Patent GB-303186-A (GB)
Title: Method of and machine for photographic composing for printing plates
IPC: G03F7/22
Filed: 1927-06-30
Abstract: 303,186. Boedicker, H. C. June 30, 1927. Enlarging, copying, and reducing. - A step- and repeat machine, more especially for making negatives, and repeating exposures on a sensitized surface for making printing-surfaces, comprises a projector movable in four directions in the same plane and adjustable relatively to a 'table support for a sensitized surface or an original, and adjustable positioning members for predetermining successive positions of the projector. The projector can be adapted for use as a camera. The positioning members comprise wedge-shaped slots, in which wedges or keys, on movable handles on the projector can engage. In the apparatus described the main frame A, Fig. 1, is formed of unitary rectangular end members 1 and disconnectible transverse members 2. The table B is vertically adjustable within the frame A by screw shafts 7 and interconnecting shafts 12, 20 operated from the handle 13. For centering a plate holder, or an image, the table B is formed with transversely - extending grooves adapted to receive cross bars 21., 22, which may either fit or be integral with the plate-holder. To secure the table in focused position a vertical focusing gauge-bar 24 has wedge-shaped notches 24<x>, engaged by a key 26, Fig. 6, on a handle 27 pivoted at 28 to the table. The projector, which is adaptable as a camera, is carried by a saddle carriage 34 - - 37, and this carriage is transversely movable on the frame A. The saddle 29 has a bar 40 at one side moving in a V-groove 41 of the carriage member 35, and is fitted at the other side with wheels 30 rolling on the member 34, these wheels being mounted in eccentric bearings to adjust the level of the saddle and. projector. The member 37 of the carriage has similar adjustable wheels 39. and the member 36 travels. in a V-channel 38 on the frame A. To set the projector-camera accurately in predetermined positions, a series of registry blocks 84 having V-slots are adjustably mounted on bars 83 carried by the saddle carriage, and are engaged by wedges on pivoted handles 88 of the saddle 29. Similar adjustable registry blocks 89 are mounted on bars 90 carried by the frame A, and similar handles 88<x> are pivoted on the saddle carriage. For projection, a lamp house E is hinged to the saddle 29 by brackets 42. The projection lamp F is mounted on a baffle plate 46 of a three-section ventilator cap. The condensers 55, 59 are secured against a ledge 56 by a bottom ring 60, and screws 61 each engaging a fibre positioning strip 62. A diffusing disc is interposed between the condenser lenses by means of rings 57, 58. The casing also has a pilot window 50, and light-trapped ventilators 54. The upper surface of the saddle 29, which has a central opening, is fitted with pins and clips 65, Fig. 7, to register a mask 63, having lines 67, 67<x> to centre an image 66 or a sensitive plate. Bellows 68 extend between the saddle 29 and a focusing lens mount F carried by a plate 75 which is carried by rack focusing rods H slidable within sleeves 78 bolted to the saddle 29, and centred in the sleeve by conical split bushings 79, Fig. 11. The rods are racked simultaneously by a handle 102 actuating shafts 100. 105 which have pinion sections and are connected by a shaft 104 through bevel gearing. The rods H also have apertures 81 into which bolts 82 can be engaged to support and fix the rods in any required vertical position.