Патент USA US2408238код для вставки
m4@ P. L. SPENCER MAGNETRON CASING Filed Dec. 17, 1941 f 2,408,235 ' Patented Sept. 24, 1946 ` y * 2,408,236 UNITED _sT-Aras Percy y , L. i, Spencer, ' MAcrNE'raoNfcasind West Newton, Masts., c „ Raytheon Manufacturing‘v Company, Newton; Mass.,'a corporation of Delaware’ . i ‘c comms. (c1. 25p-¿gral This invention relates to amagnetron casing, and more particularly to such aA casing ’which is made of a metal, such as copper, and is provided with a special end construction `to increase `the effective magnetic iield within the magnetron, t `In magnetron tubes of the conductive envelope type, themagnetic ñel'd is impressed ori the'tubes by magnetic poles placed adjacentbthe‘opposite ends of thetube. Thus there _is an leffective air gap'between the poles extendi?igl‘tiie entire length calme-magnetron“ ,The 'metallic ’wallsI of the envelope must> -'necessarily be of a certain thick ness in order to possess the requisite rigidity to An .additional lead >'I3 may be provided to ex tend from' a'fs'uitalble'coupling means within the envelope >~I', ,wherebyÁ high frequency oscillation generated within the device may be conducted to a suitable utilization device. ¿The lead I3 may likewise be sealed throughÍ the 'outer end of a glass.l chamber- Ilmounted at theL oute'd end of the> pipe ,I5 'likewise hermetically »sealed within the walls of [the envelope l. The magnetron is designed and‘intendedto be placed between suit fable1~mag'ne'tic „p'o'le’sï I6.Y andy I_f'lto create a longi tudinal vmagneticl ‘ñeld " passing- through the space between the cathode B and the surrounding walls of the bore 5, constituting [the anode structure withstand the differential atmospheric pressure cathode. inside and outside of the tube. This length kof 15 forIf said the end caps 2 and 3 were made entirely of air gap makes it difficult to produce magnetic copper, it will be seen that the air gap between fields of the desired highintensity in the dis the poles I6 and I1 would extend the entire charge space within the magnetron. length ofthe envelope I. Since it is desired to An object of this invention is to devise a mag crearte high intensities ofy magnetic ñelds within netron casing in which the effective air gap length 20 the discharge space around the cathode 6, the between the magnetic poles is substantially de presence of a relatively long air gap makes it dif creased. ficult to set up fields of the desired intensity. Another object is to produce such a structure’ Thus any way in which the length of this air _in which the reduction in air gap is accomplished gap can be decreased will greatly increase the by the use of highly magnetic end caps provided 25 effectiveness of the magnetron device. However, with means whereby these caps may be readily secured in place as by soldering. The foregoing and other objects of this inven tion will be best understood from the following . . as already indicaited, it is> necessary that the wall thickness of the end caps 2 and 3 be a substan til value in order to withstand the atmospheric exerted upon them. One way in which description of an exempliiication thereof, refer 30 pressure the air gap might be decreased would be to make ence being had to the accompanying drawing, the end caps entirely of a magnetic material, such wherein: ' Fig. 1 is a vertical cross-section through a as iron. However, if the end caps were made ' entirely of iron, serious difficulties would arise magnetron incorporating my invention, taken in attempting to hermetically seal the iron'end along line I-I of Fig. 2; and 35 caps to the copper walls of the envelope I. In Fig. 2 is a top view of the magnetron as illus accordance with my invention, the end caps, for example the upper cap 2, is made of a thin copper sheet I8 formed into a cup shape fitting relative velope I which is preferably made of a block snugly within the open upper end of theeh of non-magnetic conductive material, such as 40 ly velope I. A plate 20 of a magnetic material, such copper. This block forms the anode of the mag as iron, is fitted into the upper open end of the netron, and is provided with hollow end sections cup thus formed. The plate >20 may be fastened which are covered by end caps 2 and 3„likewise within the cup in any suitable way, as by solder of conductive material. Between the hollow end ing, so as to form a composite wall of the re sections of the envelope I is the central bridging 45 quisifte physical strength. However, it is not portion II. The portion 4 is provided with a cen necessary to have the connection between the tral bore 5 within which is supported substan iron plate 20 and the copper sheet I8 in any way tially at the center thereof a cathode 6, prefer hermetic inasmuch as the copper plate I8 in it ably of the indirectly-heated oxide-coated therm selfforms an imperforate and impermeable wall 50 ionic type. The cathode 6 is supported by a pair against the passage of atmospheric gases into the 1 of cathode lead-in conductors 'l and 8 sealed device. The plate I8 may be sealed-to the wall through the ends of glass chambers 9 and I0 on -of the envelope I along the joint 22 in some suit trated in Fig. 1. Y Y The magnetron illustrated comprises an en the outer ends of pipes II and I_2 hermetically fastened within the walls of the envelope I ad able way, as by silver solder. This _method of jacent the upper and lowerl hollow end sections. 55 sealing two copper members together so as to 2,408,236 3 4 form a hermetic seal has been very satisfactory and effective. In a particular embodiment I have made` the sheet i8 of a copper sheet .015 of an inch lthick, While the plate 2d could be of a sub sealed to and closing one end of said hollow en velope, said end cap comprising a sheet of a sub stantially non-magnetic metal and an insert of stantially greater thickness, for example one magnetic material set into said sheet to decrease the gap space through which said magnetic ñeld eighth of an inch. The end cap 3 is made iden tical with that of ythe end cap l2, yand comprises must pass. a copper sheet `lil With a magnetic insert 2 I. Of course it is to be understood that this inven tion is not limited to the particular details of construction as described above as many equiva-v composed substantially of copper and containing cooperating electrode elements, said magnetron lents will suggest themselves to those skilled in the art. For example, instead of having the magnetic plates extend across substantially> the entire end of the magnetron, they could be `of'a more limited extent so as to concentrate th'e 2. A magnetron comprising anhollow envelope j being designed and adapted to have a magnetic Yiield set up in the space between said electrode elements, said envelope having an end cap sealed ¿to and closing one end of said hollow envelope, _ AsaidY end` cap comprising a sheet of copper and an insert ¿of magnetic material set into said >sheet to ädecrease the gap space through which' said ~ magnetic-ñeldmust pass. magnetic ñeld in the device 'more nearly along_31. A magnetron comprising a hollow envelope the central bore â, where the greatest concentra composed substantially of copper and containing tion of the field is desired. Also the principles of this invention might be applied to various 20 cooperating electrode elements, said magnetron other types of devices utilizing the magnetic iield being designed and adapted to 'have a magnetic in which the size of the envelope plays a sub ñeld VSet` up inthe space between said electrode stantial part in limiting the magnetic field by elements, >>said envelope having an end cap sealed introducing a substantial airgap. ` to' andY _closing one end of said hollow envelope, What is claimed is: Y. said end _cap comprising a sheet _of copper and 1. A magnetron comprising a hollow envelope an insert of magnetic material set >into said sheet of a substantially non-magnetic metal contain to decrease the gap space through which said ing cooperating electrode elements, said magne magnetic ñeld _must pass, said sealing being made tron being designed and adapted to have a mag between the copper part of said end cap and th neticiield set _up in the space between said elec 30 ,copper of `said envelope. ' trode elements,„said envelope h'aving an end cap ' ' ' PERCY L. SPENCER.