Abstract:
The invention is a steam-table pan formed of drawn metal sheet, the pan having a pinch-gripping bead including a gripping-skirt which is configured and vertically dimensioned for pinch-gripping of the bead with an adult&#39;s fingers to raise the pan from the steam table. The configuration of the steam-table pan provides substantially enhanced deformation resistance without a corresponding increase in thickness of the metal sheet.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of currently pending patent application Ser. No. 11/760,572, filed on Jun. 8, 2007, which is a continuation of abandoned patent application Ser. No. 11/623,557, filed Jan. 16, 2007. The contents of both applications are incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to food pans, particularly to food pans for use in buffet and/or steam tables (referred to collectively herein as “steam tables”). 
       BACKGROUND OF THE INVENTION 
       [0003]    In the food service industry, foods are often served on buffet tables designed to maintain desired temperatures for cold or hot foods. The desired temperature maintenance is provided by cold air or hot steam (and/or cold or hot water) within the chamber of a steam table. Such chamber, of course, is immediately beneath the top wall of the steam table, and the top wall has openings to receive special food-serving pans such that the walls of the pan (sidewalls and bottom wall) are fully exposed to the chamber when the pan is in place on the steam table. 
         [0004]    Steam-table pans have a lip-portion protruding outwardly from the upper edges of the sidewalls, and when the pan is in position on the steam table, it is supported by the engagement of its lip-portion with the top of the steam-table top wall. Thus, the food in the pan is kept at the desired temperature (or, more specifically, within a desired temperature range, by the fluid (air, steam and/or liquid water) in contact with the pan. Of course, it is important that the pan or pans on the steam table sufficiently close the chamber to prevent undesired heat losses or gains. The “seal” between the pan and the table top is provided by the contact of the lip-portion of the pan with the top of the steam table. 
         [0005]    In use, steam-table pans need to be repeatedly removed from the steam table for refilling, replacement, cleaning and other reasons. Steam-table pan configurations have made it difficult to remove the pans from steam tables. Typically, lifting is accomplished by wedging a finger, utensil or other tool under the lip-portion to begin lifting the pan. Such actions may be rather dangerous to a person trying to lift the pan from the table since uncontrolled escape of steam may burn the person&#39;s hand. It is rather common practice for personnel to attempt to facilitate this initial lifting step by intentionally and permanently deforming the lip-portion in one or more places to provide a gripping place or to facilitate a wedging step. Such lip deformation breaks the “seal” between the pan and the table top, which results in harmful heat losses or gains. This can greatly decrease steam-table efficiency by raising the use of power for maintaining the desired temperature, not to mention the fact that the appearance of the pan is ruined. There is a need for a steam-table pan which is easily removable from the steam table and which, when the pan is in place, reliably closes the chamber to prevent energy inefficiency throughout the life of the pan. 
         [0006]    These problems are so longstanding and commonplace that some inventive efforts have been made to deal with such problems. One of the existing solutions to the problem of raising a pan out of the steam table involves a “ramping” configuration which involves a rather drastic change in pan geometry which allows a pushing or pulling action on the inside surface of a pan sidewall against tile edge of a steam-table opening to cause some initial raising of the pan, thereby to facilitate lifting and removal. 
         [0007]    Such “ramping” pans, which are understandably quite expensive, have a number of disadvantages stemming from their unusual configurations. 
         [0008]    Among the problems are a resulting loss in pail capacity because of the more-inward nature of the configuration due to the ramping features. Also, the ramping configuration is such that it may increase the possibility of spilling pan contents due to the less-vertical nature of the pan sidewalls near the lip-portion. Furthermore, the non-standard shapes of such “ramping” pans mean that they are not readily stacked with users&#39; existing inventories of steam-table pans of typical configurations. A further disadvantage of such “ramping” pans is that because of their non-typical configurations they typically require that accessories used with steam-table pans, such as wire grates, false bottoms and even some utensils, cannot be of standard shapes and sizes. For example, wire grates and false bottoms may have to be smaller than standard wire grates and false bottoms; and serving scoops may require unusual, non-standard shapes because scoops of standard round-edge shapes will not completely engage with bottom and side corners of the pans. The requirement of special accessories tends to significantly increase the total cost to an institution of using such “ramping” pans. 
         [0009]    Still another problem is that the pushing or pulling action on the inside surfaces of such “ramping” pans typically involves manual contact with wall surfaces which are or have been exposed to food. This may raise concerns related to sanitation, whether or not personnel use gloves, and also creates finger/glove cleanliness issues. Also related to cleanliness is the fact that such “ramping” pans, with their significantly increased surface irregularities, are more difficult to wash. Wiping action on inside surfaces must give additional attention to such irregularities in order to avoid food residues from remaining after washing operations. 
         [0010]    Thus, there is a need for a steam-table pan which provides easy removability from the steam table without giving rise to aforementioned problems associated with pans having the aforementioned “ramping” features. 
         [0011]    Another problem with certain steam-table pans of the prior art arises because such pans frequently moved around for different purposes in fast-moving institutional kitchen operations. Such movements and handling on many occasions can result in pans dropping and receiving significant impact damage on their lip-portions. In addition, in kitchen storage areas various heavy objects may fall on steam-table pans causing deformation of the lip-portions. Any such deformations tend to be permanent, and cause the same problems as the intentional lip-portion distortions mentioned above. Pan deformation obviously limits useful pan life, giving rise to replacement costs. Thus, it is highly desirable to have long-lasting, sturdy pan construction. There is a need in the industry for steam-table pans with improved edge-portion strength. 
         [0012]    As is seen from the above reference to deformation caused by unintentional dropping or banging about of steam-table pans, deformation of pan edge portions is a significant problem in the field of steam-table pans. Steam-table pans, although typically formed of drawn metal sheet such as 22-gauge or even 20-gauge steel, have edge portions that are too easily deformed. There is a need in the steam-table industry for pans with much greater resistance to edge deformation. 
         [0013]    In summary, there is a need for an improved steam-table pan which is easily liftable from steam tables and which overcomes all of the aforementioned problems. 
       OBJECTS OF THE INVENTION 
       [0014]    It is an object of the invention to provide an improved steam-table pan overcoming some of the problems and shortcomings of the prior art, including those referred to above. 
         [0015]    Another object of the invention is to provide a steam-table pan which is easily removable from the steam table simply by hand gripping and lifting. 
         [0016]    Another object of the invention is to provide a steam-table pan with such easy removal characteristic and which, when the pan is in place, reliably closes the chamber to prevent energy inefficiency throughout the life of the pan. 
         [0017]    Yet another object of the invention is to provide a steam-table pan with improved lip-portion strength for long-lasting, sturdy pan construction. 
         [0018]    Another object of the invention is to provide a steam-table pan which is designed for easy removability from the steam table without sacrifice of pan capacity. 
         [0019]    Another object of the invention is to provide a steam-table pan which is designed for easy removability from the steam table without increased possibility of spillage. 
         [0020]    Yet another object of the invention is to provide a steam-table pan which is designed for easy removability, yet allows use of accessories of typical sizes. 
         [0021]    Another object of the invention is to provide a steam-table pan which is easily removable from the steam table and can be readily stacked with users&#39; existing inventories of pans. 
         [0022]    Still another object of the invention is to provide a steam-table pan which is easily removable from the steam table and minimizes pan-washing problems. 
         [0023]    How these and other objects are accomplished will become apparent from the following descriptions and the drawings. 
       SUMMARY OF THE INVENTION 
       [0024]    This invention, which will be described in detail below, is an improvement in steam-table pans formed of drawn metal sheet of the type including (a) a surrounding wall that is dimensioned for insertion in an opening in the top of a steam table and has an upper edge and (b) a lip-portion integral with the upper edge and protruding outwardly therefrom to overlap the steam-table top. 
         [0025]    The inventive steam-table pan has a pinch-gripping bead which includes the normal upper portion of the surrounding wall, the lip-portion, and a gripping-skirt, now described. The gripping-skirt is substantially vertical and integral with the lip-portion, extends downwardly from the lip-portion to rest on the steam-table top, and is configured and vertically dimensioned for pinch-gripping of the bead with an adult&#39;s fingers to raise the pan from the steam table. The fact that the gripping-skirt is configured and vertically dimensioned for pinch-gripping of the bead with an adult&#39;s fingers to raise the pan from the steam table means that it is such that an adult can pinch-grip the bead and lift the pan from its fully-engaged position on the steam table. The term “pinch-gripping” means firmly holding the inner surface of the upper portion of the surrounding wall and the gripping-skirt between his or her (1) thumb and (2) index and/or middle finger(s). Preferably, the gripping-skirt is vertically dimensioned for engagement of such gripping-skirt by a mid-portion of an adult&#39;s thumb to raise the pan from the steam table. 
         [0026]    In highly preferred embodiments, the gripping-skirt is configured such that it extends vertically downwardly from the lip-portion by a distance greater than the horizontal dimension of the lip-portion between the upper edge of the pan wall and the gripping-skirt. The vertical dimension of the gripping-skirt is preferably at least about ½ inch. 
         [0027]    It is further preferred that the gripping-skirt be substantially parallel to the surrounding wall. The term “substantially parallel” as used herein does not require a true parallel relationship between the gripping-skirt and upper portion of the surrounding wall. However, it is preferable that they at least partially extend in the same direction, resulting in substantially equidistant relationships of horizontally-spaced planar portions to facilitate a secure grip of the pinch-gripping bead between an adult&#39;s fingers for pan-lifting purposes. 
         [0028]    An important aspect of the present invention is that the configuration of the pinch-gripping bead provides substantially enhanced deformation resistance in pan-edge portions without a corresponding increase in thickness of the metal sheet (decrease in the gauge of the sheet metal). The necessary substantial vertical dimension of the gripping-skirt serves as vertical reinforcement of edge region of the pan. In the prior art, pan-edge distortion, particularly in corner areas, whether due to intentional bending or unintentional dropping or impact, was not readily resisted by the nature of the pan-edge area. However, edge regions of the pan of this invention, including deformation-susceptible corner areas, have significantly greater resistance to distortion than is seen in any prior art steam-table pans of similar metal gauge. 
         [0029]    The inventors and their associates commissioned impact/drop testing on the inventive steam-table pan. Two types of tests were performed, one involving load testing and the other involving impact/drop testing. The independent testing showed that corner portion of the edge areas of the pans of this invention are far stronger than for certain prior pans. Such improved strength does not come by virtue of thicker metal, but by virtue of the unique edge features of this invention. 
         [0030]    In referring to drop-test results, comparisons are always made between full-size pans of similar metal gauge, or between half-size pans of similar metal gauge. (Full-size pans typically have a length of about 20.75 inches and a width of 12.75 inches, while half-size pans typically have the same width but a length of 10.375 inches, in each case regardless of pan depth. The term “pan size” as used herein refers to the width and length of a steam-table pan, which of course relates to its insertion into a steam table.) 
         [0031]    This invention provides dramatic improvement in pan strength. In fact, in corner drop-tests, for half-size pans the configuration of the pinch-gripping bead surprisingly exhibits deformation resistance at least about twenty times greater than for old-style standard steam-table pans of similar gauge. And, for half-size pans the configuration of the pinch-gripping bead surprisingly exhibits deformation resistance which is about a full order of magnitude greater than is exhibited even for the old-style ramping-type steam-table pans (referred to above) of similar gauge. For full-size pans, which by industry standards have a lip-portion with horizontal dimension greater then that for half-size pans, the inventive configuration exhibits deformation resistance of at least about four times greater than for full-size old-style steam-table pans of similar gauge. 
         [0032]    The advantage of dramatically improved strength provided by this invention can, of course, also mean that acceptable distortion resistance may be achieved even with some cost-saving reductions in material thickness. 
         [0033]    Manufacturing of the steam-table pan with the pinch-gripping bead involves a variation from the normal production process, namely, the adding of an extra metal drawing step to achieve a vertical dimension of the bead that permits pinch-gripping of the bead with an adult&#39;s fingers to raise the pan from the steam table. 
         [0034]    The steam-table pan also includes a bottom-wall, bottom corners that are integral with the surrounding wall and the bottom-wall, such bottom-corners being shaped with common partial circular cross-sections. The surrounding wall includes the sidewalls and also side-corners which are integral with adjacent pairs of sidewalls, the side-corners being shaped with the common partial circular cross-sections just mentioned. Such common partial circular cross-sections facilitates full engagement of all corners by industry-standard circular-edged utensils. 
         [0035]    The term “industry-standard circular-edged utensils” means utensils (e.g., serving spoons, loons, scoops or dishers) having scooping radii of commonly used existing utensils. For example, scooping radii for some common utensils of different capacities are 1.23 inches, 1.56 inches, 1.66 inches, 2.00 inches and 2.22 inches. The common partial circular cross-sections of the bottom-corners and side-corners are shaped to accommodate such utensils; no special utensils are needed for buyers/users of the inventive steam-table pans. 
         [0036]    The term “old-style standard steam-table pan” refers to the well-known drawn-metal steam-table pans which each include (1) a surrounding wall dimensioned for insertion in an opening in the top of a steam table, (2) a wall upper edge, and (3) a lip-portion integral with the upper edge and protruding outwardly therefrom to overlap the steam-table top, and which have either no downwardly extending portion whatsoever at the distal edge of the lip-portion or, at most, a downwardly extending portion which is insufficient (in any configuration) for purposes of horizontal pinch-gripping of the upper portion of the pan—i.e., insufficient for firmly holding the inner surface of the upper portion of the surrounding wall and the downwardly extending portion between a person&#39;s thumb and index and/or middle finger(s). Two typical examples of old-style standard steam-table pans are illustrated in fragmentary schematic  FIGS. 5 and 6 , which are labeled “Prior Art.” The prior art pans illustrated each have a pan depth of about two and a half inches, one of the industry standard depths. 
         [0037]    The term “old-style ramping-type steam-table pan” refers to drawn-metal pans of the sort disclosed in U.S. Pat. No. 6,415,945, which each include a surrounding wall having a sloping upper edge portion, a lip-portion integral with the upper edge and protruding outwardly therefrom to overlap the steam-table top, and an outwardly sloping downward portion with a vertical dimension of about 0.1875 inch. Pinch-gripping of such upper edge portion is not possible. A typical old-style ramping type steam-table pan is illustrated in  FIG. 7 , which is like  FIG. 21A  of the &#39;945 patent. 
         [0038]    The steam-table pan of this invention overcomes the problems described above, and provides important advantages for institutional food operations. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0039]      FIG. 1  is a perspective view of a steam-table pan approximately two and a half inch deep having a pinch-gripping bead of this invention. 
           [0040]      FIG. 2  is an enlarged fragmentary sectional view taken along section  2 - 2  as indicated in  FIG. 1 . 
           [0041]      FIG. 3  is a sectional view like on  FIG. 2  and showing pinch-gripping action by adult&#39;s fingers. 
           [0042]      FIG. 4  is a perspective view of another embodiment of a steam-table pan approximately four inches deep that has a pinch-gripping bead in accordance with this invention. 
           [0043]      FIG. 5  is a fragmentary sectional view of one example of an old-style standard steam-table pan. 
           [0044]      FIG. 6  is a fragmentary sectional view of another example of an old-style standard steam-table pan. 
           [0045]      FIG. 7  is a fragmentary sectional view of an example of an old-style ramping-type steam-table pan. 
           [0046]      FIG. 8  is a fragmentary sectional view of an embodiment of the inventive pan which, like the old-style steam-table pans of  FIG. 5-7 , has a depth of two and a half inches and is shown to scale, as are  FIGS. 5-7 . 
           [0047]      FIG. 9  is a side-by-side photographic comparison showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 1  (the pan on the right) and an old-style standard steam-table pan (the pan on the left), each pan having a depth of approximately 2.5 inches. 
           [0048]      FIG. 9A  is a similar side-by-side photographic comparison showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 4  (the pan on the right) and an old-style standard steam-table pan (the pan on the left), each pan having a depth of approximately 4 inches. 
           [0049]      FIG. 10  is another side-by-side photographic comparison, this one showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 1  (the pan on the right) and an old-style ramping-type steam-table pan (the pan on the left), each pan having a depth of approximately 2.5 inches. 
           [0050]      FIG. 10A  is a similar side-by-side photographic comparison showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 4  (the pan on the right) and an old-style ramping-type steam-table pan (the pan on the left), each pan having a depth of approximately 4 inches. 
           [0051]      FIG. 11  is yet another side-by-side photographic comparison, this one showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 1  (the pan on the right) and an old-style standard steam-table pan with a rim as disclosed in U.S. Pat. No. D333,944 (the pan on the left), each pan having a depth of approximately 2.5 inches. 
           [0052]      FIG. 11A  is a similar side-by-side photographic comparison showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 4  (the pan on the right) and an old-style standard steam-table pan with a rim as disclosed in U.S. Pat. No. D333,944 (the pan on the left), each pan having a depth of approximately 4 inches. 
           [0053]      FIG. 12  is still another side-by-side photographic comparison showing the difference in deformation resistance between the inventive steam-table pan of  FIG. 4  (the pan on the right) and an old-style standard steam-table pan of the sort having an offset wall shoulder (the pan on the left), each pan having a depth of approximately 4 inches. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0054]    The drawings show an improved steam-table pan  10  of the type including (a) a surrounding wall  20  that is dimensioned for insertion in an opening in the top  12  of a steam table and has an upper edge  21  and (b) a lip-portion  22  integral with upper edge  21  and protruding outwardly therefrom to overlap steam-table top  12 . 
         [0055]    Steam-table pan  10  has a pinch-gripping bead  30  which includes the normal upper portion  24  of surrounding wall  20 , lip-portion  22 , and a gripping-skirt  32 . As seen in the figures, gripping-skirt  32  is integral with lip-portion  22 , extends downwardly from lip-portion  22  to rest on steam-table top  12 , and is configured and vertically dimensioned for pinch-gripping of bead  30  with an adult&#39;s fingers  14  to raise pan  10  from the steam table. 
         [0056]    As best shown in  FIG. 2 , gripping-skirt  32  has a vertical dimension V which facilitates engagement therewith by the mid-portion of an adult&#39;s thumb  14  to raise the pan from the steam table.  FIG. 3  illustrates adult&#39;s fingers  14  and  15  pinch-gripping the inner surface of upper portion  21  of surrounding wall  20  and gripping-skirt  32  between hisser thumb  14  and index finger  15 .  FIG. 2  best shows gripping-skirt  32  configured such that it extends vertically downwardly from lip-portion  22  by a distance V which is greater than a distance H on which lip-portion  22  extends horizontally outwardly from upper edge  21  of surrounding wall  20 . 
         [0057]      FIGS. 2 and 3  show gripping-skirt  32  being substantially parallel to surrounding wall  20 . Gripping-skirt  32  is substantially vertical. 
         [0058]    Steam-table pan  10  also includes a bottom-wall  23 , bottom corners  29  that are integral with surrounding wall  20  and bottom-wall  23 , such bottom-corners  29  being shaped with common partial circular cross-sections with a radius R, as shown in  FIG. 2 . Surrounding wall  20  includes sidewalls  26  and also side-corners  25  which are integral with adjacent pairs of sidewalls  26 , side-corners  25  being shaped with the common partial circular cross-sections with radius R. 
         [0059]    In pan  10 A, shown in  FIG. 4 , surrounding wall  20  includes a plurality of sidewalls  26  extending between corners  25  integral with adjacent sidewalls  26 . Surrounding wall  20  further has anti-jam wall-portions  40  to prevent jamming of multiple pans  10 A stacked together. As is also seen from  FIG. 4 , each anti-jam wall-portion  40  is off-planar with respect to its respective sidewall  26 . 
         [0060]    The old-style standard steam-table pan  50  shown to scale in  FIG. 5  includes a lip-portion  51  overlapping the steam-table top  12 . Pan  50  does not have any downwardly extending portion whatsoever at the distal edge of the lip-portion  51 . The old-style standard steam-table pan  60  of  FIG. 6  is similar to pan  50  except that pan  60  has a lip-portion  61  and a downwardly extending portion  62 , which is insufficient for purposes of horizontal pinch-gripping. 
         [0061]    The old-style ramping-type steam-table pan  70  of  FIG. 7  includes a surrounding wall  71  having a sloping tipper edge portion  72 , a lip-portion  73  integral with the tipper edge  72  and protruding outwardly therefrom to overlap the steam-table top  79 , and an outwardly sloping downward portion  74  with a vertical dimension V 70  of about 0.1875 inch. Horizontal pinch-gripping is not possible with pan  70 . Indeed, prior art pan  70  has extensive extra pan-raising features which are unnecessary in steam-table pans in accordance with the present invention. 
         [0062]      FIGS. 9-12  illustrate the dramatic increase in deformation resistance of corner areas of pans  10  and  10 A. As indicated above, pan  10 A is similar in structure to inventive pan  10  but for the fact that pan  10 A has a depth of 4 inches (rather than 2.5 inches as pan  10 ) and includes anti-jam wall-portion  40 . The illustrated pans were tested using a 7-pound weight in the drop testings shown in  FIGS. 9A ,  10 A,  11 A and  12  and a 9.2-pound weight in the drop testings shown in  FIGS. 9 ,  10  and  11 , with both weights being dropped from a 36-inch height directly onto the corner areas of the pans being tested. These figures show the great improvements in deformation resistance provided by this invention. All pans tested were 22-gauge drawn steel pans. 
         [0063]    The side-by-side comparisons show greater or lesser amounts of substantial problematic deformation of the corner regions of the various old-style steam-table pans, and little or no visible deformation of the corner regions of the pans of this invention. Accurate measurements of deformation are the basis for quantitatively showing the great improvement in deformation resistance. 
         [0064]    While the principles of the invention have been shown and described in connection with specific embodiments, it is to be understood that such embodiments are by way of example and are not limiting.