DE8005330U1 - Device for heat dissipation from dot matrix print heads - Google Patents

Description

, · ': "-TRIiJM ^ H, WERKE * f

Stock company
Further Strasse 212, 8500 Nuremberg

EP / Sp / Oz / 2116 Feb. 20, 1980 Device for heat dissipation from dot matrix print heads

The innovation relates to a device for removing heat from the Electromagnets actuating print wires in wire dot print heads.

A quick and reliable discharge of the in the electromagnet Heat loss caused by a dot matrix print head is an important factor for the maximum achievable printing speed. They are different Devices have become known which aim to improve heat dissipation. One sees z. B. before, the coils of the Electromagnet with a band of thin copper wires in thermal contact to bring and dissipate the heat to a cooling plate via this. In another, the electromagnets point for better heat dissipation Cooling fins on. However, these devices are inadequate or unsafe in their mode of operation. The innovation is therefore based on the task to create a device that makes it possible to quickly reduce the heat loss occurring in the electromagnets and safely vented to the air surrounding the printhead.

The object is achieved by the features in the characterizing part of the Protection claim 1. The features of the subclaims is a further improvement of the intended effect achieved.

The advantage of the innovation is that it is safe and easy to use rapid dissipation of heat from the printhead to the surrounding air and thus a higher maximum printing speed is achieved.

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The details are shown on the basis of one in the drawings
Embodiment explained in more detail. Show it:

Fig. 1 is a front view, Fig. 2 is a rear view, and FIG. 3 shows a section A-B of the device according to FIG. 1

As can be seen from the drawings, FIGS. 1, 2 and 3, the electromagnets 1 are arranged essentially in a circle and with their yokes i

6 in openings 7 of a likewise circular plate 4 by means of § glued in with a thermally conductive adhesive. Perpendicular to this plate I.

4, an outer molded ring 2 and an inner molded ring 3 are arranged, | between which the electromagnets 1 are located. The spaces |

between the electromagnet 1, the outer molded ring 2, the inner molded ring 3 and the plate 4 are filled with a potting compound 5 whose thermal conductivity is considerably better than that of air. The | outer ring 2 and plate 4 are expediently made of light metal for reasons of thermal conductivity and weight reasons, ζ. B. aluminum, the inner mold ring 3 because of the low
Weight made of plastic. Furthermore, the metal parts are, so
outer molded ring 2 and plate 4, to improve heat absorption
or heat radiation blackened inside and outside.

Is now created by energizing the winding in the electromagnet 1
Heat loss, this is given off directly to the casting compound 5.

-5 •• '•••••• 4 /,

ben, which they, due to the good thermal conductivity, quickly in Direction of the temperature gradient, that is, in the direction of the outer molded ring 2 or plate 4. The heat loss is supported by these by the blackening, absorbed and, also supported by the blackening, by the relative to the surface of the electromagnet large surface from the outer ring 2 and the plate 4 radiated to the environment.

In contrast to the exemplary embodiment, it is possible to use the outer molded ring 2 and / or to blacken the plate 4 only on one side, since this is sufficient for many applications. Furthermore, the outer molded ring 2 and the plate 4 made in one piece as a cup-shaped part will.

The advantage of the innovation described above is that that a quick and safe dissipation of the in the electromagnet one The resulting heat loss is made possible by the dot matrix print head. As a result, despite a slight increase in the weight of the print head, due to Form rings and potting compound, a significantly higher maximum printing speed can be achieved. Further advantages can be seen in the fact that the derivation the heat loss is carried out with relatively simple means, and that, despite the increased printing speed, no particularly heat-resistant Materials must be used.

In order to lead the connecting wires of the magnets 1 out of the housing it is useful to provide a hole 8 in the plate 4 in the area the recess 9 of the inner mold ring 3 is located. The connecting wires are thus cast into the casting compound 5.

Claims (5)

nt β λ a * re ca μ «* a · ι Aktiengesellschaft Further Strasse 212, 8500 Nuremberg EP / Sp / 0z /? i \ o Feb. 20, 1980 Claims for protection 1. Device for dissipating heat from those actuating the print wires Electromagnets for needle print heads, marked d / a d υ r c h, that the substantially circularly arranged electromagnet (1) between two concentric Form rings (2, 3) are located vertically on a plate (4), the shape of which corresponds to that of the outer form ring (2), stand and that the spaces between the electromagnets (1), the inner molded ring (3), which is preferably made of plastic, the outer molded ring (2), which is preferably made of light metal, and the plate (4), which is preferably made of light metal a potting compound (5) are filled, the thermal conductivity of which is considerably greater than that of the air. 2. Device according to claim 1, characterized in that that the electromagnet (1) with its yoke (6) by means of an adhesive that conducts heat well in openings (7) of the Plate (4) are glued in place. \ 3. Apparatus according to claim 1, characterized in that the electromagnet (1) with its yoke (6) in the openings (7) of the plate (4) are pressed. III I 4. Apparatus according to claim 1, characterized in that that the outer molded ring (2) is blackened. 5. Apparatus according to claim 1, characterized e t that the plate (4) is blackened.