Patent GB-448108-A (GB)
Title: A new or improved machine for treating printing plates
IPC: B23D1/00
Filed: 1934-11-26
Abstract: 448,108. Shaving printing - plates. HOE & CO., Ltd., R., 109, Borough Road, London.-(Huck, W. F.; 8926, 120th Street, Richmond Hill, New York, U.S.A.) Nov. 26, 1934, No. 34013. [Class 83 (iii)] A plate-shaving machine has electrically-controlled power means for reciprocating the work-supporting table and electrically-controlled means for positioning the shaving tool in an operative position during table movement in one direction and raising it from the work for the return movement. The side members 12, 13 of the frame have inturned ribs 14, 15, which support the projecting edges 16, 17 of the sides 18, 19 of the reciprocating work-table 20. The table includes a part 24 vertically guided at 27, 28 on the sides 18, 19 and resting on inclined longitudinal edges 34, 35 of a lower member 38 which may be moved longitudinally by screw-and-nut mechanism 38 operated from a hand wheel W. This longitudinal movement of member 38 raises the part 24 carrying the work 21 in order to determine the depth of cut. The table is reciprocated by a screw 30 driven through gearing 31 from a motor M. A recess 301 in the screw receives a guide rod 24<1> secured to the table part 24. The work is held down by an assembly 40 hinged at 40<1> and connected at 41 to turnbuckles 42, 43 which are pivoted to brackets 44, 45, on a shaft 46 supported on extensions of the main frame. The assembly includes rollers 50 which are urged downwards into contact with the work by springs. The shaft 46 may be rotated by handles 49, 49<1> to raise the hold-down to an inoperative position, Fig. 1. A spring 48<1> balances the weight of the assembly and maintains the hold-down in either the operative or inoperative position. Fine adjustment of the assembly to engage it evenly with the work is effected by the turnbuckles 42, 43. An additional adjustable hold-down 52 for the work comprises side pieces 54 between which are located a number of yokes carrying rolls 52<1>, Fig. 6, and urged downwards by springs, whose action is limited by stop pins 53<2>. The shaving knife 57 is secured to a member 571 hinged to the side frames. An arm 58 of the knife holder is connected to the plunger of a solenoid S which is operated to bring the knife into and out of operative position. The motor M driving the table, and the solenoid S are controlled by switch gear (not shown) and limit switches 61, 62 respectively coact with lugs 61<1>, 62<1> on the table to limit the table movement. One end of the work abuts against a stop 72 while the other end engages a stop 63 which is adapted to yield in a vertical plane as the knife shaves the end part of the plate. The stop 63, Fig. 11, comprises a bar 64 secured to the table by screws and recessed to accommodate a number of bars 67 engaging the end of the work and seated on resilient material 68. By this construction the stop yields vertically under the cutting pressure and allows the end of the work to engage firmly with the bed plate and prevent the knife from cutting more deeply at the rearward end of the work. The depth of cut is preferably indicated by a meter 73 operated by a bell-crank lever 74, Fig. 5. One end plate 76 of the bell-crank engages a pin 77 axially adjustable to compensate for wear in a block 78 mounted on the end of a rod 81 secured to an extension of socket 29 forming part of the table 24. The pin 77 is also movable to or from the pivot 75 of the bell-crank. Thus as the table 24 is adjusted vertically the pin 77 operates the lever mechanism to indicate the setting to an accuracy of À001".