Patent GB-695236-A (GB)
Title: Improvements in or relating to refrigerating apparatus
Inventor: MACKENZIE KENNETH GORDON
IPC: F25D31/00
Filed: 1951-05-10
Abstract: 695,236. Refrigerating. BIRD'S EYE (HOLDINGS), Ltd. May 9, 1952 [May 10, 1951 ], No. 11060/51. Class 29. In refrigerating apparatus of the type comprising a vertical stack of refrigerating plates 3 movable away from one another to receive the foodstuffs to be frozen between them, and towards one another to engage the foodstuffs during freezing, the stack is mounted for vertical movement in a casing 1 with a horizontal loading slot 41 in the wall, so that the freezing spaces between the plates may be successively aligned with the slot. Movable hooks 7 prevent the movement of any particular plate past the slot to enlarge the freezing space for insertion of the trays 44. The plates are guided by angle irons 59 at each corner and the bottom plate 14 of the stack is fixed, to a platform 4 supported by four wire ropes 2 connected over pulleys 21 to the piston of a hydraulic cylinder 9 mounted on the top of the casing. Stops 39, 40 limit the upward movement of the stack. The top platform 5 of the stack is connected to the bottom platform 4 by four hydraulic cylinders 6 at the corners to which oil is supplied by a flexible connection 28 and branch pipe 23, the oil passing down the hollow piston rods 29 and through openings 29a to the tops of the piston 30 to force the plates 3 together. Each plate 3 is connected by flexible pipes 10a, 11a to telescopic refrigerant supply and discharge headers 10, 11 carried by platform 4. The hooks 7 are carried by levers 16 on shafts 8 supported in bearings 42 at each side of the casing and operated together by an external lever. The hooks are arranged adjacent to but clear of the horizontal feed slot 41 and an outlet slot 49 on the opposite side of the casing, the slots being closable by doors 47, 52. In use the stack is raised, the shafts 8 turned to bring the hooks 7 into the vertical position shown and the oil pressure released to allow the stack to descend. The pressure in the hydraulic cylinders 6 is also released. Notches in the bottom plate 14 allow this plate to pass the hooks but the next plate 13 is held by the hooks together with the plates above it, and when the continued descent of the bottom plate and platform 4 widens the freezing space 12 between the plates 13, 14 sufficiently to allow insertion of the tray 44 oil flow from the cylinder 9 is stopped to arrest the descent. A tray fed by a conveyer 45 is then pushed into the freezing space, pushing before it a frozen tray 44 on to a delivery conveyer 51. The shafts 8 are then rotated to lower the hooks 7 which disengage and are retracted by springs 15 when the weight of the plate 13 and stack is taken by the foodstuffs in the tray. Oil pressure is now applied to the cylinders 6 to press the plates together compressing the foodstuffs and bringing the next plate 17 into position to be engaged by the hooks 7, and the operation is repeated. When all the freezing spaces have been filled the doors 47, 52 may be closed, or, for continuous working, the intervals between successive insertions of trays are so timed as to ensure complete freezing of the first tray by the time the last tray has been lowered so that the stack can be raised at once and the filling operation continued, pushing the frozen trays on to the conveyer 51. Instead of beginning with the bottom space the procedure can be reversed and the successive spaces loaded beginning with the top space, by suitable modification of the hook mechanism 7, 16. Specification 588,826 is referred to in the Provisonal Specification.