GB2060106A

GB2060106A - Quick Release Tube Coupling

Info

Publication number: GB2060106A
Application number: GB7935113A
Authority: GB
Original assignee: Britton Ltd C E & J P
Current assignee: Britton Ltd C E & J P
Priority date: 1979-10-10
Filing date: 1979-10-10
Publication date: 1981-04-29

Abstract

In a tube coupling of the kind having a body formed with a socket 3 for receiving an end portion of a tube 12 and a retaining ring 13 in the socket which grips and/or bites into the surface of the tube to retain it in the socket, an annular releasing member 20 is provided whereby a retained tube can be quickly released from the socket. The releasing member 20 is axially movable relative to the body 1 to cause an abutment part or parts 24 of the member, acting through the intermediary of a sealing ring 19, to deflect the retaining member out of engagement with the tube. The sealing ring 19 seals the connection of a tube to the coupling as soon as the tube is pushed through it, and because the retaining member engages with the tube after the sealing ring it cannot cause marking at the part of the surface of the tube engaged by the sealing ring which could impair the effectiveness of the seal. Preferably a spacer 17 is interposed between the sealing ring 19 and retaining ring 13 which co- operates with the teeth or like parts of the retaining ring to cause them to be deflected out of engagement with the tube when the releasing member is operated. At the opposite side of the retaining ring to the sealing ring there may be a further sealing ring (not shown) which may also be separated from the retaining member by a spacer. <IMAGE>

Description

SPECIFICATION Tube Coupling This invention relates to tube couplings of the kind having a body in which there is a socket adapted to receive and locate an end portion of a tube and containing a retaining ring which grips and/or bites into the external surface of the end portion of the tube to be connected to retain the end portion in the socket. Such couplings are hereinafter referred to as "of the kind described".

They are particularly suitable for use with tubes made of plastics material, although they may also be used with metal tubes, and they are applicable to tubes having plain end portions.

There is a need by plumbers and less skilled handymen for a coupling of the kind described which as well as providing a sound seal enables a tube to be easily and quickly connected and disconnected from the coupling. It is the primary object of the present invention to provide a coupling which meets the need.

According to the present invention a tube coupling is provided of the kind described in which an annular releasing member is carried by the body co-axially of the socket, has an abutment part or parts extending into the socket and is movable relative to the body to move the abutment part or parts axially of the socket, and a sealing ring is housed in the socket intermediate the abutment part or parts and the retaining ring, the arrangement being such that axial movement of the abutment part or parts towards the retaining ring can be transmitted by means of the sealing ring to the retaining ring to cause the retaining ring to be deflected away from the axis of the socket, thereby enabling a tube which has been retained in the socket by the retaining ring to be released from the socket.

Connection of a tube to the coupling now provided can be effected readily simply by pushing its end portion into the socket and through the sealing ring and retaining ring. The sealing ring effectively seals the connection as soon as the end portion is pushed through it. As the end portion engages the retaining ring only after it has engaged with the sealing ring, any scoring, indenting or other marking produced on the surface of the end portion by the retaining ring is in front of the sealing ring and cannot reduce the effectiveness of the sealing contact of the sealing ring with the end portion. So far as disconnection of a tube from the coupling is concerned, when once the retaining ring has been deflected by movement of the releasing member so as to disengage the ring from the tube, the tube can be drawn back through the sealing ring and out of the socket without difficulty.Using a preferred form of the tube coupling, both connection and disconnection may be carried out without having to use tools.

The releasing member is preferably of similar form to the releasing member included in the tube coupling which is the subject of our Patent Application No. 22184/77. Thus, only the abutment part or parts of the releasing member need extend into the socket, and the member may comprise a cap-like component which fits over the body. Preferably the member is slidable by hand on the body to effect the required movement for releasing the retaining ring. The member may have a tubular abutment part coaxial with the socket, it may have angularly spaced fingers, prongs or the like which serve as the abutment parts, or it may have an abutment part or parts of other convenient forms.

There may be direct engagement of the abutment part or parts with the sealing ring, or a spacer member, such as a washer, may be interposed between them.

Conveniently, the sealing ring is an O-ring of resilient rubber or plastics material. Other suitable forms of sealing ring may be used, and where the releasing member has a tubular abutment part the ring may possibly be integral with the abutment part, for example as a resilient flange or skirt portion projecting from the abutment part and adapted to embrace closely a tube pushed into the socket through the abutment part.

Again there may be direct engagement of the sealing ring with the retaining ring, but preferably an intermediate member is disposed between, and arranged to be engaged by, both rings. The intermediate member may be of modified washer form, or sleeve form, having a portion which engages with the radially inner part of the retaining ring in order to deflect that part away from the axis of the socket when the releasing movement of the releasing member is transmitted by means of the sealing ring to the intermediate member.

The retaining ring may be of conventional, or substantially conventional, form made of spring sheet metal with teeth or like parts which engage the tube to be retained in the coupling in use.

Attachment of the releasing member to the body may be relied upon to maintain the retaining ring, and also the sealing ring and, if provided the spacer and intermediate members, in the socket during use of the coupling. Alternatively, the retaining ring may be located in the socket against removal by snapping its radially outer portion into a groove in the wall of the socket or under an undercut or other abutment on the socket wall, or it may be permanently fixed in the socket by moulding, casting or welding its radially outer portion into the wall of the socket, depending upon the material of which the body is made. Where attachment of the releasing member by snapping under an undercut or other abutment maintains the retaining ring in the socket, the retaining ring may seat on a shoulder in the socket.Another way in which the retaining ring may be held in position is to provide it with a tubular portion which fits over the exterior of the body and has an inwardly turned edge or their means which engages, conveniently by snap action, in a recess in, or behind a suitable abutment on, the body.

At the opposite side of the retaining ring from the sealing ring, a further sealing ring may be provided. The further sealing ring may be immediately next to the retaining ring, or a washer or other spacer may be inserted between them.

Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is an axial section through a tube coupling in accordance with the invention, Figure 2 is an axial section through a tube coupling according to the invention, and Figures 3 and 4 are fragmentary sectioned views showing two modifications.

Referring to Figure 1, the tube coupling has a cylindrical body 1 with an externally screw threaded spigot 2 of reduced diameter extending co-axially from one end, and having a co-axial socket 3 opening through the opposite end. An annular external shoulder 4 is defined on the body 1 facing towards the spigot 2. The socket 3 is counterbored such that an outer cylindrical stage 5 is provided extending from the mouth of the socket and an inner cylindrical stage 6 of smaller diameter communicating in two radially inwardly directed steps 7, 8 with a passage 9 extending co-axially through the spigot. An abrupt shoulder 10 is presented between the outer and inner stages, and the diameter of the outer stage 5 is enlarged to some extent next to the shoulder so that an annular undercut 11 is presented facing the shoulder.

The diameter of the inner stage 6 is complementary to the external diameter of a tube 12 which the coupling is designed to receive.

A retaining ring 13 of spring sheet metal seats on the shoulder 10 in the socket and snaps under the undercut 11 so that it is positively located in the socket. The retaining ring 13 has a cylindrical outer portion 14 of such height that it fits snuggly between the shoulder 10 and undercut 1 1, an annular portion 15 extending radially inwardly from the end of the cylindrical outer portion 14 adjacent to the undercut, and an inverted frustoconical inner portion 16 of less height than the cylindrical outer portion consisting of a number of angularly spaced teeth. The inner diameter of the inner portion 16 is slightly smaller than the external diameter of the tube 12.

Resting on the retaining ring is an intermediate member 17 in the form of a slightly tapering sleeve with an external annular flange 18 at its wider end. The narrower end of the sleeve rests on the frusto-conical inner portion 16 of the retaining ring 13 near the inner edges of the teeth. The flange 18 is spaced axially from the annular portion 15 of the retaining ring and is a sliding fit in the outer stage of the socket beyond the undercut 11.

An O-ring 1 9 is fitted in the outer stage 5 against the flange 18 of the intermediate member 17. The O-ring is a sealing fit in the outer stage and about the tube.

A releasing member 20 in the general form of a cap fits over the end of the body 1. It has a skirt portion 21 which extends slidably over the outside of the body and an annular internal lip 22 which snaps into engagement with the external shoulder 4, thereby to retain the releasing member on the body whilst permitting limited axial movement of the member on the body. An annular crown portion 23 of the releasing member extends over the mouth of the socket and has a central tubular abutment portion 24 which projects into the socket and engages with the O-ring 19. In the normal position of the releasing member, as shoWn in Figure 1 , the crown portion 23 is spaced from the end of the body.

The tube 12 is connected to the coupling simply by pushing it into the socket, through the O-ring, intermediate member and retaining ring, until its end abuts against the step 7 at the end of the inner stage 6. The teeth of the retaining ring grip and/or bite into the surface of the tube as it is pushed through the ring and retain the tube securely in the socket. The O-ring effectively seals the connection. The tube 12 may be of plastics or metal with a plain square cut end.

If at any time the tube is required to be released from the coupling, this can be readily effected by means of the releasing member. By manually pushing the releasing member towards the body, the tubular abutment portion 24 bears on and urges the O-ring towards the intermediate member, which is in turn urged towards the retaining ring. The intermediate member causes the teeth of the inner portion 15 of the retaining ring to be deflected radially outwardly and out of contact with the tube, so that the tube can then be pulled out of the socket.

In the embodiment shown in Figure 2 of the drawings, the coupling is substantially similar to the embodiment of Figure 1 and corresponding parts are indicated by the same reference numerals. The main difference is that the outer stage 5 of the socket 3 is not formed with an undercut, and in fact the diameter of the outer stage is shown as reduced slightly next to the shoulder 10. In this instance the retention of the releasing member 20 on the body alone is relied upon to hold the retaining ring 13 secure in the socket As the diameter of the outer stage is reduced next to the shoulder the retaining ring is made narrower by omitting the annular portion so that the toothed inner portion 1 6 is joined directly to the cylindrical outer portion 14.

The modification shown in Figure 3 has the outer stage 5 of the socket 3 of constant diameter except for an intermediate annular bead or rib 25.

The retaining ring 13 snaps under the bead or rib 25 and is thus positively retained in the socket 3.

Between the shoulder 10 and the retaining ring 13 are fitted a further O-ring 26 and a washer 27.

The further O-ring seats on the shoulder, the washer rests on that O-ring and the retaining ring seats on the washer.

Referring now to Figure 4, the modification primarily concerns the inner stage 6 of the socket 3 and the form of the retaining ring. Other parts of the coupling are substantially unchanged and are identified by the same reference numerals as in the above-described embodiments. The inner stage 6 is of larger diameter than the tube 12. The retaining ring 13, whilst having a toothed frustoconical inner portion 16 and an annular portion 15, has the annular portion joined to the opposite end, the lower end as illustrated, of a cylindrical outer portion 28. The annular portion seats on the shoulder 10 between the inner and outer stages of the socket and the frusto-conical inner portion 16 extends into the inner stage 6 to engage the tube 12.As in the previous embodiments the narrower end of the sleeve of the intermediate member 17 normally rests on the inner portion of the retaining ring, and the external flange 18 is spaced just above the upper end of the cylindrical outer portion 28 of the retaining ring. The clearance between the external flange 18 and the outer portion 28 is sufficient to allow enough downward movement of the intermediate member 17 when the releasing member 20 is operated for the sleeve to deflect the teeth of the inner portion 1 6 of the retaining ring outwards from engagement with the tube. The outer stage of the socket is shown in the drawing as being of constant diameter throughout its length so that, as in Figure 2, the retention of the releasing member 20 on the body is relied upon to hold the retaining ring 13 in the socket. The outer stage may alternatively be provided with an undercut as in Figure 1 or a bead or rib as in Figure 3 to retain the ring in the socket.

Claims

1. A tube coupling of the kind described in which an annular releasing member is carried by the body co-axially of the socket, has an abutment part or parts extending into the socket and is movable relative to the body to move the abutment part or parts axially of the socket, and a sealing ring is housed in the socket intermediate the abutment part or parts and the retaining ring, the arrangement being such that axial movement of the abutment part or parts towards the retaining ring can be transmitted by means of the sealing ring to the retaining ring to cause deflection of the retaining ring away from the axis of the socket, thereby enabling a tube which has been retained in the socket by the retaining ring to be released from the socket.

2. A tube coupling according to Claim 1 wherein the releasing member comprises a caplike component having the abutment part or parts and which fits over the body and is movable on the body to effect the required movement of the releasing member.

3. A tube coupling according to Claim 1 or Claim 2 wherein the releasing member is slidable on the body to move the abutment part or parts axially of the socket.

4. A tube coupling according to any preceding claim wherein the releasing member has a tubular abutment part co-axial with the socket.

5. A tube coupling according to any of Claims 1 to 3 wherein the releasing member has angularly spaced fingers, prongs or like elements which constitute the abutment parts.

6. A tube coupling according to any preceding claim wherein the or each abutment part directly engages with the sealing ring.

7. A tube coupling according to any of Claims 1 to 5 wherein a spacer member is interposed between the abutment part or parts and the sealing ring, the arrangement being such that axial movement of the releasing member towards the retaining ring causes the spacer member to be moved axially of the socket by the abutment part or parts and the spacer member causes the retaining ring to be deflected.

8. A tube coupling according to Claim 7 wherein the spacer member comprises a sleeve portion which engages at one end with the releasing member and has an annular flange at its opposite end on which the sealing ring seats.

9. A tube coupling according to Claim 8 wherein the sleeve portion tapers away from the annular flange.

10. A tube coupling according to any preceding claim wherein the retaining ring has a cylindrical portion which extends co-axially of the socket adjacent the circumferential wall of the socket, and has teeth or like parts projecting from the cylindrical portion towards the axis of the socket which are adapted to engage with the external surface of a tube to retain the tube in the socket, and which are caused to be deflected away from the axis of the socket by movement of the abutment part or parts towards the retaining ring.

1 A tube coupling according to Claim 10 as dependent from Claim 9 wherein the narrower end of the sleeve portion of the spacer member engages with the teeth or like parts of the retaining ring.

12. A tube coupling according to Claim 10 or Claim 11 wherein the retaining ring has a frustoconical inner portion disposed within the cylindrical portion and at which the teeth or like parts are defined.

13. A tube coupling according to Claim 10 or Claim 11 wherein the retaining ring has a frustoconical inner portion projecting axially away from the cylindrical portion and at which the teeth or like parts are defined.

14. A tube coupling according to Claim 12 or Claim 13 wherein the inner portion projects from an annular portion of the retaining ring extending radially inwardly from one end of the cylindrical portion.

15. A tube coupling according to any of Claims 10 to 14 wherein the socket has a shoulder on which the retaining ring seats.

16. A tube coupling according to any of Claims 10 to 15 wherein the socket has an undercut in its cylindrical surface with which the retaining ring has a snap engagement which retains the retaining ring in the socket.

17. A tube coupling according to any of Claims 10 to 15 wherein the socket has a projection on its cylindrical surface under which the retaining ring has a snap engagement which retains the retaining ring in the socket.

18. A tube coupling according to any of Claims 1 to 9 wherein the retaining rings has a radially outer portion which is fixedly embedded in the circumferential wall of the socket.

19. A tube coupling according to any of Claims 1 to 10 wherein the retaining ring has a tubular portion which fits over the exterior of the body and has an inwardly directed part which engages, or parts which engage, in a recess in, or behind an abutment on, the body, thereby to retain the retaining ring to the body.

20. A tube coupling according to any preceding claim wherein at the opposite side of the retaining ring from the sealing ring a further sealing ring is provided in the socket, the further sealing ring being immediately next to the retaining ring.

21. A tube coupling according to any of Claims 1 to 19 wherein at the opposite side of the retaining ring from the sealing ring a further sealing ring is provided in the socket and a spacer is inserted between the retaining ring and the further sealing ring.

22. A tube coupling substantially as described herein with reference to and as illustrated by Figure 1 of the accompanying drawings.

23. A tube coupling substantially as described herein with reference to and as illustrated by Figure 2 of the accompanying drawings.

24. A tube coupling substantially as described herein with reference to and as illustrated by Figure 3 of the accompanying drawings.

25. A tube coupling substantially as described herein with reference to and as illustrated by Figure 4 of the accompanying drawings.