US1995993A

US1995993A - Vacuum insulated container

Info

Publication number: US1995993A
Application number: US731205A
Authority: US
Inventors: Jesse T Littleton
Original assignee: Corning Glass Works
Current assignee: Corning Glass Works
Priority date: 1934-06-18
Filing date: 1934-06-18
Publication date: 1935-03-26
Anticipated expiration: 1952-03-26

Description

March 26, 1-935. T, LlTTLEToN 1,995,993 I VACUUM INSULATED CONTAINER Filed June 18, 1934 I NV EN TOR. JZISSL T l 771. a 7'0.

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Patented Mar. 25, 1935 UNITED STATES" PATENT opt cs (Jorning Glass Works, poration of New York Application June 18,1934, Serial No. 131,205 r Claims. (01. sis-1s) This invention relates to vacuum insulated containers and more particularly to such 'a container which is provided. with an opening at each end.

Vacuum insulated containers, commonly called vacuum bottles, are usually constructed of an inner blank commonly known as an inner piston and an outer blank commonly known as an outer piston, which blanks or pistons are formed, with 10- bulbous portions and neck portions, the latter.

being sealed together at their outer ends in such a manner that a space is formed between the inner and outer pistons which isvevacuated. This provides an eflfective insulation which prevents 15 the contents of the container from being aflected by external atmospheric conditions. Sometimes it is desirable to employ a vacuum insulated container having an opening at each end in which case neck portions are formed at opposite ends so of the bulbous portions of the pistons and these neck portions are then sealed, together in such a manner that access may be had to the interior of the inner piston from either end of the container.

Such containers are,'however, diiiicult to manuzs i'acture as it is well known that after glass has been sealed it must be subjected to an annealing operation in order to release'the strains introduced when the seal is made; The 'annealingof a glass article necessitates subjecting it to a temso perature at or above its strain point and subsequently cooling it to atmospheric or its service temperature at a predetermined rate which is cal-- culated in accordance with the physical characteristics of the glass composition from which the 35 article is made. With hollow Was'sels-it is diillcult to obtain proper balance between the cooling rates of the internal and external portions and this diinculty is greatly magnified when the internal and external walls are separated from each. other' as .they are in vacuum'insulated containers. As a a result, double ended vacuum containers of the 'type to which this invention relates are subject to breakage during annealing due to the diilerences in expansion between the inner and outer pistons. Moreover, such containers are apt to break in service owing to the fact that when a hot liquid, for instance, is introduced into the inner piston the latter will become heated and m expansion of the inner? piston will take place while the outer piston is yet in its normal state. Hence the seals between the inner and outer pistons are strained and frequently such strains exceed the tensile strength of the glass with the i6 result that a crack or actual breakage will occur differs from .that of the glass from which destroys the vacuum insulation and the entire container is then rendered useless. The object of my invention is to overcome the diiliculties heretofore experienced in the manufacture and use of vacuum insulated containers having openings at opposite ends.

The above and other objects be accomplished by employing my. invention which embodies among its features a vacuum insulated container in which'the inner piston is made from 10 a glass having a coefficient of expansion which which the. outerpistonismade. a I

Other features embody the use of graded seals between the inner and outer pistons when the diflerences of expansion between them is so great that diflicultyisexperienced in eflecting sealing the two diil'erent glasses together.

In the drawing: r

Fig.1isasidevi partlyinsecti'onofs nc-120v uum imuiated con er constructed in .accordance with my invention; and

Fig. 2 is a fragmentary sectional view of a modifled form of my invention.

Referring to the drawing in detail, a vacuum container designated generally 10 consists of an inner piston 11 and an outer piston 12 which are sealed together at

opposite ends

13 and 14. The inner piston 11 is preferably formed froma' glass having a coemcient of expansion which is slightly 3 below that of the outer piston 12 so that in cooling from the annealing temperature the outer piston will be thrownunder a slight tension the inner piston will be thrown under compression. This, then, produces a strained condition in the vessel until the space 15 between the inner and outerpL tons l1 and 12-has been exhausted when atmospheric pressure on the exterior of the outer piston 12 will tend' to collapse it, thus exerting a compressive stress on it and cbunteracting 40 the tensional stresses which it previously pos-i i sessed. Due to the tendency of theatmosphere to expand the inner piston 11 into the evacuated space, any compressional which it previously possessed will be counteracted, at least to some extent, and proper balance will be maintained with the result that breakage due to strain is less likely to occur.

In the modification shown in mg." 2. the inner 'j piston 16 of a vacuum insulated container'desisnated generallyl'l is formed of a glass havinga much lower coeflicient of expansion than that from which the outer piston'l8 is made, with the result that a direct and eil'ective seal between the two glasses could not be made. Hence, I employ a u graded seal 19 between the inner and outer pistons and by so doing I am enabled to produce double ended vacuum insulated containers which will meet a widevarietyof service conditions.

While in the foregoing thae has been shown and described the preferred embodiment of my invention, it is to be understood that minor changes in the details of construction, combination, and arrangement of parts may be resorted to without departing from the spirit and. scope of my invention as claimed. What I claim is:

l. A double walled container comprising an inner member and an outer member sealed together at the ends, the latter being formed of material having an expansion coeifiicient which differs from that of the inner member.

2. A doublewalled container comprising an inner member and an outer member sealed together at their ends, the latter being formed of a material having a higher expansion coeflicient than that of the inner member. I

v 3. A double walled container comprising an inner member and an outer member, the latter being formed of material having an expansion coeflicient which differs from that of the inner member and a graded seal between the inner and outer members.

4. A double. walled container comprising an inner memberand an outer member, the latter being formed of a material having, a higher ex-' pansion coeflicient than that of the inner member and a graded seal between the inner and'outer members.

5. A vacuum insulated container comprising an inner piston and an outer piston both the innet and outer pistons having neck portions at opposite ends, the inner and outer pistons being sealed together at the outer ends of the neck portion and being formed of glasses having dil- Ierent coeflicients of expansion.

6. A vacuum insulated container comprising a glass inner piston havingneck portions at opposite ends and an outer piston formed 0! a glass having a'higher coefllcient of expansion than that iromwhich the inner piston is made and having neck portions at opposite ends, the outer ends 01' the neck portions being sealed together.

7. A vacuumins ted container comprising an inner piston or glass, an outer. piston formed 0! a glass having a coeiiicient or expansion which differs from that from which the inner piston is made, both the inner and outer pistons neck portions and graded seals joining the re, spective outer ends of the neck portions 0! the outer and inner pistons.

8. A vacuum insulated container comprising glass inner piston-having neck portions at opposite ends and an outer piston formed or a glass having a higher coefllcient or expansion than that from which the inner pistonis made and having neck portions at opposite ends, graded seals icining the respective outer ends of the neck portions :of the outer and inner pistons.

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