US2909689A

US2909689A - Support strap for electron gun structures

Info

Publication number: US2909689A
Application number: US533622A
Authority: US
Inventors: George L Case
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1955-09-12
Filing date: 1955-09-12
Publication date: 1959-10-20
Anticipated expiration: 1976-10-20
Also published as: GB812577A

Description

Oct. 20, 1959 G. L. cAsE 2,909,689.

SUPPORT STRAP FOR ELECTRON GUN STRUCTURES I med sept. 12, 1955 una aan 'annua volunvannnnvluuv mvaauvn nur@ graan vara INVENTOR: GEORGE L. CASE.,

ATTO EY K v United Sfar@ r1f,lff11f 0 SUPPORT STRAP FOR ELECTRON GUN ,y

STRUCTURES George L. Case, Phoenix, N.Y., a'ssgnor to 'General 'ElectricvCompany, a corporation of New York Applicati'n september l12, 1951s, sin-itu` No. 533,622 s claims.l (ci. 31a-sz) trode elements, aflixed to said element, and having' terminal portions adaptedy to be secured to the support rods.

Prior known arrangements have proposed to insert the straps attached to the electrode elements into glass support rodsy thus securing said elements. Each vstrap is generallylformed; 'with a semi-cylindrical body portion adapted to be fitted. to each cylindrical electrode element and yhaving lateral portions which are in diametrically opposed relation. Thev terminal portions of the strap which are inserted .into Vthe molten glass material arevmerely straight extensionsrof the lateral portions. Because the lateral and terminalportions Y, are on opposing ends of a straight-line it has heretofore been found necessaryvto accomplish the embedding process sequentially, lor alternatively to maintain the electrode elements stationary while cradles containing the molten glass are brought into contact with the terminal portions. Usual practice has been to attach the straps to the individual electrode elements by spot welding. The ends of the straps are Vthen embedded in the support rods positioning the individualelements in spaced` relation. A conventional method of embedding each of the straps into the rods, or beading, as thisV means of anchoring the straps is termed,`cons ists in placing the entire unit ofvelectrode elements in a jig Vand moving the jig such thatcommon ends ofthe attached straps are inserted into asupport rod whilethe latter is in a molten state, and then' allowing the rod tolcool; thereby anchoring the straps in the rod.l The unit is. next withdrawn, rotated, and theother common ends of the straps Vare inserted vintoftheir respective rod. This latter rod is Yallowed to c ool,l and the unit is withdrawn., The vsteps are repeated if Aadditional supporting members are to be/beaded.` The just-described methodfhas an inherent disadvantage in that, the beading operations are neces- Asarily performed sequentially. Hence, the operation is "1 time consuming andrthus costly. A second disadvantage is that axial misalignment results, unless extreme care is exercised ldueto the uns'yinmetrical heatingand cooling of the straps and .of the lsupport rods.` In guns having multiple axesr a third disadvantage is that tilting ofthe axes'of the electrode elements with respect y"to each other mayy re'sultfdue also to thejunsymmetrical heating and c.ooling. W l Another conventional method'fo embedding the .straps Lin .the rods consists in moving-.the beading .material into ,5;

l Patented Oct. 20, 1.959

. 2 v contact Withthe ends of the straps While the electrode elements are held stationary. Because the various cradles holding the molten glass must be moved into contact with the end portions of the straps, the machine employed to perform the operation is complicated, unwieldy, and expensive. Y i l v 4 Accordingly, it a principal` object of my invention to provide a new andl improved supportstrap lfor a cathode ray tube gun structure that is expeditiouslyV and eciently ,airixedtothe support rods resulting, in c onsiderable cost and time saving in the manufacture of such structure. f

Another object of my invention is to provide a new and improved support strap that ,accurately maintains the electrodevelements in predetermined axial alignment.

Another object of my invention is Y to provide a new and improved support strap that permits simultaneous beading. f

'Further 'objects and vadvantages of my inventionzwill becomeV apparent from Athe following description and the featuresof novelty which characterize my invention will be pointed out with particularity in the claims annexed ytoA and forming part of this specification.. y

In carrying out the objects of my-invention I provide a novel strap support for use in'electron gun structures for cathode ray tubes, said strap supports ,having termif nal portions disposed in'thesame general direction from a common plane such'that beadingof all terminal portions can be'accomplished simply, elciently, and simultaneously.

For a detailed explanation of my invention, reference is made to the accompanying drawings in .which Figure l 'is a'n'elevational view of a catho-defraytube gun structure embodying features of lmy inventing'- Figure 2 is an isometric view of lthe lower` portion of taken along the line I'n'Figu're l, an electronvgunfis showii'located/'in neck portion 11.of a cathode' `ray',y tube'envelope;'said electron gun comprising a cathode-control' grid electrode assembly 12, a number two onscreen grid 13, an anode orv number., Sygrid 14, and a'mag'netic focusing means generally 'indicated' at 15.l Each of the preceding ele ments or assemblies may be ofaiiy suitableconve'ntional design and' for purposes well known'A to those 'skilled `in the art. Since the cathode element vis not, pe'r se, a part of the invention 'it'is included' in thevdra'wing g'env erally as`A part of 'electrode :assembly 12.-" Lead wires connecting the elements 12,'13, and 14 'to the closed end of the neck portion 11 are'not' shownsince the arrangements thereforey and lthe' 'manner of connection For maintaining the electrode elements, 12, 13, and 14 in spaced alignment one or more insulative glass rods or

beads

17, 18 are provided in adjacent spaced relation to said elements. As shown more clearly in Figure 2, the cathode-control grid assembly 12, the screen grid 13, and the anode 14 are connected to the

glass beads

17, 18 by means of support or beading

straps

21, 22, 23, and 24 respectively, constructed and arranged in accordance with the preferred embodiment of the present invention. The beading

straps

21, 22, 23 and 24 may be similarly constructed and may be *formed generally, as shown clearly in Figure 4, of any suitable materials and in any suitable manner as by bending or stamping to provide; a semicylindrical body portion 25, lateral portions 26 which extend from the chordally opposed ends of the body portion 2S, and terminal portions 27 which are bent to define an angle with said lateral portions 26.

The terminal portions 27 are formed such as to extend in the same direction and substantially parallel to one another. In the preferred embodiment shown clearly in Figures 2 and 4, the terminal portions 27 are formed at approximately right angles to the cop1anar lateral portions 26. By this construction, the apexes 28 of the terminal portions 27, are inserted perpendicularly into the

molten glass beads

17 and 18, thus effecting little distortion of the

beads

17 and 18. This allows the molten glass to ow quickly and evenly to embed each of the terminal portions 27, anchoring them securely to the

respective beads

17 and 18. The terminal portions 27 must be of sufficient length to provide a good anchoring surface. I have found for best results that the terminal portions 27 should preferably project into the

beads

17 and 18 approximately 1/9 as a minimum. It is desirable that the apexes 28 be inserted into the bead material by a force which is parallel to the terminal positions 27, thus placing less tension on each strap as it is inserted into the bead material and consequently minimizing the possibility of axial misalignment.

In assembly, the

straps

21, 22', 23, and 24 are initially aixed to the

individual electrode elements

12, 13, and 14 as by spot welding. Due to the special construction all of the terminal portions 27 of the

straps

21, 22, 23, and 24 project in the same general direction. In the interest of practical manufacturing techniques the terminal portions 27 are aixed so as to project downward. The

electrode elements

12, 13, and 14 with the respectively aixed

straps

21, 22, 23, and 24 are placed in a jig to hold

elements

12, 13 and 14 in fixed spaced relation. Cradles adapted to hold the

glass beads

17 and 18 are disposed in spaced relation beneath the straps. After a bead of glass is melted in the cradles the jig is moved toward the cradles, simultaneously forcing all the apexes 2S of the terminal portions 27 into the molten glass. The glass is allowed to cool thereby anchoring the

straps

21, 22, 23, and 24, and the now fixedly spaced electrode elements are withdrawn.

With relation to a common chordal plane through each of the

cylindrical electrode elements

12, 13, and 14, each strap is tted on that same side of the cylinder as the terminal portions extend, as indicated in Figure 3. This construction is preferred since as the terminal portions l27 of each strap is forced into the

molten beads

17, and 18, each strap is pressed against the electrode element to which it is attached and no tension is placed on the spot welds, and a minimum tension is placed on the

straps

21, 22, 23, and 24. If the strap is fitted on the opposite side of the cylindrical element as shown in Figure the force exerted on each strap is also placed on the spot welds necessitating that the welds and the straps be of stronger construction. Although the first design is preferred, the second design has been successfully employed.

If additional supports are required, strap members may be placed in circumferential spaced relation as for' example in Figure 6. By this construction, a support member 31 may Abe simply a straight extension designed to extend in the same direction as the terminal portions 27 of the associated straps. Likewise, extra support members can be added to the embodiment shown in Figure 5; the terminal portions of each additional support member being formed to extend in the same direction.

It will be understood that the body portion 25 need not conform to the contour of the associated electrode element, the lateral portions then being connected directly to spaced points on the associated electrode element as by spot welding.

Also, it will be understood that such `lateral portions may be formed integrally with the associated electrode element as for example by striking out portions of the cylinder wall to form such lateral portions.

It will further be understood that while glass beads or rods where described hereinabove, rods of other insulative material can be similarly employed such as quartz, mica, ceramic or the like as a base for anchoring the electrode elements of the gun structure.

Although the present invention has been illustrated by specific examples, it will be obvious to those skilled in the art that modifications may be made without departing from the spirit thereof.

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

l. A strap for supporting an electrode in an electron discharge device comprising a body portion adapted to be secured to the electrode, arm portions attached to said body portion and extending outward from said body portion in opposite directions, a terminal portion on each respective arm portion adapted to be embedded in respective heat-softenable support rod, all of said terminal portions extending in the same direction whereby through displacement of said strap in said same direction all of said terminal portions can be embedded simultaneously.

2. A strap for supporting a cylindrical electrode between a plurality of heat-softenable supports in an electron discharge device comprising a body portion having a cylindrical curvature adapted to complement the electrode, and a plurality of terminal portions spaced according to the spacing of said supports and each adapted to be embedded in a respective support, all of said terminal portions extending toward their distal ends in substantially the same direction as that in which the convex surface of said body portion faces, whereby through displacement of said strap in said common direction relative to said supports all of said terminal portions can be embedded simultaneously.

3. In an electron discharge device, an electrode, a plurality of heat softenable spaced support members between' which the electrode is located, respective connectors secured to said electrode opposite said respective support members and having terminal portions remote from said electrode embedded in said respective support members, said terminal portions all extending toward their extremities in a common direction to enable simultaneous embedding thereotf by simultaneous displacement of said terminal portions in said common direction relative to said support members.

4. In an electron discharge device, an electrode, a plurality of spaced support rods of heat-softenable material, strap means attached to said electrode for supporting said electrode from said rods, said strap means having arm portions extending laterally outwardly from said electrode in opposite directions, and a terminal portion on each arm portion embedded in a respective support rod, said terminal portions extending in the same direction and approximately perpendicular to the plane of said arm portions. Y

5. In an electron discharge device, a cylindrical electrode, a plurality of spaced support members of heatsoftenable material, a support strap for said electrode, said strap having a semi-cylindrical body portion to the concave surface of which said electrode is attached, arm portions extending outwardly from said body portion,

and a terminal portion on each arm portion embedded in a respective support member, said terminal portions eX- tending toward their distal ends in substantially the same direction as that in which the convex surface of said body portion faces, whereby said terminal portions may 5 be embedded simultaneously by simultaneous displacement thereof relative to said support members in said same direction.

References Cited in the ile of this patent UNITED STATES PATENTS Teal May 30, Koch et a1. Oct. 28, Szegho Aug. 28, Szegho Oct. 30, Mutter May 20, Giacchetti May 12,