Patent GB-1453517-A (GB)
Title: Automatic recipro-finishing machine
IPC: B24B31/00
Filed: 1974-01-21
Abstract: 1453517 Abrading SHIKISHIMA TIPTON KK 21 Jan 1974 [19 Jan 1973] 02829/74 Heading B3D An automatic recipro-finishing machine comprises a trough containing, in use, an abrasive medium, gripping means disposed above the trough for gripping a workpiece or workpiece holder, means for moving the trough upwardly relative to the workpiece whereby the workpiece is, in use, located inside the trough, means for finishing surfaces of the workpiece by imparting a reciprocating movement to the workpiece by the gripping means inside the trough, means for stopping the gripping means in the same predetermined position at the end of each finishing operation, means for conveying workpieces to and from the gripping means, and control means for controlling movement of the workpiece and the operation of all the means in accordance with a predetermined sequence.  The machine has four uprights 1a ... 1d which support a horizontal member 2 and adjacent the front uprights are a table 3 and a pair of bases 4a, 4b for rails 5a, 5b. A workpiece carrier 6 is movable along the rails by a fluid cylinder 8, the rod of which carries a pinion disposed between racks on the table and carrier. Retainers 15a, 15b on the carrier receive a holder 16 for workpieces 17, such as automobile bumpers. The carrier is movable by the cylinder 8 along extensions 20a, 20b of the rails into the finishing apparatus, the extensions being one each side and above a trough 21 containing abrasive media which may be granular, globular, cylindrical or triangular and comprise chips bonded in inorganic or organic binders, sintered chips with fine-grained alumina and silica, or organic grains such as chestnut shells and cone cores bonded with abrasive media. The horizontal member 2 carries frames 23a, 23b for fluid cylinders 24a, 24b having rods 25a, 25b connected to brackets 22a, 22b on the trough for raising and lowering the trough, the carrier also being raised if it is on the rails 20a, 20b. A horizontal frame 26 is secured to the uprights 1a, 1b and has a pair of traverse guides 27a, 27b engaged by guide rollers 29a ... 29d on an arm 28 reciprocated by a rod 36 driven by a disc 37 from a motor 38. The arm 28 carries a cylinder 34 operable to rock gripper arms 32a ... 32d about pivots and grip the workpiece holder 16. At the commencement of a cycle of operations, the workpieces 17 are located on a holder 16 on the carrier 6 which is at station A, the gripper arms are open, and the trough is in its lower position. The carrier is advanced by cylinder 8 and the trough is raised to an intermediate position by the cylinders 24a, 24b so that the holder 16 can be gripped by the arms 32a ... 32d upon operation of the cylinder 30. After gripping of the holder, the trough is lowered so that the carrier 6 can be withdrawn and is then raised to its uppermost position so that the workpieces are immersed in the abrasive and reciprocated therein by the drive 36, 37, 38, the movement being along a path determined by the guides 27a, 27b. At the end of the finishing treatment determined by a timer, the arm 28 is stepped at its mid-point by a magnetic switch on the disc 37, and the trough is moved to its lowermost position so that the carrier can be moved forward whereupon the trough is raised to its intermediate position and receives the workpiece holder when the gripping arms are released. The trough is once again lowered and the carrier moved on to the rails 5a, 5b for permitting replacement of the workpieces on the holder. In another embodiment, opposite ends of the workpiece are connected to the rods of vertical cylinders operated such that in one direction of the horizontal movement the workpiece is inclined in one direction and in the other direction it is inclined in the opposite direction. The workpiece may also have a vertical movement simultaneously with the horizontal movement. The trough is fed with slurry from a reservoir 39 and may be circulated and filtered. The machine may have guideways running across the front of the machine for a plurality of holders whereby workpieces can be removed and replaced on one holder while the other holder is moved into the machine for a finishing operation.