DE1915926A1 - Printhead shifting device - Google Patents

Description

PATENT LAWYERS I U I DIPL-ING. HANS BEGRlCH · DIPL-ING. ALFONS WASMEIER REGENSBURG 3 LESSINGSTRASSE 10 Patent attorneys, Beschich Waimeier, 8400 Regmiburg 3, Postfach 11

To the

German.Patent Office

8 Munich 2 Zweibrückenstrasse 12

Telephone 09 41/31055 Bayer. State Bank, Regensburg 507 Postal checking account: Munich 89369 Telegrams: Begpatent Regensburg

Your sign Your message from

Please indicate in the answer Our sign

L / p 6576

t ° o March 17, 1969 W / He

LITTON BUSINESS SYSTEMS, INC., 550 Central Avenue, Orange,

New Jersey 07051, U.S.A.

Printhead shifting device

The "invention relates to printing devices and more particularly to a novel device for "displacement of a print head in such a way that one or the other of two writing tapes is moved on the printhead into the effective printing position. .

Known devices of this type are based on a single one
Mechanism for operating an arm for raising and lowering a type component between one of two pressure positions. Solenoids and other such mechanisms are often used here; however, since only one mechanism is used, it is often the case that damage is caused to the mechanism by continuous operation due to fatigue.

909843/1173

BATH ORIGINAL

I7.5.I969 W / He - 2 - L / p 6576

The applicant has already proposed a resilient drive tongue Provide, in the beginning potential energy is stored when the tongue by strong excitation of a Electromagnet is deflected. If the magnet is de-energized, the tongue is released and vibrates at its! * Resonance frequency, so that the energy to operate a print head is generated. The circuitry that reacts to de-excitation signals in the magnet responds, works in time so that it takes effect when the kinetic energy of the tongue oscillates back is about zero, and the magnet is re-energized at lower energy to complete the return movement of the tongue and the full potential energy is stored.

The aim of the present invention is to improve such a previously proposed device and in particular the displacement of the print head can be accomplished quickly, safely and with little energy expenditure in a particularly expedient manner.

According to the invention it is proposed that a pivot point pivotable arm is connected to the printhead so that it is between a first and a second set of the head of characters that a first device is provided near one side of the arm and one side of the pivot and that a first pretensioning device is on the opposite side of the pivot point with respect to the first device is arranged which biases the arm against the first device, when actuated so that the printhead shifts from the first set of characters to the second set of characters.

The device thus shifts the height of a print head in such a way that one of the two writing tapes is in the printing position got. A pivot arm is connected to a vertical shaft that receives the printhead. The arm turns into a

BATH ORIGINAL

Ö09I43 / 1173

May 17, 1969 W / He - 3 - L / p 6576

raised or lowered position rotated to the respective Bring the writing tape into the correct printing position by actuating one of the two oppositely arranged solenoids will ·. that are above and in the middle of the arm and on are attached to one side of the pivot point. Two springs working in opposite directions work together with the solenoids, which are connected to the other side of the pivot point. These springs are arranged so that when the arm of the one is moved into the other position by actuating a solenoid, the opposite spring is tensioned so that it stores energy and, when the other solenoid is actuated, cooperates with that solenoid and preloads the arm and moves the printhead to its new position.

The invention is explained in more detail below in conjunction with the drawing using an exemplary embodiment. the Figures show:

Figures 1 and 1A are a front elevational view of the machine embodying the present invention Has facility,

Fig. 2 is a side view of the machine from the left,

Fig. 3 is a plan view of the power tongue and associated Magnets along the line 3-3 of FIG.

4 shows a side view of the printing unit from the right,

Figure 5 is a plan sectional view taken along line 5-5 Fig. 4,

6 is a plan view of the printing unit,

90984 3/1173 bad original

17.?.1969 W / He - 4 - L / p 6576

Fig. 7 is a cross-sectional view taken along line 7-7 of Fig. 6;

Figure 8 is an enlarged fragmentary view of the printing drum and registration device for the drum, and

Pig · 9-9A and 10 are graphic representations of the operation of the Power device. · *

According to FIGS. 1 and IA, the machine according to the present invention Invention left and right side frames 1 and 2 in which a non-displaceable counter-pressure roller 3 is rotatably mounted. A cross bar 4 is located towards the front in this side frame attached, while behind the rod 4, the frame receive a rail 5, which together to support the transverse movement serve a displaceable carriage C on which the character printing drum 6 is attached.

With the left side of the carriage is over the pin 7 a flexible steel band 8 attached, the first around a pivotable on an arm 10 attached to the left side frame 1 deflection roller 9 and then over the front of the Machine and is guided around a pulley 11, which is rotatable on the arm 12 attached to the right side frame 2 at ·! · is brought; then it will put the tape on the drum 15 wound up with the shaft 14 of a step change motor 15 is attached. Furthermore, a second drum 16 is connected to the motor shaft 14, on which a similar tape 17 is wound is, which is guided around a pulley l8 and attached to the right side of the printing carriage C via a pin 19 '. Depending on certain, selectable pulse signals that are sent from a control source or a computer in a per se known * Are recorded manner, the motor 15 is used to move the printing carriage C by predetermined distances either after right or left.

BADORIQIMAL

909843/1173

• 1915928

17 · .3.1969 W / He - W. L / p 6576

The Drucksahlitten C has thin support frame 20 (Fig. 4-7), the front end of which is slidably mounted on the rod 4, and the rear end has rollers 21 which run on the rail 5 .. The frame 20 is with two The above approaches 22 are provided for receiving the ^{pivot pins 23, which are angeadnet within the forked arms 24 f} , which represent the lower end of a U-shaped frame 24. Within the upper arm 24 ″ of the frame, the upper part of a shaft 25 is rotatably mounted, on which the character or printing drum β is attached. If desired, the drum 6 and shaft 25 can consist of one piece, for example made of cast nylon. The lower end of the shaft 25 is widened and forms a sleeve for receiving the spherical end 26 of a shaft 27 which extends upwards from a step change motor 28; the motor 28 is received on the underside of the carriage frame 20. A pin 29 extends through the ball 28 and is received in an elongated, vertical slot 30 Sm at the lower end of the printing drum shaft 25, thereby drivingly connected to the motor shaft 27 such that the printing drum can be moved up and down.

In order to achieve this upward and downward movement of the printing drum, two rearwardly extending levers 3I arranged at a distance from one another are each pivotable at 32 on an upwardly projecting part 20 ^! of the carriage frame 20 attached. The rear ends of each lever 31 are forked so that they encompass the upper and lower sides of an enlarged circular disc 33 which has a stop on the shaft 25. A metal block 34, which is fastened so that it runs between the pairs of arms 31 and is movable therewith, serves with its arms as an anchor between two oppositely arranged magnets 35, 36 which are mounted on the frame part 20 ^{f of} the printing carriage C. . If -both magnets have their-

909043/1173

BATH ORIGINAL

19Ϊ5926

May 17, 1969 W / He - F- Vp 6576

assume de-energized state, a pair of balanced springs 37 1 37 'so that the lever 31 and thus the printing drum 6 are held in a central position, so that one or the other of two rows of printed characters around the circumference of the drum 6 are arranged, are brought to the print line with respect to the roller 3. It is intended, however, that one or the other magnet should normally remain energized in response to a preceding final pulse signal transmitted to it by known input devices.

From the above it follows that with simultaneous de-excitation of one of the magnets and excitation of the other corresponding to one selected pulse signal the armature 3 ^ either upwards or down until stopped by the magnet that has been energized. The lever 3I shifted either clockwise or counterclockwise by position 32 depending on such pulse signals and raises or lowers the shaft 25 with the print head 6, thus selectively one of the rows of printed characters it is brought into pressure registration with the roller 3.

In such processes, the potential energy contained in one of the two oppositely acting springs 37 * 37 ^T decreases, while the potential energy of the other spring increases, with the result that the lever 31 with the armature 34 for one of the two directions of movement is spring-loaded.

This arrangement of the spring balancing and the use of caps 38 made of appropriate anti-magnetic material, e.g. Tetrafluoroethylene, known as TEFLON, is used on the core of every magnet to hold a

009843/1173

I7.5.I969 W / He -Je - L / p

to achieve faster response of the above devices to any input pulse signals.

A selection of a desired character to be printed is activated by selective advancement (backwards or after forward) of the step change motor 28 achieved in such a way that j the drum 6 from the immediately preceding font. area selection position in a different character pitch accordingly the special input signals from the main I. Control devices are included, is set.

The novel device for achieving a forward or backward pressure stop movement of the character printing drum 6 will be described below.

Deflection rollers 42, 4j5 are attached to a pair of lugs 4o, 4l which are arranged at a distance from one another and which are fastened to the frame 20 of the displaceable carriage C). Between j the approaches 22, which receive the frame 24 on which the! Printing drum ό is attached, a sliding block 44 is guided, which has two spaced stops 45, 46 which extend with respect to the mutually cooperating, offset arms 47, 48 to the rear; the arms 47, 48 stand from the frame 24 downwards. An elongated recess 49 allows the block 44 to the block, the motor shaft 27 is spread _Ä while a rod 50 which is fixed between the stops 45 46 secured to one end of a spring 51 with it. The other end of the spring 5I is attached to an extension 52 which is arranged in the frame 20 and serves to preload the block 44 towards the rear. Two springs 61, each one, is held in a corresponding recess in the rear] surface of the stops 45, 46 at each end which are \ connected to the associated · arm 47j 48 and at its other end with a rod 62, serve to the yielding '

909843/1173

BATH ORIGINAL

I7.3.I969 W / He - / - L / p 6576

Pre-tensioning the arms against the front surface of the stops. The front end of the block 44 is forked and forms an upper; and lower bearing support for a shaft 53j of ^a uf a guide roller 54 is mounted rotatably between the Lagerstützar.

According to FIGS. 1 and IA, a flexible steel belt 55 is over a Bolt 56 is attached to the rigid arm 12 of the machine and runs to the left around the front face of the pulley 4j5, then to the rear around the pulley 54, to the front around the ■ pulley 42 and again to the left around the stationary pulley 57, and is then at the opposite end with the ab- fc located end of a resilient tongue 58 (Fig. 2 and 3) attached, the opposite end of which is attached to the base plate -59. The tongue shows the armature for two parallel electromagnets 60, which are attached to the base plate 59, and is designed so that they a printing process of the drum in'der ' in the manner described below.

If the machine is switched on and the magnets 60 have thus been excited, the tongue 58 is deflected and held by the magnets in such a way that the belt 55 is released. This makes it possible that the spring 5I holds the slide block 44 with the pulley 54 in a rearward position, whereby. any slack is taken, otherwise the band would get 55 through \ the deflection of the tongue 58 to. At the same time, the springs 61 have the effect that the frame 24 with the print head 6 is held in a counterclockwise position.

The magnets CO can then according to a pulse repetition rate, as is known from per se control " facilities is transferred, de-energized and re / energized. So that a Resv: magne-; isrnus in the magnet βθ a release of the Tongue 5 & not delayed, is the side of the tongue that denotes the Magnet 6ü is facing - with an anti-magnetic substance

90984 3/1173 ^ßAD

17.J.1969 W / He. - & - . L / p 6576 ·.

e.g. tetrafluoroethylene coated. If the Magnet 60 releases the tongue 58 and gives the belt 55 a leftward movement (FIG. 1). Will the opposite end of the tape 55 * as described above, held, the pulley 54 is forward moves, which corresponds to a movement to the left in FIGS. 5 and β, and displaces the slide block 44 with it so that rapid clockwise rotation of the frame 24 and the Print head 6 is exerted. During such a process, the tongue 58 has reached its maximum speed and is then delayed in a characteristic way. The band 55 pulls the sliding block 44 only partially forward, however following this, an acceleration, which is thereby given to the frame 24 and the print head 6, causes the print head is moved further and the usual writing tape 63 at each Recording form, as it is used between belt and roller 3, acted upon. During this latter part of the pressure stroke the delay of the tongue 58 slows down the movement of the Sliding block 44 and the print head can strike freely, so that no bounce is transmitted back to the tape and thus a Damage to the tape is avoided.

During the return stroke of the vibration of the tongue 58, the belt 55 becomes relaxed, causing the spring 5I to reverse the slide block 44 can lead, while the springs oil, which by the. Rebound of the parts and by the increased, in them during the pressure stroke stored energy are supported, the frame 24 and the print head 6 return counterclockwise to the normal position.

From the above it follows that the tongue 58 by the fact that it acts like a leaf spring, oscillates at a resonance frequency, but is limited to one oscillation period, i.e. different from the Magnet 60 lifts off when these are de-energized, and tape 55 on a forward stroke or pulls away from the magnets. During the return stroke of the tongue 58, the period is ended

309843/1173

BATH ORIGINAL

"-" "" "1915929

3/17/1969 W / He - / f- L / p 6576

The tongue is acted upon again by the magnet βθ when it is excited, namely by a control circuit that is switched on to the magnet at a certain point in time before the tongue has completely returned, and which builds up the magnetic field to such an extent that the tongue 58 a short remaining distance to the normal position is drawn, the associated parts which are actuated by the belt 55 also return to their normal position with a minimum of bouncing or impact.

In order to better understand certain processes and advantages of the device according to the invention, reference is made to the graphic representations according to FIGS. 9, 9k and 10, which are described below.

Fig. 9 shows the force exerted by the magnets 60 for deflection the power reed 58 due to an initial potential " energi © storing stroke for the tongue and related to the Required force of the magnets for subsequent deflections the tongue is given up.

Assuming that all energy is switched off at the beginning, the tongue 58 would not experience any deflection, as is shown at the point "zero deflection" on the X coordinate. ^; '-: · An initial, short-term high current force of such magnitude that it is sufficient to saturate the magnets sufficiently to deflect the tongue 58 to close the initial gap G, depending on the activation of the energy or in any other Wise induced and is represented by the line of high current force, which runs continuously above the line of force R, which represents the deflection condition for the tongue 58, and is thus continuously higher.

BAD ORlGIISfAL 909843/1173

3/17/1969 W / He - TU - L / p 6576

AA

Immediately following the maximum force of high current at F- on the y-axis, it is intended that the maximum magnetic force on the magnets ^{should fall on a point P 1} on the graphic representation. This reduced force, however, keeps the magnets sufficiently energized that they hold the ainge 58 at its -maximum deflection point + D. Subsequently, each time the magnet 60 is de-energized, the tongue 58 is released, and due to the inherent potential energy, the tongue shifts at its resonance frequency to the point: -D and indirectly back to the point + D ^f , as shown in dashed lines on the graphic representation indicated. At this point, a circuit arrangement known per se, which has a monostable multivibrator OSM (FIG. 9A), causes the magnets 60 to be energized again, as a result of which the magnets initiate the opening closing movement of the tongue 58 towards the magnet. complete, as shown by the strong line from point + D ¹ to point + D on the drawing.

From this and from the graphic representation it follows that the magnetic force curve of the slight current intersects the line of force R, which represents the condition for the tongue approximately on the line + D ¹ , and below the force R for the tongue e falls along a substantial part of the line R. Thus, the kinetic energy of the moving tongue is used during this portion of the time, and a reduced energy is therefore required for the magnets 60 to move the tongue 50 through the remaining short gap, which is defined by the line + D ^! to + D, and to introduce the full potential energy into the tongue. Furthermore, a greater spread is possible for the time behavior for renewed excitation of the magnet

■ 9-09843 / 1173- BAD original

W / He - ^ t - L / p 6576

ft

Pig. 10 shows a sinusoidal graph that appears the speed curve of the tongue 58 with a time shift curve and which shows how the tongue itself springs during the pressure oscillation, and how the shock that occurred before has been described, is kept to a minimum when actuating the tongue. Furthermore, FIG. 10 shows in connection with Fig. 9A how the tongue force actuator works, to the printing devices in a certain time sequence with any input repetition from the main control devices to operate.

Assuming that the magnet 60 is energized, the tongue 58 is held by the magnets at the maximum potential energy shown at + D on the y-coordinate. The stationary state of the tongue at zero speed is shown on the junction of the xy coordinates. When the tongue 58 is released following de-energization of the magnets 60, the tongue is shifted to the zero deflection point A on the tongue displacement curve. At this point the tongue has reached the maximum speed shown on the speed curve. The tongue 58 now reverses its force when it moves beyond point A to point -D- ¹ , during which the speed curve again comes to zero. The printhead 6 continues in its forward stroke stroke so that an imprint is obtained during this period of movement of the tongue 58. If one now ^{returns from point -D 1} , the tongue curve intersects the x-axis at the maximum return speed and its force is reversed again, and goes through point + D ^f ; at this point the speed becomes zero again and the "entire kinetic energy has now been converted into potential energy in the tongue 56".

At + D ¹ , the tongue 58 is not yet completely with the magnets

60 returned, which is at the point + D on the graphic display position is indicated. At this point / acts like further

909843/1173

^ßÄD

I7.3.I969 W / He - ^ - ■ ^L / ^p

has already been indicated above, a corresponding time delay circuit OSM with a monostable multivibrator a renewed excitation of the magnets 60 to complete the deflection of the tongue 58 from point + D ¹ to point + D. The velocity curve shows that during this brief movement and period of time the velocity of the tongue 58 generated by the magnets 60 is so low that there is very little impact when the tongue 58 strikes the magnets 60; this avoids noise and shock, as well as possible breakage of the belt 55.

Since the build-up time required to excite the magnets βθ is known, it is possible to place the excitation vagang fairly early on at the point + D ¹ on the drawing.

From the above description it follows that while repetitive, incoming signals that are offset by a certain time interval, e.g. from a corresponding Main control device, magnets 60 are de-energized each time to release a power reed 58 in order to be successive through the reed To achieve printing operations, and that the magnets are timed by known control switching devices so that they are re-energized in chronological order with such input signals so that the potential energy is stored again within of the tongue 58 in a corresponding time for each subsequent Release is completed.

Corresponding known feedback circuits that. need not be described here / can be switched on there, vjo it to control the tent switching processes for an input signal appears required in the printer from the main control device.

909843/1173

BATH ORIGINAL

Claims (1)

17O.1969 W / He -.! Rf- L / p 6576 Claims; Printhead shifting device for shifting one or the other of two writing tapes on the printhead into the effective printing position, characterized in that an arm (31) pivotable about a pivot (32) is connected to the printhead (6) in such a way that it moves the head between a first and second sets of characters that a first device (36) is provided near one side of the arm (31) and one side of the pivot (32) and that a first pretensioner (37) is on the opposite side of the Pivot (32) is located in relation to the device (36) 'which biases the arm (31) against the first device (36) when actuated so that the printhead (6) moves away from the first set of characters shifts to the second set of characters. 2. Device according to claim 1, characterized in that a second device (35) on the same side of the arm (31) as the first pretensioning device (37) is arranged, and that a second pretensioning device (37 ') on the same Side of the arm (31) as the first device (36) is arranged. ·. ' 3. Device according to claim 1 or 2, characterized in that that the first and second biasing devices (37, 37 ') are two Have springs with the arm (31) on opposite Sides of the arm and on the same side of the pivot point (32) are connected to one another, and that the first and second devices (36, 35) have two electromagnetic arrangements, which are excitable and de-excitable and those with the arm (31) on ■ opposite sides and on the opposite side of the pivot point (32) with respect to the springs, BAD ORfQJM _AL 90S843 / 1173 3/17/1969 w / He- yr- l / p 6576 with a deflection of the arm (Jl) by an electromagnetic Arrangement (35-1 or 36) the spring on the same Side of the arm (31) is tensioned and thus energy is stored in the spring / so that when one is de-energized, electromagnetic Arrangement and when the other is excited the spring releases its energy and the arm against the latter electromagnetic Pre-tensioning arrangement. 4. Device according to claim 1 or one of the following, characterized characterized in that the print head (6) is arranged on a shaft (25) and is in communication with the arm (31) by engagement with the shaft (25). 5 · Device according to claim 3 or 4, characterized in that the arm (31) runs horizontally, that the electromagnetic • arrangements (35 * 36) perpendicular to the arm (31) and with respect to the pivot point (32nd) on the same Side like the print head (6) are arranged, and that the pivot point (32) and the springs (37, 37 ¹ ) are also provided approximately perpendicular to the arm (31) and with respect to the pivot point on the opposite side of the electromagnetic arrangements. 6. Device according to claim "3 or one of the following, characterized in that the electromagnetic arrangements (35, 3 &) Solenoids are. 7. Device according to claim 1 or one of the following, characterized in that the print head (6) has a circular disk (33) and that the first and second sets of characters parallel bands with printed symbols included. 8. Device according to claim 1 or one of the following, characterized characterized in that the shaft (25) "has a stop (33) which cooperates with the arm (31) in such a way that Arm (31) and print head (6) are connected to one another. 9 0 9 8 4 3/1173 BATH