Patent GB-191211653-A (GB)
Title: Improvements in and relating to Photographic Step and Repeat Printing Apparatus.
IPC: G03B27/06
Filed: 1912-05-16
Granted: 1913-04-24
Abstract: 11,653. Neu-Graphic Akt.-Ges. June 2, 1911, [Convention date]. Printing - apparatus; step - and - repeat.-In apparatus for obtaining a pattern or design by printing successive contiguous impressions from a unit section, means are provided for separating the negative and sensitive surface for the successive shifting without altering their positions relatively to the scale used for shifting, and for obtaining an accurate angular adjustment of the unit section. Two forms of apparatus are described having circular and rectilinear adjustments respectively. In the one form, the sensitive plate 1, Figs. 1 and 2, is supported by a circular support 2 resting on legs 3. The unit section 6 is supported on a movable ring 7 carried by studs 8 which pass through the support 2. The studs 8 are raised and lowered to separate the design 6 from the plate 1 by a cam 11, which is rotated from a handle 14 and raises the cross-frame 9 connecting the various studs 8. The plate 1 is held between metal strips 4 adjustably secured to the support 2 and two springs 5 secured to an adjustable slide 17. The plate 6 is mounted between two angular pieces 18, 19 on the ring 7, the latter of which is radially adjustable in guides 20. The plate 6 is adjusted in such a manner that the apex of the unit section 32 includes a whole fraction of a complete circle and accurately coincides with the centre of the support 2 and ring 7, the rest of the plate 6 being opaque. After adjusting the unit section by means of a scale 30 on the frame 2, the plate 6 is inverted so that the unit section faces the sensitive plate 1 and is held by a spring-pressed finger 21. The ring 7 is connected by a series of studs 24 with a second ring 25 which is rotated from the head 28 by a rack and pinion 26, 27, and carries a pointer 29 moving over the scale 30. The studs 24 are vertically displaceable in the ring 25, and additional springs 33 are provided between the rings 7 and 25, which allow the ring 7 to move down evenly after being lifted to rotate the plate. In the second form, the plate 39, Fig. 6, is mounted on a frame 68 and is positioned between blocks 62, 63 on one side and springs 64 on sliding supports 65, which are secured in position by screws 67. The plate 41 carrying the unit section 40 is mounted on plates 42, 43, and is positioned by means of two wedges 52, 53, Fig. 8, which engage angular notches in the plate 41, having a wider angle than the wedges. The wedge 52 is on a slide 49 which is transversely adjustable on the plate 42, and the wedge 53 is on a slide 50, which is laterally adjustable on the plate 43. The plate 41 is adjusted so that the line joining the wedges 52, 53 is perpendicular to the direction of displacement of the plate, and the unit pattern is arranged on the upper face of the plate 41 and between two edges parallel with the line joining the wedges 52, 53. The plate is then inverted and is clamped in position by screw clamps 55, 56. For separating the plates 39, 40 during a shift the plates 42, 43 carry a set of vertical pins 44, 45 sliding in an adjustable supporting frame 48. The pins are raised and lowered by a transverse shaft 57 which is flattened at two parts 58, 59. When the shaft is rotated the flattened parts engage in the recesses in two of the pins and raise the pins and thereby the plates 42, 43 and the plate 41. The frame 48 is laterally adjusted step by step by the screw shaft 70, and carries a pointer 72 travelling over a fixed scale 73 which is read by means of a magnifying eyepiece 74, which is mounted in connexion with the plate 43.