Patent GB-190226444-A (GB)
Title: Copying Machine for Sinking Dies and Analogous Uses.
Inventor: ALLISON CHARLES ARTHUR
Filed: 1902-12-01
Granted: 1903-12-01
Abstract: 26,444. Allison, C. A., [Powers, D. E.]. Dec. 1. Milling.-A copying-machine for cutting or sinking in a block of steel or other suitable material a die or the like of a form corresponding to any given pattern, has compound slides W, W<1> mounted on a bed T, and carrying the pattern M and block M<1> respectively. The lower members C, C' of the slides are traversed during cutting by screws F, F<1> connected together by change gearing, so that they may be rotated in the same or opposite directions and at the same or different speeds to produce a copy of the pattern to any desired scale. The screw F<1> is driven in either direction from a shaft S<4>, inside which slides a rod R for reversing the traverse of the slides at the end of each cutting stroke. Ths shaft S<4> is driven by gearing from a shaft S<2> having a cone pulley P<4> driven from a shaft S<1> connected by a belt l<2> to the main shaft S, the shafts S, S<1> being supported in brackets on arms A, A' carried by brackets B, B<1> on the table. The lateral movement of the upper slides c, c<1> after each stroke to effect a displacement or feed of the pattern and block is effected by screws f, f<1> geared together by means of a telescopic shaft S<5> with two universal joints to allow the screws to be simultaneously operated in any position of the two lower slides C, C', the shaft S<5> being carried in hangers on the lower slides. The drill spindle D and tracer spindle D<1> are capable of vertical movement in bearings b, b<1> on the arms A, A<1>. The scale of reproduction of the raised portions of the pattern is determined by the adjustment of a block p<2> along one of two slotted arms e, e' carried by toothed segments q, q<1> pivoted on the frame and engaging racks r, r' clamped on the tracer and drill spindles, respectively. so that the two spindles rise and fall together in the determined ratio, the block p<2> having a pivot in the slot of the second arm. The drill spindle is rotated by bevel gearing G<1> from the shaft S<1>. In order that the spindles may be raised when any abrupt elevation occurs in the pattern, the tracer is subjected to a jarring movement, which lifts it and allows it to fall. The movement is produced bv a friction band encircling a disc on the pivot p of the segment q, the band being tightened by a rocking arm a to raise the tracer and then quickly released to allow it to fall. If the tracer is in contact with an abrupt elevation, its fall is prevented by the friction between the tracer and the pattern, so that the tracer is intermittently lifted over the elevation. A weight may be hung from pins on wheels gearing with a wheel on the pivot p to increase the pressure on the tool during a roughing cut. To provide for the automatic reversal of the traverse of the lower slides and the lateral traverse or feed of the upper slides at the end of each stroke a raised surface is arranged round the general outline of the pattern but appreciably higher than the highest parts of the pattern. The excessive raising of the spindles when the tracer makes contact with this surface causes an arm a' to raise the weighted end of a lever R<1> pivoted at p<3> and thus depress a rod R<2>, bringing a trip t<1> into the path of a cam K, independently driven and freely rotating on a shaft carrying a crankdisc V<6> and a gear-wheel g<8>. The cam further depresses the rod, allowing a one-revolution clutch to couple the cam tn its shaft to rotate the crank-disc V<6> and also, though gearing g<8>, g<7>, to impart a half-revolution to a second crank-disc V<5> connected by a rod U<1> to the rod R for reversing the traverse of the lower slides C, C<1>. The throw of the disc V<6> is adjustable, its pin being connected by a rod U<2> to a rack r<3> hung on links on a bar I guided in blocks W. If the bar can move freely in the blocks, the bar and rack are reciprocated together by the movement of the rod U<2>, but. if some friction is put upon the bar, the rack is first rocked on the pivots of its links on the bar, raising it into contact with a wheel g on the screw f<1>, after which the rack and bar move together to effect the feed. To enable the tracer to be accurately set vertically with respect to the drill, the tracer point t is carried by a screwed rod inside the hollow spindle D', the rod being pressed upwards by a spring and adjusted by a nut N on it bearing against the lower end of the spindle.