Patent GB-691761-A (GB)
Title: Improvements in or relating to registers in photographic type-composing machines
IPC: B41B27/32
Filed: 1949-11-16
Abstract: 691,761. Photographic type - composing. HIGONNET, R. A. E., and MOYROUD, L. M. Nov. 16, 1949, No. 735/51. Divided out of 691,738 under which a Specification was laid open to inspection under Sect. 91 of the Acts, May 25, 1950. Class 98 (i). A register for a photographic type-composing machine of the kind in which a composed line is stored in coded form prior to being photographed upon a light-sensitized surface, comprises a storage unit for storing characters in coded form, a recording carriage for entering characters in coded form into the storage unit and movable with respect to the storage unit, and a reading carriage for detecting stored characters in the storage unit and movable with respect to that unit independently of the recording carriage. The storage unit may comprise sets of movable elements, each element having a first or second stable position and each set serving to store at least one character in coded form. The recording and reading carriages may be arranged on opposite sides of the storage unit, which may have two sets of movable elements, a line of characters being recorded on one set at the same time as a line of characters previously recorded on the other set is decoded by the reading carriage. The widths of the characters may be totalled by a counter, and means are provided whereby an erroneously recorded character can be removed and replaced by a correct one, the width of the erroneous character being subtracted from the width total and the width of the correct character being added thereto. The register is particularly applicable to photographic type-composing machines of the kind described in Specifications 669,531 and 669,556, which have a keyboard operating bars which impress characters on paper in the manner of an ordinary typewriter, and also complete a number of electric circuits in accordance with a code in which each character corresponds to a different combination of circuits. Each energized circuit operates one of the rocking plates RP1-RP7, Fig. 1; as illustrated, plates RP2, RP4, RP6 are operated and move forward the corresponding hammers of a set of hammers M1-M7 slidable in plates 110, 111 of a unit EM and returned by spring action. A register unit EB comprises plates 100, 101 and is movable horizontally with the typewriter carriage and vertically between two positions. A number of pins slidable in plates 100, 101 are arranged in columns, each column having a set of pins B1-B7 alternating with a second set B<SP>1</SP>1-B<SP>1</SP>7. Each time a key is depressed, unit EB moves to bring the next column of pins opposite the hammers M1-M7. The hammers push in the selected pins of the set B1-B7 when unit EB is in its lower position, and of the set B<SP>1</SP>1-B<SP>1</SP>7 in its upper position. The first four pins are used to express the width of the character in a binary code, and as the characters are registered their widths are added up by a binary counter, e.g. as described in Speci. fication 691,738. While one line is being registered, the previously registered line is being decoded by a decoding unit EX which has a back plate travelling on wheels 107 on rails 108 on which slides a bar 104 in brackets 105. Bar 104 carries eight rocker members P1-P8, pivoted on brackets 115. At each movement of unit EB, a rocking-plate 109 is operated electromagnetically to raise bar 104. The pins which project as a result of the registration of the previous line lie in the path of members P1-P8, which are thus rocked and close pairs of contacts C1-C8, closing circuits for selecting the character to be photographed. The upper seven rocker members and contacts are actuated in decoding one line; for the next line the unit EB moves into its alternative position and the lower seven rocker members and contacts are used, and so on. The leads from the contacts C1-C8 to the decoder are switched according to the position of unit EB. A faulty character may be erased, and replaced by a correct one, at any time during composition of the line. The typewriter carriage is first moved to bring the faulty character into printing position. This also brings the corresponding combination of pins opposite the hammers M1-M7. A correction switch COK (Fig. 3) is then closed, applying an impulse to an electromagnet EM, controlling a stepping switch having five positions and four levels A, H, F, G. A cam Ca closes a switch at a rate of, e.g., four times per second, to apply impulses to the brushes. These impulses are applied through terminals 1, 2, 3, 4 of level A (which are all connected together) to the electromagnet EM, so that once the switch is started it will be stepped through all its positions until the brushes reach terminal 0 in each level again. In position 2 an impulse through level H energizes an electromagnet COC, operating pivoted lever Y3 to raise a sliding bar OP carrying four levers Y which are rocked by the pins which represent the character width and which have been pushed out. Levers Y, when rocked, open contacts Y8. Also in position 2, an impulse is sent to the counter CP, in which the total line length is accumulated, through level G so reversing the positions of the counter elements as explained in Specification 691,738. In position 3, electromagnet COC remains energized and an impulse is sent through the closed contacts Y8 to the counter CP, adding to it the width of the faulty character. Since in position 4 the counter elements are again reversed, the result is to subtract from the counter total the width of the faulty character. The combination is removed by a sliding member Y5, having arms with hooks engaging cutout portions of the pins. On position 4 an electromagnet EF is energized to operate member Y5, which pulls out all the pins. The key for the correct character is then struck, overprinting the faulty character in the typewriter carriage, pushing in the required combination of pins, and adding the width of the correct character to the total of the counter CP.