Patent GB-967193-A (GB)
Title: Apparatus for decoding and printing digital data
IPC: B41J7/48
Filed: 1961-01-17
Abstract: 967,193. Selective signalling systems. SOC. LAMY D'ETUDES ET DE RECHERCHES. Jan. 17, 1961 [Jan. 22, 1960; Dec. 12, 1960], No. 1923/61. Heading G4H. [Also in Division B6] In apparatus for decoding, and printing the decimal equivalent, of binary-coded data, a print wheel is mounted on an arm which is pivoted about a fixed axis so as to assume either a position in which a drive mechanism for the print wheel is engaged, or a position in which the print wheel is latched, and the period for which an electromagnet is energized determines the time for which the drive is engaged. In one embodiment, Fig. 2, the print wheel 6 rotates on a shaft carried by an arm 2 which pivots about a shaft 3. When electromagnet 11 is energized, arm 2 pivots so that drive wheel 9 engages wheel 1 and rotates print wheel 6 until magnet 11 is again de-energized, whereupon spring 14 raises arm 2 so that wheel 1 meshes with reset wheel 7 which at this time is stationary. The printing action then takes place by a mechanism not shown in Fig. 2, cam 17 which is driven from the input shaft of the apparatus slightly depresses arm 2 so that wheels 1, 7 are partially dis - engaged, reset wheel 7 is then rotated and returns wheel 1 to the zero position in which a projection 45 abuts against a projection 46 on arm 2 and a pair of chamfered teeth on wheel 1 allow free rotation of wheel 7. The apparatus is thus reset for the next cycle. Fig. 6 shows a circuit for controlling a number of electromagnets 11-11<SP>5</SP>. Each set of switches 67-70 is set according to the data to be decoded, the switches when closed representing 1, 2, 4, 8 respectively. Cam switches 60-63 supply pulses of 1, 2, 4, 8 units duration to the corresponding groups of switches 67-67<SP>5</SP> to 70-70<SP>5</SP> in such time relationship to each other that each electromagnet may be energized for any one of nine discrete periods. In another embodiment, Fig. 8, at the start of a printing cycle, the uncut teeth 5<SP>1</SP> c  of wheel 1 and 7<SP>1</SP>d of wheel 7<SP>1</SP> co-operate to hold arm 2<SP>1</SP> in a raised or "latched" position, and electromagnet 11 is energized to maintain this position when drive wheel 7<SP>1</SP> starts to rotate. As soon as electromagnet 11 is de-energized, spring 14 causes wheel 1 to mesh with the drive teeth 7<SP>1</SP>c, the type wheel being rotated until the printing position is reached, at which tooth 7<SP>1</SP>b engages wheel 1 and the rotation of shaft 8 is interrupted. After the printing operation shaft 8 again rotates and wheel 1 is rotated further by reset teeth 7<SP>1</SP>a of wheel 7<SP>1</SP> When wheel 1 reaches its zero position uncut tooth 5<SP>1</SP>c co-operates with teeth 7<SP>1</SP>a, and since meshing engagement is not possible, wheel 1 is pushed away and is latched by a tooth 5<SP>1</SP>a abutting against a projection 4<SP>1</SP>a and a spring leaf 107 which engages another tooth. Wheel 7 is rotated until uncut tooth 7<SP>1</SP>d abuts against tooth 5<SP>1</SP>c. Electromagnet 11 is re-energized at the start of the next cycle, but does not exert sufficient force to overcome the bias exerted by spring 14. The control circuit for electromagnet 11 is similar to that shown in Fig. 6.