Patent GB-840471-A (GB)
Title: Improvements in or relating to plugs or closures for conduits or orifices
Inventor: ROBERTS HENRY
IPC: F16L55/11
Filed: 1957-12-20
Abstract: 840,471. Closures for conduits &c. FLIGHT REFUELLING Ltd. Jan. 21, 1959 [Dec. 20, 1957], No. 39702/57. Class 99(1). In a plug or closure comprising a body 10 adapted to make a fluid-tight joint with a peripheral surface 37 in a conduit, orifice or like opening, main radially movable locking members 16 in the body adapted to enter a circumferential groove 39 in the conduit, and a member 17 movable axially in the body between positions in which it respectively holds the members 16 in extended positions and allows them to retract and release the plug, secondary radially movable locking members 26 for locking the member 17 to the body when the members 16 are in locking position are urged to their locking position by a ramp surface on a sleeve 27 axially movable relative to the member 17 and biassed by spring means 29 to effect locking action of the members 26. As shown, the body 10 has spaced walls 11, 12 connected by a wall 13, the inner wall being formed with a flange 14, and the wall 12 having radial, tapered holes 15 in which are located balls 16. An annular plunger 17 located between the walls 11, 12 and urged towards the wall 13 by springs 22 is provided with a skirt 23 formed with radial holes 25 housing balls 26 movable into a circumferential groove 24 in the flange 14 to lock the body and plunger against relative axial movement. Slidable externally on the skirt 23 and against the action of springs 29 is a sleeve 27 having a circumferential groove 28. In positioning the plug 10, the latter is suspended by means engaging the skirt 23 and lowered until the shoulder 38 of the plug seats on the frustoconical shoulder 37 of the conduit 33 and the plunger 17 is allowed to move downwardly relative to the plug to displace the balls 16 outwardly into the groove 39, the balls 26 being then positioned opposite the groove 24. Release of the sleeve 27 allows the latter to move upwardly and force the balls 26 into the groove 24 to lock the plunger in position and thereby prevent the balls 16 moving to release the plug from the conduit. For manipulation of the plug, there is provided a pair of relatively slidable co-axial tubes 41, 42, the tube 42 which passes freely over the rim 43 of the skirt 23 to engage the sleeve 27 having holes 44 therein and containing balls 45 and the tube being provided with a circumferential groove 46. The tubes are disposed around the skirt 23 and by pressing the sleeve 27 downwardly by means of the tube 42 and moving the tube 41 downwardly until the groove 46 is below the holes 44, the balls 45 are displaced inwardly to engage beneath the rim 43 ; the plug can then be inserted into the conduit and when in position released by raising the outer tube 41 relative to the tube 42 and then raising both tubes together. The plug may have an open, as shown, or closed central portion, and may be employed for laterally opening passages, or downwardly opening passages ; in the latter case, the plugger 17 may be modified to move downwardly to the locking position thereof and by its own weight.