Patent Publication Number: US-2010122977-A1

Title: Combined taoster and utensil knife heater

Description:
BACKGROUND OF THE INVENTION 
     Toaster has been a household appliance for toasting bread/bagel, etc. for long time. Very often, user may desire to spread butter/peanut butter, etc. over the toasted bread/bagel after toasting. It has always been a difficult experience for user to do so. This is because butter/peanut butter, which is normally required to be stored in a refrigerator, can be in a hardened state. 
     Author of present invention becomes aware that there is a simple solution to easy the task of spreading hardened butter/peanut butter over toasted bread/bagel. That is to preheat the spread knife. A spread knife with hot blade can easily and quickly cut through a chunk of butter/peanut butter. At the same time, hot blade can soften butter/peanut butter while spreading it over toasted bread. 
     The motivating factor of present invention is to utilize toaster as a heat source for heating the spread knife. The object of present invention is to convert a conventional toaster of prior art to a combined toaster and utensil knife heater unit. Such a combined unit offers the following advantages: 
     (1). It is cost effective. By utilizing the existing heating elements of toaster, there is no need to install additional heating elements for heating knife. The combined unit of present invention is essentially at the same manufacturing cost of conventional toaster. 
     (2). It reduces operational cost. The knife can be simultaneously heated up during toasting bread. There is essentially no energy cost for heating knife. 
     (3). It is user friendly. Upon completion of bread toasting cycle, heating of knife is also completed. User can then remove the toasted bread from toaster, while obtain the heated knife from toaster at the same time. 
     (4). It is commercially marketable. An independent knife heater in lieu of the combined unit of present invention costs consumer not only extra expenses, but also extra effort to operate. On the contrary, the above advantages (1), (2) and (3) offer the combined unit of present invention a cutting edge in competing with conventional toasters in toaster market. 
     SUMMARY OF THE INVENTION 
     One distinctive aspect of present invention is to allow bread and knife to be inserted through separate entries, and heated up in separate heating chambers without affecting operation and performance of toasting bread. 
     Another distinctive aspect of present invention is to allow bread and knife to be heated up simultaneously by the existing heating elements for toasting bread. 
     Another distinctive aspect of present invention is that only blade section of knife is heated up. Conduction heat transfer from blade section to handle section of knife is not sufficient to raise handle temperature to a degree uncomfortable for holding knife handle. 
     According to present invention, two side by side heating chambers are provided for toasting bread. Each heating chamber is provided between a pair of vertical planar heating elements to receive radiation heat and maximum heat capacity from heating elements. A separate heating chamber, which is capable of receiving heat dissipated from heating elements, is provided for heating knife(s). Knife is inserted into the heating chamber through a separate entry that is distant from the entries for inserting breads. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a typical toaster of prior art. 
         FIG. 2  is a perspective view of the first preferred embodiments of the combined toaster and utensil knife heater unit of present invention. 
         FIG. 3  is a cross sectional view of  FIG. 2 . 
         FIG. 4  is a perspective view of the second preferred embodiments of the combined toaster and utensil knife heater unit of present invention. 
         FIG. 5  is a cross sectional view of  FIG. 4 . 
         FIG. 6  is another cross sectional view of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF DRAWINGS 
       FIG. 1  is a perspective view of a typical toaster of prior art.  FIG. 2  is a perspective view of the first preferred embodiments of the combined toaster and utensil knife heater unit of present invention.  FIG. 3  is a cross sectional view of  FIG. 2 . 
     The object of present invention is to convert a toaster of prior art to a combined toaster and knife heater unit. Many features of the first preferred embodiments of present invention shown in  FIG. 2  and  FIG. 3  are identical to those of prior art. It is understood that various toasters of prior art may contain various features not shown in  FIG. 2  and  FIG.3 .  FIG. 2  and  FIG. 3  are not intended to show all various features of prior art, or to limit the features of first preferred embodiments of present invention to only those shown in  FIG. 2  and  FIG. 3 . Other features can be adopted in first preferred embodiments without exceeding the scope of present invention. 
     Features of the combined unit  1  of first preferred embodiments of present invention shown in  FIG. 2  and  FIG. 3 , which are identical to those of prior art, are described as follows. The combined unit  1  has an outer protective housing  2 , an inner metallic housing  3 , a left, center and right vertical planar heating elements  4 ,  5  and  6  spaced within inner housing  3 , a control tab  7  for lowering and lifting bread carriages  8  and  9  which are guided by vertical slots  10  and  11  respectively in rear wall  12  of inner housing  3 , a control knob  13 , control push bottoms  14 , a base  15 , slot openings  16  and  17  in top wall  18  of inner housing  3  for inserting and removing bread (not shown), and bread support arms  19 ,  20 ,  21  and  22 . Wherein, inner metallic housing  3  forms a heat shield housing for insulating radiation and convention heat dissipated from heating elements  4 ,  5  and  6  during operation. Outer protective housing  2  provides a gap between inner housing  3  and outer housing  2  for natural air cooling so that outer housing  2  is maintained at a temperature not harmful for touching by user during operation. Left planar heating element  4  is provided with heat source (i.e., resistance wires) on right side of its reflective plate only. Center planar heating element  5  is provided with heat sources (i.e., resistance wires) on both sides of its reflective plate. Right planar heating element  6  is provided with heat source (i.e., resistance wires) on left side of its reflective plate only. The space between heating elements  4  and  5  forms a left heating chamber  23  for toasting bread. The space between heating elements  5  and  6  forms a right heating chamber  24  for toasting bread. When breads are inserted through slot openings  16  and  17 , carriages  8  and  9  retain breads at an upper non-toasting position. Tab  7  is then manually lowered down to lower carriages  8  and  9  to a lower toasting position at where all heating elements  4 ,  5  and  6  are automatically energized for toasting breads in heating chambers  23  and  24 . All heating elements  4 ,  5  and  6  are automatically shut off at the end of toasting cycle, upon which carriages  8  and  9  are forced to return to the upper non-toasting position by a biased spring (not shown). It is intended to consume the maximum output capacity of heating elements  4 ,  5  and  6  for toasting breads during toasting cycle. 
     The novel features of the first preferred embodiments of present invention, which are not provided in toaster of prior art, are described as follows. In  FIG. 3 , in mid sections of side walls  25  and  26  of inner housing  3 , side walls  25  and  26  are projected outwardly to form slot cavities  27  and  28  respectively, which are extended in the longitudinal and horizontal direction within inner housing  3 . Slot openings  29  and  30  are provided in front wall  31  of outer housing  2  for inserting a pair of knives (not shown). Behind front wall  31 , rectangular channels (not shown) are integrally connected to back side of front wall  31  around slot openings  29  and  30 , which are extended in rearward direction with the rear ends closely adjacent to and in alignment with slot cavities  27  and  28  respectively. When knives (not shown) are inserted into slot openings  29  and  30 , these channels help to guide the inserted knives to enter into cavities  27  and  28  respectively for heating. These channels are extended long enough so that they restrict lateral movements of the inserted knives, and thus prevent the inserted knives from making contact with heating elements  4  and  6 . It is obvious that various means other than the above described channels can be easily adopted to restrict lateral movement of knife, and prevent it from making contact with heating element. Alternatively, these channels and slot cavities  27  and  28  can be in inclined position so that the inserted knife can be retained in inclined position. It becomes apparent that the above first preferred embodiments of present invention has an advantage of being easily retrofit to a toaster of prior art with minimum modifications and at essentially no additional cost. 
       FIG. 4  is a perspective view of second preferred embodiments of the combined toaster and utensil knife heater unit of present invention.  FIG. 5  and  FIG. 6  are cross sectional views of  FIG. 4 . Many features of the second preferred embodiments of present invention shown in  FIG. 4 through 6  are identical to those of either prior art, or the first preferred embodiments. Again, it is understood that various toasters of prior art may contain various features not shown in  FIG. 4 through 6 .  FIG. 4 through 6  are not intended to show all various features of prior art, or to limit features of the second preferred embodiments of present invention to only those shown in  FIG. 4 through 6 . Other features can be adopted in second preferred embodiments without exceeding the scope of present invention. 
     By comparing drawings among  FIG. 2 through 6 , it becomes apparent that the previously described features of first preferred embodiments, which are identical to those of prior art, are also identical to those of second preferred embodiments. Therefore, these identical features will not be repeatedly described herein. 
     The novel features of the second preferred embodiments of present invention, which are not provided in toaster of prior art, but are altered from the first preferred embodiments of present invention are described as follows. In  FIG. 4 through 6 , the combined unit  32  of second preferred embodiments of present invention is provided with a partition wall  33 , which is equivalent to rear wall  12  of first preferred embodiments in  FIG. 3 . Partition wall  33  is located forward to rear wall  34  of inner housing  35 . Partition wall  33  is provided with numerous slot openings  36  to facilitate convective heat transfer from heating elements  37 ,  38  and  39  to the space between rear wall  34  and partition wall  33 , which forms a heating chamber  40  within inner housing  35 . Slot openings  41  are provided in top wall  42  of inner housing  35  above heating chamber  40 . Knife blade (not shown) can be inserted into heating chamber  40  for heating in a relatively vertical position while knife handle (not shown) is stopped and supported by slot opening  41 . Partition wall  33  prevents the inserted knife from making contact with heating element  37 , 38  or  39 . 
     It is understood that the above described preferred embodiments of present invention are for demonstrating rather than limiting the scope of present invention. Modifications and variations are allowed within scope of present invention. For example, multiple entries and multiple heating chambers for inserting and toasting breads, or multiple entries and multiple heating chambers for inserting and heating knives can be adopted without exceeding the scope of present invention. For another example, various control functions and means for toasting operation can also be adopted without exceeding the scope of present invention. For another example, additional heat sources (i.e. resistance wires) can be adopted to right and left sides of left and right heating elements  4  and  6  respectively in first preferred embodiments for heating knives by direct radiation without exceeding the scope of present invention. For another example, if desired, the combined unit of present invention can be operated for toasting bread/bagel, etc and for heating knife individually rather than simultaneously without exceeding the scope of present invention.