US2319691A - Cathode ray tube and process - Google Patents

Description

May 18, 1943 s. J. KOCH ETAL CATHODE RAY TUBE AND PROCESS Filed May 29, 1942 3? 6 44/ INVENTORS HTTO/PNEV support 2 is inserted in the neck I.

"Patented May 18, 1943' cs'rnonn an runs is rnocsss Stanley J. Koch, Clifton, and Robert E. Rutherford, Rutherford, N. L, aasignors to Allen B. Du Mont Laboratories, 1110., Passaic, N. 1., a

corporation of Delaware Application May 29, 1942, Serial No. 444,961

14 Claims.

This invention relates to a cathode ray tube and the process oi producing the same. The tube is of the sort in which the electrical gun assembly is attached to and supported by the conductors that pass through the glass press of the tube.

By this invention the conductors are sealed in place in such a way that they are spaced as far apart as is feasible since they are located on the circumference of a circle that is almost as large as the inside of the neck of the tube. In this way the wires are placed so far apart that there is maximum insulation between them. Also a. very large exhaust tubulation can be used, thus facilitating rapid pumping of the tube alter the tubulation has been sealed in place.

The invention will be understood irom the description in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal section through the neck 01' a tube along the line l-l of Fig. 2;

Fig. 2 is a section along the line 2-2 of Fig. 1:

Figs. 3 and 4 are longitudinal sections on an enlarged scale partly broken away showing steps in the process of manufacturing the tube; and

Fig. 5 is a section along the line 5-5 of Fig. 4.

In the drawing, reference character I indicates the neck of a cathode ray tube. A mandrel or This mandrel is provided with a circular series oi. longitudinally extending holes 3 near its outer edge and a larger central longitudinally extending hole 4 at its center. An integral extension I in the form of a truncated cone is provided at the upper end of the mandrel 2. I 4

The exhaust tabulation comprises a central tube 8 having a flange 9 with recesses or scallops along its outer edge. These recesses may be made by heating the edge of the flange and pressing inwardly and downwardly with a rod of suitable diameter at spaced intervals, thus producing the recesses I. and leaving an inwardly curved integral depending flange or lip I I at each recess III.

The tubulation 8 is placed upon the mandrel 2 with the flange 9 resting upon the extension 5. Wires I2 having glass beads I3 fused thereon pass through the holes 3 of the mandrel 2 with the beads I! in the recesses ll, with these beads fitting in these recesses and in the curved lips II.

The disc I4 is of mica and is provided with holes I5 therethrough with eyelets I. in these holes. The conductors or wires [2 pass through the eyelets l6, thus supporting this disc and the un structure of the tube, not shown.

- After the parts are assembled as indicated in place.

After the sealing is finished the exhaust tubu- Fig. 1 they are inserted into the neck I of the tube with the edge of the flange I fitting the neck I. Heat is then applied at the level of the torch it around the whole circumference to fuse a circular area of the glass of the neck I, the beads It; the lips II and edge of flange 9 together so that they become integrated as indicated in Figs. 4 and 5 with the wires I! close to the inside surface of the wall of the neck I. One or more blow torches may be used to apply the heat to the outside of the neck I on a level with the beads I and the tube or'the torches may be rotated while the heating takes place. Any excess portion of the neck I-below the heating zone may be permitted to drop off or the beads I3 and heating zone may be located so near the end of the neck I that no excess glass needs to be removed. By proportioning and locating the glass elements with respect to each other the tubulation with the neck I can be made in such a manner that no excess glass needs to be removed and a smooth hermetically sealed joint without excessive thickness results.

With this invention it is not necessary to make a glass press through which the conductors or wires are hermetically sealed and subsequently heat this press to seal it to the tube because the same' heating that seals the disc I to the tube neck I also hermetically seals the wires I2 in lation 8 is attached to a vacuum system and the tube is pumped out to exhaust the air in the known way and sealed oil.

The entire gun structure of a cathode ray tube can be mounted upon the wires I2 and disc I4 and adjusted and inserted into the neck I of the glass tube preparatory to the heat sealing and evacuating steps. This invention is applicable to vacuum tubes in general as well as cathode ray tubes. v

What is claimed is:

1. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulatio'n having a flange with a serrated edge and having electric conductors in the serrations and applying suilicient heat to said neck and flange to fuse them together.

2. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a glass beaded flange with a serrated edge and having electric conductors in the serjunction of the rations and applying sumcient heat to said neck and flange to fuse them together.

3. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a glass beaded flange with a serrated edge and having electric conductors in the serrations, said serrations being substantially the size of said. beads and applying suiflclent heat to said neck and flange to fuse them together.

4. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a flange with a serrated edge and depending portions and having electric conductors in the serrations and applying suflicient heat to said neck and flange to fuse them together.

5. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a glass beaded flange with a serrated edge and depending portions curved to accommodate the beads and having electric conductors in the serrations and applying sumcient heat to said neck and flange to fuse them together.

6. In the process of producing a cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a flange with a serrated edge and having electric conductors in the serrations, and applying heat to the outside of said neck in proximity to said flange.

7. In the process of producing a,cathode ray tube, the steps which comprise introducing into the neck of a glass tube an exhaust tubulation having a flange with a serrated edge and havin electric conductors in the serrations, and applying heat to the outside of said neck in proximity to said flange until said neck, beads and flange are fused together.

8. A vacuum tube element comprising an exhaust tubulation having a serrated flange.

9. A vacuum tube element comprising an exhaust tubulation having a serrated flange and depending lips at the serrations.

10. A vacuum tube element comprising an exhaust tubulation having a serrated flange and depending inwardly curved lips at the serra-- ,tions.

11. A vacuum tube assembly comprising an exhaust tubulation having a serrated flange and beaded wires in said serrations.

12. A vacuum tube assembly comprising an exhaust tubulation having a serrated flange with depending portions at the ends of the serrations.

13. A vacuum tube assembly comprising an ex haust tubulation having a serrated flange with depending curved portions at the ends of the serrations.

14. A vacuum tube assembly comprising an exhaust tubulation having a serrated flange and headed wires in said serrations. the diameter of the respective beads on the wires being substantially the same as the transverse dimension of the corresponding serration.

STANLEY J. KOCH. ROBERT E. RUTHERFORD.

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