Patent GB-1100320-A (GB)
Title: Finishing machines
IPC: B24B31/073
Filed: 1965-11-18
Abstract: 1,100,320. Vibratory finishing. ROTO-FINISH CO. 18 Nov., 1965 [27 Nov., 1964], No. 49069/65. Heading B3D. A finishing machine for finishing the surface of a part by vibration of a mixture of the part with a finishing material comprises (i) a housing mounted for vibration defining a substantially horizontally oriented curvilinear finishing chamber; (ii) an elevator duct mounted in the housing having an entry port at one end positioned at a lower level and generally in the extra-median zone of the chamber and terminating in a discharge port positioned at an upper level, (iii) separating means associated with the discharge port for separating the finishing material from the part and returning the finishing material to the chamber; (iv) vibration generating means operatively associated with the housing for subjecting the mixture of the part and the finishing material to vibration causing the mixture to travel linearly along the chamber and undergo an orbital motion having an upward direction in the extramedian zone of the chamber and a downward direction in the intra-median zone thereof for finishing the part and to cause the mixture to rise substantially vertically in the elevator duct, and (v) means for discharging the part. In one embodiment, Figs. 2, 4, a base-plate 3 is mounted by helical springs 4 on a base 2. Mounted on the plate 3 substantially horizontally is a curvilinear finishing chamber in the form of an annular trough 7 having an arcuate bottom. Transverse or diagonal vanes or baffles may be positioned at intervals along the trough bottom. The finishing chamber may be in the form of a tube, tray, etc. Mounted on the plate 3 within the trough 7 is a cylindrical frame 8 supporting a motor 9; eccentric weights 12, 13 are mounted on the ends of the motor shaft. One weight or more than two may be used. A partition 14 in the trough divides a charging zone (15) from a discharging zone (16), the major part of the trough constituting a finishing zone (17). Mounted at the partition 14 is discharge means comprising an elevator duct 18 in the form of a vertical tube of rectangular cross-section having its lower entry end 19 below the surface of the contents of the trough and in the circumferentially outer zone of the trough where the finishing motion of the contents is upwards. Its upper exit end (20) is above the surface of the contents of the trough. Fixed to the upper end of the duct is separator means comprising a tray 22 having a screen 23 and terminating in a discharge spout 24. Finishing material falls through the screen into the charging zone; finished workpieces pass over the screen and are discharged through the spout 24 to a receptacle or conveyer. The partition 14 may be omitted. The tube forming the elevator duct may be inclined from the vertical and may then have vanes or baffles. The tube may have a cross-section which is round, elliptical or otherwise ovular, rectangular, hexegonal, octagonal etc. In another embodiment, Fig. 5, the means 38 comprising an elevator duct 39, a screen 41 and a spout 42, is detachably mounted on the wall of the trough 30 by a screw clamp 43. With the means 38 detached, the contents make a number of circuits of the trough 30; when the workpieces are finished, the means 38 is attached and the workpieces are discharged from the spout 42, the finishing material returning through the screen 41 to the trough 30. In a modification, the means 38 is permanently secured to the trough and the screen 41 is hinged, retractable or removable so that it can be rendered inoperative, whereby workpieces as well as the finishing material are returned to the trough. In another embodiment, Fig. 9, for multistage finishing, chambers 44, 45, 46 contain respectively coarse abrasive, medium grade abrasive and fine finishing material. Workpieces are placed in the chamber 44, subsequently discharged through duct 53 into the chamber 45 subsequently discharged through duct 54 into the chamber 46 and finally discharged through spout 55. The finishing material discharged from each chamber is returned to the same chamber. The troughs used in the above constructions may be elliptical, ovular or asymmetrically curvilinear. The finishing chamber may have two ends. The eccentric weights are preferably positioned 45 degrees apart. The vibratory means may comprise an electric motor, an hydraulic motor, a pneumatic motor or a prime mover. When finishing metal workpieces with non- magnetic finishing material, magnetic separation may be employed.