Patent GB-1133168-A (GB)
Title: A high speed selective printing mechanism
IPC: B41J7/64
Filed: 1967-04-11
Abstract: 1,133,168. Selective printing. NATIONAL CASH REGISTER CO. 11 April, 1967 [18 April, 1966], No, 16433/67. Heading B6F. Type-wheel machines.-A printing mechanism, for example printing on the edge of punch cards 48, Fig. 8, comprises a rotary typecarrier 36, rotatively carrying a plurality of type-wheels, the type-carrier and the typewheels being separately driven by first and second driving mechanisms 50 to selectively position a character in printing position, the drive mechanisms being operatively attached to first and second belts 54, 56 which each extend over a series of cam pulleys and around the drive members to selectively rotate the type-carrier 36 and the type-wheels. Type-wheel construction.-Each type -wheel comprises an octagonal rim and sleeve, Fig. 8, rotatively mounted on a stub 228 by a screw 238. The stubs 228 are concentrically mounted on the carrier 36 so that a sun gear 44 may simultaneously rotate all type-wheels by means of teeth 40 on the type-wheel sleeves. Selection action; combination and aggregate movement mechanism.-The type-carrier is positively and selectively rotated by the first drive mechanism 50 which includes three electromagnets 116, Fig. 2, three clutch mechanisms 74, 76, 78, three double eccentrically mounted pulley cams 148, 149, Fig. 4, and a belt 54 which is fixed at either end to the side plate 22 by clamps e.g. 188. One end 54a extends over each of the three pulley cams carried on shafts 68, 70, 72 and over a drive pulley 38, Fig. 1, rotating a gear 208, and a gear 210 on the type carrier 36. The other end 54b extends over the other section of the double pulley cams to its clamp on the side plate 22. The pulley cams 148, 149 are selectively rotated 180 degrees about their shafts 68, 70, 72 by the operation of the clutch mechanisms, of the expanding helical spring kind, controlled by Y- shaped members 104, Fig. 4, operated by electromagnets 116. The rotation of the typewheels on the carrier is effected by the second drive mechanism 50 in a similar manner, either separately or simultaneously with the rotation of the type-carrier itself. The pulley shafts 68 70, 72 are abruptly stopped and rebound prevented by spring latches (180) and cams (176) as shown in (Fig. 3). In the embodiment described type-carrier may be moved into one of six different positions, the combination effect of the three pulleys and similarly the typewheels may be moved into any one of eight positions. Electrical operation.-The type-selection is effected from signals from a computer or punched cards and appropriate electromagnets 116 (Fig. 11) are operated, diodes being provided when the selection mechanism requires more than one magnet to be operated. A time delay ensures that the magnets remain operative until the next signal is received so that the type-carrier and type-wheels do not return to "home-position" but go direct to the new position whichever way this may mean. Each electromagnet 116 has a resistance (252) in series with the operation coil which comes into circuit after the magnet has operated to reduce the operating current to one sufficient to only hold the magnet. Dual function.-The machine may also perforate the card 48 by means of punches 247.