Patent GB-1432732-A (GB)
Title: Hoist for use with nuclear reactors
IPC: G21C19/16
Filed: 1974-02-18
Abstract: 1432732 Hoists FRIED KRUPP GmbH 18 Feb 1974 [19 Feb 1973] 7315/74 Heading B8H A hoist for lifting and lowering fuel elements and rods for use in a nuclear reactor comprises a trolley 1, a hollow guide mast 2 which is mounted for rotation about a vertical axis 4 relative to the trolley 1, a hollow body 13 which is vertically displaceable relative to the mast 2 by means of a winch 7 which is coupled by means of cables 8 to the body 13 and a housing 17 located within the body 13 on which pairs of fuel elements head engaging members 23 are mounted (only one member 23 being shown) such that on raising the hollow body 13 the abutment of flanges 22 thereon with flanges 21 on the housing 17 causes the latter to be raised along with the body 13, and when the housing 17 is placed on a fuel element head 36 the hollow body 13 may move down relative to the housing 17 by an amount shown in N. The members 23 pivot about respective axes 24 between their operative position shown in which they each engage an apertured extension piece 35 on the fuel element head 36 and their inoperative position illustrated in Fig. 3 (not shown) by the action of a piston 31 located in a cylinder 32, as a piston-rod 30 which is coupled to the piston 31 is also coupled to a crossmember 29 from which rods 27 extend to pivotal connections on the members 23. A spring 34 which is disposed about an extension 33 of the piston-rod 30 biases the piston 31 upwardly and thus the members 23 to their operative position. Also mounted on the housing 17 is a mechanism for engaging with a sleeve 47 attached to a rod head 48 on the form of a plate to which the rods 49 are attached. This mechanism comprises a spigot (46) mounted at the lower end of a pneumatic cylinder 45 which is mounted on a platform 28 of the housing 17, Fig. 2 (not shown), the spigot (46) in use entering a sleeve 47 which extends upwardly from the rod head 48. Balls (50) are situated in radial holes of the spigot (46) and an annular groove (51) in the sleeve 47 is disposed opposite those holes. The cylinder 45 contains a piston 54 connected to a piston-rod (53) which is slidable in a central bore in the spigot 46 and has an annular groove, and on downward movement of the piston 54 under the force of compressed air the part of the piston-rod above the annular groove forces the balls (50) into annular grooves (51) in the sleeve 47, thus attaching the spigot (46) to the sleeve 47, Fig. 3 (not shown). Also shown in Fig. 1 is a piston 70 located in the sleeve 47 which, on moving downwards relative to the sleeve, causes the rod head 48 to become disengaged from the fuel element head 36. In Figs. 4-6 (not shown) there is shown a locking mechanism by means of which the members 23 can be held in either an open or closed (operative) condition. The locking mechanism comprises a sector (87) which is pivotally mounted on the flange 21 of the housing 17, the sector (87) being pivotally attached by a tie rod (90) and bell-crank (91) to the cross member 29 at the bottom of the piston rod 30 and having recesses (88, 89) formed therein which are separately engageable with a projection (86) on the flange 22 of the hollow body 13. A similar locking mechanism (not shown) is provided for maintaining the connection between the rod head 48 and the gripper housing 17.