DE2221871A1 - WRITING - Google Patents

Description

KARL-HEINZ SCHAÜMBÜHÖ ^

PATENT REQUEST

Nixdorf Computer AG

MAUEHKIBCHEBSTH. C0811) 0810

Paderborn '4 MA11972

Pontanusstrasse 55

3N5 1572 D

. X. Writing

The invention relates to a writing unit for successively line-by-line application of characters on an over A recording medium guided by a platen roller, arranged next to one another on an arcuate pivot axis and type levers acting by pivoting movement on a common recording point.

. The best-known example of a writing mechanism of this type is realized in the usual typewriters, in which the type lever arrangement lies on an arc of a circle, which is oriented relative to the platen so that the type lever hit the side of the platen and on their supported ends can be operated mechanically or electrically. Complex mechanisms are required for this, which must be arranged below the writing unit in order to activate the type lever with as little effort as possible, but with high accuracy and the highest possible

309846/0697

ORiGlNAL INSPECTED

To be able to pan speed. In writing works of this type, the writing speed is determined by the shape and the mass of the movable elements, in particular the type lever, is determined. The mass of type levers, however, is again by a predetermined minimum size and to a significant extent also by those attached to the type levers Types determined. In any case, the types lie in their rest position on such a line that they are at similarly mounted type levers have a single common point of impact on the platen, so for all type levers or types of similar writing processes are generated.

The advancing development in the field of data processing machines requires writing mechanisms with extremely high writing speed, but also with optimal Writing accuracy and operational reliability. Conventional writing mechanisms with type levers allow a writing speed from 20 to 24 strokes per second. Other writing works that work with so-called ball heads, enable a writing speed of 20 keystrokes per second. Should the writing speed be above such Values are also increased, so it is necessary for writing mechanisms with type levers to reduce the mass of the movable To reduce elements, in particular the type lever, for which purpose the type lever can be shortened. This is how it is possible, a writing speed of approx. 30 to 35 characters to achieve per second. However, it is in the interest of a flawless roechani-see working method of this kind Writing mechanisms required to execute the type lever with a certain predetermined minimum stability so during the writing process and during their movement, they are particularly affected by the action of their drive elements Do not bend. Bsi the one used so far

303846/0637

Type levers with a bent type head can also cause rolling movements occur because their center of gravity extends outside of their through the bearing point and the lever length Oscillation plane lies. For this reason, too, minimum requirements must be placed on the mass of the type levers, which are not undershot may be.

The well-known writing mechanisms with type levers have something for everyone Complicated drive mechanisms to be provided for individual type levers. When moving forward must Each type lever drive initially overcome a retraction force that re-engages the type lever after the writing process returns to its rest position. Each type lever should be accelerated as positively as possible when it hits the stop. There but the drive impulse for the type lever in the known writing mechanisms already after half a forward movement stops and then only its kinetic energy can be used up to the stop, is through-the As the return spring becomes more and more tense, a large part of this energy is consumed. In addition, they are difficult to use Lever ratios are required for each type lever in order to achieve a perfect one with the least possible effort To enable the writing process within the shortest possible time. However, all drive mechanisms cause a space requirement that leads to such a large overall writing unit that the arrangement of the type lever on the segment an arc of a circle in front of the platen is absolutely necessary. It is also known the type lever to be arranged on a full circle, which lies in front of or under the platen, but this creates writing works, which are disproportionately large and whose drive mechanisms may completely block the view of the writing mechanism. In addition, this results in cooperation

309846/0697

ij. »» _T

with a keyboard arrangements which by no means allow a compact display of a writing unit. With the formation of a typehetoelant? Iebes it should be noted that a mechanical drive in connection with a keyboard is only ever oriented in one direction, while the drive is. to the type lever, due to its radial arrangement, each type lever must be in a different direction. »In general, the drive and transmission taxag me for the middle type lever. For all aaderea type levers, the change in angle corresponds to the size of the angle that the respective off-center type lever encloses with the middle lever. The ultimate guy love! fc.ab@n the largest deviation. If the ffaimgE-wisiksl of the typan segment grows over approx. 150 ° and if it approaches 360 °, as © the full circle, a clear mechanical drive is practical when building "the" he-atlgen Sohre-lbsiascMnen ©

Other requirements for a writing work also relate to the requirements of the support carrier on the platen. It must be possible to guide the new recording medium unhindered onto the platen, remove it from it and simultaneously observe the writing process not only normal particularly in the · data processing paper sheet sr into consideration, but also, for example, debit cards or other rigid recording medium? tolerate no very strong curvature. in the implementation of SsJosiellschreibwerken are therefore compromises of various kinds zn close that primarily Scbreibgeschwindigkeit by certain mechanical

309846 / 0S97

Have severely restricted the minimum sizes of the individual parts «,

The object of the invention is ₉ to enable the arrangement of a short type lever to a full circle immediately before the platen roller and thus reduce the size of the di © types lever. For this purpose, a drive is to be used that does not require a complex mechanism of many moving elements between the ³ Tvpenaeb © platen »

A writing mechanism of the aforementioned Ir-t is designed according to the invention for this task in such a way that generation of the pivoting movement in each case of the selected type lever is provided by a hydraulic and / or pneumatic drive common to all type levers, which via a hydraulic and / © d © r pnemaatiseli ® ;, all! Type levers assigned control in © iae Wirkverbisduag ®it a® one of the number of T ^ osa & ebeX eatspreefeesid © a Äasaäi is drive elements koppaloai " ⁵ Igt, rad el ^ i Wilalvor ^ ieiattag © are provided, welel ^ ® sntspreöhend ä ©! ⁵ Selection of each type lever Ib a given position can be moved and in this position ■ the coupling of the drive with the drive element of the selected lever by influencing the control over the range of this aluminum drive element

Decisive for the realization of a solar grating The invention is based on the knowledge that when the mass of the type lever is reduced to generate a friction process a pivoting movement of the type lever can take place with a lower force than was previously the case with larger ones Type levers was necessary, but without reducing the speed of the type lever moved. It is now possible a hydraulic and / or pneumatic drive

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to be built so small that force effects can be generated with values that are completely sufficient for sufficiently rapid movement of a type lever with reduced mass. Hydraulic and / or pneumatic systems generate such force effects at such a speed that the kinetic energy of the type lever required for a proper writing process is available. In addition, hydraulic and / or pneumatic drives can be set up at a point away from the writing unit, since they can only be connected to the writing unit itself by means of Di ⁴ UGk or suction lines and are assigned to all type levers together. The writing itself only requires hydraulically or pneumatically operating control elements, which are arranged in control channels, 10 that a pressure or negative pressure acting on them enables their movement fast and precisely controlled visual friction movement of the Tjj ^ en levers possible. In addition, it is irrelevant in which position the type levers are arranged in relation to the control and drive elements, because there are no lever ratios and joints whose mass has to be moved and which must have a predetermined position. There is also no need to overcome any restoring forces that are generated in previously known writing mechanisms, for example with relatively strong springs. Another decisive advantage is that the drive force for the type lever between a keyboard and the respective type lever does not change direction, since such a connection is only available with regard to the control, but not for the direct drive.

A writing unit according to the invention can advantageously be of this type be further developed that the drive is a pulse drive, the pressure or vacuum pulses with one of the Rubbing speed or a complete drag The frequency corresponding to the writing speed is generated.

Such a design of the drive makes it possible to implement a particularly simple control for the respective type lever.For this purpose, only, for example, a valve actuation is required within the hydraulic and / or pneumatic drive, through which the pressure or vacuum impulses are directly selective transferred to the hydraulic and / or pneumatic control = · rank. If these pulses have a frequency which corresponds to the specified writing speed or to an integer multiple of this very speed, the exact point in time of the respective valve opening is irrelevant; can get. Of course this is "particularly reliable the case _s when the frequency of printing" or negative pressure pulses is an integral multiple of the writing speed.

The pressure or negative pressure pulses can be generated with simple pump devices, each of which © ine can be assigned to all type levers or a group of type levers. Such pumping devices can either be provided individually and generate the pressure pulses and the negative pressure pulses in a working chamber ^ it is however, also possible, for example two Pmap devices provide the phase shifted, preferably in push-pull work. The mechanical drive of such pumping devices is carried out in a simple manner by rotary drives, which with

309846/0697

Eccentric bearings are provided. In this way, any write speed can be created using Ds'efcgahlregitll ^ mag : any. With electric or automatic

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Brelrfcri®'ö © be alageatellt 3 _"9 di @ ia Sshreibgeschwindigkeiten to the order of 60 strokes per second führera" t4 ^f 3s is located in the first line thereto, that a hydraulic ^r aM / or pn © \ Mat.is © hsr drive practically inertial

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gör iaifeaxi cIüs iiydraulischen t3 siSglicfe, cioS an Ans with -Binem sit circumferential grooves ppelt, whereby etit connectionstelas2, ggi -: iit © n with the control lisefeea and / or pneumati- ^ -jx-ssfitis are provided.

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fsaaimcesi Itoinngsnuten ver ilt ijii: d, Äöß 3 ± © in regeldöv ^ au ^ iilnm ^ dss Drehelesää ^ g Ycrbölgefül ^ t be, g d-si; k & 2istar.teii pressure in one iarpulsav; ige ühterbre- -ää the Sswif.iy, ;;; and the

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Pump arrangement is. The Dpuckinspulse can dem Writing mechanism or the Äntrietoselesaenten for the type lever can be fed in from two different directions, see © that they have an effect similar to that of negative pressure impulses compared to the pressure impulses of the opposite pressure impulses Have direction,

The generation of pressure pulses is f ®τη @ τ means © linearly movable elements, eg _e valve genius "b @ r, or also elek ™ tromagnetic valve ©, which can be controlled with a given frequency.,

It should be pointed out that the drive for the type levers can be hydraulic or pnetsmatisoh, edoeli auoh according to the principles. Bite is easy eingusehea ₉ for the effect elxj.es pneumatic drive ^ ^ is the Anigen a hydraulic drive iQiii \ ral @ _at? where üu take into account "is that b © i feydrauliaehea üntriebsmsditaa the incompressibility eier liyi ^ aislilsluigksit v © s ¥ © part for the writing ability a © isi k & xm <. However, there are also problems with sealing _g furthermore, the handling of hydraulic fluids compared to a pneumatic system is possibly associated with further disadvantages. There is also the advantage of a pneumatic M drive medium that the specific weight of air is practically negligible compared to the drive fluid. Thus, the force values at the beginning of a Impulg.es in a drive medium are much lower than in a hydraulic drive medium's ₉ because the successful mass at a given acceleration requires a correspondingly reduced force. The statements in this description "however, apply in total to such arrangements - which can work hydraulically and / or pneumatically, go that see

3GS84S / CsSi?

a special note on "both possible ways of working not necessary in the following.

In the embodiments described above, the invention can advantageously be further developed in such a way that the control has at least one pressure chamber which is concentric with the arcuate pivot axis of the type lever and is permanently connected to the drive, the volume of which is limited by each number of selection slides corresponding to the number of type levers available which are movable by means of the selectors released in each case into a position in which si ^ a barrier between the pressure chamber and the respective drive element to release.

This development of the invention enables a particularly compact construction of a writing unit. If the type lever are arranged on a circle or, for example, on two semicircular segments », a special Drive segment; be assigned »which» with channels is provided for guiding the print medium and in these Contains channels drive elements for the type lever. Wemi the type levers themselves are arranged on a circular arc-shaped pivot axis, so those channels run that the pressure pulses of the drive to the type levers or their Feed drive elements ^, advantageously in the radial direction starting from the pressure chamber. In that a pressure chamber that is concentric with the pivot axis is continuous is provided, the pulsating can be used in a particularly simple manner Print! »Effect of the drive device of this Pressure chamber can be fed to any point of an entire writing fragment with several type levers. From the arc-shaped pressure chamber you can

4 Branch off the side edge ^ dl © to ^ e ?? © Ila a drive element for - each can lead a type lever ». Such a drive element can be "for example a piston guided in a work space""which swivels the type lever assigned to it Sequence of movement of the type lever in the forward direction guaranteed Since an Ansabl selection-Eohiober corresponding to the number of existing type levers is provided, each of which sits with a part in a vent-like hole, which in certain positions of the selection slide with the working space of the drive elements for the type lever m verbindan _a iat the only control operation therein ₉ "WiJaI that the devices don, ÄusviahlscMebes ⁴ DE® each release _s he UbB at d®a means. Eintreter, ausgewMhlten type lever of an Druckimpuls®s in the BruaMia ^ Mesr ¹ in order acting overpressure be weighed kars _P to the Siaaal from the kre isbow-shaped pressure chamber sua Arb ^ itsraua for the drive element of the selected Typeahebsls dureh ¥ @ r "bimden is.

In a further development of the concept of the invention kSaaen also as two concentric pressure kaiisaerfö verge se ± n _P of deaea one is permanently connected with a second Aatfiebsalementea for the type lever and in case of excess pressure causes a movement of the type lever possibly in its position ₀

So that it is possible besides the? Forward movement to generate the backward movement of the type lever by means of a pressure pulse ©. A type lever, for example a two-armed bolt, can be provided with a direct drive in _f

3098AS / 0S97

one lever arm of which the first pressure chamber acts, while the second lever arm is acted upon by the second pressure chamber will. This means that no suction effects are required to return the respective type lever to its rest position. and a more uniform operation of a writing unit can be achieved.

In the case of impulse pressure generation, pressure equalization is required between the working spaces of the drive elements and the outside space in the time between the individual pressure impulses. For this purpose, an isonsentric pressure chamber can advantageously be connected to the outside space via the drive. This connection can, for example, be realized with control slides coupled to the drive shaft, which in the given positions of the drive shaft open a connection to the concentric pressure chamber with (Mm iinßenr-aiajs * This is particularly advantageous; / iam two connections are provided that work in reverse! ·· ^, The common drive element for this PuMp ^ os-Pielrtimgesi t ^ -sibt then the two control slides, 30 d: & Q dies © inevitably work with a push-pull operation open speed and eg in their eiasn Ssrfcrsmstellimg a pumping device with the Aui ^ in'mim a binding * "_ι _# over-3teilung extreme 413 aMare Puiapvorrlolitimg with the exterior comparable in the other -, -is CISR üntriea dm * ch ain Drelielement with ^Umvst; more light , ^ o kagm the connection of the pressure chamber with U-3M outer ring also run over the rotating element, which is expediently designed as a sleeve which is mounted on a cylindrical pin dr Ehbar is arranged and in the one connection sl & er Uafangsnut with the space between the sleeve and the pin is provided. If this space is in connection with the outside space, which is easy to achieve structurally, it is then in a simple manner

309346/0697

a connection between the pressure chambers and the outside space is also created in predetermined positions of the drive.

The two variants of returning the type lever to the rest position either by suction or pressure, lead to two different working principles. When using only one pump device that works with pressure and negative pressure, when the type lever is in the writing position, the overpressure created in the pressure chamber is compensated to the outside by the respective drive element then exposing an outwardly leading bore. Subsequently, negative pressure occurs in the working space of the drive element. Even at low Rücicgang of type lever, the lead-out hole is closed again conveniently by the drive member, and the negative pressure affects via the drive element to the type lever * When the negative pressure eix ^ en certain value he-re ISFET has ₉ overcoming the holding force , with which the selection slide is held in its selected positionL If at this point in time the type lever has not yet reached its rest position and the drive element is still compressing, the compression pressure can escape to the outside Outside space can be provided. In the corresponding working position of the drive, which is then reached, the negative pressure can be equalized to the outside through the connection running through it. In this case, a single chamber acts alternately as a pressure and a vacuum chamber.

When using two pump devices that work in push-pull or a pulse-controlled constant pressure source is the pressure chamber via the drive in its un-

3Q984B / 0697

negative pressure position connected to the outside space. The negative pressure position of the drive is that position in which the respectively actuated drive element for a type lever is returned to its rest position. Regardless of whether this is done by pressure or negative pressure, the normal pressure conditions must be restored before the next working stroke, so that the working volume of the pneumatic and / or hydraulic drive can be used properly. If the rotary element for the drive in the lower thickened position releases a channel that creates the equalization connection, a simple way of equalizing pressure between the pressure chambers and the outside area is thus created.

The invention is illustrated below with reference to the figures Embodiments described. Show it;

Fig. 1 shows a writing mechanism according to the invention with a pneumatic one Drive in the form of an .Iq single-cycle operation working diaphragm pump,

FIG. 2 shows views of the writing work shown in FIG. 1 according to the directions II, III and IY shown there in a combined representation,

Fig. 3 bsw the pressure distribution. the amplitude of movement in the pneumatic drive shown in Fig. 1 during a given operating section,

FIG. 4 shows the pressure distribution in the work shown in FIG volume of the writing unit during the specified operating period,

Fig. 5 shows a further embodiment of a writing mechanism according to the invention with a pneumatic drive in the form of two diaphragm pumps working in push-pull operation,

30S8 h 6/0697

6 shows a further embodiment of a writing unit according to the invention with a pneumatic drive to which a constant pressure is supplied and the one Push-pull pressure effect generated,

7 shows a representation of the pneumatic drive shown in FIG. 6 in the view YII-YII,

FIG. 8 shows a representation of a control element in the pneumatic drive _{9 shown in FIG. 7}

FIGS. 9 to 12 are sectional views IX ₅ X, Xl and XII of the control shown in Fig. 8 _s

FIG. 13 shows a working diagram of a writing unit of the type shown in FIG. shown type and

14 shows an overall view of a writing device consisting of writing units aaeJa. exercises exhilaration.

The writing units shown in the figures each show a type lever and its drive elements in a side view. The elements common to all type levers, which are designed according to the arrangement of all type levers partially in the shape of an arc of a circle ₉ therefore have a sectional view.

1 and 2, the arrangement of a type lever 10 with an associated pneumatic drive is wad more pneumatic Controller in its arrangement aa of an orphan 24 is shown. This representation is a Section through a type lever group arranged on an arc, which is placed in such a way that the pneumatic drive and the type of control common to all type levers is visible. In addition, the type lever 10 can be seen with the movable drive elements assigned to it.

309846/08 9.7

Such items that are not necessary to understand the invention, such as screw connections, bearings and couplings that are generally known to those skilled in the art in connection with the construction of writing works, are not shown in the figures.

The type lever 10, which carries a type 12 at its outer free end and at this end in the rest position an arc-shaped magnetic strip 50 common to all type levers is held on an arc-shaped one and in Fig, 1 mounted bearing axis 16 shown in section, so that it is his when pivoting Type 12 leads over a circle 20 against the platen 24. The arcuate bearing axis 16 is in a type lever segment 48 out, which has a guide slot for each type lever. So the type lever 10 is within of the slot 18 pivotable. The type lever 10 is at its end mounted on the bearing axis 16 with teeth 14, which engages in corresponding teeth 28 of an intermediate lever 26. This intermediate lever 26 is on another, concentric to the first and in the shape of a circular arc Bearing axis 30 rotatably mounted and provided on its second arm with further teeth 32, which are shown in a toothing 34 of a drive lever 36 engages. This can be pivoted on an arcuate bearing axis 38 stored. The pivoting movement generated by a pneumatically driven piston 46 in a manner still to be described of the drive lever 36 enables a slot 42, which is provided for each drive lever in a drive segment 54 is, which is therefore shown in Fig. 1 in a partial section. There is a bump stop on the drive segment 54 22 made of an elastic or hard resilient material, the upper end of which in a known way a Frell-

3098 4 6/0697

Appearance of the type lever 10 directly on the platen 24 prevents and a trouble-free return movement of the type lever 10 after hitting the platen 24 guaranteed.

Radially outside the type lever segment 48 and in front of the drive segment 54 an arrangement 70 of circular arc-shaped selector rails is provided, with which in FIG Way the pneumatic control for one of the existing ones Type lever 10 is actuated. The selector rails can work analogously to an arrangement, as they do for example is known for teleprinter. They surround the overall arrangement like a ring, so that they have an effect on the control for ^ every type lever is possible. Through cutouts in the selector rails according to a predetermined coding can be achieved that to control a selected type lever one and only one position combination of the selector rails must be set to each other, with which this type lever can be influenced in a manner yet to be described.

Below or outside the type lever segment 48 and the Drive segment 54, the pneumatic drive is provided, which is attached to a bearing frame 86. The storage frame 86 is on bearing rods 90 and 94 by means of guides. 92 and 96 mounted so that they can be moved if necessary. In the main the drive consists of a diaphragm pump with a pneumatic chamber 98 in which a diaphragm 100 is provided is, which is set in vibratory motion from its underside via an eccentric rotary drive and the air in the pneumatic chamber 98 compressed rhythmically, so that a pulse-like pneumatic driving force for the Type lever is generated.

3Ö9846 / 0SS7

In the following, the mode of operation of the arrangement shown in FIGS. 1 and 2 is explained in conjunction with an explanation of the other individual parts described. For this purpose, the generation of the pulsating driving force is assumed and their influence on the control and the drive of the type lever 10 depending on the setting of the selector rail arrangement 72 explained.

The pneumatic chamber 98 is formed on the one hand by the bearing frame 86 and on the other hand by a frame 102 and an oscillating plate 104 held by it. The liembran 100 is provided between the bearing frame 86 and the frame 102. This can consist of two air-impermeable material layers ", on the upper side of which a counter plate 101 is provided, which encloses the membrane 100 between itself and the lower oscillating plate 104 The vibrating plate 104 is connected to a cylindrical guide sleeve 116 via a flexible and airtight connection 114 which forms a channel 123. This is fastened to an eccentric bushing 118 which serves for the eccentric guidance of a drive shaft 120 with a square profile 104 is directly coupled to the guide sleeve 116 via rockers 108, only one of which is shown in FIG Diaphragm bore 121, the channel 123, a channel 124 in the guide sleeve 116 and a bore 122 in the eccentric bush 118 is connected to the outside space. The rockers 108 are attached to a pin 110

112 movably coupled to the oscillating plate 104. If the Bush 118 is rotated by the drive shaft 120, so there is an oscillation-like movement of the membrane 100 as a result of the rhythmic raising and lowering of the membrane Coupling. The flexible line 114 or the channel 123 can be used in the operating position shown in FIG. 1 the pressure in the pneumatic system is equalized with the outside space.

The pneumatic chamber 98 is via a pressure line 80 connected to your type lever segment 48. The pressure line 80 is at both ends by screw connections 82 and connecting elements 84 in the type lever segment 48 and in Bearing frame 86 attached. The bearing frame 86 is with a Channel 88 provided which connects the connecting line 80 with the interior of the pneumatic chamber 98, so that Each time the diaphragm 100 moves upward, a pressure increase is generated in a bore 60 of the type lever segment 48 will. This bore 60 is provided jointly for all type levers, but it can also be used in a group be assigned by type levers, so that each type lever on the shortest possible path with the pneumatic drive connected is.

If a pulse-like pressure increase is generated in the bore 60, this also occurs via a transverse bore 52 in a pressure chamber 58, which through an arc of a circle the entire type lever segment 48 runs and is assigned to all typeshebe3.n. In this pressure chamber 58 is therefore an oscillating or pulsed pneumatic pressure is available, the frequency of which depends on the speed of the drive shaft 120 corresponding to a predetermined writing speed or "an integer multiple of the writing speed can be adjusted.

3Q9846 / 0G97

A control is assigned to each type lever, which consists of is formed in the drive segment 54 provided channels which, each by one in a radial bore 62 guided selection slide 69 are opened or closed and thereby actuate the piston 46 already described, which pivots the drive lever 36.

The control process for actuating the type lever 10 shown in Fig. 1 is initiated in that the circular arc-shaped selection rails of the arrangement 72 are brought into a position relative to one another in which a flattened area at the lower end of the selection slide 69 falls into a gap formed by the recesses in the selection rails can. For the setting movement, the selector rails can be shifted relative to one another around the entire circular arc-shaped arrangement of all type levers by an amount specified by their coding. For this purpose, they are on the drive segment 54 by means of a support surface 78bzw. a support element 76 and a plurality of guide pins 74 attached. If the selector rails are in such a position that the flat 70 shown can fall into a gap formed with its recesses, the selection slide 69 shown is due to the increasing pressure in the pressure chamber 58 down into the area of an internal magnetic strip 79 moves, so that he releases eisis Abmifelgbohrwig 64 and this comes with the Druckisa Μϋ & ΐ- 58 1 »;« connection. The pulsating pneumatic pressure in the pressure chamber 58 can then act on the piston 46 guided in the enlarged bore 44 and moves it to the right from the rest position shown in FIG can act and the drive lever 36 wa the circular arc

309846/0687

Bearing axis 38 pivoted around clockwise. Through this the teeth 34 and 32 rotate the Intermediate lever 26 on the circular arc-shaped bearing axis 30, so that via the coupling of the teeth 28 and 14 of the type lever 10 is pivoted about its arcuate bearing axis 16 in this way; that he can get the Type 12 via route 20 to the Platen 24 leads. Through the pulse-like control of the pneumatic pressure in the arc-shaped pressure chamber 58 and the initially acting holding force of the magnetic strip 50 causes a sudden movement of the Type lever 10, so that the energy required for the writing process on the platen 24 is available. As already described, a bumper stop 22 is provided, which the type lever 10 in the last part of its movement catches hard, prevents a bouncing phenomenon directly on the platen 24 and the return of the type lever 10 introduces.

The control of the last part of the movement of the type lever 10 takes place in the manner described up to one Point at which the piston 46 releases an opening 65 during its forward movement, so that the in the pneumatic System can compensate for existing overpressure through this opening 65 to the outside. As a direct There is no driving force acting on the piston 46, but on the other hand a certain kinetic energy of the type lever 10 is present, the type lever 10 flies in the direction of the platen 24 and hits the bumper 22. This is set so that the type lever is caught hard, after which the type 12 hits the platen 24 strikes and immediately thereafter a return movement of the type lever 10 begins due to the spring action of the bump stop 22. Since the intermediate lever 26, the drive

309846/0697

lever 36 and the piston 46 form-fit with the type lever 10 are coupled, these elements follow the movements of the type lever 10, and the piston 46 is due to the return movement of the type lever 10 also moved back. The return movement of the piston 46 is supported by the pneumatic drive, which now generates suction. The membrane 100 has meanwhile been continued to rotate the drive shaft 120 is moved downwards, so that the volume of the pneumatic chamber 98 is now increased again and a negative pressure in that formed from the bore 60, the transverse bore 52 and the circular arc-shaped pressure chamber 58 Space is created. This supports the return movement of the piston 46. The selection slide 69 is still through the magnetic strip 79 is held in its lower position possible through the gap in the selector rail arrangement 72. the Holding force of the magnetic strip 79 is dimensioned so that the return of the selection slide 69 only at a predetermined Negative pressure in the circular arc-shaped chamber 58 can take place suddenly. At this point the type lever can 10, however, are already close to its rest position shown in FIG. 1, in which it is by its circular arc-shaped Magnet bar 50 is attracted. During these processes, the piston 46 is moved to the left again, where he the air present in its bore 44 or in the branch bore 64 corresponding to its return movement through a channel 66 can convey to the outside if the selection slide 69 has been returned in the meantime. This is through the thinner shaft 68 of the selection slide 69 possible. The arrangement thus has its rest position shown in FIG. 1 again achieved, in which a pressure equalization between the pressure chamber 58 and the outer space via the membrane bore 121, the flexible channel 123 and the opposing bores 124 and 122 of the rotary drive can take place.

309846/0697

- 23 - ^ ■

In FIg. 2 shows an arrangement with several type levers 10 in different sections II-II and IH-III and in view IV, as indicated in FIG. 1. Furthermore, the pneumatic drive on the underside of the type lever arrangement is shown in a side view. The right-hand section II-II shows the type of supply of the pulsating pressure into the arcuate pressure chamber 58 via the connecting line 80 _9, the bore 60 and the transverse bore 32. The parts of the pneumatic drive on the underside of the arrangement shown illustrate in the side view shown in FIG. 2 the assignment of the pneumatic drive as a single unit to all existing type levers 10 '

The type lever segment 48 is shown partially cut through the section H-II; the slots 18 for guiding the type lever 10 can be seen at its upper, non-cut end. From the section IH-III, which compared to the section H-II according to the representation in FIG. Slightly shifted to the right, in FIG. But is shown next to the 2-section H-II _s is the arrangement of the selection slide valve 69 in their bores 62 produced in the drive segment 54th Furthermore, the flattened areas 70 of the selection slides 69 can be seen, which, depending on the setting length of the circular-arc-shaped selection rail arrangement 72, can fall into a gap formed by a specific juxtaposition of their cutouts 73. The coded distribution and dimensioning of the recesses 73 on the inner circumference of a selector rail can also be seen. The selector rails can be adjusted to one another by slight displacement in the circumferential direction in such a way that the flattened area 70 of only a single predetermined selector slide 69 can snap into the mentioned gap. By arrows is

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the movement of the selection slide 69 in the radial direction indicated.

It can also be seen how the drive segment 54 lies relative to the type lever segment 48 and that between the two Segments 54 and 48 the circular arc-shaped pressure chamber 58 runs, in which a pulsating pneumatic Pressure is available, which is generated by the pneumatic drive shown in the lower part of the figure and the pressure chamber 58 via the connecting line 80, the bore 60 and the transverse bore 52 in the type lever segment 48 will.

The side view IV finally shows several type levers 10 with types 12 fastened thereon, so that the assignment therefrom the entire writing arrangement for platen 24 can be seen.

In Fig. 3 the course of the pneumatic pressure ρ or the amplitude a of the diaphragm movement in the pneumatic chamber 98 of the diaphragm pump is shown for a writing unit of the type shown in Fig. 1 and 2 as a function of the angular position of the drive shaft 120 with respect to a zero position , whereby the pressure equalization occurring in a certain position is not taken into account. As a result of the rotation of the drive shaft 120, the membrane 100 is moved upwards and downwards, with these two movements, due to their different directions, generating an overpressure or a negative pressure compared to the external pressure, the frequency of which depends on the speed of the drive shaft 120. The illustration according to FIG. 3 shows, for example, as an initial state corresponding to the position shown in FIG. 1, a negative pressure with the value -P,

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by rotating the drive shaft 120 to. the amount IC changes into a pressure + P, the middle position of the diaphragm 100 being passed through for the pressure value zero. This representation is about relative values which, with the amounts -P and + P, indicate an underpressure or overpressure compared to normal pressure. Without taking pressure equalization or mechanical side effects into account, a pressure distribution that is practically sinusoidal over time would be generated in the pneumatic chamber 98, so that the illustration in FIG.

Fig. 4 now shows the actual pressure profile in the pneumatic chamber 98 and in the circular arc Pressure chamber 58 and, assuming an actuated selection slide 69, also the one over time changing force acting on the piston 46, which ultimately moves the type lever 10. With this representation is assumed that as a result of certain mechanical tolerances and by a control movement of the Selection slide 69 required time and the associated increase in volume of the pressure chamber 58 the pressure increase before the piston 46 begins at a point in time, that of the Time zero or the angular position zero of the drive shaft 120 is different. After that in this position if the pressure is equalized with the external pressure, the increases Pressure according to a characteristic corresponding to the structural design of the control elements up to one Peak value + Pk, the piston 46 is already moved in its bore so that the type lever 10 in the direction is pivoted on the platen 24. During this The process takes place nevertheless in consideration of the size of the Volume of the pneumatic chamber 98, a constant pressure increase in front of the piston 46, because that released by it

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Volume is significantly smaller than that of the pneumatic chamber 98. The pressure value + Pk is also higher than that in Fig. 3 shown pressure value + P, because in the actual function in the starting position shown in Fig. 1 Pressure equalization takes place and the compression process begins with the value of the external pressure as the output pressure.

The overall arrangement is now dimensioned in such a way that the non-positive drive of the type lever when the pressure value + Pk is reached 10 has ended. At this point in time, the opening 65 is made by the piston 46 in the manner already described released so that there is a pressure drop in the pneumatic system which is comparatively steep.

As already described, the last part of the movement of the type lever 10 takes place through the kinetic given to it Energy. After the Type 12 hits the platen 24, the bump stop 22 initiates the return movement of the type lever 10, and through the positive connection of the type lever 10 with the piston 46 via the intermediate lever 26 and the drive lever 36 becomes the piston 46 moves in the reverse direction and closes the opening 65. By continuing to rotate the drive shaft 120, the membrane 100 is now moved downwards again, so that in the control system or in the arcuate pressure chamber 58 a negative pressure already arises, as shown in FIG. 4 by the negative profile of the pressure distribution curve is. The course up to the negative peak value -Pk does not necessarily have to be symmetrical to the positive one described Be formed pressure curve. At a predetermined pressure value between the zero or external pressure value and the Value -Pk is sucked in the selection slide 69 in the manner already described and overcomes its holding force

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Magnetic strip 79, so that the shaft 68 of the selection slide 69 with a reduced diameter is connected again creates between the bore 64 and the channel 66, whereby the air then still moved by the piston 46 after can leak outside.

The further distribution up to the negative pressure value -Pk can now come back independently of that in the rest position mechanical parts take place, with only the further rotation of the drive shaft 120 is decisive for the pressure curve is. When the drive shaft 120 returns to the position 2 TC shown in FIG. 1 within its sleeve 116 comes close, the pressure equalization between the pneumatic chamber 98 and the outside space via the membrane bore 121, the flexible connection 114 and the bores 122 and 124, so that the external pressure in the pneumatic control system is restored, as it is in Fig. 4 by the steeply rising branch of the negative part of the pressure distribution curve is indicated. From this point on, the processes already described are followed by the further Rotation of drive shaft 120 initiated again.

In Fig. 5 is another embodiment of a writing mechanism shown, which differs in principle from the one already described in that a two-part Drive is provided that works in push-pull. There are two pneumatic chambers 298 and 298a, which generate a pumping effect by means of a rotary drive common to them. The pressure conditions are also regulated in the two pneumatic chambers 298 and 298a by two control slides 326 and 326a, which are in bores 344 and 344a of a storage frame 286 are performed. The bearing frame 286 holds the illustrated between two side plates

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two-part pneumatic drive, with crossbars 290 and 294 as bearing elements between the side plates are provided and for the purpose of symmetrical drive, some moving parts are duplicated in a manner yet to be described are present, which are connected to one another by movable cross bars, which are shown hatched in FIG are.

Essentially, the writing mechanism shown in FIG. 5 operates with the pneumatic chamber 298 analogous to that already described, which also results from the similar training the pneumatic control emerges. The second existing pneumatic chamber 298a also has the task of return the type lever 210 to its rest position on a magnetic strip 250 after its actuation, so that the generation of a negative pressure is not necessary for this. The return of the type lever 210 is also done caused by a pressure effect. Both pneumatic chambers 298 and 298a operate in push-pull, i.e. their effects compete against each other by 180 ° or by Tf out of phase on. A differently dimensioned phase shift can also be implemented.

The pneumatic control sequence for the forward movement of the type lever mounted in a type lever segment 248 210 takes place in a manner similar to that already described with reference to FIG. 1. Depending on the setting of a selector rail arrangement 272, which is fastened to the drive segment 254 by means of intermediate layers 276 and 278, and to guide pins 274 is set, the flattening 270 can be one for each type lever 210 in a drive segment 254 The selection slider 269 engages in a gap in the selection rail arrangement 272 and then on a magnetic strip 279

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be held so that with simultaneous compression in of the pneumatic chamber 298, the pressure generated therewith via a channel 288, a connecting line 280 fastened by means of connecting and connecting elements 282 and 284 and a bore 260 and a transverse bore 252 in an arcuate pressure chamber 258 are available and as a result of the downward movement of the selection slide 269 in its bore 262 through a bore 264 to an in a bore 244 guided piston 246 can act.

In the case of a writing unit in which the type lever also moves back under positive pressure, the pressure chamber provided for the forward movement in the following as a call chamber one provided for the return movement Circular arc-shaped pressure chamber referred to as the recall chamber.

By the action of pressure on the piston 246 is a when The present exemplary embodiment is designed in two parts and is guided in a slot 242 of the drive segment 254 Drive lever 236 on its circular arc-shaped bearing axis 238 is pivoted on its upper lever arm 240 and can open one via a toothing 234 and a toothing 232 an axis 230 pivotable intermediate lever 226 and pivot the type lever 210, not shown further, via its teeth 214. At the same time the lower lever arm 241 of the drive lever 236 by pivoting the bearing axis 238 in the illustration according to FIG moved to the left so that it acts on a piston 247 and moves it to the left within its hole 245. While the compression in the call camera 258 is via the Selection and drive elements on the. Type lever 210 acts until a connection to the outside via a bore 265

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comes about is a simultaneous expansion in the recall chamber 259 by one with the spool 326a produced connection 342a to the outside without effect on the type lever 210. The recall chamber 259 should therefore not serve to support the call chamber 258 because a suction created in it not only the selected ones Type lever 210, but would affect all type lever, because the selection slider 269 are only the call chamber 258 assigned.

When the type lever is returned, the full compression pressure acts of the recall chamber 259 “which you have a Channel 288a, a connecting line 280a fastened by means of connecting and connecting elements 282a and 284a, and a Bore 260a is supplied to all pistons 247. Since, however, all pistons except one are in a fixed position of rest, only this one piston 247 can be conveyed in the rest position. The constriction 268 of the selection slide 269, together with the outwardly leading bore 266, has the one already described for the arrangement according to FIG Function of a pressure equalization when the piston 246 moves back.

The two pneumatic chambers 298 and 298a are controlled by a rotary drive common to them. They are each designed analogously to the chamber 98 already described (FIG. 1) and each contain a membrane 300 or 300a, movable oscillating plates 301 and 304 or 301a and 304a, each guided on a frame 302 or 302a, with a Approach 312 and 312a are provided, which is a vibration-like Movement is communicated. The rotary drive consists of essentially from a drive shaft 320, which is a square profile and thus within a sleeve 318

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is arranged eccentrically. This sleeve 318 is provided with four crank elements 306 and 307, which are at about 90 ° to each other are offset and of which only two can be seen in the section shown. The crank element 306 is each directly coupled to a rocker 332 at the pivot point 330, so that as a result of the rotation of the drive shaft 320 within the eccentric sleeve 318 an oscillating movement is transmitted to tabs 338, which are coupled to pivot points 336 and 310 and directly drive the extension 312 on the oscillating plate 304. The two rockers 332 are each mounted at a bearing point 334 in the bearing frame 286, a similar movement is communicated to the other oscillating plate 304a via connecting rails 340, which couple the rockers 332 with similar rockers 332a, which are each at the bearing point 334a are fastened in the bearing frame 286. These second rockers 332a are at articulation points via tabs 338a 336a and 310a are coupled to lugs 312a on the swing plate 304a of the pneumatic chamber 298a. These Drive coupling inevitably causes both pneumatic chambers 298 and 298a to work in push-pull.

For pressure equalization in the pneumatic chambers 298 and 298a, the control slide 326 and 326a are provided, which have a portion of reduced diameter. This Part can optionally depending on the position of the respective control slide 326 or 326a connect a channel 342 or a channel 342a to the outside space. The channel 342 or 342a leads to the pneumatic chamber 298 or .298a, so that this way the pressure equalization of the pneumatic chambers 298 and 298a and thus the call caramer 258 and the callback chamber 259 takes place. The drive of the control spool 326 and 326a is done by the action of noses 360 and

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36Oa on their outer ends. These lugs 360 and 360a belong to two connecting slides 354, which are horizontally with a slot 356 are guided on a pin 358. By the second crank elements 307 on the eccentric sleeve deflection levers 348 are moved, namely at a joint around a bearing point 350 on which the deflection levers 348 with the bearing frame 286 are connected. The reversing levers 348 are connected to one another via a transverse rod 352 which is also coupled to the control slides 326 and 326a via the connecting slides 354.

The rotating device shown in FIG. 5 is, as already mentioned, constructed symmetrically. The driveshaft 320 is provided with two crank elements 306 and 307 each at their two ends facing a side plate. Accordingly, they are also on each side of the pneumatic Drive two rockers 332 and 332a are provided. In the same way, a connecting slide 354 is a Deflection lever 348 and a connecting rod 340 are provided twice. The connection of these elements takes place in the sense a symmetrical drive by transverse rods 336, 336a and 352, which are shown in Fig. 5 in section.

The operation of the device shown in FIG. 5 can now be easily understood. The rotation of the drive shaft 320 causes a rhythmic generation of pressure pulses in the pneumatic chambers 298 and 298a. In described In this way, a lever arm 240 or 241 of the drive lever 236 is activated by the piston assigned to it 246 or 247 moved to the right. At the same time, the respective other lever arm with the piston assigned to it moved to the left. The control slides 326 and 326a are driven directly by the drive shaft 320

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such that a pressure equalization, as it is based on the in 1 has already been described, via the channels 342 and 342a. It is possibly too Note that the selected selection slide is initially activated with the expansion of the pneumatic Chamber 298 associated suction is to be brought back into its rest position with the channel 342 closed.

By dimensioning the spool 326 and 326a you can the process of striking the type lever 210 or his Type 212 can advantageously be set on the platen in such a way that at the decisive moment of action the type 212 on the platen roller no longer has a direct drive effect on the type lever 210. Through this the impact of the type lever 210 occurs solely through the energy supplied to it during the forward movement became. In this way, the recording medium can be handled very gently during the writing process achieve, but at the same time it is ensured that the kinetic energy of the type lever 210 is optimally used can be. For this it is only necessary to dimension the control slide 326 and 326a in such a way that during the forward movement of the type lever 210 the connection of the channel 342a is open to the outside with the outside space. In this way, can be different by inserting sized control slide 326 and 326a in the bore 344 or * 344a achieve control effects that the different requirements for writing speed, Writing quality and writing strength or possibly adapted to a certain phase shift between the call chamber and the callback chamber.

In Fig. 6, an embodiment of a writing mechanism according to the invention is shown, in which also a two-armed drive lever 436 in a type lever segment 448 is used, which can be attached to a bracket 449. The working principle of the type lever movement is correct thus corresponds to that described with reference to FIG. 5, with another embodiment of a selector rail device 472 can be used whose selector rails are adjustably fastened to the drive segment 454 by means of an intermediate layer 478 are. However, there is a special type of pneumatic drive provided with a continuously supplied Compressed air flow works and is attached to a holding plate 512. The compressed air flow is through a rotating control sleeve 500 divided into pressure pulses and each one of two different, with connection and Connecting elements 482 and 484 attached connecting lines 480 and 465, including the control sleeve 500 Has circumferential grooves 504, which enable the connection described in certain positions of the control sleeve 500. For this purpose, the circumferential grooves 504 are dimensioned so that they together with a control sleeve 500 in a control body 514 surrounding wall form channels which when the control sleeve 500 is rotated at inlet and outlet bores 506, 508, 510 move past in the control body 514 and in this way, connections between form these holes.

In the writing unit shown in Fig. 6 are in a drive segment 454 a call chamber 458 and a callback chamber 459 are provided which are connected to the connection lines 465 and 480 are in communication. The call chamber 458 is Via a transverse bore 461 and a channel 463 with the connecting line 465 connected. As with the ones previously described Embodiments are carried out in certain operational

Positions of the pneumatic drive, that is to say of the control sleeve 500, also here in each case a pressure equalization with the external pressure. To this end, the control sleeve 500 can be provided with at least one special radial bore 526 (FIG. 8), via which one of its circumferential grooves 504 is in connection with the outside space in predetermined positions via a channel provided between the control sleeve 500 and drive shaft 502. ^f

In the following, the function of the writing mechanism shown in FIG. 6 for a rotation of the drive shaft 502 will be described. First, it is assumed that the connection of the call chamber 458 with the 516 supplied via a line There is no overpressure, for which the control sleeve is in a position in which none of its Ümfangsnuten enables such a connection. Call chamber 458, however, is via channels 461 and 463 as well as line 465 connected to a bore 506, which in the starting position of the drive shaft 502 considered here via one of its ümfangsnuten 504 is connected to the outside space. This connection is blocked when the drive shaft 502 turns slightly and remains up to a rotational position of approx. 150 ° locked in relation to the starting position. During the turning range 0 ° to 30 °, the selector rail arrangement 472 is set in such a way that one formed with it There is a gap under an intermediate element 470 so that it can snap into it and is held on a magnetic strip 479 will. The intermediate elements 470 are held in their rest position shown in FIG. 6 on a magnetic strip 471, which in turn is attached to the type lever segment 448. A connection then takes place at a rotary position of 30 ° the call chamber 458 with the overpressure supplied via the line 516, through a circumferential groove 504 of the control sleeve 500, line 465, and channels 463 and 461.

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The overpressure in the call chamber 458 now causes one Actuation of that selection slide 469 »whose intermediate element 470 is precisely the one with the Whlschiene arrangement 472 is opposite. The selection slide 469 is by engaging in this gap a to the piston 446 leading hole 464 free so that the one in the call chamber 458 prevailing overpressure can move the piston 446 out of the position shown in FIG. 6 to the right. Of the Piston 446 acts on one arm 440 of a drive lever 436, so that it moves clockwise on its axis 438 (Fig. 6) can be pivoted and the type lever 410 from its magnetic strip 450 analogous to the already Embodiments described by means of the intermediate lever 426 mounted on an axle 430 and the teeth 434, 432, 428 and 414 is moved on its axis 416 to the platen 424 and the type 412 on the circular arc 420 moves and strikes the recording medium. During this process, the lower lever arm 441 of the Drive lever 436 moves a piston 447 from its position shown in Fig. 6 to the left, so that in the recall chamber 459 or in the bore 445 connected to it, a volume reduction occurs in front of the piston 447. With it during This time no compression occurs, the recall chamber 459 is connected to the control sleeve 500 via a circumferential groove connected to the outside space. On the other hand, a pressure equalization can take place upwards as soon as the lower part of the selection slide 469 has moved past the bore 445 and its constriction 464 is at the bore 445.

The overpressure in the call chamber 458 is maintained up to approximately the position 120 ° of the control sleeve 500, then it is interrupted by the corresponding circumferential groove 504 or control sleeve 500. The type lever 410 flies through his

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kinetic energy continues and completes its writing movement automatically, taking the piston 446 with it up to an edge 446a of its bore. A pressure equalization of the space in front of the piston 446 can take place past this edge. In addition, after a further rotation of the control sleeve 500, the call chamber 458 is reconnected to the outside space via the channels 461, 463 and the connecting line 465 as well as a circumferential groove 504 of the 500.

The second half of the revolution of the control sleeve 500 is used for Return of the type lever 410. For the recall chamber 459 operations similar to those already described for the call chamber 458 are now running. However, the movement now takes place of the drive lever 436 simultaneously with the return movement of the selection slide 469. For this purpose, the recall chamber 459 via the connecting line 480 and a circumferential groove 504 of the control sleeve 500 with the via the line 516 supplied overpressure connected. Before doing this, however, their connection to the outside space is removed when the device is turned 180 °. With a rotation position of 210 °, the pressure increase takes place, which is maintained up to about 300 °. This will make the piston 447 is moved to the right and thus the drive lever 436 is pivoted counterclockwise on its lower lever arm 441, so that the type lever 412 is returned to its rest position on the magnetic strip 450. At the same time, the selection slider is 469 is pushed upwards so that it is in the area of a recess 473 in the drive segment 454 coupled intermediate element 470 until it reaches the area of influence of the magnetic strip 471 and back on her is held in its rest position. Then the Bohrimg 464 in front of the piston 446 through the constriction 468 of the Selection slide 469 in the bore 460 connection formed with the outside space.

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In Fig. 7 the pneumatic and / or hydraulic drive is in a possible embodiment with a control sleeve 500 shown. This is arranged in a block 514 on the drive shaft 502 and can be continuous on it to be turned around. For example, it can be held at one end by a washer 522 while its other end is screwed and held by a nut 524. There are multiple bores in block 514 510 are provided, which on the one hand run radially to the control sleeve 500, on the other hand in its longitudinal direction. These Bores can be closed to the outside with sealing elements 518, depending on their function. In the top view are also the two lines 465 and 480 leading to the type lever drive in a section above the vertical bores 506 and 508 can be recognized. The entire drive assembly can be mounted on plate 512 which belongs to it for example, to the framework of a writing device.

8 shows the control sleeve 500 in a plan view. It is provided with four circumferential grooves 504, which are so arranged and are dimensioned with such a length that during one revolution with a suitable connection through the bores 510 results in a control of a writing process, as it is for the embodiment shown in FIG has been described. An example arrangement of the four circumferential grooves 504 are shown in FIGS. 9 to 12, which show the Show views of the sections IX, X, XI and XII from FIG. Another assignment of the circumferential grooves can also be used to each other and to the bores in the body 514 if other or special modes of operation of the writing should be realized.

In Fig. 13 the mode of operation of a writing unit with a pneumatic drive is shown, the

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Management example according to FIG. 6 and the drive according to FIGS. 7 to 12 described operations are reproduced. The representation applies to a rotation of the drive shaft 502 from 0 ° to 360 °. According to the working method described the call chamber becomes shortly after leaving the O ° position closed so that there is no connection to the outside area «Between 30 ° and 120 ° there is overpressure in the call chamber, which results in the writing process or the forward movement of the selected type lever. At about 150 °. the call chamber is opened again with respect to the outside space, so that the compensation and return processes described can take place. It is between approximately 180 ° and 330 ° the recall chamber is closed to the outside, so that its volume when the pressure increases between 210 ° and 300 ° enables the return of the type lever to its rest position. Between 330 ° and 360 ° there is pressure equalization or renewed preparation of the chambers for a new writing process, which is repeated accordingly from 0 °.

In Fig. 14 the overall view of a writing device is shown with a writing mechanism according to the invention works on a platen 624. The type levers 610 with the types 612 provided at their ends are so short that they can be mounted in large numbers in a circular arrangement ■ without complex mechanical Control and actuation elements are provided in the area of their pivot axes. Around the type lever 610 is a selector rail arrangement 672 is provided, the recesses 673 of which are arranged in the manner of a code-shaped distribution are that for setting on one of the type lever 610 a mutual rotation of the selector rails by one certain amount is required in the circumferential direction to form a gap for the selected type lever. These

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Displacement or displacement can be done with pneumatic, hydraulic or electromagnetic drive devices 675 take place, which are connected via coupling members 676 with lugs 677 on the selector rails.

In the lower part of Fig. 14 is the pneumatic or hydraulic To recognize drive, which can have one of the forms described and is assigned to all type levers 610 in common.

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Claims (20)

Claims Writing unit for the successive line-by-line application of characters on a recording medium, with type levers arranged next to one another on a circular arc-shaped pivot axis and acting on a common recording point by pivoting; characterized in that for generating the Pivoting movement of a selected type lever C ^ Q-) a hydraulic and / or pneumatic drive (98, 100) common to all type levers (10). Provided is the control assigned to all type levers (10) via a hydraulic and / or pneumatic control (58 * 60, 66, ^ 69) can be coupled in a l'iirkverbinduiig with a, from one of the 2tahl of type levers (10) corresponding drive elements (46), and that: Selector devices (72) are provided, which . according to the selection of a ^ © '"© i ^ igeni type lever% ^ 0) i in a predetermined position / are egbar BEV and, in this S.te * t ~ Lung the coupling of the drive (9B _t: 100); bring about with the drive element (46) of the selected typei ^ iebels by influencing the control (58, 60, 6.6, ^ 69) in the area of this drive element (46) :. 2. Writing unit according to claim 1> characterized in that the drive (98, 100) is a pulse drive, the Pressure or vacuum pulses with one of the writing speed or an integer multiple of Write speed corresponding frequency generated. 30 98 467 0697 3. Writing unit according to claim 2, characterized in that that the drive (98, 100) has a drive shaft (120) which via an eccentric arrangement (108, 118) is coupled to at least one pump device (100). 4. writing unit according to claim 3 »characterized in that that two pump devices (300, 300a) are coupled to the drive shaft (320) in such a way that they are out of phase, preferably work in push-pull. 5. writing unit according to claim 2, characterized in that that the drive has a drive shaft (502) which is provided with a sleeve-shaped with circumferential grooves (504) Rotary element (500) is coupled, wherein in a guide block (514) for the rotary element (500) connection points (506, 508, 510) for the connection of the circumferential grooves (504) with the control (458, 459 »469) on the one hand and with a pneumatic and / or hydraulic constant pressure source (516) on the other hand are. 6. writing unit according to one of the preceding claims, characterized in that the controller (58, 60, 66, 69) at least one with the arcuate pivot axis (16) the type lever (10) concentric pressure chamber (58) permanently connected to the drive (98 »100) has, the volume of which is given by each of one of the number existing type lever (10) corresponding number of selection slides (69) is limited, which by release by means of the selection devices (72) each in one Position can be moved in which they have a lock between the pressure chamber (58) and the respective drive element (46) release. 30 98 46/0697 7. writing unit according to claim 6, characterized in that zv / egg concentric pressure chambers (258, 259) are provided are, of which one (259) is permanently connected to the second drive element (247) for the type lever (210) and if there is overpressure, the type lever (210) may move into its rest position. 8. writing unit according to claim 6 or 7, characterized in that a connection of a concentric pressure chamber (58) runs with the outer space over the drive. 9. Writing mechanism according to claim 8, characterized in that the control slide is coupled to the drive shaft (320) (32-6 ,, 326a) are provided in the given Positions of the drive shaft (320) a connection of the concentric pressure chambers (258, 259) with open to the outside. 10. writing unit according to claim 7, characterized in that the connection of the concentric pressure chambers (458, 459) runs with the outside space over the rotary element (500). 11 ". Writing unit according to claim 10, characterized in that the rotary element (500) is designed as a sleeve, which is rotatably arranged on a cylindrical pin (502) and in which a connection (526) a Circumferential groove (504) with the space between the rotary element (500) and the pin (502) is provided, t. 309846/0697 12. Writing device according to claim 6, characterized in that a pressure chamber (58) is provided and that the respective selection slide (69), approximately in its rest position, connects the drive element assigned to it (46) releases with the outside space. 13. Writing device according to claim 12, characterized in that the pressure chamber (58) via the drive (98, 100) is connected to the outside space in its extreme negative pressure position. 14. Writing device according to claim 13, characterized in that the drive is a diaphragm pump (98, 100) is provided, which is coupled to an eccentric rotary drive (118, 120), the said connection in the negative pressure position generated via bores (122, 124) provided in it, which via a flexible connection (114) are connected to a bore (121) in the membrane (100). 15. Writing device according to claim 12, characterized in that the respective selection slide (69) as in a bore connected to the pressure chamber (58) (62) guided piston pin is formed between the ends of which a part (68) of reduced diameter is provided, in the area of which in the rest position Bores (64, 66) open into a working space for the respective drive element (46), on the other hand lead to the outside space. 16. Writing device according to one of the preceding claims, characterized in that each drive element (46) is assigned a drive lever (36), 309846/0697 222187 which is positively coupled to the type lever (10) and that the selection devices (72) can each be stopped in a selected position for such a time are that the respective negative pressure pulse a return of the drive element (46) to its rest position causes. 17. Writing device according to claim 7, characterized in that each first and second drive element (246, 247) is assigned a two-armed drive lever (236) which is positively coupled to the type lever (210) is. 18. Writing device according to claim 10 or 11, characterized characterized in that the first and second concentric Pressure chambers (458, 459) are the end spaces of a bore in which a piston pin-shaped selector slide (469) is arranged that both pressure chambers (458, 459) with Uinfangsnuten (504) of the rotary element (500) are in connection, and that in the two end positions of the selection slide (469) each one of the two drive elements (446, 447) in the space above Work surface is connected to the outside space. 19. Writing device according to claim 18, characterized in that the connections to the outside space a part (468) of the selection slide (469) with reduced Run past the diameter. 20. Writing unit according to one of the preceding claims, characterized in that the drive element (446) moving the type lever (410) in the forward direction is a piston arranged in a bore, which is connected to its in a predetermined working position Releases the work area to the outside area. 309846/0697 Blank page