Patent GB-1187741-A (GB)
Title: Irradiation Apparatus
IPC: G21K5/02
Filed: 1968-05-03
Abstract: 1,187,741. Conveyer systems. SULZER BROS Ltd. 3 May, 1968 [3 May, 1967], No. 21041/68. Heading B7L. [Also in Division H5] An irradiation apparatus comprises a source of radiation past which individual load carriers in close proximity to each other are conveyed on at least one pair of mutually parallel tracks the tracks having a common horizontal conveying plane, a first length of closed loop chain conveyer being positioned adjacent one of the pair of tracks, a second length of closed loop chain conveyer adjacent the other of the pair, a loop of track interconnecting the pair of tracks and -adjacent the loop of track-a third length of closed loop chain conveyer arranged to travel faster than the first and second loops of conveyer, the third length having load-entraining means so as to engage the loads and transfer them from the first track of the pair along the loop track to the second track of the pair. The load entraining means may comprise dogs secured to the third length of chain conveyer. As shown in Fig. 1 two pairs of tracks 5 and 6 are positioned in a chamber 2 so as to run adjacent the elongated source 4, the paths of the slow moving conveyer chains being shown in dashed line. The tracks 5, and 6 of the slow moving conveyers are partly overlapped by one track of the chain conveyer 7 which connects a loading and unloading and transfer station 8 to the chamber 2 by means of passage 3. The chains of conveyer 7 run at approx. one and a half times the speed of the slow conveyers. At the left hand end as depicted in the figure the tracks 5 and 6 of the slow conveyers are overlapped by the tracks of two turning conveyers 9 and 10, the chains of which also run at one and a half times the speed of the slow conveyers. At the right hand end the loads are transferred by a loop 11 of the fast conveyer 7. A parallel motion mechanism 12 is provided adjacent the loop 11. The chain conveyer system is operated by a motor preferably electric, through a sprokcet wheel 16, the various chains being interlinked by transmissions. When the source 4 is radio-active, e.g. an array of Co 60 rods, the chamber is surrounded by biological shielding 1, and the motor 15 is positioned outside the shielding to facilitate servicing. Because of the parallel displacement of the loads in loop 11, the individual load carriers are rotated 180 degrees about the axis passing vertically through them relative to their direction of movement at least once on their way past the radiation source. As shown in Fig. 2, the loads are supported on indivudual carriers 20, each of which runs on rollers 33 on T-section track 32 suspended by arm 31 on T-section frame 30. The rollers are mounted on a traveller 36, the upper end of which forms a projection 37, the lower end 38 being a downwardly projecting swivel pin which on a shoulder 41 supports a ball bearing 40 on which rests a sleeve 39 to which there is attached by screws 43 a surrounding sleeve 42 which forms a part of the load supporting box 44. The load is maintained in a given orientation by a lever actuated spring- loaded pin carried by the box 44 and co-operating with a slot cut in swivel pin 38 (Fig. 4, not shown). The lever system is actuated by the parallel motion mechanism 12 (Fig. 3, not shown) to permit the load to rotate through 180 degrees on swivel pin 38 on its passage round the source. The fast conveyer chain 7 and the slow chain 5 run in two guide sections 80, 81 attached to the frame 30. Curved catches 83 are attached to the outer links of the chain 7 at suitable intervals and the central links of the chain 5 carry straight catches 84 at intervals corresponding to the length of the supporting boxes. The chain 5 runs on the chain wheel 85 shown in section which is connected by screws 86 and spacer 87 to a transmission wheel 88. The outer rings of a ball bearing 90 are clamped between the spacer 87 and the transmission wheel 88, the spacer 87 and a shoulder 89; the inner rings being supported on a pin 91 which is welded to a cross member 92 which connects the two parallel sections of the frame 30. The chain 7 runs round a chain wheel 93 which is connected by a spacer 94 to a transmission wheel 95 (Fig. 5, not shown) concealed behind wheel 88. Wheels 95 and 88 are connected by chain 96 and have sizes such that the chain 5 is driven by the chain 7 with a speed reduction in the ratio 2 : 3. The spacing between catches 83 and 84 on chains 7 and 5 should be arranged so that the pin 37 on traveller 36 is not caught between two of them at the transfer points.