Patent GB-1224050-A (GB)
Title: Self-separating vibratory finishing apparatus
IPC: B24B31/073
Filed: 1968-12-24
Abstract: 1,224,050. Vibratory finishing. SHIKISHIMA TIPTON K.K. 24 Dec., 1968 [28 Dec., 1967; 20 April, 1968; 10 May, 1968], No. 61233/68. Heading B3D. [Also in Division F2] Apparatus for finishing workpieces by agitating them in a container with an abrasive, comprises means for vibrating the container including a reversible electric motor driving a shaft carrying a pair of eccentric weights, one of which always leads the other by a predetermined angle when the motor rotates in either direction. The vibration produces helical motion of the material within the container. The apparatus is arranged to separate as well as finish. A pedestal 10 has shock-absorbing legs 12, e.g. of rubber, and a cover 14 enclosing helical springs 16 fixed to the pedestal and supporting a base flange 18 to which is secured a tub 20 comprising an annular trough 22 having a semi-circular cross-section bottom 24. A housing 26 extends from the centre of the trough into the pedestal 10 and has fixed to the interor of its lower portion a vibration generating unit 28. A sieve 30 is fixed on the top of the trough so as to cover a portion thereof, and has except at one end a peripheral ridge 32 which forms at the other end a discharge opening 34. A flap 40 is pivotally mounted on a rod 38 so that it can move between its inoperative position where it  is horizontal and its operative position where it is inclined, the flap having a profile such that in the inclined position it is engaged on the periphery by the internal wall of the trough to provide a bulkhead for the trough. The flap 40 has a flat protrusion 42 on the upper half of that portion near to the inner side trough wall of that face thereof remote from the sieve; the lower end of the protrusion is curved. The upper part of the outer wall of the trough may be curved inwardly at 80. The vibration generating unit 28 comprises a vertically disposed reversible electric motor 44 mounted by flange 46 and annulus 48 in the housing 26. The motor shaft 50 carries upper and lower eccentric weights 52, 54, Figs. 6, 7. Each end of the shaft 50 has keyed at 56 an exchangeable sleeve 58 having a circumferential groove 60 over a predetermined extent; the extent may be the same or different for the two sleeves. The hub 62 of the eccentric weight is fitted on the sleeve with a control member 64 on the hub disposed within the groove 60. The weight can be secured for rotation with the shaft by a set screw 66 extending through the hub 62 and member 64 into the sleeve 58. The upper weight 52 may be secured to rotate with the shaft, the lower weight 54 being free. When the shaft rotates clockwise, weight 54 assumes position 54-1 so that weight 52 leads it by angle c; when the shaft rotates counterclockwise, weight 54 assumes position 54-2 so that weight 52 leads it by angle d. The lower weight 54 may be secured to rotate with the shaft, the upper weight 52 being free. When the shaft rotates clockwise, weight 52 assumes position 52-1 so that weight 54 leads it by angle b; when the shaft rotates counterclockwise, weight 52 assumes position 52-2 so that weight 54 leads it by angle a. Both weights 52, 54 may be free, the angle between them being a-c or b-d according to the direction of rotation. The weights may be stepped; their mass may be adjusted by additional weights 75.