DE1056848B - Recording and / or playback magnetic head for magnetic recorders and process for its manufacture - Google Patents

Description

The invention relates to the manufacture of recording and / or playback heads for magnetic sound recorders. The various requirements in the manufacture of such heads would be in education a mechanically exact gap of exactly the same width, the simplest and cheapest possible manufacture the heads and the avoidance of rejects. The problem of the formation of a mechanically exact Head gap has therefore become more and more important and difficult, because it is for reasons of economy of the recording medium, there were repeated decreases in the recording medium speed a substantial reduction in the head gap width to values of about 0.004 to 0.007 mm made necessary in order to absorb the higher audible frequencies as much as possible and to be able to reproduce.

It is known in the manufacture of magnetic heads to have one or more forming the magnetic head Pressing sheet metal parts against each other with the interposition of the split foil by means of a clamping device and to brace in this position. Such magnetic heads with a clamping device, however, have because of their misshapeness and the possibility of subsequent relaxation, in which the gap width changes in of the order of magnitude of 0.001 mm have a disruptive effect, is of no importance in practice.

In another known magnetic head, a non-magnetic spacer with two highly permeable Pole pieces and high-frequency iron mass pressed to form a magnetic head. In doing so, neither the required Achieve dimensional accuracy with the one that must be adhered to precisely over a long period of operation Head gap width remains unchanged, nor the high manufacturing quality, which the manufacture of magnetic heads ensures maximum dimensional accuracy with the lowest possible number of rejects.

Furthermore, a method for manufacturing magnetic heads for magnetic sound devices is known in which the head gap through the joint of two composite joints containing an interposed film Angle is formed from highly permeable sheet metal, which initially consists of one piece of highly permeable Sheet metal is clamped folded with the interposition of the split film, the free end pieces are bent at an angle, then a mutual mechanical fixing of the free ends by soldering and then dividing the sheet metal piece in two by separating the folded piece, preferably except for a remnant. This manufacturing process has proven to be suitable for mass production the magnetic heads in question have been found to be too complicated and therefore too expensive. It is also known massive, d. H. not laminated (not peeled) pole

Recording and / or playback

magnetic head for magnetic sound devices

and its method of manufacture

Applicant:

Max Grundig,
Fürth (Bay.), Kurgartenstrasse 37

Dr. Ernst Christian, Nuremberg,
has been named as the inventor

or to fasten core parts in the recess of a head plate. However, this is not the difficulty to overcome that exist with regard to the formation of secondary gaps in laminated poles.

In contrast, the invention relates to a magnetic recording and / or reproducing head for magnetic sound devices, whose peeled pole pieces, separated by a non-magnetic gap foil, form the parallel gap fill in a non-magnetic head plate and be held together by this head plate, in which the disadvantages of the aforementioned heads and their manufacturing processes are avoided in that In accordance with the invention, the fixed connection of the pole shoe with the recessed head plate is produced in this way by compressing the parallel gap in the head plate is that it lies against the ParaMel gap Peeled pole shoe material with growing towards the lateral ends of the head plate parallel gap Pressure is permanently deformed. In this way, the production is significantly cheaper of the heads in question achieved, which still have the advantage that even with longer Lifetime of the heads maximum dimensional accuracy of the gap is also guaranteed at its ends, because the possible spreading of the pole pieces at the ends of the head gap which takes place during manufacture Counteracts permanent deformation of the head plate in the area of the head gap ends with increased pressure.

Several exemplary embodiments of the invention are described below with reference to FIGS. 1 to 3. These figures essentially show the view of the z. B. made of brass head plate

909 509/208

Gap magnetic head, through the recess of which the pole pieces are separated by a non-magnetic gap foil protrude. The pole pieces are acted on one or both sides on the outer edges of the head plate Pressure of a stamp permanently mechanically deformed and so the head plate firmly with the pole pieces tied together. By grinding, one is created for the recording medium (magnetic tape) to pass by. suitable area created. In the manufacturing forms described with reference to FIG the connection of the top plate with the pole pieces takes place through the laterally adjacent pole pieces Pressing in. Fig. 3 shows a cross section through the head plate and the pole pieces.

In the first form of manufacture of a magnetic head of the proposed type shown in FIG the top plate 1 with a rectangular parallelepiped 2 and parallel to the parallel gap edges 6 provided head plate edges 7 used. To even during a long service life of the magnetic head the spreading apart of the pole piece sheets separated by the non-magnetic gap foil 3 to prevent at the gap ends, one or both sides after the introduction of the pole pieces 4 in the Parallel gap 2 brought the plunger 5, which is concave in the direction of the edge, to act in the case of the head plate material lying against the gap with the ends of the head plate parallel gap 2 causes the permanent deformation 8 to increase in pressure (shown in dashed lines). Possibly can reduce the pressure by inserting elastic foils between the plate material and the pole pieces be mitigated.

In the second embodiment, explained with reference to FIG. 2, the head plate 1 becomes convex molded window 9 and the flat stamp plate 10 is used. Here, too, occurs with the one or both sides Pressing the head plate material lying against the window 9 is indicated by dashed lines Permanent deformation 8, in which first the stamp plate 10 against the ends of the window 9 with increasing pressure acts on the window 9. This pressure, which increases towards the ends of the window 9 remains effective for the duration of the deformation, whereby the spreading of the pole pieces to the Head gap ends is prevented and the most precise dimensional accuracy of the magnetic head gap with its advantages is preserved in the long run.

The desired pressure distribution can also be achieved by pressing in the middle head plate part - adjacent to the head plate gap or window - according to FIG. 3 from above on one side, from above on both sides, from above and below on one side or from above and below on both sides or in any combination . In the case of a head plate with a parallel gap, at least one plunger with a concave shaped pressure plate (see Fig. 1, reference number 5) and, in the case of a head plate with a gap with gap edges running convexly against one another (see Fig. 2, reference number 9), at least one printing 6 ^ stamp with flat stamp plate (see Fig. 2, reference

character, 10) is used. The indentations are denoted by 11.

Claims (5)

Patent claims: 1. Recording and / or playback magnetic head for magnetic sound equipment, whose by a non-magnetic Peeled pole pieces separated from the gap foil form the parallel gap of a non-magnetic top plate fill in and be held together by this head plate, characterized in that the Fixed connection of the pole shoes (4) with the recessed head plate (1) by pressing together of the head plate parallel gap (2) is made in such a way that the one lying against the parallel gap (2) peeled pole shoe material with against the lateral ends of the head plate parallel gap (2) increasing pressure is permanently deformed. 2. A method for producing magnetic heads according to claim 1, characterized by the use a head plate (1) with a parallel gap (2) and parallel to the parallel gap edges Top plate edges (7) on one or both sides after inserting the through the split film separate pole shoes in the parallel gap (2) a plunger that is concave in the direction of the edge (5) acts (Fig. 1). 3. A method for producing magnetic heads according to claim 1, characterized by the use of a head plate (1) with a parallel gap (2) with gap edges (6) which are convex to the parallel outer edges of the head plate, on one or both sides after the introduction of the Pole shoes (4) separated by the split film act in the window (9) by a stamp plate (10) which is flat in the direction of the edge (FIG. 2). 4. A method for producing magnetic heads according to claim 1, characterized by the use a head plate (1) provided with a parallel gap (2) on which, after the insertion of the through the split foil separated pole shoes (4) in the parallel gap (2) on one side, on both sides, from above or below or in any combined manner adjacent to the parallel gap (2) and the top plate (1) pressing in at least one concave shaped plunger (5) in the direction of the gap edge acts (Fig. 3). 5. A method for producing magnetic heads according to claim 1, characterized by the use a head plate with a window (9) with gap edges that are convex towards each other and towards each other a flat plate of the at least one stamp plate (10), which after the introduction of the Pole shoes (4) separated by the gap foil into the gap on one side, on both sides, from above or below or in any combined manner adjacent to the window (9) and in the window direction the head plate (1) acts in a press-in manner (Fig. 3). Considered publications:
U.S. Patent No. 2,469,444;
French patent specification No. 1 121 583. 1 sheet of drawings 4.59