GB1262727A - Improvements in or relating to type-printing devices - Google Patents

Abstract

1,262,727. Electric selective signalling. SIEMENS A.G. 19 Dec., 1969 [20 Dec., 1968], No. 61913/69. Heading G4H. [Also in Division B6] A printer printing one character at a time from type spaced around the circumference of a wheel has, on a shaft geared to the shaft carrying the type wheel, impulse wheels which generate character timing pulses and a synchronizing pulse marking the beginning of the cycle of characters on the type wheel. Two impulse wheels generate the character timing pulses and are mechanically involved in operating the print hammer. In Fig. 1 a wheel 5 bearing type on its circumference rotates on a shaft to which is geared a second shaft carrying two impulse wheels 7, 8 and a further triangular impulse wheel 18 which are sensed by inductive sensors 15, 16 as shown, or alternatively by photoelectric sensors. The two impulse wheels 7, 8 have teeth which are staggered by half a twopitch between the two wheels and combine to produce a timing pulse as each character passes over the print hammer 13. The phase of these timing pulses can be adjusted by movement of the sensor 15 on pivoted arm 20, sensor 16 being adjusted simultaneously. The print hammer 13 is operated by either relay 9 or 10 injecting a rod 11 or 12 into the path of an impulse wheel tooth which deflects the rod downwards and operates the print hammer. Two impulse wheels and rods are provided because the time to operate one rod is greater than the time for wheel 5 to move one character position. The impulse wheels rotate at 2/3 the-rate of the type wheel 5 and to mark the beginning of the cycle of type characters in the timing pulse chain a triangular wheel 18 generates by sensor 16 synchronizing pulses, every other one of which is blanked off by means of sensor 17 and wheel 19.