Patent GB-499930-A (GB)
Title: Improvements relating to methods and apparatus for photographically composing text matter
IPC: B41B15/02
Filed: 1937-04-27
Abstract: 499,930. Photographic type-composing. WESTOVER, G. April 27, 1937, No. 12610/38. Divided out of 499,859. [Class 98 (i)] Text matter is photographically composed into page form from a number of composed lines by means of a lens or lens system rotating between a line-carrying element and a light-sensitive sheet element so as to sweep along an exposed line of text and project it on to the sheet element. A tube 10 carrying the lens 16 is rotatably mounted in bearings 11, 12, and a shutter 10a is arranged at one end. The lens is transversely mounted in a block 17, and a reflecting prism 21 is mounted in an aperture 20. Light is projected from an external lamp longitudinally along the tube 10 to lens 23 and thence is reflected at 21, 24, 26 to the lens 16. The strip bearing the composed lines is carried by one of a number of interchangeable rotatable drums having a diameter suitable for the point size in which the page reproduction is required. The drum is mounted on a cylindrical support 28, concentrically with the lens tube 10, the bracket being cut away at its lower part to allow passage of light to the lens 16 through the line of text to be projected. The drum is provided with a single or double line of sprocket teeth to engage perforations in the line strip. The lightsensitive page sheet 32 is carried on the inner surface of a cylindrical member 33 between the tube 10 and drum 27, the position depending on the magnification required. The dark slide is mounted on a carriage 34, the ends of which are secured by rods 37 in blocks 38, with light-excluding strips 39. The carriage 34 is provided with rollers 40 running on rails extending between the uprights 6, 7. Two strip-carrying spools, of which one, 42, is shown, are mounted on the upright 7 in alignment with the drum around which the strip passes, one or both being suitably driven so that the strip passes over the drum. The shutter 10a, Fig. 19, slides horizontally in a member 46 and is actuated by a cam 48 through a bell-crank lever 47. The drive to the shutter and spool is taken from the lens tube, which carries a pair of mutilated gear wheels 51, 52, each engaging a gear wheel on a shaft parallel to the tube 10, of which one, 55, is shown. The shaft 55 carries a gear wheel engaging a gear wheel 58 carried by a shaft 59 on a swinging bracket 60. The shaft 59 carries also pinions 68, 69 engaging peripheral gears on the drum. The bracket 60 is adjustable to accommodate different sizes of pinions. The intermittent feed of the dark slide is effected through gearing 70, 71, 72, the lastmentioned being threaded on the spindle 73 which is thus moved axially, carrying the dark slide. In operation, the tube 10 rotates continuously, and the drum 27 is driven intermittently to present in succession each line of text on the strip at the lower cut-away part of the bracket 28. The shutter is opened, and light passing through the lens system traverses the exposed line of type and is projected on to the page sheet. During the idle portion of the revolution of the lens tube, the dark slide is moved forward into position to receive the next line, which during the same period has been brought into the projection position. Specification 499,859 is referred to.