Valve and bag assembly for pressure dispensing

[57] ABSTRACT

For dispensing from a pressurized container without aeration, a bag for containing a pasty product is suspended beneath a container top by a ring member having a tapered, inward extending rim. The ring member is supported by the flexible outer part of the flange of a conventional elastic seal at whose center is located a conventional valve stem. The tapered rim fits the configuration of the downward deflected outer part of the seal flange, while the radially inner part of the seal flange seals against the undersurface of the container top.

Claims, 3 Drawing Figures

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Patented May 16, 1972

3,662,926

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3,662,926

VALVE AND BAG ASSEMBLY FOR PRESSURE DISPENSING

FIG. 2 is a sectional view showing the parts of FIG. 1 subsequently assembled with a container mounting cup and valve member. A tubular bag member is also shown, prior to sealing it to the ring member.

FIG. 3 is a view principally in section showing the parts of FIG. 2 finally assembled, filled, and mounted in a pressure dispenser, illustrated inverted and with the valve open for dispensing.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The conventional valve seal generally designated 10 is shown in FIG. 1 in its relaxed configuration as molded. Formed of natural or artificial rubber, it includes a tubular sleeve portion 11 presented vertically when the dispensing container is upright and having a downwardly presented outer retaining collar portion 12. At the base of the sleeve 11 is a grommet-like seal body portion 13 having a downwardly presented sealing seat surface 14. Extending outward from the base of the sleeve portion 11, the body portion has a radially enlarged flexible flange, whose upper surface 15 is molded in a plane, as shown in FIG. 1, and whose lower surface 16 tapers upwardly and outwardly to a thinned edge 17 at which it meets the upper surface 15.

Other conventional parts utilized in the present invention are shown in the other figures of the drawing. FIG. 2 shows a conventional container top mounting cup generally designated 20 having an annular planar top wall 21, a central flanged pierce 22 and an upturned outer wall 23 terminating in a rounded rim 24. The container mounting cup 20 is sized to fit into the mouth b of a dispensing container generally designated d with its wall 23 sealed within the mouth b by crimping. In an aperture in the bottom wall/of the container d is a conventional rubber pressurizing grommet g through which a gassing needle may be inserted.

A conventional valving member 30 is employed. In the embodiment shown it includes a rigid tubular spout 31 having a downwardly presented shoulder 32 which fits atop the outer end of the sleeve 11 of the seal 10. At the bottom end of the stem 31 is a valve head 33 whose upper surface 34 seats against the sealing seat 14 of the seal 10. Dispensing ports 35 through the wall of the steam 31 are provided immediately above the head surface 34. The outer diameter of the tubular spout 31 below its shoulder 32, in the region which passes through the seal sleeve 11, is of such diameter as to be tightly grasped and sealed therein.

Novel parts used in the present invention will now be described. Referring to FIG. 1, the seal 10 is shown pre-assembled with a bag mounting ring generally designated 40 which embodies the present invention. The ring 40 is formed of a plastic material, such as polyethylene, onto which a tubular bag member, to be described, may be mounted and sealed, as by heat sealing or supersonic sealing. It includes an annular upper surface 41, formed in a plane, whose outer diameter is slightly less than the mounting cup top wall 21. Extending downwardly from the outer edge of the annular surface 41 is a circumferential bag seating ridge 42; below it extends a tubu ^laf cuff portion 43, having an outer bag receiving surface 44 which tapers slightly inward as it extends downward, terminating in a diagonal taper 45 which merges into its lower edge 46.

The inner surface 47 of the cuff portion 43 is tubular. It extends upward to meet a radial inward extending suspension rim portion 50 whose undersurface 51 has a juncture 52 with the inner cuff surface 47 at a radius substantially equal to that of the outer edge 17 of the seal 10. From the juncture 52, the undersurface 51 slants upwardly as it extends inwardly, to terminate in a thinned inner edge 53.

The radial extent from the juncture 52 to the thinned inner edge 53 may be fairly small; at a minimum it must be large enough to avoid the possibility that the edge 17 may deflect so severely, under the weight of the bag, as to permit the bag to drop; and at maximum it should not be so large as to prevent sealing of the seal flange surface 15 against the undersurface

BACKGROUND OF THE INVENTION

Certain products, to be dispensed by squeezing rather than foaming, spraying or other types of aeration, have heretofore been packed in collapsible bags suspended within metal pressure dispensers. When a dispensing valve is opened, the pressure of gas surrounding the bag within the dispenser squeezes the bag to expel the product.

The problem how to suspend such a collapsible bag within a gas-pressurized metal dispenser has led to a variety of proposed constructions, usually either difficult to assemble or relatively expensive. As an alternative, products to be dispensed have in some cases been packed in a cylindrical container above a piston which is pressed upward by gas pressure beneath. This construction presents the possibility of leakage of gas pressure upwardly, especially where the product to be dispensed is not of a highly viscous consistency.

The principal purpose of the present invention is to provide an inexpensive valve and bag assembly which is especially suited for assembly and filling. Another purpose is to provide a construction whereby a part of the bag may be pre-assembled with conventional dispensing valve parts. Other objects will be apparent from the specification which follows.

SUMMARY OF THE INVENTION

In the present invention, that familiar type of pressure dispenser is used whose valve assembly includes a top member having a flat undersurface and with a central pierce, into which is fitted an elastic seal having a tubular portion extending through the pierce, a retaining collar portion extending thereabove, and a seal body portion therebeneath. The seal body portion has a radially enlarged flexible flange presented against the undersurface of the container top member. A relatively rigid valving member is normally seated against the seal body portion and is displaceable therefrom for dispensing.

I provide as part of such valve assembly a bag mounting ring 49 member molded of plastic preferably of a type which is sealable, by heat or supersonic sealing, to the top margin of a bag member, preferably a piece of thin, flexible-walled plastic tube whose upper and lower ends are open. Such sealing is accomplished after the preliminary assembly of the ring member with and as part of the valve assembly.

The ring member includes two integrally molded portions: a downwardly presented cuff portion, to which the top margin of the bag member is subsequently sealed, and an upper radially inward extending suspension rim portion. Their juncture 50 has an inner radius into which the flexible flange of the seal will elastically interfit. The inward extending suspension rim portion is tapered from the juncture to a thinned inner edge.

The seal member and ring member are pre-assembled; for this purpose a seal-retention inner projection may be provided 55 within the tubular inner surface of the cuff portion. This preassembly is then assembled with the container top and valve member, drawing the radially inner part of the seal flange against the top member undersurface and deflecting the radially outer seal flange part elastically downward, to press sealedly upward against the tapered rim portion of the ring. The upper margin of the bag is then sealed to the cuff portion of the ring member.

For filling, the assembly is inverted so the bag may be filled through its open, lower end, and the product sealed therein. The container top member, with the filled bag hanging by the ring member from the outer edge of the seal flange, is then crimped in place within the mouth of a dispensing container, and the container space surrounding the bag filled with a pres- γθ surizing gas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing the pre-assembly of a bagmounting ring member with a conventional elastic valve seal. 75

3,662,926 of the mounting cup top wall 21.1 have found it best to leave at least half of the radial extent of the seal flange surface IS, outwardly of the sleeve 11, in contact with the mounting cup surface 21. This requires that the radial inward extent of the flange-like suspension rim 50, from the juncture 52 to the inner edge 53, shall not exceed the radial extent of that part of the seal flange upper surface 15 remaining presented against the annular surface 21 of the mounting cup 20. With the taperingly thinned suspension rim 50 interposed under the mounting cup top wall 21, the outer portion of the seal flange surface 17 may be safely deflected elastically downward. It will tend to deflect in any event under the weight of contents of the bag to be described; and the thinned suspension rim 50 takes up the space which might be opened by suspending the weight of the bag and its contents on the edge 17 of the seal flange 15. In the present construction the weight is borne ultimately by the bearing of the seal collar 12 downwardly against the mounting cup 20.

While the radius of the juncture 52 is sized so that the elasticity of the edge 17 will hold the seal 10 and ring 40 preassembled to each other, as shown in FIG. 1, even more secure pre-assembly is achieved by providing, in the upper part of the cuff inner surface 47 just below the juncture 52, a radially inward seal retention projection 55. This term includes either an ₂5 inward ridge or an undercut, which may extend either around the entire tubular inner surface 47 or have two or more portions spaced from each other around the perimeter of surface 47. In any case its radial spacing from center is slightly less than the radius of the outer edge 17 of the seal flange 15. Al- 30 ternately, the radius at the juncture 52 may be slightly less than that of the seal outer edge 17, so that the elasticity of the edge 17 will hold the seal 10 fitted pre-assembled within the ring 40 as shown in FIG. 1.

Following such pre-assembly, these parts are finally assem- 35 bled with the mounting cup 20 and valving member 30, into the positions shown in FIG. 2, locked in place by the seal collar portion 12. A flexible plastic tube member 60, open at its top margin 61 and its bottom margin 62, is then mounted with its top margin 21 fitted over the bag receiving surface 44 of 40 the cuff portion 43 and seated against the ridge 42. It is there sealed, as by heat sealing if, for example, both the ring member 40 and the bag member 60 are formed of polyethylene. Alternately other sealing means, such as supersonic sealing or adhesive sealing, may be employed, using materials suited for that purpose.

In use, the parts assembled as shown in FIG. 2 are inverted, and a pasty substance to be disposed is filled into the bag 60 through its open lower margin 62. That margin is then similarly sealed. The assembly is then inserted into the mouth h of a disposing container d, and sealed by crimping the mounting cup wall 23 outwardly, in the conventional manner. Pressurizing gas is then inserted into the dispensing container d outwardly of the bag 60, by inserting a pressurizing needle through the sealing grommet g in the bottom of the container d in the conventional manner.

Alternately the sealing grommet g may be dispensed with; and a quantity of liquefied gas may be inserted under the mounting cup 20 before it is sealed within the container mouth b.

Due to the elasticity of the seal 10, sealing is preserved even when the dispensing container d is inverted for dispensing and the valving member 30 is opened as shown in FIG. 3. With the , · · - · -downward at the edge 17 of the seal 10, gravity imposes no force to offset the elastic resilience of the seal 10; this causes the upper flange surface 15 to press itself tightly against both the mounting cup surface 21 and the undersurface 51 of the suspension rim 50 of the ring member 40, pressing a gas-tight 70 seal.

The present invention is designed especially for quantity production. Since the bag member 60 is not included in the pre-assembly of the valve seal 10 and ring member 40, the assembly shown in FIG. 2 may be made on conventional valve 75 assembly machinery. Also, after the bag 60 is assembled to the rmg member 40, filled through its bottom margin 62, and heat sealed, the crimping of the valve, with filled bag, into the mouth b of the dispensing container d may also be accomplished on conventional assembly equipment.