Disposable Hermetically Sealed Container And Method

Abstract

A one-time use container for intermittently dispensing and storing chemicals out of contact with the air in which a container having a one way movable bottom or follower member is subjected to a suction for the eduction of stored fluid contents through a backflow check valve. The movable bottom slidably engages a cylindrical wall of a container under a sliding interface contact ranging from a close clearance frictional fit to an interference fit providing a radial displacement pressure strong enough to progressively expand the container wall as it moves. The interface contacting area is sealed against leakage of liquid and gases, and preferably lubricated, by a highly viscous fluid that is chemically inert to the liquid contents.

Parent Case Text

CROSS REFERENCES

The present application is a continuation-in-part of Ser. No. 545,007, filed Apr. 25, 1966, now Pat. No. 3,431,941, incorporated herein by reference.

Description

BACKGROUND OF THE INVENTION

Difficulty and danger has been experienced in safeguarding, storing and dispensing poisonous and highly reactive liquid and gaseous chemicals to avoid undesired oxidation, release of vapors and accidental contact with personnel, and particularly where there is intermittent dispensing of the hazardous fluid contents from a nonreusable storage container that is low enough in cost to be acceptable for assured one time use and then be thrown away. Either the opening of a conventional container exposes the contents to air and deterioration after partial dispensing, or the conventional containers are reusable and, in their reuse are dangerous because they might or might not be purged. This occurs particularly if the initial liquid was transparent or left a hazardous residue. Moreover, if removable caps are employed, there is the likelihood of continuing exposure of the stored liquid to the air, and to personnel. Also, the contents can be spilled and any threads or other securements can become contaminated or leak.

SUMMARY OF THE INVENTION

The inventive concept is to provide a variable capacity container which is of the exact effective size at any given time for any undispensed liquid remaining therein, and which prevents contact with air at all times, yet when emptied cannot be reused without critical destruction. An easily advanced movable follower bottom is provided which is inaccessible and unretractible as more particularly disclosed hereinafter. However, the container can be made as a reusable container with slight modification of tooling if packaged contents are harmless. Moreover, the container will not break, is rugged in handling and use and, short of crushing forces, will not leak under normal use and handling. Furthermore, the container can be made of any one of a number of plastics, including polyethylene, polypropylene, etc., for handling particular chemicals and, likewise, one of several highly viscous liquids can be used as a sealing means which will not be affected by, nor affect the chemical packaged.

One of the objects of the invention is to store and protect dangerous fluid chemicals around the home or garage from pets, children, and unknowing people who might try to use or play with them improperly or in a manner dangerous to them.

A further object of the invention is to provide a variable volume container which is a one time use container, yet with a slight production modification can be made to be a reusable container for mixing, storing and dispensing a wide range of chemicals.

The invention is characterized by a structural arrangement in which no mechanical device nor higher air pressure can be received inside the container without virtual destruction of the container for hermetic storage and dispensing operations.

The invention also contemplates a one time use fluid chemical storage and dispensing device from which no residual or vagrant liquid can be extracted after the supply has been exhausted and the device discarded.

Other objects of the invention is to provide a hermetically sealed container for storing and dispensing chemicals intermittently, which is inexpensive to manufacture, fill, and use, and is of great longevity and remains fully filled with any amount stored therein.

Another object of the invention is to provide a plurality of sizes of hermetically sealed containers which will receive and store any fractional quantity of their maximum capacity out of contact with air at environmental or atmospheric pressure at all times.

A further object resides in the ability of the container to dispense under suction a continuously hermetically sealed liquid from a substantially rigid container under negative gauge pressures whether induced by a pump or hydrostatic head.

The invention further provides a container whose storage space is liquid-solid at all times and under all conditions from the time it is charged until the time it is empty and is self-compensating under temperature variations.

A further object of the invention is to provide an improved sealing relationship between relative slidable elements at their interface area which includes a body of viscous fluid wetting, lubricating and sealing the surfaces of both elements in advance of a mechanically significant sliding engagement.

The invention is further characterized by a sealing element between two slidingly engaging surfaces which contacts every irregularity in the interface areas including the microgrooves and ribs left by surface finishing operations.

The invention further provides a viscous fluid containing long chain molecules between slidably engaging surfaces in a hermetically sealed variable capacity container to seal and resist displacement under pressure changes as high as 15 pounds per square inch across the interface area.

These being among the objects of the invention other and further objects will become apparent from the description and the drawings relating thereto in which:

Fig. 1 is a diagrammatic view of the device embodying the invention as used by way of example for horticultural purposes.

Fig. 2 is an enlarged side elevational view, partly in cross section, of a fluid container embodying the invention as formed of an extended cylindrical housing.

Fig. 3 is an enlarged section of portions of the upper two parts in preassembly form and position.

Fig. 4 is an enlarged section of the seal area of the container with the cooperating parts in their viscous seal receiving position.

Fig. 5 is an enlarged section of portions of the lower two parts in preassembly form and position.

Fig. 6 is an enlarged section through the upper nozzle after the valve is inserted and before it is heat sealed as shown in FIG. 2.

Fig. 7 is a section through another embodiment of the head construction shown in FIG. 2,

Fig. 8 is an enlarged section of the follower seal area of the container showing a modification of the structure shown in FIGS. 2 and 4, and

Figs. 9a and 9b are illustrative views of the container shown in FIG. 2 for purposes of explaining significant fluid dynamics of the invention.

Although this invention is described by way of example in connection with the horticultural aid for home owners who are unskilled in handling chemicals for application of solutions to plants for broad leaf herbicides and other benefits such as control of pests, it is not limited thereto and has many other uses in home, agriculture, parks, laboratories and industry where the container can be set on shelves or laid in racks as well as on the ground or a table.

The container of this invention can also be used where asceptic conditions are required and where it is desirable to withdraw liquid from the container by gravity, hydrostatic vacuum, or mechanically induced suction throughout the negative gauge pressure range evidenced by a pressure differential across the wall of the container. Any tendency to create an excessive negative gauge pressure therein is obviated by movement of the follower member within the container as the liquid is depleted. A feature of this invention is the provision of means to supply vapor-free liquids, mixtures and solutions at atmospheric pressure from vapor-free portable storage and dispensing containers which can be carried, set at any level with respect to a work area and disposed in any gravitational orientation or desired location.

Referring to FIG. 1 the container of this invention is illustrated at 10 as connected by means of a tube 11 to a mixing device 13 to supply under suction a chemical for mixture therein with water that is supplied thereto through a hose 17 from a spigot 19 of the water supply system of a house 21. The mixture passes from the device 13 under pressure through hose 23 to a nozzle 25 equipped with a spray control 27. The spray 29 thus provided is accurately proportioned, uniform in concentration and easily applied. The mixing device 13 and the container 10 are portable and can be located next to the nozzle 25 or at the spigot. Moreover, the container 10 can be secured directly to the mixing device to provide a unitary assembly if desired, or it can be carried on a person's shoulder by a sling involving two hook elements 15 at opposite ends as shown.

Referring now to FIG. 2 in further detail, the container 10 is made up of an extruded cylindrical housing element 12 preferably of a translucent material having a diameter approximately 25 percent to 33 percent of its height, and provided with at least one hole 14 located quite close to the bottom end 16. The element 12 comprises a section of a longer extruded tube which is drawn and vacuum formed in an external die or sizing sleeve and held to a predetermined internal diameter at the end of the extrusion process. The elements are cut from the longer extruded lengths and deburred at the inside edges by chamfering at 18 (FIGS. 3 and 4) either by reaming or by application of a heated cone if desirable. .Any tool marks that might be left upon the internal surface are minute and are disposed longitudinally. Typically, the size is held within .+-..005 inch in a 4 -inch diameter tube to receive therein two elements and a slidable bottom member between them in telescopic relationship.

The slidable bottom herein referred to as the follower 20 is preferably formed of a color coded material and has a head portion 22 that is slightly domed either conically, or spherically, as at 24 on one side with an annular axially extending flange 26 on the other side. The flange is provided with a shallow circumferential groove or recess 28 in the external face thereof bounded by upper and lower lands 30 and 32, respectively. Preferably the follower 20 is one of two identical members formed integrally and severed as the lands are lathe-trimmed to tolerance diameters in which the upper land, whether continuous or castellated, is within the range of slightly oversize to slightly undersize with respect to the housing diameter but not more than a few thousandths of an inch undersize, and the lower land is oversize with interference tolerances by as much as .020 inch on the radius and relieved on the inner edge as at 33 (FIGS. 2 and 3) to the inside diameter of the housing for an insertion starting clearance. If there are any machining marks remaining on the land surfaces after machining they are circumferential and disposed crosswise to the markings on the inner surface of the housing. Although acceptable, a high polish on these surfaces is not required but desirable.

The follower 20 is introduced through the mild chamfer 18 of the bottom edge of the housing and advanced until the lower flange 32 is just within the housing. In this preliminary position (FIG. 4) the hole 14 is in communication with the groove or channel 28 whereupon a gun (not shown) is applied to the hole 14 and the channel is filled under pressure with a viscous sealing liquid 31, later described, while the air displaced thereby in the channel escapes through the dry interfaces ahead of it. The pressure filling is stopped when the band of the sealing material 31 is complete as seen through the translucent material of the housing. Thereafter the follower is pushed upwardly beyond the holes 14 and the bottom closure element 34 is applied.

As viewed in FIG. 2 the bottom closure element 34 is vacuum formed from plastic sheet stock, is likewise domed as at 36, and below its apex 37 is exteriorly supplied with a frangible nipple 38 that is to be ruptured preliminary to dispensing to admit air to the space between it and the follower 20 when the container is unpacked and readied for dispensing operations.

As seen in FIG. 5 the annular downwardly extending flange 40 of the bottom closure is preferably flared radially outwardly slightly to provide a pressure fit when it is pushed into place in the bottom of the housing 12 to the point where the housing and flange edges 16 and 41 are substantially coextensive. The bottom closure in its insertion and location carries the follower member 20 upwardly leaving behind a very thin coating of viscous sealant below it over a portion of the interface between the closure flange 40 and the housing wall 12. Thereafter the flange and housing wall are either tacked together by heat fusion at points 39, or, continuously all the way around the circumference of the housing and flange. Any interface points not tacked, are sealed by the sealer coating mentioned left there as the follower was moved upwardly.

The closure of the upper end can be accomplished by a head member constructed in several ways, either as an integral part of an open bottom body that is blow or injection molded or a vacuum formed separate member inserted and fused in place. In any of these a valved conduit is provided which is fused shut at the tip after filling to provide a frangible nipple that can be cut away for dispensing operations.

Considering the head shown in FIG. 2 which is formed separately and applied, a vacuum formed closure member 42 that is applied comprises a like-domed portion 44 having a bordering flange 46 flared moderately upward and outwardly for a tight fit in the upper end 47 of the cylindrical housing 12 where it is marginally heat sealed permanently in place at the interface edge portions 49 of the flange 46 and the housing.

At the apex 45 of the dome a nipple is integrally formed with the outer end open or trimmed to leave a tubular element 55 (FIG. 2) having a passage of predetermined inside diameter to receive an injection molded nipple 48. The nipple has a tapered outer wall shaped to provide a dispensing tube 50 and an external flange 53. Internally thereof a cylindrical inner wall is provided defining a passage 51 to terminate upon the inner surface of the dome in a radial flange 52 defining a valve seat 54 and a reduced valve port 56.

A ball check member 58 is provided in the passage 51 and a coiled compression spring 57 is inserted having its upper turns enlarged slightly to frictionally engage the walls of the passage 51. The compression spring 57 is compressed a predetermined distance to establish a pressure that preferably requires approximately a 2 p.s.i. differential to open the valve in the embodiment being described.

With the head 42 in place and the tubular element 55 open the container is ready for filling and in this form can be sent along with the loose nipple to the packager. The container is then filled to a level a predetermined distance below the apex 45, the nipple is inserted and the flange 53 heat-fused to the end of the tube. Vacuum is then applied to the liquid level therein to advance it to the valve port 56. This step tests and indicates the operativeness of the follower 20 and places a slight packaging vacuum on the seal 31 and contents. Thereafter, a heated element engages the upper end of the tubular element 55 to reduce the diameter of the passage above the spring and seal it closed with a frangible tip 49 that can be cut away when liquid is to be dispensed from the container.

In FIG. 7 a modification is shown in which a wide mouth passage 51a is provided in the closure member 42a which provides sufficient access to move the follower 28a downwardly for repeated uses as where the packaged contents themselves might be viscous liquids.

A snap-on closure can be provided to close the opening 51a it being appreciated that its sealing relation is augmented by vacuum conditions induced inside the container, but preferably a cap 64 is threaded as at 66 onto a flange 48a defining the opening 51a, and the cap in turn carries the suction nipple or tubular element 48 for the purposes already described. Filling the container can be accomplished through the opening 51a by removing the cap 64 when the container is emptied and the follower returned to its lower limit either mechanically or by the pressure of the refilling liquid forcing the follower downwardly. In this particular embodiment the top of the follower 20a can either be modified as indicated at 66 (FIG. 7), or the lower contour of the closure cap 42a changed to be conical or domed to the contour shown in FIG. 2 so that complete nesting and emptying of the container can be accomplished in either case. It is to be observed that in either instance a catch area for any spillage of dangerous concentrates is provided around the education nozzle where it is safely held until harmlessly washed away or removed.

In operation, when a dispensing device such as shown in said patent application and FIG. 1 is attached to the nipple after the tip 49 is removed, suction can be applied to the nipple strong enough to open and withdraw liquid past the valve. The frangible portion 38 on the bottom closure 34 is perforated to admit air and the dispensing device is turned on. Liquid will be withdrawn and the follower 20 will move upwardly with the viscous sealing material 31 being applied to the inner wall of the container and wiped by the lower flange 32 as it expands the wall of the container outwardly as shown at 62. This enlarged portion travels upwardly with the follower 20, the wall yielding outwardly above the flange and recovering essentially its normal diameter after the flange has past.

Considering now the dynamic balance of the embodiment when disposed upright as shown in FIG. 9a and when inverted as shown in FIG. 9b, and assuming the velocity of the follower is low, the forces acting down equal the forces acting up.

For FIG. 9a:

1. (p.sub.i A + f + W) = p.sub.a A or,

2. (p.sub.eA + whA) = p.sub.i A or,

Similarly for FIG. 9b:

2.

or, in general for any case:

where, k = (+1) for FIG. 9a and (- 1) for FIG. 9b and (0) for instances where the container lies on its side.

From these equations it can be stated that the pressure (p.sub.i) on the inside surface of the follower is always less than atmospheric (p.sub.a) in FIG. 9 a or in the case where the container is on its side, and is less than atmospheric in FIG. 9b, providing the weight (W) of the follower is no greater than that required to overcome its frictional drag (f). It is this singular aspect of p.sub.i that is distinctive of embodiments of the invention.

It should be noted that even if the weight (W) of the follower be greater than the frictional drag, such as might be desired for a self-emptying container, i.e., no external suction (p.sub.e) applied, when set upright the pressure on the inside surface of the follower will be less than atmospheric provided backflow into the container is prevented, irrespective of the height (h) of the liquid above it, as by a valve (FIG. 9a without flow). In the absence of such restriction the follower would just fall downward under (W) and (h) factors.

In most applications the frictional drag exceeds the follower weight on account of the sealing process. Thus, in the static condition a restriction preventing backflow into the container is desirable only when the container is upright, FIG. 9a, and if the weight of the fluid (h) acting downward on the follower exceeds the frictional drag (f). However, such restriction may still be required to prevent unwanted movement of the follower under jarring or shaking forces. Under the action of such forces, the development of pressure less than atmospheric pressure acting on the inside surface of the follower prevents movement.

Significant considerations indicate that the follower:

l. Is moved in essence by atmospheric pressure with only its own weight possibly aiding such movement;

2. The pressure against which it moves is less than atmospheric pressure with the only exception being when the container is inverted and if then the weight of the follower exceeds its frictional drag;

3. No mechanical linkages or members extend to the outside to actuate, or are actuated by, the follower;

4. The energy it consumes in its movement is created by the suction force supplied to the liquid-- thus, the term "follower."

Assuming that only a part of the liquid is dispensed and the container is to be stored for a length of time, the hose 11 is dismantled and the container 20 is set upright on a shelf. Due to the closed valve and weight of the liquid therebelow, the pressure at the top of the liquid will be subatmospheric, if there is any differential at the valve, and the pressure at the seal 31 will be the weight of the liquid above it. Under this resting condition this pressure is applied against the viscous material and is effective between the follower 20 and container 12 above the lower land, urging the sealing material jointly against the lower land and the container wall, thereby inhibiting any downward leakage of liquid through the sealing material. Nor will the follower 20 retract since the hydrostatic weight to move it downwardly in the enlarged portion 62 is always less than the vacuum pressure that is required to draw it upwardly to shift the enlargement, which pressure differential reflects the pressure setting of the valve.

Setting the container down hard on the shelf only closes the valve more forcefully, while backflow under pressure is obstructed by the check action of the valve 58. Moreover, downward pressure on the dome 24 of the follower 20 urges an increase in diameter of the upper land 30 and thereby tends to tighten it against the sidewall of the container. On the other hand, in the event the follower 20 tends to stick on its upward movement, the dome 24 is arched more tending to reduce the effective diameter and the friction of the upper land on the sidewall. The dome, by flexing, enables continuous dispensing even though the follower 20 may move by small increments.

Once the movable bottom has reached the closure head, their nesting relation will empty the container and the follower will be located at the top where it is inaccessible to physical or hydraulic movement without destroying the container by cutting off the top head portion. However, once the head portion is removed, even though the follower can then be forced downwardly, the follower serves as nothing more than a permanent bottom thereafter and the container as a cup. Thus, a safe one-time-use sealed container is provided. Furthermore, even if badly mistreated, any residual liquid below the follower will be most difficult to drain and cause damage because the opening at 38 is at the apex of the dome 36.

Considering the dynamic fluid sealant, the practicableness of the follower concept rests upon the ability to obtain an air and fluid tight seal between the follower and the inside wall of the container-- a seal that will remain tight over a period of possibly years-- without developing frictional forces that prevent movement of the follower when desired.

Theoretically, an absolutely smooth and perfectly round peripheral surface on the follower will naturally form a perfect seal when mated with zero clearance at the interface area with a cylindrical wall having similar characteristics. However, in practice a certain amount of surface roughness and irregularity can be expected, and practical tolerances make zero clearance impossible of achievement. Consequently, there will always be interstices at the interface such as gaps, streaks, voids, scratches and other means permitting fluid passage between the two mating parts.

Materials having nearly perfect elastic properties, i.e., elastomers, could be used to fill in such voids under some conditions, but such materials and elements are expensive, costly to shape and constitute additional elements to assemble. Moreover, they are prone to chemical attack, and can provide excessive frictional contact. The sealant embodiment of the present invention fills and follows the contours of all interstices and can be infinitely controlled for optimum results by varying the viscosity of a liquid:

1. For a given leakage configuration between the follower and cylindrical wall, leakage will be reduced as the viscosity of the fluid is increased.

2. If the viscous fluid possesses an agent which forms a film upon drying, a surface film will form where the fluid comes in contact with air as it tends to leak out, thus preventing further leakage, providing the flow is reduced sufficiently through viscous action to allow sufficient time for the film formation.

As an example, consider the case of a cylindrical container having an inside diameter (D) of 4 inches with a mating cylindrical follower having a diameter .004 inches less and a length (L) of 1 inch. The radial clearance (C) is thus .002 inches. Assuming water is the fluid contained above the follower; that there is one foot of height (h) in the container; and, that there is no vacuum above it. Water has:

w, the spec. weight = 62.4 (lbs./ft..sup.3)

Thus, the leakage will be: ##SPC1##

The addition of a thickener to the water which will increase its viscosity 100,000 times as great is then made. With this viscosity the leakage will be greatly reduced:

Actually, on account of point (2), supra, this leakage would not exist because a surface film would have formed and dried shortly after leakage had been initiated, such as by having filled the container. On the other hand, maintaining a clearance of .002 inch over the length of follower travel would be practically impossible and utilizing a fluid of such viscosity would almost certainly be impractical. Thus, an even smaller clearance is required with the result that there preferably will be some mechanical interference, the degree depending on the manufacturing process and manufacturing tolerances. By eliminating the thickener from the contained fluid and instead placing it in an isolated ring around the periphery of the follower, the desirable properties of the dynamic fluid seal may be retained without contaminating the fluid contained.

The leakage paths present with an interference fit consist of a number of isolated and disconnected individual interstices, paths, such as scratches, and individually can be better represented by:

where d is the mean diameter of the path. This indicates that the leakage varies inversely with the first power of viscosity similar to the film leakage formula set forth above.

Such a viscous fluid may be of the viscosity of honey or grease and is made either of a material selected for its optimum inertness with respect to the liquid stored in one-time-use containers, or a solution of the liquid stored protected, of course, against oxidation and biodegradation, if necessary, in containers for repeated use. Silicone compounds may be used or a long-chain polymer additive such as, by way of example, the polyethylene oxide which is marketed as Polyox 301 by Union Carbide Chemical Co. and has a molecular weight of 5 .times. 10.sup.-6 . It is used in a finely divided powder mixed in aqueous solution and injected into the channel 31, it being noted that any cross-marking of the interface surfaces of the lands 32 and the housing assure the admission and retention of the sealant over the entire interface with the interface engagement constituting minute ribs sliding crosswise upon each other. When the polymer hydrates to form the viscous sealing material the viscolastic polymers establish themselves as having a long ropelike configuration. The long chain molecules then striate in the direction of follower movement and, as additive advantages are not only difficult to dislodge but wet and lubricate the interface area. Any stored liquid contacting the viscous mixture merely dilutes the upper edge of the seal 31 as it recedes slightly during dispensing operations with some remaining on the increasing expanse of wall of the container below the follower. In this connection it should be noted that the interfacial interference and friction between the land 32 and container wall can be varied for ease of movement of the follower if desired.

Other than a packaged viscous liquid being used as its own sealant along with an interrupted upper land 30, there can be used with an uninterrupted land 30 any stable liquid as a sealant having viscosity and lubricity properties sufficient to lubricate and seal the moving parts of the container of this invention. Liquids of natural or synthetic origin having viscosities in the range of about 100 to 1000 or more SUS at 100.degree. F. may be used. Examples of synthetic lubricants that are preferred because of their lubricity stabilities, oxidation resistance and related properties are silicones, C.sub.1-- C.sub.10 aliphatic esters and di-esters of C.sub.8 -- C.sub.12 organic acids (octyl sebacates), polyalkylene oxides, polyalkylene glycols, hydroxy ethyl cellulose, fluorohydrocarbons, organic phosphates, and organic silicates.

The axial width of the flange 26 may be varied but it is preferred that it be approximately one-fourth of the diameter of the movable bottom so that cocking in its movement may be prevented.

Although the two spaced lands 30 and 32 are shown which orient and delimit the expanse of the sealing material 31, as already described, it is to be noted that the land 30 is essentially a guide land and once a viscous sealant is in place, its main function is to guide the follower if the container is upright. The upper land 30 is shown interrupted in FIG. 4 for purposes of further explaining the availability of the container for repeated use in conjunction with the closure member 42a shown in FIG. 7 where the dispensing nozzle 50 of FIG. 2 is provided on the cap removably covering a large access opening 51a in the closure member where a viscous liquid is being dispensed. The containers with the head closure member 42a are sold separately with instructions or shipped empty to the packager and the viscous liquid can be filled through the opening 51a (FIG. 7) and the closure 42a applied.

It will be noted that with contrast of the coloring or opaqueness of the liquid contents, the amount of liquid remaining in the container can be read on the container scale 68 against the meniscus effect at 70 of the upper edge of the land 30 of the color coded follower which is accentuated by the solid width of the color coded sealing material 31 therebelow as seen through the wall of the container 12.

Furthermore, it is to be noted that with the viscous liquid sealant sealing the interface between the movable bottom and the wall of the container, the interference dimensions of the lands with the wall of the container can be relaxed to the point of clearance as already suggested and the closing pressure of the valve spring can also be relaxed or even eliminated, for dispensing at a less eduction vacuum pressure on the liquid contents. It is appreciated that the container can be laid on its side in a rack and also be inverted in which the tube 11 may be depending and its length extending below the bottom of the liquid contents will supply a hydrostatic vacuum to drain or siphon the contents from the container. The siphoning can be controlled with a pinch clamp or cock valve, or other manually controlled valve, applied to the depending eduction tube in a conventional way.

Thus, the container and dispensing conditions for dangerous liquids can be tailored to the experience or lack of experience of the expected user, for home, laboratory, or industry, either as a one-time-use "throw away" container, or for repeated use.

Although only one land can be used if the follower is otherwise held normal to the axis as it advances, the axial width of the land or lands 30 or 32 is essentially only of mechanical significance. Because of controlled viscosity their sealing effect is effective whether they were very narrow or quite wide. Any fluid getting past the upper guide or land is obstructed by sealant at the lower land, and the reverse would be true if the follower were to be used on a reusable basis with an upper land 30. In brief, any seepage into the sealant is trapped in the sealant before it reaches the other land.

The term suction action is intended to include any form of continuous or intermittent suction or withdrawal force such as a vacuum, gravity flow or a siphoning action exerted against the contents of the container. The suction preferably operates to assist in preserving sealant interface contact with the container when the container is made of mildly resilient nonbreakable material. This provides a pronounced resilient interface pressure effect resulting in either a bulge at the scaling land, if the wall of the container is thin enough to be resilient, or a depression of the land 30 if the wall is unyielding, or both.

Having thus set forth the objects and described a preferred embodiment of the invention and several modifications with their novel arrangement of parts and results attained, it will be seen how the stated objects are attained, particularly in the safe handling of chemicals by users of varying experience.

Claims

I claim:

1. A container for storing liquids out of contact with air between occasions of dispensing them under suction action comprising:

a tubular housing member;

an outlet head at one end of the housing having an eduction passage therethrough for suction action, said housing being open to atmosphere at the other end when dispensing liquid;

a follower member slidably closing said other end of the tubular housing to define a storage space and having an annular wall portion frictionally engaging the tubular housing in guided relationship and defining with the inner wall of the tubular housing an interstice between the follower and housing interface surfaces in communication with said storage space;

one of said members being made of a mildly resilient material; and

a liquid lubricant within said interstice to seal the wall portion against the passage of liquid contents therepast.

2. The container in accordance with claim 1 in which the lubricant is a member of the group consisting of silicones, C.sub.1-- C.sub.10 alkyl esters of C.sub.8-- C.sub.12 organic acids, polyalkylene oxides, polyalkylene glycols, fluorohydrocarbons, organic phosphates, organic silicates, hydroxy ethyl cellulose and mixtures thereof.

3. The container in accordance with claim 2 in which said lubricant is a polyalkylene oxide.

4. The container in accordance with claim 3 in which said lubricant is a viscous mixture of water and a polyalkylene oxide.

5. The container in accordance with claim 4 in which said polyalkylene oxide is polyethylene oxide.

6. The container defined in claim 1 in which said stored fluid is a liquid and said lubricant comprises a viscous mixture of said stored liquid and polyethylene oxide.

7. The combination called for in claim 1 in which said eduction passage includes a check valve closing against the flow of liquid from said container, and means urging said check valve under pressure to its closed position.

8. The combination called for in claim 1 in which said outlet head comprises an outwardly dished central portion surrounded by an outwardly extending flange supported in sealed relationship to the edge of said container wall.

9. A container for storing liquids out of contact with air between occasions of dispensing them under suction action comprising:

a tubular housing member;

an outlet head at one end of the housing having an eduction passage therethrough for suction action, said housing being open to atmosphere at the other end when dispensing liquid;

a follower member slidably closing said other end of the tubular housing to define a storage space and having an annular wall portion defining with the inner wall of the tubular housing an annular space between the follower and housing interface surfaces in communication with said storage space, one of said members being made of a mildly resilient material;

said annular wall including a flange internally exposed to atmosphere inwardly of said annular space in a radial direction and having axially spaced land elements delimiting said annular space; and

a liquid lubricant within said annular space to seal the wall portion against the passage of liquid contents therepast.

10. The container defined in claim 9 in which one of the land elements is circumferentially interrupted to engage the inner wall of said tubular housing in guided relation for receiving viscous liquid contents therepast.

11. A container for dispensing and storing chemicals at negative gauge pressures out of contact with air comprising:

a cylindrical extruded plastic housing member;

an outlet head at one end of the housing member having an outlet passage therethrough, with an integrally formed reduced size valve port at its inner end;

a check valve in said passage urged to restrict outflow through said port and permanently secured in said passage;

a slidable follower member closing the other end of the housing and having a flange internally exposed to atmosphere engaging the inner wall of the cylindrical housing; and

viscous liquid means interengaging said flange and housing member at their interface surfaces to seal them against the escape of liquid chemicals in said housing member, at least one of said members being made of mildly resilient nonbreakable material.

12. The container defined in claim 11 in which said flange includes two spaced lands defining an annular chamber between them holding said viscous liquid means.

13. The container defined in claim 11 in which said flange includes an annular land engaging the inner wall of the cylindrical housing member and defining an annular space between the follower and housing and between the land and the liquid storage space for receiving said viscous liquid means.

14. The combination called for in claim 9 in which said follower is inwardly dished towards said outlet head to provide a cavity on one side and a projection on the other to nest therein and displace substantially completely the contents of said container, said flange in part defining said cavity, and said follower yielding slightly radially inwardly as it moves towards said outlet head.

15. In a container for dispensing and hermetically storing liquid chemicals the combination of:

a cylindrical housing having two openings adjacent one end; and

a follower slidably received through one of the two openings to be disposed in said one end to define a storage space in said container and having an annular space axially bounded by two spaced lands defining with the wall of the container an annular chamber in communication with the other one of said openings and sealed from said one opening by the land remote from said storage space.

16. The combination defined in claim 15 in which the remote land trails in the slidable movement of the follower and is in frictional contact with the wall of the chamber under pressure, said remote land resiliently bulging the wall at the area of contact.

17. The combination defined in claim 16 including a viscous liquid in said chamber received through said one of said openings to seal said annular space against leakage from said storage space and lubricate the interface between the trailing land and the wall of the chamber. 18A variable volume container for dispensing and storing liquid chemicals out of contact with air comprising a cylindrical housing of mildly resilient nonbreakable plastic:

an outlet head closing one end of the housing and having an outlet passage therethrough;

a bottom member follower exposed to atmosphere closing the other end of the housing and having a flange marginally engaging and mildly bulging the inner wall of the cylindrical housing in frictionally sliding relation under radial contact differential pressure, the higher one of which is atmospheric pressure; and

means for sealing the interface area between said bottom member and the inner wall of the housing against the escape of chemical contents from the housing including a body of viscous liquid lubricant chemically unaffected by said chemical contents disposed between said interface area and said chemical contents of said housing to seal said interface area from

atmosphere as the follower advances towards said head. 19. The combination called for in claim 18 in which said follower is of mildly resilient plastic and the outlet head and follower are domed outwardly in the same direction and the head includes frangible outlet means for eduction of

liquid chemical stored in said housing. 20. The combination called for in claim 18 in which the outlet head has an axial flange secured in sealing relationship with said one end of the housing, and including a bottom closure having an axial flange secured in sealing relationship with the other end of the housing, and frangible means for venting to atmosphere

the space between said bottom closure and follower. 21. A container for storing liquids out of contact with air between occasions of dispensing them under suction action comprising:

a tubular housing;

an outlet head at one end of the housing having an eduction passage therethrough for suction action, said housing being open to atmosphere at the other end when dispensing liquids;

a follower member slidably closing said other end of the tubular housing to define a storage space and having an annular wall portion defining with the inner wall of the tubular housing an interstice between the follower and housing interface surfaces in communication with said storage space;

a liquid lubricant within said interstice to seal the wall portion against the passage of liquid contents therepast;

a closure for said eduction passage;

said tubular housing having a charging opening through the wall of the housing and communicating with said interstice when said follower is in a lowermost position; and

cover means closing said other end of said tubular housing and said

opening. 22. A seal comprising two closely fit surfaces of mildly flexible walls defining an area under pressure contact induced by atmospheric pressure on opposite sides of said walls to hold said surfaces frictionally against relative sliding movement, and a viscose liquid in said area to lubricate and seal said sides and exposed to atmosphere at

the edge of the pressure area. 23. The process of sealing a movable follower in a cylindrical wall comprising moving the follower in the cylindrical wall with frictional sliding engagement therewith under radially directed atmospheric pressure, and bathing the interface area between the cylindrical wall under atmospheric pressure with a viscous liquid inert to the contents disposed on one side of the follower and

drying where exposed to atmosphere. 24. The process of sealing a liquid in a variable volume container comprising subjecting the liquid to suction action slidably moving a movable container wall portion at an interface area of contact with a remaining wall portion to vary the volume of the container, and bathing the interface wall portions with a viscous material in contact with the liquid in the container upon one edge of the contact area to seal the liquid and drying the viscous material with atmosphere upon the other edge.