Patent GB-968092-A (GB)
Title: Improvements in or relating to load guiding devices, for example charge chutes for nuclear reactors
Inventor: GARDENER TERENCE EDWARD GOUVEN
IPC: G21C19/16
Filed: 1959-09-16
Abstract: 968,092. Fuelling reactors. BRISTOL AEROJET Ltd. Dec. 14, 1960 [Sept. 16,1959], No. 31571/59. Heading G6C. A shoot for serving reactor fuel element channels 43 comprises two co-axial casing parts 20... 22 and 28... 31 rotatable relative to one another in one direction, a fuel element guiding members 41 carried by the part 28... 31 and movable transversely to the axis of the casing parts and a tubular actuating member 82, the member 82 being connected so that when rotated in one direction it rotates the part 28... 31 and member 41 and when rotated in the opposite direction it moves the member 41 transversely to the casing axis. One-way clutches select the drive from the member 82 in dependence upon its direction of rotation, one drive serving to rotate the part 28... 31 and member 41 and another drive serving to move the member 41 transversely. The drive for moving the member 41 transversely also includes a two-way clutch (Fig. 6 not shown) controlling a reversing gear, the two positions of the clutch determining, respectively, transverse movement towards and away from, the casing axis. The clutch is moved from one position to the other by axial movement of the member 82 against a return spring. The fuel element guiding member 41 is supported by the casing 31 by a parallelogram linkage comprising upper links 44, lower links 45 and radius arms 46. The links are attached to the member 41 by pivots 47, 48 and to the casing 31 by pivot rods 49, 50 sliding in vertical slots 53, 54, the rods 49, 50 being interconnected by a link 57. Thus downward movement of the rods 49, 50 in the slots 53, 54 causes the member 41 to move transversely through an opening 40 in the casing 31. A plate 63, Fig. 4, connected to the rod 49 is connected by a pivot 62 to a link 61 fixed at its upper end to a nut 59, this nut engaging a threaded shaft 58, the shaft 58 being driven by the two-way clutch previously mentioned. Thus rotation of the actuating member 82 in the appropriate direction causes vertical movement of the nut 59 to produce transverse movement of the member 41. The shoot is adapted to be inserted through a reactor standpipe by the machine disclosed in Specification 927,359 and be supported in the standpipe by a seal plug (not shown) attached to a flange 33 on the casing part 20. The lower casing part 31 is connected to the part 30 thereabove by a sliding joint so that the weight of the part 31 and member 41 is taken by a bearing 36 carried by the part 31, the bearing having a spigot 37 engaging a channel 38 in a charge pan. The fuel element channels 43 to be serviced from a standpipe are disposed as shown in Fig. 5 and are numbered 1... 16, the channels being disposed on three circles having radii R 1 , R 2 , and R 4  and on twelve angular directions a... l. In operation the fuel element guide member 41 is moved to radius R 1  and serves in turn channels 1... 4, the member 41 then being moved to radius R 2  to serve channels 5... 12 and finally being moved to R 3  to serve channels 13... 16 The degree of transverse movement permitted to the member 41 is determined by a pre-selector mechanism comprising a plate 66 movable vertically by a shaft 67 having a threaded portion 68, a slot 69 in the plate receiving the pivot rod 49. Thus the position of the lower end 155 of the slot 69 determines the extent of the transverse movement. The shaft 67 is driven through a cam plate and gearing such that after servicing of channel 4 and the member 41 is rotated from position j to position l, the plate 66 is simultaneously lowered by the rotation of the member 82 to permit transverse movement of the member 41 to  radius R 2  by reverse rotation of the member 82, similarly, after channel 12 has been serviced and the member is rotated from position k to position a, the plate 66 is lowered further to permit transverse movement of the member 41 to radius R 3 . A sleeve 145 slidable on the member 41 is moved to locate in the chamfered mouth of the channel 43 when the pivot 49 moves into the offset end 155 of the slot 69, the slot 54 having corresponding offset portions for each radius R 1 , R 2  and R 3 . When the pivot 49 is offset a pivot 64 on the plate 63 leaves the vertical slot portion 65 in the selector plate 66 and enters a quadrant-shaped portion 156 whereby the plate 63 pivots about the pivot 49, the pivot 64 is connected to the sleeve 145 through links 147, bell crank lever 148, links 149, an upper sliding sleeve 150 and a push-pull rod 151. The sleeve 150 also controls two parts 153, 154 in the guide tube 41 for controlling the passage of gas therethrough as disclosed in Specification 968,091. The gas and fuel element passage formed by the tube 41 is continued through the remainder of the shoot by a telescopically extensible section 75 having spherical joints 73, 74 at its ends and by a section 72 in the casing part 31, the section 72 leading to a telescopic section 77 in turn leading to the tubular shaft 82 and a drive tube 34. The tube 34 is inserted into the shaft 82 from a fuel element charging machine as disclosed in Specification 968,091 and transmits the drive by splines 81. The fuel element 42 being transferred is held by a grab 157 on a cable 158 passing over groups of three rollers 160... 162, 168... 170 provided at the joints 73, 74. Shielding is provided by concrete 35, 172.