US3320457A

US3320457A - Two-piece apertured electrode for cathode ray tube electron gun provided with integral alignment means

Info

Publication number: US3320457A
Application number: US352609A
Authority: US
Inventors: Glen A Burdick; Floyd K Collins; Sr Ross K Gessford
Original assignee: Sylvania Electric Products Inc
Current assignee: GTE Sylvania Inc
Priority date: 1964-03-17
Filing date: 1964-03-17
Publication date: 1967-05-16
Anticipated expiration: 1984-05-16
Also published as: GB1059308A

Description

y 16, 1967 cs, A. BURDICK ETAL 3,320,457

TWO-PIECE APERIURED ELECTRODE FOR CATHODE RAY TUBE ELECTRON GUN PROVIDED WITH INTEGRAL ALIGNMENT MEANS Filed March 17, 1964 INVEN-rRs Glen A. Bard/ck F/oyd If. Coll/as Ross A, Gessl'ord, 5r.

ATTORNEY United States Patent Ofiice 3,320,457 Patented May 16, 1967 3,320,457 TWO-PIECE APERTURED ELECTRODE FOR CATH- ODE RAY TUBE ELECTRUN GUN PROVIDED WITH INTEGRAL ALIGNMENT MEAN Glen A. Burdick, Waterloo, N.Y., Floyd K. Collins, ttawa, Ohio, and Ross K. Gessford, S12, Seneca Falls, N.Y., assignors to Sylvania Electric Products Inc., a corporation of Delaware Filed Mar. 17, 1964, Ser. No. 352,609 9 Claims. (Cl. 31382) This invention relates to the alignment of a two-piece electrode structure and more particularly to alignment means integral to the two elements comprising a doubleended apertured electrode component used in an electron gun of a cathode ray tube.

In electron tube art it is conventional to fabricate twopiece electrode components by forming compatible pieces dimensioned to be slidably fitted and joined to one another. An example of this type of construction is found in certain types of cathode ray tube gun assemblies wherein a two-element dual apertured electrode is utilized as a double-ended anode structure. Such structure usually comprises two similarly formed elements each having an open end, a partially closed opposite end with a terminally formed aperture therein, and a substantially cylindrical body differing diametrically one from the other to facilitate the compatible telescoping of one cylindrical body within the other thereby providing a double-ended electrode having a terminally formed aperture at either end. These terminal aperture sections aid in forming the focusing lenses of the gun. Therefore, it is important that the aperture section be in axial alignment with the other gun electrodes. Any displacement or tilt of the electrodes causes the formation of electrostatic fields which are not axially symmetrical to the axis of the electron beam. Such fields distort the shape of the electron beam and result in loss of picture quality. A misalignment of .001 to .002 inch can cause a visible degradation of the picture evidenced on the screen of the tube.

The fabrication of substantially cylindrically shaped parts of the nature described is usually accomplished by a drawing operation in which it is necessary to have a slight longitudinal diametrical divergence in the parts to facilitate withdrawal of the male die. Parts formed in this manner are slightly larger in diameter at the open end than at the terminal aperture end. Thus, the achievement of accurate alignment through the telescopic assembly of such parts is a difiicult operation due to the presence of diametrical divergences and manufacturing tolerances.

Another aggravating factor is the cut of the open end of the shaped part. While intended to be orthogonal, the nature of the shear often imparts an open end plane that is slightly non-orthogonal to the axis of the part. This hinders alignment when the open end is utilized in seating one part relative to the other during electrode assembly fabrication. In addition, the welding procedure necessary to bond the assembled parts aggravates the misalignment situation, since, because of the loose fit between the parts, the first weld tends to tilt the inner part in one direction and subsequent welds sequentially applied promote out-of-roundness of the structure. Thus, misalignment of the two-piece, double-ended electrode has been a troublesome problem resulting in a considerable number of alignment rejects.

Accordingly, an object of the invention is to reduce the aforementioned disadvantages and to improve the fabrication of two-element electrode assemblies.

Another object is to provide positive alignment means integral to the parts assembled.

A further object is to reduce the number of alignment rejects normally occurring from the critical construction of the two-element, double-ended electrode assembly.

Another object is to provide integral alignment means that compensates for the inherent longitudinal diametrical divergences encountered in drawn parts.

An additional object is to provide integral alignment means that minimizes the elfect of the non-orthogonal ends in the telescoped parts.

The foregoing objects are achieved in one aspect of the invention by the provision of a two-element doubleended apertured electrode assembly comprising cooperating alignment means integral to each of the compatible parts. A first duo-diameter substantially cylindrical element, open at one end and containing an axial aperture in the other, is formed with an interior bearing surface. A second duo-diameter substantially cylindrical element, of similar basic construction, is of an outside diameter compatible for contiguous open-end telescoping within the first element. The sidewall of the second element is formed with integral bearing means formed to contiguously engage the bearing surface of the first element to achieve constrained placement and effect efiicient alignment of the apertures of the two elements. The simultaneous crimping of discretely spaced portions about the periphery of the open end of the first element rigidly engages the formed peripheral portion of the second element thereby effecting a centering action thereto in addition to locking the two elements in positive mated alignment.

For a better understanding of the present invention, together with other and further objects, advantages, and capabilities thereof, reference is made to the following disclosure and appended claims in connection with the accompanying drawings in which:

FIGURE 1 is a partially sectioned view showing an electron gun as utilized in a cathode ray tube;

FIGURE 2 is a sectioned view showing one embodiment of the invention;

FIGURE 3 is an end view of the type of embodiment illustrated in FIGURE 2 as viewed from line 33 of FIGURE 2;

FIGURE 4 is a sectioned view showing another embodiment of the invention;

FIGURE 5 is an end view of the type of embodiment shown in FIGURE 4 as viewed from line 55 of FIG- URE 4;

FIGURE 6 is a sectioned view showing still another embodiment of the invention;

FIGURE 7 is a plan view of the embodiment shown in FIGURE 6 taken along line 77 thereof showing cooperation of alignment means.

In FIGURE 1 there is shown a typical electron gun 11 as utilized in a conventional cathode ray'tube wherein a plurality of cooperating electrodes are spaced and electrically energized to produce and control a desired electron beam 13.

Explicitly, the electron gun 11 is shown comprising a cathode assembly 15 including a cylindrical sleeve portion 17 having electron emissive material 19 deposited on the closed end thereof. A heater 21 provides the heat necessary to cause electrons to be emitted from the emissive material 19 thereby comprising the source of electrons forming the beam 13. Spaced from the cathode assembly 15 along the path of electron travel is sequentially positioned in concentrical array a first apertured grid 21, a second apertured grid 23, an electron accelerating anode 25 having a first lens cup 27 with an axial aperture 29 therein and a second lens cup 3-1 with an axial aperture 33 therein, an electrostatic focusing cylinder 35, and a final anode structure 37 having a lens cup 39 with an aperture 41 therein. Each of the aforementioned electrodes have suitable attachment means 43 embedded in a plurality of ceramic gun supporting beads 45, one of which is shown.

Precise coaxial alignment of the apertures of the several gun electrodes is essential for desired operational efiiciency. The electron beam 13 which is directed and made convergent to provide a spot of minimum diameter on a cathodoluminescent screen, not shown, is focussed by the electron lens formed by the focusing assembly 40 comprising the final anode lens cup 39 and the anode second lens cup 31, having apertures 41 and 33 formed therein surrounded at their aperture regions by focusing cylinder 35. Partial prefocusing and beam accelerating is furnished by the anode first lens cup 27 in cooperation with the apertural configurations and spacings of the preceding first and second grids, 21 and 23 respectively.

Since the anode 25 is a two-element double-end apertured electrode structure, it is clearly evident that the first element 49, containing first lens cup 27, must be properly mated with the second element 51, containing second lens cup 31, to produce the desired coaxial alignment of

apertures

29 and 33 therein.

In greater detail, there is shown in FIGURES 2 and 3, one constructional embodiment of anode 25 whereby the desired degree of alignment is achieved by cooperating structral means integral to each element. A first duodiameter element 53, of a metal such as stainless steel, comprises a substantially cylindrical sidewall portion 55 separating an open end 57 and an opposing peripherally shouldered partial closure in the form of a smaller diametered first lens cup 27 having an aperture 29 therein. The peripheral shoulder 59 effects integral transition between the duo-diameter portions, 27 and 55 respectively. There is integrated within the first element 53 an interior bearing surface in the form of at least three substantially identical equi-spaced tapering longitudinal sidewall-shoulder indentations 63 projecting interiorly and extending from a portion 65 of the shoulder 59 along an adjacent area 67 of the sidewall portion 55.

While the indentations 63 are shown and described as being substantially of a straight taper, a common definition of the words taper, tapered or tapering as used in this specification, is intended to include straight, convex, and concave tapering manifestations or variants of the same.

A second duo-diameter metallic element 71, fabricated from a material like that of the first element 53 or of a material having a coefficient of thermal expansion no greater than that of the first element, comprises a substantially cylindrical sidewall portion 73 joined with a peripherally shouldered partial closure in the form of a smaller diametered second lens cup 31 having an aperture 33 therein. The integral transition between these

duodiameter portions

27 and 73 is effected by a peripheral shoulder 75 having an exterior peripheral surface 76 which is shown and described as being substantially rounded but could be in the form of a peripheral annular shoulder taper, not shown. The substantially cylindrical sidewall portion 73 is longitudinally shorter than the first element sidewall portion 55 for reasons to be later described. The end of the sidewall portion 73 opposite the shoulder 75 is peripherally formed with an inward tapered portion 79 defining a reduced diametrical opening 81. The taper of this sidewall portion 79 is such as to be engagingly compatible with the taper of the first element indentations 63. Ideally, constrained engagement between the tapers of the two elements should be consummated intermediate the ends of the first element taper by a substantial portion of the second element taper removed from the open end thereof.

Since the outside diameter of the sidewall portion 73 of the second duo-diameter element 71 is diametrically smaller than the inside diameter of the sidewall portion 55 of the first element 53, telescoping of the open end 81 of the second element sidewall portion 73 into the open end 57 of the first element sidewall portion 55 is compatibly facilitated. In this manner of element orientation, the peripherally tapered sidewall portion 79 of the second element 71 is brought into contiguous engagement with the plurality of tapering indentations 63 of the first element 53 to provide constrained concentrical placement, thereby facilitating alignment of the lens apertures of the two elements. It will be noted that the edge of the open end 81 of the second element 71 does not have seating engagement. Therefore, any non-orthogonal cut thereof does not materially affect alignment.

As aforementioned, the sidewall 73 of the second element 71 is longitudinally shorter than the sidewall 55 of the first element 53. A plurality of at least three substantially equi-spaced inward crimps are simultaneously applied about the peripheral portion of the wall 85 adjacent the open end 57 of the first element 53 to rigidly engage the rounded or annular tapered exterior peripheral surface of the shouldered portion 75 of the second element thereby providing equalized constrained concentricity to the second lens cup end of the telescoped sidewall portions. By this action, the two elements are locked together in positive mated alignment.

In another embodiment of the invention, as illustrated in FIGURES 4 and 5, the first element 89 is of duo-diameter construction, similar to that previously described in the first embodiment of the invention, having a cylindrical sidewall portion 91 and a first lens cup 27 integrally attached at peripheral shoulder 93. Instead of the tapering longitudinal indentations 63 of the first embodiment, this second embodiment employs, in the area adjacent the shoulder 93, an annular tapered sidewall portion 95 formed to join the adjacent cylindrical sidewall portion to a portion 97 of the peripheral shoulder 93. The inner surface of the annular tapered sidewall portion 95 provides a suitable interior bearing surface for the first element 89.

The second element 71 in this second embodiment is structurally the same as described for the first embodiment. By telescopically assembling the two elements, the peripherally slanted sidewall portion 79 of the second element 71 is brought into contiguous engagement with the annular tape-red sidewall portion 95 of the first element 89. The taper of the peripherally tapered sidewall portion 79 being compatible to the taper of the annular tapered sidewall portion 95 facilitates positive constrained concentrical seating for the two duo-diametered elements, 71 and 81, thereby provides desired apertural alignment of the resultant anode structure.

In this embodiment, as in the previously described embodiment, the substantially cylindrical sidewall portion 91 of the first element 89 is longitudinally longer than the sidewall portion 73 of second element 71. A plurality of at least three crimps or metallic deformations are inwardly effected at discretely spaced peripheral portions of the wall 99 adjacent the open end 101 of the first element 89 to rigidly engage the rounded or annular tapered exterior peripheral surface of the shouldered portion 75 of the second element 71 thereby providing equalized constrained concentricity thereto and a positive locking of the two elements together in seated alignment.

A third embodiment is shown in FIGURES 6 and 7. A first element 105, that is basically similar to the first elements previously described, has a substantially cylindrical sidewall portion 107 but is without indentations or formed sidewall tapers. The peripheral shoulder 109 joins the integral axial apertured first lens cup 27. The second element 113 has a substantially cylindrical sidewall portion 115 and a lens cup 31 integrally joined at a shoulder having a rounded exterior peripheral surface 126. The sidewall portion 115 has formed therein a plurality of at least three equi-spaced exterior longitudinal bosses 119 extending from an area 122 adjacent the open end 121 of the second element 113 to a point 123 in the substantially cylindrical sidewall 115 that is adjacent the peripheral shoulder 125. The minimum longitudinal length of these bosses should be at least half the longitudinal length of the sidewall portion 115. Preferably, the bosses should be oriented toward the open end of the element 113.

' As with the previous embodiments, the cylindrical sidewall portion 115 of the second element 113 is diametrically dimensioned to compatibly telescope within that of the first element 105. In this instance the diametrical measurements of the second element 113 are greatest in those areas where the longitudinal bosses 119 outwardly protrude being equal to or greater than the internal diameter of the first element 105. Thus, when the second element is telescoped within the first element, the longitudin-al bosses spacingly contact the inner bearing surface of the cylindrical sidewall of the first element to provide exacting alignment of the two elements. Therefore, it is import-ant that, as a minimum measurement, the outside diameter of the open end 121 of the second element 113, including the bosses, should be at least equal to the inside diameter of the cylindrical sidewall portion 107 of the first element 105 at substantially the half-way point 108 of sidewall portion 107 to consummate a constrained placement fit between the two elements. Here again, as in the aforedescribed embodiments, any non-orthogonal cut on the open end of the second element has little effect on the alignment since the edge performs n-o seating function.

In this embodiment, illustrated in FIGURES 6 and 7, as in the previously described embodiments, the cylindri-oal sidewall portion 115 of the second element 113 is longitudinally shorter than the cylindrical sidewall portion 107 of the first element 105. A plurality of at least three substantially equi-spaced simultaneously effected inward crimps about the peripheral portion of the wall 127 adjacent the open end 129 of the first element 105 rigidly engages the rounded or annular tapered exterior peripheral surface of the shouldered portion 125 of the second element 113. This crimping procedure provides equalized constrained concentricity to the two

elements

105 and 113 and locks them together in positive seated alignment.

Thus, there is provided for each element of a two-element electrode structure, integral alignment means compatibly formed to provide accurate alignment of the two elements by an inner concentrical constrained placement. The achieved alignment is further assured by a plurality of simultaneously applied and peripherally oriented crimps which rigidly engage and lock the two elements in concentrically seated relationship.

The bearing surfaces of the two elements are oriented to compensate for the inherent flare encountered in drawn parts, and the angled engagement of the bearing surfaces of the two elements promotes constrained placement that brings the elements into desired alignment and minimizes the presence of any non-orthogonal cut on the open end of the second element. A two-element electrode structure constructed in accordance with the above-described invention may be economically and efiiciently fabricated with a resultant assurance of alignment.

While there have been shown and described what are at present considered the preferred embodiments of the invention, it will 'be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention as defined by the appended claims.

What is claimed is:

1. In an electron gun structure of an electron discharge device having a longitudinal axis, a two-element doubleended apertured electrode having integral alignment means comprising:

a first element having a substantially cylindrical sidewall portion separating an open end and an opposing partial closure formed with an axial aperture therein, said first element having an interior bearing surface; and

a second element telescoped within said first element having a substantially cylindrical sidewall portion separating an open end and an opposing partial clo sure formed with an axial aperture therein, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element closure having an exterior peripheral surface, the outside diameter of said second element sidewall portion being diametrically smaller than the inside diameter of said first element sidewall portion to provide compatible contiguity therewith, said sidewall of said second element having bearing means to engage said bearing surface of said first element to provide constrained placement of said elements and alignment of said apertures therein, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of crimps discretely spaced and simultaneously applied about the peripheral portions of the first element sidewall adjacent the open end thereof in rigid engagement with the exterior peripheral surface of the closure portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements.

2. In an electron gun structure of an electron discharge device having a longitudinal axis, a two-element doubleended apertured electrode having integral alignment means comprising:

a first metallic element having a substantially cylindrical sidewall portion separating an open end and an opposing partial closure formed with an axial aperture therein, said first element having an interior bearing surface; and

a second metallic element telescoped within said first element, said second element being of a metal exhibiting a coeflicient of thermal expansion no greater than that of the first element, said second element having a substantially cylindrical sidewall portion separating an open end and an opposing partial closure formed with an axial aperture therein, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element closure having a rounded exterior peripheral surface, the outside diameter of said second element sidewall portion being diametrically smaller than the inside diameter of said first element sidewall portion to provide compatible contiguity therewith, said sidewall of said second element having bearing means to engage said bearing surface of said first element to provide constrained placement of said elements and alignment of said apertures therein, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of at least three crimps discretely spaced and simultaneously applied about the peripheral portion-s of the first element sidewall adjacent the open end thereof in rigid engagement with the rounded exterior peripheral surface of the closure portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements.

3. In an electron gun structure of an electron discharge device having a longitudinal axis, a two-element doubleended apertured electrode having integral alignment means comprising:

a second metallic element telescoped within said first element, said second element being of a metal exhibiting a coefficient of thermal expansion no greater than that of the first element, said second element having a substantially cylindrical sidewall portion separating an open end and an opposing partial closure formed with an axial aperture therein, said second element axial aperture being oppositely disposed to said first element axial aperture, said second eleshoulder of said first element along an adjacent area of said sidewall of the same in the region contiguous to said shoulder thereof; and

second duo-diameter element telescoped within said ment closure having an annular tapered exterior first element having a substantially cylindrical sideperipheral surface, the outside diameter of said secwall portion separating an open end having adjacent ond element sidewall portion being diametrically thereto a peripherally formed inward tapered sidesmaller than the inside diameter of said first element wall portion terminally defining a reduced diametsidewall portion to provide compatible contiguity rical opening and an opposite peripherally shoultherewith, said sidewall of said second element having 10 dered partial closure in the form of a smaller diabearing means to engage said bearing surface of said metered second lens cup having an axial aperture in first element to provide constrained placement of said the end thereof, said second element axial aperture elements and alignment of said apertures therein, being oppositely disposed to said first element axial the sidewall of said second element being longitudiaperture, said second element shouldered portion nally shorter than the sidewall of said first element, having a rounded exterior peripheral surface, the outsaid elements being locked together by a plurality of side diameter of said second element sidewall portion at least three crimps discretely spaced and simulbeing diametrically smaller than the inside diameter taneously applied about the peripheral portions of the of said first element sidewall portion to provide comfirst element sidewall adjacent the open end thereof patible contiguity therewith, said open end of said in rigid engagement with the annular tapered exterior second element being oriented toward the inner surperipheral surface of the closure portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements.

face of said peripheral shoulder of said first element, said peripherally tapered sidewall portion of said second element being in contiguous engagement with the plurality of said tapering indentations of said 4. In an electron gun structure of an electron discharge device having a longitudinal axis, a two-element double ended apertured electrode having integral alginment means comprising:

a first element having a substantially cylindrical sidefirst element to provide constrained placement of said elements and alignment of said aperture therein, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of Wall portion separating an open end having a substancrimps discretely spaced and simultaneously applied tially full diametrical opening and an opposing about the peripheral portions of the first element peripherally shouldered partial closure formed with sidewall adjacent the open end thereof in rigid enan axial aperture therein, said first element having a gagement with the rounded exterior surface of the discrete interior bearing surface; and shouldered portion of said second element to provide second element telescoped withinsaid first element equalized constrained concentricity thereto thereby having a substantially cylindrical sidewall portion separating an open end having adjacent thereto a peripherally tapered sidewall portion terminally defining a reduced diametrical opening end and an opposite peripherally shouldered partial closure formed with an axial aperture therein, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element shouldered portion having a rounded exterior peripheral surface, the outside diameter of said second eleand extending from a portion of said peripheral consummating desired apertural alignment of said elements.

6. In an electron gun structure of a cathode ray tube, a two-element double-ended apertured electrode having integral alignment means comprising:

a first duo-diameter element having a substantially cylindrical sidewall portion separating an open end having a substantially full diametrical opening and an opposing peripherally shouldered partial closure in the form of a smaller diametered first lens cup havment sidewall portion being diametrically smaller ing an axial aperture in the end thereof, said first ele than the inside diameter of said first element sidewall ment having a plurality of at least three substantially portion to provide compatible contiguity therewith, identical equi-spaced tapering longitudinal sidewallsaid peripherally tapered sidewall portion of said secshoulder indentations projecting interiorly and exond element affording 'bearing means to engage said tending from a portion of said peripheral shoulder bearing surface of said first element to provide conof said first element along an adjacent area of said strained placement of said elements and alignment sidewall of the same in the region contiguous to said of said apertures therein, the sidewall of said second shoulder thereof; and element being longitudinally shorter than the sidesecond duo-diameter element telescoped within said wall of said first element, said elements being locked first element having a substantially cylindrical sidetogether by a plurality of crimps discretely spaced wall portion separating an open end having adjacent and simultaneously applied about the peripheral porthereto a peripherally tapered sidewall portion tertions of the first element sidewall adjacent the open minally defining a reduced diametrical opening and end thereof in rigid engagement with the rounded an opposite peripherally shouldered partial closure in exterior peripheral surface of the shouldered portion the form of a smaller diametered second lens cup of said second element to provide equalized conhaving an axial aperture in the end thereof, said secstrained concentricity thereto thereby consummating ond element axial aperture being oppositely disposed desired apertural alignment of said elements. to said first element axial aperture, said second ele- 5. In an electron gun structure of a cathode ray tube, ment shouldered portion having a rounded exterior a two-element double-ended apertured electrode having peripheral surface, the outside diameter of said secintegral alignment means comprising: ond element sidewall portion being diametrically a first duo-diameter element having a substantially smaller than the inside diameter of said first element cylindrical sidewall portion separating an open end sidewall portion to provide compatible contiguity having a substantially full diametrical opening and therewith, said open end of said second element being an opposing peripherally shouldered partial closure oriented toward the inner surface of said peripheral in the form of a smaller diametered first lens cup shoulder of said first element, said peripherally taperhaving an axial aperture in the end thereof, said ed sidewall portion of said second element being in first element having a plurality of at least three subcontiguous engagement with the plurality of said stantially identical equi-spaced tapering longitudinal tapering indentations of said first element to provide sidewall shoulder indentations projecting interiorly constrained placement of said elements and alignment of said apertures therein, said constrained placement between the tapered portions; of said two elements being consummated intermediate the ends of the first element taper by a substantial portion of the peripherally tapered sidewall of said second element, the sidewall of saidsecond element being longitudinally shorter'th'an the sidewall of said first element, said elements being-locked together by a plurality of crimps discretely spaced and simultaneously applied about the peripheral: portions of the first element sidewall adjacent the open end thereof in rigid engagement with the rounded exterior surface of the shouldered portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements.

7. In an electron gun structure of a cathode ray tube,

a two-element double-ended apertured electrode having integral alignment means comprising:

a first duo-diameter element having a substantially cylindrical sidewall portion separating an open end having a substantially full diametrical opening and an opposing peripherally shouldered partial closure in the form of a smaller diametered first lens cup having a first axial aperture in the end thereof, said first element having in the circumferential area adjacent the shoulder an annular tapered sidewall portion formed to join said adjacent substantially cylindrical sidewall portion to a portion of said peripheral shoulder; and

a second duo-diameter element telescoped within said first element having a substantially cylindrical sidewall portion separating an open end having adjacent thereto a peripherally tapered sidewall portion terminally defining a reduced diametrical opening and an opposite peripherally shouldered partial closure in the form of a smaller diametered second lens cup having an axial aperture in the end thereof, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element shouldered portion having a rounded exterior peripheral surface, the outside diameter of said second element sidewall portion being diametrically smaller than the inside diameter of said first element sidewall portion to provide compatible contiguity therewith, said open end of said second element being oriented toward the inner surface of said peripheral shoulder of said first element, said peripherally tapered sidewall portion of said second element being in contiguous engagement with the inner surface of said annular tapered sidewall portion of said first element to provide constrained placement of said element and alignment of said apertures therein, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of crimps discretely spaced and simultaneously applied about the peripheral portions of the first element sidewall adjacent the open end thereof in rigid engagement with the rounded exterior surface of the shouldered portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements.

8. In an electron gun structure of a cathode ray tube,

a first duo-diameter element having a substantially cylindrical sidewall portion separating an open end having a substantially full diametrical opening and an opposing peripherally shouldered partial closure in the form of a smaller diametered first lens cup having a first axial aperture in the end thereof, said first element having in the circumferential area adjacent the shoulder an annular tapered sidewall portion formed to join said adjacent substantially I a second duo-diameter element, telescoped within said first element having a substantially cylindrical sidewall portion separating an open end having adjacent thereto a peripherally tapered sidewall portion terminally defining a reduced diametrical opening and an opposite peripherally shouldered partial closure in the form of a smaller diametered second lens having an axial aperture in the end thereof, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element shouldered portion having a rounded exterior peripheral surface, the outside diameter of said second element sidewall portion being diametrically smaller than the inside diameter of said first element sidewall portion to provide compatible contiguity therewith, said open end of said second element being oriented toward the inner surface of said peripheral shoulder of said first element, said peripherally tapered sidewall portion of said second element being in contiguous engagement with the inner surface of said annular tapered sidewall portion of said first element to provide constrained placement of said elements and alignment of said apertures therein, said constrained placement between the tapered portions of said two elements being consummated intermediate the ends of the first element taper by a substantial portion of said second element taper removed from the open end of said second element, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of crimps discretely spaced and simultaneously applied about the peripheral portions of the first element sidewall adjacent the open end thereof in rigid engagement with the rounded exterior surface of the shouldered portion of said second element to provide equalized constrained concentricity thereto thereby consummating desired apertural alignment of said elements. 9. In an electron gun structure of a cathode ray tube,

a first duo-diameter element having a substantially cylindrical sidewall portion separating an open end having a substantially full diametrical opening and an opposing peripherally shouldered partial closure in the form of a smaller diametered first lens cup having a first axial aperture in the end thereof; and

a second duo-diameter element telescoped within said first element having a substantially cylindrical sidewall portion separating an open end and an opposite peripherally shouldered partial closure in the form of a smaller diametered second lens cup having an axial aperture in the end thereof, said second element axial aperture being oppositely disposed to said first element axial aperture, said second element shouldered portion having a rounded exterior peripheral surface, said open end of said second element being oriented toward the inner surface of said peripheral shoulder of said first element, said second element sidewall portion having a plurality of at least three equi-spaced exterior longitudinal bosses having a minimum longitudinal length of at least half the longitudinal length of said second element sidewall portion, said bosses of said second element assuming contiguous longitudinal engagement with the inner sidewall surface of said first element to provide alignment of said apertures, the outside diameter of the open end of said second element being at least equal to the inside diameter of the cylindrical sidewall portion of said first element at substantially the half-way point of said first element sidewall portion to consummate a constrained placement en- 1 1 gagement between the two elements, the sidewall of said second element being longitudinally shorter than the sidewall of said first element, said elements being locked together by a plurality of crimps discretely spaced about the peripheral portions of the first element sidewall adjacent the open end thereof in rig-id engagement with the rounded exterior surface of the shouldered portion of said second element to provide equalized constrained concentricity UNITED STATES PATENTS 2,942,128 6/1960 Johns-0n 31382 2,963,534 12/1960 Del Camp 220-8 3,027,479 3/1962 Benway 313-82 JAMES W. LAWRENCE, Primary Examiner.

thereto thereby eonsummating desired apertural align- 10 v A RANC ta tExam' r IS n we ment of said elements.

Claims

1. IN AN ELECTRON GUN STRUCTURE OF AN ELECTRON DISCHARGE DEVICE HAVING A LONGITUDINAL AXIS, A TWO-ELEMENT DOUBLEENDED APERTURED ELECTRODE HAVING INTEGRAL ALIGNMENT MEANS COMPRISING: A FIRST ELEMENT HAVING A SUBSTANTIALLY CYLINDRICAL SIDEWALL PORTION SEPARATING AN OPEN END AND AN OPPOSING PARTIAL CLOSURE FORMED WITH AN AXIAL APERTURE THEREIN, SAID FIRST ELEMENT HAVING AN INTERIOR BEARING SURFACE; AND A SECOND ELEMENT TELESCOPED WITHIN SAID FIRST ELEMENT HAVING A SUBSTANTIALLY CYLINDRICAL SIDEWALL PORTION SEPARATING AN OPEN END AND AN OPPOSING PARTIAL CLOSURE FORMED WITH AN AXIAL APERTURE THEREIN, SAID SECOND ELEMENT AXIAL APERTURE BEING OPPOSITELY DISPOSED TO SAID FIRST ELEMENT AXIAL APERTURE, SAID SECOND ELEMENT CLOSURE HAVING AN EXTERIOR PERIPHERAL SURFACE, THE OUTSIDE DIAMETER OF SAID SECOND ELEMENT SIDEWALL PORTION BEING DIAMETRICALLY SMALLER THAN THE INSIDE DIAMETER OF SAID FIRST ELEMENT SIDEWALL PORTION TO PROVIDE COMPATIBLE CONTIGUITY THEREWITH, SAID SIDEWALL OF SAID SECOND ELEMENT HAVING BEARING MEANS TO ENGAGE SAID BEARING SURFACE OF SAID FIRST ELEMENT TO PROVIDE CONSTRAINED PLACEMENT OF SAID ELEMENTS AND ALIGNMENT OF SAID APERTURES THEREIN, THE SIDEWALL OF SAID SECOND ELEMENT BEING LONGITUDINALLY SHORTER THAN THE SIDEWALL OF SAID FIRST ELEMENT, SAID ELEMENTS BEING LOCKED TOGETHER BY A PLURALITY OF CRIMPS DISCRETELY SPACED AND SIMULTANEOUSLY APPLIED ABOUT THE PERIPHERAL PORTIONS OF THE FIRST ELEMENT SIDEWALL ADJACENT THE OPEN END THEREOF IN RIGID ENGAGEMENT WITH THE EXTERIOR PERIPHERAL SURFACE OF THE CLOSURE PORTION OF SAID SECOND ELEMENT TO PROVIDE EQUALIZED CONSTRAINED CONCENTRICITY THERETO THEREBY CONSUMMATING DESIRED APERTURAL ALIGNMENT OF SAID ELEMENTS.