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US 4,171,757 AGranted
Pressurized barrier pack
OwnerGeorge B. Diamondinventor
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OwnerGeorge B. Diamondinventor
Estimating the term…
The invention provides a low pressure package or packaging system for dispensing a product of high viscosity, namely, 10,000 cps. or above at a pressure of only about 6-40 lbs. per sq. in. gauge (psig). The low pressure reduces the safety hazard to practically zero, reduces the cost of the container very substantially and minimizes the use of metals, plastics and other scarce materials. The container is preferably provided with a barrier in the form of a piston, bag, disc or the like, to separate the product from the propellant. By reason of the low pressure, the wall of the container can be relatively thin, of the order of 0.005 inch or less in the case of aluminum in 2-inch diameter containers. The necessary thickness of materials other than aluminum (such as steel, plastic, paper board or laminates of metal, plastic and paper) will depend on their relative strengths. The use of such thin-walled containers lowers the cost of the package and at the same time renders the wall so flexible and pliable that the wall conforms to the piston or disc barrier which helps to prevent by-pass or escape of propellant gas and also allows the pressure inside to smooth out any dents occurring during transportation. The conformation of the wall to the barrier also permits almost complete expulsion of the product. The valve is provided with a sealing disc or head secured to a tiltable stem. The sealing disc is of considerably larger diameter than those of prior valves, and maybe three or four or more times the internal diameter of the stem. The disc hinges on a small portion of its perimeter to provide a passageway for the product extending throughout 360.degree..
As an article of manufacture, a self contained, sealed pressurized barrier container formed of flexible material and sealed at one end and having a discharge valve at the other end, a piston in the container and serving as a gas tight sealing barrier therein for defining two chambers, one chamber communicating with the valve and containing a product for discharge at the pressure of a propellant within the other chamber of the container, the container being of such reduced thickness and strength that it could not withstand an internal pressure in the container greater than 120 psig, the wall of the container being thick and strong enough to contain the internal pressure to 120 psig and being thin enough so that even at low internal pressure, the piston may move through the container and during such movement may somewhat deform and restore the container wall if it had been deformed before the piston had moved therethrough, the piston having such strength as to be able to conform to the wall of the container and the container wall being sufficiently deformable that the piston maintains its seal with the container wall as the piston moves through the container, the valve being constructed, on opening, to afford an effective flow-through cross-sectional area allowing a useful rate of discharge of at least 0.8g per second at the said pressure and maintaining an effective flow rate at the reduced pressures following incremental discharges from the container.
As an article of manufacture, a container body suitable for use in the manufacture of a valved, self contained, sealed, pressurized container, the container being sealed at one end and open at the other end for receiving the product to be discharged and for receiving also a control valve for manually regulating the discharge of the product, the container having a bottom wall provided with a port for receiving a propellant under pressure, the container being of such reduced thickness and strength that it cannot withstand an internal pressure greater than 120 psig, the wall of the container being made of flexible material such that dents in the wall are capable of being straightened out by the internal pressure, the body having therein a slidable barrier piston to serve as a separator between a to-be-dispensed product introduced through the open end and a propellant introduced through the port in the bottom wall;
The method of filling self contained, sealed, pressurized containers which are to be charged with a quantity of a product to be dispensed therefrom, and with a propellant, comprising providing a container open at the top and having a bottom wall with a charging port therein, the container housing a movable container wall sealing barrier piston therein, the container being of such reduced thickness and strength that it could not withstand an internal pressure greater than 120 psig, the wall of the container being thick and strong enough to contain the internal pressure to 120 psig and being thin enough so that, evan at low internal pressure, the piston may move through the container and during such movement may somewhat deform and restore the container wall if it had been deformed before the piston and moved therethrough, charging the product through the open end into the space above the barrier piston, sealing a valve assembly to the upper edge of the container, and charging a gaseous propellant into the space below the barrier piston until a pressure of 6 to 40 psig at room temperature is reached, or a liquid propellant until a pressure of 6 to 24 psig at room temperature is reached, and then sealing the charging port.
Dependencies are inferred from the claim text.