GB2219370A - Readily disconnectible pipe coupling - Google Patents

Abstract

The invention relates to a quick-release coupling for use to reduce spillage where pipes are to be disconnected without first being drained. The coupling comprises two members (2, 34) each defining a through-flow passage for liquid when coupled and closing the passage simultaneously in each member by means of a valve head portion (22, 58) seating against a valve seat portion (26, 60 respectively). The valve head portion (22) in the first coupling member (2) is spring-biased into its closed position and held open by the projection of the opened valve head portion (58) from the second coupling member (34) into the bore of the first coupling member (2). Relative movement between the two members (2, 34) causes a cam arrangement (52, 54) to operate to withdraw the valve head (58) into its closed condition within the second coupling member (34) so that the first valve head (22) returns to its closed condition under the influence of the spring (24). <IMAGE>

Description

PIPE COUPLING The invention is concerned with improvements in or relating to pipe couplings, particularly but not exclusively, for use in manual connection and disconnection of liquid delivery pipes.

There are many circumstances in which it is necessary to disconnect a flow pipe coupling when it is impractical to empty the pipe before disconnection. Many devices have been proposed for closing over each of the two coupled pipe ends prior to disconnection but there has always been a certain amount of spillage. Moreover, where care is necessary in the closure of the pipe ends to reduce the amount of spillage which would otherwise occur, hasty handling may result in an appreciable loss of liquid.

It is an object of the present invention to provide a pipe coupling which may be quickly and easily disconnected with a minimum risk of spillage.

The invention therefore provides a pipe coupling comprising two coupling members each adapted to receive one of two pipe ends to be connected together to provide a through-flow of liquid, a first coupling member comprising a housing defining a passage for liquid, support means spanning said passage to permit a flow of liquid therepast, first valve means comprising a valve portion mounted in said support means for axial movement with respect to the housing between an open position in which liquid may flow through the coupling member and a closed position in which a head portion of the valve portion seats on a valve seat surface on the housing and a second coupling member comprising a casing, an end portion of which is adapted to engage an end portion of said housing in a quick-release connection, said casing enclosing a second valve means comprising a valve portion mounted for axial movement with respect to the casing, said axial movement being brought about by a cam device operating to move the valve portion between an open position in which liquid may flow through a passage within the casing and a closed position in which a head portion of the second valve portion seats on a valve seat surface on the casing, said cam device causing movement between said positions concomitant with the relative movement between the two coupling members occurring during the operation of the quick-release connection therebetween, wherein the first valve head directly abuts the second valve head when the coupling members are connected, said first valve portion being spring biased into its closed condition and forced into its open position by the force exerted thereon by the second valve member in its open position, release of the quick-release connection resulting in cam-controlled withdrawal of the second valve portion into its closed position allowing the first valve portion to return to its closed position.

Advantageously, the quick-release connection comprises a bayonet-type connection device, said relative movement between the coupling members being at least in part rotary about the longitudinal central axis of the coupling.

There will now be disclosed an example of a pipe coupling according to the invention. It will be understood that the description which is to be read with reference to the drawings, is given by way of example only and not by way of limitation.

In the drawings: Figure 1 is a side view, partly in section and partly broken away for clarity, of a first coupling member; Figure 2 is a view on line Il-Il of Figure 1, excluding a housing of said first coupling member; Figure 3 is an end view of the first coupling member; Figure 4 is a side view, partly in section and partly broken away for clarity, of a second coupling member; Figure 5 is a view of a valve portion of the second coupling member viewed at 900 from Figure 4; Figure 6 is a diagrammatic representation of a cam track of said second coupling member; Figure 7 is an inner end view of the second coupling member; and Figure 8 is a fragmentary view, to an enlarged scale of confronting portions of the two coupling members in use.

The pipe coupling comprises a first pipe coupling member indicated at 2 in Figure 1. The coupling member 2 comprising a housing 4 having an internal shoulder 6 against which is received a disc-like spider 8 (Figure 2) having through-flow apertures 10. The spider 8 is retained firmly in place by an annular end cap 12 which is also internally threaded at 14 to receive the connector member of a liquid delivery pipe (not shown).

The spider 8 is provided with a boss 16 having an aperture 18 through which passes for free axial movement a valve stem 20 of a first valve means. The stem 20 supports a valve head 22 and a compression spring 24 is arranged between the boss 16 and the head 22 to bias the latter into a position spaced from the spider 8 and in which the valve head 22 seats against a seat surface 26 provided on the inner wall of the housing 4. The presence of an O-ring 27 ensures a liquid tight seal.

A deep groove 28 provided in an external wall surface of the housing 4 is provided for purposes which will be explained hereinafter, together with a plurality (in the present example three) of notched recesses 30,best shown in Fig. 3, formed in a flange-like portion 32 of the housing 4 formed by the groove 28.

Figure 4.shows a second pipe coupling member 34, comprising a casing 36 to which is co-axially secured a sleeve-like extension 38 having an internal flange 40 extending around a major portion of its circumference (see Figure 7) to leave a gap 42.

As viewed in Figure 4, there is provided below the flange 40, captive but capable of rotation, a valve seat ring 44 having an exterior circumferential flange 46 to which is welded an upstanding lug 48, projecting through the above described gap 42 of the flange 40, (see also Figure 8) into one of the recesses 30.

The valve seat ring 44 is adapted to rotate with respect to the flange 40 and an upper portion of a sleeve 50 secured by a peg 51 against rotation relative to the casing 36. The sleeve 50 is provided with two complimentary cam slots 52, the track of which is shown in projected form in Figure 6.

Received in the cam slots 52 at opposite sides of the sleeve 50 are cam following rollers 54 provided on a plate member 56 (see also Figure 5). At an upper portion of the plate 56 as viewed in the Figures, is secured a valve head 58 adapted to seat in a closed position against a seat surface 60 of the valve seat ring 44.

Side edge portions of the plate 56 are received in notches 62 formed at diametrically opposite regions of a ridge portion 64 formed in the seat ring 44, so that, as the ring 44 rotates, rotary movement is imparted to the plate 56, the rollers ride along the cam track 52 and the valve head 58 is raised or lowered between an open and closed condition.

The two coupling members 2 and 34, are connected together as follows: With both valve heads 22 and 58, seated in the closed positions, the two members are brought together so that three roller members 66 provided at spaced locations within the sleeve portion 38 of the member enter the three notched recesses 30 of member 2 by the same action, the lug 48 is received in the gap 40 at a first end thereof.

Since the valve head is in its closed condition it will be appreciated that the plate 56 is in its lowest position with the rollers 54 at the lower end A of the cam track 52. The two heads 22 and 58 are however in contact, with confronting surfaces 68 and 70 touching congruently.

As the two coupling members are then rotated manually with respect to one another, the roller members 66 move along the groove 28 in the manner of a bayonet-type connector to prevent axial movement between the two members 2 and 34. However, as this occurs, because the lug 48 is engaged in one of the three recesses 30, the relative rotary movement causes the lug to compel the valve seat ring 44 to rotate relative to the casing 4 and the sleeve 50. This results in the rollers 54 rising in the tracks 52 towards the upper end B. Thus the plate 56 and the valve head 58 are raised in a helically twisting movement. The positive raising motion of the head 58 then compels the head 22 to be forced back into the housing 4 against the influence of the spring 24.

Thus, the relative rotary movement between the two coupling members has moved the head 58 from its closed position to its open position and in doing so, has forced the head 22 from its closed position to its open position. Liquid may now flow through the coupling members.

The disconnection of the coupling members is achieved by relative rotary movement therebetween in the reverse direction, which because of the lug 48 causes the cam rollers 54 to travel back along the track 52 to point A.

As the valve head 58 retracts towards its closed position, so the spring 24 causes the head 22 to follow the head 58 and therefore head 22 moves to its own closed position.

Since both coupling members are now in a valve closed condition, they may then be pulled apart to complete the bayonet-type action.

Various modifications may be made within the scope of the invention as defined in the following claims.

Claims (5)

CLAIMS:

1. A pipe coupling comprising two coupling members two coupling members each adapted to receive one of two pipe ends to be connected together to provide a through-flow of liquid, a first coupling member comprising a housing defining a passage for liquid, support means spanning said passage to permit a flow of liquid therepast, first valve means comprising a valve portion mounted in said support means for axial movement with respect to the housing between an open position in which liquid may flow through the coupling member and a closed position in which a head portion of the valve portion seats on a valve seat surface on the housing and a second coupling member comprising a casing, an end portion of which is adapted to engage an end portion of said housing in a quick-release connection, said casing enclosing a second valve means comprising a valve portion mounted for axial movement with respect to the casing, said axial movement being brought about by a cam device operating to move the valve portion between an open position in which liquid may flow through a passage within the casing and a closed position in which a head portion of the second valve portion seats on a valve seat surface on the casing, said cam device causing movement between said positions concomitant with the relative movement between the two coupling members occurring during the operation of the quick-release connection therebetween, wherein the first valve head directly abuts the second valve head when the coupling members are connected, said first valve portion being spring biased into its closed condition and forced into its open position by the force exerted thereon by the second valve member in its open position, release of the quick-release connection resulting in cam-controlled withdrawal of the second valve portion into its closed position allowing the first valve portion to return to its closed position.

2. A coupling as claimed in claim 1, wherein the quick-release connection comprises a bayonet-type connection device, said relative movement between the coupling members being at least in part rotary about the longitudinal centre axis of the coupling.

3. A coupling as claimed in claim 2 wherein the second valve head portion and its associated valve seat portion are arranged for solely axial movement relative to each other, and together are capable of rotation with respect to the casing of said second member, said valve seat portion being provided with a projection adapted, when the two couplings are united, to engage a recess formed in the first coupling member so that said relative movement between the two coupling members causes the valve seat portion to rotate relative to the casing of the second member and relative to a sleeve secured to said casing, said sleeve including a cam track arrangement adapted to receive cam following devices mounted upon the second valve head portion to bring about said axial movement between the valve head portion and the valve seat portion.

4. A coupling as claimed in claim 3 wherein the second valve head portion includes a plate received at least substantially within said sleeve and having side edge portions adapted to be sliding received in grooves formed in the valve seat portion parallel with the axis of the valve head.

5. A pipe coupling comprising two coupling members each adapted to receive one of two pipe ends constructed and arranged substantially as hereinbefore described with reference to and as shown in the drawings.