GB652655A - Improvements in or relating to lapping machines - Google Patents

Abstract

652,655. Lapping. STEVENS, A. H. (Crane Packing Co.). April 16, 1948, No. 10606. [Class 60] Apparatus for forming a surface of predetermined contour upon one or more articles comprises a lap 1, means for holding the article or articles on the lap, means for establishing relative movement between the article or articles and the lap and means for preserving the contour of the lap which means comprises a ring 61 adapted to wear the surface of the lap and a support to allow the ring to rotate freely relative to the lap surface. The articles are received in holes in a plate 62, Fig. 3, free to rotate on the pointed end of a spindle 56 and are subjected to pressure by a plate 66 which may have previously been lapped to the same contour as the lap. A layer of felt 65 is interposed between the plate 65 and the articles. The plate 62 is surrounded by the ring 61 which is rotatively connected with the spindle 56. The latter supports a pulley 57 connected with those on the spindles for other similar work holders by a belt 77, Fig. 2. If all of the pulleys 57 are of the same diameter the wear rings will rotate at the same speed as'the lap, while if certain of the pulleys are reduced in diameter or if one of the pulleys is enlarged, the wear rings will rotate at a slower speed than the lap. The wear rings drive the plates 62. The spindles 57 are adjustably secured in slots in a framework of members 48, 49, 50 and by regulating the position of the spindles together with their wear rings .relative to the inner and outer edges of the lap the surface of the latter may be maintained at, or formed to, the desired contour. The member 48 is bolted to tubers 39 which are externally threaded, provided with nuts 42 and slide in tubes 40. Each tube 39 is provided with a number of holes 43 one of which is brought into alignment with a hole in the corresponding tube 40, a bar 46 then being inserted in the aligned holes and the nut 42 tightened when the member 48 is at the desired height. The lap is driven at about 50 r.pm. by a motor 10 through a reduction drive and is provided with an annular trough 25 mounted on adjustable supports 29. Oil-borne abrasive from an agitated vessel 78 is fed to the lap by a wire 80. Radial grooves 34, 35 then collect and discharge it to the trough where the abrasive settles out and the oil is drained off through an adjustable pipe 31 to a tank 33. Work tables 16, 17 are mounted on adjustable supports 19. The lap and the wear rings may be of cast iron. The lap surface may be dressed by a single wear ring of considerable weight, e.g: 250 pounds, which has an external diameter in excess of the radial width of the lap.