Patent GB-685310-A (GB)
Title: Justification mechanism for type-composing machines
IPC: B41B21/36
Filed: 1950-01-20
Abstract: 685,310. Photographic type - composing. HIGONNET, R. A. E., and MOYROUD, L. M. Jan. 20, 1950 [Jan. 29, 1949], No. 1576/50. Class 98 (i). [Also in Group XVI] Justification mechanism for a type-composing machine comprises a chamber containing a liquid; means for varying the volume of the liquid in the chamber from an initial volume towards a second volume by an amount proportional to the total width of all the characters in a line to be justified; adjusting means for bringing the volume of the liquid in the chamber to the second volume by a series of equal changes in volume equal in number to the interwords in the line; character-spacing means responsive to the changes of volume of the liquid in the chamber; the volume-varying means being adapted, after the composition of each character of the line, except the last, to restore the volume of liquid in the chamber towards the initial volume by an amount corresponding to the width of the character, and the adjusting means being adapted, during the composition of each interword, to bring the volume of the liquid nearer the initial volume thereof by a change equal to one of the said series of changes. The line to be composed is registered character by character by means of a code of several elements, four of which determine the width of each character. As shown, four pistons 7, 8, 9, 10 can be advanced step by step by equal distances into a cavity 1 filled with oil or similar liquid. The areas of cross-section of the pistons are in the ratio 1 :2 :4 :8, and one or more of them are advanced, according to the code elements, each time a key in a character-selection keyboard is struck. As the pistons advance, a piston 4 is pushed out against spring action, until the end of the line is reached. Piston 4 is then a small distance from a stop. Each time the space key is pressed, a member 15 is moved over a row of pistons 14 by a distance equal to the distance between adjacent pistons. When the line is registered, a presser member 18 is pressed down on the pistons 14 which are forced into chamber 1 until piston 4 reaches its stop. A valve 2 is then operated, placing chamber 1 into communication with a cylinder 3 containing a piston 23 on a rod 24 and communicating on the other side with another cylinder with a spring-pressed piston 25. During printing, the pistons 7, 8, 9, 10 are moved back step by step in accordance with the character widths under control of the register, so that piston 23 moves a distance equal to the width of each character. Rod 24 controls the character spacing and for this purpose is connected, e.g. to the carrier for the photographic material in a photographic type-composing machine, or to the carriage of a justifying typewriter. When an interword space is required, member 15 moves back one step to release one of the pistons 14, which moves outwards under the oil pressure and causes a spacing movement providing a space between two words. In this way, as the line is printed, the distance by which the line is short of the required length is divided amongst the interword spaces. On completion of the line, piston 25 is pulled back by electromagnet 29, thus returning pistons 4, 23 to their original positions. A second oil-filled cavity with a similar arrangement of pistons may be used so that one is used for storing a line while the line previously stored in the other is being printed. The length of the justified line can be altered by adjusting a screw 30. If the size of the characters is altered, a screw 31 is adjusted, and other similar cylinders are connected to cylinder 3. Interword spacing may be controlled entirely by pistons 14 as described, or minimum interword spacings may be registered by means of one of the pistons 7, 8, 9, 10, the length by which the line is short being divided as before and added to the minimum interword spaces. Specification 669,531 is referred to.