Patent GB-923256-A (GB)
Title: An apparatus including a member which moves to an extent dictated by an electrical signal supplied to the apparatus and representing a digit
IPC: H04L17/26
Filed: 1960-05-30
Abstract: 923,256. Selective printing. HARRISON REPRODUCTION EQUIPMENT Ltd., and R. FIRTH. May 30, 1961 [May 30, 1960], No. 19097/60. Class 100 (4). [Also in Group XXXVIII] In an apparatus including a member 14 which moves to an extent dictated by an electric signal and representing a digit, a number of electrical coils or electromagnets 11 with armatures are provided, each associated with one of a number of digits, and each energized to the exclusion of the others when an electric signal representing the digit is applied so that the corresponding armature 13 is projected, the projecting armature serving as a stop to arrest the movement of the member 14 at a position characteristic of the digit. As shown, in apparatus for printing one of the digits 0 ... 9, the member 14 is a strip guided by posts 15 and has a transverse slot 17 engaged by a pin 18 on a lever 19 pivoted at 20. To oscillate the lever 19 and thus move the member 14 across the face 11B of the coils, a solenoid 37 is provided, the spring-projected armature 38 of which is connected at 40 to a U-shaped member 39 in which is slidable a head 41 attached to a rod 42 pivoted to the lever 19. A compression spring 44 is interposed between the head 41 and the closed end of the member 39. Energization of the solenoid 37 causes rightward movement of the member 14 until its end abuts against an armature 13 to arrest its movement, the armature 38 and member 39, however, continuing to move to the left and thus further compressing spring 44. Ten coils with armatures 13 are provided at 11, the coils from left to right being energised by signals representing the numerals 0 . . . 9 in that order. Links 25 pivoted at 20 carry rotatably at their upper ends a head 28 on the curved face 32 of which are type faces of the numerals 0 .. 9 with the 0 face at the top. Links 36 connect the head 28 to the lever 19 so that following a move-  ment of the member 14 determined by a particular armature 13, the head is rotated so that the type face corresponding to the movement is positioned opposite a platen 35 for printing. The links 25 have holes 49 engaged by smaller pins 48 on levers 21 pivoted at 20 and connected to the spring-projected armature 46 of a solenoid 45. Energization of the solenoid 46 first moves the levers 21 in a clockwise direction to bring a tooth 22 carried thereby into engagement with teeth 30 on the head to lock the head in set position, and then causes combined movement of the levers 21 and 25 to cause the type face to print, through an interposed ink-ribbon, on paper 33 passing around the platen 35. If no solenoid 13 is projected during movement of the member 14, the latter and the head 28 move to their maximum extent in which position the head prints a " ? " mark. For printing a number comprising more than one digit, several sets of apparatus as described equal in number to the number of digits are assembled side-by-side; the devices 37 . . . 42 may be common to all the sets. In modifications, the operative ends of the armatures could be arranged on a circular arc and the member 14 given a rotary movement. Further the turning movement of the lever 19 could be used to cause movement of a strip connected thereto in the same nanner as the link 36 and having characters thereon for printing. The solenoids in the assembly 11 can be mounted in bores in a block, open ends of the bores facing the top 11A and bottom 11B of the block alternately (Fig. 1 (Complete), not shown), all the ends of the armatures 13 being situated at the bottom. 11B of the block. Signals for energizing the solenoids 11 are derived from a shaft encoder (see Group XXXVIII) comprising a disc rotated through an angle corresponding to the digit concerned and carrying conductive and non-conductive segments engaged by four brushes connected to four relays. Energization of one or more of the relays throws over corresponding switches so as to energize one only of the coils 11 and cause operation of the printer. Specification 809,679 is referred to.