Abstract:
A cooking appliance comprising a container for containing a cooking liquid, an electrical heating element for heating cooking liquid in the container, and a food receptacle supported in the container for angular movement about a horizontal pivot axis. The receptacle has a portion that is perforated to let in cooking liquid in the container for cooking the food articles. A drive mechanism serves to move the food receptacle about the pivot axis. The food receptacle includes a wall extending at least partially around the pivot axis. The wall includes a plurality of fixed traps for trapping and carrying the food articles out of the cooking liquid upon relative upward movement of the receptacle and then allowing the food articles to fall back down upon further upward movement of the receptacle.

Description:
[0001]    The present invention relates to a cooking appliance that is used particularly but not exclusively for frying food.  
         BACKGROUND OF THE INVENTION  
         [0002]    Cooking appliances of the type in general concerned are known, for example as disclosed in U.S. Pat. No. 6,077,555, in which a puddle frame is pivoted about a horizontal axis in a stationary food basket submerged partially in cooking oil for agitating food articles in the basket. The frame inevitably breaks or squashes the food articles. In another known cooking appliance, there is used a cylindrical basket that is rotated centrally about a vertical axis to agitate the food articles contained therein, but a relatively large amount of cooking oil is reeded and the food articles cannot be agitated sufficiently thoroughly.  
           [0003]    The subject invention seeks to mitigate or at least alleviate such problems by providing an improved cooking appliance.  
         SUMMARY OF THE INVENTION  
         [0004]    According to the invention, there is provided a cooking appliance comprising a container for containing a cooking liquid, an electrical heating element associated with the container for heating cooking liquid in the container, and a food receptacle supported in the container for angular movement about a substantially horizontal pivot axis. The receptacle has a portion that is perforated to let in cooking liquid in the container for cooking food articles received in the receptacle. A drive mechanism is included for moving the food receptacle about the pivot axis. The food receptacle includes a wall extending at least partially around the pivot axis. The wall includes a plurality of traps fixed thereto for trapping and carrying the food articles out of the cooking liquid upon relative upward movement of the receptacle and then allowing the food articles to fall back down upon further upward movement of the receptacle.  
           [0005]    Preferably, the food receptacle has a substantially at least part circular cross-section at right angles to the pivot axis, and a central axis coinciding with the pivot axis.  
           [0006]    More preferably, the container has a cross-section that is substantially the same as but marginally larger than that of the food receptacle, together sharing a common central axis.  
           [0007]    It is preferred that the food receptacle comprises a screen basket.  
           [0008]    Preferably, the receptacle portion and wall comprise screen parts.  
           [0009]    It is preferred that the receptacle wall has a general shape that is substantially at least part cylindrical and has a central axis coinciding with the pivot axis.  
           [0010]    Preferably, the traps are spaced apart angularly about the pivot axis.  
           [0011]    In a preferred embodiment, the traps comprise protrusions on an inner surface of the receptacle wall.  
           [0012]    More preferably, the receptacle wall has a substantially at least part cylindrical general shape that extends equidistantly round the pivot axis and has opposite ends, across which ends at least some of the protrusions extend.  
           [0013]    Further more preferably, at least two, upper and lower ones of the protrusions have respective generally triangular cross-sections each having opposite sides, the sides of the upper protrusion being inclined at a relatively larger angle to the receptacle wall than those of the lower protrusion.  
           [0014]    Alternatively, with the receptacle wall extending at least partially around the pivot axis, the traps may comprise recesses in an inner surface of the receptacle wall.  
           [0015]    Preferably, the receptacle wall extends equidistantly at least partially around the pivot axis and are bent in a wavy manner to form the traps.  
           [0016]    In a first preferred embodiment, the food receptacle has a generally semi-cylindrical shape about the pivot axis, and the drive mechanism is adapted to pivot the food receptacle in a reciprocating manner.  
           [0017]    In a second preferred embodiment, the food receptacle has a generally cylindrical shape about the pivot axis, and the drive mechanism is adapted to rotate the food receptacle continuously in one direction. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0018]    The invention will now be more particularly described, by way of example only, with reference to the accompanying drawings, in which:  
         [0019]    [0019]FIG. 1 is a simplified cross-sectional end view of a first embodiment of a cooking appliance in accordance with the invention, the appliance including a semi-cylindrical receptacle for containing food articles;  
         [0020]    [0020]FIG. 2 is a perspective view of the food receptacle of FIG. 1;  
         [0021]    [0021]FIG. 3 is a simplified cross-sectional side view of the cooking appliance of FIG. 1;  
         [0022]    [0022]FIG. 4 is a detailed cross-sectional end view of the cooking appliance of FIG. 1;  
         [0023]    [0023]FIG. 5 is a detailed cross-sectional side view of the cooking appliance of FIG. 3;  
         [0024]    [0024]FIG. 6 is a simplified cross-sectional end view of a second embodiment of a cooking appliance in accordance with the invention, the appliance including a cylindrical receptacle for containing food articles;  
         [0025]    [0025]FIG. 7 is a perspective view of the food receptacle of FIG. 6; and  
         [0026]    [0026]FIG. 8 is a simplified cross-sectional side view of the cooking appliance of FIG. 6. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0027]    Referring initially to FIGS.  1  to  5  of the drawings, there is shown a first cooking appliance  10  embodying the invention, which comprises a rectangular box-like housing  100 , a generally semi-cylindrical stainless steel food receptacle  200  pivotable about a horizontal central axis X 1 , and a drive mechanism  300  for pivoting the receptacle  200 . The housing  100  has a main body  110  housing the food receptacle  200  and driving mechanism  300 , and includes a top lid  120  hinged at one end for closing the body  110 .  
         [0028]    Also housed within the body  110  is a generally deep semi-cylindrical fixed aluminum pot  130  that has a rectangular top opening. The food receptacle  200  lies horizontally inside the pot  130 , together sharing a common horizontal central axis that coincides with the pivot axis X 1 . The drive mechanism  300  is located outside the pot  130 , at one end thereof.  
         [0029]    The food receptacle  200  is a screen basket having a pair of generally semi-circular solid vertical end walls  210  and a generally shallow semi-cylindrical meshed or perforated base wall  220 . The base wall  220  extends horizontally at right angles across the end walls  210  and equidistantly round or about the pivot axis X 1 .  
         [0030]    A rectangular rigid wire frame  230  connects across the tops of the end walls  210  for reinforcement or support, through which food articles, such as potato chips, can be loaded into the basket  200 . The basket  200  has a generally semi-circular cross-section that is flatter than that of the pot  130 , and a marginally smaller diameter for being held in the pot  130  as a rotational sliding fit about the pivot axis X 1 .  
         [0031]    Both basket end walls  210  include respective upstanding apertured lugs  212  aligned with each other along the pivot axis X 1 . A pair of aligned hinges  214  and  216  support the basket  200  by its respective lugs  212  for pivotal movement about the axis X 1  in opposite directions, such that the basket  200  can rotate back-and-forth through an angle of about 70° on either side of the axis X 1 .  
         [0032]    The drive mechanism  300  incorporates a bottom electric motor  310  driving a horizontal output worm gear  320  that is in mesh with an upward train of four double gearwheels  321  to  324  for speed reduction. The upper gearwheel  324  is fixed on a horizontal shaft  325  that includes an eccentric crank pin  326 . The second hinge  216  is a horizontal shaft fitted with a small gearwheel  218 . The drive mechanism  300  includes a third horizontal, middle shaft  330  immediately below the hinge shaft  216 , which is fitted with another small gearwheel  332 . The two gearwheels  218  and  332  are in mesh such that the hinge shaft  216  is rotatable by the middle shaft  330 . The middle shaft  330  includes an eccentric crank pin  334 .  
         [0033]    A connecting rod  340  connects across the two crank pins  326  and  334 . While the first crank pin  326  is driven to turn in one direction by the motor  310  via the gear train  321  to  324 , etc., the rod  340  converts such a rotating action into angular reciprocation for the middle shaft  330  and in turn the hinge shaft  216 . Thus, the hinge shaft  216  turns in opposite directions to swing the food basket  200  back-and-forth inside the pot  130 , through an angle of about 70° on either side of the pivot axis X 1 .  
         [0034]    The pot  130  serves to contain a relatively small amount (say 375 ml) of cooking liquid, such as edible oil, that submerges the lowermost space (as shown by dotted lines in FIG. 1) of the food basket  200  at any angular position thereof. An electrical heater  140  is installed right at the bottom of the pot  130  to heat up the oil (say to 200° C.) for cooking the potato chips.  
         [0035]    The basket  200  includes, on the inner surface of its base wall  220 , a plurality of food traps formed by ridges  222  each having a triangular cross-section. The ridges  222  extend at right angles across the end walls  210  and are spaced apart angularly about the pivot axis X 1 . As part of the base wall  220 , the ridges  222  are likewise meshed or perforated. The ridges  222  are relatively short (in terms of height) and are separated to form co-parallel shallow recesses or channels  224  between them for temporarily trapping or retaining the potato chips.  
         [0036]    During swinging of the food basket  200 , the potato chips are conveyed upwards on the rising side of the basket wall  220 . The chips at the top of the heap will gradually roll or slide (or fall) back down, while those at the bottom remain trapped in the channels  224  as retained by the ridges  222 . When the basket  200  swings to the uppermost position (FIG. 1 or  4 ), most of those bottom chips previously entrapped will have brought up and then allowed to roll back down thereby becoming situated at the top of the heap. Thus, the chips at the bottom (being fried in the oil) are turned upwards to the top (out of the oil), and the same action takes place when the basket  200  swings in the opposite direction. The action repeats in cycle until all the potato chips are cooked.  
         [0037]    The ridges  222  are made not too tall to ensure that all the potato chips that have been lifted can go back down. All the ridges  222 , especially those upper ones on either side that are more clearly so, have a generally triangular cross-section having opposite sides. The sides of upper ridges  222 ′ are inclined at a relatively larger angle to the basket base wall  220  than those of lower ridges  222 ″. The difference in gradient causes the potato chips to move down from different heights and/or at different times, thereby ensuring thorough agitation of the chips. In particular, the chips trapped by the upper ridges  222 ′ will be swung up to a higher level that is sufficient to allow them to turn over before falling down.  
         [0038]    The traps, i.e. ridges  222  and channels  224 , are produced by bending the basket base wall  220  in a wavy manner. In a different construction, the traps may be provided by any other forms of protrusions, such as knobs, bosses or posts, fixed on the basket base wall  220 , which are spaced apart to create cavities therebetween for trapping or catching food articles.  
         [0039]    It is envisaged that the bottom inner surface of the food basket  200  may be left empty (as a wider channel  224 ) or made flat so that the bottom food articles can move about freely without being jammed in place.  
         [0040]    FIGS.  6  to  8  show a second cooking appliance  10 A embodying the invention, which has a construction similar to that of the first cooking appliance  10 , with equivalent parts designated by the same reference numerals suffixed by a letter “A”. The major differences lie in that the food basket  200 A has a generally cylindrical shape and that the drive mechanism  300 A is adapted to rotate the basket  200 A continuously in one direction.  
         [0041]    The food basket  200 A is likewise a screen basket, having a pair of generally circular solid vertical end walls  210 A and a generally cylindrical meshed or perforated peripheral wall  220 A extending horizontally at right angles across the end walls  210 A. The cylindrical basket  200 A is supported centrally for rotation about the pivot axis X 1  for tumbling food articles, such as potato chips, contained therein.  
         [0042]    The peripheral wall  220 A includes a hinged segment  230 A that is openable like a lid to allow food articles to be loaded into the basket  200 A. The wall  220 A is stamped into a wavy shape to form the ridges  222 A and channels  224 A before it is bent into a cylinder and then connected to the end walls  210 A to form the food basket  200 A.  
         [0043]    The aluminum pot  130 A remains generally semi-cylindrical, having a diameter that is marginally larger than that of the basket  200 A for holding the basket  200 A partially (about half) therein as a rotational sliding fit about the pivot axis X 1 . The drive mechanism  300 A likewise incorporates an electric motor and a speed-reduction gearbox, for rotating the food basket  200 A slowly in either one direction.  
         [0044]    In the case of both cooking appliances  10  and  10 A, as the food articles are to be turned and mixed by themselves without the use of any agitator, they can be kept intact without being broken into smaller pieces or squashed. Given that the food articles will be turned continuously, a relatively small amount of cooking liquid can be used, which by reason of its small quantity can be heated up to the required cooking temperature (200° c.) in a relatively short time (5 minutes).  
         [0045]    The invention has been given by way of example only, and various other modifications and/or variations to the described embodiments may be made by persons skilled in the art without departing from the scope of the invention as specified in the accompanying claims.