Patent Publication Number: US-2011048246-A1

Title: Inner pot assembly for hot-air baking oven and hot-air baking oven having such assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hot-air baking oven, and in particular to an inner pot assembly for a hot-air baking oven. 
     2. Description of Prior Art 
     With the advancement of technology, various kinds of electrical appliances are used in a house to promote the domestic life. In addition to a microwave oven and a toaster, a hot-air baking oven is developed, which includes a pot, a cover and an electric heating module. The interior of the pot is formed into a cooking chamber for receiving food items. The cover is usually made of glass through which a user can observe the cooking condition of the food items received in the pot. The electric heating module generates high-temperature airflow and blows it into the pot. By means of the convection of the high-temperature airflow, the food items can be baked. 
     However, in practice, such a hot-air baking oven still has some problems. When the user intends to bake a number of small-sized food items (such as potato strips) in this hot-air baking oven, only the outer part of the potato strips are completely baked by the high-temperature airflow, but the inner part of the potato strips are not baked sufficiently because they are blocked by the outer part of the potato strips so as to unable to contact the high-temperature airflow sufficiently. In order to solve this problem, the user has to stir the potato strips periodically to make all of the potato strips to be baked uniformly. However, it is inconvenient for the user to stir the food items periodically, and thus the range of the food items to which the aforesaid hot-air baking oven can be applied is restricted. 
     Therefore, it is an important issue for the present Inventor to solve the above-mentioned problems. 
     SUMMARY OF THE INVENTION 
     The present invention is to provide an inner pot assembly for a hot-air baking oven and a hot-air baking oven having such an assembly. A speed-reducing mechanism is provided in the inner pot assembly to drive a stirring member to stir the food items received in the hot-air baking oven, thereby making all the food items to be baked completely. 
     The present invention is to provide an inner pot assembly for a hot-air baking oven, which includes a container body, a rotatable sleeve, a driven shaft, a speed-reducing mechanism and a stirring member. The bottom of the container body has a shaft mount. The rotatable sleeve penetrates the shaft mount to be rotatable with respect to the shaft mount. The driven shaft penetrates the rotatable sleeve to be rotatable with respect to the rotatable sleeve. The speed-reducing mechanism is fixed to the container body and has a speed-reducing gear set driven by the driven shaft and driving the rotatable sleeve to rotate. The stirring member is connected to the rotatable sleeve and received in the container body. The stirring member is driven by the rotatable sleeve. 
     The present invention is to provide an inner pot assembly for a hot-air baking oven, which includes a container body, a rotatable mechanism, a speed-reducing mechanism and a stirring member. The bottom of the container body has a shaft mount. The rotatable mechanism penetrates the shaft mount to be rotatable with respect to the shaft mount. The speed-reducing mechanism is fixed to the container body and has a speed-reducing gear set in mutual transmission with the rotatable mechanism. The stirring member is connected to the rotatable mechanism and received in the container body. The stirring member is driven by the rotatable sleeve. 
     The present invention is to provide a hot-air baking oven having an inner pot assembly, which includes an outer pot, a heating device and an inner pot assembly. The outer pot is formed with a chamber. The heating device has a cover plate covering the outer pot and a motor mounted over the cover plate. The motor has a driving spindle. The inner pot assembly is received in the chamber and includes a container body, a rotatable sleeve, a driven shaft, a speed-reducing mechanism and a stirring member. The bottom of the container body has a shaft mount. The rotatable sleeve penetrates the shaft mount to be rotatable with respect to the shaft mount. The driven shaft penetrates the rotatable sleeve to be rotatable with respect to the rotatable sleeve. The speed-reducing mechanism is fixed to the container body and has a speed-reducing gear set driven by the driven shaft and driving the rotatable sleeve to rotate. The stirring member is connected to the rotatable sleeve and received in the container body. The stirring member is driven by the rotatable sleeve. 
     In comparison with prior art, the present invention has advantageous features as follows: 
     Since the inner pot assembly of the present invention is provided with the driven shaft, the speed-reducing mechanism and the stirring member, and the driven shaft is driven by the driving spindle of the motor of the heating device, it is not necessary to provide an additional motor to drive the driven shaft. Further, the speed-reducing mechanism drives the rotatable sleeve at low speed to rotate, and the rotatable sleeve drives the stirring member to stir the food items received in the inner pot assembly, so that the food items can be baked uniformly. 
     Since the inner pot assembly of the present invention is detachably connected between the heating device and the outer pot of the hot-air baking oven, the inner pot assembly is needed only when the user intends to bake a plurality of small-sized food items such as potato strips. In other words, when the inner pot assembly is not used, the outer pot and the heating device of the hot-air baking oven can still cooperate to bake a large-size food item. Thus, the hot-air baking oven having an inner pot assembly according to the present invention can bake a large range of food items, which increases the practicability of the hot-air baking oven. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the external appearance of the inner pot assembly of the present invention; 
         FIG. 2  is a cross-sectional view showing the inner pot assembly of the present invention; 
         FIG. 3  is an exploded cross-sectional view showing the hot-air baking oven of the present invention. 
         FIG. 4  is an exploded view showing the driving spindle, the coupler and the driven shaft of the present invention; 
         FIG. 5  is an assembled cross-sectional view showing the inner pot assembly, the coupler and the driving spindle; 
         FIG. 6  is an assembled cross-sectional view showing the hot-air baking oven of the present invention; 
         FIG. 7  is an assembled cross-sectional view showing the operating state of the hot-air baking oven of the present invention; and 
         FIG. 8  is an exploded view showing another embodiment of the driving spindle and the driven shaft of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The characteristics and technical contents of the present invention will be explained with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit the present invention. 
     Please refer to  FIGS. 1 and 2 . The present invention provides an inner pot assembly for a hot-air baking oven. The inner pot assembly  10  includes a container body  11 , a rotatable sleeve  12 , a driven shaft  13 , a speed-reducing mechanism  14  and a stirring member  15 . 
     In the present embodiment, the container body  11  is formed of a cylinder  111  having a closed end and a base plate  112  fixed to the bottom surface of the cylinder  111 . The center of the bottom of the cylinder  111  is formed into a hollow post  113 . Further, the base plate  112  is formed with a shaft mount  114  at a position corresponding to that of the hollow post  113 . 
     The rotatable sleeve  12  has a stepped profile, and it penetrates the hollow post  113  to be pivotally connected with the shaft mount  114  and rotatable with respect to the shaft mount  1   14 . 
     The driven shaft  13  is an elongate rod, which penetrates the rotatable sleeve  12  to be rotatable with respect to the rotatable sleeve  12 . A free end of the driven shaft  13  protruding outside the rotatable sleeve  12  is formed with a positioning plane  131 . Alternatively, the rotatable sleeve  12  and the driven shaft  13  in the present embodiment can be assembled together to form a rotatable mechanism. 
     The speed-reducing mechanism  14  comprises a casing  141 , two pivots  142  and a speed-reducing gear set  143 . The casing  141  is used to seal the base plate  112  and allows the bottom end of the driven shaft  13  to be supported therein. Both ends of each pivot  142  are pivotally connected to the casing  141  and the base plate  112 . The speed-reducing gear set  143  is constituted of a plurality of gears and idle wheels with different diameters. One of the gears is fixed to the bottom end of the driven shaft  13 , and the other gear is fixed to the rotatable sleeve  12 . The intermediate idle wheels are connected to the pivots  142  respectively. With the gear speed ratios among the gears and the idle wheels, the speed-reducing mechanism  14  can reduce the speed ratio between the driven shaft  13  and the rotatable sleeve  12 . 
     The stirring member  15  is constituted of a central base  151  and a plurality of blades  152  extending outwards from the central base  151 . The central base  151  is fixedly connected to the rotatable sleeve  12 , so that the stirring member  15  can be driven by the rotatable sleeve  12  and rotatable therewith. 
     Please refer to  FIG. 3 . The present invention further provides a hot-air baking oven having an inner pot assembly. The hot-air baking oven  1  includes an inner pot assembly  10 , a heating device  20  and an outer pot  30 . 
     In the present embodiment, the heating device  20  is an electric heating device for generating hot airflow, which includes a cover plate  21 , a motor  22 , two impellers  23 , an electric heating tube  24  and a protection plate  25 . The cover plate  21  covers above the cylinder  111  of the inner pot assembly  10 . The motor  22  is mounted to the center of the cover plate  21 . The center of the motor  22  extends to have a driving spindle  221 . The distal end of the driving spindle  221  is formed with an outer thread  222 . The two impellers  23  are separated from each other in the vertical direction and are fixed to the middle section of the driving spindle  221  respectively. The electric heating tube  24  is fixed to the cover plate  21  to surround the lower impeller  23 . The protection plate  25  is fixed inside the cover plate  21  at a position corresponding to the lower impeller  23  and the electric heating tube  24 . The protection plate  25  is provided with a through-hole  251  for allowing the driving spindle  221  to penetrate there through. Further, the protection plate  25  is provided with a plurality of venting holes (not shown) at the area excluding the through-hole  251 . 
     The outer pot  30  is also a cylinder having a closed end. The rim of the outer pot  30  is formed with a flange  31  for supporting the cylinder  111  of the container body  11 . The interior of the outer pot  30  is formed with a chamber  32  for allowing the inner pot assembly  10  to be disposed therein. 
     Please refer to  FIGS. 4 and 5 . The hot-air baking oven  1  further includes a coupler  40 . The upper portion of the coupler  40  is provided with an inner thread  41  for threadedly connecting with the outer thread  222  of the driving spindle  221 . The lower portion of the coupler  40  is provided with an insertion hole  42  for allowing the driven shaft  13  to be inserted therein. The inner wall of the insertion hole  42  is formed with a restricting plane  421  for mating with the positioning plane  131  of the driven shaft  13 . With the arrangement, the driven shaft  13  can be driven by the coupler  40  to rotate therewith. 
     Please refer to  FIG. 6 . When in use, the coupler  40  first penetrates the through-hole  251  of the protection plate  25  with the inner thread  41  of the coupler  40  being threadedly connected with the outer thread  222  of the driving spindle  221 . Next, the inner pot assembly  10  is disposed in the chamber  32  of the outer pot  30 , and the inner pot assembly  10  is supported by the flange  31  of the outer pot  30  at a proper height. Then, the cover plate  21  of the heating device  20  covers the container body  11  of the inner pot assembly  10  in such a manner that the insertion hole  42  of the coupler  40  is inserted by the driven shaft  13  and the positioning plane  131  of the driven shaft  13  mates with the restricting plane  421  of the insertion hole  42 . In this way, the hot-air baking oven  1  can be assembled together. 
     Please refer to  FIG. 7 . When in use, the food items to be baked (such as potato strips) are put into the cylinder  111  of the container body  11 . Then, the cover plate  21  of the heating device  20  covers the container body  11  of the inner pot assembly  10  with the insertion hole  42  of the coupler  40  being inserted by the driven shaft  13 . After the heating device  20  is powered, the electric heating tube  24  rises its temperature to generate hot air, and the impeller  23  rotates to blow the hot air toward the food items. The rotation of the driving spindle  221  of the motor  22  drives the driven shaft  13  to rotate accordingly. The rotating speed of the driven shaft  13  is reduced by the gears of the speed-reducing mechanism  14 , thereby making the rotatable sleeve  12  to drive the stirring member  15  and its blades  152  to rotate at a lower speed. Each of the blades  152  stirs the food items slowly, so that the food items received in the cylinder  111  can be heated and baked uniformly. 
     Please refer to  FIG. 8 , which shows another embodiment of the driving spindle  221  and the driven shaft  13  of the present invention. The free end of the driven shaft  13  protrudes from the stirring member  15  (this case is not shown) or is in flush with the top surface of the central base  151  of the stirring member  15  (this case is not shown). The free end of the driven shaft  13  is provided with an insertion slot  132 . Further, the front end of the driving spindle  221  of the motor  22  extends to form an inserting plate  223 , which is inserted into the insertion slot  132 . With this arrangement, the same effect as that of the aforesaid coupler  40  can be achieved. Alternatively, the free end of the driven shaft  13  protrudes outside the stirring member  15  (not shown) and is provided with an insertion slot  132 . 
     According to the above, the inner pot assembly for a hot-air baking oven and a hot-air baking oven having such an assembly according to the present invention really demonstrates industrial applicability, novelty and inventive steps. Further, the structure of the present invention has not been seen in product of the same kind or let in public use. Thus, the present invention conforms to the requirements for a utility model patent.