Abstract:
A container, for example for a food product or the like, provides an elevating lower inner surface that may sealably support a contained food product to raise the upper surface of the food product as it is consumed. Importantly, the container avoids an extension of the elevating mechanism into the product itself, reducing problems of contamination and leakage.

Description:
CROSS-REFERENCE TO RELATED CASES 
       [0001]    This application claims the benefit of U.S. provisional application 61/376,883 filed Aug. 25, 2010 and hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to containers for food items and similar products and in particular to a container having an elevating inner wall employing an elevating mechanism that does not extend into the product or outside of the container during use. 
         [0003]    Certain food products, for example, salsa, may be enjoyed by dipping chips or the like directly into the product. For this purpose, the product may be emptied from its original container into a shallow bowl suitable for this purpose. 
         [0004]    It would be desirable to be able to dip some food products directly into the container to avoid the need for a separate dish and to permit the casual enjoyment of the product in a variety of different environments including those where a separate dish is impractical or inappropriate. Dipping products directly into the container works relatively well when the container is full, but it can be difficult or impossible as the food product is consumed and its upper surface drops into the container. This problem can be lessened by the use of extremely shallow containers; however, such containers can be impractical in the stream of commerce and unattractive to the end consumer. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a container for salsa or the like that has an elevating lower inner surface that may sealably support a contained food product to raise the upper surface of the food product as it is consumed. Importantly, the container avoids an extension of the elevating mechanism into the product itself, reducing problems of contamination and leakage. Further, the mechanism is compact and wholly contained within the container to provide practical shipping and storage of the container. 
         [0006]    Specifically, the present invention may provide a container having a base surrounded by substantially rigid upstanding outer sidewalls terminating at an upper lip for receiving a lid, the base movably held within the sidewalls to move upward therein. An inner collapsible sidewall has an upper edge elevationally fixed with respect to the upper lip and a lower edge elevationally movable with the base. 
         [0007]    It is thus an object of at least one embodiment of the invention to provide a packaging container that simplifies dispensing amorphous or fluid-like materials by allowing the product to be elevated within the container as it is consumed. 
         [0008]    The inner collapsible sidewalls may comprise a set of telescoping rings. 
         [0009]    It is thus an object of at least one embodiment of the invention to provide for an inner wall system that may protect an elevating mechanism from contact with the contained product. 
         [0010]    The container may further include a set of inter-engaging thread elements having a first portion attached to the base so that relative rotation of the inter-engaging thread elements causes upward movement of the base. 
         [0011]    It is thus an object of at least one embodiment of the invention to provide a precise elevational mechanism that is resistant to accidental displacement. The thread mechanism allows precise elevational control while offering resistance against unintended elevational changes by normal friction amplified by the mechanical advantage of the thread. 
         [0012]    A second portion of the inter-engaging thread elements may be a helical groove attached to an inner wall of the upstanding outer sidewalls so that rotation of the base causes it to climb upward within the outer sidewalls. 
         [0013]    It is thus an object of at least one embodiment of the invention to reduce the necessary material for fabrication of the container by integrating the threads into the outer container walls. 
         [0014]    The container may further include a knob rotatable about a vertical axis and communicating with the base to rotate the base with rotation of the knob. 
         [0015]    It is thus an object of at least one embodiment of the invention to provide a simple and convenient control surface for the consumer. 
         [0016]    The knob may provide an outer base to the container. 
         [0017]    It is thus an object of at least one embodiment of the invention to provide a control surface for elevating the base that may be simply integrated into the container outer surface. 
         [0018]    The knob may include upwardly extending pins positioned between the upstanding outer sidewalls and the inner collapsible sidewalls to be received within channels in the base to cause rotation of the base while permitting separation of the base and knob with rotation of the knob. 
         [0019]    It is thus an object of at least one embodiment of the invention to provide a simple mechanism that provides a strong communication of torque between the knob and base while allowing freedom of separation between the two. 
         [0020]    These particular objects and advantages may apply to only some embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective view of a salsa container constructed per the present invention as may be used for dipping salsa directly from the container; 
           [0022]      FIG. 2  is an elevational cross-section through a first embodiment of the invention showing a false bottom that may be pressed upward through a hole in the actual bottom as product is consumed; 
           [0023]      FIG. 3  is a fragmentary detail view of  FIG. 2  showing a ratchet mechanism incorporated into the walls of the container to hold the bottom in place as it is pressed upward; 
           [0024]      FIG. 4  is an elevational cross-section of a second embodiment of the invention providing an elevating screw formed from a compressed helical spring that may be uncoiled by rotation of the base of the container; 
           [0025]      FIG. 5  is a perspective view of the container of  FIG. 4  showing rotation of the base to uncoil the compressed spring; 
           [0026]      FIG. 6  is a fragmentary cross-section of a portion of the base holding the compressed spring showing the uncoiling process; 
           [0027]      FIG. 7  is a perspective view of a telescoping shroud that may be used to cover the spring mechanism or the opening of the above embodiments, the shroud shown in an extended form; 
           [0028]      FIG. 8  is a figure similar to that of  FIG. 7  showing the shroud in collapsed form; 
           [0029]      FIG. 9  is an elevational, cross-sectional view of a third embodiment of the invention employing an inflatable bladder and pump to elevate a false bottom; 
           [0030]      FIG. 10  is a bottom plan view of the container of  FIG. 9  showing the offsetting of the pump from the bladder; 
           [0031]      FIG. 11  is a block diagram of check valves used between the pump and bladder; 
           [0032]      FIG. 12  is an elevational cross-section through a fourth embodiment of the invention showing a false bottom engaging internal threads on the container; 
           [0033]      FIG. 13  is a bottom plan view of the container of  FIG. 12 ; 
           [0034]      FIG. 14  is a fragmentary elevational cross-section similar to  FIG. 4  showing an alternative embodiment of the mechanism of  FIG. 4 ; 
           [0035]      FIG. 15  is an elevational cross-section of a fifth embodiment of the invention providing an inner telescoping wall separating contained product from a threaded engagement between the bottom and inner wall of the container showing the container in a full state; 
           [0036]      FIG. 16  is a fragmentary version of  FIG. 15  showing the container in the partially emptied state with the base elevated; and 
           [0037]      FIG. 17  is an exploded perspective view of the container of the fifth embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0038]    Referring now to  FIG. 1 , a container  10  of the present invention may provide an outer wall  12  defining, for example, a cylindrical inner volume  14  holding a food product  16  such as salsa accessible through an open end  18 . The open end  18  may be covered by a removable lid  20 , for example, by means of a threaded engagement between threads on the open end  18  and corresponding inner threads on the lid  20  as understood in the art. The lid  20  may include a gasket to sealably hold the food products  16  in the container  10  when the lid  20  is tightened. 
         [0039]    The container  10  may rest on a bottom wall  22 , for example, providing a planar surface for support against a table or the like. The food products  16  may be exposed through the open end  18  of the container  10  for dipping with chips  23  or the like. 
         [0040]    Referring now to  FIG. 2 , in a first embodiment the bottom wall  22  may have an open central aperture  24  through which, for example, a user&#39;s thumb  27  may be inserted to push upward against a false bottom  26  positioned above the bottom wall  22  and extending parallel to the bottom wall  22  fully across the inner volume  14  to sealably separate the food products  16  from a space  29  beneath the false bottom  26 . The false bottom  26  may, for example, be constructed of a resilient plastic having downwardly extending stiffening fins  28  to preserve its planar configuration and downwardly extending sealing flanges  30  resiliently biased outward to press against the inner surface of the outer walls  12  to prevent leakage past the false bottom  26 . 
         [0041]    Referring to  FIG. 3 , in one embodiment the inner surfaces of the walls  12  may include serrated ratchet teeth  32  that may engage the downwardly extending flanges  30  in the manner of a pawl on a ratchet so as to prevent downward movement of the false bottom  26  once it has been pressed upward. 
         [0042]    Referring now to  FIG. 4 , in an alternative embodiment the false bottom  26  may have upwardly extending sealing flanges  30 ′ to be pressed outward with downward pressure by the food products  16 . False bottom  26  may be supported by an upper end of a coiled helical spring  34  held in partial coiled compression within a pocket  36  formed in a rotatable bottom wall  22 ′. The pocket  36  includes a horizontal peg  40  extending radially through the axis of the spring  34  to hold it in compression within the pocket  36 . 
         [0043]    Referring to  FIGS. 5 and 6 , rotation of the bottom wall  22 ′ with respect to the upward wall  12  causes a retaining peg  40  to rotate with respect to the spring  34  to uncoil a portion of the spring  34  compressed within the pocket releasing it into an uncoiled portion  44  extending upward from the pocket  36  to press upward on the false bottom  26 . The spring  34  thereby provides a collapsible lead screw lifting the false bottom  26  upward. Yet unlike a lead screw, the spring  34  is collapsed in the pocket  36  as not to extend into the products  16  or beneath the bottom wall  22 ′. An upper portion of the spring  34  may be retained against rotation when the bottom wall  22  is rotated by a corresponding notch  46  in the bottom of the false bottom  26 ′. 
         [0044]    Referring now to  FIG. 7 , the spring  34  and pocket  36  of the embodiment of  FIGS. 4-6  or the aperture  24  of the embodiment of  FIG. 2  may be covered by a telescoping shroud  50  to further separate the mechanism or user&#39;s digits from the food products  16 . The shroud  50  may comprise a set of concentric rings with vertical walls having radially inward upper lips and radial outward lower lips that serve to connect them in full extension to their inner and outer rings. Thus the shroud  50  may collapse fully as shown in  FIG. 8  to the height of one ring and extend as shown in  FIG. 7  to the combined heights of the rings. 
         [0045]    Referring to  FIG. 9 , in an alternative embodiment, the false bottom  26  may be elevated by means of a bellows-shaped inflatable bladder  52  that may collapse when uninflated and when inflated may exert an upward force on the false bottom  26 . Inflation may be provided by means of a press bulb  56  retained in a cavity  58  beneath the bottom wall  22 . Referring to  FIGS. 10 and 11  as well as  FIG. 9 , the press bulb  56  may connect to the bladder  52  through a check valve  59  leading to an inlet port  60  of the bladder  52 . The check valve  59  may provide for one-way passage of airflow from the ambient air into the press bulb  56  and then a one-way passage of air from the press bulb  56  through the inlet port  60  to the bladder  52 . A release valve (not shown) may also be provided to permit deflation of the bladder  52   
         [0046]    Referring now to  FIG. 12 , in an alternative embodiment, the false bottom  26  may provide for an outer ring-shaped flange  62  conforming generally to the inner surface of the outer walls  12  of the container  10  in diameter and having outwardly exposed threads  64  engaging corresponding inwardly facing threads  66  on the inner surface of the wall  12 . A gripping flange  68  extending downward from the lower surface of the false bottom  26  may provide purchased for the user&#39;s thumb and fingers to allow the false bottom  26  to be rotated upward to raise the false bottom  26  by its climbing on the thread  66 . The gripping flange  68  may have beveled surfaces to promote only proper rotation of the gripping flange  68  in a direction that would provide for elevation of the false bottom  26 . 
         [0047]    Referring now to  FIG. 14 , an alternative version of the embodiment of  FIG. 4 , described above, may provide for a fixed (non-rotatable bottom wall  22 ′) having a central aperture  70  allowing lips  72  of the tubular pocket  36  formed in the rotatable bottom wall  22  to extend upward therethrough. The rotatable bottom wall  22  abuts the lower surface of the non-rotatable bottom wall  22 ′. The lips  72  may be retained by a C-clip  74  or the like engaging a groove in the outer periphery of the lips  72  and sliding against an upper surface of the non-retaining wall  22 ′. In this case, the retaining peg  40  may be attached to the non-rotatable bottom wall  22 ′ eliminating the need for the spring  34  to be retained against rotation by the bottom surface of the false bottom  26  but allowing the spring  34  to be rotationally fixed to the pocket  36  to turn therewith. It will be understood that this version easily permits the container to be a non-cylindrical shape such as an oval or rectangul in cross-section. 
         [0048]    Referring now to  FIG. 15 , an alternative version of the embodiment of  FIG. 12 , described above, may provide a means for elevating the false bottom  26  remote from the false bottom  26 . In this embodiment, the outer wall  12  is formed independently of the bottom wall  22  so that the bottom wall  22  may rotate in relation to the outer wall  12 . The bottom wall  22  is constrained against vertical motion by entering engagement of a peripheral channel  77  extending radially inward around the bottom wall as engaged by flanges  81  extending inwardly from the lower edge of the outer walls  12 . The inwardly extending flanges  81  separate the bottom wall into an outer portion that may be grasped by the user for rotation and an inner portion inside the container. 
         [0049]    The portion of the bottom wall  22  inside the container has attached two vertically-extending struts  80 , attached to the bottom wall  22  at diametrically opposed points separated by a distance less than the diameter of the outer wall  12  but greater than the diameter of a top-most cylindrical nesting ring  82 , to be described in greater detail later. The vertically-extending struts  80  may terminate before reaching the top lip  76  of the container  10  or may be attached to the top lip  76 , so long as the top lip  76  is rotationally independent from the outer wall  12 . 
         [0050]    The false bottom  26  is formed with two apertures  79  through which the vertically-extending struts  80  extend, connecting the false bottom  26  to the bottom wall  22  such that the false bottom  26  is rotationally engaged with the bottom wall  22  but remains elevationally independent. 
         [0051]    The false bottom  26  has a threaded exterior wall  78  that engages with the corresponding thread  66  of the outer wall  12 ; thus, when the false bottom  26  rotates in relation to the outer wall  12 , the false bottom  26  is moved upward. The user may rotate the false bottom  26  in relation to the outer wall  12  without needing access to the false bottom  26  because it is rotationally coupled to the bottom wall  22  by the struts  80 . Alternatively, the user may grip the bottom wall  22 , keeping it stationary, and rotate the outer wall  12  to achieve the intended elevation. 
         [0052]    The false bottom  26  is, in this embodiment, permanently attached to the smallest of a set of cylindrical nesting rings  82 . Collectively, the cylindrical nesting rings  82  form the exterior wall of the inner volume  14  containing the food product  16 , and when the smallest of the cylindrical nesting rings  82  is so attached to the false bottom  26 , a telescoping cup  84  is formed. The nesting ring  82  of greatest diameter may include the top lip  76 . 
         [0053]    Referring now to  FIG. 16 , as the false bottom  26  is elevated, each cylindrical nesting ring  82  may remain stationary until the false bottom  26  is level with the bottom of the cylindrical nesting ring  82 , at which point the ring  82  is pushed upward along with the false bottom  26 . When the false bottom  26  is positioned at a distance from the top lip  76  equal to the height of the cylindrical nesting rings  82 , the container  10  now has an interior volume  14 ′ defined by the diameter and height of the smallest nesting ring  82 . 
         [0054]    Referring now to  FIG. 17 , the outer wall  12  as shown may rotate independently of the other components. Each of the cylindrical nesting rings  82 , except for the topmost, moves up and down along with the false bottom  26 . The false bottom  26  travels along the vertically extending struts  80 . When assembled, the topmost cylindrical nesting ring  82  and the bottom wall  22  remain a fixed distance from each other and neither rotates with respect to the other. 
         [0055]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0056]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0057]    Various features of the invention are set forth in the following claims. It should be understood that the invention is not limited in its application to the details of construction and arrangements of the components set forth herein. The invention is capable of other embodiments and of being practiced or carried out in various ways. Variations and modifications of the foregoing are within the scope of the present invention. It also being understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention.