US2545348A - Cathode-ray tube support - Google Patents

Description

March 13, 1951 G. w. FABEL CATHODE-RAY TUBE SUPPORT Filed Jan. 15, 1950 w 1 m P twfio T EMM 1% H G Patented Mar. 13 1951 CATHODE-RAY TUBE SUPPORT George W. Fabel, Fulton, N. Y., assignor to General Electric Company, a corporation of New York Application January 13, 1950, SerialNo. 138,487

6 Claims.

My invention relates generally to cathode ray tubes and, more particularly, to means for supporting cathode ray tubes within the cabinet of a television receiver. While my invention is of general utility, it is particularly suitable for use in television receivers which employ a cathode ray tube having a metal cone which is operated at a relatively high potential.

Certain types of cathode ray tubes recently placed on the market have employed a metal cone which is secured to the glass face plate of the cathode ray tube by a suitable glass-to-metal seal. Since the inner surface of the cone is used as the accelerating anode for the cathode ray tube and the cone is conductive, the entire metal cone is operated at the relative high potential necessary for the accelerating anode. In many instances this accelerating potential may be of the order of 15,000 volts or higher. In mounting such a cathode ray tube in the cabinet of a television receiver, great difficulty is experienced in reducing leakage from the highly charged metal cone to the surrounding portions of the cabinet. Also, in mounting such cathode ray tubes, means must be provided to prevent corona discharge from the metal cone to surrounding objects at ground potential. Additionally, the supporting means must .provide a good mechanical support for the cathode ray tube which is generally of relatively large diameter. Accordingly, it is a primary object of my invention to provide a new and improved support for the cathode ray tube of a television receiver.

It is a further object of my invention to provide a new and improved mounting means for a cathode ray tube of the metal cone type which is particularl suitable for use in television receivers, and which is of simple construction and low cost.

It is another object of m invention to provide a, new and improved support for cathode ray tubes of the metal cone type wherein corona dischargeto points of ground potential is substantially eliminated.

It is still another object of my invention'to provide a new and improved support for a cathode ray tube of large diameter wherein the oathode ray tube is rigidly supported within the cabinet of a television receiver.

It is a still further object of my invention to provide a support for a cathode ray tube of the metal cone type wherein leakage from the metal coneof-the cathode ray tube to the cabinet of the receiver si minimized.

The features of my invention which I believe.

' the front panel H.

to be novel are set forth with particularity in the appended claims. 7 My invention itself, however, both as to its organization and method of operation, together With further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing, in which Fig. 1 is a side elevational View partly in section of a cathode ray tube support employing the principles of my invention, Fig. 2 is a rear elevational view of the structure of Fig. 1 taken along the line 2-2 thereof, and Fig. 3 is a cross-sectional view of a portion of Fig. 2 taken along the lines 3-3 thereof.

Referring now more particularly to the drawing, I have illustrated therein a television cabinet indicated generally at I within which is mounted a cathode ray tube indicated generally at 2. The cabinet l-is provided with a transparent safety plate 3 behind which is positioned a mask 4. The mask 4, which may be of any suitable material such asrubber or the like, is provided with an aperture which defines the viewin area of the cathode ray tube. The cathode ray tube is provided with a metal cone 5 and a, curved transparent face plate 6 which is secured to the base of the cone 5 bya suitable glass-to-metal seal. The cabinet l is provided witha top meme her. it] and a front panel member H. The safety plate 3 may be secured to the front panel H by any convenient means such as the thumb screw l2, or the like.

In order to mountthe cathode ray tubel within the cabinet I in a manner substantially to prevent leakage to the cabinet and corona discharge from the metallic cone of the cathode ray tube, I provide a pair of support members 55, it which extend substantiall vertically within the cabinet I. The support members [5, l6 are supported at their extreme ends within the cabinet and spaced somewhat behind the front panel H. The support members l5, l6 are preferably constructed of a suitable insulating material such a polystyrene or the like having a relatively high dielectric constant so as to reduce leakage from the cathode ray tube to the cabinet of the receiver. Thus, for example, the upper end of support member I6 is secured to a spacing member I: by means of a suitable screw l8 or the like, so as to space the member it somewhat behind It will be understood that similarspacing blocks (not shown) are provided to support the other ends of support member l5, l6 so that these members are positioned in spaced, parallel relation to the front panel of the receiver. In this connection it will be understood that the problems of minimizing leakage to the cabinet and suppressing corona discharge are separate and distinct. Leakage results from a relatively low resistance path between the highly charged cone and ground potential which causes angle serving as a support for the rim of the cathode ray tube and the other arm of the right angle acting as a centering means therefor.

Thus, referring to Fig. 2 wherein the relative positioning of these members is clearly illustrated, the support members !5, l61which are supported from the cabinet at the extreme ends thereof, contact the cathode ray tube cone at the points [9 and 25. One arm 3| of the support member acts as a support against which the rim of the cathode ray tube cone may be held. The other arm 32 of the support member 15, which arm extends perpendicularly to arm 3|, prevents the cathode ray tube rim from moving sideways thereby positioning the face of the cathode ray tube for proper viewing of the screen thereof. As is well illustrated in Fig. 2, the supporting members l5, l6 contact the rim of the cathode ray tube for a relatively short distance along the length thereof and a substantial leakage path is provided from the supported end of each support member to the points of contact with the metal rim of the cathode ray tube. In order to reduce corona discharge from the highly charged metal cone to points on the support members |5, I6, I provide all corners of the right angle support members with a substantial radius so that the electric field distribution between the cone and the corners of the right angles does not become so concentrated as to cause breakdown therebetween.

The support members 55, 16 are spaced from the front panel of the receiver by an amount just sufiicient to enable the face plate ii of the cathode ray tube to be positioned adjacent the rear face of the mask 4. By such an arrange,- ment, the leakage path for the cathode ray tube is through air to all parts of the cabinet except through the relatively long leakage paths pro vided by the support members i5, 15.

In order securely to hold the rim of the oathode ray tube against the right angle support members l5, I6, I provide a pair of elongated cross members 2| 4|, which are positioned transversely of the axis of the metal cone 5 and are adapted to engage the sloping surfaces of the cone at oppositely spaced points thereon. The cross members 2|, 4| are movable back and forth within the cabinet so that they may be moved forward to a point where the central portion of the cross members engages the surface of the cone and exerts sufiicient pressure thereon securely to engage the base of the cone with the center portion of the support members l5, It.

In order to support the cross members 2|, Elv in such a manner that they may be readily moved forward and backward within the cabinet, I provide a plurality of brackets 22, which are secured to the side panels of the cabinet by any suitable securing means, such as the screws 23, or the like. The brackets 22 are provided with horizontally extending portions 24 which are slotted to receive a bolt 25 and wing nut 25. Suitable openings are provided in the ends of the cross members 4|, 2| so as to receive the bolts 25. The cross members 4|, 2! may conveniently be made of suitable hardwood doweling in which case sections of tubing 3!] are placed over the cross members 4|, 2| for a substantial portion of the length thereof. The tubing 30 is preferably constructed of a suitable insulating material having a high dielectric constant so as to provide adequate leakage paths back to the cabinet wall.

Fig. 2 clearly illustrates the relative positioning of the metallic cone 5 of the cathode ray tube and the cross members 4|, 2|. It is evident from this figure that the cross members 4|, 2| contact the sloping surface of the cone at a point intermediate the ends thereof, and that a substantial leakage path is provided from the point of contact of the metal cone to the sides of the cabinet.

In operation, a cathode ray tube is first placed within the arms 32 of the support members l5, l5 and held against the arms 3| of these support members with the face plate of the cathode ray tube in correct position for viewing a reproduced picture. The cross members 3!, 2| are then moved forward towards the front panel so as to clamp the metal cone of the cathode ray tube between the support members i5, i6 and the cross members 4|, 2|. By such an arrangement, the cathode ray tube is securely held in position for viewing through an aperture in the front panel of the receiver and substantial leakage paths are provided from all points of the metal cone of the cathode ray tube to the surrounding cabinet structure. By providing elongated cross members having curved surfaces at the point of engagement with the metal cone, a radius to radius contact is made between the cross members and the metal cone which operates substantially to reduce corona discharge from 1e highly charged cone 5 to the supporting rods ti, 2|. Also, due to the fact that the support members I5, 55 contact only the front rim of the cathode ray tube and then only for a relatively short distance along the rim on each side, leakage from the highly charged metal cone to the cabinet is substantially prevented.

In Fig. 3 there is illustrated more clearly the relative positioning of the metal rim of the oathode ray tube and the right angle support members l5, H5 at the points of contact therebetween. In Fig. 3 it is seen that the metal cone 5 termi nates in a rim portion 45 which conforms to the inner surface of the upper arm 32 of the right angle support and is provided with a curved portion 46 which contacts the lower arm 3i of the right angle support. This figure also illustrates that the corners 4'! of the right angle support members are provided with a relatively large radius to reduce corona discharge between the cone and the right angle support members.

From the foregoing, it is evident that the present invention provides a supporting means for a cathode ray tube of the metal cone type in which substantial leakage paths are provided to all points of the cabinet although the face plate of w the cathode ray tube is mounted substantially adjacent the front panel of the receiver. In addition, corona discharge from the highly charged metal cone of the cathode ray tube is substantially prevented by providing radius to radius contacts between the supporting members and the metal cone;

While the invention has been described by reference to particular embodiments thereof, it will be understood that numerous modifications may be made by those skilled in the art Without departing from the invention. I therefore aim in the appended claims to cover all such equivalent variations as come within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a television receiver of the type employing a cathode ray tube adapted for viewing the screen thereof through an aperture in the front panel of the cabinet of the receiver, said cathode ray tube having a metal cone adapted to be energized to a high potential, means for mounting said cathode ray tube while substantially preventing corona discharge to said cabinet comprising, a first pair of support members engaging the rim of said cone at diametrically opposed points thereon, the ends of said support members being supported within said cabinet so asto permit viewing of the screen of the cathode ray tube through said aperture, and a pair of rod-like cross members positioned to engage the sloping surface of said metal cone at diametrically opposed points along a periphery of somewhat smaller diameter than the maximum diameter of said cone, and means for moving the ends of said cross members towards said support members thereby securely to clamp said cone between said support members and said cross members.

2. Means for mounting a cathode ray tube of the metal cone type within the cabinet of a television receiver comprising, a plurality of insulated support members adapted to engage the rim of said cone and having a relatively long leakage path to said cabinet, said support members being positioned within said cabinet so as to permit viewing of said cathode ray tube through an aperture in said cabinet, and a plurality of rod-like cross members positioned transversely of the axis of said cone and adapted to engage the sloping surface of said cone at spaced points thereon, and means for supporting said cross members from said cabinet with the curved surface thereof in engagement with said cone thereby securely to clamp said cone between said supporting merfibers and said cross members.

3. Means for mounting a cathode ray tube of the metal cone type within the cabinet of a television receiver comprising, a plurality of insulated support members adapted to engage the rim of said cone and having a relatively long leakage path to said cabinet, said support members being positioned within said cabinet so as to permit viewing of said cathode ray tube through an aperture in said cabinet, and a plurality of rod-like cross members positioned transversely of the axis of said cone and adapted to engage the sloping surface of said cone at spaced points thereon, and means for supportin said cross members from said cabinet with the curved surface thereof in engagement with said cone thereby securely to clamp said cone between said supporting members and said cross members, said cross members having a' relatively long leakage path from the point of contact with said cone to said cabinet.

4. Means for mounting a cathode ray tube of the metal cone type within the cabinet of a television receiver comprising, means for supporting the rim of said cone in a position to permit viewing the screen of said cathode ray tube through an aperture in said cabinet, said supporting means being constructed to restrain said cone against axial movement towardsaid aperture, and a plurality of elongated cross members adapted to engage the sloping surface of said cone at spaced points on said cone remote from the rim thereof, and means for supporting the ends of said cross members from said cabinet with the intermediate portion thereof in engagement with said cone thereby securely to clamp said cone between said rim supporting means and said cross members.

5. Means for mounting a cathoderay tube of the metal cone type within the cabinet of a television receiver comprising, means for supporting the rim of said cone in a position to permit viewing the screen of said cathode ray tube through an aperture in said cabinet, said supporting means being constructed to restrain said cone against axial movement toward said aperture, and a plurality of elongated cross members adapted to engage the sloping surface of said cone at spaced points on said cone remote from the rim thereof, each of said cross members having a curved surfac at the point of contact with said cone thereby substantially to reduce corona discharge between said cone and said cross members, and means for supporting the ends of said cross members from said cabinet with the intermediate portion thereof in engagement with said cone thereby securely to clamp said cone between said rim supporting means and said cross members.

6. Means for mounting a cathode ray tube of the metal cone type within the cabinet of a television receiver comprising, means for supporting the rim of said cone in a position to permit viewing the screen of said cathode ray tube through an aperture in said cabinet, said supporting means being constructed to restrain said cone against axial movement toward said aperture,

and a plurality of elongated cross members adapted to, engage the sloping surface of said cone at spaced points on said cone remote from the rim thereof, each of said cross members having a curved surface at the point of contact with said cone thereby substantially to suppress corona discharge from said cone to said cross members, and means for supporting the ends of said cross members from said cabinet with the intermediate portion thereof in engagement with said cone thereby securely to clamp said cone between said rim supporting means and said cross members, said cross members having a relatively long leakage path from the point of contact with said cone to said cabinet.

GEORGE W. FABEL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,470,620 Jackson May 17, 1949 2,484,345 Hinz Oct. 11, 1949

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