Patent GB-106900-A (GB)
IPC: G03B27/06
Abstract: 106,900. Jackson, W. J. Mellersh-, (Huebner - Bleistein Patents Co.) Aug. 15, 1916. Printing-apparatus.-Relates to improvements in photographic printing-apparatus of the kind described in Specification 23684/08 and 23690/08 for printing upon sensitive surfaces on plates of metal or other material or on lithographic stones which are afterwards finished for printing in one or more colours. The apparatus is fitted with adjusting-means so as to adapt it (a) for repeating a number of like prints upon a single plate for printing simultaneously a number of impressions, (b) for arranging different subjects in a specified way for composing purposes, and (c) for multicolour printing where exact register is required upon the different plates. The sensitive surface C<2>, Figs. 1, 3, and 7, may be clamped in a holder C<1> readily attachable by pins c<2> to a frame C, which is slidable vertically in an upright carriage B, movablo horizontally in its own plane upon guideways h on the central frame A, Fig. 1 being a general elevation, Fig. 3 a part elevation at right-angles to Fig. 1 with the light chamber M removed and with the forward extension A' in section, and Fig. 7 a view, similar to Fig. 3, of the support B upon its carriage. The sensitive surface may also be adapted to move to or from the printing plate and the latter may be adjustable parallel with the sensitive surface. Upon the forward extension A' of the frame A a light chamber or support M, Figs. 1 and 11, carrying transparent printing-plates m<2> upon its several faces, is rotatably secured upon a carriage N which is adapted to run upon V-shaped guideways q', whilst partly supported upon wheels q<2> near the guide-ways, at right-angles to the sensitive surface, Fig. 11 being a central section of the light chamber viewed from the back of Fig. 1. A rotatable back support U having several removable press-heads u of varying size may be similarly mounted upon a rear extension A<2>. As shown in Fig. 7, the sensitive surface C<2> is vertically adjusted in the frame B by rack and pinion gear e<1>, e<2> operated by bevel-gear e<3>, e<4>, e<8>, e<9> and shaft e<5> from a handle e<11>, Fig. 3, or, for fine adjustment, the shaft e<5> is rotated by worm-gear f, f<1> from a handle f<3>. The worm f<1>, which is normally out of gear, is mounted in an eccentric bushing rotatable by a handle f<6>. The sensitivesurface holder may be locked in any position by rotating a band-wheel d<11>, bevel-gear d<8>, d<9> and shaft d<3>, the ends of which are screw-threaded and engage with wedged-shaped nuts d<5>; the edges d<2> of the frame C which slide upon the back of fixed bevels d carry movable bevelled pieces d<1> which slide upon the front of the bevels d, which are clamped between the surfaces d<2>, d<1> by operating the wedges d'. Upper and lower clamp-bars c<3> may be held in any position on the holder C' by screws which screw into straps on the ends of the bars and whose ends pass through holes in the holder C<1> and then engage a hole in the clamp-bar. The carriage B which runs in grooves h may be partly supported by leaf-springs upon wheels h<3>, the pressure upon which may be adjusted by screws h<5> which engage nuts mounted upon the centre of the springs. The traverse of the carriage is effected by a rack i<3> and pinion i<2> on the shaft I, fine adjustment being obtained by throwing worm-gear i<6>, i' into operative position by means of a handle i<11> which rotates an eccentric bushing in which the worm-shaft i' is mounted. The carriage may be locked in any position by a lever K<6> on a shaft k<3>, Figs. 1, 3, and 7, upon which eccentrics k<2> are keyed to engage with a cross-bar K, Figs. 7 and 11, which is thus made to press against flanges k<1> on the frame. The lever k<6> is automatically engaged and held by a latch k'. The vertical position of the frame C is indicated by a pointer l<7> and dial l<9> rotated by a pinion l<10>, and similarly the horizontal position of the carriage B by a pointer l and dial l<2>. The carriage N for light-chamber M may be traversed by a rack and pinion r, r<1> worked from a shaft R, and when in position for printing, rests against a stop s<5>, Figs. 11 and 23, adjustable by a screw s<6>; the carriage N may be traversed a short predetermined distance by means of an eccentric s on a shaft S rotated by a handle T so as to reciprocate a slide s<1> upon a frame s<2>; the slide s<4> may be locked to the carriage N by means of a bolt t actuated by a pinion t<3>. The handle T, Figs. 1 and 24, may be clutched either to the shaft S or to a sleeve v<7> to which a worm v<6> is keyed and which, through a worm-wheel v<5>, bevel-gears v<4> and v<2>, and worm-gear v, may be made to produce limited movement of the back support to and from the sensitive surface in a manner similar to the movement of the light-chamber. The clutch-device shown in Fig. 24 comprises a plate fixed to the hub of the handle T with teeth w<1>, w<2> on its opposite faces which may be made to engage respectively with teeth on a collar w on shaft S, and upon which the hub of the handle T may slide and turn, or with teeth w<3> on the sleeve v<7>, engagement being effected by rotating a screw w<4> which turns in the outer end of the hub and engages a screw-threaded hole in the end of the shaft S. The light-chamber M is rotated upon a. circular track n<3> upon its carriage N by a worm n<8> on a shaft n<9>, the weight being partly taken by a spring-bearing. Fig. 31 shows a bolt-device for securing the light-chamber when parallel with the sensitive surface. A lug o<1> on carriage N forms part of a nut co-operating with a screw o<3> and, in the operative position, the lug o<1> may be slid forward to engage a notch in the back of a plate o<2> depending from the light-chamber. The operative position is determined by moving the light-chamber until plate o<2> rides over a spring bolt o<4>, the rotation is then slightly reversed until plate o<2> rests against the side of the bolt o<4>. To clamp the light chamber and its carriage down upon their seats to prevent any movement when the bach support is pressed against the sensitive surface, the pillar p<1> clamped to a base-piste p is passed through a cross-bar p<3> supported upon eccentrics p<6> on a shaft p<5> and bearing under flanges p<4> on the frame A<1>. The endbearings of the shaft p<5> are slotted or made somewhat out of round to permit of slight vertical movement. The shaft and eccentrics are rotated by a handle p<8>. The lamp P is surrounded by a shield P' supported by the base-plate p. The back support U is mounted, moved, and clamped similarly to the printing-plate support M, or the hollow back support may be clamped down by a clamping plate and nut. The printing-plates m<2> are carried by holders or disks m<1> removably and rotatably attached over openings in the sides of the light-chamber which carries scales m<6>. The printing-plate m<2> rests flat upon a heavy glass face-plate m<7>, secured on the disk by corner pieces m<8>, and is held thereon by clamping-bars m<9> mounted on the holder disk and centrally pivoted by a screw m<10> on a slide-block m<11>, Fig. 40, which is a section of the device in the plane between the bar m<9> and block m<11>. Whilst the screws m<10>, m<15> are loose, the slide-block m<11> may be moved forward by a screw m<13> until the clamping-bar m<9> takes an even bearing upon the side of the printing-plate, the angular relation of the bar m<9> to the slide-block being adjusted by screws m<17> which screw into the slide-blocks and bear against screws m<15>, the nuts m<16> of which slide in grooves in the holder disks. On rotating handles m<18> on the screws m<15>, the bevel edges of the bars m<9> bear down upon the edges of the printing plates and hold them in position.