US2588306A

US2588306A - Fracturable seal

Info

Publication number: US2588306A
Authority: US
Inventors: Jr Alfred H Taylor
Original assignee: Air Reduction Co Inc
Current assignee: Airco Inc
Priority date: 1949-06-07
Filing date: 1949-06-07
Publication date: 1952-03-04
Anticipated expiration: 1969-03-04

Description

March 4, 1952 A, H. TAYLOR, JR

FRACTURABLE SEAL 2 SHEETS--SHEET l Filed June 7, 1949 ar. lva

FIG!

xNVl-:NTOR Y ALFRED H. TAYLOR JR.

ATTORN EY5 March 4, 1952 A. H. TAY| OR, JR

FRACTURABLE SEAL 2 SllEETS--SHEET 2 Filed June 7, 1949 FIG. 6

mvEN-roR ALFRED H. TAYLOIR JR.

FIG. 8

M, n n; @M

ATTORNEYS Patented Mar. 4, 1952 FRACTURABLE SEAL Alfred H. Taylor, Jr., Tuckahoe, N. Y., assignor to Air Reduction Company, Incorporated, a corporation of New York Application June 7, 1949, Serial No. 97,531

(Cl. Z22-541) 17 Claims.

This invention relates to hermetic seals and more particularly to fracturable hermetic seals for fluid-filled containers.

One application of this invention is in the packaging and dispensing of the rare gases of the atmosphere, i. e., argon, helium, neon, xenon, and krypton. These gases are produced and packaged in a very pure state for use in industry, one such use being in the electric lighting and sign-making industry, for `the manufacture of so-called neon signs. One of the primary requirements in the handling of these gases is that they be kep absolutely pure and uncontaminated.

Current practice is to store or ship the puried gas after sealing it in a chemically clean evacuated glass flask or container of the break seal type, the break seal being most commonly formed by drawing it from the glass of the flask or container itself or from the glass of a glass exit tube previously sealed to the glass flask or container. The break seal, whether drawn from the flask itself or from an exit tube, is surrounded by a glass delivery tube fused to the flask. To dispense the gas from such a flask or container, a weight is placed in the delivery tube above the break seal, and the head of the delivery tube is then hermetically sealed to the gas receiving apparatus. Following this, the receiving apparatus is evacuated and then, either by means of a magnet or by gravity, the weight is caused to fall on the break seal, break it oli, and permit delivery of the gas from the flask to the receiving apparatus. Apparatus of this type, however, as will be readily apparent, is particularly fragile and requires fairly careful construction. The rigors of transportation, unless the flasks or containers are very carefully and, therefore, usually expensively packed, frequently result in breakage of the glass delivery tube or sometimes even of the break seals themselves.

In some cases delivery tubes of rubber or like material have been used with some degree of success. However, there are certain disadvantages in the use of non-metallic flexible delivery tubes. For example, they are more often than not too flexible and too easily deformable and therefore permit deformation during shipment and consequent breakage of the break seal. Also, it is difficult to truly hermetically seal such tubes to either the flasks or containers or to the receiving apparatus, when such tubes are subject to both positive and negative pressure with respect to the surrounding atmosphere. Additionally, rubber and, as far as I know, all other equivalent materials contain volatile plasticizers that contaminate gases of the above type with which they come into contact. This, of course, cannot be tolerated and thus delivery tubes of rubber or like material cannot' be satisfactorily used with containers in which such gases are to be stored and shipped, and for which the fracturable seals of this invention have been primarily designed. Such tubes, because of their flexibility, tend also to collapse When positive evacuation of the flask or container is employed.

Heretofore, storage and shipping flasks or con tainers, particularly for rare gases, have been made of glass primarily because closures of the above set forth break seal type have been applicable only to them.` Recently, however, the use of metal containers has been initiated. While Y fracturable seals of the prior art are not suitable for use with metal containers, those contemplated by this invention are and, additionally, may still be applied to conventional glass flasks with considerable advantage.

The primary object of this invention is to pro- `vide a form of fracturable seal that is more durfracturable seal that may be applied to either glass or metal flasks and containers and to glass or metal delivery tubes or other receiving apparatus. y

An additional object of the invention is to provide a fracturable seal which is deformable to break a fracturable sealing member contained therein, but which is not so easily deformable or so flexible that the sealing member may be accidently broken during transportation of al container to which the fracturable seal is secured.

According to this invention, the fracturable seal comprises a tube-like member or conduit, a portion at least of which is made of a glass-sealing metallic alloy, which may be hermetically sealed ,to either metallic or glass-like articles. Substantially within the tube-like conduit is disposed a fracturable member of glass, porcelain or the like which is hermetically sealed to a portion of the conduit made of the glass-sealing metallic alloy to prevent the passage of uid through the conduit. It is contemplated that the fracturable seal so formed be premanently secured to the flask or container and to a delivery tube which may subsequently be hermetically sealed to a receiving apparatus. However, it should here be understood, of course, that the fracturable seal itself may be used for other purposes. In the contemplated use of the seal conduit member thereof is desirable, be made of metal.

tube I3. delivery tube I3 may'be hermetically sealed to a ,tube directly thereto. 4is then evacuated and sealed pff. To'release the adapted to be hermetically sealed to both the container and the delivery tube, either one of which may be made of glass or metal. That portion of the conduit which is to be hermetically sealed to glass is a portion which is made of the glasssealing metallic alloy, while that portion which is to be hermetically sealed to metal may be either a portion which is made of the glass-sealing metallic alloy or a portion made of an ordinary metal or metal alloy, in the latter case it being contemplated that the portion be made of a yieldable metal or metal alloy somewhat softer and more pliable than the glass-sealing metallic alloy.

Further objects and advantages of the fracturable seals of this invention will be apparent from the following specic description and drawings of a number of different forms thereof.

In the drawings:

Figs. l and 2 show one type of fracturable seal applied to metal and glass containers respectively,

Fig. 3 is an enlarged sectional View of the fracturable seal shown in'Figs. 1 and 2,

, Figs. 4 and 5 are enlarged sectional views showing modified forms of the type of fractur- `ableseal shown in Figs. 1 and 2,

Fig. 6 illustrates a fracturable seal of a somewhat diierent type applied to a metal container, Fig. 7 illustrates a fracturable seal of the same general type as that shown in Fig.v 6 applied to a glass container,

Fig. 8 is an enlarged sectional view of the seal of Fig. 6, and

Fig. 9 is an enlarged sectional view of the seal of Fig. '7. Y y

Referring to Figs. 1 and 2, there are illustrated fluid containers Ill and II made respectively of metal and glass. For the purposes of this description and because it is contemplated that the improved fracturable seal is to be used primarily with containers for rare gases, the containers I and II will be referred to as gas containers. As

'the gas containers may contain gas under pressure, the container I0 of Fig. l is illustrated as having concave ends. Each container is provided with a fracturable seal I2, which is hermetically sealed thereto. At the other end of the fracturable seal, in each case, is shown a glass delivery tube I3 hermetically sealed to the fracturable seal. The delivery tube I3 may, if For the sake of clarity, 4the fracturable seals I2 are illustrated lconsiderably larger with respect to the size of their respective containers than is normally the case.

Various forms which the fracturable seal shown'inFigs. 1 and 2 may take are shown in enlarged section in Figs. 35. Each comprises a metal tube I having disposed substantially within it a fracturable member IB made of glass, porcelain, or the like. The fracturable member of the seal shown in Fig. 3 is a small glass tube sealed closed at one end and inserted substantial- .ly-concentrically within metal tube I5, its open send'being hermetically sealed to one end of the metal tube. Thus, gas is prevented from passing through'tube l5. The tube 'I5 itself is hermetically sealed at one end as by soldering to the end of a metal container I0. At the other end tube I5 is hermetically sealed to a glass delivery To use the gas in the container, the

receiving apparatus usually by fusing the glass The receiving apparatus 4 gas from the container metal tube I5 is deformed either by hand or with the aid of a toOl to break the fracturable member I6.

Since the metal tube I5 is to have sealed thereto a glass, porcelain, or the like fracturable member I6 and is itself hermetically sealed to either metal or glass, it is essential that it be made of material of very special properties. As well as having to be capable of being hermetically sealed to either glass or metal, it must also be pliable or malleable so that it can be deformed to effect the fracture of the fracturable member. Metals possessing these characteristics are available and are known as glass sealing alloys.

, Different glass-sealing alloys are adapted for use with different types of glass. One such alloy that has. been found particularly useful with lead glass is Sylvania alloy No. 4, a high chrome steel in which the chrome oxides, produced by heating the alloy, bond to both steel and glass to effect the desired hermetic seal. This alloy is, additionally, soft enough t0 permit a tube I5 made of it to be deformed by hand with a little dilculty or by means of a tool, such as a pair of pliers, with ease. It may also, of course, be readily soldered to a metal container` end wall. A commercial alloy known as Kovar is capable of making a seal with hard glass. There are several other glass-sealing alloys known to the trade, all of which may be used with one or another type of glass, and all of which are contemplated as being within the scope of this invention. Oxygen-free high conductivity copper can also be included in the general classification of glass-sealing alloys, although it is relatively expensive and sealing it to the glass is more difcult than is the sealing to glass of the true glass-sealing alloys.

The fracturable seals of Figs. 4 and 5 are similar to that of Fig. 3 described above, except for the shape of the fracturable member IS. In Fig. 4 the fracturable seal is tube-like but is not as long. as that shown in Fig. 3 and terminates in a bulbular portion Il. The seal in this case has been shown connecting a glass container II to a glass delivery tube I3. The fracturable member I6, shown in Fig. 5, is in the form of a glass bead sealed into a necked down portion I8 of metal tube I5. It may be broken by deformation of the tube at the necked down portion I'I thereof.

The fracturable seals above described each comprise but two parts, a tubular member I5 made of a glass-sealing alloy, and a fracturable member I6 made of glass, porcelain, or the like secured thereto. While such tubular members I5 may be deformed by hand to break the fracturable member disposed therein, such deformation without the use of tools is rather difficult. In most cases Athis is an advantage, however, because it minimizes the opportunities for accidental fracture of the seal. Nevertheless, it may be desirable in some cases to use a softer and more pliable outer tube which may be deformed manually with ease. Annealed copper has, among other soft materials, been found to be very satisfactory for this use. But since the copper cannot be sealed directly to glass, a piece of glass-sealing alloy must be interposed between the glass and the copper at each point where such' a union is required. Fracturable seals of this type, that is, those having a portion of their tubular outer members formed of .a soft'metal, easily deformable by hand, are disclosed in Figs. 6-9, Fig. 6 showing one type'20 of ysuch a seal Secured to a'metal container 2l and a glass'de- -soldering to container 2|. 4portion of the fracturable seal so formed may `be manually deformed, with ease, to break the livery tube 22, and Fig. 7 showing another type 23 of such a seal secured to a glass container 24 and metal delivery tube 25.

The fracturable seal 2Q, shown in Fig. 6, is illustrated in enlarged section in Fig. 8 and comprises a tubular member, a portion 26 of which is made of a glass-sealing alloy, and the remainder 21 of which is made of soft pliable metal such as annealed copper, these portions being hermetically sealed to one another as by soldering. Substantially concentrically disposed therein is a glass, porcelain, or the like fracturable member 28, being tubular in shape and closed at one end and open at the other. The open end thereof is hermetically sealed to glass-sealing alloy portion 25 of the outer tubular member and the closed end extends into the soft pliable metal portion thereof. rIhe glass-sealing alloy portion of the fracturable seal is itself hermetically sealed to the glass delivery tube 22, and the soft copper portion 21 thereof is hermetically sealed as by The soft metallic fracturable member 23 contained therein, thereby permitting the ow of gas through the seal.

A somewhat modified form of the latter type of fracturable seal is shown in Fig. 7 and in enlarged section in Fig. 9, this form being designed for use with a glass container and a metal delivery tube. The fracturable seal comprises an outer tube made up of two glass-sealing alloy portions 30 and 3|, joined together by a tubular member 32 made of a soft pliable metal such as annealed copper, and a fracturable member 33, tube-like in shape and having an open end and a closed end, the open end being hermetically sealed to one of the glass-sealing alloy portions of the outer tubing. The fracturable member is of such. length that it extends into the soft pliable metallic portion of the outer tubing. One of the glass-sealing alloy portions of the tubing is hermetically sealed as by soldering to the metal delivery tube and the other is hermetically sealed to the glass container. This type of fracturable seal may be readily and easily deformed by hand at its portion made of soft pliable metal to break the fracturable member.

While in the majority of the above types and forms Vof fracturable seal described, the fracturablemember is hermetically sealed to the tubular outer member of the fracturable seal at `the end thereof which is connected to the delivery tube, it is, of' course, clear that in most ,cases it might be as readily sealed to the other end.

I claim:

l. A fracturable seal which comprises a tubelike conduit a portion at least of which is made oi' a glass-sealing metallic alloy, and a fracturable member disposed substantially within said conduit and hermetically sealed to a portion of the conduit made of glass-sealing metallic alloy, said fracturable member normally preventing the passage of fluid through said conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture the fracturable member.

2. A fracturable seal as set forth in claim l in which the fracturable member is made of glass.

3. A fracturable seal as set forth in claim 1 in which the fracturable member is made of porcelain.

4. A fracturable seal which comprises a tubelike conduit a portion at least of which is made of a glass-sealing metallic alloy and a fracturable member having an open and a closed end, said fracturable member being disposed substantially within said conduit and having its open end hermetically sealed to said portion of the conduit to prevent the passage of iluid through said conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture the fracturable member.

5. A fracturable sealwhich comprises a tube- `like conduit a portion of which is made of a glasssealing metallic alloy and a second portion of which is made of a more pliable metal, and a fracturable member hermetically sealed. to a p0rtion of the conduit made of glass-sealing metallic alloy, said fracturable member normally preventing the passage of fluid through the conduit and extending into the portion of the conduit made of the more pliable metal.

6. A fracturable seal which comprises a tubelike conduit the endl portions of which are made of a glass-sealing metallic alloy and the central portion of which is made of a more pliable metal, and a fracturable member disposed substantially Within said conduit and hermetically sealed to one of the portions of the conduit made of the glass-sealing metallic alloy and extending into the portion of the conduit made of the more pliable metal, said fracturable member normally preventing the passage of fluid through said conduit.

'7. The combination with a fluid container and a delivery tube of a fracturable seal permanently connecting the delivery tube to the fluid container, the fracturable seal comprising a tubelike conduit which is hermetically sealed at one end to the delivery tube and at the other end to a part of the container, a portion at least of said conduit being made of a glass-sealing metallic alloy, and a fracturable member disposed substantially within-said conduit and hermetically sealed to said portion of the conduit made of glass-sealing metallic alloy, said fracturable member normally preventing passage of fluid through said conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture the fracturable member.

8. A fracturable seal as set forth in claim 7 in which the fracturable member is made of glass.

9. A fracturable seal as set forth in claim 7 in which the fracturable seal is made of porcelain.

10. A fracturable seal permanently connecting two members, one of said members consisting of a delivery tube and the other consisting of a fluid container and one of said members being made of glass, the fracturable seal comprising a tubelike conduit which is hermetically sealed at one end to the delivery tube and at the other end to a part of the container, that portion at least of said conduit which is hermetically sealed to the member made of glass being made of a glasssealing metallic alloy, and a fracturable member disposed substantially within said conduit and hermetically sealed to a portion of the conduit made of glass-sealing metallic alloy, said fracturable member normally preventing the passage oi fluid through said conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture the fracturable member.

11. A fracturable seal permanently connecting .tivo members, one of Said members `consisting of a delivery tube and the other consisting of a ,fluid container kand one of said members being made of metal, the fracturable seal comprising a tubelike conduit which is hermetically sealed at one end to the delivery tube and at the other end to a part of the container, a portion vat least of said conduit being made of a glass-sealing metallic alloy, and a fracturable member disposed substantially within said conduit and hermetically sealed to a portion of the conduit made of glass.- sealing metallic alloy, said fracturabe member normally preventing the passage of fluid through ysaid conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture tbe fracturable member- 12. The combination with a glass duid con.- tainer Iand a glass delivery tube o f a fracturable seal permanently connecting the delivery tube to the fluid container, the fracturable seal comprising a tube-like conduit which is hermetically sealed at one end to the delivery tube and at the other end to a part of the container, the end portions at least of said tube-like conduit being made of a glass-sealing metallic alloy, and a fracturable member disposed substantially Within said conduit and hermetically sealed to a portion of the conduit made of glass-sealing metallic alloy, said fracturable member normally preventing passage of fluid through said conduit, and a portion of the conduit adjacent the fracturable member being pliable so that such portion may be deformed to rupture the fracturable member.

13. A fracturable seal as set forth in claim 12 in which the fracturable member is made of glass.

14. The combination with a fluid container and a delivery tube of a fracturable seal permanently connecting the delivery tube to the fluid container, the fracturable seal comprising a tubelike conduit made of a glass-sealing metallic alloy hermetically sealed at one end to the delivery tube and hermetically sealed at the other end to a part of the container, and a fracturable member disposed substantially within `said conduit and hermetically sealed to the conduit, said fracturable member normally preventing passage of fluid through said conduit, and said conduit being pliable so that it may be deformed to rupture the fracturable member.

15. The combination with a iiuid container and a delivery tube of a fracturable seal permanently connecting the delivery tube to the fluid container, the fracturable seal comprising a tubellike conduit one portion of which is made of ta glass-sealing metallic alloy and a secondV portion of which is madeof a more pliable metal, said tube-like conduit being hermetically sealed at one end to the delivery tube and at the other end .to a part of the container, and a fracturable member disposed substantially within said conduit and hermetically sealed to a portion of the conduit made of glass-sealing metallic alloy, said fracturable member normally lpreventing the passage of uid through the conduit and Vextending into the portion of the conduit made of the more pliable metal.

16. A fracturable seal permanently connecting two members, one of said members consisting of a delivery tube and the other consisting of a fluid container and one of said members being made of glass and the other being made of metaL, the fracturable seal comprising a tube.- like conduit hermetically sealed at one end to the delivery tube and at the other end to .the contaner, that portion of said tube-like conduit Whichis hermetically sealed to the vglass member being made of a glass-sealing metallic alloy and that portion of the tube-like conduit which is hermetically sealed to the metal member beingmade of a softer and more pliable metal, and a fracturable member disposed substantially Within said conduit and hermetically sealed to the portion thereof made of glass-sealing metallic alloy, said fracturable member normally preventing the passage of fluid through the conduit and extending into the portion of the conduit made of the softer and more pliable metal.

17. A fracturable seal which comprises a tribelike conduit made of a glass-sealing metallic alloy, and a fracturable member disposed substantially Within said conduit and hermetically sealed to the conduit, said fracturable member normally preventing passage of fluid through said conduit, and said conduit being pliable so that it may be deformed to rupture the fracturable members.

ALFRED TAYLOR, JR.

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

UNITED STATES PATENTS Number Name. Date 785,176 Mommertz Mar. 21, 1905 2,006,226 Yaxley June 25, 1935 2,225,220 Huff Dec. I7, 1940 2,370,870 McKeague Mar. 6, `1945 2,464,487 Chappell et al. Mar. 15, 1949