Abstract:
A container especially for use with viscous substances has both a primary opening and a supplemental opening. The primary opening is at an upper point in the container, whereby contents are extracted due to gravity, when tilting the container. A supplemental opening with removable closure is provided at a lowermost point in the container, for also extracting contents under gravity feed. The supplemental opening is preferably located at the end of a slope, causing material in the container to accumulate over the supplemental opening. Particular removable closures include plugs, tethered plugs and frangible panels.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of containers, especially for consumer products, and in particular to a bottle for viscous substances having an internal contour adapted to accumulate the viscous substance at a lowermost point in the container when upright, and a supplemental opening with a removable closure at the lowermost point for removing the accumulated viscous substance under gravity feed. 
     2. Prior Art 
     Typical containers for consumer products hav substantially-flat inside bottom contours or domed bottom contours. When such containers are nearly empty, the contents of the container are spread more or less evenly around the circumference and over a relatively large area. Surface tension and wetting effects cause a quantity of the material, especially viscous liquid material such as shampoo, to cling to the bottom of the container. Material also clings to the side walls when the container is tilted upside down in attempts to extract the contents. Frequently, users of shampoo, thick food products such as salad dressing, sauces, ketchup and similar viscous materials store the containers upside down in order to cause the viscous material to accumulate at the primary closure on the primary opening at the top of the neck of the container, e.g. bottle. Usually, the closure is a threaded cap. While such a technique is effective at extracting the contents of containers, and will allow the user to use the &#34;last drop&#34; of contents, the procedure is cumbersome. 
     Some containers for liquid products have irregular bottom contours. U.S. Pat. No. Des. 225,975 - Danjczek discloses a bottle for use as an ink well, including means defining a narrowing cross section terminating at the bottom surface along a line. The last portion of ink or the like is confined along the line at the bottom and can be extracted. The bottom forms a trough defined by the inner bottom walls. The material of course also can be extracted through the primary opening. 
     Users who desire to accumulate material in a container at a relatively confined bottom area could also employ the container of U.S. Pat. No. Des. 175,196 - Suttle. This container has a flattened side upon which the container can be rested while tilted, to thereby accumulate material at the edge of the bottom. This is effective to accumulate viscous material in a relatively smaller area and will presumably allow the user to extract a greater proportion of the material by avoiding undue wetting across a wide, flat bottom surface. However, the material still must be extracted through the primary opening and wetting of the material along the sides of the bottle as the material flows to the primary opening will make it impossible to promptly extract most or all of the material. According to known disclosures, wetting of the sides of the container is unavoidable when tilting the container, and the contents cannot be completely extracted. 
     Not all containers are flat on the inner walls of their bottoms. U.S. Pat. No. Des. 25,056 shows a bottle in which the inner contour of the bottom is domed. When this container is nearly empty, the contents will accumulate in an annular area near the side walls. Similarly, U.S. Pat. No. 4,121,103 - Calhoun, in connection with means for detecting residual contents in containers shows as alternatives both a domed container and a container with a sloping bottom. In connection with the domed bottom residual material accumulates in an annular configuration. In the sloping bottom the material accumulates at one side. Neither of these patents teaches a supplemental opening with removable closure at the lowermost point, that can be opened by the user when the contents of the container are nearly gone. Therefore the user is unable to extract the last portion of the contents because by tilting the bottle to cause material to flow to the neck of the container, and thereby allowing wetting of the sides of the bottle, complete removal of the material is precluded. 
     Some containers such as cans for cooking oil or fuels, container drums and other large volume containers often have supplemental openings for admitting air to the container to speed draining. These supplemental openings are typically located at an uppermost point in the container or at an upper point when the container is tilted for pouring. 
     According to the invention, a bottle particularly of the type used for viscous consumer products is provided with a supplemental opening with a removable closure at the bottom in the form of a plug a tethered plug or a frangible panel. The supplemental opening is disposed at a lowermost point in the container, for example at the bottom of a slope along the bottom. The inner surface of the bottom, i.e., the surface defining the bottom of the storage volume, forms a flat or curving slope leading to the supplemental opening. As the contents of the material are exhausted, the last bit of material accumulates directly over the supplemental opening. When extracting the last portion of the contents, wetting of the inner surface occurs only immediately adjacent the supplemental opening, and not over a large area of a material flow path leading from the bottom of the container along the sidewalls to the primary closure. The bottom can be configured in a flat sloping, multiple-surface-slanted or roundly-slanted configuration. The supplemental opening can be placed along the lowermost bottom edge at a sidewall or in the bottom. The bottom can be of varying thickness defining an incline leading to the supplemental opening or of uniform thickness, the bottom wall being disposed at a tilt toward the supplemental opening. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to facilitate the removal of liquids, and particularly viscous wetting substances, from containers. 
     It is also an object of the invention to minimize wetting of container inner walls as required to extract a substance from a container by tilting the container. 
     It is furthermore an object of the invention to provide an improved container without substantially increasing the cost thereof. 
     These and other objects are accomplished by a container especially for use with viscous wetting substances having both a primary opening and a supplemental opening with removable closure. The primary opening is at an upper point in the container, whereby contents can be extracted through the primary opening due to gravity flow, by tilting the container. A supplemental opening is provided at a lowermost point in the container, also for extracting contents under gravity feed, however, without tilting the container. Particularly supplemental closures include plugs, tethered plugs and frangible panels. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     There is shown in the drawings the embodiments that are presently preferred, it should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein: 
     FIG. 1 is a perspective view of a container according to the invention. 
     FIG. 2 is a partial section view showing the bottom area of the container. 
     FIG. 3 is a section view along lines 3--3 in FIG. 1. 
     FIGS. 4, 5 and 6 are section views of alternative embodiments, corresponding to FIG. 2. 
     FIG. 7 is an elevation view of the bottom portion of the container, showing a supplemental opening and as depicted in FIG. 6. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in perspective in FIG. 1, a typical container 22 such as a shampoo bottle, ketchup bottle, etc., has a primary opening 30 adjacent its upper end, adapted to receive a closure in the form of a sealing cap (not shown) for confining the contents to the container. The sealing cap may be a threadable cap attachable by means of threads 32, or may be a press fit closure or the like. In any event, the container 22 is tilted to extract the contents such that gravity causes the contents to flow out through primary opening 30 after flowing along inner wall 34 of the neck. In so doing, the contents of the container wet the inner surfaces of container walls 24, as the contents flow by gravity to the primary opening. 
     The contents of the container may be more or less viscous. If the contents are a very viscous liquid, then a substantial volume of the contents cling to the sides of walls 24 as the contents flow along the walls. Material thus fixed to the walls 24 cannot be removed by the usual gravity flow through the neck unless the user is willing to wait quite some time. According to the invention, the surface area directly exposed to wetting by contents 40 is decreased in comparison to conventional containers, as the contents 40 are exhausted because the container need not be tilted to extract the last bit of material. A sloping bottom wall 60, namely the upper surface of the bottom, defines a lowermost receptacle of limited horizontal surface area. Therefore, a confined or narrow accumulation of substance 40 occurs over supplemental opening 50, minimizing wetting. The supplemental opening 50 has a closure which may be a plug 54, for example, inserted in a hole at the lowermost portion of the container, in bottom 26. 
     Effects of viscosity and surface tension still cause a portion of contents 40 to remain on surfaces that are wetted. As the contents are nearly exhausted in a typical container, a larger and larger proportion of the remaining contents 40 are devoted to wetting the surface of the container. Moreover, as the container is tipped, the wetting of the surface can so retard material flow, and thereby reduce the rate at which the last portion of contents flow to the outlet, to cause the user to discard a container that still has some usable substance therein. 
     By sloping the bottom wall 26 and placing a supplemental opening adjacent the lowermost point, the invention allows the user to extract the contents without tilting the container and thereby without wetting the internal surfaces 36 of walls 24. The material accumulates in a reduced area 42 adjacent supplemental opening 50. In the event supplemental opening 50 is closed by a simple plug, the user simply pulls the plug out of the hole 64 in which it is resiliently engaged, or pushes the plug through to the inside of the container, free of the hole. This allows the last portion of contents to flow out through supplemental opening 50, without unnecessarily wetting any additional surface area of the container. 
     As shown in FIG. 4, the sloping bottle can be arranged such that the lowermost point occurs near the center of the container and not adjacent the sidewalls. In this embodiment, the internal surface of the container is symmetrical. At any rate, the supplemental opening 50, in this case hole 64, occurs at the lowermost point of the container. The integral contour could also be flat, however, the result of a flat configuration is an increase in the surface area wetted as the consents are extracted. 
     FIG. 4a shows an alternative embodiment in which the hole 64 is plugged by a frangible panel. A weakened frangible panel 72 is provided with an annular mounting portion 74, the latter being sealed to the container. Panel 72 and mounting 74 are preferably integral, however, they can be adhesively attached portions of different materials or the like. Similarly, flange 74 can be affixed adhesively, welded to the plastic or glass of the container, or likewise affixed in a leak-proof manner. When the user is satisfied that the container is empty, i.e., when tilting the container no longer extracts contents promptly, frangible panel 72 is broken, for example by finger pressure, while the container is upright. This allows the last portion of contents 40 to flow by force of gravity through the supplemental opening 50, without wetting the sides of the container. 
     FIG. 5 shows an alternative embodiment for sloping the inner surface of the bottom wall. A sloping thin bottom wall 66 is provided, thereby defining a cavity 58 that is higher on one side than the other. Adjacent the lowermost side, a plug 54 is resiliently received in hole 52, thereby closing the supplemental opening. Acccording to FIG. 5, the supplemental opening can be easily reclosable, the plug 54 remaining captive by means of tether 56. Tether 56 is adhesively attached at a space from hole 52, and is removable from the hole to remove the contents. If the user desires to reclose the supplemental opening, he merely pushes the plug 54 back into hole 52. 
     Typical containers in use for storage of viscous substances such as shampoo are frequently made of hard plastic, but may also be made of glass or even metal. In connection with a usual volume of 100 to 500 milliliters (3.4-17 fluid ounces), the containers are normally of flexible plastic with a thickness of 1-3 millimeters (0.04-0.1 inch). In such a container, a supplemental opening sufficient to drain the viscous substance at a reasonable rate is around 5 millimeters (0.2 inch). Of course, the particular dimensions of the opening will vary according to the viscosity and the rate of drainage required. 
     According to FIG. 6 the supplemental opening is placed at the lowermost point of the container, however, the supplemental opening is through sidewall 24 rather than through the bottom. The opening nevertheless occurs at the lowermost point. FIG. 6 also illustrates a tethered plug in which a plug 54 is permanently attached to the container by means of a tether 56, adhesively attached to the outer surface of container wall 24 at a space from the plug. Tether 56 is a resilient material, preferably the same soft rubber or plastic as plug 54, and may also be attached by means of heat welding. The tether may hav thin portions defining preferential folds. The plug may also be an integral extension of the molded bottle. 
     As shown in FIG. 7, the tether 56 is preferably of a substantial width in comparison to plug 54, thereby providing a smoothly rounded hump rather than a sharply defined projection on the container wall. This reduces the possibility of inadvertently opening the supplemental opening. The tether does not extend substantially above the surface, whereby the container can still be processed with automatic handling machines. 
     The particular shape of the inner walls and bottom can define a truncated cylinder as in FIGS. 1, 5 and 6, or other shapes can be used. A minimum surface area exposed to wetting is achieved when the container is conical, with the apex of the cone at the supplemental opening. 
     The invention having been disclosed, a number of additional variations will now occur to persons skilled in the art. Reference should be made to the appended claims rather than the foregoing specification as indicating the true scope of the invention.