Patent GB-186366-A (GB)
Title: Improved photographic printing apparatus
IPC: G03B27/06
Filed: 1921-04-02
Abstract: 186,366. Huebner, W. C., and Huebner- Bleistein Patents Co. April 2, 1921. Printing-apparatus.- Relates to apparatus for obtaining a series of images in registered positions on a printing or other sensitized plate, and comprises a double printing apparatus for obtaining two series of images simultaneously on two sensitized plates from two printing negatives. One of the sensitized plates can be replaced by a lay-out sheet or printed plate, and this section of the apparatus used for the visual registration of the prints on the other sensitized plate, a registering device being substituted for one of the printing g negatives. Various uses of the apparatus for obtaining colour printing plates and for other purposes are also described. The main features of the apparatus are as follows. The negatives d, Fig. 1, are mounted on holders 15, 16 hinged to main uprights 10, and can be independently adjusted in these holders rotatably and also towards and away from the sensitized plates B, B<1>. The centre of rotation of the negatives in their holders can be adjusted. The holders are held in operative position by a keeper 19, Fig. 86, and latching- bolts 18<a> and can be independently unlatched by handles 19<a>. Both holders can, alternatively, be simultaneously moved to bring the negatives out of contact with the sensitive plates by a movement of the keeper 19, from a handle, shaft 171. The same movement of the handle shaft 171 simultaneously releases the pressure blocks from contact with the sensitive plates when the pressure blocks are coupled up for this purpose. The pressure blocks can be uncoupled and independently adjusted towards and away from the sensitized plates and are further rotatably adjustable to conform to the angular position of the negatives. The sensitized plates B, B<1>, Fig. 9, are mounted between stretching-bars 55 on a common support E. This support is vertically adjustable in a carriage F, the latter being transversely adjustable on the main frame 12. These adjustments are effected from handles 90, 91 and 102, 103, Fig. 1, on the front pillar 14, one handle of each pair being for coarse adjustments by visible scales 110, 120, the other handle being for fine adjustments by finely divided scales. The readings of the latter are enlarged by projection and are viewed at openings 116, 123. The stretching-bars 55, Fig. 9, for the flexible sensitized plates B, B<1> are operated by screws 60 at each side of the plates and the screws can be separately or simultaneously operated. Lamp chambers H, Fig. 1, are hinged to the uprights 10 and are in two separable sections 190, 191, Fig. 38, both ventilated, and with spaced walls, one section 190 containing the lamp, the other, 191, a heat screen. The detailed features of construction are as follows. The negatives c', Fig. 4, is held on a transparent plate d by adjustable holding-means d<1>, so that its front face is in front of any other parts of the holding or securing means. The plate d forms parts of the holder D which is positioned against stops 30 on a rotatable index head 21 by securing-devices 31, 31a. The index head 21 rotates in the frame 16 on rollers 23, 23<a>. The two pairs of lower rollers 23 are mounted on arms 23b which are adjustable by eccentrics 24, 24a, Figs. 1 and 13, so that the centre of rotation of the index head and negative can be adjusted. The index head is rotated by a pinion 25. To allow for negatives of different thickness and a limited movement towards and away from the sensitized plate, the index head is mounted in a threaded ring 27, Figs. 13 and 14, and moved in this ring by a pinion 28. The ring 27 is locked by a pin 29, Fig. 1. The index head 21 is locked by a catch 26, Figs. 1 and 13, which is tangentially adjustable by screws 26b and moved into engagement with the index head by a screw 26a. The movement of the latching keeper 19, Fig. 36, from the handle shaft 171 is effected through a worm 180, Fig. 4, gearing 184 and the eccentric 186. Link-work connected with this gearing 184 and having a certain amount of lost motion is adapted to switch the printing-lamps off and on. The carriage F, Fig. 9, for the sensitized plate holding-frame E is on trolleys 40 which have eccentric shaft bearings 47 for adjusting the level of the carriage. The sensitized plates B, B<1> are mounted on the frame E by attaching-bars 55, Figs. 4, 8 and 9 which engage in seatings 58 on the holding-bars 56, 57. The attaching-bars 55 are movable against stops at the one end of the seatings 58 by screws 57a. The lower bars 57 are movable by the screws 60 to stretch the plates. The screws 60 can be drawn down together to stretch the plates as a whole by moving a rack bar 68, Fig. 9, as by a handle 69 and so turning eccentric shafts 65, Fig. 24, in the frame E. Each screw 60 is threaded through a guided shoe or extension 58<a> of the arm 57, and the lower stem of the screw 60 is mounted in a bushing 62 threaded through a guided collar 64, which is moved by the eccentric 65. The screws 60 are individually adjustable to tension the plate locally, either by turning the screw by the ratchet knob 70 or by turning the bushing 62 in the collar 64 by the knob 70a and so moving the screw 60 bodily. The frame E, Fig. 9, is mounted on corner-pieces sliding on T.guides 51 in the hollow standards 35 and is counterbalanced by weights 53. The lower bolts 52 attaching the frame to the corner-pieces allow a slight lateral play in the frame. One of the upper bolts 52 is tight in the frame and the other is secured in a block 52a which has a slight lateral play in the frame. This construction prevents any binding in the frame. For stepping the plate frame E vertically, the frame is fitted with screw collars 74, Fig. 4, on screw shafts 73. The shafts 73 are rotated from either of the handles 90, 91 on the central pillar 14, Fig. 1, through a shaft 80, gearing 79, 78, 75, Figs. 4 and 10, the grooved shaft 71 and gearing 72. An independent fine adjustment for setting the frame E is obtained by mounting the collars 74 in an outer collar bracket 74a, and by an adjusting worm 74b. For a rapid vertical adjustment the handle shaft 90, Figs. 1 and 4, directly turns the shaft 80. For fine adjustment the slow movement handle shaft 91 is coupled with the shaft 80 by a movable collar 96. To provide a free movement of the grooved shaft 71. Figs. 4 and 10, through the wheel 75 when the frame E is adjusted horizontally and avoid jamming, the wheel 75 is mounted free of the shaft 71, Fig. 37, in bearings 81. A collar 83 splined to the shaft 71 is coupled with the wheel 75 by a collar 84, Fig. 37a, having couplings 85, 86 which can slip in different directions relatively to the wheel 75 and collar 83 respectively. For horizontal adjustments of the frame E the carriage F is moved by a cord 100, Fig. 10, attached at opposite ends of the carriage and passing round pulleys 10<1>, and a drum 99, Fig. 4, loosely mounted on the shaft 80. The drum 99 is operated for quick motions by the shaft 103 and for slow or fine adjustments from the handle shaft 102 through a clutch 98<a>. The carriage F is locked against movement by a clamping sleeve 104 which is tightened on the drum 99 bv a screw shaft 105, Fig. 4, operated by a treadle 106, Fig. 1. The clamping-sleeve is released by another adjacent treadle 107. The pressure blocks 130, Figs. 4 and 26, are mounted in housings on the rear standards 11 and can be operated together from the front handle 170 on the central standard 14 or independently by handles 139a. The blocks are also angularly adjustable about two centres. Each block 130 is rotatably mounted on a stud 131<a> on a slide 131 which is adjusted radially by a screw 131b, on a head 132 of a shaft The shaft 133 is rotatably mounted in a carriage 134 and the block is also angularly adjustable from the micrometer worm head 148. The carriage 134 moves on rollers 137, three of which have eccentric shafts 139 adjusted by setting handles 142, to ensure that the block presses evenly on the plate. Each setting handle is roughly positioned by a screw pin 143 and has lateral fine adjustment screws 141, Fig. 31, engaging an arm 140a on the eccentric shaft 139. The fourth shaft 139<a>, Fig. 26, has a toothed wheel and handle by which the carriage 134 and pressure block are moved forward. For moving both pressure blocks together, the carriage 134 is coupled with a cam-operated slide 151 by a coupling-bolt 156. This bolt is moved by rack-and-pinion gear 161, Figs. 4 and 26, to engage a keeper 157 through which a screw 158 is threaded. The screw is mounted in the carriage and enables the keeper to be positioned to engage the coupling-bolt. Also when engaged the carriage 134 can be moved by the screw 158 to bring the blocks adjacent to the sensitized plate. The blocks in this way may be adjusted so that when moved together by the handle shaft 171, Figs. 1 and 4, they exert uniform pressure on the plates. The blocks are operated together from this handle shaft through gearing 172, 174. worm 176, Fig. 4, a common transverse shaft 178, and gearing 179 for each block, which turns the shaft 155, Fig. 26, and cam eccentric 153, thereby moving the slide 151 and carriage 134. As above described, the mechanisms for withdrawing the negatives from contact with the sensitive plates B, B<1> and for switching out off the printing-light are also actuated from the shaft 171.