DE7509172U - PRINT HEAD FOR A POINT PRINTER WITH A GUIDE DEVICE FOR THE PRINT NEEDLES - Google Patents

Description

Print head for a dot matrix printer with a guide device for the printing pins

Print head for a dot matrix printer, consisting of a truncated cone shaped housing, mounted on a rear base plate electromagnetic drive devices for driving the printing wires and a guide device for the in spatial curves running print wires in the area between the rear base plate and a mouthpiece receiving the front ends of the pressure wires.

In a known device for guiding the printing needles (DE-AS 12 49 570) are guide channels for guiding the print needles provided, in addition, the printing wires through transversely

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forces acting on the direction of movement at the corresponding Areas of the walls of the guide channels are created. Such a rigid guide in continuous channels requires high manufacturing costs, especially a relatively large play must be left between the print wires and their guides in order to avoid unnecessarily high frictional forces to avoid. Undoubtedly, by using additional lateral forces, it is possible to achieve an indefinite one Rule out the location of the printing pins, which are also known as writing wires, but this also represents one additional effort.

In another known embodiment (DE-OS 21 19 417) each needle runs in the area between its drive and a guide through a metal wire helix arranged at the front end of the dot matrix print head. In this version it causes difficulties with occasional jerky movements of the needle print head Avoid transverse vibrations of the metal wire coils.

The task of the innovation is to create a print head for a dot matrix printer to create, which is not only through an exact guidance of the print needles in optimally predeterminable guide paths distinguishes »but is also easy to manufacture and into which the printing pins can be threaded without difficulty in the course of manufacture.

According to the innovation it is therefore proposed that the guide device made up of several guide plates with double conicals arranged perpendicular to the housing axis at a distance from one another There is guide bores, the guide bores assigned to a certain th print needle being the spatial Determine the curve shape of this print needle.

The thickness of the guide plates is about 8 to 12-fold psi and their distance to each other about the 10- to 20 times the diameter of the print wires.

The conicity of the threading cone and exit cone double-conical guide bore is different from guide plate to guide plate and on adapted to the desired curve shape of the printing pins.

There are other forms of the innovation in the rest Contradictions laid down.

The innovation creates a needle print head that works with high operational reliability and can be mass-produced, in which all needles are guided in such a way that transverse vibrations which could lead to falsification of the typeface do not occur. In addition, the needles can thereby Thread well that they * automatically in the Einfädelkonus the next guide plate may be used without additional aids, get dyrch the executive board reached to guide plate curvature ji ^ art ¹ ie. In the drawing, an embodiment of the innovation is shown. Show it:

Fig. 1 shows a partial cross-section through a guide plate ,

2 is a plan view of a guide plate for a dot matrix printer with nine printing pins.

3 shows a cross section through the housing of a wire dot print head ,

4 shows the rear view of a print head,

£ Fig. 5 is an enlarged partial representation of three guide

i ^; tion plates and a print needle guided therein.

3 The print head for a dot matrix printer consists, as shown in Fig.

I 3 and 4 illustrate in their entirety, from a ke-

jjj frustum-shaped housing 1, on the rear base plate

I 12 attached electromagnetic propulsion devices 2 for

I drive several printing pins, of which in Fig. 3 the printing

I needle 3 is shown and a guide device.

I The management organization consists of several verticals

I guide arranged at a distance from one another to the housing axis

8 support plates 4, 4a ... 4f with double-conical guide drill

I stanchions 5, 5a ... 5f together, with their spacing a, b ...

I each other about 10 to 20 times the diameter of the

Corresponds to print needles. The thickness s of the guide plates 4,

₅ 4a ... is about 8 to 12 times the diameter of the

ί Print needles.

j Vie Fig. 3 shows, the free end of the print wire 3 is such as \ and the other is only indicated print wires 3 ¹ tightly examples

I each other in the mouthpiece 13.

The details of the training according to the innovation are in

shown on a greatly enlarged scale in FIG. 1, FIG. 1 being seen in conjunction with FIG. The guide plate 4 shown in FIG. 1 and FIG. 2 has double-conical guide bores 5 , each being composed of a single-threading cone 7 and an exit cone 8. The exit cone 8 only has guiding functions and is about 20% larger in height than the threading cone 7 _f which, in addition to the guiding function, also enables threading. There is also a central guide ^{hole 6 for the central print needle 3 1} can be seen, which as a simple one with a thread

Delkonus 9 provided guide hole is formed and has a cylindrical part 14.

In Fig. 1 it can also be seen that 5 thickenings 10, 11 are provided to form the double-conical guide bores. In the remaining area, the guide plate 5 is significantly thinner in order to favorably influence the total weight of the print head.

Claims (6)

· * · Ρ · * a r α r ■ »· | Γ9 ··· ·· ■ · · tr η m · ■ · ■ ··· · · ■ t» e a re · ·> «« t · re claims for protection 1. Print head for a dot matrix printer, consisting of a frustoconical housing, on a rear base plate attached electromagnetic propulsion devices to drive the printing needles made of wire of constant diameter and a guide device for the pressure pins running in three-dimensional curves in the area between the rear base plate and a the mouthpiece receiving the front ends of the pressure needles, characterized in that the guide device of several guide plates (4, 4a ... 4f) arranged at a distance from one another perpendicular to the housing axis double-conical guide bores (5, 5a ... 5f), the guide bores assigned to a specific pressure needle determine the spatial curve of this print needle. 2. Print head according to claim 1, characterized in »that the thickness of the guide plates (4, 4a ... 4f) is approximately that 8-12 times and their distance from one another about 10-20 times corresponds to the diameter of the print wires. 3. Print head according to one of claims 1 and 2, characterized in that that in dar from a threading cone known to calibration (7) and an outlet cone (8) composed Guide hole (5) the height of the outlet cone (8) is greater than the height of the threading cone (7). j; 4. Print head according to one of claims 1 to 3 »characterized in that that with the same conicity of the he »·» · * ■ * ■ * · * ■ ■ m * ^ · a a ο ···· * · r α · threading cone (7) and the exit cone (8) of a guide TDohrung (5) the cone angle (angle of the imaginary cone tip) from the base plate (12) to the mouth piece (13) according to the desired spatial Curve course of the print needles in the range of about 35 ° Ms 20 ° are different. 5. Print head according to one of claims 1 to 4, characterized in that the guide plates (4, 4a ...) have local thickenings (10, 11) in which 3ie double-conical guide holes (5 _f 5a ...) are. 6. Print head according to claim 1, characterized in that the guide plates (4, 4a ... 4f) are made of plastic.