Patent GB-856820-A (GB)
Title: Improvements in or relating to apparatus for transporting or transferring foundry moulds from one conveyor to another
IPC: B22D33/02
Filed: 1957-06-06
Abstract: 856,820. Casting metals. BUHRER, E. June 6, 1957 [June 6, 1956], No. 18105/57. Class 83 (1). [Also in Group XXX] Apparatus for transferring foundry moulds from a feed conveyer to a delivery conveyer, or for transforming copes from a feed conveyer and depositing them upon drags on a delivery conveyer to close moulds, consists of a number of clamping members movable around a closed path by endless chains to which they are connected, each clamping member being guided relatively to the chains for movement vertically by a lifting-device attached to the chains. As shown, copes 29 are transferred from a conveyer A (see Group XXX) on to the tops of corresponding drags 29 carried by a series of trucks 28 by three clamping and lifting assemblies C mounted between a pair of endless chains 9, 12, Fig. 3, running in superposed horizontal planes around sprockets journalled in plates 5 and 108 carried by a stationary column 2. Each clamping and lifting assembly comprises a cylinder 35, Figs. 4 and 5, which carries at its upper end a guide frame. Lugs 33 and 34 are provided on the cylinder and guide frame respectively for attaching the assembly to the chains. A piston 42 in the cylinder has a support 36 for the clamping member mounted on it. Arms 122 secured to the support 36 engage guide-tracks 123 on the guide frame. A gripper frame 81 of U-shape is resiliently carried by the support 36 by means of two sets of links 124 and 125 connected as toggles between the frame and the support and spring-urged to the positions shown. The frame 81 can by this means adjust itself in any direction in the horizontal plane relative to the support 36. The frame 81 carries two pneumatically-operated gripper devices 84 constructed as described in Specification 731,984 for engaging the ends of the copes or drags. The cylinder 35 and guide frame assembly is guided on tracks 114 and 118 formed by the edges of plates 5 and 108 by rollers 113 and 117, respectively, the latter being carried by a lever 119 biased towards the guidetrack by an enclosed spring 121. The assembly is supported in the vertical direction by a roller 37 running on the plate 5. In addition, the cylinder 35 is provided with arms 72, 73 carrying rollers 115, 116 which respectively engage lower and upper guide-tracks 40, 39, Fig. 3, each of which has alternate flat and curved portions designed to guide the assembly smoothly around the axes of the chain sprockets whilst holding them against rotation about a vertical axis during their passage between these axes. The chains 9, 12 are driven by a shaft 6 extening between the sprockets at one end of the plates 5 and 108, shaft 6 being connected through bevel gearing 19, 20, a gear-box 18 and a chain 16 with a main drive-shaft 14. Further gearing 21-23 connects the shaft 6 with a tube 24 journalled within the column 2 and carrying sets of conduits leading through flexible connections from the top of the tube to the cylinders 35 and 84. Each set comprises conduits 3, 31 and 4. Conduits 4 lead to the cylinders 84 and conduits 3 lead to the bases of the cylinders 35 (Fig. 10). Conduits 3<1> lead to compensating cylinders 48, Fig. 10, formed within the pistons 42 of the cylinders 35 and adapted to be brought into operation when a mould 29 is being supported by the gripper frame 81 so as to compensate for the difference in weight of the frame 81 when empty and when supporting a mould. A piston 47 in each cylinder 48 is supported from the base of the main cylinder 35 by a piston-rod 46, a bore passing through the piston and rod to connect the conduit 3<1> with the space 85 above the piston 47. A further bore 44 is provided in the piston-rod 46 to connect the space 45 below the piston 47 to atmosphere. Air is supplied from a supply conduit 110 to the respective cylinders 35, 48 and 84 at the appropriate times to cause each lifting and clamping assembly in turn to pick up a mould from the conveyer A and deposit it on a drag carried by a truck 28 by a slide-valve assembly comprising a slide-valve 109 for each set of conduits 3, 3<1> and 4, the slide-valves being mounted on a disc 25 at the base of the rotating tube 24 for operation by a stationary cam-track 139, Fig. 10. Each conduit 3<1> is connected with the conduit 4 of following lifting and clamping assembly so that it is only necessary to have two sets of passageways in each slide-valve. The operation of the slide-valves is such that each pair of gripper cylinders operates to grip a mould on conveyer A and release it on a truck 28 and each cylinder 35 lifts the gripper frame 81 after the latter is engaged with a mould and is cut off from the air supply at a point in advance of the discharge point at which point the compensating cylinder 48 takes over to allow gentle lowering of the frame 81 under the weight of the mould. To ensure smooth lifting and depositing of the moulds each piston 42 includes a dashpot formed by a cylinder 50 in which is slidable a piston 51 mounted on the lower end of a rod 52 slidable in the upper part of the guide frame. The upper end of rod 52 is secured to a guidepiece 126, Fig. 5, which is vertically slidable on a guide-rod 127 and includes an abutment 129. During raising of the frame 81 the cylinder 50 and piston 51 move together until the guidepiece 126 abuts a collar on the end of rod 127 whereupon the upward movement is damped by oil in the space 88 below piston 51 being forced through an opening 90 communicating with a reservoir 53. During lowering of the frame 81 the cylinder 50 and piston 51 again move together until the abutment 129 contacts either a plate 137 or a removable stop-pin 130. The stop-pin 130 is swung out of the way if the apparatus is being used merely to transfer drags from the conveyer A to the trucks 28 but is placed in operative position if copes on conveyer A are to be deposited upon drags already on the trucks 28 to initiate damping at an earlier stage. Upon contact of the abutment 129 with either the plate 137 or the pin 130 oil in the space 89 above piston 51 is forced through openings 140 and 54 of progressively-decreasing size into the reservoir 53. Free passage of oil from the reservoir into the space 88 is ensured by the provision of a check-valve 55 at the lower end of cylinder 50 and another check-valve 56 at the upper end of cylinder 50 performs the same function during raising of the frame 81. A guide-pin 86 carried by the guide frame enters a hole 87 in the frame 81 when the latter is in raised position. In a modification, Fig. 16, the frame 81 is mounted on a horizontal pivot by means of ball-bearings (not shown) so that it can be turned through a right-angle to perform a finishing operation on the mould. This turning of the frame 81 is effected by a pneumatic cylinder 146 whose piston-rod 147 is connected at 153 to an arm 148 secured to the frame 81. The cylinder 146 is pivotally mounted at 151 and has associated with it a damping cylinder 157 whose piston-rod 154 is actuated towards the ends of the movement of the frame 81 by the upper end of a link 152 mounted on the pivot 153 engaging collars 155, 156 on the rod 154.