US1271245A - Seal for vapor electric apparatus. - Google Patents

Description

M. VON RECKLINGHAUSEN.

SEAL FOR VAPOR ELECTRIC APPARATUS. APPLICATION FILED JULY I2. 1913.

1 ,27 1,245. Patented July 2, 1918.

2 SHEETSSHEET I.

M. VON RECKLINGHAUSEN.

SEAL FOR VAPOR ELECTRIC APPARATUS.

APPLICAHON FILED JULY l2. I913.

1 71,245. Patented July 2,1918.

2 SHEETS- SHEET 2.

WITNESSES:

- UNITED STATES PATENT OFFICE.

m vox REGKLINGHAUSEN, OI SURESNES, FRANCE, ASSIGNOR TO COOPER HEWITT ELECTRIC COMPANY, 01' HOBOKEN, NEW JERSEY,A CORPORATION OF NEW JERSEY.

Specification of Letters Patent.

Patented July 2, 1918.

Application filed July 12, 1913. Serial No. 778,886.

To all whom it may concern:

Be it known that I, Max von Breme- HAUSEN, a subject of the Emperor of Germany, and resident of Suresnes, France, have invented certain new and useful Improvements in Seals for Vapor Electric Apparatus, of which the following is a specification.

My invention relates to the making of hermetic seals for a leading-in conductor through the walls of vessels and more particularly relates to electric seals for vessels of quartz or similar material. It has been customary to make hermetic seals between glass and some suitable metal like platinum by selecting a glam of approximately the same co'eflicient of expansion with temperature as the metal. When, however, a metal which has the same coefiicient ofexpansion as. quartz is sought, no material appears to be available which will stand the temperature necessary to fuse the quartz without being itself melted. By my invention I, however,

accomplish a hermetic seal through quartz by usmg an elastic conductor and making it of such thin section that the amount of expansion produced during the making of the seal is not sufiiciently large to overcome the resistance of the quartz and thus start a leak. Under these conditions quartz is capable of withstanding heavy unit pressures which, however, not aggregate many pounds in total. siderable number of ways of applying this principle to conducting seals. I ma use a number of metals which have a s cientl high melting 'point for this quartz sea for example platinum, molybdenum, and tungsten.

In the accompanying drawings Figures 1 and 2 are two views of a simple form-of seal; Figs. 3 and 4 show a tubular seal; Figs. 5 and 6 show a multiple strip seal; Fig. 7 shows a 'fierent strip seal; Fig. 8 shows a multi e'wire seal; Fi 9 shows a disk seal; Fig. 10 shows a doub e disk seal; and Figs. 11 and 12 illustrate methodsof manufacture.

In Fig. 1, the wall of the container is shown at 1, and the leading-in .conductor through the wall at 2, which conductor may may I ave illustrated a con?! be of platinum. This conductor extends to the right and left furnishing connections to the interior and the exterior of the vessel. This container wall may be of quartz or similar material. Near the center pf the platinum leading-in wire I have shown a flattened portion, 3, having one very thin dimension and a proportionally larger surface at right angles thereto. In view of the thmness of this flattened section the expansion transversely is not suflicient to overstrain the quartz and the expansion laterally is taken up inview of the thinness of the metal. The unflattened part of this wire, 2, cannot be relied upon to make a ti ht seal. In making this seal the wire is st flattened, its surface cleaned by fire and the quartz melted and pressed tightly upon the metal till it sticks to the surface thereof. On cooling the quartz continues to adhere to the metal and no breaking away occurs sufficient to permit the leakage of air through the seal.

In the embodiment shown in Figs. 3 and 4:, L is a thin tube of metal such as platinum and l is the Wall of the container, a certain portion of 1 being shown within the tube 4. Thetube 4 extends upward and downward as shown in Fig. 3 making connection with the electrode and the external circuit.

In this seal the walls of the tube are made so thin that the expansion and resultant stress are insuificient to cause a leak, the platinum being overwhelmed, so to speak, by the greater mass of quartz.

' This seal is constructed similarly to the I seal of Fig. 1 by pressing the quartz in a soft state firmly against the metal inside andoutside and permitting the seal to .cool when complete.

In Figs. 5 and 6, I show a different embodiment in which a number of very thin strips, 5, 5, of metal such as platinum are buried in the-quartz wall, 1. These strips, 5, are connected at the ends by plates, 6, which serve to collect and distribute current in the strips, 5. In this arrangement as in the others the strips are so thm as not to produce either expansion or stress enough to rupture the quartz or make a leaky seal. 3 Fig. 7 is a modification of Fig. 6. I may inserted extend the strips numbered 7 and constituting the seal in this case and connect them together at the ends, as shown, a certain portionof the quartz, 8, being formed up to press them into this position.

In Fig. 8 I have shown modifications somewhat similar to Fig. 5 by utilizin metal wires, 9, of very thin diameter suc as platinum wires, which wire should be connected in parallel both inside and outside the wall, 1, somewhat as in the case of Fig. 6. This seal of Fig. 8 is efi'ective for the same reason as are the others. 7

Fig. 9 is another form of seal, in which the quartz wall, 1, has an opening in it closed by a disk, 10, having very thin ed which edges are buried in the rim of t ewindow in the quartz wall. This disk, which ma be of platinum, should be connected wit the electrode on the inside by mercury or by a suitable wire and may be connected to the outside circuit either throu h an extension of the platinum disk or t rou h a conductor, 12, connected to the said isk. In this case the thin portion, which alone should be relied upon for the seal, should not be of suflicient mass to break away from the quartz.

In the manufacture of these seals it is often desirable to protect the surface of the metal from the effects of the air by doing the heating in an inert gas or in a vacuum. For example the seals shown in Fig. 7 may be made in the following manner: Pieces of quartz approximately the same width are etween four thin strips of metal which are to form the seals. Around this packet of metal and quartz may be placed additional quartz which is to form the wall of the container or a portion thereof and the whole placed in a larger quartz tube through which an inert gas 1s made to pass, the whole may then be melted from the outside by a suitable flame.

Fig. 11 shows a method of adapting a platinum disk having extremely thin edges to form a seal for a quartz mercury tube. A quartz mercury tube which is to constitute the seal chamber is softened up and the disk placed in the tube and the heavy walls of the gl1artz tube forced in upon the edges of the 'sk. If desired the. quartz may be reinforced at this point for the purpose of securing extreme mechanical strength in the quartz and giving suflicient pressure to hold the joint between the quartz and the edge of the diskvery tight. This disk is inserted in a conducting rod acting as a lead.

I in-through the wall and one or more additional seals of the same sort may be placed inthe same lead in conductor and sealed in the wall as'shown in Fig. 11 wherein 13 are the disks, 15' the reinforced walls, and 14 the tube supporting the seal.

nernaee In Fig. 10- I show the details ofclampsas which may be used for pressing the quartz on to the edge of'the disk in forming the seal. These tools may be ower operated or automatic if desired. 'Fhe clamps are shown at 16.

In Fig. 12 I show in plan view the formation of such a seal, there being two upper clamps and two lower clamps. It will be understoodthat my invention is not limited to this particular form of clamping device 16 nor to this particular shape of termmal, for the idea is capable of many' applications and I wish to claim all that is new in the arrangement shown.

In connection with the action of these so seals, so far as described, it will be understood that any (piece of quartz of good strength can stan a certain pressure or certain strain without breaking, and further the numerical amount of the expansion of 35 metal used for lead-in wires with temperature depends upon the thickness of themetal expanded. Consequently there will be a .certain thickness of metal in which the amount of expansion numerically will be below what is necessary to cause actual rupture in the quartz just referred to and my seal lies within this range. The above,'however, is put forth merely as a tentative explanation of what goes on during theconstruction and use of my seal and I do not wish to limit myself to this particular theory of operation for the result speaks for itself. I claim as my invention 1. In a seal for an evacuated container, a

-metallic conductor embedded air-tight in an insulator of quartz with an expansion coefficient practically equal to zero characterized by putting into the quartz a conductor made of a metal of higher or the same melting point as quartz, the conductor being of such cross section that the thickness of the metal in one of .the axes perpendicular to the length axis of the conductor is very small in comparison with the thickness in the other axis perpendicular to the length axis of the conductor.

2. In a seal for an evacuated container, a plurality of metallic conductors embedded gas tight in a body of quartz or similar material having an expansion coeflicient relatively small, said metallic conductors being made of material of higher melting point than said quartz or equivalent and being of such cross section that the thickness of the material in the direction of one axis perpendicular to the length axis of the conductor is very small in comparison with the thickness of the metal along the other axis perpendicular to the length axis of the conductor, and means for joining the several conductors on both sides'of the seal.

3. A seal for an evacuated container comprising a wall of quartz, a conductor leading through said quartz, said conductor having 7 a flattened portion, said quartz being sealed c to and including the natural irregular edge of saidv flattened portion.

4:. A seal for a quartz container comprising a wall of quartzand a gridiron having extremely thin strips of metal for its transverse members Whereby'the ex ansion of the 10 metal is maintained below t e safe maxi- 1 mum, said gridiron being embedded airtight in said quartz wall.

Signed at New York, in the county of New York and State of New York, this 10th day of July, A. D. 1913.

MAX VON RECKLINGHAUSEN.

-Witnesses:

WM. H. CAPEL, Tnos. H. BROWN.

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