US2323140A

US2323140A - Mount support and contact for electron discharge devices

Info

Publication number: US2323140A
Application number: US440902A
Authority: US
Inventors: Jr Clifford H Lane
Original assignee: RCA Corp
Current assignee: RCA Corp
Priority date: 1942-04-29
Filing date: 1942-04-29
Publication date: 1943-06-29
Anticipated expiration: 1960-06-29

Description

June 29, 1943. c, H. LANE, JR 2,323,140

MOUNT SUPPORT AND CONTACT FOR ELECTRON DISCHARGE DEVICES Filed April 29, 1942 I l V I '26 i l l I I l t 2 Q16 I I I: 24 I 2 1 24 6 i 1 1 l s ii 4 11; l l 14 l4 HI ATTORNEY NVENTOR. Clifford Lane, Jr;

I Patented June 29, 1943 UNITED MOUNT SUPPORT AND CONTACT FOR ELECTRON DISCHARGE DEVICES Clifford H. Lane, Jn, Brooklyn, N. Y., assignor to Radio Corporation of America, a corporation of Delaware Application April 29, 1942, Serial No. 440,902

9 Claims.

My invention relates to electron discharge devices particularly of the cathode ray type and to electrode supporting and electrical contact means for such devices.

- In many electron discharge devices there is provided a coating of electrically conductive ma terial usually applied to the inner surface of the envelope wall. While it is possible to provide contact with this coating, such as by a lead sealed into and extending through the envelope wall, such a construction is expensive and often subject to failure due to vibrational effects and other causes. While it has been proposed to provide resilient metal fingers contacting the inner wall coating and simultaneously supporting the electrode structure against lateral movement, such arrangements are not altogether satisfactory in that the high compression of such spring fingers against the wall coating during assembly often strips the coating from the envelope wall so that in an assembled position these spring fingers make poor electrical contact with the coating.

j, It is an object of my invention to provide resilient contacts between electrode structures in electron discharge devices which will not become defective during use. It is another object to provide a resilient electrical contact which may be moved into contact-making position with an electrically conductive coating without damage to the. coating. It is a further object to provide a resilient support for an electrode structure in combination with a resilient electrical contact audit isa ,still further object of my invention to provide improved supporting means for an electrode assembly that is easy to assemble,

rugged in construction, inexpensive to manufacture and which at the same time provides good electrical contact with an electrically conductive wall coating. In accordance with my invention I provide resilient members ailixed to a transverse support on the electrode mount assembly, preferscription and the accompanying drawing wherein- Figure 1 is a full scale longitudinal view of an electrode mount structure incorporating my invention and suitable for use in a cathode ray tube;

Figure 2 shows a cathode ray tube incorporating the mount structure of Figure 1;

Figure 3 shows a combined mount support and electrical contact made in accordance with my invention, and

Figure 4 is a plan View of the support and contact shown in Figure 3.

While I will describe my invention with particular reference to its application in cathode ray tubes, it will be appreciated that it is never theless equally applicable to other electron discharge devices where a combined electrode support and electrical contact means is desired. Referring to Figure l I have shown in actual size an electrode mount structure I comprising conventional electron gun electrodes merely as an example of a structure which it is desired to support within an envelope, the structure comprising a conventional centrally apertured grid electrode 2 enclosing the usual cathode and heater, not shown, a cylindrical anode 4 and a plurality of apertured anode discs 6, 8 and II). The electrodes 2 and 4 are supported on a stem or press [2 by insulating "rods [4, the disc electrode/5 being supported from the anode cylinder 4 by direct contact therewith, the anode discs 8 and I!) being in turn supported fromthe anode disc 5 by tubular insulators l6 which likewise may support two pairs of

deflection plates

18 and 20 as well known in the art. M

In accordance with my invention I provide a transverse member supported by the mount structure I such as the anode disc Ill and afiix thereto a plurality of resilient mount support members which have integrally formed contact making springs or such springs attached thereto, and I so construct the mount supports and contacts that in an unstressed condition the contacts will not impede the entry of the mount structure into the tubular portion of an envelope. More particularly in accordance with my invention I provide a plurality of resilient mount supports or spacers 22 afiixed to a transverse member such as the anode disc l0 and I attach or form integrally with each spacer a contact member '24 such that with the spacer 22 in an unstressed condition thefree ends of the members '24 are closer together than the free ends of the mount spacers 22, the purpose of this feature being apparent from an inspection of Figure 2.

Referring to Figure 2 which shows a cathode ray tube incorporating the structure of my invention and the mount structure shown in Figure 1, I have shown the tube as including an envelope 28 having a tubular portion 25 enclosing the electrode mount structure I, only a portion of which is shown. In such tubes it is desirable to provide an internal envelope wall coating, such as a coating 30 of aquadag or other electrically conductive material. During assembling of the mount structure shown in Figure 1, the open end of the tubular portion 26 of the envelope is slipped over the mount structure, as shown by the two arrows in Figure 1. It is very desirable, particularly in automatic assembling and sealing of the tubular portion 20 to the stem or press 12, to obviate any manual or automatic means to contract portions of the mount structure to allow the envelope tubular portion to slip over the mount. The free ends of the contact members 24 in an unstressed position, that is prior to the assembly with the envelope, are relatively close together and trans versely separted by a distance, less than the internal diameter of the neck portion 26. Similarly the resilient mount spacers 22 are so formed that the free ends are separated by a transverse distance greater than the internal diameter of the neck portion 26. Consequently as shown in Figure 1 the envelope may be slipped over the mount structure without interference from the free ends of the contact members 24 and as the envelope is slipped over the mount, it compresses the mount spacers 22 forcing them inwardly about a fulcrum point on the anode disc i0, and compressing them against the wall of the envelope neck portion as shown in Figure 2. Simultaneously the free ends of the contact members 24 are forced outwardly into contact with the internal wall coating 30 and resiliently held against this wall coating by compressional forces exerted by the neck portion 26 through the mount support members 22. Thus the end of the short mount spacer acts as a fulcrum when the free ends are subjected to a bending moment thereby decreasing the radius of curvature of the spacer 22 and increasing the radius of curvature of the contact member 24.

, To provide adequate support, the mount Spacers 22 may be of relatively heavy flat metal strip and may bear 0n the neck portion with relatively heavy pressure. In the structures shown in Figures 1 and 2 I have found a pressure of twelve ounces adequate to properly support the mount when using four mount spacers 22 equally distributed around the transverse support such as the anode disc Ill, only two of which are provided with the contact-making However, in accordance with my nickel-20% chromium alloy for the metal strip material.

It will be appreciated that instead of using two separated strips of metal for forming the mount spacers and contact members, that a single strip of metal may be utilized. Referring to Figures 3 and 4- I have shown such a combined spacer and contact comprising a spacer portion 32 and a contact portion 34 supported on a transverse member such as the anode disc lll. While this arrangement practically requires the use of a uniform thickness metal strip, I have found that satisfactory results may be obtained without exerting too much pressure at the electrical point of contact with the wall coating 30, while still maintaining sufficient compression against the tubular portion of the envelope to provide adequate mount support. In forming the combined spacer and contact member shown in Figures 3 and 4, it is particularly necessary to provide a relatively large area of contact between the spacer portion '32 and the contact portion 34 such as over an area 36 so that the pressure exerted by the envelope wall does not tend to deflect the free end of the contact portion 34 away from the conductive coating 33. Thus, as the portion 32 is compressed inwardly toward the mount axis in the direction of the arrow 38, it is necessary that the contact portion 34 move outwardly at its free end as shown by the direction of the arrow Ail, Figure 3. To provide smooth engagement between the conductive coating 30 and the contact member as the mount is slipped into the neck portion, I prefer to emboss or rib the contact area of the contact member as shown at 42 and such embossing or ribbing may likewise be provided at the opposite end as shown at 44.

While I have described only two specific embodiments of my invention, and have described their use in tubes of the cathode ray type, it will be appreciated that various other modifications may be made and various other uses contemplated without departing from the scope of my invention as set forth in the appended claims.

I claim: a

1. An electron discharge device comprising an envelope having a tubular portion, an electrode supporting structure within said'tubular portion, a transverse member on said structure, and a resilient envelope spacer supported by said member and contacting two longitudinally separated points along the said envelope tubular portion, said spacer being spaced from said tubular portion between said points of contact.

2. An electron discharge device comprising an envelope having a tubular portion, an electrode mount structure extending within said tubular Consequently I provide the strip material of metal portion, an electrically conductive coating covering a section of said tubular portion, a transverse member on said structure, and an electrically conductiVe resilient mount spacer supported by said member and held in compression by said envelope portion at two longitudinally separated points along said envelope tubular portion, said spacer making electrical contact with said coating at one of said points of contact.

3. An electron discharge device comprising an envelope having a tubular portion, aninternal electrically conductive coating over a section of said tubular portion, an electrode mount structure within said tubular portion, a transverse member supported by said mount structure,

an electrically conducting envelope spacer supported by said transverse member, said spacer contacting said tubular portion and said conductive coating on opposite sides of said transverse member, the point of contact with said conductive coating being more remote from said transverse member than the point of contact with said tubular portion.

4. An electron discharge device comprising an envelope having a tubular portion, an internal electrically conductive coating over asection of said tubular portion, an electrode mount structure within said tubular portion, a transverse member supported by said mount structure, an electrically conducting member including a mount spacer portion supported by said transverse member extending longitudinally of said envelope portion and a contact portion supported by said spacer portion on one side longitudinally of said transverse member and extending longitudinally of said envelope and making electrical contact with said conductive coating on the opposite side longitudinally of said transverse member.

5. An electron discharge device comprising an envelope having a tubular portion, an electrode mount assembly axially supported within said envelope tubular portion, a conductive coating over a section of said tubular portion, said coating extending within close proximity of said mount assembly, a transverse member on said mount assembly and a plurality of resilient mount spacers supported by said transverse member each of which is in resilient compressive contact at opposite ends thereof and on opposite sides of said transverse member with said conductive coating and said tubular portion, the compression acting at opposite ends of said spacers being such that when said mount assembly is withdrawn from said tubular portion the ends of said spacers originally in contact with said conductive coating move closer to the longitudinal axis of said mount assembly.

6. An electron discharge device comprising an envelope having a tubular portion of predetermined diameter, an electrode mount assembly axially supported within said envelope tubular portion, a conductive coating over a section of said tubular portion, said mount assembly telescoping within said conductive coating, a transverse member on said mount assembly and oppositely disposed resilient mount spacers supported by said transverse member each of said spacers being in resilient compressive contact at opposite ends thereof with said conductive coating and said tubular portion, the compression exerted at the end of said spacers contacting said coating being less than the compression exerted at the opposite end of said spacers, the form of said spacers being such that when said mount assembly is withdrawn from said tubular portion the ends of said spacers originally in contact with said conductive coating are separated by a distance less than the internal diameter of said envelope tubular portion.

7. An electrode mount spacer and electrical contact adapted to engage separated points along a wall of an enclosing envelope comprising a resilient member having two portions of different length joined near on end and extending in one direction from said one end, the other end of the shorter portion being intermediate the ends of the longer portion and acting as a fulcrum when said shorter portion is distorted by a force adjacent the junction of said two portions.

8. An electrode mount spacer for contacting separated points along the wall of an enclosing envelope comprising a resilient member having two arced portions of difierent length joined near one end back-to-back and extending in one direction from said one end, the other ,s end of the shorter portion being intermediate the ends of the longer portion and acting as a fulcrum when said shorter portion is subjected to a force tending to decrease the radius of curvature of the shorter arced portion.

9. An electrode mount spacer for contacting separated points along the wall of an enclosing envelope comprising two resilient arced memhens of different length joined back-to-back near one of the ends thereof, the other end of the shorter member serving as a fulcrum when th said members are subjected to a bending moment applied at the said joined ends thereof.

CLIFFORD H. LANE, JR.