulled out. There will be two of the ears 34 as can be seen in Figure 1.

Figure 5 is a plan view of the male member 16 from the outside. This view shows a number of circumferentially spaced teeth 28, with each set of teeth being axially spaced from its neighbour. The ridges 20 on the pipe will engage with each of these sets in turn as the pipe is pushed in so that a wide range of locked positions of the pipe 12 is possible.

Figures 2 and 3 also show that the innermost end of the part 16 has a guide ramp 38 which will assist in directing the innermost end of the pipe 12 centrally in the connector so that it does not damage the 0-rings as it is inserted.

In order to prevent the 0-rings being withdrawn with the pipe 12 on disassembly, the wall of the cavity 24 is provided with an internal bead 40.

Figure 6 shows an alternative embodiment where the male part 116 has internally projecting teeth 128, only one of which is shown in the Figure, which engage with a rib 20 on the pipe 12. The male part 116 also has a multiposition snap-locking relationship with the female part 118. A resiliently mounted pawl 142 is formed as part of the female part 118 and performs a ratchet action with a set of teeth 144 on the outside of the male part 116. In this embodiment, the part 116 is first assembled in the female part 118 and the pipe 12 is then introduced until the rib 20 is engaged by a tooth 128. As before, the position of the rib 20 and of the teeth 128 are such that the pipe is locked in the connector before a seal is made with the pipe.

when the connector is disconnected in service, the pawl 142 will be lifted and the inner part 116 will be withdrawn together with the pipe. The length of the toothed portion 144 will be such that, on re-assembly, a first locking position between the pawl 142 and the toothed portion 144 is reached before the pipe 12 is sealed in the connector.

This concept is taken further in Figures 7 to 10, where a male part 216 is initially fitted on the steel line 212.

The part 216 has a toothed external surface and has a split circumference so that it can be snap-fitted over a ridge 220 formed on the pipe 212. Figure 8 shows the insert 216 in position on a pipe, and Figure 9 shows the internal shape of the insert. The insert has four angularly spaced internal ribs 246 which define an annular groove 248 in which the annular ridge 220 is received.

The first stage in assembly is therefore to fit the insert 216 onto the pipe 212 so that it is retained thereon.

Next, the pipe is introduced into the sleeve 218 which has an internally projecting, resiliently mounted pawl 242 connected to the rest of the sleeve 218 by an integral plastics hinge 250. Figure 9 clearly shows that when the pawl 242 is engaged with the first notch on the toothed rack 244, then the end of the pipe 212 does not yet seal with the 0-rings 226. However on further insertion as illustrated in Figure 10, sealing takes place. As in Figure 6, the connection can be dismantled by manually lifting the pawl 242 and withdrawing the pipe with the insert 216.

Two alternative methods of guiding the end of the pipe into the sleeve are shown. In Figure 9, an internal rib 252 is fitted in the cavity 224 and will both guide the pipe and also act as a retention lip for the 0-rings 226 on disassembly.

In Figure 10, an internal spigot 254 extends axially past the 0-rings and ensures that the pipe 212 is introduced past the 0-rings coaxially.

Figure 11 shows an embodiment which guards against the remote possibility that the pipe might be assembled into the female part 318 without the correct male part. Here the pawl 342 is moulded so that it initially extends into the opening of the sleeve 318. when a pipe is correctly fitted with a collar such as 216, introduction of the collar will tip the pawl about its integral hinge 350 so that the position of Figure 10 will be achieved. However if the pipe 312 with its rib 320 is inserted alone, then the pawl will provide a mechanical lock with the rib as illustrated.

It is of fundamental importance to the invention that the first engagement of the locking means (as shown respectively in Figures 2 and 9 for the first and third embodiments) occurs before the pipe 12 or 212 comes into contact with the 0-rings 226. In other words, the distance from the end of the pipe to the effective point of first locking is less than the distance from the 0rings to the point of first locking.

Claims

1. A pipe connector for connecting two pipes end to end, the connector comprising a first part to be fitted to one pipe end, a second part to be fitted to the other pipe end and a seal member which forms a seal, wherein the first and second parts are arranged so that they connect together by a push-fit action and wherein a snap-locking action takes place as the pipes are connected, first in one and then in another of at least two axially spaced snap-locking locations and wherein the snap-locking action first takes effect when one pipe end is partially pushed into the second part and before the seal member is able to make a seal.

2. A pipe connector as claimed in Claim 1, wherein the first part is a male part and the second part is a female part, and the female part includes the seal member.

3. A pipe connector as claimed in Claim 2, wherein the seal member takes the form of two 0-rings arranged side by side.

4. A pipe connector as claimed in any preceding claim, wherein the female part ends in a hollow spigot over which the end of the flexible pipe can be fitted and secured.

5. A pipe connector as claimed in any preceding claim, wherein the first part is received in the second part, before the pipe end is introduced into the first part.

6. A pipe connector as claimed in any one of Claims 1 to 4, wherein the first part is initially fitted to the respective pipe end and then introduced into the second part.

7. A pipe connector as claimed in Claim 6, wherein the first part has external circumferential ribs which cooperate with an inwardly directed resiliently mounted pawl on the second part, so as to create a ratchet effect as the first part is pushed into the second part which resists movement of the second part out of the first part.

8. A pipe connector as claimed in Claim 7, wherein there is more than one resiliently mounted pawl on the second part, and the pawls are axially spaced relative to one another by a distance less than the distance between the ribs on the first part.

9. A pipe connector as claimed in any one of Claims 6 to 8, wherein the ribs on the first part have a saw-tooth profile.

10. A pipe connector as claimed in any one of Claims 6 to 9, wherein the first part is in the form of a split ring so that it can be snapped onto a pipe.

11. A pipe connector as claimed in Claim 10, wherein the ring has an internal recess between its ends for receiving an annular projection on the pipe and for retaining the second part on the pipe.

12. A pipe connector as claimed in any one of Claims 7 to 11, wherein the resiliently mounted pawl or pawls on the second part are connected to the body of the second part by an integral hinge, and the hinge lies between the tip of the pawl and the mouth of the second part.

13. A pipe connector as claimed in Claim 12, wherein the pawl or pawls are moulded in one piece with the second part and are arranged so that in the as moulded state substantially the whole of at least on of the pawls projects into the internal cavity of the second part.

14. A pipe connector as claimed in Claim 12 or Claim 13, wherein the or each pawl is connected to a radially projecting lug which can be moved to disengage the pawl from the second part and to allow disassembly of the connector.

15. A pipe connector as claimed in Claim 5, wherein the snap-locking action takes place between an external rib formed on the pipe and a number of internal ribs formed on the first part.

16. A pipe connector as claimed in Claim 15, wherein the first part has a single snap-locking position in the second part, and the internal teeth formed on the first part are axially spaced to allow a snap-locking action to take place against a rib on one pipe end, at a plurality of axially spaced positions.

17. A pipe connector as claimed in any preceding claim, wherein the second part includes a moulded-in ramp or tubular guide to direct the pipe into correct engagement with the seal member.

18. A pipe connector substantially as herein described with reference to any one embodiment shown in the accompanying drawings.