Patent GB-998086-A (GB)
Title: A self locking coupling assembly
Inventor: BELLINGER RONALD
IPC: F16J13/02
Filed: 1960-10-05
Abstract: 998,086. Stud and socket fastenings. STRACHAN & HENSHAW Ltd. Sept. 29, 1961 [Oct. 5, 1960], No. 34216/60. Heading E2B. [Also in Division G6] A self locking coupling assembly includes two telescopically arranged separable bodies 11, 17, having a common longitudinal axis, each body being provided with an inclined annular reaction surface 29, 37, said reaction surfaces facing each other, and at least one retractable locking member 31 adapted to be engaged between the reaction surfaces or to be withdrawn to a disengaged position, wherein the or each locking member has a single longitudinal axis and two end faces which are respectively engageable with the reaction surfaces. As shown the two bodies are part of a nuclear reactor, the body 11 being an annular head which is secured to the upper end of a stand pipe 12 by means of bolts (not shown). The bottom end portion of the body 17 is a sliding fit in a sleeve 19, sealing rings 26 being disposed between the adjacent faces of the end portion and the sleeve. The body 17 has a neck 28 and disposed around this neck is an annular element 18 made in two or more portions. The element 18 is a sliding fit on the neck 28 and is also an easy fit within the head 11. A plurality of the locking members 31 are provided and these are in the form of hardened pins slidably mounted in the element 18, the axis of each pin being at right angles to the surface 29 on the body 17. The bottom end 34 of each pin rests upon the surface 29 when the element 18 is in its lowermost position and the top end of each pin projects beyond the outer circumferential surface of the element 18. The top end of each pin is convex and is part of a spherical surface and the surface 37 on the head 11 is concave and either part is a spherical surface or part of a conical surface; the surface 29 is convex and is also either part of a spherical surface or part of a conical surface, the centre of curvature of each surface 29 and 37 being at the junction of the axes of the pins and the axis 30 of the two concentric members. The lowest end of each pin can be concave and part of a spherical surface. The surface 37 is formed on the inner face of a recess 36 in the head 11 and when pressure in the reactor tends to force the body 17 outwardly each pin engages the surfaces 29 and 37. When it is desired to raise the body 17 axially relative to the stand pipe, rods 38 connected to a lifting device are passed through holes 39 in the flange 27 of the body 17 and are screw threaded into the element 18. The element 18 is then raised axially relative to the body 17 and the pins slide towards the axis 30 along the surfaces 29, 37 until the upper ends of the pins are withdrawn into the element 18 sufficiently for the body 17 to be withdrawn from the head 11. In a modification the surface 29 is formed with a step which prevents the element 18 being lifted while the body 17 is being thrust upwardly by pressure in the reactor. In a further modification the body 17 is made a different shape and the sleeve 19 is omitted so that the element 18 can be a one-piece member.