US3201637A - Cathode ray tube gun assembly - Google Patents

Description

Aug. 17, 1965 J. vv. SNYDER 3,2%537 CATH'ODE RAY TUBE GUN ASSEMBLY Filed oct. 24, 1961 INVENTOR. F7 C72 2. Jon/1v W. mo/DER United States Patent O 3,201,637 CTHDE RAY TUBE GUN ASSEMBLY .lohn William Snyder, Hatfield, Pa., assigner, by mesne assignments, to ihiico Cerporatien, Philadelphia, Pa., a corperaticn oi elaware Fiied Set. 24, i963, Ser. No. 147,270 3 Claims. (Cl. 313-256) This invention relates generally to cathode-ray tubes, and more particularly to improvements in cathode ray tube gun assemblies. The invention, while applicable in its broader aspect to cathode ray tubes generally, will be described and illustrated in relation to eonstricted neck tubes, Where it has special utility.

In the assembly of electron guns for cathode ray tubes and the like, it has been the practice to bind the metal electrode elements by insulators which are viscous at the time of application, but which later solidify into rigid insulating members. Attachment, or binding, of the metal parts to the insulating members is facilitated by means of axially aligned studs or brackets attached to and extending radially from the aforementioned metal parts. The insulating members have comprised parallelly disposed glass rods heated to a suitable viscous state and applied individually to one radially extending axially aligned set lof studs at a time. in the assembly of electrode elements of gun structure comprising, for example, a plurality of glass rods, the rods must be heated individually, in succession, in order to complete the assembly. In a high production volume of gun structures in which such electrode assemblies are utilized, a separate heating and cooling operation in attaching each insulator represents a considerable time factor in the overall production rate.

Also there has been increased demand for more compact television picture tubes of large iluorescent screen area. ing tube depth have involved increasing the electron beam deflection angle and reducing the length and diameter of the tube neck within which the electron gun is disposed. As to reduction of the dimensions of the tube neck, difteulties have been encountered in that the above described glass rod-supported gun structure does not lend itself to a reduction in diameter to the extent required. The present invention is directed primarily to overcoming these difficulties.

It is therefore a general objective of the invention to provide a novel electron gun structure permitting reduction in the dimensions of the neck of a cathode ray tube through a unique arrangement of insulating and support structure. This objective the invention has in common with the invention described and claimed in the copending application of Samuel H. Borrnan entitled Cathode Ray Tube Gun Structure, Serial No. 146,952, iiled October 23, 1961, and assigned to the assignee of the present invention.

It is a further general objective of the invention to provide both a method of and means for effecting highly accurate assembly of the elements of electron gun structure in a minimum of space.

It is also an objective of the invention to provide a simpliiied and improved assembly of axially aligned tubular metallic parts, such for example as electrode elements of a cathode ray tube gan structure of the type disclosed in the eopending Borrnan application, and further to provide a rapid, economical, and a highly accurate assembly of the parts in the desired rigid predetermined alignment and in the necessary inuslated spaced relation.

The invention is featured by the provision of an electron gun which is very simple yet very rigid in construction. It is an additional feature of the invention that Efforts toward achieveing compactness by reduc` 32mb?? Patented Aug. l?, i965 Cce it eliminates the aforementioned heating and cooling of insulating support members which heretofore had often resulted in distortion and misalignrnent of the elements of the gun structure, constituting a major problem.

In accordance with the foregoing and other objectives, the invention is characterized by provision of a hollow ceramic cylinder in which the metal parts of the gun structure are disposed. The ceramic cylinder includes means defining transversely extending apertures corresponding to locations lof points of fixation of the gun parts thereto. According to the invention, irregularly shaped metal elements, such for example as studs, extend through the apertures and are spot Welded in place to the metal gun parts. Each stud is so constructed and arranged as to form a three point Contact between the gun part and an aperture in the ceramic cylinder. When two or more portions of each metal gun part are secured by this method a permanent accurate alignment thereof is achieved by utilizing an annular space of but ls inch thickness or less.

in further accordance with the invention, the irregu larly shaped metal studs are formed by slicing a metal rod at an angle with respect to a plane perpendicular to the axis of the rod. This angle of cut insures that when V a stud extends through an aperture, it engages the metallic gun part at one point for connection thereto and frictionally engages the ceramic cylinder Wall at two points, thereby forming a three point supporting contact.

It is a feature of the invention, by way of comparison, that Whereas electron gun structure heretofore held together by glass rods required a ll/s inch diameter glass tube neck, the present invention permits use of a glass tube neck of but Sli inch in diameter.

The reduction in diameter afforded by .the invention is invaluable 'when it is Iconsidered that it -meets the requirement that the turn-s of the coils forming lthe deflection yoke Ashould be so disposed and conttigured as to be in close proximity to the electrons of the scanning beam. This arrangement ensures production of the highest possible magnetic iield intensi-ty and hence the application of a maximum deiiecting force to the ,beam electrons emitted from the gun structure. in other Word-s the invention enhances operation of the cathode-ray tube because the deiiection yoke is able to operate with maximum eiicien-cy.

The foregoing as Well as other objects and advantages of the invention lwill .best be understood upon consideration of the Lfollowing description Ktaken in light of the accompanying drawing, in which:

FIGURE l is an elevational showing, partly in section and with parts broken away, of a cathode ray tube ernbodying gun structure made in accordance with the invention;

FIGURE 2 is a somewhat enlarged `fragmentary showing, partly in section, of ,the gun structure shown in FIG- URE 1 and illustrating also techniques util-ized in assembling same and characteristic of the invention in its method aspect; and

lFIGURES 3 and 4 illustrate additional techniques of gun stucture assembly which also characterize the invention in its method aspect.

With more particular reference to the drawing, and iirst to FIGURE 1 thereof, cathode ray tube 16 is provided -With a generally cylindrical neck portion 151 having .a iiat end 4portion 112 through which electrically conductive terminal pins 13 extend.

Gun structure lllt made according to the invention is disposed within neck porti-on 1li and is supported from the left and right hand pins .13 as shown in FIGURE 1. Gun structure 14- cornprises a cathode heater :15 disposed Within Aan indirectly heated cathode sleeve fl iover the end of which is disposed electron emissive material Sleeve \`16 is spaced relative to and supported within generally cylindrical control grid 2d by a suitable insulative disk .17 and a resilient `washer 18 that frictiona'lly engage the grid 2'1. The spacing of sleeve 16 is such that emissive material 20 is disposed adjacent a .small opening 2%2 provided in a flat wall portion of the grid 21.

Grid 21 is supported from pins 13, and as indicated tially .enclose-s control grid 21. Sleeve 23 is supported by grid 21 through the agency of bracket means which compri-ses .s-tud'elements 24 that are aixed .to grid 2l* and extend into apertures .25, the latter extending through` sleeve 23 generally transverse the .axis thereof. The stud elements .24 are inclined with respect to and yfrictionally engage the walls of apertures 2S in the manner best seen in FIGURE 2 which illustrates the present inventive mode of frictional engagement of stud elements 24 with the ceramic sleeve.

In FIGURE l, and in further accordance with constru'ctional features of gun structure A14, ygenerally cylindrical apertured screen grid 26 and a third grid 350 are Supported in spaced relation las respects one another and concentrically with sleeve :23. Finally, the `anode 3d is supiported in like manner by additional stud elements 24 of .the bracket means, which anode 31 comprises a cornbined getter ring 312 and -snubber means 33 disposed in electrical contact with .an electrically conductive coating (not shown) that extends over interior surface portions 34 of tube 10. Electrical connections of the above described components -are made tothe pin means 13 and to the conductive coat-ing through means 33 by ribbon-like lead wires 37.

Additional important features of .the invention will now be described with particular reference to FIGURES 2, 3, and 4. yIrregularly shaped, .prism-like bits of metal comprise stud element-s 24 of the bracket means and are form-ed by slicing a cylindrical metal rod 24a (FIGURE 3) at an angle with respect to a plane perpendicular to .the .axis of the rod. An angular cut of 20 has been found satisfactory, Iwhich cut insures that when the stud element 24 is inserted into an upwardly presented aperture .215 (FIGURE 2) it will be so inclined therein as to engage the underlying grid .at one point and the ceramic sleeve 23 at two points in .a frictional, wedge-likemanner.

The invention will be still more clearly understood from .a description of the inode of assembly, in which connection it is seen in FIGURE 4 that the apertured cylinder 2B is clamped by set screw 36 in a .fixture 35 having a mandrel .portion 4t? disposed ttor axial alignment with the cylinder. The Vdiameter of portion 40 corresponds to the inside -diameters of the cylindrical element-s 26, 3l) .and 311 ywhich have been positioned thereon in the desired spaced relation as respects one another and cylinder 23. `Additional alignment of grid'element 26 is provided by a central pin-like projection 41 of mandrel' portion 40, said projection extending through the aper- -ture in the element 26. I

With the component elements assembled according to the showing of FIGURE 4, and with the .apertures 25 preferably presented upwardly, stud elements 24 are inserted into `apertures 25 as best seen in the enlarged showing afforded by FIGURE 2. With reference to VFIG- URE 2 it wi-ll be further appreciated that the stud elements also provide means for electrically connecting a lead wire 37 .to a cylindrical gun component.

With stud elements 24 positioned so that they are inclined as sho-wn lin .FIGURE 2, mild pressure is exerted on each such element by means of a resistance welding electrode as seen at 42 and a su-itable current passed between the element .24 .and the adjacent grid element 30 to weld the same together. Thus aixed to .the grid elea close size match with the stud elements 24..

ment, the stud elements will irictionally engage the walls of the apertures through which they extend whereby the attached gridv element is accurately supported. Connection of a lead wire 37 to a stud element is achieved by applying the weldingelectrode to wir-e 37 in the position shown in FIGURE 2 and again passing a sui-table weld ing current between the wire and the stud element. The fwelding electrode and suitable circuitry are conventional, and are shown only diagrammatically in FIGURE 2 as comprising ya voltage source L, an energizing switch S, transformer means T, and the lead wire connections re quired to eiect the welding current ovv. After welding the upwardly presented stud element-s 24, .the iixture 35 is rotated 180 about its axis to present the remaining apertures 25 upwardly and the stud insertion and welding operation is repeated as described above. understood that t-he invention contemplates use of any desired number of supporting stud elements, and is not limited to the number or the precise shape shown.

' It will further be understood that a similar operation is carried out in attaching the control grid 21 to sleeve 23, whereupon nal attachment of the remaining gun structure elements is made ias shown in FIGURE l.

The invention is featured by its simplicity of construction and ease of assembly, particularly when considered in light of the fact that the openings 25 need not provide Moreover, tolerances capable of being maintained in fabrication of ceramic elements of this type are not conducive to providing a uniform close size match, and this problem is readily overcome by the invention.

While but a single embodiment of the invention has been described, it will be understood that the invention is susceptible to modication, as is contemplated by the scope of the appended claims. Y

- IV claim: Y

1. In electron gun structure: a tubular electrode; a tubular member of electrically non-conductive material enclosing said electrode and having a common axis therewith; means defining a plurality ofapertures extending transversely'through said tubular member; and electrode supporting bracket means aixed to said tubular electrode, said bracket means comprising a plurality of rod elements each extending into an associated one ofV said apertures and each inclined as respects the major axis of its associated aperture and having portions of substantially lesser cross sectional area than said apertures, lan end portion of each said inclined rod element being aixed t0 said electrode and oppositely disposed axially spaced lateralportions thereof disposed in frictional electrode supporting engagement with walls of said apertures.

2. Gun structure according tov claim 1 characterized in that said tubular member is of a ceramic material.

3. In electron gun structure: tubular electrode means; an elongated electrically non-conductive member disposed adjacent said electrode means and having apertures extending transversely thereof and through said non-conductive member; and electrode supporting bracket means comprising rod-like elements each of substantially less cross-sectional tarea than and extending into an associated one of said apertures, each said element having a pair of oppositely disposed parallel face portions inclined as respects t-he major axis of said element, the construction and arrangement being such that engagement of a recited angular face portion with said electrode Veiiects inclined positioning of each said rodlike element within an aperture, as respects the major axis thereof, whereby an element engages opposite, axially spaced sides of an associated aperture frictionally to retain the electrode means in the recited supported relation.

4. In electron gunv structure: tubular electrode means; elongated electrically non-conductive insulative means disposed adjacent said electrode means and having apertures extending therethrough transversely of said tubular electrode means; and electrode supporting brackets comprising irregularly shaped pieces of metal Welded to said electrode means and having portions frictionally engaging both the edge and an opposite portion of the inside surfaces of the material defining said apertures.

5. In electron gun structure: electrode means; electrically non-conductive insulative means disposed adjacent said electrode means and having apertures extending therethrough transversely of said electrode means; and electrode supporting brackets comprising irregularly shaped pieces of metal welded to said electrode means and having portions frictionally engaging both the edge and an opposite portion of the inside surfaces of the material defining said apertures.

6. In electron gun structure: means defining a tubular electrode; a tubular member of electrically non-conductive material enclosing said electrode and having a common axis therewith; means defining a plurality of apertures extending transversely of and through said tubular member; and electode supporting bracket means aixed to said tubular electrode, said bracket means comprising a plurality of rod-like elements each extending into one of said apertures and having a pair of oppostely disposed parallel face portions positioned with angularity as respects its axis, the construction and arrangement being such that supporting engagement of a recited angular face portion with said electrode elfects inclined positioning of each said rod-like element within an aperture whereby such an element engages opposed, axially spaced sides of the aperture to retain the electrode means in the recited supported relation.

7. Gun structure according to claim 6 and further characterized in that each said rod element comprises a cylindrical section and said face portions comprise generally elliptical surfaces.

8. In electron gun structure: electrode means; electrically insulative means disposed adjacent said electrode means and having apertures extending therethrough transversely of said electrode means; and electrode means supporting brackets comprising rod-like elements each of substantially less cross-sectional area than an associated aperture and extending into the associated one of said apertures, said elements each having at least a transverse face portion positioned with angularity as respects the axis of the element, the construction and arrangement being such that supporting engagement of a recited angular face portion with said electrode means eiects inclined positioning of lthe rod-like element Within the associated one of said apertures, as respects the major axis thereof whereby the element engages sides of the associated aperture frictionally to retain the electrode means in the recited supported relation.

References Cited by the Examiner UNITED STATES PATENTS 2,372,649 4/45 Binneweg 313-244 X DAVID J. GALVIN, Primary Examiner. RALPH P. NILSON, Examiner.

Claims (1)

1. IN ELECTRON GUN STRUCTURE: A TUBULAR ELECTRODE; A TUBULAR MEMBER OF ELECTRICALLY NON-CONDUCTIVE MATERIAL ENCLOSING SAID ELECTRODE AND HAVING A COMMON AXIS THEREWITH; MEANS DEFINING A PLURALITY OF APERTURES EXTENDING TRANSVERSELY THROUGH SAID TUBULAR MEMBER; AND ELECTRODE SUPPORTING BRACKET MEANS AFFIXED TO SAID TUBULAR ELECTRODE, SAID BRACKET MEANS COMPRISING A PLURALITY OF ROD ELEMENTS EACH EXTENDING INTO AN ASSOCIATED ONE OF SAID APERTURES AND EACH INCLINED AS RESPECTS THE MAJOR AXIS OF ITS ASSOCIATED APERTURE AND HAVING PORTIONS OF SUBSTANTIALLY LESSER CROSS SECTIONAL AREA THAN SAID APERTURE, AN END PORTION OF EACH SAID INCLINED ROD ELEMENT BEING AFFIXED TO SAID ELECTRODE AND OPPOSITELY DISPOSED AXIALLY SPACED LATERAL PORTIONS THEREOF DISPOSED IN FRICTIONAL ELECTRODE SUPPORTING ENGAGEMENT WITH WALLS OF SAID APERTURES.

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