US1118812A - Production of gas-tight seals or closures between metal and vitreous materials. - Google Patents

Description

PRODUCTION OF GAS TIGHT H. J. S. SAND & F. REYNOLDS.

SEALS 0R CLOSURES BETWEEN METAL A'i-i'D VITRBOUS MATERIAL.

APPLICATION FILED JAN.30,191-:.

Patented Nov. 24, 1914.

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. perfect contact under varyin tcharacter can be employed to UNITED STATES PATENT OFFICE.

HENRY JULIUS SALOMON SAND, 0F NOTTINGHAM, AND FREDERICK REYNOLDS, OF LONDON, ENGLAND.

PRODUCTION or GAS-TIGHT SEALS 03-;QLOSURES iin'rwnmr METAL AND vrmnous MATERIAL.

Application filed January 30, 1914. Serial No.

To all 'whom it may concern:

Be it known that we, HENRY JULIUS SALO- MON SAND, Ph. D., D. So. P., residing at the University College, Nottingham, England, and FREDERICK REYNOLDS, of 9 Firs Mansions, Muswell Hill, London, England, both subjects of-the King of Great Britain, have invented new and useful Improvements in the Production of Gas-Tight Seals or Closures Between Metal and Vitreous Material, of which the following is a specification.

'e have found that a clean surface of lead, or other metal, or alloy, of a similar produce a gastight seal, or closure, between itself and clean vitreous material, such, for example, as lead-glass, soda-glass, quartz-glass, and the like, when the clean metallic and vitreous surfaces are caused to adhere so closely to gether that the plasticity of the metal is sufficient to enable the two surfaces to remain in conditions as to temperature notwithstanding the change of dimensions of the metal and the glass brought about by their different degrees of expansion and contraction under changes of temperature.

We can obtain the lead, or like metal, or alloy, in a clean condition by melting it under non-oxidizing conditions, such as in racuo, or mosphere, (if desired atmospheric pressure) at a pressure less than in a space which can adjoin the place at which the seal, or closure, is to be made and then allowing the said molten metal, or alloy, to pass, or filter, preferably through a capillary tube, constriction, or the like, and run into the proper position to form the seal, or closure. lVe can thus produce, for example, a gas tight plug or stopper of lead, or like metal, or alloy, in a glass, or like tube. If desired the molten metal, or alloy, to be used as aforesaid, can be heated to a temperature considerably above its melting point to remove any occluded gas. A similar process may be applied to the production of a gas tight joint between vitreous material and metal wire by first introducing, or sealing, the wire into the vitreous material and then providing a portion of the vitreous material around the place where the metal wire projects with a gas-tight covering. or filling, of lead, or like metal, or alloy, which can, for

Specification or Letterl Pptent.

in an indifferent, or reducing, at-

Patented Nov. 24, 1914.

instance, when melted, as aforesaid, be run into a cup, or recess, in the vitreous material next 'to the place where the said wire passes through the vitreous material, the said lead, or like metal, or alloy, covering the projecting end of the wire so as to prevent air from passing between the wire and the lead, or like metal, or alloy.

If the gas-tight seal, or closure, is being made in a narrow tube, or if the surface of the vitreous material be not perfectly smooth, difficulties may arise on account of the high surface tension of the molten lead, or like metal, or alloy, but such difficulties can be conveniently overcome if, after melting the lead, or like metal, or alloy, in a vacuum, the lead, or like metal, or alloy, after it has reached its final position, and while in a molten state, has pressure applied, in any suitable way, to its free surface until the molten lead, or like metal, or alloy, solidifies. Such ressure may, for example, be applied by a mitting air, or other as, under suflicient pressure, to the free sur ace of the lead, or like metal, or alloy, while it is in a molten state and this may be done when there is a vacuum in the space into which the other end of the wire, enters, by allowing the air at atmospheric pressure to have access to the free surface of the molten lead, or like metal, or alloy.

The accompanying drawing represents, in longitudinal section, a tube of vitreous material and the following is a description, of an example of a way in which this invention may be performed.

metal wire 1, (say, for example, a molybdenum wire) is passed through the constriction at 2, the tube being constricted at 3 to a capillary form and a piece of lead, or the like, being placed in the tube, as at 4:, the said tube is closed in as at The tube is exhausted of air from the end 6. The tube may be softened at 2, so that, by atmospheric pressure, it will collapse upon the wire 1 and the vitreous material may be pressed in by a tool if desired. The metal at 4:, is then melted and passes through the capillary at 3, and into the space 7 below which has been highly heated, so that the metal covers the protruding end of the wire 1 as shown at 7. The end 5 of the tube is broken off while the metal at 7 is still hot so that atmospheric air enters and its pressure drives the said metal well home. lBe-' fore the metal at 7 has solidified the tube'can be cut at 8 and a wire (say a tinned wire) be introduced into the hot metal at 7 so as to constitute a leading-in wire if required.

What we claim is 1. A method of making gas-tight seals betweenmetal and vitreous material, which consists in melting metal which is of sufiicient plasticity to remain in contact with the vitreous material under varying temperature conditions and running it, under nonoxidizing conditions and. while molten, into position to form the required seal.

2. A method of making gas-tight seals be tween metal and vitreous material, which consists in melting, under non-oxidizing conditions, metal which is of suiiicient plasticity to remain in contact with the vitreous material and running it, under non-oxidizing conditions and while molten, into position to form the required seal. 1

3. A method of making gas-tight seals between metal and vitreous material, which consists in introducing a metallic wire into the vitreous material, melting metal which is of sufficient plasticity to remain in contact with the vitreous material under varying temperature conditions and running it, under non-oxidizing conditions and while molten, into position around the protruding end of the wire to form a seal around the said wire. r

4. A method of making gas-tight seals between metal and vitreous material, which consists in melting metal which is of sufiicient plasticity to remain in contact with the Vitreous material under varying temperature conditions and running it, under non-oxidizing conditions and while molten, into position to form the required seal and then applying pressure toperfect the seal.

5; A method of making gas-tight seals beder non-oxidizing conditions and while molten, into position around the protruding end of the wire to form a seal around the said wire and then applying pressure to perfect the seal.

In testimony whereof we have signed our names to this specification in the presence /of two subscribing witnesses.

HENRY JULIUS SALOMON SAND. FREDERICK REYNOLDS.

Witnesses to the signature of Henry Julius Salomon Sand:

R. M. CAVEN, H. LANBOURNEP Witnesses to the signature of Frederick Reynolds:

0. J. Wonrnr, L. lFnRNE.

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