DE2063189A1 - Control device for serial printer - Google Patents

Description

206318a

Dr. Walter Layoff Munich, December 22nd, 1970

Godfather π ι a η \: old My reference: 68 - 786

f .: ίϊ;: c h ο »8 1

Wissniaiinstrasse 14

Description of the company's patent application

Burroughs Corporation, Second Avenue at Burroughs, Detroit, Michigan 48232, U ₀ S ₀ A,

concerning

Control device for serial printer

The invention relates to a control device for fast se- * printer.

Fast series printers are used in many areas, for example in connection with electronic computers, electronic «see desktop computers and the like ,, Some of the known fast Druckei ¹ vioisen to a continuously rotating drum, chain or a belt on which the printing types befindenο Derar" term Printers are known to have two stop hammer arrangements o They either have a number of stop hammers, where "in Hamner ftyr each type identification is present in one line, or there is a single hammer that is moved from character to character along the printing line"

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In the case of the last-mentioned type of serial printer, the transport mechanism for moving the stop hammer along the pressure cell forms a threaded spindle, as is customary in tape printers, or a toothed belt. A detailed description of the mode of operation of a high-speed serial printer with a toothed belt transport mechanism can be found in US Pat. _{No. 0 3,472,352ο}

In the case of high-speed printers with a single stop hammer and a rotating drum, a or several clock signals are required to keep the drum rotating, to coordinate the movement of the hammer and the flow of data from the ™ central data processing system »It is Firstly, there are signals to initiate the movement of the hammer and the carrier at the beginning of each print line, two- » at least about the display signal for the position of the print hammer along a print line, and thirdly for the signal for triggering the Pressure movement of the hammer, causing the paper against the Drum is pressed ,, These signals ensure correct operation of the quick release button »

In known high-speed printers, an initial signal for each goes from the central data processing system or the data source Pressure cell off, and this signal causes the drum and fe to set the hammer and the associated parts in motion and drive the conveyor belt. However, if the angular position of the drum changes slightly, the timing coincidence goes lost between the drum and the stop hammer

In high-speed printers of the type mentioned synchronous running between the drum and striking hammer, however it must be ensured so that the correct character is printed _o For this purpose, rotating clock signal provided "slices in the known high-speed printers, which have teeth, which mark the

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at the periphery of the drum corresponding to ₀ The teeth work with a converter together and generate pulses representative of the angular position of the drum Sindo These pulses go to the one input of a comparator whose other input is fed by the central data processing system and to druk- ¹ kende signal leads. If these two input signals match, a corresponding signal is emitted from the comparator and the hammer is actuated so that the relevant character is printed. After printing, a different tooth spacing can be used to reset the comparator. In a control device of this type, as described _{in US Pat. No. 0} 3,117,51t, μ any deviation in the speed of the drum leads to an impairment of the precise timing pulse output, as is required in the case of an irregular tooth spacing o

To overcome this problem, two ways have been proposed, namely the use of two clock signal slices, which each have their own converter, or the use of a single clock signal slice with two converters, a control device with a single clock signal slice and two transducers is described in U.S. Patent No. 3,291,909 Such control devices require two circuit branches, for example two converters with the associated amplifier circuits

The invention is based on the object of creating a control device for high-speed printers which provides improved synchronization with less circuitry, regardless of the starting position of the printing drum

The invention is based on a control device for a High-speed serial printer with a rotatable one having the printing types Printing drum, a hammer mounted on a hammer support, the hammer support being in a rest position,

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and with a device for continuous transport of the hammer carrier along a print line parallel to the axis of the drum and solves the problem posed by a clock device coupled to the drum for the synchronous drive of the same, by a transducer having two probe ends for removing clock markings from the clock device, by one of the Signals of the first key end controlled coupling device for coupling the hammer carrier with a transport device for the same, and by a triggering device controlled by the second key end for actuating the stop hammer in the correct angular position of the drum in relation to the print line "

w The invention is hereinafter described based additionally see matic drawings of an exemplary embodiment

Fig. 1 is a perspective view of a high-speed serial printer with a control device according to the invention;

Figc 2 shows a clock device with two clock disks,

a transducer having two sampling points and the associated circuit;

Figure 3 is a block diagram of the logic circuit

for demodulating the signals output by the converter;

HA-4C shows circuit diagrams of part of the logic ^ Circuit of Fig «, 3, and

FIGS. 5A-5G show graphs of the pulses _{or the like occurring at different points in the circuit}

The high-speed printer 11 shown in FIG. ₀ 1 comprises a printing drum 13, a single stop hammer 15, a hammer transport belt 17 and two timing disks 19 and 21. The drum 13 is rotatably mounted on a shaft 23. A hammer carrier 25 is located in front of the drum , the hammer 15 along a print line 27 parallel to the axes of the drum 13 and shaft

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23 moved to

The drum is driven by an electric motor 29 via a toothed belt 31 continuously driven so that the printing types on the circumference the drum passed the print line 27 «Die Drucktypen, the ZoB. Include letters, numbers, and any symbols can (in the following summarized under the designation "characters") ' are arranged on the circumference of the drum in rows, which are parallel to the axis of the drum, as well as in lines, which extend around the drum. The lines lie at a distance from one another so that there is enough time for the stop hammer 15 to be withdrawn after a character has been printed. The printed characters are arranged so that the | Characters in each column lie in a predetermined sequence and this sequence is present twice in each column, with between ~ see both episodes there is a free space in between the printed characters in each column are oriented in such a way that with a certain Time the same characters appear in each column along print line 27.

The stop hammer 15 is pivotably mounted on the Hammerträf 25 and preloaded away from the drum 13. The stop hammer is actuated by a solenoid 33, which makes it bounce against the paper 35 and the drum 13 = the characters in a print line are the line of right to left * printed ₀

On the right side of the high-speed printer 11 and at right angles to the shaft 23 there is a roller 37 which is driven synchronously with the drum 13 by the electric motor 29. At the end of the shaft 37 is a drive pulley sits 39, while a guide disc »ti on is the left side of the printer is arranged to the axes of these two wheels are positioned horizontally _o around the pulleys

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39 and 41 an endless drive belt 17 is placed over the Shaft 37 and the drive pulley 39 is driven counterclockwise.

There is a coupling device 43 is provided, which is a solenoid 45 for actuating the clutch and which is attached to the urinary » merträger 25 is attached »When energizing the solenoid 45 engages the coupling 43 to the teeth of the toothed belt 17, and the an · » The hammer and hammers are lengthways from right to left of the print line 27 moved. The hammer carrier 25 is biased by a spring 47 into the rest position, which is the outer right end the print line 27 forms »

On one end of the shaft 23 there is a timing disk 19 with a row of magnetic flux-conducting teeth 49 on the circumference. The teeth correspond to the positions of the different types of printing on the circumference of the drum 13 appropriate gaps _o The use and mode of action of these rows of teeth is described below.,

At the right end of the shaft 23 sits a bevel gear 51, which with a fe bevel gear 55 is engaged, which is attached to the front end of a shaft 53, the right of the shaft 23 and at right angles is attached to the high-speed printer 11 for this purpose. The timing disc 21 controlling the transport is rotatable on the rear side This timing disk is attached to the shaft 53 and has a single magnetically conductive projection 63. When the drum 13 is moved by the motor 29, the timing disc 19 and the transport timing disc rotate 21 synchronized with this "

Between the two timing disks 19 and 21 there is a Converter 57 with two sensing points, the front sensing point 59 of the

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Converter works together rait the teeth «* 9» of the clock disk 19, and the rear sensing point 61 of the transducer 57 cooperates with the projection 63 of the transport clock disk 21 together "

The structure of the transducer is shown in Fig. 2 the front and rear sensing points 59 and 61 are two pole pieces made of ferromagnetic Material. In between there is a ceramic permanent magnet 65 in contact with both pole pieces. To diesel » A coil 67 is also wound beneath it, with a constant Winding sense The two sensing points of the converter are therefore connected in series »That one end of the coil 67 is grounded and the other end is connected via a line 71 to a control circuit 69 · However, both ends of the" Winding 67 can be connected to the control circuit 69 as if the coil formed the secondary winding of a transformer.

The control circuit 69 comprises a phase demodulator 73, a comparator 75 with two inputs, a data source 77, an AND gate 79 with three inputs and a controllable silicon rectifier 81 and furthermore via a line 85 to one of the three inputs of the AND gate 79. The output of the data source 77 is connected via the line 87 to the second input of the comparator 75, and furthermore via the line 89 to the second input of the AND -Gatters ä 79.

When the hammer carrier 25 is in its rest position, the magnetic shunt 91 cannot enter the flux path between reach the magnet 93 and the magnetic switch 95 so that it is closed. The magnetic switch 95 is via the line 96 connected to the third input of the AND gate 79. The AND gate 79 is therefore only released when the switch 95 is closed »As soon as the hammer carrier 25 is moving longitudinally

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the print line 27 begins, the shunt 91 moves between the magnates S3 and the switch 95 and opens the same » so that the switching state of AND gate 79 is interrupted "

The output of the AND gate 79 is connected to the control grid of the silicon rectifier 81 "its cathode is grounded" and the anode forms the output and is in turn connected to a switch-off timer 97. The output of the same leads via a line 98 to the clutch actuation solenoid 45. If the AND gate 79 is enabled, the output of the same controls the rectifier 81. The output signal of this rectifier A in turn energizes the solenoid 45 via the line 98, so that the Clutch 43 attacked the toothed belt 17 Since an input of the AND gate 79 only carries a signal when the switch 95 is closed, the clutch can only be excited when the hammer carrier 25 is in its rest position Timer 97 controls rectifier 81 and de-energizes solenoid 45. The coupling 43 therefore falls off and uncouples the toothed belt 17, the spring 47 tonguing the hammer carrier back into the rest position _{or the like}

The comparator 75 has a conventional logical structure, see above that an output signal occurs only when both input "signals match". One input of the comparator 75. \ is P the character to be printed, which is transmitted via line 87 from the data « quelle 77 comes, and the other input corresponds to the mark on the drum at the printing point (derived from the teeth 49 via the demodulator 73 and the line 83) “The output of the Comparator 75 is connected via line 99 to one input of a two-input AND gate 101 "the other." Input 111 of the same carries an inverted signal. The output of switch 95 is via line 113 with the inverted signal Branch 111 of AND gate 101 connected. The AND gate 101

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therefore shows the presence of a signal on comparator 75 at open switch 95 to “As already mentioned above, means the open state of the switch 95 that the hammer carrier is is not in its rest position, but through the toothed belt 17 is moved along the print line 27. When the AND gate 101 is turned on, the output of the same activates via the line 115 the stop hammer solenoid 33, which the stop hammer 15 actuated »

₀ 3 shows the logic circuit of the phase demodulator 73 "This comprises a differential amplifier 117 with two outputs A and B, the output A is connected to a driver amplifier 119." which in turn is connected to an AC coupled timer circuit 121. The output of the same is connected to one input each of the AND gates 123 and 125

The output B of the differential amplifier 117 is connected to a first Inverter 127 connected The output of the same leads over a diode 129, the anode of which is connected to the inverter 127, to a second inverter 131. The junction between Diode 129 and inverter 131 are connected to one end of a capacitor 133, the other end of which is negatively biased ο the output of the second inverter 131 X3t is connected to one Input of AND gate 123 switched on. The output of the same is connected to the input of a third inverter 135 Output again with the second input, the AND gate 125 in f Connection is »

Since oin magnetic transducer is responsive to flux changes,-Bpricht ent the output voltage of the magnetic Wandlere the first derivative of the relevant mass in front of a pole piece of the transducer "When a tooth ¹ 19 of the Taktschcibc 19 past passes in front of the front sensing end 59, is the slew rate of the output voltage of the VJandlors to positive on the leading edge, zero in the middle and negative on the trailing edge. When the protrusion 63

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Ί _Μ

passes the rear end of the key Sl, an output ** is created wave with reversed polarity, since the projection passes the opposite pole piece of the transducer and since both pole pieces are arranged in series and wound in the same direction. the The output voltage is negative at the front edge, zero in the middle and positive at the rear edge. This gives see rules out of the spring

The various circuit components of the logic circuit according to. Figo 3 are known per se. »For a precise explanation of the mode of operation, however, some circuit components are shown» Figo shows the differential amplifier 117. The two inputs can be connected to the converter 57 via a transformer «However, both ends of the winding can also be be connected to 67 instead of erdenο an end of winding the two PNP transistors with their base electrodes via equal resistors R ₁ of 1000 0hm to a negative bias voltage of Va = lHvoltangeschlossen. The emitters of the transistors are • connected to one another and connected to a negative voltage V "= 28 volts" via a resistor R "of 5100 ohms". The collector of each transistor is _{grounded via a resistor R 3} of 6200 ohms, and the amplifier outputs are from removed from the two collectors

The driver amplifier 119 only effects pulse shaping *: ' of the output voltages of the output A of the differential amplifier kers and has no meaning for the logical circuit structure.

4B shows a typical inverter as it can be used for inverters 127, 131 and 135. The input of an inverter is connected to the _{base of a PNP transistor via a resistor R 1} ^ of 30 kß with the base of a PNP transistor. The base is also connected via a resistor R ₅ of 270 kß to a negative voltage "-V ₂ , and the emitter of the transistor is connected to a negative bias voltage -V., _o The collector of the transistor

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is grounded through a resistor R ₂ and serves as the output of the circuit.

UC shows an alternating voltage coupled timer circuit 121. The input of the same is connected to the base of a PNP transistor via a coupling capacitor C of 170 pF and a resistor Rg of 2 kΩ. The input is also via an equal resistor R _g with a negative voltage -V. tied together. The junction of the capacitor C and the resistor R _c leading to the base is grounded via a resistor R ₇ of k7 kü. The emitter of the transistor is grounded and the collector of the transistor is _{also grounded through a resistor R 2} and serves as the output of the timer circuit.

The signals at various points in the circuit according to FIGS. 2, 3 and 5 are explained in more detail below Form of the output signals of the timer circuit 121, wherein by comparing the. It can be seen from FIGS. 5A and SB that the timer circuit generates an output pulse when a negative signal occurs at the output of the differential amplifier. Fig. 5D shows the waveform of the output voltage at the output B of the differential amplifier 117, and FIGS SE, 5F and SG show the output pulses to the invertors 127, 131 and 135. When an inverter (eg 135) g turned off, outputs the output signal the same free the circuit fed by this, for example the AND gate 125.

In the idle state t, the differential amplifier 117 is biased so that that the driver amplifier 119 is turned off and the inverter 127 is turned on. The driver amplifier 119 stops the timer circuit 121 is turned off, so that both AND gates 123 and 125 are disabled. The inverter 127 keeps switched on State the inverter 131 is switched off and this

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in turn, the inverter past reaches 135 then is switched as soon as a tooth H9 front of the pole piece 59 of the transducer 57, an output signal is produced (Fig. SB, 5D) on the differential amplifier ₀ This output turns on the inverter 127 (Figo 5E) from, charges the capacitor 133, switches the inverter 131 (Fig. SF) on and the inverter 135 (Fig. 5G) abo These processes are present, for example, in Fig. at time t

As soon as the center of this tooth has passed the transducer, i.e. at time t _2J . switches on the inverter 127, but the charge on the capacitor 133 causes a delay which leaves the inverter 131 switched on, so that the inverter 135 also remains switched off Timer circuit 121 triggerto This is of the usual design and responds to negative edges of a pulse and generates an output signal in the process. This is used to enable gates 123 and 125 «

At time t ₂ , when an output signal is generated by the timer circuit 121, the inverters 127 and 135 are switched off and the inverter 131 is switched on. The latter therefore blocks the AND gate 123. As a result, no signal on the line 85 can go to the AND gate 79 arrive so that the hammer carrier 25 is not caught by the drive belt. "However, since the inverter 135 is switched off, the AND gate 125 is in the switched-through position". Therefore, a signal can reach the comparator 75 via the line 83 "Logically seen the purpose of capacitor 133 is to "memory" that inverter 127 was turned off and turned on again just before the timer circuit was triggered "

At time t ₃ , when the capacitor 133 is discharged, the inverter 131 is switched off and the inverter 135 is switched on »

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The logic circuit is in the same state as at time t, so that the next pulse can be processed »

When the protrusion 63 passes the opposite pole piece B1 of the transducer 57, a wave of reversed polarity becomes generated. This begins at time t ^ o The timer circuit 121 is in turn from the negative edges of the signal wave triggers and controls AND gates 123 and 125 »Die negative bias of the amplifier keeps the inverter 127 on, so that the inverter 131 is turned off and the inverter 135 is on. The latter therefore blocks the AND gate 125 and prevents an output signal on line 83 reaches an input of the comparator 75 'However, since the inverter 131 is switched off, the UHD gate' 123 is enabled; and the output signal on the line 85 enables the hammer carrier 25 to be coupled to the conveyor belt 17.

When the center of the projection 63 passes the pole piece (at time tg), the inverter 127 is switched off and the capacitor 133 is charged, but the timer circuit does not trigger until a new tooth (or projection) passes a pole piece. The delay in charging the capacitor until time t _{g }} when the idle state is reached therefore does not affect the output signals of the gates 123 or 125.

For a more detailed explanation of the mode of operation, it is assumed that the motor 29 is running and drives the drum 13 via the belt 31. First the print line is started »The hammer carrier 25 is in its extreme right position, i.e. in its rest position between magnet 03 and dome switch 95 «The contacts dos Scarf tors are therefore closed * This is the reason that over the line 98 receives a signal at one of the three inputs of the AND gate 79. A signal from comes over the line 89

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the data source 77 to the second input of the AND gate 79 «, Since a print line is to be started, in contrast to the printing of individual characters, the data source 77 arrives this time no signal via line 87 to the comparator 75.

The rotation of the shaft 23 by the motor 29 also causes the timing disk 19 to rotate so that the teeth 49 pass the pole piece 59 of the transducer 57. A series of output pulses are generated similar to the pulses shown in FIG. 5A. These pulses each enable AND gate 125, since, however, an input to comparator 75 does not carry a signal (due to the lack of an input signal on line 87) , the hammer is not actuated and no character is printed. In addition, actuation of the hammer via the inverted input 111 and the AND gate 101 is excluded 57 a shaft similar to the shaft in Figure 5A * at time t ^ - t _ß, makes the aND gate 123 is enabled and a signal over the line 85 to the aND gate ~ led 79 "As all three a" transitions this aND Gate now carry voltage, the AND gate is released and the silicon rectifier 81 is ignited is actuated and the hammer truck 25 is coupled to the transport belt 17. The hammer carrier therefore begins its movement along a print line 27 from right to left.

As soon as the hammer carrier 25 is engaged with the transport belt has come and is moved along a print line occurs second state in which the characters to be printed by the Data source 77 is fed to comparator 75 via line 87 will. Once the teeth 49 of the timing disk 19 on the pole piece

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59 of the converter 57 pass, the output pulses the same over the line 71 to the phase demodulator 73 ge · » The negative trailing edges of these impulses switch each- » because the AND gate 125 is in the lead state, as before mentioned. Whenever this happens, a signal is passed on line 83 to comparator 75. The comparator gives then, and only then, an output signal on line 79 the one input of the AND gate 101 when both input signals of the comparator are the same. If the hammer carrier 25 with begins its movement from the rest position, the magnetic shunt 91 occurs between the magnet 93 and the switch 95, so that the contacts of the same are opened and the line 113 is interrupted- This state is via the inverting Input 111 passed on to AND gate 101 Comparator 75 sends a corresponding signal via line 99 from "» " is, the AND gate 101 is enabled and it comes in Signal on line 115 to hammer solenoid 33, so that the stop hammer 15 is actuated and presses against the drum 13, whereby the relevant character on the print line 27 is printed.

The line 96 transmits the switching state of the switch 95 to an input of the AND gate 79 and blocks this gate when the switch 95 is open. This prevents forwarded a second control signal to the clutch solenoid 45 as soon as the drive belt is coupled to the carrier 25 for a particular print line. Since the drum 13 is | continues to rotate, the projection 63 passes the right pole piece 61 of the transducer 57 again. However, there is no information from the data source 77 to the AND gate 79, which corresponds to the activation of a new print line, and since the Switch 95 is not closed, this signal has no further effect. As the timing disk 19 continues to rotate, arrives the second row of characters through the print area, and at the same time a second row of teeth U9 on the pole piece 59 of the transducer

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57 passed ο The corresponding signals pass again the phase demodulator to the comparator, and if they match of the signals in the comparator 75, a second character is printed

It is thus seen that the pressure pulses are not passed in the rest position of the hammer carrier and only one generated by the projection 63 on the transport timing disk 21 pulse can put the assembly in transition ο Once the carrier, however, is · ³ · ne movement has begun ", the the Coupling process control pulses blocked by the open switch 95 so that only pressure pulses are effective. At the end of a print line corresponding to the timer setting for a certain line, the timer 97 switches off the silicon rectifier 81 and de-energizes the solenoid 45, so that the hammer carrier 25 disengages from the drive belt 17. The spring 47 returns the hammer carrier to its rest position so that it is ready for a new line of printing.

The control device according to the invention can still move in such a way changed "Z.B", since there are two rows of Printing types are arranged on the drum 13 and two rows of teeth 49 on the timing disk 19 are per revolution of the drum ~ mel 2 characters printed. Since the pressure pulse only once per If the pressure cell is used, the speed of the Transport ™ can be adjusted Reduce the timing disc 21 without losing synchronization The use of a reduction tapered gearbox in proportion 2; 1 to reduce the speed of the transport clock disk 21 half is therefore possible »

If the comparator 75 is not reset internally after each printing of a pen, the output signal can be set to dor device 83 can be used for this purpose, since the number of teeth 49 corresponds to the number of characters which are in a given print position can be printed »For this purpose, a

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be of two ways required can, for example, two projections 83 constitute transport timing pulley 21 mounted at an angular distance of 180 °, it would then be a projection 63 on the pole piece SSL -each row of teeth HS ,, Using pass by scanning a journal 63 would be an upper setting in a ratio of 1: 2 is required for the bevel gears 51, 55 in order to increase the speed au. The transport clock disk 21 would then rotate twice as fast as the clock disk 19.

The pulses triggered by the projection 6 3 can also be used as an input signal for the data source 77 in order to display the print positions along a print line 27. The projection 83 may of course also be replaced by a slot J and the winding direction of the winding 67 seinο then reversed on the pole piece 61 In this case, again a counter "in polarity de would result: c <waveform of Transporfctaktscheibe 21st

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SAD

Claims (1)

if P a t e η t a η s ρ r ti c h e Control device for a serial tendon printer with a the printing types having rotatable printing drum, one on stop hammer mounted on a hammer carrier, the hammer carrier has a rest position, and with a device for continuously transporting the hammer carrier along a Print line parallel to the axis of the drum, g e k © η η « characterized by a synchronous drive with the drum sum of the same coupled clock device (19,21), by a two key ends (59,61) having transducer (57,59,65,67) for Removal of clock markings of the clock device (19,21), controlled by one of the signals of the first key end Coupling device (15) for coupling the hammer carrier (2.5) to a transport device (17.39, Hl) for the same, and by a triggering device (33) controlled by the second key end to the. Actuate the hammer in the correct Angular position of the drum in relation to the print line. 2. Control device according to claim I ₈ gekennzeiah «net by a locking device (95) which only releases the control signals for the coupling device (15) when the hammer carrier (2 5) is in its rest position» 3, control device according to claim 1 or 2, characterized in that a blocking device is provided which blocks the control signals for the triggering device »when the hammer carrier (25) is in its rest position ·, 1. Control device according to claim 3, characterized in that the converter (57) has two sensing points (pole » pieces 59,61) made of magnetically conductive material, the are surrounded by series-connected windings (67) « 109828/1718 5. Control device according to claim 1 to 4, characterized g e leenn draws that the clock device has a clock disc (19) with magnetic flux-conducting teeth (49), the Angular position that corresponds to the printing types on the drum (13), as well as a transport disk (21) with at least a magnetic flux-conducting projection (63). 6. Control device according to claim 5, characterized in that g e k e η η « shows that the teeth (49) of the timing disc (19) run past in the immediate vicinity of one key end (59) and the projections (63) of the transport clock disk (21) in the immediate vicinity Proximity of the other probe end (61) of the transducer (57), the arrangement being such that the passage of a tooth (49) generates a different signal at the associated key end (59) than the passage of a projection (63) past the associated one Groping end (61). 7. Control device according to claim 5 or 6, characterized in that “-characterizes that the timing disk (19) has at least one tooth-free area and that the projection (63) is arranged on the transport clock disk (21) so that he passes the assigned clock point when the tooth-free area passes the assigned clock point (59). 8a Control device according to Claims 1 to 7 _S, characterized by a separating device for separating the | different signals generated by the teeth (49) on the one hand and the projection (63) on the other hand and for forwarding the separate signals to the clutch actuation device (45) or the hammer actuation device (33). 9. Control device according to claim 6 to 8, characterized in that ,, ge «» indicates that the transducer (57) is designed is that the signals generated by the teeth (49) and the projection (63) have opposite polarity. 109828/1718 OK control device according to claim 9, characterized in that g α k e η η ~ shows that the separator has a phase demodule ** lator (73) forms, 11 ο control device according to claim 5 to 10, characterized in that « indicates that the timing disks (19, 21) are driven synchronously and that the projections (63) are not simultaneously tig with the teeth (U9) past the assigned probe ends « to run·