Patent Publication Number: US-2011056957-A1

Title: Combination Multiple Vessel Cookware

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to and the benefit of the US Provisional Patent application of the same title, filed on 4 Sep. 2009, having application Ser. No. 61/239,858, which is incorporated herein by reference. 
    
    
     BACKGROUND OF INVENTION 
     The present invention relates to a cookware article and in particular to combination cooking vessel for steaming food, and more particularly for cooking rice. 
     The cooking of rice in a pot directly exposed to an external heat source, such as a flame or electric heating element, can be problematic due to the difficulty of controlling the temperature throughout the cooking cycle. 
     It is easy for inexperienced cooks to either boil over the water, or burn the rice if the temperature is not carefully controlled or the pot not closely watched. Electric rice cookers have become popular for this reason. 
     However, for many consumers electric rice cookers consume too much counter space, or do not produce rice with the desired texture. Further, electric rice cookers have limited capacity to minimize cost. 
     It is therefore a general object of the present invention to provide an improved means for cooking rice consistently on a stove top, avoiding the foregoing deficiencies of the prior methods and equipment. 
     SUMMARY OF INVENTION 
     In the present invention, the first object is achieved by providing a article of cookware comprising an outer fluid retaining vessel having a bottom and substantially upright surrounding walls terminating at a first rim and having an inner diameter, an inner vessel fluid retaining vessel having a bottom and substantially upright surrounding walls terminating at a second rim, wherein the inner fluid retaining vessel is shorter than the outer fluid retaining vessel, and the diameter of the inner rim is narrower than the inner diameter of the outer vessel, a lid that sealingly engages at least one of the inner and outer fluid retaining vessel at the rim thereof, wherein the inner fluid retaining vessel further comprises at least one of a laterally extending flange and a plurality of laterally outward extending supports members for coupling to the outer fluid retaining vessel for nested suspension substantially therein on a rim coupled portion thereof, wherein the gap between the inner rim and the outer rim is partially open such that steam generated in the outer fluid retaining vessel can circulate into the volume of the inner fluid retaining vessel via the gap. 
     The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  is a cross-sectional elevation of a first embodiment of the vessel combination. 
         FIG. 1B  is a cross-sectional elevation of the portion of the vessel lid region of  FIG. 1A  in a larger view 
         FIG. 2  is a plan view of the vessel combination in  FIGS. 1A and 1B  with the lid removed. 
         FIG. 3A  is a cross-sectional elevation of an alternative embodiment of the vessel combination. 
         FIG. 3B  is a cross-sectional elevation of the portion of the vessel lid region of  FIG. 3A  in a larger view. 
         FIGS. 4A and 4B  are cross-sectional elevations of another alternative embodiment of the vessel combination. 
         FIG. 5  is a cross-sectional elevation of another alternative embodiment of the vessel combination. 
         FIG. 6  is a plan view of the embodiment of the vessel combination shown in  FIG. 5  with the lid removed. 
         FIG. 7  is a plan view of another alternative embodiment of the vessel combination with the lid removed. 
         FIG. 8  is a cross-sectional elevation of another alternative embodiment of the vessel combination. 
         FIG. 9  is a plan view of the vessel combination in  FIG. 8  with the lid removed. 
         FIG. 10  is a cross-sectional elevation of another alternative embodiment of the vessel combination. 
         FIG. 11  is a plan view of the vessel combination in  FIG. 10  with the lid removed. 
         FIG. 12  is a cross-sectional elevation of another alternative embodiment of the vessel combination. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 12 , wherein like reference numerals refer to like components in the various views, there is illustrated therein a new and improved Combination Multiple Vessel Cookware, generally denominated  100  herein. 
     In accordance with the present invention,  FIG. 1  illustrates an embodiment of the novel vessel combination  100 , which includes an outer vessel  110 , a lid  120  fitted to cover the outer vessel  110 , and an inner vessel  130  that is shorter and has at least a lower fluid containing portion narrower than the upper vessel to nest therein with a gap  105  between their lateral walls. At least one of the inner and outer vessels having a means to support the bottom of the inner vessel upward above the bottom of the outer vessel. It is generally preferred that such a support means is integral with at least one of the inner and outer vessel. More preferably, the inner vessel  130  is suspended from the rim  111  of the outer vessel  110  to provide the gap  105  for steam or water vapors  3  generated by boiling water  1  in the lower portion of the outer vessel  110 , that is below the inner vessel  130 , so that these vapors diffuse to reach the contents of the inner vessel  130 . Lid  120  has an upper handle  125  for removal from at least one of the inner and outer vessel, as is discussed further below. 
     One means of providing the gap  105  between the inner and outer vessel is for the inner fluid containing vessel  130  to have an outward extending flange  132  at the rim  131 . The flange  132  is perforated with a plurality of holes  133  to allow steam  3  to enter the head space below the lid  120 , and hence penetrate to the contents  2  of the inner vessel  130 . In this embodiment, the flange  132  extends to a sufficient external diameter to rest on the rim  111  of the outer vessel  110 . Thus, it should be appreciated that in this embodiment to retain steam  3 , the lid  120  has a lower extending rim  121  dimensioned to sealingly engage the outer vessel  110  at a portion of the rim  111  to extend over and also cover the entire inner vessel  130 , including the flange  132 . More details of the engagement of the vessels and lid at their respective rims are shown in  FIG. 1B . Rim  111  has an outer peripheral and laterally extending flange portion  112  followed by an upward wall  113  to fully seat the lower rim  121  of the lid  120 . 
     Thus, water  1  boiled or simmering in the bottom of the outer vessel  110  produces steam  3  which can enter gap  105 , and flowing through holes  133  in flange  132 , can penetrate rice  2  or other foodstuff, such as other grains, vegetables, dumplings and the like in inner vessel  130 . 
     For cooking rice, water and rice grains are placed in the inner vessel  130 , with water placed in the outer vessel  110 . As the inner vessel  130  is heated by the water boiling in the outer vessel, the water or contents of the inner vessel is never overheated to a rolling boiling and hence does not foam up and spill or leak at the converge of the rim  131  with the lid  120 . Further, as the rice completes cooking it can never dry out and burn even when the water placed in the inner vessel  130  is totally absorbed by the rice, as it receives steam or water vapor generated in the lower vessel. Even in the case of the unlikely consumption of all the water in the outer vessel  110 , the inner vessel  130  contents will not reach the temperature of the external heat source. 
     Further, the thermal mass of the water in the outer vessel  110  after cooking, as well as the abundant moisture surrounding the cooked rice in the inner vessel  130  will keep it both warm and moist for a long period of time. It is expected that other grains can be cooked in a similar manner with comparable benefits, as well as steaming food in the inner vessel  130  with adding water. 
     Hence, the vessel combination  100  is extremely versatile, being suitable for use as a rice cooker, steamer and double-boiler. It use provide cooks with a means to consistently cook rice to pleasing texture and flavor, avoiding over stickiness of the grains. Use of the vessel combination as described above also avoids foaming and over-boiling of water than can occur when cooking rice on a gas or electric range. The vessel combination can be readily scaled to large sizes for institution use, as in smaller size for home cooking Depending on the vessel capacity, it can be left on low heat or simmer for an hour or two without burning or over cooking 
     It is preferred that the perforation in the inner vessel flange  132  are a series of holes  133  equally spaced along the circumference thereof, as shown in the plan view of the vessel in  FIGS. 1A and 1B  in  FIG. 2 . Alternative means of providing vapor communication between the head space above the outer vessel  110  and the interior of the inner vessel  130  are illustrated in other figures for different embodiments, as described below, and may include differently shaped perforation. 
     In general, to support the inner vessel  130  inside the outer vessel  110 , it is currently preferred that the rim of the outer fluid retaining vessel  110  comprises an outward extending portion  112  followed by an upward extending portion  113  that terminates at the rim&#39;s outer periphery  114 . 
       FIGS. 3A and 3B  illustrate a more preferred embodiment where the inner vessel is easily removed after cooking is complete. As can be seen in  FIG. 3B , the lower rim  121  of the lid  120  now engages the outward extending flange portion of the inner vessel  130 . 
     The inner vessel  130 , as shown in  FIG. 3   b , has two flanges like portions, the first  132  extending substantially laterally from the periphery of the vessel wall that defines an inner rim. The first or inner flange  132  rests on or otherwise engages the rim  111  of the exterior vessel  110 . A second outer flange  135  is also extends away substantially laterally, but connected to the inner flange  132  by a vertical wall  134 . Thus, this second flange  135  extends above and beyond the outer extremity  114  of rim  111  of the outer vessel  110 . The lid  120  now has a lower rim  121  that fits on the flange  132  just inside of wall  134 . It should now be appreciated that the portion of the flange  132  just outside of the holes  133  seals to the mating portion  122  of the rim of the outer vessel  110 . 
     After cooking, lid  120  is removed by handle  125 , then, if desired for serving or thereafter for cleaning, the inner vessel can be removed by grasping the outer flange  135 . 
     Most preferably, as shown in  FIG. 3B , the mating lid and rims of can have a slight concave profile at the lower surface to trap a thin film of condensed water. This thin film of water will then provides a vapor seal at low internal pressures, hence fully utilizing the steam  3  generated during cooking This cooperative contour of the lid with the rim of the inner and outer vessel is commonly known as a waterless seal because so little steam escapes from the vessel before the seal is formed that the nature water content of foodstuff is sufficient to avoid adding extra water to the food. However, in the preferred method of using the inventive cookware, this “waterless” seal generally avoids excessive evaporation during cooking 
     As the inner vessel  110  can have a thinner exterior wall that the exterior vessel  120 , which is subjected directly to a heating source. Thus, the end of the wall is preferably folded over as shown in  FIG. 3B , to form a thicker outer flange  135  that extends far enough away from the heat source and the outer vessel  110  to remain relatively cool. However, an external handle can also be attached to flange  135  to provide greater convenience, if it is desired to serve directly from the inner vessel  130 . 
     A similarly improved way of the removing the interior vessel  130  is provided by the embodiments shown in  FIG. 4A , as well as  FIGS. 5A and 5B .  FIG. 4A  shows an alternative combination vessel  100  as a partially cut-way cross section with the inner vessel  130  in place, and sealed by lid  120 .  FIG. 4B  shows the other half of the outer vessel  110  with the inner vessel  130  removed, but also sealed by lid  120 . In this embodiment the external portion  115  of the rim of the outer vessel  110  is tilted away from the vessel walls to conform generally to the complementary tilted profile of the outer vessel rim  111 . The inner vessel  130  rather than having a substantially laterally extending flange  132 , now has a complimentary tilted or conical flange  132 ′ (which a laterally outward extending component) with a plurality of spaced apart holes  133  in the lower portion. Above holes  133  the conical flange extends upward to an upper solid portion  136  that is preferably coated with silicone rubber  139  where it contacts the rim  111  of the outer vessel  110 . This extreme external portion of tiled flange  132  has an external thermally insulating grip  137 , such as a soft rubber but more preferably a silicone rubber grip along at least selected portion. Lid  120  is preferably transparent, more preferably also terminates at a rim  111  lined with a soft rubber or silicone rubber gasket. The external portion  115  of the rim of the outer vessel  110  and the inner and outer portion of the rim  136  of the inner vessel have the same shape or profile, in this instance conical, as the gasket at rim  111 , so that when the inner vessel  130  is removed, as in  FIG. 4B , the lid  120  sealingly engages the rim of the outer vessel  110 . 
     In the embodiment shown in  FIGS. 5 and 6  the inner vessel  130  has handles  501  extend inward for gripping and removal, after lid  120  is removed. 
     In the embodiment of  FIG. 7 , the flange  132  of the inner vessel  130  does not continue along the entire periphery, providing gaps  701  between portions of the flange  711  having a plurality of holes  133 . Thus, depending on the size of these gaps, the need for holes may be eliminated. Further, improvements to this embodiment include providing any of the handle or gripping means for the inner vessel  130 . 
     A shown in the embodiment of  FIGS. 8 and 9 , the outer fluid retaining vessel  110  can deploy an inward directing supporting means, such as an inner flange, shelf or posts  801  to support the inner fluid retaining vessel  130 . The inner retaining vessel  130  can have a complete flange  132  as shown in  FIG. 1-4 , the partial flange portion  711  shown in  FIG. 7 , or mating supports  801  that rest on a plurality of posts or stubs  801  that internally extend from the upper wall portion of the outer vessel  110 , and the like. 
     As also shown in the embodiment of  FIGS. 10 and 11 , the outer fluid retaining vessel  110  can have an integrated bottom heating element  1001 , with appropriate control for temperature regulation, as well as external insulation. 
     It should also be apparent that the lid  120  can have a pressure retaining engagement via an o-ring  1205  to the outer vessel  110  and a pressure release means, as shown in  FIG. 12 . In this embodiment, the outer vessel  110  and lid  120  are sealed by rotating the laterally extending handles pair  1210  and  1211  with respect to each other until they reach an engaged position that compresses the O-ring  1205 . The inner vessel  130  remains entirely within the outer vessel  110  and thus avoids inference with the sealing mechanism. The lid has multiple pressure release valves  1201  and  1202 . 
     In light of the teaching of the above specification, it should now be apparent to one of ordinary skill in the art that specific features of the various embodiments can be combined with or eliminated from certain embodiments to form a range of alternative devices that accomplish the same or comparable results. Thus, while the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.