GB287588A - Process and apparatus for forming pin points and cutting edges - Google Patents

Abstract

287,588. Coles, S. O. Cowper-. Sept. 27, 1926. Metals, removing.-Points or edges are formed on metal blanks by electrolytic removal of metal, the blanks being connected as anodes, and held with their points or edges directed towards the cathode. In the apparatus shown the blanks are held with the ends to be pointed directed downwards between pairs of bars extending across a frame, situated above a tank E<1>, Fig. 2, mounted on a trolley E. The cathode consists of a large number of bars of triangular section extending transversely along the bottom of the tank and resting on longitudinal conducting bars. The frame is provided with rollers b seated on inclined tracks C and is connected by a connecting-rod to a crank disc G geared to a power-driven disc h, thereby being given a vertical and a lateral reciprocating motion. The reciprocating gear is mounted on a frame K which is mounted on a screw J actuated by the reciprocating motion through a ratchet h<2> and ratchet wheel j and a worm and wormwheel, not shown, so as to superimpose a reduced continuous motion up or down upon the reciprocating motion of the frame. The frame may be restored to its initial mean position by a handwheel or automatically. Alternatively the level of the electrolyte may be lowered during the operation. The blank-holders may consist of main bars D, Fig. 5, and gripping layers done of which is of brass and is grooved to receive the blanks, the other being of lead or rubber. The bars are secured together by hand-wheels d' and are secured to the frame B by hand-wheels d<2>. The blanks may be staggered after being placed in position in the holder by means of a comb, the blank-holders being reversed in the frame after formation of one set of points. The current may be reversed to clean the surfaces at the end of each pointing operation. The edges may be formed with a step or shoulder instead of a gradual taper by appropriate regulation of the vertical motion or level of the electrolyte. Specification 13980/07 is referred to.