GB1249056A - Grinding apparatus - Google Patents

Abstract

1,249,056. Tumbling. I. OHNO. 24 Feb., 1969, No. 9810/69. Heading B3D. Tumbling apparatus comprises a rotary drum on which are mounted cylindrical or polygonal containers each on a rotatable shaft parallel to the drum shaft, the cylindrical axis of each container being inclined to its shaft. The arrangement is such that the material being treated and the abrasive move in a figure eight path within the containers during drum rotation and rotation of the containers relative to the drum. A drum comprises discs 4, 5 connected by a shaft 6 rotatable on a shaft 2 fixed to a base 1. A motor 8 drives, through a belt 10, a pulley 7 fixed to the disc 4 to rotate the drum, e.g. at 200 r.p.m. Four containers 12, having openings closed by lids 13, are rotatably mounted in the drum by shafts 11 parallel to the shaft 2; the axes of the containers are inclined to the axes of the shafts 11. Gears 14 fixed to the shafts 11 mesh with gears 15 journalled on the disc 5 and meshing with a gear (16) fixed to a shaft 24 journalled on the shaft 2. A forked member 17 supported by a pin 18 surrounds the shaft 24, rotation of the latter being prevented when the member 17 is closed by a screwthreaded rod 19 operated by a handle 21; the containers 12 will then rotate relative to the drum oppositely to the direction of rotation of the drum and with the same angular velocity if the gears 14, 15, 16 are all of the same diameter. Due to centrifugal force resulting from rotation of the drum, the container contents travel round the container as shown at s, and travel axially of the container as shown at t.