| 摘要 |
823,154. Lapping. SYNTRON CO. Jan. 31, 1956 [Feb. 1, 1955], No. 3127/56. Class 60. One or more articles such as rings 23, Fig. 1, are lapped by a lapping surface which is provided with a reciprocating motion in a path inclined to the surface so that a feeding action results between the surface and the article and there is a progressive relative movement between the surface and the article. While the feed movement may be linear, the apparatus shown in Fig. 1 gives the articles a circular or arcuate motion, for which purpose they are supported in a bowl 20 on a frame 8 which is carried by four inclined springs 6 from a massive base structure 1 enclosing an electromagnetic motor having its armature 16 secured to the underside of the frame 8. The motor is fed with alternating current, if desired through a half-wave rectifier, and, by reason of the disposition of the springs 6, results in the alternate downward and upward movement of the bowl in a helical path ; unless the rings are themselves heavy, they are pressed downwardly by a pressure plate 25 and the vibratory movement of the bowl therefore results in rotation of the rings about their own axes as they move in a circular path over the surface of the bowl. The bowl is faced with abrasive cloth or paper 22 or felt &c., and contains a lapping liquid or powder. When only the lower surfaces of the rings are being lapped, the lower face of the plate 25 is faced with cork, but for lapping the upper faces of the rings the cork facing may be replaced by abrasive cloth &c. and a bar 30 may be used to lock the plate to the bowl. In one modification, the rings 23 are urged against the cast-iron lapping surface of the bowl by superimposing weights on the pressure plate, and in another a fluid pressure device acts directly or through a spring on a plate which is supported by annularly-arranged bearings on the pressure plate so as to permit relative rotation of the latter. In the arrangement shown in Fig. 3, the bottom surface of the bowl is shaped to grind the lower surface of a ring 33 to part-spherical form and magnets 36, 37 provided centrally in the pressure plate 34 and bottom of the bowl serve both to centralise the plate and increase its pressure. When lapping optical flats &c., two depending fingers 61, 62, Fig. 6, from a bridge 60 disposed across the bowl are each arranged to engage a pressure plate 63 and, by the resulting friction, to give the plate an added twist as it revolves around the bowl ; in a modification of this arrangement, a hook-shaped finger depends from the bridge for coaction with a series of upstanding pins on a pressure plate for achieving the same object. The motor for vibrating the lapping surface may, alternatively, be of hydraulic or electric type and of rotary action ; the motion may be transmitted from the motor through guiding links or a rubber support.
|
