| 摘要 |
1,240,111. Abrading. JOSEPH LUCAS (INDUSTRIES) Ltd. 24 Dec., 1968 [8 Jan., 1968], No. 981/68. Heading B3D. [Also in Division F2] An ignition distributer cam is manufactured by (i) grinding the cam to the desired profile, to leave the cam surface with sharp edged asperities defining therebetween channels which in use store lubricant; (ii) placing the cam in a container with abrasive particles; and (iii) moving the container so that the particles collide with the cam surface and round off the sharp edges without removing the asperities. This is stated to reduce the wear rate of cam followers made of synthetic resin. Distributer cam-shafts having cams ground to the desired profile, are treated in a vibratory finishing machine, e.g. one having an annular bowl 11 of generally semicircular cross-section filled with ceramic particles in the form of prisms. The bowl is spring mounted and is caused to vibrate in such manner that the prisms progress around the bowl from the lower portion 12 thereof in a substantially toroidal helical path towards the outlet 13 from the bowl. A small amount of soapy water is added to the bowl. |
