US2565991A - Support for electron discharge devices - Google Patents

Description

Aug. 28, 1951 G. -M N. ROSE, JR 2,565,991

SUPPORT FOR ELECTRON DISCHARGE DEVICES Filed Dec. 28, 1948 INVENTOR GEORGE McNEILL ROSE R h mw Patented Aug. 28, 195i SUPPORT FOR ELECTRON DISCHARGE DEVICES George McNeil] Rose, Jr., East Orange, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application December 28, 1948, Serial No. 67,648

.16 Claims. (01. 250-36) The present invention relates to supports for electron discharge devices and more particularly to a support and contact member engaging a flat contact extending through the envelope of such devices.

Certain types of ultra high frequency electron discharge devices comprise a structure including cylindrical end portions, each serving as the lead to an electrode within the device, and a disc sealed across the envelope of the device intermediate its ends for supporting another electrode and serving as a low impedance lead therefor. Devices of this type may be used in lumped or open line circuits, or in cavity type circuits.

Several problems arise in connection with the use of a device of the type referred to in either of the lumped or cavity type circuits mentioned. One problem concerns the requirement for an adequate mechanical support for the device. Such support is required to be mechanically firm and positive without applying damaging mechanical forces to the device. The support should therefore have the characteristics of a cushion. The problem of providing a support that is both firm and cushioning is aggravated by the irregular exterior contour of a device of the type under consideration resulting from the use of a disc lead sealed through the walls of the envelope thereof.

Special problems are presented where the device is used in cavity type oscillator circuits with the grid supported on the disc lead and the cathode and anode leads taken from opposite ends of the device and serving as inputs and outputs therefor.

To sustain the oscillations in a system of this type it is usually necessary to provide for feedback from the anode or output resonator to the cathode or input resonator. If the grid disc lead is supported so that its periphery engages the inner walls of the cavity, failure of energy transfer from the anode circuit to the cathode circuit results, so that operation of the oscillator is seriously impaired. Hence, the support of the device should be accomplished in such a manner so as not to substantially impair the feedback coupling between the input and output elements of the oscillator.

Another special problem arising in the use of a disc seal type of electron discharge device in a cavity type oscillator is that of securing appropriate alignment of the device with contact members on coaxial transmission lines. Usually the end leads of the device serving the cathode and anode, respectively, are received exteriorly of the device by tubular contact members forming part of a transmission line, which are sometimes improperly aligned with respect to each other and the cavity member. This misalignment may occur either prior to mounting a device in the cavity or after the oscillator is fully assembled. If the engagement between the device and the cavity member is rigid and the contact members referred to are misaligned, harmful strains may be set up in the device which may fracture it. It is therefore desirable that the device be supported in a sufficiently rigid, yet resilient, manner in the cavity.

Accordingly, it is the object of the invention to provide an improved support for engaging an electron discharge device employing an annular lead and contact.

Another object is to provide an improved support for a disc seal type of electron discharge device.

It is a further object to provide a combined support and electrical coupling member for a disc seal type of electron discharge device having improved support and coupling characteristics.

Another object is to provide a support structure for engaging the disc of a disc seal type of electron discharge device wherein the engagement between the support and the disc is mechanically positive and resilient and provides a desired type of electrical contact between the disc and the support.

A further object is to provide a support for an electron discharge device mounted in a cavity resonator for providing oscillations, wherein said support permits feedback coupling between the output and input elements of the device.

Another object is to provide a support and coupling structure intermediate a disc type of electrode lead of an electron discharge device and a circuit element wherein the support and coupling structure engages the lead in a positive mechanical manner against displacement and provides line contacts with the circuit element for improved electrical coupling between portions of said element for providing desired feedback between input and output electrodes of said device.

A further object is to provide a support for a disc seal type of electron discharge device that combines many advantages or features in that it is relatively simple in structure, contributes to ease in mounting a device thereon, positively engages a portion of the device for firmly yet yieldingly supporting the same, and provides a desired type of electrical coupling in special applications of the device.

Further objects and advantages will become evident as the description continues.

While the invention is pointed out with par- LAJU ticularity in the appended claims, it may be best understood by the following description of embodiments thereof taken in connection with the appended drawing in which:

Figure 1 shows a type of electron discharge device with which my novel support may be used;

Figure 2 shows a perspective view of my novel support element;

Figure 3 depicts a fiat blank from which my support is formed;

Figure 4 shows my novel support element engaging an electron tube that may be used in an open circuit;

Figure 5 is a cross section along the lines 5-5 of Figure 4 and shows more clearly the manner in which my novel support engages a disc lead of an electron discharge device;

Figure 6 shows my support employed for supporting an electron discharge device in a cavity type of circuit; and,

Figure 7 depicts a section along the lines 'I--'I of Figure 6 and indicates the engagement between my support and an electron discharge device and between my support and the inner wall of a cavity.

Referring now in more detail to the drawing, there is shown in Figure 1 an ultra high frequency electron discharge device of the disc seal type with which my novel support element is suited for use. The device shown is a triode having a cathode In supported on cathode lead I I.

and anode I2 supported on anode lead I3, and a grid I4 supported on grid lead I5. The envelope of the device includes glass beads I6 and I1 and flanges I8 and I9 provided on adjacent ends of the cathode and anode leads II and I3.

The grid lead I5 is in the form of a metal disc sealed through the envelope walls formed by the glass beads I6 and I! and is provided with a central aperture I5a shown in Figure 5 within which grid I4 is supported. The grid lead I5 extends appreciably beyond the side walls of the device as a result of which the device is given an irregular shape.

Heretofore electron discharge devices of this type have been supported by transmission lines engaging the anode and cathode leads I I and I3, but no adequate support has been available for the intermediate portion of the device where most of its weight is concentrated and where accordingly a support is needed most. In some instances, in an attempt to secure the desired support, the perimeter of the disc support for the grid has been disposed in contact with the outer member of a resonant line, but such contact has interfered with proper operation of the resonant system, particularly as concerns an effective feedback coupling between the input and output elements of the system where the system comprises a cavity type oscillator, and has resulted in harmful strains in the device when the transmission lines and the outer member of the resonant line are out of alignment.

According to the invention a novel and effective support is provided for the disc extending from an intermediate portion of a disc seal type of electron discharge device that preserves the device against strains and also results in a minimum impairment of an appropriate feedback coupling when the device is employed in a cavity type oscillator. My novel support comprises a polygonal structure 20, made of some elastic metal such as Phosphor bronze, beryllium copper or spring steel, punched out as shown in Figure 2 to provide slots 2 I, which are slightly wider than the thickness of the disc lead I5. The overall di mensions of the support element are such that the element fits snugly around the disc lead I5 with a portion of the disc entering the slots 2| as shown in Figures 4 and 5. While the structure of my novel support element is shown as comprising a polygon having eight sides, my invention is not limited to a structure having this particular number of sides. Indeed, my support may have a larger or smaller number of sides than eight, and all the sides need not be fiat, subject to the limitations to be described herein. In addition to having a critical width, the slots 2I are also provided with a critical length. This length is such that the shorter edges of the slots bear against the periphery of disc I5 in line contacts when an electron discharge device is mounted on the support 20 as shown in Figures 4 and 5. The exterior corners 24 on my support structure, shown in Figs. 2 and 5, engage a further support 23 shown in Figs. 4 and 5, which may be a circuit element. This engagement it will be noted is also in line contacts. The line contacts represent an advantageous form of electrical coupling of my support with the disc lead I5 and also in certain applications with the further support 23. For example, where the further support is a cavity 25, shown in Figs. 6 and 7, the novel engagement of my support 20 with cavity is particularly advantageous as will appear more fully herein in the description of the use of my support in a cavity type oscillator.

My novel support is stamped from sheet metal strip stock 22 shown in Figure 3 and the slots 2| are provided therein at predetermined longitudinal locations therein. The strip stock is then out to predetermined length to provide a strip having a sufficient length for the formation thereof into a polygonal structure shown in Figure 2. The polygonal structure is formed by using a suitable forming tool, not shown, having the desired polygonal shape. The ends of the structure are preferably formed to include a portion of a slot 2| resulting in an open ended slot at each end of the structure for engaging the disc l5.

The electron discharge device is mounted on my novel support by spreading the support at the ends thereof so that it is permitted to embrace the periphery of the disc I5, and to receive a portion of the periphery in the slots 2|. The elasticity of the material of which the support 20 is made permits a temporary expansion of the structure without exceeding its elastic limit for the mounting of the electron discharge device thereon and results in a firm yet cushioned engagement of the disc I5 by the support.

It will thus be noted that my novel support is economical to make because of its unitary structure and the relatively small amount of stock material required in its fabrication. In addition, it permits the mounting of an electron discharge device thereon to be relatively easily accomplished. Furthermore, it firmly engages an electron discharge device supported thereby in line contacts and is designed to maintain this engagement as a result of the elasticity of the material constituting it, and also engages a further support or circuit element in line contacts.

Other advantages of my novel support will become evident from the following descriptions of two applications thereof.

One application of my novel support is in connection with the use of a disc seal type of electron discharge device in lumped or open line cirouits. Such use is shown in Figures 4 and 5. In

this application no support is provided for the cathode and anode leads II and I3 and my novel support structure advantageously serves as the sole support of the device by engaging the disc l thereon as explained before herein. As shown in Figures 4 and 5, my support 20 engages the periphery of disc l5, and a ring support 23 which may be a circuit element engages the outer corners 24 formed on my suport 20. A firm yet cushioned engagement between my support 20 and the disc l5 and between the support 20 and the ring support 23 results. It will be noted that in this application the periphery of the disc l5 does not engage the ring support 23 but that a space is provided between these elements, which space is bridged by the corner portions of my novel support element for providing a cushioned and firm intermediate body between the ring support 23 and the disc l5. While a ring type of supplementary support 23 has been shown for engaging my novel support element in an application involving an open line circuit, the supplementary support may take any other suitable form that circumstances may require.

Another application of my novel support is in connection with a cavity type circuit utilizing a cavity 25 as shown in Figures 6 and 7. My support element is particularly advantageous in this application. Not only does it firmly and at the same time in a cushioning manner support the intermediate portion of a disc seal type of electron discharge device in the cavity in much the same manner as it does in the open line circuit application previously referred to, but the polygonal structure of my support element and the slots therein, provide the required type contacts between the support 20 and the disc I 5 as well as between the support 20 and the cavity 25. In cavity type oscillator circuits, such as are shown in Figures 6 and '7, provision is often needed for electrical feedback to sustain the oscillations. This feedback occurs between portions of the cavity 25, on opposite sides of disc 15. Feedback energy must therefore traverse the region of the cavity 25 adjacent the support 20. If the support 20 engages the cavity in an uninterrupted contact the energy in one end portion of the cavity is shielded from the energy in the other end portion thereof. My novel support element contacts the grid disc and the cavity 25 only in line engagements as previously mentioned and therefore provides paths between the engagements for feedback from one end portion of the cavity to the other end portion thereof. The line engagement between the disc [5 and my support is provided by the corners formed on the shorter edges of the slots 2| in my support, which corners engage the periphery of the disc [5 in sharp line contacts. The line engagement between the support and the cavity is provided by the outer corners 24 formed between the sides of the polygonal structure of my support element.

The amount of the feedback referred to is determined by the number of sides provided in my polygonal shaped support and also by its width. Thus feedback coupling is magnified by decreasing the number of sides on my support and narrowing the width thereof. The coupling is decreased by increasing the number of sides on my support and widening the strip of which it is made. Thus, the degree of feedback coupling may be controlled to obtain a desired coupling by properly designing the support with a critical number of sides and a predetermined width. I have found a support structure having eight sides and a width of about 6 provides a firm yet cushioned support and results in a desired feedback coupling in the cavity type oscillator circuit in which it is employed.

It will be appreciated therefore that I have provided a novel support element for a disc seal type of electron discharge device which combines the features of cushioned mechanical support and in addition when the device is used in cavity circuits, provides a convenient means for controlling the feedback coupling. The elasticity of the material of my support element causes it to deform slightly against tension when an electron discharge device is mounted thereon so that pressure is exerted against both the disc on the electron discharge device which it engages as well as on the inner walls of a cavity or other member with which it is desired to associate the device. This elasticity of my novel support in addition relieves strain resulting from misaligned circuit elements. It is within the purview of the invention to so choose the dimensions of the support element that an electron discharge device is very firmly held in position with a minimum of radial pressure. With the dimensions thereof properly chosen for a particular use the combined support and coupling structure of the invention contributes substantially to good operation of the system in which it is used.

Various modifications may be made in the invention without departing from its spirit and scope as pointed out in the appended claims.

I claim:

1. An electgi ca l gontact member for a disc comprising a structiire h'aving a plurality of sides, at least one of said sides having a slot therein for receiving a portion of said disc, said structure being under tension when said disc is received thereby and means engaging said contact member for further support of said disc.

2. A support for a disc in a tubular structure comprising a polygonal member made of a material yieldably resistant to deformation of said structure, said member having flat sides and relatively sharp corners, said fiat sides having slots therein for receiving edge portions of said disc, and said corners adapted to engage the inner wall of said tubular structure.

3. A support for a disc seal type of electron discharge device comprising a metallic ribbon bent to form a tubular structure having a plurality of sides with the wider surfaces of said ribbon extending parallel to the axis of said tubular structure, one of said sides having a slot therein for receiving a portion of a disc sealed across said device for supporting said device.

4. A support for a flanged type of electron discharge device comprising a sheet metal member having slots for receiving edged portions of the flange on said device, said sheet metal member being bent to form outer corners, and means engaging said outer corners for providing a firm cushioned support for said device.

5. A support for a disc seal type of electron discharge device comprising a one-piece sheet metal structure having a plurality of straight sides and bends forming corners, said straight sides having slots therein for receiving edge portions of a disc sealed across the envelope of said device, an additonal support member, the outer corners of said first-mentioned support engaging said additional support member whereby said device is supported in a cushioned and adequately firm manner on said additional support member.

6. A support for a disc seal type of electron ing a fixed support member and a cushioning. member, said cushioning member having apertures for receiving spaced portions of said projection, said fixed support engaging spaced portions of said cushioning member, said spaced portions of said projection being angularly ofiset with respect to the spaced portions of said cushioning member, whereby a free space is provided along all radial lines from the center of said annular projection, between said fixed support and said projection for firmly supporting said device and protecting it from shocks. 7 8. A cushioned support for an electron discharge device comprising an inner member and anouter member, said inner member having slotted planar portions engaging said device said planar portions being angularly disposed with respect to each other to form ridges, said ridges being spaced from said device, said outer member being spaced from said slotted planar portions and contacting said ridges, whereby said support provides a free space in all radial directions from the center of said device and between said device and said outer member for effectively protecting said device against shocks. 9. A cavity type oscillatg ingluding an electro discharge devi'cejeftubular cavity, and means for supporting said device in said cavity, said means comprising a structure made of sheet metal and havinga predetermined number of slotted planar sides for receiving portions of said device in line contacts and outer corners formed by adjacent planar sides for engaging the inner walls of said cavity in line contacts, whereby said device is supported in a firm and cushioned manner in,

said cavity and a desired mutual coupling between the input and output elements of said.

oscillator is provided.

10. In a cavity type oscillator including a flanged electromiscfiargdevice-and a tubular cavityymeans for supporting said devicein said cavity and providing a feedback coupling between input and output elements of said oscillator, comprising a polygonal structure made of sheet metal and having slots for receiving portions of the flange on said device, and outer corners for engaging inner walls of said cavity in line contacts, whereby an effective electrical coupling between spaced portions of said cavity is provided for required feedback to sustain oscillations in said oscillator, and said device is effectively supported in a cushioned manner in said cavity.

11. A support member for an electron disbetween said support member and a portion of said device is provided, said structure being formed with the ends of said elongated sheet metal strip free and meeting to form one side of said structure whereby said support member is expandable for the mounting thereon of said device and said ends are supported on said device.

12. A contact member for supporting an electron discharge device between two energy zones in a cylindrical cavity, and having a plurality of sides joined in bends, the outer corners of said bends; lying in a circular array having a diameter to cause said corners to snugly engage the inner wall of said cavity, whereby a portion of said contact member is displaced from said inner wall, to

ermit energy transfer between said zones.

13. A cavity type oscillator including a tubular cavity, an electron discharge device having a cathode, anode and grid, leads for said cathode and anode extending through end portions of said cavity for providing oscillating energy zones therein, a lead for said grid extending from said electron discharge, device intermediate said end portions, and means for supporting said grid lead on the inner wall of said cavity, said means engaging said wall in spaced line contacts extending parallel to the axis of said cavity, whereby passageways are provided by said means and said inner wall of said cavity between said energy zone for feedback coupling between said zones.

14. A cavity resonator comprising a first device for supporting and contacting a second device, said second device having a flat annular contact member, said first device including a tubular member, and a contact device supported within said tubular member and in contact therewith, said contact devicecomprising a ribbon-like conductor having fiat sides, said flat sides having slots for receiving the edges of said fiat annular contact member.

.15. A cavity resonator comprising a first device for supporting and contacting a second device, said second device having a flat contact member extending around the periphery thereof, said first device including a tubular member, and a contact device supported Within said tubular member and in contact therewith, said contact device comprising a strip-like conductor having fiat sides, said flat sides having slots for receiving the edges of said flat contact member.

16. A cavity resonator comprising a first device for supporting and contacting a second device, said second device having a fiat contact member extending around the periphery thereof, said first device including a tubular member, and a contact device supported within said tubular member, said contact device comprising a ribbon-like conductor having slots therein for receiving the edges of said fiat contact member and longitudinal portions between said slots, said contact device at said longitudinal portions thereof being spaced from said fiat contact member and in contact with said tubular member.

GEORGE MCNEILL ROSE, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,268,567 Hamm June 4, 1918 1; 2,408,355. Turner Sept. 24, 1946 112,462,866 Hotine Mar. 1, 1949

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