Patent GB-890218-A (GB)
Title: A printing mechanism for printing office machines
IPC: B41J1/20
Filed: 1958-07-23
Abstract: 890,218. Selective printing. OLYMPIA WERKE AG. July 23, 1958 [Jan. 21, 1958], No. 23720/58. Class 100(4) [Also in Group XIX] Type-band machines. A high-speed printing mechanism, for e.g. use with calculating machines, is supplied with data from a storage device and is controlled by electronic means so that a series of type members which move along a line of printing are selectively actuated whenever a particular digit is in position in which that digit is required. The type-members are arranged for moving on an endless track 13 and movement of one set of type-members through printing position completes one line of printing from the storage device. As shown in Fig. 2, the type-members are formed on tongues 17 of a steel band 16 which is driven by pulleys 19, 19<SP>1</SP> from a motor 25. A modification, Fig. 5, shows the type-memebers 17 on tongues 18 which are attached to or form part of a chain drive 38. Alternatively (Fig. 66 not shown), the tongues may be embedded in a resilient synthetic resin band formed with teeth for silent driving engagement with gears. Type sliding in stationary frames. As shown in Figs. 8, 8a, 8c, separate typemembers 60 are driven by gears 56, 57 around stationary guide channel 58 and at appropriatemoment, when a desired digit is in correct columnar position, an electromagnetically operated hammer is actuated. Operation. Data to be printed is stored on a drum in the calculating machine, in the form of word pulses d, Fig. 9, together with clock pulses a and trackbeginning pulses c. When printing is required a "print" instruction b is sent to a control device, connected to the printing mechanism and to a decoder which converts incoming digits in the form of the excess-three code into decimal digits. The decimal digits from the decoder are passed through amplifiers A16, A25, Fig. 13, to the horizontal lines of a matrix store. At the same time a pulse el arrives at the decoder circuits, (Fig. 12 not shown), and steps a ring counter 80 one step, i.e. from S 1  to S 2 . This step provides a pulse f 2  and after passing amplifiers A26, A46 reaches, as f <SP>11</SP> 2 , e.g. the intersection 85 where the decimal digit 7 (or equivalent code C) entered by the horizontal line, is stored. A fresh four-unit signal is then dealt with after the flip-flop circuits have been restored. The ring counter 80 is stepped to S3 and the next signal is stored by pulse f<SP>11</SP>3. The output system for the storage matrix is shown in Fig. 14 and comprises monostable flip-flop circuits F12-F32, amplifiers A67 -A87 and hammer-driving magnets M1-M21 opposite the type-members to be printed. Stepping switches Sl and S<SP>1</SP>1 and rotary switch 31a which rotate in sympathy with the typemembers ensures that output from the matrix occurs in the correct position. A photo electric cell 35, Fig. 2, is arranged to be actuated from a light 36 each time a duplicate set of type-members makes one step, so that pulses are generated as the first set of type-members are passing along the printing line. These pulses il, often passing through a rotary switch 31 and circuits in the printer, arrive as i3 at diode d1-d20 the second connections of which are connected to the sliding contacts of the rotary switch 30. If for example a digit 3 is stored as indicated at 87 a pulse now arriving, on diagonal conductor D and now extinguishes the associated thyratron which was ignited during the storage, and in so doing transmits a reading pulse K18 to a flip-flop circuit F29 and a digit 3 is printed. Instead of using a storage matrix consisting of cold cathode thyratrons it may comprise magnetic cores.