Patent GB-783265-A (GB)
Title: Improvements relating to coupling arrangements, e.g. for pipes
IPC: F16L37/34
Filed: 1955-11-07
Abstract: 783,265. Pipe &c. couplings. WURZBURGER, P. D. Nov. 7,1955 [Nov. 8, 1954], No. 31796/55. Class 99(1). A ring structure lying in an annular groove formed in one of the two surfaces of a tubular end of one of two members to be coupled together comprises a resilient split ring 100 and a number of segments 101 spaced circumferentially around the ring, the segments having projections 128 and being biassed by the ring in a radial direction so that the projections protrude through slots extending from the groove to the other of the surfaces of the tubular end. Means are provided for pushing the projections simultaneously to move the segments against the bias of the ring and for holding the structure in a disposition in which the structure cooperates with an annular shoulder on the other member, thereby coupling the two members together. As described, the locking arrangement is applied to a pipe coupling comprising coupling members B. C. Fig. 1, which, when disconnected, may be automatically sealed by spring-loaded valves, and a sleeve A. Locking structure. As shown in Figs. 8 and 9, the locking structure includes an expansible and contractible split ring 100, of spring,steel and square in cross-section, and four aluminium arcuate segments 101, L-shaped or U-shaped in cross-section, distributed about the circumference of the ring, the latter being received in channels formed in the bottoms of rabbets 120 of the segments ; each segment consists of a central portion 128 and radially shallower wing portions 129. A narrow circumferential lip 133 of the segments overhangs the outer edge of the exposed face of the ring 100, and the radial depth of the rabbets is greater than that of the ring so that the curved inwardly directed faces of the segments are located inwardly of the inner surface of the ring. To limit relative circumferential movement between the ring and segments one of the latter has a bent-in finger 142. Coupling member B. A plug 1 screw-threaded at 2 for connection to a hydraulic conduit is formed with a hexagonal section 3 over which fits the correspondingly shaped part 5 of a plate 4 for attaching the plug to a wall ; the internal screw-thread 6 receives an extension 8, and a gasket 13 is located in a chamber formed between the plug and extension. Internally of the plug is a web 15 provided with oblique passages 21 spaced about a hollow stem 16 supported by the web and having an outer surface 17 spaced from the inner wall 24 of the extension 8 to form an annular channel 19. The latter communicates with the main channel 20 of the plug via the passages 21. Formed internally of the extension 8 is a frusto-conical valve seat 25 which terminates at a circular opening 26 axially spaced from the end face 27 of the extension, and an annular groove 28 which receives a rubber 0-ring 30. A barrel-shaped valve body 32 slidable on the stem 16 is provided with a spherical surface 35 to make circular line contact with the seat 25, and an annular groove 51 for a rubber 0-ring 50 and a flat, backing washer 52 of polytetrafluoroethylene ; a spring 38 is located in a channel 39 in the stem 16 and reacts between the bottom of that channel and a flange 42 on the valve body. A portion 54 of the stem 16 having a free fit within the opening of the flange 42 provides a supplementary guide for the valve body. Lying at one end of an annular groove 102 formed in the extension 8 is a split ring 121 circular in cross-section. Coupling member C. A tubular body 60 screw-threaded at 61 for reception of a hydraulic conduit has a central passage 62 communicating with a passage 65 in a tubular stem 63 screwed into the body and having an integral head 66 immediately behind which is a series of oblique ports 71 allowing fluid communication between the passage 65 and an annular chamber 70 surrounding the stem. An 0-ring 59 lies in a channel formed in the head. The chamber is sealed against the flow of fluid through the member C by a sleeve valve 72 guided for axial movement by an internal surface 73 of the body 60 which surface is formed with an annular channel 76 accommodating a rubber 0-ring 77 and a backing ring 52. The valve 72 is biassed by a spring 80 on to a seat 87 formed on the head 66 and is provided with a radial shoulder 90 and a pilot flange 93. Adjacent the shoulder 90 is a land 91 and between the latter and the flange 93 a tapered surface portion 94. Contraction of the ring 100 of the locking structure is effected by an actuator sleeve A slidably carried on the body 60 and having a number of circumferentially spaced, axially extending ribs 119 which in the locked position fit between an equal number of ribs 110 formed on the body. As viewed in Figs. 1 and 3, the sleeve is biassed to the left by a spring 104 one end of which abuts the radial end faces of the ribs 119 whilst the other end of the spring pushes against a retaining ring 106 having a sliding fit within a bore 113 of the sleeve ; the shoulder 98 serves as a stop which determines the retracted position of the sleeve, as shown in Fig. 3. To locate and hold the ring 106 in position against a shoulder on the body 60 a split locking-ring 108 projects partially into a groove 109 formed in the body, and into a groove 95 in a flange of the ring. For the reception of the locking structure, the surface 115c, Fig. 3, of the body 60 is formed with an annular groove 99, Fig. 6, at least equal in depth to that of the structure, the radial thickness of the walls of the body 60 between the ribs 110 being less than the radial depth of the channel so that the latter forms radial slots opening into the grooves 122 between the ribs, the segments 101 thus being exposed for engagement by inclined cam surfaces 118 on the ribs 119, those surfaces being curved in planes normal to the axis of the member C, to conform to the crown of the portions 128 of the segments 101, and straight in longitudinal axial planes ; the wing portions 129 of the segments extend underneath the ribs 110. Forward of the cam surfaces 118 is a cylindrical surface 135 by which the locking structure is held captive when the sleeve is retracted. Coupling Operation. Insertion of the member B into the member C causes the end face 27 of the extension 8 to engage the shoulder 90 of the valve 72 to displace the latter from sealing engagement with the surface 87 of the head 66. The valve 32 is then engaged by the head 66 and is moved away from the seat 25, the internal passages of the members B, C thereby being placed in communication with each other; the fluid pressure in the coupling augments the force required to open the valves. In the sequential valve-opening stages of the coupling operation, the sleeve A remains in its retracted position with the locking structure in its fully expanded condition, the upper edge corners of the segments 101 of the structure being received in the angular intersections between the cam surfaces 118 and cylindrical surface 135 of the sleeve and therefore serving as detents. When the head 66 pushes the flange 42 into contact with the face 40 of the stem 16 and further telescoping of the members B, C is not possible, further force applied to the sleeve A causes the latter to advance forward on the body 60, the limit of such advancement being determined by engagement of the rear faces of the segments 101 with the shoulders 127 of the ribs 119, thereby causing contraction of the ring 100 of the locking structure into the groove 102 of the extension 8. The ring 100 bears against the ring 121 along a circular contact line. To effect separation of the members B, C, the sleeve A is retracted to allow expansion of the ring 100, the latter being disengaged from the ring 121 and the movement of the valves 32, 72 under the action of the springs 38, 80 facilitating axial separation of the members. During coupling, air trapped between the stem 16 and the head 66 by the sealing action of the 0-rings 50, 59 is vented to atmosphere through an axial bore 130 in the stem, and a passage 131 in the web 15 and section 3 of the plug 1. In a modification, the valve 32 and stem 16 are eliminated and the valve 72 is replaced by a tubular element rigidly secured to the body 60, the rings 100 and 121 being loaded by an axial force derived from compression by a surface on the element of a resilient deformable 0-ring corresponding in location and function to the ring 30. In a further modification, the body 60<SP>1</SP>, Fig. 13, of the member C<SP>1</SP> has an extension 140<SP>1</SP> provided with an internal surface 114c<SP>1</SP> which slidingly fits with the external surface 114b<SP>1</SP>, common to both the plug 1<SP>1</SP> and the extension 8<SP>1</SP>, and the internal cylindrical surface 115c<SP>1</SP> of the body, of smaller diameter than the surface 114c<SP>1</SP>, engages the complementary surface 115b<SP>1</SP> of the extension 81. The ring 100<SP>1</SP> of the locking structure is of circular crosssection, and the ring 121<SP>1</SP> lying in the groove 102 of the extension is square in cross-section. Also, the faces 123<SP>1</SP> of the ribs 119<SP>1</SP> are inclined to the axis of the member C<SP>1</SP>, the central portion 128 of the segments 101<SP>1</SP> being correspondingly inclined. In a still further modification, the plug 1<SP>11</SP>, Fig. 14, has an internal surface 18<SP>11</SP> tapering outwardly toward an end face 2211 thereof, and an external screw-thread on to which the extension 8<SP>11</SP> is screwed. To ensure correct seating of the valve 32<SP>11</SP> the latter is retained in predetermined rotative position on the stem 16<SP>11</SP> by a spring 38<SP>11</SP> the ends 4311, 44<SP>11</SP> of which are bent at right angles to lie parallel to the axis of the coupling and are respectively located in a socket 45<SP>11</SP> at the base of the channel 3911 and a hole 4611 in the flange 4211 of the valve. The sleeve All is formed with a single bore 103<SP>11</SP> within whic