DE1926911U - SOUND HEAD FOR MAGNETIC SOUND DEVICE. - Google Patents

Description

PATENTANWÄLTE '/' C

DlPL-ING. CURT WALLAcfiAi 4FJI DIPL-ING. GÜNTHER KOCH

DR.TINO HAIBACH -

8 MUNICH 2, September 1st, 1965

• OUR MARK: 5889 ~

KEBRLE & MOSER, laboratory for miniature components, Daohau / Bavaria

Sound head for magnetic recorders

The innovation affects sound heads for magnetic recorders? In particular, it relates to audio heads for multi-track recording, and can also be used with advantage in audio heads with mono recording. ^:

Such heads have a magnetic circuit for each track with an air gap forming magnet system. Bach a well-known In design, the magnet system has a core consisting of lamellar sheets stacked horizontally on top of one another, both of which Legs at their, front end, the pole pieces with the between they carry provided microscopically narrow air gap and are connected at their rear end by a yoke} the core has one or more windings! Core and air gap together form a closed magnetic circuit «From the area Apart from the pole pieces, the magnetic core is preferably used to achieve a uniform magnetic flux with uniform Cross-section formed. The amount of the magnetic

The core is essentially given by the "track width".

With regard to the mechanical structure of the laminated core as well as with regard to the attachment of the winding or windings Various designs are known: For example, the magnetic core can be composed of two or three cables; either one winding, preferably on the yoke connecting the legs to one another, or two windings be provided on the two magnet legs.

There are both considerations for the construction of such tape heads constructive-structural type as well as electrical type decisive:

On the one hand, structurally ever smaller dimensions and in particular a low overall height for the sound head and thus for aimed at the magnet systems; This requirement is particularly in the course of the newer device construction with stereophonic or Multi-track recording has become acute as it involves two or more Systems on a narrow, through the 'track spacing on the .Magnetto carrier given space must be accommodated one above the other, whereby the one system does not affect the system above target.

On the other hand, despite this transition to ever lower Dimensions at the same time made high demands on the magnetic and electrical properties, in particular a high voltage output can be achieved, for which a sufficient

Inductance (and thus number of turns of the winding) of the system is required.

From the above considerations it follows that the accommodation the number of turns required to achieve sufficient inductance while maintaining at the same time The lowest possible overall height is of considerable practical importance. In addition to these, the mode of action and the best Immune purpose of such sound head arrangements resulting demands The arrangements should also be simple and with great accuracy in terms of production technology, despite the small dimensions as well as can be produced with the same »lasting properties being.

A tape head arrangement is already known in which the the winding with bobbin carrying yoke to gain winding space with the lowest possible overall height with opposite the legs of reduced height is formed.

However, this known design has a number of disadvantages.

By having the core opposite in the area carrying the winding to the. Is formed legs of reduced height, there would be a discontinuity in the cross-sectional area along the magnetic circuit. This is for "the well-known reasons for the electro-magnetic behavior of such an arrangement

unfavorable and therefore undesirable. "

In addition, the known design also has the following other significant disadvantages in terms of manufacturing technology and efficiency. In the known embodiment, the core is made up of only ΣΧ zv / ei symmetrical ropes, so that a yoke half is attached in one piece to each of the two legs on the 'rear' side, these yoke halves come to rest with their end faces during assembly . In order to achieve a sufficiently low magnetic contact resistance at this joint, careful machining of both abutting end faces of the leg halves (lapping) is necessary. At the same time, care must be taken during manufacture that the length of the yoke halves is precisely adhered to within the narrowest tolerances and that the end faces of the yoke halves are exactly parallel to each other and at right angles to the longitudinal axis of the yoke. If these conditions are not guaranteed within the narrowest tolerances, the result is. Assembly of the two symmetrical halves thin gaps at the joint between the two yoke halves, which makes the head unit unusable. '■'. ■■■ / ■ - · '· _t ^

From this serious disadvantage, both exist known execution still the risk that-despite extreme smooth machining Dirt or dust particles on the end faces during assembly between the abutting 'end faces of the "two

Get yoke halves; this would have the consequence that the two yoke

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Then they didn’t help each other very well. get in touch

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and a gap, however narrow, remains between them, whereby the magnetic resistance increases quite significantly and affects the functioning of the entire unit.

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■. - - ■■ .. * The innovation thus relates to a sound head for a magnetic recorder, in particular

. *** ■ - ": ''*" * special for multi-track recording / with a horizontally laminated core that conducts the magnetic flux and whose height is essentially determined by the width of the track Connecting core. Yoke is arranged and the yoke carrying the winding is designed with a reduced height compared to the magnetic legs . A sound head arrangement of this type is to be created by means of the control system, in which the described disadvantageous parts of the known design are reliably avoided.

For this purpose it is provided according to the alloy that the Yoke carrying the winding with an enlarged

of the width, so that the Joeh is essentially has the same cross-section as the legs, and that the magnet legs have slot-like openings in the region of their rear ends have, which in width and height ent the dimensions of the yoke speak and in which the yoke is "set".

The widened design of the yoke provided according to the control, through which, despite the height reduction, essentially the Maintain the same core cross-section as in the area of the legs remains a uniform flux density in which the "legs and ensures the yoke encompassing part of the core.

The three-part execution of the keriis according to the innovation, according to which the yoke, designed as an independent part, is inserted into corresponding slots at the rear ends of the “legs” is, provides compared to the known two-part design essential manufacturing technology. and effective benefits. The transition between the legs and the yoke which is designed as an independent part and can be inserted into the leg ends takes place in a substantial part parallel to the lamellar plane and not at a butt joint running transversely to this. Through this there is no need for special processing of the yoke lamellas or the "leg lamellas" at the connection point; even if scattered dust or dirt particles between the Ropes connected to one another by inserting should arrive, because of the resilience of the thin slats in the case of the usual provided compression pressure ensures sufficient contact between the large-area adjacent lamellae guaranteed by the yoke and legs.

The design according to the innovation also has the following significant advantage: In the three-part design provided according to the innovation, "the yoke m ± f ^; the coil body carrying the winding is inserted at the rear end of the two shackles after the two shackles have been assembled. It is therefore" possible vqrzufertigen head units with the two legs in large numbers and to take in stock and final use yokes with the desired '. i windings depending on denjsich changing demands This represents a significant herstellungsteehnischen and commercial advantage over the known embodiment is wherein the.

Bobbin with the winding "when assembling the legs must be placed on the yoke and cannot be exchanged afterwards.

According to a particularly advantageous embodiment of the hiring it is provided that the legs are made of shorter inner and outer, longer lamellar plates protruding on both sides are layered in such a way that the slot openings remain between the protruding longer lamellas, in which the Yoke is inserted.

This last-mentioned embodiment of the innovation also has the special advantage that by widening the Yoke plates increase the transition area between the yoke and magnet legs with the same cross-section of the yoke and thus the magnetic one Resistance of the core is reduced; Magnetic field densification at the transition point between yoke and magnet leg are thereby avoided.

In the last-mentioned particularly advantageous embodiment. the innovation with in Schiitζöffnungen the rear ends the leg inserted yoke still has the option of either symmetrical or asymmetrical with respect to the yoke the height to be inserted into the legs. In the case of two-track systems with two magnet systems arranged one above the other, the asymmetrical Arrangement of the yokes in the relevant magnet systems has the advantage that the winding space remaining between the yokes compared to the case where the yokes are in the middle

The amount of the "magnetic core in question" is used, increased will.

Further advantages and details, the! Inflation arise from the following description of examples based on the drawing; in this show.

! • ig. 1 shows a single magnet system according to an embodiment of hiring without holding or housing parts | in fact · .

1a shows a plan view of the magnet system, ■

Fig. 1b is a long sectional view of the line b-b in FIG 1a,

Fig. 1c is a side view of the magnet system.

The Figg. 2 and 3 each have a tape head unit with two magnet systems arranged one above the other in accordance with the rate of increase for multiple recording, whereby in the embodiment according to FIG. 2 the yokes are inserted symmetrically, in the embodiment according to FIG.

In FIG. 1, a magnet system according to the firing is shown. The magnetic core of the system consists of .j ^ white · legs 1, the at their front ends in the form of buttocks J'-with between this remaining air gap 4 formed ■ - are ,, as well as from one connecting the legs to one another at their rear end Yoke 2. As can be seen in particular from Figure 1c,

is the magnetic core, both the magnetic legs 1 as also the yoke 2 composed of horizontally stacked laminations. From the side view in Figure 1c it can be seen that the legs 1 from an im. Inner layers of short lamellae 5 and lying on both sides longer lamellas 6 exist, which protrude to the rear on both sides beyond the stratification of the short lamellas 5, so that a Schiitζöffung formed with the height h and the width b is, in which the horizontally laminated yoke 2 fits and is used during assembly. From Figure 1b it can be seen how the lamellar layering 2 of the yoke protrudes between the yoke in the area of the overlap of the leg and the joQh long slats 6 of the legs is used.

The yoke 2 carries the winding 7. As can be seen from FIGS. 1b and 1c, the yoke is provided with an opposite (essentially height H of the rest of the magnet core or of the legs is formed with a reduced height h, determined by the track width, in such a way that - assuming a predetermined overall height G - a gain in winding height (essentially correspondingly the difference H - h) is achieved or - assuming a predetermined winding height - a lower overall height is achieved will.

As can be seen in particular from FIGS. 1a and 1c, the yoke has a width compared to the width of the rest of the magnet core and in particular the magnet leg enlarged width b from

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formed so that the yoke has essentially the same cross-section as the legs despite its lower height h and thus an essentially uniform cross-section for the entire magnetic core (except for the pore area) is ensured. It can also be seen that the widening of the yoke significantly increases the transition area between the yoke 2 and the legs 1 and thus reduces the magnetic resistance of the core : Magnetic field interference at the transition points mentioned is therefore largely avoided.

As already mentioned, the construction of a magnet system according to the M ^ tai ^ g already results in son heads for mono-track recording a significant advantage, either by being that of a given Total height available changing room, enlarged or with a given height to be accommodated, the overall height is reduced. That is particularly advantageous M & tlMSfg, however, with! Sound heads with several magnet systems for Stereo or multitrack recording applicable. Implementation examples these are shown in FIGS. 2 and 3.

FIG. 2 shows two magnet systems of the type described in FIG Sorted one above the other in one. Tonkopf, for example for stereo 1/4 track. With 10 is a (in Figure 1 not shown) bracket or housing part. {for example made of brass) indicated? between the two systems

a core sheet 11 is provided as a shield, the between the space available to the two systems is reduced, but to avoid mutual interference of the two systems is required.

The gain in winding height achieved through the design of the systems according to the innovation is in multi-lane systems of this type especially important because here the one between the two magnet systems available space, through the specified track spacing on the. Sound carrier is fixed and not arbitrary can be expanded. The following numerical example serves to illustrate the relationships that exist in practice (It should be noted that Figures 2 and 5 are not true to scale are): The distance between the two tracks from center to center is, for example, approx. 3.5 mm (distance a in Figure 2) | the height of the surface (and thus the height of the magnetic core) is, for example, 1 mm .; thus remains a space of 2.5 mm between the two magnetic cores (distance b in FIG. 2); about 0.2 mm for the shielding plate 11 from this (Route c in Fig. 2); thus remain between the shielding plate and the respective magnet system, approx. 1.1 mm; minus approx. 0.2 mm for the bobbin and about 0.2 mm. for the ceiling insulation in the case of training according to the state of the art (yoke in the same Ji Height like legs) only about 0.6 mm actual winding height remain.

By training according to the "fire," at which the altitude of the yoke 2 is much lower than the height of the legs 1;

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the available winding height is almost twice as high increased.

In Figure 2, the yoke of ^are: two magnetic systems as the amount used in the illustrated embodiments in Figure 1 symmetrically with respect to the magnet leg. A further gain in winding height between two such magnet systems of a double-track head can be achieved if the height of the two systems is used asymmetrically, as shown in FIG. The yoke 2 'of the upper magnet system is opposite the middle

line of the upper magnetic core shifted upwards, while the Yoke 2 "of the lower system opposite the center line of the associated Magnet core is offset downwards ". This increases the available winding space again considerably; however, an increased overall height is associated with this embodiment.

The innovation is not limited to the exemplary embodiments described. For example, it can also be used in the case of a design in which two windings are arranged on the legs of the magnet core, whereby, for example, the required number of turns can be accommodated on a shorter leg length. _:

• A

Protection claims :

Claims (4)

PJU73216HL8.S5 Protection claims; 1. Sound head for magnetic recorder, especially for multi-track recording, with a horizontally laminated core that conducts the magnetic flux, the height of which is essentially is predetermined by the track width, in which the winding on the yoke connecting the legs of the core is arranged and the winding supporting yoke is formed with a reduced height compared to the magnet legs is, characterized in that the winding (7) supporting yoke (2) with opposite the Magnetic legs (1) of enlarged width (b) is formed such that the yoke is essentially the same Cross-section like the legs, and that the magnet legs (1) in the. Slit-like area of their rear ends Have openings (h, b, Fig. 1e) which correspond in width and height to the dimensions of the yoke (2) and in which the yoke is inserted. 2. Sound head according to claim 1, characterized in that that the legs (1) from inner shorter ones (5, Figure 1c) and outer, longer (6) lamellar plates protruding on both sides are layered in such a way that between the protruding longer lamellas remain the slot openings into which the yoke is inserted. / r 3. Sound head according to claim 1 or 2, characterized net that the yoke (2)] with respect to the height symmetrically in the Leg is used (Figures 1, 2). 4. Sound head according to claim 1 or 2, characterized in that that when applied to a ZVeispursystem the yokes (2 ', 2 ", Figure 3) of the two superimposed magnet systems are inserted asymmetrically with respect to the height in the associated cores.