Dispensing Package

Abstract

In a dispensing container for use in dispensing packaged articles wherein a biasing means is used to push the packaged articles towards an outlet therefrom, the particular improvement whereby a compressed polymeric foam is used as a biasing means, thereby providing a biasing force that remains more uniform with time as the package is emptied of articles and also avoids locally high pressures bearing on the packaged articles.

Parent Case Text

RELATED APPLICATIONS

This application is a continuation-in-part of copending and commonly owned U.S. Ser. No. 767,211, now abandoned filed Oct. 14, 1968 by Herbert H. Loeffler.

Description

BACKGROUND OF THE INVENTION

It has long been known to package articles in boxes in such a way that they are forced towards an exit port of the box by a biasing means placed on the opposite side of the articles from the exit port. Thus, for example, U.S. Pat. No. 977,305 to Heppe discloses such a packaging means. Because of the convenience of such automatic advancement of articles to be dispensed, other such devices have been developed over the years as witnessed by U.S. Pat. No. 2,592,138 to Gwoosh et al. wherein a stack of razor blades is urged towards an opening by a spring as the blades are removed one-by-one from the top of the dispensing case.

Such prior art devices, however, have a number of drawbacks which limit their utility in some applications. For example, there is a very nearly linear decay in force exerted by springs on the packaged articles as the spring expands. Therefore, the biasing force must be relatively high when the package is filled and relatively low as it nears being empty. While this factor is unimportant when metallic items like razor blades are being packaged, it can be a serious problem when more delicate articles (for example, membranes or like porous articles which can be reduced in porosity by extended storage at high pressures) are to be packaged.

Moreover, springs and like biasing devices require piston members to distribute their force over the entire lower surface of a stack of packaged articles. This additional piston member adds to the cost of the packaged item and can never be dispensed with unless the lowest of the packaged articles, e.g. a razor blade, can itself act as a piston. Moreover, the bottom of the package which supports the spring action must also be relatively heavy (or comprise a reinforcing insert) to accommodate maximum force exerted by a spring in the package.

SUMMARY OF THE INVENTION

Therefore, it is an object of the present invention to provide an improved positive-action dispensing package. It is a particular object of the invention to provide such a dispensing package that need not be compressed excessively on filling and that is adequate for the packaging of many relatively pressure-sensitive and/or abrasion-sensitive items.

Another object of the invention is to provide a dispensing package that can be readily and safely assembled either by machine or by hand.

Still another object of the invention is to provide an economical positive-action dispensing package that does not depend primarily on use of mass-production techniques for its economy and convenience.

Another object of the invention is to provide a simplified, positive-action, dispensing package whereby the pressure is exerted over such a large area of the packaged items being dispensed that an intervening piston board may, in a proper case, be dispensed with.

Other objects of the invention will be obvious to those skilled in the art on reading the instant specification.

These objects have been substantially achieved by using a compressible cellular, polymeric foam as a biasing means interposed between the bottom of a dispensing container and a stack of packaged items to be dispensed. The use of this foam enables a number of advantages to be achieved at once:

1. The foam may bear, with about equal pressure, over nearly the entire lower surface of the packaged articles. This advantage often obviates the necessity of a piston board and very nearly always allows the use of (1) a lighter weight container and/or (2) a lighter weight piston board.

2. The foam will not lose its pressuring capabilities at a linear rate as it expands. The force exerted by a spring in expanding to four times its compressed rate will drop to one-fourth of its original force. A foam, however, may be selected that will drop to only one-half or even only three-quarters of its force during a like expansion. Conversely, pressure required for a reasonably efficient filling of a "foam-pressured package is reduced." This is particularly helpful in hand-fill packaging operations.

3. The foam provides a good protective reinforcement of the box as it expands. Whereas a spring, as it expands, allows a hollow volume to form in the region adjacent the spring, the adjacent walls of which are relatively vulnerable to being punctured. This is not important in some applications: but it is important when high humidity is to be avoided in proximity to articles, such as those at the bottom of the package, which are not to be used for some time in the future.

4. Moreover, economical advantage is derived from the fact that the foam which is utilized can be waste foam, i.e. nonreprocessable trimmings which are byproducts of other manufacturing processes.

ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

FIG. 1 is an exploded view of a foam-activated, positive-action, dispensing container of the invention showing thereon each of the parts of the container and their relationship one-to-the-other.

Referring to FIG. 1, it is seen that dispensing container 12 comprises a bearing surface such as base board 14, and open-ended box member 16 having a flange 17 which is to be glued or otherwise attached along the outer surfaces of base board 14. A cover 18 may be used to cover box member 16 if desired.

Inside box member 16 and resting on base board 14 opposing the open end of box member 16 are the following items reading from bottom to top:

a. resilient polymeric cellular foam biasing means 20, advantageously soft polyurethane foam such as the polyether type sold under the trade designation "UU 34 Ether" by Rogers Corporation; this biasing means is to be compressed between base board 14 and

b. a piston board 22;

c. a stack of packaged articles 23 comprising alternating divider sheets 24 and membranes 26.

Divider sheets 24 have a marginally projecting tab 25 which, when pushed through tab cutout 52 of opening 28 in box member 16, allow the sheet to be removed quickly and conveniently exposing the membrane in an easily accessible position. In practice, foam biasing means 20, acts on piston board 22 to advance stack 23 of articles to opening 28 in box member 16.

The foam specified above is of low density, i.e. about 1.5 pounds per cubic foot when not under compression. Holes 19 may be cut in it when desirable to reduce the total spring effect, and to achieve optimum distribution of the biasing force but this is usually not necessary. It has been found that the specified foam can be compressed to less than 15 percent of its original volume with a pressure which does not exceed more than about two or three times the amount of pressure necessary to achieve initial compression. Thus only slowly decaying pressure ranging from about 0.1 to 0.3 pounds per square inch is experienced as the package is emptied. It will be understood that many foam products have this characteristic and are suitable for use in forming the container according to the invention.

This device is particularly useful in packaging permeable membranes of the type used in ultrafiltration and/or reverse osmosis applications. Many of these membranes have very thin barrier layer, e.g. of about 0.1 to 5 microns in thickness; thus they must not be subject to any excessive abrasion. Moreover, many of these membranes have highly porous substrates that are easily compressed-- sometimes at pressures below 5 p.s.i.g.-- to the detriment of the performance characteristics of the membrane. Thus such membranes require a packaging means which minimizes both a risk of abrasion and excessive packaging pressure, while maintaining a convenient dispensing action.

That the package of the invention is particularly useful in such membrane packaging is evident. The foam pressurizing means is of sufficient size to distribute its relatively low force over the largest possible area, i.e. the area roughly defined by piston board 22.

Moreover, divider sheets 24 are constructed to have dimensions greater than opening 28, i.e. a relatively large diameter with respect to both membranes 26 and with respect to the opening 28 in box member 16, while the membrane articles have dimensions smaller than opening 28 and are arranged to pass through the opening. Thus when foam biasing means pushes a stack 23 to the opening 28, only the divider sheets 24 will impinge on the lower perimeters 50 of opening 28. The membrane itself will be restrained by force exerted by the entire divider sheet rather than by a narrow band of pressure about its perimeter.

The divider sheet is advantageously constructed of a light and flimsy sheet material thus a tab 25 of this divider sheet can be frictionally engaged by a finger slid over tab cutout 52. The sheet is then pulled out of the box. Very little, if any, abrasive action is exerted on the membrane by the removal of the divider sheet, because the removed divider sheet has been held near its circumference by the box and the next lower divider sheet. The smaller diameter membrane is only subject to very little, if any, abrasive action.

Although the illustrated embodiment of the invention utilizes a piston board, those skilled in the art, on reading the instant specification, will realize that this board may be dispensed with when the character of the packaged article is suitably rigid so they can act themselves as piston boards.

Moreover, those skilled in the art, on reading the instant specification, will be aware that the relatively constant dispensing force achievable with the instant invention will be of advantage when incorporated into downwardly facing dispensing devices which have heretofore had to depend to an excessive extent on frictional resistance of packaged articles to downward flow, so that they would require articles to be biased under excessive pressure when the dispenser was filled and/or allow the articles to be under too little pressure when the dispenser was nearly empty.

Claims

What is claimed is:

1. A dispensing package comprising a container having an opening, a stack disposed within said container opposing said opening, said stack including articles having dimensions smaller than said opening and arranged to pass through said opening and divider sheets interposed between adjacent articles in said stack, said divider sheets having dimensions greater than said opening the limitation, "and being constructed of a light and flimsy sheet material," and a resilient foam biasing means within said container in position to force said stack toward said opening with a marginal portion of the end divider sheet engaged by the margin of said opening.

2. A dispensing package as claimed in claim 1 wherein each divider sheet has a marginally projecting tab and said opening includes a tab cutout in registration with said tab to permit said tab to pass through said opening.

3. A dispensing package as claimed in claim 1 in which said articles are membranes of the type used in ultrafiltration or reverse osmosis.

4. A dispensing package as claimed in claim 1 in which said foam biasing means includes holes cut in it to achieve optimum distribution of said biasing force.

5. A dispensing package as claimed in claim 1 in which a piston board is interposed between said stack and said foam biasing means.