GB2195159A

GB2195159A - Lockable coupling for pipes

Info

Publication number: GB2195159A
Application number: GB08721859A
Authority: GB
Inventors: Vincent Mignet; Pierre Vigneron
Original assignee: Pont a Mousson SA
Current assignee: Pont a Mousson SA
Priority date: 1986-09-17
Filing date: 1987-09-17
Publication date: 1988-03-30
Anticipated expiration: 2007-09-17
Also published as: GB8721859D0; GB2195159B; ES2008736A6; BR8704788A; IT8767792A0; FR2603972B1; ATA235087A; DE3730968A1; IT1211306B; KR880004268A; FR2603972A1; AT395753B

Description

1 GB2195159A 1

SPECIFICATION

Lockable coupling for pipes The present invention relates to a lockable coupling for pipes. It may be a question in particular of pipes intended to be buried, made from centrifugally cast metal, according to well-known techniques. As regards the locking, its object is to prevent any relative axial movement between the pipes under the effect of their internal pressure or under the effect of forces which may act on them externally. In view of the high risk of corrosion, it is important that lockable couplings of this type may be made without using screwed segments and generally without using bolts. Furtherm&e, they should be as simple as possible and be assembled or dismantled with a minimum amount of tools and labour and without any complications as regards their manufacture.

At present, lockable couplings for pipes are known, of the type comprising firstly, at the joining end of one of them, a male end intended to be introduced into the housing of a female socket provided at the joining end of the other pipe, a gasket intended to ensure water-tightness between the two pipes being disposed on the inner periphery of the said housing in order to be compressed on the outer periphery of the male end, when the latter is introduced into the said socket and secondly, means for locking the male end in the socket, intended to prevent any relative axial movement between the said pipes, these means comprising a collar surrounding the male end, retained axially on the latter in order to be prevented from sliding towards its join- ing end and an outer flange provided at the end of the female socket and able to penetrate and to be locked in a recess provided in the said collar around the male end.

In order to ensure locking of the outer which ensures that the axial locking obtained is preserved.

These devices have the desired simplicity as regards their use, but have a complicated manufacture. Indeed, the fact that the flange of the female socket is provided with radial lugs instead of being completely a part of revolution, makes it necessary either to modify the centrifugal casting mould, or to produce a flange of revolution and then to form slots therein by machining. In both cases it is a question of an expensive complication which the present invention proposes to eliminate.

The object of the present invention is in particular to be able to preserve a locking de vice of the bayonet type, but with a flange which is completely a part of revolution, that is to say which may be formed by a conven tional operation of centrifugal casting, without modifying the mould and without subsequent machining.

To this end, a lockable coupling for pipes of the type described above will be characterised essentially according to the present invention in that the said locking means comprise a ring having a circular opening enabling it to be en gaged on the said female socket coming to bear behind the said flange comprised by the end of this socket, this flange being com pletely a part of revolution and in that the said ring comprises externally, on its periphery, a succession of alternate lugs and slots able to co-operate, according to the so-called -bayo net- system with alternate lugs-directed ra dially inwards-and corresponding slots, pro vided on the said collar at the entrance to its recess.

The axial locking between the two pipes may thus be obtained as simply as with the known locking device, by a simple rotation of the said collar of the male end with respect to the ring of the socket, this collar rotating on the female socket.

After the axial locking is achieved in this flange of the socket in the recess in the col- 110 way, in order to prevent a rotation of the ring lar, in these known lockable couplings it is or of the collar, it can also be provided that at provided that the said collar may rotate along least one of the lugs of the said ring-prefer the axis of the male end and thus co-operate ably that which is the highest after lock with the flange of the female socket according ing-comprises on its outer periphery a to a well-known, so-called -bayonet- locking 115 groove directed parallel to the axis of the system. In order to do this, it is sufficient to pipes and able to be located, once locking is provide at the entrance to the recess in the achieved, opposite a similar groove passing collar, lugs directed radially inwards, separated through the said collar at the level of the cor by slots, which slots may be penetrated by responding lug in the latter, an angular locking external radial lugs constituting-with other 120 cotter thus being able to be engaged in the slots which separate them the flange of the housing formed by the two grooves.

female socket. When the lugs of the flange This cotter will naturally prevent any acci have penetrated the recess in the collar pass- dental rotation of the ring with respect to the ing through the slots of the latter, in order to collar and thus any accidental axial unlocking obtain the desired axial locking, it is therefore 125 between the pipes, but it may also serve as sufficient to rotate the collar sufficiently in orevidence of the fact that locking has been der that its radial lugs are located exactly be- achieved satisfactorily. The simple verification hind the corresponding outer lugs of the of its presence in the two grooves in question flange. A locking device for preventing rota- will in fact confirm the safety of the axial lock tion may then prevent the collar from turning, 130 ing. In addition, having no need to be 2 GB 2 195 159A 2 wedged, since it does not have to participate directly in the axial locking, this cotter will be as easy to extract as to put in position.

One embodiment of the invention will now be described as a non-limiting example, refer ring to the accompanying drawings in which:

Figure 1 is a view in half axial section, on line 1-1 of Figure 2, of a coupling according to the present invention, shown in the locked state; Figure 2 is a partial view of the coupling, in cross-section on line 11-11 of Figure 1; Figure 3 is a front view, to a smaller scale, of the ring; 15- Figure 4 is an end view, to a smaller scale, 80 of the collar, in the direction of arrow F of Figure 1; and Figures 5 and 6 are views in half axial sec tion of the coupling, respectively on lines V-V and VW1 of Figure 2.

In the drawings, the reference numeral 1 designates a male end of a pipe, introduced into the housing 2 of a female socket 3 pro vided at the joining end of another pipe. In order to ensure the tightness of the connec tion between these two pipes, a gasket 4 of elastomeric material or the like is compressed between the bottom of an inner peripheral groove 5 in the housing 2 and the outer per ipheral surface of the end 1.

Engaged on this same end 1 is a collar 6 which - is prevented from sliding axially towards the extremity of the male end by the abut ment of the edge of its central passage 7 3 5 against a retaining ring 8, which is fixed to the male end by a peripheral weld bead 9 (see Figure 1). Internally, the shape of the col lar 6 is such that a recess 10 is provided between the outer surface of the end 1 and a spherical portflon 11 of the inner surface of the collar, following the passage 7. This re cess 11 passes through the collar and opens out beneath an enlarged section of the side remote from the passage 7.

It should be noted here that, in known man- 110 ner, the spherical portion 11 of the collar 6 may co-operate by sliding with a correspond ing spherical portion 12 of the ring 8, so that a slight pivoting of the axis of one of the pipes with respect to the axis of the other pipe will be allowed, tightness in any case being ensured by the resilient gasket 4.

As regards the locking means proper, their essential function will be to nsure locking, in the recess 10 of the collar 6, of an outer peripheral flange 13, which is entirely a part of revolution, comprised by the end of the female socket 3.

To this " end a ring 14 is used which is engaged on the socket 3 by its circular open- 125 ing 15 and which, after introduction into the said recess 10 of the collar 6 may, by a rotation, be arranged to be locked axially be tween the flange 13 and radial lug 16, di rected inwards, which the collar comprises at 130 the entrance to its recess 10. In order to obtain this locking according to the well-known, so-called---bayonet-system, this ring 14 cornprises on its outer periphery, a succession of alternate lugs and slots, bearing the reference numerals 17 and 18 (Figure 3).

This being so, it goes without saying that the introduction of the ring 14 into the recess 10 in the collar 6 will be easily obtained by sliding of the ring on the socket 3, until it abuts against the flange 13, consequently that the ring will be orientated in such a manner that its lugs 17 each arrive opposite the corresponding slot 19 separating two consecutive lugs 16 of the collar (see Figure 4); a simple rotation of the collar 6 will then bring its lugs 16 exactly in front of the lugs 17 of the ring (Figure 2), which will ensure the abovementioned axial locking effect and thus locking of the female socket 3 in the collar 6 and locking of the two pipes.

Thus, in order to prevent any accidental rotation of the ring 14 or of the collar 6 and thus a risk of accidental axial unlocking of the pipes, a cotter 22 may finally be engaged in the housing formed by the arrangement of a groove 20 formed in a lug 17 of the ring 14 and the complementary groove 21 in facing relationship, provided in the corresponding lug 16 of the collar (see in particular Figures 1 to 4). A groove 20 may be provided in each of the lugs 17 of the ring 14, which, at the time of assembly, will make it possible to bring any lug 17 to the level of the groove 21 in the collar. In any case, it is particularly advantageous that, for the above-mentioned reason of visualisation, the groove 21-and thus the cotter 22-are situated on the upper part of the coupling, as has been shown in the draw- ings.

According to a variation of. the invention particularly suitable for fitting a coupling having two sockets, the ring 14 may be constituted by an incomplete split ring of sufficient elasticity to enable the latter to be positioned by the nose of the socket 3 by making its inner diameter greater than the outer diameter of the flange 13.

Claims

1. Lockable coupling for pipes, of the type comprising firstly, at the joining end of one of them, a male end intended to be introduced into the housing in a female socket provided at the joining end of the other pipe, a gasket intended to ensure water- tightness between the two pipes being disposed on the inner periphery of the said housing in order to be compressed on the outer periphery of the male end when the latter is introduced into the said socket and secondly means for locking the male end in the socket, said means being intended to prevent any relative axial movement between the said pipes, these mean. s comprising a collar surrounding the c c 1 3 GB2195159A 3 4 male end, retained axially on the latter in order to be prevented from sliding towards its joining end and an outer flange provided at the end of the female socket and able to penetrate and to be locked in a recess provided in the said collar about the male end, wherein the said locking means comprise a ring having a circular opening enabling it to be engaged on the said female socket by bearing behind the said flange comprised by the end of this socket, this flange being entirely a part of revolution and the said ring comprises on its outer periphery, a succession of alternate lugs and slots able to cooperate, according to the so-called -bayonet- system with lugs - directed radially inwards-and corresponding alternate slots provided on the said collar at the entrance to its recess.

2. Coupling according to claim 1, wherein at least one of the lugs of the said ring-prefer ably the one which is highest after locking-comprises on its outer periphery a groove directed parallel to the axis of the pipes and able to be located, once locking is achieved, opposite a similar groove passing through the said collar at the level of the corresponding lug in the latter, an angular locking cotter then being able to be engaged in the housing formed by the two grooves.

3. Lockable coupling substantially as hereinbefore described with reference to the accompaning drawings.

Published 1988 at The Patent Office, State House, 66/71 High Holborn, London _WC 1 R 4TP. Further copies may be obtained from The Patent Office; Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

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