DE1082677B - Four-part ferromagnetic yoke core for the magnetic deflection of cathode rays in cathode ray tubes - Google Patents

Description

GERMAN

The invention relates to a four-part ferromagnetic yoke core for magnetic deflection of cathode rays in cathode ray tubes, e.g. B. for televisions or oscilloscopes, especially for color television purposes.

In cathode ray tubes, e.g. B. Tubes for color television, are around the neck of the tubes Cores made of ferromagnetic materials arranged to deflect the cathode rays inside the tubes. In general, deflections of 70 to 90 degrees are desired. In some cases, however, there are up to 110 °.

The cores are usually made of four parts, each part having a 90 ° sector of the complete toroid so that they are clamped around the magnetizing coil can. For large distractions, the parts must be very precisely fitted and held together.

It is also known to design these yoke cores in such a way that they extend beyond the neck of the cathode ray tubes also extend over part of the actual tube.

A yoke core consisting of four parts, which adapts exactly to the shape of the cathode ray tube and is nevertheless easy to manufacture, is obtained when the yoke core according to the invention consists of a pair of parts each with two ground mating surfaces in the same plane and a second pair of parts with two each there is plane-parallel, ground mating surfaces. The nuclei are now so composed that between the two individual parts of the first pair, the parts of the second pair are inserted, and you through simple longitudinal displacement of the individual parts a good adaptation of the individual parts to the tube shape can reach. This new division of the yoke cores into four individual parts is more advantageous than before known division into four even segments of a circle.

The mating surfaces of all four parts can thus easily on conventional grinding devices to close tolerances be sanded. The parts can be moved sideways against each other without affecting each other the distance between the parts changes, and the parts are lighter than before with the clamping device to get nabbed.

The parts can be made of any ferromagnetic material, such as soft iron or iron alloys. Ceramic products known as ferrites are very satisfactory ferromagnetic materials for the manufacture of the parts. These substances have the general formula χ (MO) · y Fe ₂ O ₃ , in which MO is one or more divalent oxides, χ and y are the molar ratio of MO and Fe ₂ O ₃ , and χ: y is approximately 1: 1 amounts to.

Four-part ferromagnetic yoke core for magnetic deflection

of cathode rays
in cathode ray tubes

Applicant:

Steatite Research Corporation,
Keasbey, NJ (V. St. A.)

Representative: Dr.-Ing. F. Wuesthoff, Dipl.-Ing.G. Pulse

and Dipl.-Chem. Dr. rer. nat. E. Frhr. v. Bad luck man,

Patent Attorneys, Munich 9, Schweigerstr. 2

Claimed priority:
V. St. v. America May 27, 1957

Christopher L. Snyder, Plainfield, NJ (V. St. Α.),
has been named as the inventor

In the drawing there

Figure 1 is a top plan view of the toroidal core assembled from its four parts;

Figure 2 is a cross section taken along line 2-2 of Figure 1;

Fig. 3 is a perspective view explaining how the core is attached to a television picture tube can throw.

The assembled core 10 comprises a first pair ^j A and B ₁ have the same shape, and a second pair C and D ₁ are also identical in shape. Therefore, only two forms are required to form the core parts. All first pairs of pieces A and B have two flat contact or mating surfaces

13 and 14, respectively 15 and 16, which are in one and the same Lie level and are separated from each other by part of the inner circumference. In the preparation of these parts made of ferrite material cast the powdered metal oxide components or precalcined Ferrite powder molded and sintered or fired at about 980 to 1315 ° C or more. While the firing occurs a certain shrinkage or change in shape, so that the mating surfaces 13 and

14 etc. are not even. Furthermore, the two surfaces 13 and 14 or 15 and 16 are located after No longer burn in exactly the same plane. the

<m 52S / 237

both mating surfaces of the individual pieces A and B are therefore ground to a narrow tolerance, namely, together, in a single plane. Sintered metal core parts can be made in a similar manner.

Both second pair parts C and D have two parallel fitting surfaces 17 and 18 and 19 and 20, respectively. Since the surfaces 17 and 18 run parallel to one another, these two surfaces can also be ground plane-parallel at the same time, or an already ground surface can be used to properly take care of the other surface for parallel grinding. Too much or too little when grinding the surfaces 13, 15, 14, 16, 17, 19, 18 or 20 does not lead to a large change in the fit, as is the case with radially fitting surfaces of conventional cores. It should also be noted that parts C and D can be displaced upwards or downwards with respect to parts A and B , as can be seen in FIG. 1, without the distances between the mating surfaces changing. In this way, small differences in the diameter of the neck part of a television tube can be compensated for and small accidental displacements of the parts do not produce any change in their effective permeability.

The opening 23- of the assembled Torah can thus be designed in such a way that it follows the respective shape of the cathode ray tube to be enclosed 40 adapts. Thus, the opening 23 can have an approximately tubular part 21 and one after it have part 22 expanding on the outside.

In operation, the core parts are mounted around the cathode ray tube 40, as shown schematically in FIG Fig. 3 is shown. The coil pair 41 and 42 for one vertical deflection is bent to fit snugly against the conical portion of tube 40. The spools 43 for horizontal deflection, only one of which is shown, are shaped similarly to the coils 41 and 42. The horizontal and vertical deflection coils are suitably configured, e.g. B. by thin insulating foils, insulated from one another. The four pieces of the yoke core 10 completely enclose the deflection coils 41,42,43 etc. and form one magnetic circuit for the magnetic flux. The angle α indicates a deflection of over 90 °, such as it can be achieved by such a device. The parts of the core 10 are through a Clip 45 held in place.

Claims (1)

Claim: Four-part ferromagnetic yoke core for the magnetic deflection of cathode rays in cathode ray tubes, characterized in that the yoke core consists of a pair (A, B) of parts each with two ground mating surfaces (13, 14 and 15, 16) in the same plane and a second A pair (C, D) of parts each with two plane-parallel, ground mating surfaces (17, 18 and 19, 20) consists (Fig. 1). Considered publications:
Swiss patent specification No. 295 824. 1 sheet of drawings © 009 528/237 5.60