US2078371A - Electron discharge device - Google Patents

Description

April 27, 1937. DAENE 2,078,371

ELECTRON DISCHARGE DEVICE Filed April 19, 1955 INVENTOR HERBERT DAENE ATTORNEY Patented Apr. 27, 1937 UNITED STATES PATENT OFFICE ELECTRON DISCHARGE DEVICE many Application April 19, 1935; Serial No. 17,185v

In Germany May 11, 1934 3 Claims.

My invention relates to improvements in electron discharge tubes and more particularly to improved means for firmly and accurately positioning the electrode mount within the envelope of 5 the tube.

In the construction of electron discharge tubes, the electrodes are supported so that they can withstand mechanical stresses such as those which occur when the tubes are being shipped or subjected to vigorous jarring.

Two of the well-known arrangements which have hitherto been used are supporting the free end of the electrode system from the interior wall of the envelope of the discharge tube by 5 means of resilient or rigid metal members and supporting the free end of the electrode system from the interior wall of the envelope by rigid insulating members.

These arrangements, however, have various ob- J'ectionable characteristics. The metal parts for supporting the electrodes may become incandescent or very hot when degassing the electrode parts by means of high frequency treatment, thus causing cracks in the tube envelope where the metal parts contact the glass. If these metal supporting parts are conductively connected with electrodes connected to high voltages and large loads there is danger of the glass cracking during operation of the tube. Elastic as well as rigid metal supports have this undesirable characteristic. Insulating glass supports fused with the glass envelope are frequently used to support the electrodes. This type of construction, however, is complicated. Mica discs have also been used for the electrode support. In this last case, be-

cause of unavoidable variations in dimensions of the electron discharge tube envelopes in mass production, close contact between the glass wall of the envelope and the mica disc support is not always obtained. The result of this is that the mica disc has a certain amount of play in the envelope and therefore does not properly support the electrodes. Because of this play, movement 45 of the electrodes is possible and this movement causes variations of the electric properties of the tube, which leads to disturbing noises in any radio equipment in which the tube may be used.

The principal object of my invention is to firm- 50 ly hold and accurately position the free end of an electrode mount within the envelope of an electron discharge device by flexible means attached to the mount and firmly engaging the interior Walls of the envelope without producing a delete- 65, rious effect on the mount or on the walls of the envelope or injuring the envelope in any way during exhaust.

According to my invention, the electrodes are preferably resiliently supported by means of an insulating member, so that any vibrations occurring will not give rise to rattling or noise in the tube and will be quickly damped.

Insulating members attached to the electrode mount and contacting the interior wall of the envelope to resiliently support the mount in the envelope may be used according to my invention in the following ways: (1) An insulating disc attached to the top of the electrode assembly may be provided with long resilient teeth. Mica discs have already been used which are provided with teeth 1-2 mm. long. In this case, however, there is little if any resiliency, since the teeth abut perpendicularly on the glass wall of the envelope. The teeth should be longer to obtain a .good resilient support. (2) The insulating disc without resilient fingers may be secured to the electrode mount by means of springs. Three supporting springs, properly arranged, will provide a satisfactory support. (3) The supports may also be made by attaching insulating tips to resilient metal fingers attached to the top of the electrode mount by means of the supports described, differences in dimensions occurring in the materials in the mass production of electron discharge tube envelopes are compensated for with certainty.

For simplifying the construction, especially when large differences in the dimensions of the envelopes occur, an electron discharge device embodying applicants invention can be so made that the resilient support is effected against the inner wall of the reduced portion or dome of the envelope at the end remote from the base of the tube. By slightly varying the height of the sealing-in, in this case, even large difierences in dimensions in the discharge tube envelopes can be readily compensated for.

.The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims, but the invention itself will best be understood by reference to the following description taken in connection with the accompanying drawing, in which:

Figure l is a View in perspective of an electron discharge device embodying my invention;

Figure 2 is an enlarged plan view of the mica support shown in Figure 1;

Figure 3 shows an electron discharge device embodying a modification of the invention shown in Figure 1;

Figure 4 is an enlarged view of the details of construction of the resilient support shown in Figure 3;

Figure 5 is an enlarged end view taken along section 55 of Figure 3;

Figure 6 is a perspective View of the electron discharge device embodying my invention as shown in Figure 1 in an envelope the dimensions of which vary from that shown in Figure 1;

Figure '7 is an electron discharge device embodying a still further modification of the inven-' tion shown in Figure 1. V

In Figure l, the stem I supports the electrode mount assembly 2, having a mica disc 3 secured to the top of the mount inside the glass envelope 4. The mica disc 3, as best shown in Figure 2, is provided with three or more resilient teeth or fingers 5. These resilient teeth or fingers 5 are increased in length by cutting back into the mica disc 3, thus effectively increasing the length of the fingers and their resiliency without decreasing the diameter of the mica disc. 'These teeth or fingers contact the interior wall of the reduced portion or dome of the envelope of the tube to resiliently support the mount within the envelope.

In Figure 3 the electrode system 6 is supported at the upper end of envelope l by means of the resilient supports 9 shown in detail in Figure 4. The resilient supports consist of a free-ended resilient metal part or finger ill fixed at one end to a rod i i for example by welding and having at its free end a strip or tip l2 of mica fastened to the metal part ill for example by riveting. The metal part It provides most of the resiliency of the support. As best shown in Figures 3 and 5 the rods H are non-rotatably secured to a collar I3 which may be secured to the mica spacer 14 or to the upper ends of the plate or grid side rods. With this arrangement compensation for the variations in dimensions of the tube envelopes are provided without varying the height of the sealing-in of the mount.

In Figure 6 is shown the applicability of the embodiment of my invention shown in Figure 1 to the dome type of tube it: having an exaggerated dome portion. By placing the mount [1 further up into the envelope large variations in the dome portion of the tube envelopes can be accommodated by means of the resilient mica support it attached to the mount [1.

In Figure '7 the envelope l8 encloses an electrode mount assembly [9 having secured to the top an insulating disc 28 upon which is resiliently supported a second disc 2! by means of three spring members 22 fastened to the two micas.

The top mica rests against the inside wall of the envelope [8 to resiliently position the mount in the tube envelope.

While I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated specific applications for which my invention may be employedjit will be apparent that my invention is not limited to the exact forms illustrated or the use indicated, but that many variations may be made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

sembly positioned in said envelope and extending coaxially of the envelope, a plurality of freeended resilient metal supports each secured at one end to said mount and a rigid strip of insulating material secured to each metal support at the free end and engaging the wall of said envelope to firmly and resiliently support said mount in a predetermined position within the envelope.

2. An electron discharge device provided with an envelope having a tubular portion, a mount comprising an electrode assembly positioned in said envelope and extending within said tubular portion, a plurality of resilient free-ended metal supports each having one end connected to the mount and the other end extending within the tubular portion of the envelope and insulating members secured to the free ends of said metallic supports to engage the wall of the tubular portion of the envelope to firmly and resiliently support the mount in a predetermined position within the extended tubular portion of the envelope.

3. An electron discharge device provided with an envelope having an extended tubular portion, a mount comprising an electrode assembly positioned in said envelope and extending coaxially of and within said tubular portion, a collar secured to the upper end of the mount, a plurality of resilient metal fingers secured at one end to said collar, insulating strips secured to the other end of said metal fingers and engaging the walls of the tubular portion of the envelope to firmly and resiliently support said mount in a predetermined position within the extended tubular portion of the envelope.

HERBERT DAENE.

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