US 3282306 A
Description (OCR text may contain errors)
Nov. 1, 1966 M. s. GREENHUT PROCESS AND APPARATUS FOR THE CHARGING 0F CONTAINERS Filed April 2, 1964 United States Patent 3,282,306 PROCESS AND APPARATUS FOR THE CHARGING OF CONTAINERS Marvin S. Greenhut, Massapequa, N.Y., assignor to Pastemaster, Inc., Seaford, N.Y., a corporation of New York Filed Apr. 2, 1964, Ser. No. 356,721 8 Claims. (Cl. 1417) This invention relates to the liquid filling of containers and, in particular, to their filling through a small peripherally located opening.
In many applications the filling of containers is carried out by the simple expedient of pouring the liquid into the container. Where controlled flow utilization is desired, a cover may then be aflixed to the container; the cover containing a small outlet which is provided with either a valve, cap, or replaceable insert for re-sealing the container. Where, however, for functional or economic reasons, the container must be made in a single integral piece, but with a small opening for controlled flow, the filling is obviously not so simple, since relief must be afforded for the air which the liquid will displace during the charging process.
A partial solution to the problem is to inject the liquid into the opening with suflicient needle play to allow the air to escape. The container may, on the other hand, be directly charged without a needle if an air escape is provided elsewhere in the container. Neither solution is completely satisfactory. In the former, the needle must be fairly fine; its dimensions, of course, being dictated by the diameter of the container opening. With fine bore needles, this leads to an excessively slow liquid flow rate, particularly when high viscosity liquids are involved. Further, with this arrangement, one must be prepared to meet the high cost inherent in precise positioning jigs and adjunct equipment, and the needles must be periodically flushed and carefully maintained.
The latter or direct charging method is also unsatisfactory because the air escape hole must be subsequently plugged or sealed, thus adding to the cost of charging. Again, the precise positioning of the container opening with respect to the charging apparatus raises the cost of the equipment and its maintenance.
It is therefore an object of this invention to provide a process and apparatus for the cheap and expeditious charging of containers through a small peripheral opening.
It is a further object of this invention to provide a process and apparatus which satisfies the foregoing obiect and which can be employed with high viscosity liquids, such as paste.
It is a still further object of this invention to satisfy the foregoing objects without submerging the container or otherwise getting the liquid on the containers exrcrior.
Briefly, the invention is predicated upon the concept 'of exhausting the air contained within the container and that immediately surrounding it, while the containers aperture is coupled to the liquid to be charged, and then returning the surroundings to ambient or atmospheric pressure, so that the pressure diflerential between that on the liquid and that inside the container forces the liquid up, through the opening and into the container.
The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will best be understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings wherein:
FIG. 1 illustrates the inventive arrangement for carrying out the liquid charging;
FIG. 2 shows the container to be charged; and
FIG. 3 is a detail cross section of a portion of the container and its relationship to the float plate and liquid.
Turning now to FIG. 1, there is shown a vessel composed of a drum-shaped bottom portion 10 and a fitted hemispheric top 12 adapted by the gasket 14 to provide a hermetic seal against the pressure differential to be im posed. Since the vessel will be evacuated, this pressure differential results in a compressive force on the gasket obviating the necessity of bolting the top to the bottom (although such an arrangement may prove helpful in some circumstances). The top is provided with an annular flange portion 12' to aid in its initial placement and maintain its position relative the bottom. Both the drum and top are of suflicient thickness to withstand vacuum pressures (negative pressure relative the atmosphere) anticipated in the process. The level of the liquid 16 is maintained within predetermined limits by the storage vat 18 coupled to the drum 10 via the valve 20.
At this juncture, it bears mentioning that, although the vessel may take any form, for example square, a round shape more easily withstands the pressure differential which tends to buckle vessels of a similar thickness, but non-round shape. Further, so that this specification will not be unduly burdened by its repetition, it will be assumed that any portion of the described apparatus having contact with the liquid or its vapor is preferably composed of an inert material.
Atop the liquid is a circular float comprising an annular member 24 and plate 22; the latter of which contains a plurality of apertures 22' therethrough, each for accepting a predetermined portion of the associated cigar-shaped container 30, shown more clearly in FIG. 2. (For purposes of clarity and to avoid cluttering FIG. 1, only the front rank of containers is depicted.) The annular member and plate may be either integrally formed of the same material or the annular member itself may provide the floatation force. In either case, the specific gravity of the combination must be sufliciently low with respect to the liquid to permit floatation Without overflow on the plate top, notwithstanding the final filled nature of the containers.
As shown in the FIG. 3 detail, the container bottom 32 adjacent the opening as well as the plate apertures 22' are in the form of cone frustums, thereby restricting the containers downward movement and at the same time preventing its skewing. A suflicient portion of the container protrudes below the plates under-surface to allow the opening 31 thereof to remain in constant liquid contact between the two load extremes (i.e. containers empty and full). Where the containers are cheaply manufactured, without close tolerance restrictions, a flange 33 may be added to more surely limit the container travel into the plate aperture; further, the flange and container frustum may act jointly without the shown clearance. Needless to say, the particular form of the container, its shape where it contacts the float, and the float itself may take any form so long as the above described function is preserved. Inthe embodiment of FIG. 2, it may also prove helpful to provide small relief holes (not shown) in the plate to permit the trapped air to escape.
Coupled to the vessels top 12 is :a vacuum source 26 which may, for example, comprise a high vacuum motor adapted to reduce the pressure inside the vessel to that necessary for a predetermined filling of the containers (as will be described). Because such sources are generally provided with one-way valving arrangements, no valve is shown between the source and vessel. Should, however, an extremely quick reduction in pressure be desired, a vacuum sink may be inserted between the source and vessel; the source thereby acting continuously and direct- 1y upon the sink, rather than intermittently upon the vessel.
Mounted upon the vessel top 12 are a vacuum gage 27, the scale of which is graduated in inches of mercury vacuum (in. of Hg Vac.) from to 30, and an air relief valve 28 for returning the vessel to atmospheric pressure.
The process for filling the containers with the apparatus shown in FIG. 2 will now be described. Before doing so however, the containers themselves, as well as their purpose and function, will be briefly outlined in order to lay a foundation for an understanding of that which follows. The containers are of blow-molded polyethylene and are of sufficient thickness to maintain their shape during the charging process, as well as the ultimate use; the latter being the application of paste to any surface, the paste being squeezed out through the small opening and the container being resealed by a pin insert.
The containers are loaded in an opening-down attitude in their respective float-plate apertures, so that, as previously discussed, their lowermost portions contact the liquid. The top is now placed on the vessel and the air exhausted. The rate of air exhaustion depends upon the material used for the containers, its thickness, and of course, the capacity of the vacuum source. Thus, for example, if the air were evacuated too quickly, the pressure differential between that inside and that outside the containers could result in their bursting. 011 the other hand, too slow an evacuation of the vessel delays the charging process. For a polyethylene container of approximately .04 inch in thickness, 30 cc. in volume, an opening of .05 inch and a vessel of several cubic ft. in volume, three seconds from atmospheric to final vacuum pressure has proven satisfactory.
During the time that the air is evacuated from the vessel, air bubbles out of the container and through the high viscosity liquid paste, exhausting more slowly from the containers interior than that surrounding it. This differential tends to maintain the shape of the container and prevents its collapse. It might also cause its bursting unless, as previously mentioned, the rate of evacuation and the thickness of the container is suflicient. The final pressure depends upon the degree to which it is desired that the container be filled. Thus, for example, where it is desired that the container be 85% filled, the vessel pressure should be dropped to approximately 25 in. Hg Vac. A greater drop in pressure will afford a greater degree of filling, and so on. When the final pressure has been reached, the vacuum sources operation is discontinued.
The air is now allowed to reenter the vessel through the relief valve, and the containers slowly suck in the paste. More technically, the pressure differential between that on the liquid surface and that inside the container forces the liquid up through the opening and into the container. The rate at which the air is allowed to reenter the vessel depends upon the viscosity of the liquid, the container material and its thickness, and the diameter of the opening. Too fast a return to atmospheric pressure will deform the container, collapsing it inwardly, since the pressure outside the container returns to normal quicker than the liquid can fill it. Thus, the cartridge must have sufficient resiliency to withstand this new pressure differential. Approximately 25 seconds has been found satisfactory for the liquid and container described. During the return to atmospheric pressure, the liquid level in the vessel naturally decreases, since a portion of it enters the containers. Because, however, of the flotation arrangement, the disposition of the containers with respect to the liquid remains unchanged.
After the vessel has regained atmospheric pressure, the containers are removed. Although the opening is at the bottom, the liquid remains inside due to the conjunctive action of the liquid meniscus in the opening and the air pressure within the container above the liquid.
The process may now be repeated with new containers being inserted in place of those filled. The fluid level is maintained within predetermined limits by the manual opening of the storage vat valve when necessary. Care must be exercised to ensure the valve is closed during the air exhaustion process to preclude the possibility of the liquid being unknowingly sucked into the vessel.
While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims.
1. The process for charging with liquids a plurality of containers each having a single opening therein comprising the steps of:
maintaining said containers inside a vessel, containing said liquid, with their respective openings in continuous communication with said liquid regardless of its level;
evacuating said vessel and the air in said containers through said liquid; and
allowing said vessel to reachieve ambient pressure whereby the liquid is sucked up into said containers.
2. The process for charging with liquids a plurality of containers each having a single opening therein comprising the steps of:
floating said containers opening submerged in a vessel containing said liquid and maintained at atmospheric pressure;
evacuating said vessel and thus the air in said containers; and
allowing said vessel to reachieve ambient pressure whereby the liquid is sucked up into said floating containers.
3. The process claimed in claim 2, in which said vessel is evacuated to a pressure of at least 25 in. of Hg Vac. and in which said vessel reachieves ambient pressure slowly.
4. An apparatus for charging with liquid a plurality of containers each having a single opening therein comprising:
a vessel for receiving therein the liquid to be charged in said containers;
a vacuum source coupled to said vessel for reducing the pressure therein;
means for allowing air to reenter said vessel in a controlled flow; and
a float for receiving a plurality of said containers and maintaining their respective openings in continuous contact with said liquid regardless of its level in said vessel.
5. The apparatus claimed in claim 4, in which said float comprises a planar plate having a plurality of apertures therethrough for receiving the containers to be charged.
6. The apparatus claimed in claim 5, in which the plate apertures and container ends adjacent the opening are in the form of reciprocal cone frustums.
7. The apparatus claimed in claim 5, in which said vessel is cylindrical and said float is circular.
8. The apparatus claimed in claim 4 further comprising:
means for refilling said vessel with liquid to be charged in said containers.
References Cited by the Examiner UNITED STATES PATENTS 1,259,879 3/1918 Lascoff 1417 X 2,544,416 3/1951 Emery et al. 14139 2,877,611 3/1959 Anrep l4131 X FOREIGN PATENTS 999,411 10/1951 France.
LAVERNE D. GEIGER, Primary Examiner. E. EARLS, Assistdnt Examiner.