| 摘要 |
1,153,015. Electrolytic machining. PHILIP MORRIS Inc. Jan.25, 1967 [Feb. 10, 1966], No.3798/67. Heading C7B. A method of electrolytically shaping a surface on a continuous conductive workpiece comprises passing said workpiece past anode and cathode in spaced relation therewith, the cathode having a working surface adapted to generate the desired predetermined shape on the surface of the workpiece, the gaps between workpiece and the anode and cathode respectively being filled by electrolyte so that the workpiece forms a bi-polar electrode, and electro-machining thereof may take place without physical contact between electrodes and workpiece. The invention is particularly applicable to the sharpening of continuous strip razor-blade blanks. Using the apparatus shown a razor-blade strip 11 is passed through a slit 18 formed in a fixture 10, to which electrolyte is supplied via inlets 20, 21 and feed channels 22, 23, which fixture is provided with anodes 25, 26 extending into said slit 18 so that one edge extends longitudinally therealong (see portion 27) parallel to the razor-blade strip, cathodes 30, 31 extending into the slot throughout its length and having working surfaces 32 positioned parallel to the blade edge to be sharpened and at a distance of less than 0À010 therefrom, and an electrolyte outlet 38, constructed such that the electrolyte pressure, which may be up to 350 lb/ square inch within the slit 18, drops considerably after passing between the cathodes 30, 31. In this form part of the current flows direct from anode to cathode without passing through the workpiece. Embodiments are also shown in which the chambers forming the slot through which the workpiece passes and into which anodes and cathodes are passed are maintained separate from one another, to thus prevent contamination of the catholyte by chlorine formed at the anode Fig. 4 (not shown); in which the strip is passed through the apparatus horizontally, two sets of electrodes being positioned therein such that both edges of the blades are sharpened therein, Fig. 6 (not shown) the workpiece being passed therethrough by means of a sprocket wheel which engages the slots formed in the razor blades Fig. 5 (not shown); and in which the cathodes may be adjusted laterally of the blade strip by a worm gear arrangement. An electrical circuit is described Fig. 1a (not shown) in which current from a 3-phase A.C. source is fed to the electrolytic cell via silicon controlled rectifiers connected respectively with bi-pass diodes to allow variation of the current, a transformer bank, diodes for rectifying the current, a filter capacitor for smoothing the resultant D.C. current. The cell may be operated using either constant current or constant voltage. |
