GB1439749A - Apparatus for vibratory finishing - Google Patents

Abstract

1439749 Vibratory finishing ROTO-FINISH Ltd 5 Sept 1973 [5 Sept 1972] 41126/72 Heading B3D [Also in Division F2] A method of operating a vibratory finishing machine having an annular chamber 11 and a vertical rotatable shaft on which is disposed axially spaced eccentric weights 13, 14 one of which leads the other by a given angle, comprises driving the shaft in one direction with one weight leading the other, and altering the relative angular positions of the weights so that the second mentioned weight leads the first, the shaft being rotated in the same direction, whereby to impart to the mixture in the chamber a reversed circulatory movement which facilitates delivery of the mixture on to a separating screen. The chamber 11 is supported by springs 15 from a base 16 and a motor is mounted with its shaft extending along the axis of the chamber with the weights 13, 14 at opposite ends. During finishing, the material moves around the chamber in one direction and after finishing moves in the opposite direction, a flap 18 being lowered into the chamber so that the mixture moves on to a screen through which the finishing medium drops back into the chamber. The reversal of the circulation of the material in chamber 11 is effected by altering the angular position of weight 13 relative to weight 14. The weight 13 consists of a loose mass, such as balls 25, Fig. 5, which are disposed in a container 24 carried by an arm 23 rockable about a transverse pivot 22 on the shaft 21 of the motor 12, a toggle spring 26 being disposed between the arm and the shaft. In operation, rotation of shaft 21 for the finishing operation causes centrifugal force to act on the balls so that the arm 23 pivots to its opposite position (Fig. 6, not shown). At the end of the finishing operation, the rotation of shaft is stopped or greatly slowed down so that the balls roll, by gravity, to the opposite end of the container. Upon rotation of the shaft the arm again moves about its pivot but this time the balls are in the opposite angular position so that the direction of circulation of the material in the chamber is reversed. The shaft may rotate in the same or opposite directions.