Abstract:
A multifunctional griddle having hinged top and bottom heating plate assemblies which receive reversible cooking plates or, alternatively, interchangeable cooking plates for cooking different types of foods such as waffles, pancakes, and hot sandwiches. In one embodiment the reversible cooking plates are nested in face-to-face contact with mating top and bottom heating plates to improve heat transfer to the cooking plates. This is accomplished by forming a mating waffle grid in the heating plates for receiving the waffle iron surfaces of the cooking plates in intermeshing engagement. The intermeshing engagement of the cooking plates with the heating plates also reduces the overall vertical height of the appliance providing a slimmer profile. In an alternative embodiment a set of interchangeable cooking plates is provided having a sliding interface with modified heating plates. In this embodiment the cooking plates are conveniently interchanged to vary the cooking configurations of the appliance.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This is a divisional patent application of a parent application, namely, U.S. patent application Ser. No. 10/934,882 filed Sep. 7, 2004, now U.S. Pat. No. 7,064,298, which is entitled Multifunctional Griddle, and claims the benefit thereof under 35 U.S.C. 120. 

   BACKGROUND OF INVENTION 
   The present invention relates to home cooking appliances such as waffle irons and portable grills and, more particularly, to a multifunctional griddle for cooking different types of food products by means of reversible or, in the alternative, interchangeable cooking surfaces. 
   A variety of cooking appliances which permit cooking of different food products by the use of reversible cooking elements are known in the prior art. For example, U.S. Pat. No. 2,899,888 to Koci discloses one such cooking appliance in the form of a combined waffle baker and grill. This particular appliance has two hinged cases. Each case contains a radiant heating element to one side of a cooking grid. Each grid has a flat cooking surface on one side and a waffle cooking surface on the opposite side. To change from one surface to another, each grid is reversed and reinserted into its corresponding case. It has been found that cooking appliances, such as shown in the Koci patent, that use radiant heating of one side of the grid produce uneven heating of the grid and inefficient heat transfer that leads to longer baking times. Temperature control of a baking surface as shown in the Koci patent is obtained by sensing the temperature of separate thermal masses that possess characteristics similar to the cooking grid. This approach does not always provide accurate temperature control of the heating elements. Reversing the grids requires the grids to be removed. This procedure exposes the heating elements, which are subject to damage if contacted. Further, this feature makes it difficult to clean the interior of such cooking appliances. 
   U.S. Pat. No. 3,998,145 to Maisch discloses a combination grilling and baking apparatus with two hinged parts. Each part carries a cooking element that has different cooking surfaces. The Maisch patent discloses waffle baking and meat grilling surfaces. Each cooking element has a central elongated and transverse sleeve. Each hinge part carries a heating element. When a cooking element is installed the heating element inserts into the sleeve. This apparatus seems to use a conventional bi-metal control for temperature. Like the device shown in the Koci patent, the combination grilling and baking apparatus disclosed in the Maisch patent requires direct handling of the cooking elements and exposure of the heating element when a cooking element is removed for reversal. Further, even with the cooking elements removed, the heating element makes it difficult to clean the remainder of the cooking appliance. 
   Other examples of electric cooking appliances having reversible cooking surfaces are disclosed in U.S. Pat. No. 6,555,795 to Glucksman et al. and U.S. Pat. No. 3,348,470 to Swanson. 
   While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose the features of the present multifunctional griddle. 
   SUMMARY OF THE INVENTION 
   The present multifunctional griddle is a cooking appliance having top and bottom heating plates which receive reversible cooking plates or, alternatively, interchangeable cooking plates for cooking different types of foods such as waffles, pancakes, hot sandwiches, and other food items. The cooking plates are constructed of highly heat conductive materials, which are nested in intermeshing engagement with top and bottom heating plates to provide more efficient heat transfer to the cooking surfaces. The intermeshing engagement of the cooking plates also reduces the vertical dimension between the hinged heating plates providing a slimmer profile for the present appliance. 
   There has thus been outlined, rather broadly, the important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
   Other features and technical advantages of the present invention will become apparent from a study of the following description and the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The novel features of the present invention are set forth in the appended claims. 
     The invention itself, however, as well as other features and advantages thereof will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying figures, wherein: 
       FIG. 1  is a perspective view of one embodiment of the multifunctional griddle of the present invention; 
       FIG. 2  is a top plan view of the multifunctional griddle of  FIG. 1  showing the orientation of section planes A-A and B-B; 
       FIG. 3  is a side elevation view of the multifunctional griddle of  FIG. 1  in a closed condition; 
       FIG. 4  is a side elevation view of the multifunctional griddle of  FIG. 3  in an open condition showing the reversible cooking plates; 
       FIG. 5  is a cross-sectional view of the reversible cooking plate of the present embodiment taken along the section plane A-A of  FIG. 2 ; 
       FIG. 6  is a perspective view of the multifunctional griddle of  FIG. 1  in a waffle-maker configuration; 
       FIG. 7  is a perspective view of the multifunctional griddle of  FIG. 1  in a grilling configuration; 
       FIG. 8  is a cross-sectional view of the multifunctional griddle taken along section line A-A of  FIG. 2  showing the present griddle in the grilling configuration; 
       FIG. 9  is a cross-sectional view taken along section line B-B of  FIG. 2  showing the present griddle in the grilling configuration; 
       FIG. 10  is a cross-sectional view taken along section line A-A of  FIG. 2  showing the present griddle in the waffle-maker configuration; 
       FIG. 11  is a cross-sectional taken along section line B-B of  FIG. 2  showing the present griddle in the waffle-maker configuration; 
       FIG. 12  is an electrical schematic showing the components and circuitry of the present griddle; 
       FIG. 13  is a perspective view of another embodiment of the multifunctional griddle of the present invention; 
       FIG. 14  is a top plan view of the present griddle of  FIG. 13  showing the orientation of section planes A-A and B-B; 
       FIG. 15  is a side elevation view of the present griddle of  FIG. 13  in a closed condition; 
       FIG. 16  is a perspective view of the present griddle of  FIG. 13  in a waffle-maker configuration; 
       FIG. 17  is a perspective view of the present griddle of  FIG. 13  in a grilling configuration; 
       FIG. 18  is a cross-sectional view of the multifunctional griddle taken along section line A-A of  FIG. 14  showing the present griddle in a waffle-maker configuration; 
       FIG. 19  is a cross-sectional view taken along section line B-B of  FIG. 14  showing the present griddle in a waffle-maker configuration; 
       FIG. 20  is a cross-sectional view of the multifunctional griddle taken along section line A-A of  FIG. 14  showing the present griddle in a grilling configuration; 
       FIG. 21  is a cross-sectional view taken along section line B-B of  FIG. 14  showing the present griddle in a grilling configuration; and 
       FIG. 22  is an electrical schematic showing the components and circuitry of the present griddle. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   With further reference to the drawings there is shown therein a multifunctional griddle in accordance with the present invention, indicated generally at  10  and illustrated in  FIG. 1 . The present multifunctional griddle  10  includes an upper housing section  20  and a lower housing section  30 . The upper housing section  20  and the lower housing section  30  are provided with interconnecting means, including but not limited to, the following structures. In the embodiment shown the upper housing section  20  and the lower housing section  30  are interconnected by a pivoting hinge mechanism, indicated generally at  50  as more clearly shown in  FIGS. 2 and 3 . Housing frame members  16 ,  17  extend about the periphery of upper and lower housing sections  20 ,  30  respectively and function to retain the cooking plates  25  ( FIG. 4 ). 
   The upper housing section  20  includes a cover  37  that provides access to a temperature controlling means including, but not limited to, the following structures. In the present embodiment a rheostatic temperature controller  35  ( FIG. 8 ) is provided, which is actuated by a sliding control lever  26  as shown in  FIG. 1 . Alternatively, a completely electronic temperature controller (not shown) may be utilized for the present griddle  10 . Since such temperature control devices are well known to those skilled in the art, further detailed discussion of the same is not deemed necessary. 
   The upper and lower housing sections  20 ,  30  include upper and lower handles  22  and  32  respectively and are secured in the closed condition shown by latch mechanism  70  ( FIG. 1 ). Detachable feet  28  are also provided to support the present griddle  10  on a countertop or other working surface. 
   In the preferred embodiment housing sections  20 ,  30  are constructed of sheet steel, engineered composites, or other heat resistant materials and are provided in different exterior finishes such as heat-resistant paint, powder coating, stainless steel, or plated steel. 
   In  FIG. 4  it can be seen that the multifunctional griddle  10  includes two cooking plates  25  which may be withdrawn from the housing sections  20 ,  30  by the user (as shown by directional arrows  60 ) to reverse the cooking surfaces depending on the cooking mode to be utilized. 
   In the embodiment seen in  FIG. 5 , the cooking plates  25 ,  35  are provided with a waffle iron surface, indicated generally at  40 , on a first side thereof and a grilling surface, indicated generally at  55 , on a second side, which enables the present griddle  10  to function in the cooking configurations shown in  FIGS. 6 and 7  respectively. In the preferred embodiment cooking plates  25  are constructed from cast aluminum, cast iron, steel, or other suitable material having a high coefficient of heat conductivity. 
   With reference to  FIGS. 8 and 9 , the upper and lower housing sections  20 ,  30  enclose upper and lower heater assemblies, indicated generally at  23  and  33  respectively. Each heater assembly  23 ,  33  is comprised of a heating plate  21 ,  31  and a tubular heating element  24 ,  34  disposed within each heating plate. Heating plates  21 ,  31  are also constructed from a highly heat conductive material such as cast aluminum, cast iron, steel or other suitable material. In the embodiment shown in  FIGS. 8 and 9 , heating elements  24 ,  34  are constructed of stainless steel tubing or other suitable tubing wherein a resistance heater wire  45  is enclosed. 
   Advantageously, the heating plates  21 ,  31  are configured to provide a complementary, mating surface for intermeshing engagement with the waffle iron surface  40  of the cooking plates  25  to improve heat transfer therebetween as illustrated in  FIGS. 8 and 9 . More particularly, it can be seen that the waffle iron surface  40  of each cooking plate  25  is divided into quadrants or waffle grids, indicated generally at  50 , by perpendicular cross-bars  52  ( FIG. 6 ), which extend transversely across the cooking plates. Waffle grids  50  are comprised of a plurality of trapezoid-shaped protuberances  38  arranged in parallel rows and columns in a grid pattern. 
   Similarly, the inwardly facing, opposed surfaces of heating plates  21 ,  31  shown in  FIGS. 8 and 9  are divided into matching quadrants separated by perpendicular grooves  54 . The surfaces of heating plates  21 ,  31  are comprised of similar trapezoid-shaped depressions  39  arranged in parallel rows and columns in a mating grid pattern. When the present invention is configured for use as a grill ( FIG. 7 ), the waffle iron surface  40  of each cooking plate  25  (depicted in hidden lines  FIGS. 8 and 9 ) is nested into its mating heating plate  21 ,  31 . In this configuration the mating protuberances  38  of each cooking plate  25  are disposed in intermeshing engagement with the depressions  39  of each heating plate  21 ,  31  providing direct contact therebetween for improved heat transfer to the cooking plates  25 . 
   When the cooking plates  25  are reversed in configuration as shown in  FIGS. 10 and 11  such that the present griddle  10  functions as a waffle-maker ( FIG. 6 ), the grilling surface  55  of each cooking plate  25  is disposed in face-to-face relation in contact with its corresponding heating plate  21 ,  31  providing for maximum heat transfer to the cooking plates. 
   Referring to  FIG. 12  there is shown an electrical schematic of the present griddle  10  illustrating the components and circuitry thereof. In the embodiment shown the top and bottom heating elements  24 ,  34  are arranged in parallel electrical circuits interconnected with the temperature controller  35  and a standard 110 volt power source  75  for residential use. The circuitry also includes a Power-ON indicator light  62  and a Work indicator light  65  showing that the heating elements  24 ,  34  are activated. 
   Referring now to  FIG. 13  there is shown another embodiment of the present multifunctional griddle, indicated generally at  10 ′. In this embodiment the griddle  10 ′ includes an upper housing section  20 ′ and a lower housing section  30 ′, which are interconnected by a modified hinge assembly, indicated generally at  50 ′, as more clearly shown in  FIGS. 14 and 15 . 
   In this embodiment the housing frame members  16 ,  17  of the previous griddle  10  ( FIG. 1 ) are omitted based on structural modifications disclosed hereinafter in further detail. The upper housing section  20 ′ includes a cover  37 ′ that provides access to a temperature controlling means including, but not limited to, the following structures. In the present embodiment a rheostatic temperature controller  35  ( FIG. 13 ) is provided, which is actuated by a sliding control lever  26 . Alternatively, an electronic temperature controller (not shown) may be utilized to operate the present griddle  10 ′. 
   The upper and lower housing sections  20 ′,  30 ′ include the same upper and lower handles  22 ,  32  respectively and are secured in the closed condition shown by latch mechanism  70  ( FIG. 13 ). Detachable feet  28  are also provided to support the present griddle  10 ′ on a countertop or other working surface. 
   In the preferred embodiment housing sections  20 ′,  30 ′ are also constructed of sheet steel, engineered composites, or other heat resistant materials and are provided in different exterior finishes such as heat-resistant paint, powder coating, stainless steel, or plated steel. 
   In  FIGS. 16 and 17  it can be seen that griddle  10 ′ includes a plurality of interchangeable cooking plates  25 ′ and  25 ″ respectively, which may be slidingly withdrawn from the housing sections  20 ′,  30 ′ by the user (as shown by directional arrows  60 ) providing different cooking surfaces depending on the cooking mode to be utilized. 
   Cooking plates  25 ′,  25 ″ are provided with plate retaining means including, but not limited to, the following structures. In the embodiment shown each cooking plate  25 ′,  25 ″ is provided with an integral clasp  27  formed on the forward edge thereof, which interlocks with a retaining clip  29  positioned adjacent each handle  22 ,  32  to secure the cooking plates  25 ′,  25 ″ in position during operation. In addition, a retaining ledge  58  ( FIG. 18 ) is formed on the back edge of each heating plate  21 ′,  31 ′ that engages cooking plate retainers  59 , which are integrally formed on the opposed half-sections  50   a ′,  50   b ′ of hinge  50 ′. 
   In the embodiment shown in  FIG. 16 , the cooking plates  25 ′ are provided with a waffle iron surface, indicated generally at  40 , on a first side thereof and a flat heat transfer surface, indicated generally at  57 ′, on the opposite side. In the embodiment shown in  FIG. 17 , the cooking plates  25 ″ are provided with a grilling surface, indicated generally at  55 ′, on a first side thereof and a flat heat transfer surface, indicated generally at  57 ′, on the opposite side. The interchangeable cooking plates  25 ′,  25 ″ enable the present griddle  10 ′ to function in the cooking configurations shown in  FIGS. 16 and 17  respectively. Cooking plates  25 ′,  25 ″ are constructed from cast aluminum, cast iron, steel, or other suitable material having a high coefficient of heat conductivity. 
   With reference to  FIGS. 18-21 , the internal structure of the present griddle  10 ′ is shown in further detail. The upper and lower housing sections  20 ′,  30 ′ enclose upper and lower heater assemblies, indicated generally at  23 ′ and  33 ′ respectively. Each heater assembly  23 ′,  33 ′ is comprised of a heating plate  21 ′,  31 ′ and an integrated heating element  24 ,  34 . Heating plates  21 ,  31  are also constructed from a highly heat conductive material such as cast aluminum, cast iron, steel or other suitable material. Heating elements  24 ,  34  are constructed of stainless steel tubing or other suitable tubing wherein a resistance heater wire  45  is enclosed. 
   In the present griddle  10 ′ it can be seen that heating plates  21 ′,  31 ′ are configured such that the inwardly facing surfaces thereof are flattened to provide a sliding interface as shown by directional arrows  60  ( FIGS. 16 and 17 ) with the flat heat transfer surfaces  57 ′ of cooking plates  25 ′,  25 ″ for convenient interchangeability by the user. 
   In the embodiment shown in  FIGS. 18 and 19  the griddle  10 ′, cooking plate  25 ′ is installed to provide a waffle-maker configuration. In this arrangement the heat transfer surfaces  57 ′ of cooking plates  25 ′ are disposed in face-to-face contact with heating plates  21 ′,  31 ′ respectively providing for optimum heat exchange therebetween. When the cooking plates  25 ′ and  25 ″ are interchanged as shown in  FIGS. 20 and 21  such that the present griddle  10 ′ functions as a pancake grill or sandwich-maker, the heat transfer surfaces  57 ′ of each cooking plate  25 ″ are similarly disposed in face-to-face contact with heating plates  21 ′,  31 ′ providing for efficient heat transfer to the cooking plates. 
   Referring to  FIG. 22  there is shown an electrical schematic of the griddle  10 ′ illustrating the components and circuitry thereof. As in the previous embodiment (FIG.  12 ) the top and bottom heating elements  24 ,  34  are arranged in parallel electrical circuits interconnected with the temperature controller  35  and standard 110 volt power source  75  for residential use. In this embodiment the circuitry also includes a Power-ON indicator light  62  and a Work indicator light  65  showing that the heating elements  24 ,  34  are activated. 
   Although not specifically illustrated in the drawings, it should be understood that additional equipment and structural components will be provided as necessary and that all of the components described above are arranged and supported in an appropriate fashion to form a complete and operative multifunctional griddle incorporating features of the present invention. 
   Moreover, although illustrative embodiments of the invention have been described, a latitude of modification, change, and substitution is intended in the foregoing disclosure, and in certain instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of invention.