Patent GB-190913935-A (GB)
Title: Improvements in Methods of Photographically Copying, Enlarging or Reducing.
IPC: G03B27/36
Filed: 1909-06-14
Granted: 1910-06-14
Abstract: 13,935. Marks, E. C. R., [Print Weave Co.]. June 14. Enlarging, copying, and reducing.-In apparatus for enlarging and copying wherein the focus is maintained in adjusting for different scales of enlargement, a support is provided for the adjustable lens slide, and a second slide carrying the object or design is movable on the lens slide. A source of light is mounted on the object - slide so that the light may move with the object when the slide is adjusted. The means for maintaining the focus is that described in Specification 13,934/09, and the apparatus is adapted as a step and repeat machine in which the size of enlargement is adjusted to obtain a definite number of repeats to fill the periphery of a printing-roller. The sensitive plate is mounted on a frame having transverse shafts 11, Fig. 2. The plate is vertically adjustable in the frame to obtain the vertical rows. The frame 10, carrying the lens slide 13 and copyholder slide 40, is mounted on the transverse shafts and is horizontally adjustable to obtain the horizontal repeats. The lens slide 13 is mounted on guideways in the frame 10, and the copy slide 40 is mounted on guideways on the lens slide 13. The lens slide 13 carries a depending frame 14 and is moved by the screw spindle 32, which is mounted in the bracket 27 on the frame 14 and turns in the nut 33 on the frame 10. The spindle 32 is turned by the worm 29 at the end of the spindle which gears with wheels on two vertical spindles 25, which are in turn actuated by worms 26 in gear with the wheel 22 on the grooved shaft 20. The grooved shaft 20 carrying the operating-handle 21 is mounted in the frame 10 and journals in the bracket 24, which is provided with bearings for the spindles 25 and is also fitted with a yoke 23 for retaining the wheel 22 in gear with the worms 26. The spindles 25 are guided in the lower and upper brackets 18, 27 on the frame 14. The rotation of the adjusting-shaft 20 and the spindles 25 in addition to adjusting the lens slide 13, serves also to adjust the copyholder. The spindles 25 are screw threaded at the lower end with a thread corresponding to the thread of the spindle 32. A yoke 34 moves on the thread and carries pivots for the lower ends of the levers 36, which pass through swivelling fulcrum slides on the frame 14 and at the other end pass through pivoted slides 38 on the copy slide 40. On rotating the shaft 20, the yoke 34 and pivots of the levers 36 are thus moved vertically through the same distance as the lens slide is moved horizontally by the spindle 32, thus maintaining CB, Fig. 7, always equal to CB<1>. The fulcrum slides are pivoted in the blocks 41 and are slidably adjustable by means of the nuts 44 in slots 42. The slots are placed so as to hold the centre of the blocks 41 always at equal distance from the centre lines in the direction of the motion of the pivot 38 and yoke 34 respectively. The blocks allow for lenses of different focus corresponding to the distance of I from CB or CA, Fig. 7, which is thus kept constant. The lantern 48 is carried upon an arm 47<a> on the copy slide 40, and moves with the object when the slide is adjusted.