GB1212492A - A method of and apparatus for lapping balls - Google Patents

Abstract

1,212,492. Lapping. S. MESSERSCHMIDT. 8 Jan., 1969 [8 Jan., 1968], No. 1133/69. Heading B3D. A method of lapping balls between two coaxial discs which are formed with grooves in which the balls run, comprises (i) rotating one of the discs, the other disc being held stationary and formed with a sectorshaped recess; (ii) feeding balls to the recess; (iii) receiving balls from the recess; (iv) guiding the balls, after each rotation between the discs, through a magazine; and (v) interrupting, when the balls have become substantially identical in size and shape, the connection between the sector-shaped recess and the magazine; and (vi) allowing the balls to rotate continuously between the lapping discs until they have the required maximum surface finish. A lapping machine has a lower lapping disc 1, with grooves 3, rotated in the direction 12. An upper lapping disc 5 can be raised but is non- rotatable; it has a sector-shaped recess 7. The discs 1, 2 are mounted eccentrically within an annular magazine 8 comprising a plate 14 with wall 15, rotated in the direction 13, and a stationary inner wall 16 having a gap 17 in register with the recess 7. A sheet steel guide member 18 secured to the disc 5 extends into the recess. In operation, balls 4 make alternate circuits round the working space between the discs and round the magazine. When the balls are substantially identical in size and shape, the guide member 18 is removed and the gap 17 of the wall 16 is closed by a member (24) secured to the disc 5. The balls between the discs make repeated circuits round the working space while the other balls remain in the magazine.