Patent Abstract:
The invention involves an improved cooking system of the type having a cooking vessel with watertight lower portion of a concave interior, having side walls generally upwardly extending from a bottom. The improvement is the addition of an annular, substantially hemi-toroidal insert. The insert is dimensioned to engage an inner surface of the side walls thereby removably supporting the insert within the cooking vessel remote from the bottom. There is a central opening in the middle of the insert, above the bottom of the vessel, whereby the bottom of the vessel may be accessed. In this way, utensils may be employed to manipulate the food cooking in the bottom of the pot or wok, ingredients may be added to the food cooking in the bottom of the pot or wok, water may be added to the bottom of the pot or wok, etc.

Full Description:
FIELD OF THE INVENTION 
     The invention relates generally to cooking vessels and more particularly to inserts for cooking vessels. 
     BACKGROUND OF THE INVENTION 
     Cooking techniques are ancient and require little exposition here other than: heat, provided by a flame or other heating element, is directed to a vessel, most typically made of metal, whereby the heat transmitted from the heat source is conducted through the metal to the food. It is necessary that the item being cooked contain some moisture in order to avoid burning. Food items not containing sufficient moisture are generally boiled in water or placed in the vessel with another food item having a greater moisture content (e.g., sauces, pastes, soups, fats, etc.). Some of the disadvantages of cooking food in water are that the food items lose flavor to the water, vitamins contained within the food items leach out into the water and when subjected to lengthy cook times, vitamins contained within the food items are subject to thermal degradation, and spices placed in contact with food items are washed from desired placement. Alternatively, foods cooked with other foods blend their flavors, which may not be desired. 
     To avoid some of these problems, steam is sometimes utilized. The usual methods of cooking with steam are through use of a double-boiler or a steamer insert of bamboo or metal. Disadvantages exist in both types of these steam-utilizing inserts. In the case of a metal double boiler, the high-heat capacity of water is under-utilized because the steam interacts with the inner vessel only and not with the food. In the case of a bamboo steamer, convective currents of a closed system are not utilized. 
     Moreover, in both cases, the vessel adjacent to the heat source is used exclusively as a water reservoir/steam generator. 
     A first attempt at the creation of a coincident multi-task cooking vessel capable for use as a full-service steamer, was made by Dzibinski in U.S. Pat. No. 5,511,466. The &#39;466 Patent discloses a wok-like cooking utensil which includes an integrated cooking trough about the upper perimeter of the cooking utensil. The &#39;466 Patent has certain drawbacks. First, when the lid is removed, for instance to stir-fry items in the bottom of the cooking utensil, the heat within the cooking trough is rapidly lost and not replaced while the lid is off. Second, even with the lid on, the design does not make use of the heat that could be generated from below the cooking trough. Third, the cooking utensil of the &#39;466 Patent is of unitary construction and does not allow for conversion to a conventional wok, nor does it allow for retrofitting of existing woks and pots. Fourth, the cooking trough will retain as liquid, any steam which has condensed on the lid thereby allowing the food items to sit in the condensation. 
     A removable cooking trough for use in a cooking vessel which would facilitate cooking several food items at the same time without co-mingling and while using the high-heat capacity of steam, would be an important improvement in the art. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to provide a cooking device that overcomes some of the shortcomings of the prior art. 
     Another object of the invention is to provide a cooking device that takes advantage of the constant temperature properties of steam to evenly cook food. 
     It is another object of the invention to take advantage of natural convection patterns within a covered wok to direct heat to an insert ring in a cooking device. 
     It is still another object of the invention to provide a cooking device that allows a person to cook two different food items in the same vessel without mixing the items within the vessel. 
     Another object of the invention is to cook food items within a vessel, exposing the food item to aromatic spicing sources without allowing physical contact between the food item and the spicing source. 
     It is yet another object of the invention to take advantage of pressurizing a cooking vessel to reduce the cooking time of food items. 
     Another object of the invention is to retrofit existing pots and woks with an insert that takes advantage of trough and covered-trough cooking. 
     Another object of the invention is to utilize steam for the cooking of items in one part of a vessel while allowing access with utensils to another part of the vessel where other items are being cooked at the same time. 
     How these and other objects are accomplished will become apparent from the following descriptions and from the drawings. 
     SUMMARY OF THE INVENTION 
     The invention involves an improved cooking system of the type having a cooking vessel with a watertight lower portion having a concave interior, and side walls extending generally upwardly from the bottom. The cooking vessel may have bottom which is flat, like a pot or rounded, like a traditional wok. The improvement is an annular, substantially hemi-toroidal insert. By “annular, . . . hemi-toroidal”, the applicant is describing a shape which resembles a tube wrapped into a donut shape and then cut horizontally to create a ring-shaped trough. By the use of the adverb “substantially”, the applicant is not limiting the cross-sectional shape to a semi-circle, but rather the trough can be of any cross-section, including the circle&#39;s antithesis, a square. The insert is dimensioned to engage the inner surface of the side walls or a lip near the top of the sidewall thereby removably supporting the insert within the cooking vessel remote from the bottom. The insert has a central opening (i.e., the “hole of the donut”) above the bottom of the cooking vessel, whereby the bottom of the cooking vessel may be accessed. In this way, utensils may be employed to manipulate the food cooking in the bottom of the pot or wok, ingredients may be added to the food cooking in the bottom of the pot or wok, liquid may be added to the bottom of the pot or wok, etc. 
     In one embodiment of the invention, the cooking trough includes a plurality of apertures which allow steam to contact the food items in the cooking trough from below and further allow liquid accumulating in the cooking trough to escape to the bottom of the cooking vessel. This embodiment is further improved by an annular, substantially hemi-toroidal, cover which substantially encloses the cooking trough. The insert cover is made more advantageous when the insert cover is segmented. In this way, one segment may be displaced to view or to test the contents of the insert without opening the whole trough. 
     In another embodiment, the cooking vessel has side walls which terminate in a upwardly-extending circular rim having an inside diameter. The cooking vessel further includes a hollow dome-like lid having inner and outer surfaces terminating in a radially extending outer rim and is removably supported by the cooking vessel sidewalls. In another aspect of this embodiment, the outside diameter of the lid is less than the inside diameter of the vessel rim such that the dome-like lid is removably supported by the cooking vessel sidewalls in a position entirely enclosing the insert. In yet another aspect of this invention, the lid is releasably sealed to the sidewalls; in this way, the benefits of increased pressure may be utilized, for instance to decrease cooking time. 
     In another preferred embodiment, the insert is a truncated annulus having an arcuate range of at least 180° about a main axis of the annular, substantially hemi-toroidal insert. In another aspect of this embodiment, end walls located at the truncated ends of the insert substantially enclose at least the lower portion of the cooking trough, thereby preventing items placed in the insert from falling out of the ends. In yet another aspect of this embodiment, there is a truncated annular, substantially hemi-toroidal insert cover to substantially enclose the truncated cooking trough. It is yet more advantageous in this aspect for the truncated insert cover to be segmented. 
     In another embodiment of the invention, the cooking vessel has bowl-like side walls such that it has horizontal, circular cross-sections. Each of the circular cross-sections has a common side-wall axis. The insert has a main axis which is coaxial with the side-wall axis. 
     In another embodiment of the invention, a substantially perforated partition is removably secured with respect to the insert across the central opening thereof. It is desirable for the partition to be a horizontal, screen cooking surface. It is another desirable embodiment for the partition to be an upwardly opening, downwardly extending, concave mesh basket. 
     It is another aspect of this invention to provide a insert for vertical insertion into a cooking vessel having a bottom and side walls extending upwardly therefrom. The cooking vessel side walls have an upper portion having an interior surface of a specific shape. The insert has an annular trough member extending circumjacent along the inner surface of the side walls. The trough member has a generally convex lower surface with a sidewall-adjacent portion of the lower surface complementary in shape to the inner surface of the sidewalls. The trough member has an upwardly-opening, concave upper surface. There is also at least one support member secured with respect to the trough member and in engageable contact with the side walls whereby the trough member is removably supported within the cooking vessel by the side walls. 
     In a preferred embodiment, the insert includes at least one support member engageable with the interior of the cooking vessel such that the trough member is removably supported with respect to the cooking vessel in a position remote from the bottom of the cooking vessel. In a more preferred embodiment, the insert includes at least three support members, each support member attached with respect to the convex lower surface of the trough member and each support member engageable with the interior of the cooking vessel such that the trough member is removably supported with respect to the cooking vessel in a position remote from the bottom of the cooking vessel. 
     In yet another embodiment of the invention, the trough member is composed of spun aluminum. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate preferred embodiments which include the above-noted characteristics and features of the invention. The invention will be readily understood from the descriptions and drawings. In the drawings: 
     FIG. 1 is a partially-exploded perspective view of an insert according to this invention. 
     FIG. 2 is a top view of the invention installed within a cooking vessel. 
     FIG. 3 is a vertical cross-section of the insert and cooking vessel of FIG. 2 taken along the line  3 — 3 . 
     FIG. 4 is a cross-section of the invention additionally containing the cooking vessel lid and the insert cover. 
     FIG. 5 is a top view of the cooking system showing an annular insert with a segmented insert cover and showing one of the segmented insert covers removed. 
     FIG. 6 is a cross-sectional view of yet another embodiment of the invention showing a flat-bottom insert member. 
     FIG. 7 is an exploded perspective view of an embodiment of this invention. 
     FIG. 8 is a partial cross-sectional view of the insert and insert cover, with screen-support members. 
     FIG. 9 is a top view of the cooking system showing an annular insert in which the insert does not extend along the entire perimeter of the cooking vessel and includes segmented insert covers with one of such covers removed. 
     FIG. 10 is a perspective view of the truncated insert device of FIG.  9 . 
     FIG. 11 is a cross-sectional view of an alternate embodiment of the invention in a cylindrical cooking vessel. 
     FIG. 12 is an enlarged cutout of the cross-sectional view of FIG. 11 taken along the cut-line  12 . 
     FIG. 13 is a cross-sectional view of an alternate embodiment of the invention with insert-support members in a substantially cylindrical cooking vessel. 
     FIG. 14 is a cross-sectional view of an alternate embodiment of the invention with insert-support members in a substantially bowl-shaped cooking vessel. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     As can be seen in FIG. 1, a cooking system in accordance with the present invention is generally designated by the reference numeral  10 . Cooking system  10  includes an insert  12  for placement in a cooking vessel  14 . As depicted, cooking vessel  14  is a wok. As will be seen later, the invention is not limited to use in a wok. Cooking vessel  14  has a bottom  16  integral with side walls  18  which extend up to create a water-tight vessel. Bottom  16  may be convexly rounded as depicted in FIG. 1 or flat as depicted in FIGS. 3,  4 ,  6 , and  11  without appreciable difference in the operation of the system. Similarly, side walls  18  may be curved as shown in FIGS. 1-4 or substantially vertical as shown in FIG.  11 . As seen in FIGS. 2,  5 , and  9 , the circumference of cooking vessel  14  is typically circular, but the invention is not limited to the shape of the upper rim  19  of cooking vessel  14 . 
     It is necessary that cooking vessel  14  be made of a material that is water-tight and either heat conductive or heat retentive. Coking vessel  14  is preferably of a metal and most preferably of spun aluminum chosen for its low weight, low cost, and heat-transmissive properties. Other suitable materials given by way of illustration and not by limitation include pressed or stamped stainless steel, rolled carbon steel, or copper. The invention is also adaptable to ceramic cooking vessels. 
     Cooking vessel  14  includes handles  20  which are typically attached by welds or rivets to the exterior surface  22  of cooking vessel  14 . The presence of handles  20  allow for manual stabilizing of cooking vessel  14  while in the cooking process and also facilitates the transportation of cooking vessel  14 . Handles  20  are most preferably of a non-heat conducting material such as wood or heat-resistant plastic to allow for manipulation while in operation; handles  20  can be metal for ease of construction and durability. A lid  24  is provided for cooking vessel  14 . 
     Lid  24  for a wok-type cooking vessel is preferably of a hemispherical shape with a vertical terminus  25 , and is most typically of spun aluminum. At the apex of lid  24  is a lid grip  26 . Lid grip  26  is most preferably a wooden knob or handle attached to lid  24  by a fastener  28  driven up through lid  24  to engage lid grip  26 . Lid  24  has a weight which tends to pressurize the interior of cooking vessel  14 . 
     As can be seen in FIGS. 2 and 3, insert  12  has a concave upper surface  30  to create a trough  34  and convex lower surface  32 . As shown in FIG. 3, trough  34  has uniform curvature. While aesthetically pleasing, it should be realized that regular curvature is not necessary for the proper functioning of the invention. The cross-section may be of any geometric shape including, for example only, a flat bottom as depicted in FIG.  6 . 
     It is preferable that trough  34  be made of a heat-conducting and heat-retaining material. For reasons stated above, spun aluminum is a preferred material for the construction of insert  12 . Trough  34  has a series of apertures  36  spaced evenly throughout. These apertures  36  provide two functions: to allow for steam  44  to penetrate trough  34  from underneath and to allow for any fluid found in trough  34  dueto juicing of food items  38  or condensation of steam  44 , to flow back down into bottom  16  of cooking vessel  14 . Trough  34  is of sufficient depth to receive food items  38  within. By food items  38 , applicant is not only referring to consumable items such as vegetables and meat, but aromatic spices and seasonings such as garlic or onions which may not be cooked for intention of direct consumption but rather placed in trough  34  to season other food items  38  placed in bottom  16  of cooking vessel  14 . 
     Trough  34  is most advantageously approximately three inches in depth and four inches in width at the uppermost edges thereof. As shown in FIGS. 2 and 3, insert  12  is an annular ring running the full 360° circumjacent to the inner edge  40  of cooking vessel  14  remote from bottom  16 . 
     A portion of lower surface  32  of trough  34  snugly engages inner edge  40  of sidewall  18  of cooking vessel  14  and thus is supported by sidewalls  18  of cooking vessel  14  in its location remote to bottom  16  of cooking vessel  14 . As seen in FIGS. 2 and 5, trough  34  runs 360° around edge  40  of cooking vessel  14 , which in this embodiment is a round cooking vessel. It should be noted, however, that the proper function of the device is not dependent on the range through which trough  34  extends around the circumference of cooking vessel  14 . In order to be supported by sidewalls  18  of cooking vessel  14  without slippage, trough  34  must cover at least 180° of the circumference of a circular cooking vessel  14 . 
     Turning to FIGS. 4 and 7, cooking system  10  is most advantageously presented when trough  34  has a insert cover  42  extending around trough  34 . Insert cover  42  is of a similar material as trough  34 . Insert cover  42  accomplishes either of two purposes: to retain heat within trough  34 ; and to protect food items  38  within trough  34  from contact with steam  44  generated within cooking system  10  when utilized with lid  24 . 
     Turning to FIGS. 4 and 5, insert cover  42  is made more advantageous by the inclusion of heat-insulating trough handles  46  strategically placed on insert cover  42  to allow for easy removal of insert cover  42  from insert  12 . Insert cover  42  is made even more advantageous by segmenting it. As depicted in FIG. 5, the annular ring insert cover  42  has been divided into three segments. In this way, during the cooking process, one segment of insert cover  42  may be removed to allow for inspection of food items  38  within trough  34  without releasing heat from the entire trough  34  and without subjecting all food items  38  within trough  34  to steam  44 . Being segmented, insert cover  42  will be easier to handle by the cook as well. 
     Insert cover  42 , to accomplish either of its dual purposes, need not have the same depth as trough  34 . It has been shown that for a trough  34  of a three-inch depth, a cover of one and one-half inches depth is sufficient for most purposes. Insert cover  42  most typically does not bear apertures. 
     As seen is FIG. 7, heat from a heat source  48  is applied to bottom  16  of cooking vessel  14 . The heat is conducted to the liquid  50  in bottom  16  of the cooking vessel  14 . As the heated liquid  50  becomes steam  44 , it rises as shown by arrows  52   a . As steam  44  reaches the upper portions of cooking system  10 , it encounters the apex of lid  24  and is deflected downward along lid  24  toward insert cover  42  shown by arrows  52   b . Steam  44  then flows around the exterior of insert cover  42  and trough  34  having transferred some of its radiant heat to trough  34  and insert cover  42 . The slightly cooled steam  44  then descends back toward liquid  50  where it is re-energized and returns to steam path  52   a . At the same time, liquid  52  heated at the periphery of cooled liquid  50  is heated and rises to encounter lower surface  32  of trough  34  thereby transferring some of the heat of steam  44  to said lower surface  32 . As shown by arrows  54   a  said cooled steam  44  is re-energized and takes a convective path. 
     At the same time that heat is being conducted to liquid  50  from heat source  48 , some of the heat is conducted along sidewalls  18  of metallic pan  14  to encounter lower surface  32  of trough  34  at an interface  56  between lower surface  32  of trough  34  and sidewalls  18  of cooking vessel  14 . In this way, food items  38  contained within trough  34  receive heat from all directions thereby preventing hot spots and promoting efficient cooking. 
     Also demonstrated in FIGS. 5 and 9 is the attribute of a central opening  60  through which utensils  62  may extend to reach bottom  16  of cooking vessel  14 . In this way, food items  38  may be stir-fried or sauteed in bottom  16  of cooking vessel  14  while coincidentally other food items  38  may be warmed in trough  34 . Further, fluid or ingredients may be added to bottom  16  of cooking vessel  12  without disrupting the contents of trough  34 . 
     When bottom  16  of cooking vessel  14  contains liquid  50  for steam generation as shown in FIG. 6, a horizontal screen  64  (FIGS. 7,  8 ) may be advantageously placed over a portion of central opening  60 . Preferably, screen  64  is removably supported by a screen-support member  66  extending radially inwardly from lower surface  32  of trough  34 , thereby holding screen  64  in a stable, horizontal position. Screen  64  is composed of a metal mesh or grid which allows ascendent steam  44 , as seen in FIG. 6, to encounter food items  38  placed on screen  64 . In this manner, different food items  38  may be steamed on screen  64  and in trough  34  at the same time without their juices being in contact. 
     FIGS. 9 and 10 illustrate another embodiment of cooking system  10  wherein insert  12  is a truncated annulus. As described above, within a circular cooking vessel  14  as depicted, annular insert  12  has an arcuate range of at least 180° and is thus able to be supported by sidewalls  18  within cooking vessel  14 . End walls  68  are provided to substantially enclose at least the lower portion of the truncated ends of trough  34  to prevent food items  38  from rolling or falling out of trough  34 . As shown, segmented insert covers  42  are provided of a complementary shape to cover trough  34 . With a truncated annular insert  12 , it is easier for a cook manipulating food  38  within cooking vessel  14  with a utensil  62 . As shown, while food items  38  are being cooked in bottom  16  of cooking vessel  14 , segmented insert cover  42  may be removed and food items  38  within trough  34  may be checked. 
     Insert  12  is most preferably supported by side wall  18  of cooking vessel  14  through engagement at interface  56  with lower surface  32  of trough  34 . In the alternative, another embodiment as shown in FIG. 11 is provided. In this embodiment, a cylindrical or square cooking vessel  14  with near vertical side walls  18  is depicted. As best seen in FIG. 12, sidewall  18  terminates at an upper rim  19  having a radially outwardly extending ledge  70 . Insert  12  includes a radially outwardly extending brim  72 . Ledge  70  removably and supportingly receives brim  72  of insert  12 . Alternatively, support members  74  (FIGS. 13,  14 ) may be provided to extend between insert  12  and the interior of cooking vessel  14 . Support members  74  may be of any configuration (including for example, inclined, vertical or horizontal) which allow insert  12  to be supported within cooking vessel  14  remote from bottom  16  thereof. Support members  74  may be integral with either insert  12  or cooking vessel  14 , or may be removable with respect to both. Alternative configurations of support members  74  allow for retrofitting existing cooking vessels  14  and further create new convection patterns. 
     While the principles of the invention have been shown and described in connection with but a few embodiments, it is to be understood clearly that such embodiments are by way of example and are not limiting.

Technology Classification (CPC): 0