DE1179228B - Line printer - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Boarding school KL: B 41 j

Number: File number: Registration date: Display day:

German class : 15 g - 24

St 17136 VIIb / 15 g
November 19, 1960
October 8, 1964

The invention relates to a line printer. Such printers are in the relevant Technology has been known for some time in the form of mosaic printers where the characters can be composed of individual points, e.g. B. from a 5 x 7 point grid. For the production Various solutions have been proposed for the signs. There is a simple solution in combining 35 wires to a print head and bundling the wires so that their The ends occupy an approximately flat surface, the size of which corresponds to that of the characters to be printed. The wires can strike the pressure surface independently of one another from this surface will. There are basically two options for selecting the wires required for printing: Either you operate each wire with its own electromagnet or you press it entire wire package against a perforated template, which only contains the wires that are not required for printing lets pass. Instead of the perforated template, you can also use a template with a specific arrangement use of surveys. The stencil is then adjusted so that in each case the one to be printed Wires face elevations; then the template is pressed against the wire package. In order to be able to print several characters at the same time, a corresponding number of Arrange print heads side by side. Since the characters are generally closer to one another should, than you can attach the print heads with their actuation mechanism, goes a known proposal to provide several heads, each of which has several printing positions assigned. The imprint is then carried out at the same time. After printing, they will be in a line arranged print heads shifted sideways and so the next characters in the same line printed.

Instead of printing the m · «dot matrix in its entirety, it can also be built up line by line. The print heads then only consist of m or η wires. Here, either the writing head can be moved over the paper or the paper can be transported past the writing head. The pressure wires are actuated by individually controlled electromagnets. In this case, too, several writing heads can be arranged in order to build up several or all characters of a writing line at the same time. The line-by-line structure of the characters is favorable because the paper can be moved continuously past the heads and so can line printers

Applicant:

Standard Elektrik Lorenz Aktiengesellschaft,

Stuttgart-Zuffenhausen, Hellmuth-Hirth-Str. 42

Named as inventor:

Dipl.-Ing. Helmut Gröttrup, Pforzheim

comes at very high speeds. However, since the actuating magnets are a certain, not along the writing line, the characters cannot be so close to one another print or make it as small as it would be possible for good legibility. By staggered arrangement of the print heads in several lines one could counteract this disadvantage, but this means a considerable effort and an enlargement of the printer.

In a known line printer which builds up the dot matrix of the characters to be printed line by line the pressure elements designed as flat levers are arranged on a common shaft, of which they are forcibly moved up and down and the one at both ends, for example is forced into this movement by two electromagnets. The selection of those required for printing Pressure elements are carried out by pivoting by means of an electromagnet assigned by a pressure element. This well-known Printer has the disadvantage that, in the case of wide writing lines, there is no uniform imprint of all printing elements is guaranteed. In addition, bruises as a result of the Forced movement imprints occur in unwanted places.

On the other hand, a printer has already become known in which the pens, one cause punctiform imprint, be moved back and forth by means of electrostatic force, and in such a way that a tape engages the pen and this tape by means of electrostatic Force is coupled to a constantly rotating shaft. The forward movement occurs when coupling, during the backward movement of the pen when uncoupling by means of a return spring is effected. In this arrangement, too, is a

409 690/70

Even impression is not guaranteed, as it will generally not be possible for the individual Press the pens against the writing pad with the same force, as this depends heavily on the coupling effect depends, however, in the case of the individual couplings due to the nature of the surface can be very different.

The subject of the invention is a line printer in which the individual characters are constructed like a mosaic from an m · «-dot grid and the lines are printed line by line, with a number of printing elements corresponding to the number of print points along a line line, which are formed as angle levers made of thin sheet metal formed with a nose causing the imprint and are jointly driven for the imprint by an electromagnet extending over the entire line width and with an electrically operated holding device for each pressure element, which, depending on its state of excitation, prevents or allows the imprint of the pressure element assigned to it. According to the invention, the angle levers serving as pressure elements are designed as armatures of the electromagnets driving them, the pivot point of the angle levers being outside the magnet, and the holding devices being designed as electrostatic brakes.

The force applied by friction that is produced in electrostatic clutches is in itself known. The generation of the electrostatic force can therefore be carried out in any known manner will. The resetting of the pressure elements can be done with a mechanical spring; more expedient is, however, a magnetic return, in such a way that the bell crank from a second common magnet can be withdrawn into the starting position after the impression.

The invention is illustrated below with reference to FIGS. 1 to 4, for example, explained in more detail. It shows F i g. 1 shows a single printing element with an electrostatic device according to the invention in FIG Side view,

Fig. 2 the section AA,
F i g. 3 the section BB,

F i g. 4 shows another embodiment of the pressure element according to the invention.

In the figures, the cross-sections are not shown to scale, but in the line to the line parallel dimension is extremely strongly distorted in order to show the details clearly.

It is assumed that there are five printing elements for each character and two for each space Elements are required so that a total of seven times as many printing elements are required as characters can be written on the line. The individual printing elements 1 are around one for all elements common axis 2 rotatably arranged. On the top right side is one to one Pressure point formed nose 3, which with a corresponding movement of the pressure element on the ribbon 4 beats. The lower part of all pressure elements protrudes into a space that is formed by two of the Line length corresponding magnets 5 and 6 is formed. These magnets are in the usual Made from two pole shoe rails with wound cores in between. The magnet 6 is the return magnet, d. H. the magnetic spring that pulls all pressure elements back to the rest position.

The magnet 5 works as a pressure magnet, which brings all pressure elements to the stop in the printing plane tries. The pressure elements are made stronger in their lower part 7 than in their upper part Part 8. The part 8 is easily movable in a gap that is formed by two insulating foils 9. the two insulating films 9 are in turn surrounded by two electrically conductive films 10, on each of which another insulating film 11 follows. The foils 10 can also be used as metallic coverings of the foils 9 be trained. Between the two foils 9 is located in the space that is not from the pressure element 8 is taken, a thicker sheet metal 12, which is equipped with a soldering lug 13. the Soldering tails of successive sheets 12 are, as in FIG. 1 shows staggered. The metallic foils 10 or the corresponding assignments are through slots in the foils 9 and possibly corresponding Warts or the like of the connecting plate 12

ao conductively connected to this. The foil packets belonging to the pressure element 7, 8 are through Intermediate pieces 14 separated from one another and lined up with these isolated on the axis 15, 16. These The main purpose of the axis is to center the

the whole block. The actual assembly will caused by the axes 17 and the spacer pieces 18.

The new line printer works with continuous paper transport as follows:

A ratchet wheel (not shown) that alternates between the magnets is coupled to the transport axle 5 and 6 switches on. By attracting the magnet 5, all pressure elements are against the Pressure surface is thrown and create a mosaic point there, if not involved in this movement can be prevented by the electrostatic friction between the foils. During the reset time, which is effected by the magnet 6, the metallic foils or coverings 10 over the solder connections 13 first discharged and then charged individually. Leave the uncharged slide sets the movement of the pressure element 7, 8 to unhindered. The charged sets of foils prevent this Movement due to the friction occurring between the foils and the pressure element 7 as a result of the electrostatic force. The pressure elements themselves are always on the common axis 2 Earth potential.

Fig. 4 shows another possible embodiment for a pressure element, in which the pressure elements have less inertia than the printer described. This is beneficial when speeding up the print is great.

In principle, however, this pressure element or its actuation does not differ from the one above described. Here, too, the individual pressure elements 1 are around the common axis 2 pivotable. Only the arrangement of the two electromagnets is different, namely as follows: that the part 8 of the pressure elements performs a lateral movement in the direction of the double arrow 19. The path of the pressure elements is therefore not as great as in the exemplary embodiment in FIG. 1 to 3, in which the printing elements are pulled forward out of the foil package.

The electrostatic separation in the second example is similar to the first and does not require one further explanation.

The particular advantage of the new printer over the known printers is that mechanical spreading of components is avoided. This is possible through the application electrostatic forces, which in turn has the advantage that the friction-generating forces are only for a braking action can be used so that wear of the rubbing surface is minimized is limited.

The basic representation in the figures can be further developed from a technological point of view. So it may be useful to make the electrostatic braking device from simple stamped parts build up, which is covered in the appropriate places by a highly insulating and friction-resistant varnish are. The pressure element 7, 8 can also consist of a relatively thin central sheet and two for reinforcement of the part 8 glued-on side panels be constructed.

Claims (3)

20 patent claims: 1. Line printer, in which the individual characters are built up like a mosaic from a m · n dot grid and the lines are printed line by line, with a number of printing elements corresponding to the number of print points along a line line, which are formed as angled lever formed from thin sheet metal with one of the Imprint causing nose formed and are jointly driven for the imprint by an electromagnet extending over the entire line width and with an electrically operated holding device for each pressure element, which, depending on its state of excitation, prevents or allows the imprint of the pressure element assigned to it, characterized in that the as Angle lever (7, S) serving pressure elements are designed as an armature of the electromagnet (5) driving them, the pivot point (2) of the angle lever being outside the magnet, and that the holding devices are designed as electrostatic brakes. 2. Line printer according to claim 1, characterized in that the electrostatic brake made of arranged on both sides of each angle lever and located between two insulating foils conductive foils. 3. Line printer according to claim 1 and 2, characterized in that as a return spring for the angle lever (7, 8) an electromagnet (6) is used. Considered publications:
British Patent Nos. 786 027, 824 208. 1 sheet of drawings 409 690/70 9.64 © Bundesdruckerei Berlin