Patent GB-998909-A (GB)
Title: Printing apparatus
IPC: B41J7/48
Filed: 1964-05-21
Abstract: 998,909. Selective - printing apparatus. INTERNATIONAL BUSINESS MACHINES CORPORATION. May 21, 1964 [May 27, 1963], No. 20944/64. Heading B6F. A printing apparatus, particularly for printing on steel products 58, Fig. 1, includes at least one type-wheel 86 carrying a number of radially movable type plates, a coaxial rotating disc 22 mounted within the wheel and having on it code-sensing devices representing each type plate, means for releasably coupling the wheel and disc, and selection means situated within the wheel co-operating with the sensing devices and controlled by the relative angular positions of the wheel and disc, to move a selected plate outwardly to an operative printing position. As shown, there are three typewheels 86, each associated with a disc 22, the discs 22 being fixed to a constantly rotating shaft 20 and the typewheels 86 being free on the shaft but normally coupled to their respective discs 22 to rotate therewith by inter-engaging balls 66 and sockets 46, Fig. 1. Each typewheel 86 is cup-shaped and carries on its periphery ten type-plates 0 . . . 9, carrying, e.g. the numerals 0 . . . 9, the plates being radially slidable but normally held within the periphery of the wheel by springs 88a. Each plate has on its inner face a channel-shaped member 88, and the disc 22 has a cam roller 44 which by engagement with a member 88 moves the corresponding type-plate radially outwards into a printing position, in which position it is inked by a roller 37 during its rotation. Inside the wheel and adjacent to where the plates 0, 1 meet, is a lug 90, and when an electromagnet 94 is operated, a pin 92a is moved into the path of the lug 90 to stop the rotation of the wheel at a fixed reference position. In this position, a cam on the lug 90 closes a switch 39, Fig. 3, (not shown), connected by lines 61 to and closing a switch 60. On the disc 22 are ten radial rows 24 . . . 33 of switch-operating cams, each row comprising a combination of one to four cams representing in code one of the numbers to be printed and an outer cam spaced slightly rearwardly from the others. The cams act upon five switches 98a . . . 98e connected to current supply and fixed to a frame 21 carrying the printing assembly, the switches being connected via the switch 60 to a gate 49. The switch 98e, operated by the outer cam causes the signals from the other switches to be gated into a comparator 48, its slightly later operation allowing for delay in the closing of the other switches. Selection is effected by a four-unit binary code plus an additional signal produced by a device 47 which may be a computer or a keyboard device. When the device 47 operates, the code signals pass to the comparator 48 and the additional signal closes a switch 51 to electromagnet 94, causing the typewheel to be stopped in its reference position by the engagement of parts 90, 92a, and switch 60 to be closed. The disc 22 continues to rotate until one of the sets of radial cams 24. . . 33 corresponding to the signals from the input device 47 and to a number, e.g. numeral 6, to be printed engage switches 98a . . . 98e. In this position, cam roller 44 moves type plate 6 outwardly. The comparator 48 now supplies a signal of finite duration to open switch 51 and free the type wheel for rotation with its disc 22, and also to operate a delay circuit 50. The circuit 50 opens switch 60 and, after a delay equal, e.g. to one rotation of the type wheel, closes the circuit of a solenoid 54 mounted on the support bracket 21, and the plunger 56 of which is fixed. Energization of the solenoid 54 causes the typewheel assembly to be moved downwardly to effect printing. Each typewheel is set separately in the manner described. The solenoid 54 may, however, be connected to a control station so that the time of printing may be operator-controlled. Instead of the ball-and-socket devices for coupling a typewheel and its disc, coupling means controlled by the member 92 (Fig. 3, not shown), carrying the stop pin 92a may be provided.