Patent GB-834229-A (GB)
Title: Improvements in pipe couplings
Inventor: SURTEES BENJAMIN JOHN
IPC: F16L37/248
Filed: 1956-02-06
Abstract: 834,229. Pipe couplings. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Feb. 14, 1957 [Feb. 6, 1956], No. 3602/56. Class 99(1). In a coupling for connecting together components of a fluid delivery system and comprising two mating half couplings which can be connected together and locked in such position, each half coupling A, B, is provided with a valve and a valve opening and closing mechanism which must be operated to move the valve into the closed or fluid-sealing position thereof and into contact with the valve of the other half coupling before the half couplings can be unlocked; such mechanism can maintain the valve in the closed or fluid-sealing position until the coupling together of two half couplings is effected whereupon the valves can be moved apart. As shown, the identical halves A, B of the coupling are connected by a bayonet joint 1 close contact being made between the mating end surfaces of the halves. Each half of the coupling has an externally screw-threaded, tubular connector 3 provided with a recess for a sealing ring 5 of polyethylene or polytetrafluoro-ethylene and a flange 4 to which one end of a flexible bellows 20 is secured, the other end of the bellows being attached to a nut 16 having an external screw-thread of opposite pitch to that of the screw-thread on the connector 3. A sleeve 21, split longitudinally and held together by clips 23, has at each end an internal screw-thread cooperating respectively with the screw-threads on the connector and nut. A conical valve seat 6 on the connector co-operates with a valve head 7, coated with flexible sealing material, the stem 9 of the valve being held centrally in guides 10, 11 perforated to allow the passage of fluid and rigidly connected by a tube 12. The stem is fixed to the guide 11 which is clamped between the nut 16 and an adaptor 17, and the guide 10 has peripheral slots slidable on splines 14 provided on the connector. Rotation of the sleeve 21 on each coupling part A, B causes the nut 16 and valve 8 to move axially relative to the connector 3 to open or close the valve. Similar spring-loaded locks are provided on each coupling half to prevent the coupling from being disconnected when the valves are open and these each comprise a pivoted trigger 24 the head 26 of which engages in a slot 27 so that relative rotation between the halves A, B is prevented and the bayonet grip 1 cannot be released. In each of the sleeves 21 is a circular groove 28 which when the valves are closed, lie beneath projections 29 on the trigger levers 30 and in these positions of the grooves the levers can be operated to permit release of the coupling ; with the valves in the open positions thereof the ridges 31 are beneath the projections 29 and prevent operation of the levers. In a modification, the connectors 32, 33 are located relative to each other by dowel pins 36 and sealing rings 35 are located in circular dove-tail shaped grooves in the contact faces of the connectors. Toggle-type fasteners 40, 40a each have a clip 42 provided with a sloping end 45 which is brought into contact with sloping projections on the sleeve 47 ; the clip has claws 48 which engage in an annular channel 49 in the sleeve when the sleeves 47, 50 are oppositely rotated to open the valves.