| 摘要 |
1,192,896. Making valves. ROBERT BOSCH G.m.b.H. 10 Feb., 1969 [10 Feb., 1968], No. 7014/69. Heading B3A. [Also in Division F2] In a method of making valve plates from thin, spring steel plate, a chemical or electrochemical process is used in at least a final stage of the formation of an edge of the valve plate. The plate is prepared by painting it with a photo lacquer and the outline of the plate is formed therein as an unexposed layer by exposing the plate through a sheet of transparent material with blackened regions corresponding to the plate outline. The layer is then removed. The plate is connected as an anode in an electrolytic bath and the valve plate electro-chemically machined out. Alternatively the valve plate is chemically etched in an etching bath. In a second embodiment, the valve plate is stamped out about 0À5-1À0 mm. oversize and brought to its final dimensions electrochemically. |
