DE1245626B - Drive device for print hammer in printing units for data processing systems - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

PATENT LETTERING

Int. Cl .:

G06k

German class: 42 m6 - 15/02

Number:

File number:

Registration date:

J218 () 7IXc / 42m6
May 22, 1962
July 27, 1967
15th February 1968

Display day:

Issue date:

The patent specification corresponds to the patent specification

The invention relates to a drive device for print hammers in data processing machines a pretensioned drive spring assigned to each print hammer, which after release against the assigned, Hit the spring-loaded print hammer.

In the known high-speed printers for data processing, the type carriers are continuously driven and the printing of a desired type is achieved by the fact that the individual printing points assigned print hammers for the imprint of the type are then driven as soon as the dem Line text corresponding type appears at the relevant printing point. To at the high print speeds To get the correct type to be printed, the line text to be printed is stored in a buffer memory in known printing devices stored, in which a memory location is provided for each print location. For printing it will Read the type characters in front of each printing point and match them with those entered in the memory Data compared for the line to be printed. As soon as this comparison shows a pressure point between If the memory and type carrier match, pulses are used to create the pressure points assigned print hammers driven. In this way, depending on the design of the printing unit The type of the type carrier located in front of or behind the printing material is posted and ready for printing brought. The high printing speed of z. B. 600 lines per minute requires an extremely fast hammer function, which has to be precisely timed because of the working speed of a printer depends on the speed and the temporal accuracy of the drive device for the print hammers. Both characteristics essentially influence the legibility and quality of the print image.

Various devices have become known for driving print hammers in printing units for data processing systems. These devices, however, have deficiencies which limit the performance of the printing units and also have a detrimental effect on the reliability of the printing units due to their large number of components. A cam drive device requires e.g. B. a large number of precisely shaped cams and selection and control means to prevent the triggering of unwanted print hammers alone. Drive devices which use working magnets to drive the print hammers are just as complicated, since the same because of the high drive device for print hammers in
Printing units for data processing systems

Patented for:

International Business Machines Corporation,
Armonk, NY (V. St. A.)

Representative:

Dipl.-lng. HE Böhmer, patent attorney,
Böbüngen (Württ.), Sindelfinger Str. 49

Named as inventor:
Ronald Dean Nelson,
Donald Karl Rex, San Jose, Calif. (V. St. A.)

Claimed priority:

V. St. v. America of May 29, 1961 (113 201)

Force requirements for the work of the magnets and because of the circuitry required to overcome them the effect of magnetic remanence and induction special and extensive switching measures require. Drive devices working with spiral springs have also become known, in which the coil springs have always remained in working contact with the print hammers. Accordingly had to use the reset and locking devices common to all pressure hammers very bulky and cumbersome, as these organs take the combined force of all hammer drive springs have to counteract.

The invention avoids the explained disadvantages of known devices and combines the advantage the simple construction with the safe and fast function of the drive of the individual pressure points associated print hammers in that each drive spring is designed as a spring package, in each of which a spring is provided with a rebound of the hammer damping approach, and that all spring assemblies are attached with their clamped end to a cam-controlled rocker that are in synchronism with the printing process

809 503/255

for one print line and in a regular sequence with a second cam-controlled rocker that engages the free ends of all spring assemblies is driven to return all the hammer that has slipped on the drive arms during the printing process free ends of the drive springs on a path bypassing these arms for re-manufacture the drive connection between the spring ends and the arms and to bias the Spring assemblies, the drive for the individual being designed as anchor plates for holding magnets Print hammer only becomes effective when released by the associated holding magnets. The inventive Drive device accordingly provides a spring drive in which the drive spring becomes ineffective after the push hammer hits, so that the hammer with the help of light damping springs can be transferred to its starting position. In this starting position the hammer is held by an associated holding magnet, its excitation at the time of the print hammer selection is interrupted by an impulse, thereby making compared to the known with working magnet working drive device a fast and time-accurate mode of operation is guaranteed.

But it is also known in a type printer with a rotating type wheel, a release magnet to be provided, which has fallen off in its rest position and a pretensioned leaf spring due to its being excited releases, which moves the print hammer against the surface of the type wheel. On this print hammer attacks a helical spring acting as a return spring. But with this type printer there is no spring dampening the hammer return movement, but this is the case with the subject matter of the invention is provided and is absolutely necessary for hammer attacks carried out in the manner of a whiplash. In the absence of such a damping spring, namely, the print hammer can be uncontrollable Get vibrations, which on the one hand can generate additional type stops, through which a clean, sharp print image is thwarted, and on the other hand the time until it is finally achieved extend the starting position of the print hammer, thereby increasing the operating frequency of the print hammer and thus the printer's printing performance will be reduced.

Details of the invention are given below on the basis of an exemplary embodiment illustrated in the figures described. It shows

F i g. 1 is a perspective, partially sectioned view of a printing device with FIG Line direction moving type carrier and assigned drive device for the print hammers,

F i g. 2 the side view of a pressure point with the associated drive device for the print hammer after the stop and return of the same and

3 shows the same side view as FIG. 2 with the hammer in readiness for printing.

The in F i g. 1 to 3 printer shown has the usual platen 10, a z. B. in lines direction movable type carrier 11 as well as the print hammer 12 assigned to the individual printing points with the Drive devices. When moving the type bar, if the types in the individual printing points with the corresponding details of the line text to be written ^ the den Make assigned hammer selected and driven. Every print hammer has a holding magnet 13 and a return spring 14 assigned. The individual print hammers 12 are with their slots 16 rotatably mounted on a continuous shaft 17. For resetting the individual hammers lies down the return spring 14 against the finger attachment 18 provided for this purpose. Each individual is responsible for the drive Hammer equipped with a downwardly directed drive arm 19.

The hammer drive device, designated as a whole by 15, contains one for each hammer Flat spring package 21, which are fastened together in a rail 22 acting as a rocker.

Each spring package 21 has a number of leaf springs 26 to 29 with progressively decreasing lengths, only the spring 27 is bent at its free end to form an elastically effective stop 31. This The stop 31 projects beyond the spring 26 of the spring assembly and lies in the area of action of the drive arm 19 his assigned hammer. One of the arms 33 and serves to reset the spring assemblies 34 carried stop swing arm 32. The drive of both the swinging rail 22 with the spring assemblies 21 and the stop rocker 32 are carried out by cams on the clockwise driven Camshaft 39. The cams 35 and 37 on the camshaft 39 are the arms 24 and 25 for assigned to the oscillating rail 22 and cause the camshaft 39 to rotate when the camshaft 39 is rotated the cam follower rollers 41, 42 mounted in the arms 24 and 25 cause an oscillating movement of the rail 22 with the spring assemblies 21. The stop rocker 32 carried by the arms 33, 34 is supported by the Cams 36, 38 driven, which via the associated cam follower rollers 43, 44 on the support arms 33, 34 act. The cam follower rollers 43, 44 with the cams 36, 38 in Drive connection held. The drive connection of the cam follower rollers 41, 42 of the arms 24, 25 with their drive cams 35,37 is due to the reaction of the spring assemblies 21 on the arms 24, 25 ensured. The axis 17 for the print hammer as well as the axis 23 and the camshaft 39 and the return springs 14 for the individual print hammer are in the frame 47 of the printing unit stored accordingly.

The drive device for the individual print hammers according to the invention works in such a way that the free end of the spring 26 in the rest position of the spring assembly 21 lies under tension against the drive arm 19 of the associated hammer 12, the force exerted by this spring in the clockwise direction from the holding magnet is intercepted, against the pole faces of which the pressure hammer acting as an anchor plate lies (Fig. 3). The force of the holding magnet and the tension of the spring are dimensioned so that in the In the rest position, each holding magnet 13 holds its associated hammer 12 against the action of the drive spring 26. The release of the under spring tension standing hammer 12 for the imprint of a type at the moment in which from the type bar the correct type required for the imprint is passed to the corresponding printing point is done by canceling the holding effect of the magnet 13 by adding power to it Winding 48 is interrupted. Once the

Holding magnet current is de-energized, the associated print hammer 12 is energized by the pretensioned drive spring 26 driven in the direction of the platen accelerated. With this movement it slides the tip of the drive spring from the lower end of the drive arm 19 and lies against the stop rocker 32 (Fig. 2). The acceleration given to the hammer causes that in front of it The type of type bar 11 located there for printing against the printing surface or platen ίο is beaten. After the type hits the platen, the hammer hits the opposite side clockwise towards the holding magnet

13 back. During this rebound, the drive arm 19 of the hammer comes into the area of the elastic Stop 31 of the spring 27, whereby the hammer is braked and the hitting of the same is damped against the holding magnet. The return spring resting against the shoulder 18 of the hammer

14 counteracts the elastic stop 31 so that the same at a small distance from his Holding magnet is held.

After completion of a printing process for one line, the holding magnets 13 are excited again. Subsequently all drive springs 26 are simultaneously reset with the aid of the camshaft 39. With drive of the camshaft 39 in the clockwise direction, the oscillating rail 22 initially leads a Oscillating movement that moves the spring assembly downwards and to the left. At the same time, the Stop swing arm 32 is also guided in a partial swinging movement downwards and to the right. During this movement process, the free ends of the drive spring 26 are attached to the lower Tips of the drive arms 19 of the hammers moved past, so that now the return springs 14 their assigned print hammers can move against their holding magnets, so that they act as an anchor plate Print hammers lie against the pole faces of the holding magnets and are held by them. As the camshaft 39 continues to rotate, the oscillating movement of the rail 22 is continued, which now leads all the spring assemblies 21 with the drive springs 26 upwards and to the right. the Upward movement goes so far that the individual drive springs 26 are in the area of the drive arms 19 reach the print hammers and establish a drive connection with them (FIG. 3). Subsequently As a result of the further rotary movement of the cam shaft 39, the stop rocker 32 returns to its basic position back (FIG. 1), while the individual print hammers 12 are pretensioned by their associated drive springs 26 to make them ready for printing will. A single rotation of the camshaft 39 driven by a motor thus, of the cams attached to this shaft, the two rockers 22 and 32 of the drive device reset, so that after printing a line all print hammers through the also returned drive spring assemblies 21 are immediately brought into their preloaded position and thus for ready for a new line to be printed.

Claims (2)

Patent claims: 1. Drive device for print hammers of data processing machines with each Pre-tensioned drive spring assigned to the print hammer, which after release against the assigned, hit the spring-loaded pressure hammer, characterized in that that each drive spring is designed as a spring assembly (21), in each of which a spring (27) is provided with a rebound of the hammer damping approach (31), and that all Spring assemblies (21) with their clamped end on a cam-controlled rocker (22) are attached, in synchronism with the printing process for a print line and in time regular sequence with a second cam-controlled, at the free ends of all spring assemblies attacking rocker (32) is driven to return all during the printing process on the drive arms (19) of the hammers (12) slipped free ends (26) of the drive springs on a path bypassing these arms (19), for re-establishing the drive connection between the spring ends (26) and the arms (19) and for preloading the spring assemblies (21), wherein the drive for the individual print hammers (12) designed as anchor plates of holding magnets (13) only when released by the associated ones Holding magnets (13) becomes effective. 2. Drive device according to claim 1, characterized in that for the storage of all Print hammer (12) an axis (17) is provided on which each print hammer (12) by means of a slot (16) is pushed on, the open side of the slot (16) being the type carrier (11) is facing, and that in the vicinity of the slot (16) one force each opposite to the direction of the hammer movement causing the type stop, designed as a leaf spring retaining spring (14) rests on each hammer (12). Publications considered:
German Patent No. 689,963;
U.S. Patents No. 2,077,963. 2,799,221. 1 sheet of drawings 709 618/246 7. 67 ® Bundesdruckerei Berlin