US3476277A

US3476277A - Vacuum bottles having improved bottom closures

Info

Publication number: US3476277A
Application number: US693558A
Authority: US
Inventors: Robert M Rownd
Original assignee: ROBERT M ROWND
Current assignee: ROBERT M ROWND
Priority date: 1967-12-26
Filing date: 1967-12-26
Publication date: 1969-11-04
Anticipated expiration: 1986-11-04
Also published as: GB1204820A; FR1599420A; DE1816448A1

Description

R. M. RowND 3,476,277

VACUUM BOTTLES HAVING IMPROVED BOTTOM CLOSURESv Nov. 4, 1969 2 Sheets-Sheet N VEN TOR Per ogzzll mjy 2 Sheets-Sheet 2 R. M. ROWND VACUUM BOTTLES HAVING IMPROVED BOTTOM CLOSURES lll/'11111111 a 1. 1, I. l. A'. l.

Nov. 4, 1969 v Filed Dec. 26, 1967 l/ Il f y "o7 United States PatentO Int. Cl. A47j 41 /02 U.S. Cl. 215-13 19 Claims ABSTRACT oF THE DISCLOSURE A vacuum bottle having a vacuum insulated receptacle, a generally cylindrical protective jacket preferably made of resinous plastic material and received around said receptacle, and a bottom closure having a disen-gageable screw connection with the lower end` of said jacket, said bottom closure having an annular sidewall portion with an outwardly facing frusto-conical end surface, said jacket having an inwardly facing frusto-conical surface engaging said frusto-conical end surface on said bottom closure for holding said annular side wall of said bottom closure inwardly against outward expansion, said frusto-conical annular surfaces being in sealing engagement. The frustoconical annular surface on said bottom closure is preferably at a smaller angle to the axis of the vacuum bottle than the frusto-conical annular surface on said jacket. In one embodiment, the upper end of the bottom closure is formed with a V-shaped annular point while said jacket is formed with a downwardly facing V-shaped annular groove, mating with said point. The fruSto-conical annular surfaces are formed on said point and groove. Preferably, the included angle of said V-shaped annular point is smaller than the included angle of said V-shaped annular groove.

This invention relates to vacuum bottles or thermos bottles of the well known type having a vacuum insulated double walled receptacle, received within a protective jacket. The invention is particularly applicable to vacuum bottles in which the protective jacket is made of a resinous plastic material.

In most cases, the protective jacketA is provided with a removable closure so that the vacuum insulated receptacle can be removed and replaced. In this way a new vacuum insulated receptacle can be installed if the original receptacle is broken due to some accident.

The present invention relates particularly to vacuum bottles in which the protective jacket is provided with a removable bottom closure. In certain prior constructions, a screw threaded connection was provided between the bottom closure and the lower end of the jacket. External threads were provided on the lower end of the jacket. The bottom closure had an annular side wall, formed with internal threads. In some cases a sealing ring was provided between the jacket and the annular side wall of thebottom closure. The purpose of the sealing ring was to make the vacuum bottle submersible, so that it could be immersed in wash water, while preventing any of the water from leaking into the space between the .vacuum insulated receptacle and the jacket.

"truded outwardly beyond the jacket, which was unsightly.

3,476,277 Patented Nov. 4, 1969 Moreover, the outwardly protruding wall of the bottom closure tended to snag on clothing and the like.

The present invention provides a vacuum bottle having a jacket with an improved bottom closure which screws onto or is otherwise removably secured to the jacket. Outward expansion of the side wall of the bottom closure is prevented. Moreover, the joint between the bottom closure and the jacket is sealed against the entry of water. To accomplish these new results, the adjacent side wall portions of the jacket and the bottom closure are formed with mating frusto-conical surfaces which prevent outward expansion of the bottom closure. Preferably, the frusto-conical surface on the bottom closure faces outwardly, while the mating frusto-conical surface on the jacket faces inwardly. The angle between one frustoconical surface and the axis of the vacuum bottle is preferably smaller than the angle between the other frustoconical surface and the axis, so that the engagement between the frusto-conical surfaces is localized. In this way, the sealing pressure between the frusto-conical surfaces is increased so that a leakproof seal is produced. To provide extra assurance that the joint will be leakproof, a small amount of a sealing composition may be employed between the frusto-conical surfaces. Such sealing composition may comprise ordinary petroleum jelly, or a more sophisticated sealant, such as a silicone liquid or silicone grease.

In one embodiment, the adjacent side wall portions of the jacket and the bottom closure are formed with a V-shaped annular point and a V-shaped annular groove, mating with the point. The frusto-conical annular surfaces are formed on the point and the groove. Preferably, the point is formed on the bottom closure, while the groove is formed on the jacket. However, this situation may be reversed. It is preferred to form the point with a smaller included angle than the included angle of the groove. This results in localized sealing engagement between the point and the groove, so as to insure a tight seal therebetween.

Various other objects, advantages and features of the present invention will appear from the following description, together with the accompanying drawings, in which:

FIG. 1 is an elevational view, partly in longitudinal section, of a vacuum bottle to be described as an illustrative embodiment of the present invention.

FIG. 2 is an enlarged fragmentary section, corresponding to the lower left-hand portion of FIG. 1, and showing the joint between the jacket and the bottom closure.

FIG. 3 is an elevational view of a modied vacuum bottle, to be described as another embodiment of the invention.

FIG. 4 is a fragmentary longitudinal section of the vacuum bottle of FIG. 3.

FIG. 5 is a fragmentary enlarged longitudinal section, showing a portion of the joint between the jacket and the bottom closure, with the components partially disengaged.

FIG. 6 is a fragmentary section corresponding to a portion of FIG. 5, but with the jacket and the bottom closure fully engaged.

FIG. 7 is a fragmentary longitudinal section showing details of the jo-int between the jacket and the liner for the vacuum bottle, with the components partially disengaged.

FIG. 8 is a section similar to FIG. 7, but with the components fully engaged.

As previously indicated, FIGS. 1 and 2 illustrate a vacuum bottle 1, which comprises the usual double walled vacuum insulated receptacle or filler 2. Normally, the liller 2 is made of glass, and thus is quite fragile. The illustrated filler 2 comprises inner and outer walls 3 and 4, with an evacuated space 5 therebetween. The upper ends of the inner and outer walls 3 and 4 are connected together by a curving rim portion 6. The ller 2 has a mouth 7, through which liquids are poured into and out of the ller.

As illustrated, the lower end of the outer wall 4 is formed with a tubulation 8, constituting the sealed off remnant of the tube through which the space 5 was evacuated. A cup-shaped tip protector 9 is mounted on the filler 2 around the tubulation 8. The tip protector 9 may be cemented or otherwise secured to the filler 2. It will be understood that the tip protector 9 may be made of a resinous plastic material, metal, or any other suitable material.

The vacuum bottle 1 is provided with a protective jacket 10 which surrounds and protects the fragile filler 2. The illustrated jacket 10 is made of a resinous plastic material, but other suitable materials may be employed.

As shown, the jacket 10 is generally cylindrical in shape. It has a slight upward taper, which facilitates the molding of the jacket from a resinous plastic material.

Near its upper end, the jacket 10 has a slightly reduced portion 11 adapted to receive a drinking cup 12 in an inverted position. The cup 12 is preferably made of a resinous plastic material, but may be made of other suitable materials. When not in use, the cup 12 may be mounted on the upper end of the jacket 10. Mating screw threads 13 and 14 are preferably formed on the jacket 10 and the cup 12, for disengageably securing the cup to the jacket. The screw threads 13 are formed on the reduced portion 11 of the jacket 10.

Above the reduced portion 11, the jacket 10 is still further reduced to form a neck portion 15. Means are provided on the neck portion 15 to retain the filler 2 in the jacket. Thus, the illustrated neck portion 15 is formed with an inwardly projecting annular flange 16 which overhangs the curved upper end portion 6 of the filler 2. A soft resilient sealing ring or gasket 17 is illustrated as being interposed between the flange 16 and the filler 2. The sealing ring 17 prevents any leakage of liquids between the upper ends of the filler 2 and the jacket 10.

A stopper 18 is illustrated as being mounted in the mouth 7 of the filler 2, to retain liquids therein. The illustrated stopper 18 is adapted to be removably secured to the neck portion 15 of the jacket 10. Thus, the stopper 18 is formed with a mounting ring 19 which has an outwardly projecting flange 20 and a downwardly projecting iiange 21. In the illustrated construction, mating screw threads 22 and 23 are formed on the neck portion 15 and the flange 21, for disengageably securing the stopper 18 to the jacket 10.

The illustrated stopper 18 is hollow and thus is formed with a cavity 24. The upper end of the cavity 24 is closed by a disc 25. The cavity 24 may be lled with an insulating material, such as ground cork, if desired.

A pouring lip 26 projects upwardly and flares outwardly from the ange 16 on the jacket 10. The pouring lip 26 makes it easy to pour liquids from the vacuum bottle, without causing the liquids to run down the side of the jacket 10.

To enclose and retain the filler 2, the lower end of the jacket 10 is closed by a bottom closure 27, which is removably mounted on the jacket. The illustrated closure 27 is generally cup-shaped, and thus comprises a bottom wall 28 and an annular side wall 29. Means are provided on the bottom wall 28 to support and retain the filler 2. As shown, a soft resilient sleeve 30 is introduced between the bottom wall 28 and the filler 2. The sleeve 30 is snugly received around the tip protector 9. The upper end of the sleeve engages a shoulder 31 on the tip protector 9. It will be seen that the sleeve 30 is received within and located by a generally cylindrical socket member 32 which projects upwardly from the bottom wall 28. Longitudinal ribs 33 are formed within the sleeve 32, to engage and support the sleeve 30. Preferably, the sleeve 30 is made of natural or synthetic rubber. The sleeve provides a firm yet resilient support for the fragile filler 2.

The jacket 10 and the bottom closure 27 are formed with adjacent annular

side Wallv portions

34 and 35 which are disengageably joined. As shown to best advantage in FIG. 2, the upper side wall portion 35 on the bottom closure 27 is received around the outside of the lower side wall portion 34 on the jacket 10. Means are provided for dsengageably securing the bottom closure 27 to the jacket 10. In the illustrated construction, such means comprise

mating screw threads

36 and 37 on the

side wall portions

34 and 35. The illustrated screw threads 36 on the jacket 10 are external, while the screw threads 37 on the bottom closure 27 are internal. The screw threads may be replaced with equivalent elements, such as bayonet lugs, for example.

In accordance with the present invention, means are provided to prevent the expansion or flaring of the side wall portion 35 on the bottom closure 27, due to tightening of the

threads

36 and 37. For this purpose, the illustrated vacuum bottle 1 is formed with an annular frustoconical surface 38 on the upper end of the side wall portion 35 of the bottom closure 27. A mating frusto-conical annular surface 39 is formed on the side wall portion 34 of the jacket 1t). The frusto-conical surface 38 on the bottom closure 27 faces upwardly and outwardly, while the frusto-conical surfaces 39 on the jacket 10 faces downwardly and inwardly. It will be seen that the frustoconical surface 39 is formed on the lower side of a ange 40, projecting outwardly from the side wall portion 34. The illustrated flange 40 is substantially flush with the outside of the side wall portion 35 on the bottom closure 27.

When the bottom closure 27 is screwed onto the jacket, the truste-conical surface 38 is pressed firmly against the frusto-conical surface 39. The inclination of the

surfaces

38 and 39 produces a camming action which obviates any possibility of outward expansion of the side wall portion 35.

The engagement of the frusto-

conical surfaces

38 and 39 produces a seal which prevents the passage of water through the joint between the jacket 10 and the Ibottom closure 27. To increase the efiiciency of the seal, the frusto-

conical surfaces

38 and 39 are preferably inclined at slightly different angles. Preferably, the angle between the frusto-conical surface 38 on the bottom closure 27 and the axis of lthe vacuum bottle is slightly smaller than the angle between the surface 39 and the axis. For example, in one construction, the angle between the frustoconical surface 38 and the axis was 60 degrees while the angle between the surface 39 and the axis was 68 degrees. Thus, the truste-conical surface 38 on the bottom closure 27 is preferably more sharply pointed or an-gled than the frusto-conical surface 39 on the jacket 10. With this construction, the engagement between the frusto-

conical surfaces

38 and 39 is localized toward the inside of the side wall portion 35. Due to the localized engagement, greater sealing pressure is developed between the

surfaces

38 and 39 when the

threads

36 and 37 are tightened. Accordingly, a tight seal is more easily developed between the

surfaces

38 and 39.

It will be seen that the side wall portion 35 of the bottom closure 27 comes to a V-shaped annular point 41 at its upper end. The point 41 is formed at the intersection of frusto-conical surface 38 and the inner surface 42 of the side wall portion 35. The inner surface 42 is generally cylindrical, but with a slight taper to facltate the molding of the bottom closure 27 from resinous plastic materials.

The V-shaped point 41 is adapted to mate with a V- shaped annular groove 43 on the jacket 10. The V-shaped groove 43 is defined by the intersection of the frustoconical surface 39 and the outer surface 44 of the side wall portion 34. The sealing engagement between the bottom closure 27 and the jacket 10 is localized by the V-shaped point 41.

To provide a greater assurance that a perfect seal will be formed between the bottom closure 27 and the jacket 10, a small amount of a sealing composition may be employed between the point 41 and the groove 43. For example, a thin layer of petroleum jelly may be applied to the point 41. Instead of the petroleum jelly, more sophisticated sealants may be employed, such as a silicone liquid or a silicone grease. Only a very small amount of sealant s required, so that the presence of the sealant Will not normally be apparent to the user of the vacuum bottle.

Due to the sealing engagement between the

frustoconical surfaces

38 and 39, the vacuum bottle 1 may be cleaned by immersing it in wash water, without any substantial hazard that water will leak into the space between the filler 2 and the jacket 10. The submersibility of the vacuum bottle makes it easy to clean.

The bottom closure 27 does not have to be removed unless the -iller 2 is broken, due to some accident. The bottom closure 27 is then unscrewed from the jacket 16, so that a new ller 2 may be inserted into the jacket. The bottom closure 27 is then screwed onto the jacket 16 until the frusto-conical surface 38 comes into sealing engagement with the frusto-conical surface 39. The sealing engagement is localized near the V-shaped point 41, so that is is easy to form a tight seal. The interlocking engagement between the point 41 and the groove 43 prevents any outward expansion of the upper side Wall portion 35 on the bottom closure 27. Thus, the side wall portion 35 remains ilush with the llange 40. There is no unsightly protrusion or flaring of the side wall portion 35 on the bottom closure 27.

FIGS. 3-8 illustrate another embodiment of the invention in the form of a modied vacuum bottle 45. It will be seen that the vacuum |bottle 45 is of the wide mouth type. Thus the vacuum bottle `45 comprises a vacuum insulated filler 46 having a wide mouth 47. The iiller 46 is like a jar, in that the mouth 47 is not necked down, but is as large as the body of the filler 46. In other respects, the ller 46 is similar to the filler 2. Thus, the iller 46 has inner and

outer walls

48 and 49, a rounded top edge 50, a tubulation 51, and a tip protector 52, which are similar to the corresponding elements of the iller 2.

The fragile ller 46 is enclosed within a protective jacket 53, preferably made of a suitable resinous plastic material. Examples of suitable materials are polyethylene, polypropylene and polystyrene. It will be understood that other materials may be employed.

As before, the jacket 53 is generally cylindrical, with a slight taper to facilitate the molding of the jacket. Near its upper end, the jacket 53 has a reduced portion 54 adapted to receive a drinking cup 55, which is similar to the cup 12.

Mating screw threads

56 and 57 are preferably provided on the reduced portion 54 and the cup 55, for disengageably securing the cup to the jacket.

The vacuum bottle 45 differs from the vacuum bottle 1 in that the vacuum bottle 45 has a protective liner 58 which is received within the inner wall 4S of the ller 46. The liner 58 prevents 'breakage of or damage to the filler 46. Wide mouth fillers are particularly susceptible to breakage, due to the insertion of spoons and other hard objects into the filler. Such vacuum bottles are very useful for holding hot and cold foods which are eaten directly out of the vacuum bottle. The liner 58 provides for the insertion of spoons or other implements, without any danger that the ller 46 will be broken or even scratched. Any small scratch generally results ultimately in the breakage of the filler. The liner 58 also makes it possible to use ice cubes in the ller, which would usually cause breakage of the filler in the absence of the liner.

The liner '58 is preferably made of a resinous plastic material, but may be made of other durable materials. Suitable plastic materials include polyethylene, polypropylene and polystyrene, for example.

Near its upper end, the illustrated liner 58 has a downwardly facing shoulder 59 which engages the curved upper edge 50 of the ller 46. The liner 58 has an enlarged mounting portion 60 which projects upwardly above the iller 46. The mounting portion 60 is adapted to receive a stopper 61. Means are preferably provided for disengageably securing the stopper 61 to the mounting portion 60. As shown, mating screw threads 62 and 63 are formed on the mounting portion 60 and the stopper 61.

At its upper end, the mounting portion 60 flares upwardly and outwardly to a pouring lip 64, which is formed at the upper extremity of an outwardly projecting annular llange 65.

A sealed joint is provided between the upper ends of the jacket 53 and the [liner 58, to exclude liquids from the space between the jacket and the iller 46. The formation of a joint at this point makes it possible to produce the jacket 53 and the liner 58 from two different plastic materials. Normally, the liner 58 is made of a plastic material which is light colored or transparent. However, it is generally preferable to use a darker colored plastic material for the jacket 53.

In the illustrated construction, the upper mounting portion 66 of the liner 58 is formed with a cylindrical outer surface 66 which is received within a reduced upper end portion 67 on the jacket 53. The outwardly projecting flange 65 overhangs the upper end of the reduced portion 67. It is preferred to provide a downwardly projecting annular tongue or flange 68 on the outwardly projecting llange 65. The illustrated flange 68 tapers downwardly and is adapted to be received in an annular groove 69, formed on the upper end of the jacket 53. The groove 69 has a taper which corresponds generally to the taper of the flange l68. The formation of the annular groove 69 on the upper end of the reduced portion 67 produces inner and outer upwardly projecting llanges 70 and 71 on the opposite sides of the groove. The inner flange 70 is adapted to be received in an annular groove 72, formed on the liner 58 between the flange 68 and the cylindrical outer surface 66.

It is preferred to spin-weld the joint between the jacket 53 and the liner 58 so that the joint will be mechanically secure and leakproof. Spin-welding is a Variety of heat welding, in which the heat between the plastic parts is developed by friction. One of the parts is spun relative t0 the other, as the parts are pressed into engagement. Of course, both parts may be spun in opposite directions, if desired. The spinning movement between the parts develops sufficient heat, due to friction, to soften the parts to a welding temperature. The spinning movement is then stopped so that the weld between the parts will be completed as the joint cools. In the illustrated vacuum bottle 45, the spin-weld is produced between the flanges 68, 70 and '71. To complete the weld, relative spinning movement is produced between the jacket 53 and the liner 58. In the illustrated construction, the inner llange 70 on the jacket 53 is higher than the outer flange 71, and also higher than the llange 68 on the liner 58. Thus, the greatest friction is developed between the upper end of the flange 70 and the groove 72 on the liner. The resulting frictional heat softens the lange 70, so that plastic material from the flange '70 llows into the groove 72, and also into the groove 69, to insure that a secure weld will be formed. After sullicient spinning movement to develop the required heat, the spinning movement is stopped so that the joint will cool, to complete the weld. The completed joint is shown to best advantage in FIG. 8. It will be seen that material from flange '70 has filled the upper extremity of the groove 72, and that the height of the flange 70 has been reduced, by displacement of the softened plastic material, so that all of the

flanges

68, 70 and 71 are the same height. Moreover, the flange 68 is securely seated and welded into the groove 69.

While a spin-welded joint is highly advantageous, it will be understood that the joint between the jacket 53 and the liner 58 may be completed in some other manner,

7 as by solvent welding, or the use of an adhesive material.

The vacuum bottle 4S of FIGS. 4-8 has a bottom closure 73 which is similar to the closure 27 of FIG. 1. Thus, the closure 73 is preferably made of a resinous plastic material, and is formed with a bottom wall 74 and an annular side wall 75. Supporting means are introduced between the bottom wall 74 and the tip protector 52 on the filler 46. As before, a soft resilient sleeve 75 is mounted around the tip protector 52. The upper end of the sleeve engages a shoulder 76 on the tip protector. A socket member 77 is provided on the bottom wall 74 to receive and support the lower end of the resilient sleeve 75.

The bottom closure 73 has an upper annular wall portion 78 which is received around a lower annular wall portion 79 on the jacket 53. Means are provided for disengageably securing the bottom closure 73 to the jacket 53. Such means preferably comprise

mating screw threads

80 and 81 on the adjacent wall portions '78 and`79.

Means are provided on the jacket 53 and the bottom closure 73 to prevent outward expansion of the upper side wall portion 78 of the bottom closure 73, when the

screw threads

80 and 81 are tightened. In this case, such means preferably take the form of a V-shaped annular point or tongue 82 and a V-shaped annular groove 83. The

elements

82 and 83 are adapted to interlock, so as to prevent outward expansion or flaring of the bottom closure 73, when it is screwed tightly onto the jacket 53. The

elements

82 and 83 may be interchanged between the

side wall portions

78 and 79 on the bottom closure 73 and the jacket 53. However, it is preferred to form the V-shaped point or key 82 on the upper end of the side wall portion 78 on the bottom closure 73, while the V- shaped groove 83 is preferably formed on the jacket 53.

As illustrated, the V-shaped groove 83 is formed on a downwardly facing shoulder 84, formed on side Wall portion 79 of the jacket, above the threads 81.

The V-shaped point 82 and the V-shaped groove 83 provide frusto-conical surfaces which act in a manner similar to the frusto-

conical surfaces

38 and 39 of the vacuum bottle 1. Thus, the V-shaped point 82 has an outwardly facing frusto-conical surface 85 which is engageable with an inwardly facing frusto-conical surface 86 of the V-shaped groove 83. The

surfaces

85 and 86 have a camming action which prevents any'outward flaring of the side wall portion 78 on the bottom closure 73.

In addition to preventing expansion of the side wall portion 78, the V-shaped point 82 and the V-shaped groove 83 form a seal, so as to prevent the leakage of water therebetween, into the space within the jacket 53. To provide for an easy and more effective seal, the included angle of the V-shaped point 82 is preferably less than the included angle of the V-shaped groove 83, so that the area of engagement between the point and the groove will be localized at the upper extremity of the point. The localized engagement increases the sealing pressure between the point and the groove, when the bottom closure 73 is screwed tightly onto the jacket 53. To cite an example, the included angle of the point 82 was 8O degrees, while the included angle of the groove 93 was 90 degrees. in one construction. These dimensions are indicated in FIG. 5. It will be understood, however, that these angles are subjected to wide variation.

The height of the V-shaped point or tongue 82 is preferably greater than the depth of the V-shaped groove 83 so that the point will penetrate into engagement with the upper extremity of the groove when the bottom closure 73 is screwed onto the jacket 53. -In one construction, the height of the V-shaped point 82 was 0.025 inch while the depth of the groove 83 was 0.020 inch. These dimensions are indicated on FIG. 5, but it will be understood that they are subject to Wide variation. When the point 82 is pressed into the groove 83, there is a small clearance between the shoulder 84 on the jacket 53 and the upper end surface 87 on the bottom closure 73. This clearance is indicated as 0.005 inch in FIG. 6, but, of course, this 8 dimension issubject ,towide variation. The clearance allows for compression of the point 82 to insure a good seal when the

screw threads

86 and 81 are tightened.

Here again, a small amount of a sealing composition may be employed between the point 82 and the groove 83 to make it easy to obtain a perfect seal. Any suitable sealant may be employed, such asa small amount of petroleum jelly, or a silicone liquide-or grease, for example.

Various other modifications, alternative constructions and equivalents may be employed without departing from the true spirit and scope of the invention,as exemplified in the foregoing vdescriptionjanddefined in the following claims.

I claim: 1. A vacuum bottle, comprising:

a vacuum insulated filler,

a protective jacket mounted around said filler,

means on saidjacket for engaging and 'retaining the l upper endpf said filler, l l

a bottom closure removably mounted on the, lower end of said jacket, A

and means on said bottom closure for engaging and retaining the lower end ofsaid filler, Y

said jacket and said bottom closure having adjacent annular wall portions with mating frusto-conical surfaces inclined at slightly different angles for holding said annular wall portion of4 said bottom closure against outward expanding movement. j

2. A vacuum bottle according to claim 1 in which said frusto-conical surfaces are in sealing engagement to form a seal between said jacket and said bottom closure.

3. A vacuum bottle according to claim l:

in which said frusto-conical surface on said bottom closure faces outwardly,

while said'frusto-conical surface on said jacket faces inwardly.

LA vacuum bottle according to claim 1:

in which said frusto-conical surface on said bottom closure faces outwardly,

while said frusto-conical surface on said jacket faces inwardly,

said frusto-conicalsurface on said bottom closure extending at a smaller angle to the axis of the vacuum bottle than -in the case of the frusto-conical surface on said jacket,

whereby the effectiveness of the sealing contact between said frusto-conical surfaces is increased.

5. A vacuum bottle according to claim 1:

in which said adjacent annular wall portions include a V-shaped annular point on one of said wall portions and a V-shaped annular groove on the other wall portion,-

said frusto-conical surfaces being formed on said V- shaped `annular point and said V-shaped annular groove. Y Y,

6. A vacuum bottle according to claim 5:

in which the included angle of said V-shaped annular point is smaller than the included angle of said V- shaped annular groove, Y

whereby said V-shaped annular point engages said V- ,shaped annular groove with localized line contact.

7. A vacuum bottle according to claim 6:

in which said V-shaped annular point is on said bottom closure,

while said V-shaped annular groove is on said jacket.

S. A vacuum bottle, comprising:

a vacuum insulated receptacle,

a generally j cylindrical protective jacket made of resinous plastic material and received around said vacuum insulated receptacle, j

,means on rthe upper end of saidjacket for engaging and retaining the upper end of'said receptacle,

a. generally cup-shaped bottom closure made of resinous plastic material for closingktheV lower end of said jacket,

said bottom closure having a bottom wall and an annular side wall portion projecting upwardly therefrom, means on said bottom wall for engaging and retaining said vacuum insulated receptacle,

said jacket having an annular side wall portion adjacent said annular side wall portion on said bottom closure,

said annular side wall portion of said jacket having a reduced annular portion received Within said annular side wall portion on said bottom closure,

mating screw thread means on said reduced annular portion and said annular side wall portion of said bottom closure for disengageably securing said bottom closure to said jacket,

a first frusto-conical annular surface inclined at one angle on the upper end of said annular wall portion of said bottom closure,

and a second frusto-conical annular surface inclined at another angle on said annular wall portion of said jacket mating with said first frusto-conical annular surface for holding the upper end of said annular side wall portion of said bottom closure inwardly against outward expanding movement.

9. A vacuum bottle according to claim 8:

in which said rst frusto-conical annular surface faces outwardly,

while said second frusto-conical annular surface faces inwardly.

10. A vacuum bottle according to claim 8 in which said rst and second frusto-conical annular surfaces are in sealing engagement.

11. A vacuum bottle according to claim 8:

in which one of said frusto-conical annular surfaces is at a smaller angle to the axis of the vacuum bottle than the other frusto-conical annular surface,

whereby the contact between said frusto-conical annular surfaces is localized to promote a tight seal therebetween.

12. A vacuum bottle according to claim 8:

in which one of said annular side wall portions is formed with a V-shaped annular groove,

While the other annular side wall portion is formed with a V-shaped annular point mating with said groove,

said frusto-conical annular surfaces being formed on said V-shaped annular point and said V-shaped annular groove.

13. A vacuum bottle according to claim 12:

in which the included angle of said V-shaped annular point is smaller than the included angle of said V-shaped annular groove,

whereby the engagement therebetween is localized to promote a tight seal therebetween.

14. A vacuum bottle according to claim 12 in which the height of said V-shaped annular point is greater than ythe depth of said V-shaped annular groove.

15. A vacuum bottle, comprising:

a vacuum insulated receptacle,

a generally cylindrical protective jacket made of resinous plastic material and received around said vacuum insulated receptacle,

means on the upper end of said jacket for engaging and retaining the upper end of said receptacle,

a generally cup-shaped bottom closure member of resinous plastic material for closing the lower end of said jacket,

said bottom closure having a bottom wall and an annular side wall portion projecting upwardly therefrom,

means on said bottom wall for engaging and retaining said vacuum insulated receptacle,

said jacket having an annular side wall portion adjacent said annular side wall portion of said bottom closure,

said annular side wall portion of said bottom closure being received around said annular side wall portion of said jacket,

mating screw threads on said annular side wall portions of said jacket and said bottom closure for disengageably securing said bottom closure to said jacket,

and interlocking tongue and groove elements inclined at different angles on said annular side wall portions for preventing outward expansion of said annular side wall portion of said bottom closure,

one of said tongue and groove elements facing upwardly while the other element faces downwardly.

16. A vacuum bottle according to claim 15:

in which said tongue element projects upwardly on said bottom closure,

while said groove element faces downwardly on said jacket.

17. A vacuum bottle according to claim 15 in which said tongue and groove elements are generally V-shaped.

18. A vacuum bottle, comprising:

a vacuum insulated receptacle,

a protective jacket made 'of resinous plastic material and received around said vacuum insulated receptacle,

and a liner made of resinous plastic material and received within said vacuum insulated receptacle,

said liner having an upper end portion with an outwardly projecting annular flange,

said ange being formed with a downwardly projecting annular ange which tapers downwardly,

said jacket having an upper end portion with an upwardly facing annular groove therein for receiving said downwardly projecting ange on said liner,

said groove having a taper corresponding to the taper of said downwardly projecting flange,

said downwardly projecting flange being securely bonded t-o said upper end portion of said jacket.

19. A vacuum bottle according to claim 18 in which Said downwardly projecting flange is frictionally welded to said upper end portion of said jacket.

References Cited UNITED STATES PATENTS 2,818,204 12/ 1957 Henchert et al. 220-39 XR 3,120,570 2/1964 Kennedy et al. 215-13 XR 3,144,167 8/ 1964 Schultz 220-63 3,258,147 6/1966 Round 21S-13 3,311,249 3/1967 Bell 215-13 3,331,522 7/1967 Bridges 215-13 GEORGE T. HALL, Primary Examiner