DE7024223U - Mosaic print head - Google Patents

Description

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WALTHER-BÜROMASCHINEN GMBH

7342 GERSTETTEN / WÜRTT. June 23, 1970

MOSAIC PRINT HEAD

The innovation relates to a mosaic print head with

I.
in particular printing needles guided therein, the

Image grid usually represented by a 5x7 grid and the pixels are generated by printing wires.

So far, these guides of the Dru: .üiaaeln were executed point by point with drilled sheets arranged one behind the other. It turned this disadvantageous out ΐ · that by the deviation of the needle form of the Ruhelage-

shape, due to the sideways swing within

and between the guide bores, the path of the drive

: lateral end of the print wires larger than the path of the

[. Printing end of the needles is. This inevitably resulted

The process contributed significantly to the deterioration of the

Printing process at.

Attempts have already been made to remedy this inconvenience by placing the printing pins in a closed plastic block to be arranged and for each print needle a separate guide

provide a hole or through a slightly curved capillary tube receiving the needle in order to cover it all over Length up to the exit against any bending phenomena to protect.

This type of arrangement did not lead to a satisfactory result either. Practice showed that still significant frictional and locking forces occurred due to the relatively longer pressure wires used, as well as above In addition, a manufacturing process suitable for series production of the print head adversely affected the same, so that the higher printing speed to be aimed for could not be reached.

The task and the purpose of the innovation is now seen in avoiding the aforementioned disadvantages to a large extent and creating one To propose mosaic print head, the significantly higher printing speeds while avoiding any friction losses and allows bending stresses through the use of shorter printing wires in the printhead as well as the most favorable mass production possibilities guaranteed.

This is achieved in that a consisting of two individual housing parts, made of known plastic, casting

Resin or zinc injection molded body block that can be assembled into a unit is provided, wherein the guide channels for the printing needles with a constant radius of curvature on the stair-like Surface of the base body are incorporated.

Furthermore, the innovation is that the printing wires are pre-bent with the same constant radius of curvature are, so that this embodiment obviously has the advantage that frictional forces due to bending stresses and Loss of wear and tear in the ducts is reliably avoided will. Only this proposed innovation enables the strong curvature of the channel guides in the base body in an advantageous manner Way, by these guides can be kept relatively short, since they are on a shorter radius arc for the Print needle drives allow the necessary expansion with relatively small body block dimensions and thus the mass can be kept small for the moving functional parts of the known print needle drive. In this way it is ensured that significantly higher printing speeds can be achieved compared to the known types of construction can.

Further details and advantages of the innovation emerge from the following description of the exemplary embodiment Referring to FIGS. 1 to 3, the parts that are the same in the individual figures also have the same reference numbers.

Show it:

Figure 1 is a schematic top view of the two-part mosaic print head with guide channels built into the surface of the base body in a step-like manner with embedded printing pins and schematically shown electrodynamic printing pin drive,

FIG. 2 shows a partial section through the two-part mosaic print head in the direction of the arrow along the line A-A of FIG in an enlarged view,

FIG. 3 is a schematic view in the direction of arrow B of FIG Figure 1 of the image grid in, for example, 5x7 pixel printing needle positions.

According to Figures 1 and 2 is opposite to the known per se made of a plastic or cast resin material housing block this made of 2 housing halves, namely the basic

body 1 and the cover body 2. The base body advantageously has 3 step-like surfaces on its surface Paragraphs 4, on which upwardly extending, a constant radius of curvature 5 forming guide channels 6 incorporated are. The pre-bent printing pins, which also have the same constant radius, are inserted into these guide channels 7 are introduced and are safe in this way up to the exit from the mouthpiece 8 up to the stop on the printing plane 9 Gegep frictional forces and bending stresses are guided in a sliding manner. The same step-like stepped surface 10 aufweiserde The cover body 2 can be connected to the base body 1 by means of a conventional or other type of fastening (not shown).

This Ausführuiigsform the print head, especially in connection to the proposed relatively short RadiusLrümmungen the guide channels simultaneously with the print wires he _fe it significant advantages by the channel guides as well as the run in this way print wires can be kept very short, because these short arcs for Electrodynamic drives result in the necessary spreading angle, allow a space-saving small print head circumference and thus the mass for the moving functional parts can be kept extremely low. All of these advantages in turn make a not insignificant contribution to the increased printing speed.

In FIG. 3, for example, the image locking is indicated by a 5x7 grid shown. But it is also straightforward possible., with serial notation di lines in several Steps to take imprint, so you can click on this Way can also get by with 7 pressure needles.

- Protection claims -

Claims (2)

Protection claims 1. Mosaic print head with, in particular, printing needles guided therein, the image raster usually being represented by a 5x7 grid and the pixels being generated by printing needles, characterized in that one of two individual housing parts (1, 2) consisting of known plastic, cast resin or zinc injection molding material is provided, which can be joined together to form a unit, the guide channels) 6) for the pressure needles (7) having a constant radius of curvature (5) incorporated into the step-like surface (3) of the base body (1) and the pressure needles with the same constant RadJus (5) are pre-bent and slidingly embedded in the guide channels. 2. Mosaic print head according to claim 1, characterized in that the bearing surfaces (10) of the cover body (2) have the same stair-like paragraphs (4) as the base body (1) and these simultaneously serve as a guide and cover for the printing needles (7).