US2358668A

US2358668A - X-ray tube anode seal

Info

Publication number: US2358668A
Application number: US428358A
Authority: US
Inventors: Nelson H Stewart
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1942-01-27
Filing date: 1942-01-27
Publication date: 1944-09-19
Anticipated expiration: 1961-09-19

Description

p 19, 1944. N; STEWART 2,358,668

- X-RAY TUBE ANODE SEAL Filed Jan. 27, 1942 INVENTOR W mum ATTORNEY Patented Sept. 19, 1944 I STATES TUBE ANoDE SEAL.

Nelson Hist wart; Caldwell, N.' J, 'assfignorfftol r WestinghousejElectric &Manufa,ctuifingCom-" T j may, East Pittsburgh, rag-a, corporation bit Pen'n'sylvania Application llanuary 27, maseriaifnb.42 8,33

3 Claims. (01. 25o 1 49 This invention relatesto'the fabrication of an.

anode for an X-jray. tube, especially to .such

7 anodes which'include a copper rod supportinga press element or: the alloy; known as Kovar or like metal capable of being readily united to the glass of the press, and the invention relates more particularly to the joint between the copper rod and the Kovar and the method of forming such union.

In the usual type of copper anode using a Kovar seal, the Kovar is soldered to the anode afterthe anode has been machined. In addition to the fact that some losses are experienced due to poor soldering, the latter constitutes an extra operation which can be avoided, thus cheapening the manufacturing costs of an anode, according to the results attending my researches in this field.

Accordingly, an object of this invention is'to avoid the disadvantages and inconveniences incidental to the use of asoldered joint between the Kovar element and its copper support by eliminating the use of solder in that connection.

Another object is to cutv down the number of operations in forming the aforesaid joint by uniting the Kovar to the copper at the same time that the copper is cast.

A further object is to provide means to produce the cast Kovar-copper joint in such a manner that the cast product can be readily machined to a shape which facilitates the step of sealing the Kovar element into the glass press by which the anode 'is' eventually integrated with the X-ray tube.

Still another object is to provide apparatus 1 which can be used over and over for the fabrication, seriatim, inquantity production, of anodes made according to the present invention, each of the anodes constituting a complete anode unit as an intermediate product ready for incorporation in its X-ray tube by the use of substantially conventional machinery.

. duced being capable of being stored, transported and supplied in desired quantities as such.

Other objects and features of the invention will be made apparent to those skilled in the art as progress is made with the description of the embodiment of the invention selected for illustration in the accompanying drawing wherein:

, part designated by the reference character H is a copper rod which in the instance shown is to .gree of heat applied, the copper slug l0 melts and flows down and around vthetarget H3 in Fig. 1 is a view inside elevation, partly in sec tion, of an anode mien x raytubain the construcfon of wlriich the present invention' has'be'en embodied Fig. 2 s

assemutortiiacampaneet lin'iits ferment: the anode of Fig. 1 and including the crucible in which said assembly is placed ready for subjection tothe heat of a suitable furnace;

Fig. 3 is a view in sectional elevation, illustrating the assembly of Fig. 2 disposed within the furnace, and showing the parts in their position after application of the necessary heat Fig. 4 shows the anode removed from the furnace and crucible and partly machined.

Referring now to the drawing in detaiL-the constitute the body of the anode in the completed product, the latter being shown in Fig. 1, while in Fig. 2 the copper element is indicated as a slug at l0, being as yet unshaped.

On top of the copper slug I0 is then placed a carbon bushing l5, which serves to hold in place the Kovar element l 6, the latter taking the form of a thimble with a lip l'l. Within this thimble is placed a weight l8 made of metal having a melte ing point higher than that of copper, and having 7 a mass adequate to overcome the buoyancy of the Kovar thimble and accordingly acting to sink it into the copper when the latter is in its melted state, as indicated at C in Fig. 3.

In operation, when the assembly of Fig. 2 has been placed in the furnace l9 and a suitable deknown fashion, and the weight l8 draws the thimble [6 down into the molten copper and at.

the same time draws the lip I! of the thimble against the top of the carbon bushing until stopped by engagement of the bottom of the bushing with the upper surface of the molten copper, at which time all of the parts occupy the position shown in Fig. 3. I r

The crucible I2 and its associated parts may be removed from the furnace l9, and after allowing the copper to solidify, the partly completed anode will be removed from the crucible, when it presents the appearance shown in Fig. 4, according to which it is clear that I have formed a sturdy cast joint between the copper rod H and the Kovar seal l6 at the same operation as that of casting the copper, thus eliminating the previously required step of soldering the seal-forming thimble to the copper rod.

After turning off ,the lip I! of the thimble IS,

the carbon bushing I5,may be slid oif the Kovar thimble and can be used as many times as its condition permits, together with the carbon block I3 I and the crucible l2, these being permanent parts of my novel apparatus. The anode i now ready p to be machined in known fashion, thetop edge of the thimble libeing preferably tapered, as indicated at 2| in Fig. 1, where it enters the glass press press 22 to form the Kovar seal in known manner. The anode illustrated in Fig 1 is a complete article of manufacture, ready for its intended use in an X-ray tube, and is a unit capable of being stored with other like units, transported as such, and installed at will. p I claim:

1. An anode unit for an X-ray tube comprising a copper supporting rod, acylindrical Kovar metal seal element having oneof its peripheraledges for said tube. v

3. A complete anode unit for an X-ray tube, comprising a copper supporting rod having cast 'cast in said copper supporting rod to embed the in one end thereof a Kovar metal seal element in the form of a thimble, the closed end of said thimble being cast in the copper rod to form a molecular union therebetween; and the open end of said thimble being embedded in the glass press for said tube, the other end ofjsaid copper rod being bevelled and having cast therein a refractory metal target.

' 1 NELSON H. STEWART. j