Patent GB-744728-A (GB)
Title: Improvements in or relating to photographic type-composing machines
IPC: B41B15/06
Filed: 1953-12-11
Abstract: 744,728. Photographic type-composing. KNIEHAHN, W. Dec. 11, 1953 [Dec. 13, 1952], No. 34635/53. Class 98 (1). A photographic type-composing machine comprises a number of parallel strip-shaped carriers provided each with a vertical row of characters and adapted to be fed from a magazine to an image slit in such a way that the character whose associated key on a keyboard is depressed is exposed in the image slit, whereby a line of characters can be arranged in a row, with variable spacers inserted between adjacent words, means for justifying each composed line of characters, so as to obtain uniform interword spacing, means for photographing the line image, and means for returning the carriers to their initial position after the line has been recorded. Character carriers.-Several forms of character carriers are described. The carriers may be cylindrically curved, but in the forms illustrated the characters are borne on strips moved longitudinally for selection. As shown at the lefthand side of Fig. 1 and in Fig. 3, the carriers comprise transparent strips 22 longitudinally movable in staggered relationship behind a slit 25 in a frame 24. Selected characters may be brought into register with the slit to compose a line. A spacer 23 is fixed at an angle to each strip 22 and to the next spacer. The characters are spaced from the left-hand edges of the strips by half the normal inter-character spacing, which varies from character to character, and the spacers 23 are stepped to extend beyond the plane of the right-hand edge of the character by the same amount. Double-wedge spacers are introduced between the spacers between words. For justification, the carriers 22 are pushed together until the spacers 23 abut, the excess length being taken up by the space wedges. The justified line of characters at slit 25 is then photographed. The righthand side of Fig. 1 shows a modification in which separate spacers are dispensed with and the carriers 33 are themselves stepped according to the character width. The carriers are staggered and have notches 34 which, when the carriers are pushed together, engage pins 35 which are movable along grooves 36. The pins may be wedge-shaped to ensure precise alignment of the characters in slit 25. In this case the carriers need not be transparent, since they overlap only outside the region defined by the slit 25. In a further modification, Fig. 7, the characters are placed in order of width on wedge-shaped strips, comprising pairs of strips 37, 38 tapering in opposite directions with their outer edges parallel. The pairs of strips may lie in a common plane or may be staggered, in which case they may be transparent with the characters borne alternately on the front and rear faces of the pairs of strips, so as to lie in a common plane or may be staggered, in which case they may be transparent with the characters borne alternately on the front and rear faces of the pairs of strips, so as to lie in a common plane. When the character widths do not increase along the carrier exactly evenly, the carriers may be made of resilient material so that errors may be taken up. Locating notches may be formed between the characters for engagement by spring-pressed wedges to align the characters in slot 25. The character carriers may be contained in a magazine, and several magazines with different styles of type may be used interchangeably. Character selection and justification.-The characters are selected by a keyboard which places stops in the paths of the character carriers so that their longitudinal movement is stopped when the required characters are in the slit 25. As shown in Fig. 15, tapered character carriers 37, 38, of the kind shown in Fig. 7, are arranged in rows in a magazine 53. The rows, which are seen end on in Fig. 15, comprise several founts of characters and may be moved bodily by means of a lever 56 acting through wheels 85, 86 to bring the required row to operative position above a strip 55 which moves to allow the character carriers to fall one after the other into a well 54. Electromagnets 49 are arranged in vertical rows, the rows being equal in number to the character carriers in a row and the number of magnets in a row being equal to the number of characters on each carrier. A keyboard 52 movable across the machine energizes a magnet 49 in each row in turn; thereafter a character carrier is allowed to drop until it reaches a stop 51 which is brought into its path by the energized magnet. A spring-pressed wedge 40, Fig. 16, is released to engage a notch 39 between characters to locate the carrier precisely. Space wedges 63 are inserted, initially by their thin ends only, between words. A ratchet wheel on the movable keyboard pushes the character carriers together towards the left-hand end of the line. When the line has been composed, a lever 67 is operated. The lever is connected to a rod 68 which presses all the space wedges 63 forward to justify the line, which is then photographed. The space wedges are then withdrawn by operating a lever 69 connected to a rod 70 passing through slots formed in the space wedges. The stops 51 and locating wedges 40 are withdrawn, so that all the characters fall to the bottom of well 54 and rest on a bar 71 by which they are lifted back into magazine 54, strip 55 moving back beneath them. Optical system.-The characters in slit 25 are illuminated by means of a tubular lamp 72, Fig. 13, and lens 73. An image of the line of characters is formed by a system of lenses 74, 78 on a photographic film 76, which is moved between exposures by means of a lever 77. Part of the light from the characters is reflected by a beam-splitter 79 and focused by a system of lenses and mirrors 80 on to a ground glass screen 81, which may be viewed by the operator.