Abstract:
A countertop cooking device for automating the preparation of food that requires heating, stirring, and the addition of liquid is proposed. The cooking device comprises a body containing a heated cooking pot, one or more separately heated reservoirs, and a means for transferring liquid to the cooking pot from the reservoir(s). The cooking device also comprises a means for stirring the contents of the cooking pot and scraping the inner surfaces of the cooking pot. A means is provided to control the temperatures of the cooking pot and reservoir(s), the sequence and duration of steps, and the stirring of the cooking pot. The sequence and duration of events may be controlled by a predetermined schedule, or based upon information from sensors in the device. The usefulness of the proposed cooking device is demonstrated in this application by describing its use in the preparation of risotto. This device may optionally be used in the preparation of other dishes such as rice and bulgur pilaf, or polenta.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention was previously described in Disclosure Document number 536445, filed with the USPTO on Aug. 11, 2003.  
         [0002]     The inspiration for this device is the automation of the process of making risotto. This device is not limited in its use to only risotto, however. Risotto is a food item typically made by the following steps: 
        (1) Adding chopped onion or shallot to heated fat (butter and/or olive oil) and sauteing     (2) Adding and sauteing rice, preferably arborio, until translucent     (3) Adding a suitable measure of wine and stirring over heat until it is absorbed     (4) Adding suitable measures of stock and stirring over heat until they are absorbed     (5) Completing the dish by removing it from the heat and adding parmesan cheese, salt, pepper, and optionally other ingredients such as seafood, mushrooms, or ham.        
 
         [0008]     The mixture is stirred constantly over heat during this process. It is desirable that during this process the level of liquid never rises above the top of the rice. Traditionally, the rice is cooked al dente, or a little bit uncooked in the middle. The process generally takes 25-35 minutes.  
         [0009]     The dish is desirable in part because of its creamy texture arising from the stirring action, which mixes starch from the rice with the stock as it is reduced. It is desirable as well as for it&#39;s intense flavor due to the large amount of evaporation, which reduces and concentrates the flavor of the stock.  
         [0010]     The utility of this cooking device can be seen in restaurants, where the labor intensity of this dish may preclude fresh preparation during peak serving times. The utility can also be seen in the home, where the labor intensity can also preclude fresh preparation in combination with other dishes, and where the complexity of preparation can be daunting to some home chefs.  
       BRIEF SUMMARY OF THE INVENTION  
       [0011]     The cooking device proposed in this application is meant to automate the aforementioned process of making risotto and other dishes that require heating, stirring, and the addition of liquid. The proposed device will automate the stirring, heating, and liquid addition in the process of making risotto making and other dishes. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0012]      FIG. 1  shows a preferred embodiment of the cooking apparatus (hereafter referred to as ‘device’) in its as-used state, with the lid closed.  
         [0013]      FIG. 2  shows said device with the lid pivoted upward on its hinges, without the removable cooking pot, reservoirs, and stirrer.  
         [0014]      FIG. 3  shows said device with the lid pivoted upward on its hinges, with the removable cooking pot, reservoirs, and stirrer in place for use.  
         [0015]      FIG. 4  shows said device sectioned along line A-A to show the contents of the lid.  
         [0016]      FIG. 5  shows said device sectioned along line B-B to show the contents of the body.  
         [0017]      FIG. 6  shows the preferred embodiment of a paddle.  
         [0018]      FIG. 7  shows the large reservoir, which is similar to the small reservoir except for the size. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0019]     The device of FIGS.  1  to  7  comprises a base assembly  1  and a lid assembly  2 . The lid assembly is shown to be rotatably attached on hinges  18  to allow the exposure of the top of the base assembly and the exposure of the bottom of the lid assembly.  
         [0020]     The base assembly  1  comprises at least two cavities: a cooking pot cavity  44 , a large cavity  6 , and in the preferred embodiment, a small cavity  7 . The cavities have located in them, respectively, a cooking pot heater  8 , a large reservoir heater  29 , and a small reservoir heater  30 . In the preferred embodiment of this device the heaters are of the conventional electrical type.  
         [0021]     The cooking pot cavity  44  is shaped to receive a cooking pot  5 . The large reservoir cavity  6  is shaped to receive a large reservoir  21 . The small reservoir cavity  7  is shaped to receive a small reservoir  22 . The cavities may be thermally insulated (not shown).  
         [0022]     The cooking pot heater  8  receives power from a controller  35  via a cooking pot heater electrical cable  36 . The large heater  29  receives power from the controller  35  via a large heater electrical cable  41 . The small heater  30  receives power from the controller  35  via a small heater electrical cable  37 . A cable in this description is a grouping of one or more electrical wires for transferring electricity for power or signal purposes.  
         [0023]     In the preferred embodiment of the device, the controller  35  receives temperature readings from the cooking pot cavity  44 , the large reservoir cavity  6 , and the small reservoir cavity  7 , via appropriate temperature sensors such as thermocouples or resistance temperature detectors (not shown). The cavities are thermally coupled to the cooking pot or reservoir(s) so that the temperature detectors accurately reflect the temperatures of the contents of the cooking pot or reservoir(s).  
         [0024]     In the preferred embodiment of the device, the base assembly  1  also contains a large reservoir air pump  32 , and a small reservoir air pump,  33 . The large and small reservoir air pumps receive power from the controller  35  via a large reservoir air pump electrical cable  42  and a small reservoir air pump electrical cable  43 .  
         [0025]     The large reservoir air pump  32  forces air through a large reservoir air tube  10 . The tube passes through an air tube hole  19  in the top of the base assembly  1 , through an air tube hole  19  in the bottom of the lid assembly  2 , and connects to a large reservoir air vent  12 .  
         [0026]     When the large reservoir  21  is in the large reservoir cavity  6  and the lid assembly  2  is closed and held fast, a large reservoir gasket  14  will seal on the top of the large reservoir  21 . In this situation air pumped by the large reservoir air pump  32  will force liquid in the large reservoir  21  out a large reservoir spout  50  and into the cooking pot  5 . This setup has the advantage of pumping the liquid without creating the need for cleaning the pump. The sealed lid also reduces the energy required to heat the liquid in the large reservoir  21 .  
         [0027]     The heating of the liquid in a sealed chamber, as in the previous two paragraphs, may create pressure in the air above the liquid, which may force the liquid out of the spout prematurely. A means of preventing this may be required.  
         [0028]     The small reservoir air pump  33  forces air through a small reservoir air tube  11 . The tube passes through an air tube hole  19  in the top of the base assembly  1 , through an air tube hole  19  in the bottom of the lid assembly  2 , and connects to a small reservoir air vent  13 .  
         [0029]     When the small reservoir  22  is in the small reservoir cavity  7  and the lid assembly  2  is closed and held fast, a small reservoir gasket  15  will seal on the top of the small reservoir  22 . In this situation air pumped by the small reservoir air pump  33  will force liquid in the small reservoir  22  out a small reservoir spout  51  and into the cooking pot  5 .  
         [0030]     It is optional that the air tube holes  19  be replaced with sets of mating pneumatic connectors (not shown).  
         [0031]     It is optional that only one air pump be used and a switching means (not shown) be added to route the air to the appropriate vent.  
         [0032]     The base assembly also contains a motor  31 , which receives power from the controller  35  via a motor source electrical cable  40  and a motor return electrical cable  39 .  
         [0033]     The output shaft of the motor  31  is fixed to a motor gear  9 . In the preferred embodiment the motor gear  9  is a bevel gear.  
         [0034]     When the lid assembly  2  is closed and held fast, the motor gear  9  meshes with a motor shaft gear  26  through a motor gear hole  16 . The motor shaft gear  26  is fixed to a shaft  25 , which has fixed to it at the opposite end a paddle shaft gear  27 . The paddle shaft gear  27  meshes with a paddle receiver gear  28 , which is fixed to a paddle shaft receiver  17 . In the preferred embodiment the shaft gears and paddle gear are bevel gears.  
         [0035]     The shaft  25 , is allowed to freely rotate in bearings  24  which are fixed to the lid assembly  2 . The paddle shaft receiver  17  is allowed to freely rotate in a bearing (not shown), which is integral to the lid assembly  2 .  
         [0036]     The paddle shaft receiver  17  accepts a paddle shaft  52  of a paddle  20 . The means of the transfer of torque from the paddle shaft receiver  17  to the paddle  20  is not shown. However many solutions are readily apparent, such as a spline.  
         [0037]     The previous  5  paragraphs describe the drive train of the preferred embodiment, but other means of transferring rotational motion from the motor  31  to the paddle  20  can easily be envisioned and are not excluded from this application.  
         [0038]     In the preferred embodiment of the invention, the motor source electrical cable  40  passes through a current sensing coil  34 . The current sensing coil  34  provides a signal to the controller  35  proportional to the current in the motor source electrical cable  40  via a current sensing coil electrical cable  38 . In this way the controller senses the current that the motor is drawing, and therefore the torque of the motor, and therefore the viscosity of the mixture in the cooking pot.  
         [0039]     The base assembly contains the controller  35 , which controls the various aforementioned actuators and receives data from the aforementioned sensors. It also receives power from a wall outlet via a power cord  23 , and converts the power for use by the various actuators, sensors, and electronics.  
         [0040]     The lid assembly  2  contains part of the drive train, gaskets for sealing the large and small reservoirs  21 ,  22 , and conduits  10 ,  11  for transferring air from the air pumps to the reservoirs as previously described. In the preferred embodiment the lid assembly  2  is attached to the base assembly  1  with hinges. Other means of attachment can easily be envisioned, such as one that allows a linear vertical motion, and are not precluded by this description.  
         [0041]     The lid assembly has a chute  3 , which is a large hole for adding ingredients to the cooking pot  5  during the cooking process. The lid also comprises a plurality of vent holes of which one is numbered  4 , which allow the steam from the cooking process to freely escape. It is desirable that the steam from the cooking process does not condense on the lid assembly and drip back into the cooking pot  5 .  
         [0042]     The paddle comprises a paddle shaft  52  and one or more cooking pot scrapers  53 . The paddle shaft  52  is inserted into the paddle shaft receiver  17  where it is retained by a means not shown, such as a spring-loaded ball bearing which mates with a groove. It also has a means for transmitting rotational motion such as a spline, which is also not shown here.  
         [0043]     The cooking pot scraper(s)  53  are an integral part of the paddle  17  and are firmly fixed to the paddle shaft  52 . They follow the inside form of the cooking pot  5  so that when they rotate they serve both to scrape the sides of the cooking pot  5 , and to stir the mixture therein. They may either be rigid and precisely fitted, or, preferably, be wholly or partially made of a conforming material such as silicone so that they maintain constant contact with the sides and bottom of the cooking pot  5 .  
         [0044]     The cooking pot  5  comprises an open topped container, which, as previously mentioned, has inner surfaces that match the bottom and side contours of the cooking pot scrapers  53 . It is made of a heat conducting and easily cleanable material, such as stainless steel. The cooking pot  5  can be temporarily fixed to the base assembly  1  by a means not shown. When fixed to the base assembly  1 , it will be heated by the cooking pot heater  8 .  
         [0045]     The large  21  and small  22  reservoirs comprise open topped containers with a flange at the top. The flanges mate with the large  14  and small  15  reservoir gaskets when the lid assembly  2  is closed, making an airtight seal. They also have a large  50  and small  51  reservoir spout. The spouts attach at their bases to the bottoms of the reservoirs and, when placed in the large  6  and small  7  cavities, overhang the cooking pot  5  at the top. In this manner when the chamber is sealed and air is forced into the large  12  and small  13  reservoir air vents, liquid is forced into the cooking pot.  
         [0046]     It is optional that a pressure sensor (not shown) sense the pressure in the reservoir(s). The pressure sensor may be used to sense the level or liquid in a reservoir by measuring the head. It may also serve to show that a reservoir is empty if no pressure develops when a pump is actuated.  
         [0047]     The device may optionally comprise a flow meter(s) (not shown) to measure the amount of liquid transferred to the cooking pot from the reservoir(s). These meters may be fully, partially, or not at all incorporated into the reservoir(s).  
         [0048]     The device may optionally comprise a lid closure sensing switch (not shown) for sensing that the lid is closed to prevent actuation of the heaters, air pumps, or motor while the lid is up.  
         [0049]     The device may optionally comprise a latch (not shown) to prevent accidental opening of the lid during the cooking process, to maintain a seal between the lid and reservoir(s), and to ensure that the gears mesh.  
         [0050]     The device will have a user interface (not shown). A suitable user interface would comprise a means for the user to address the controller, such as buttons, switches, or dials; and a means for the controller to address the user, such as an LCD display, lights, or a speaker.  
       METHOD OF USE OF THE INVENTION  
       [0051]     The use of said device will be exemplified by describing its use in making risotto. Other methods that take advantage of the stirring, heating, and fluid transfer functions may be employed to create other dishes. Simpler or modified methods can be envisioned which eliminate or alter some of the steps. The process of making risotto with said device is as follows.  
         [0052]     The user will place the cooking pot  5  and reservoir(s)  21 ,  22  in their respective receptacles  44 ,  6 ,  7 .  
         [0053]     The user will add a pre-determined amount of fat (butter or oil) to the cooking pot  5 .  
         [0054]     The user will add a pre-determined amount of stock to the large reservoir  21 .  
         [0055]     The user will add a pre-determined amount of wine to the small reservoir  22 . Optionally spices, such as saffron, can be included.  
         [0056]     The user will close the lid assembly  2 , bringing the paddle  20  to its operating position in the cooking pot  5 , preventing easy access with the hands to the cooking pot  5 , and sealing the tops of the large and small reservoirs  21 ,  22 . The lid assembly  2  will latch in the preferred embodiment. The lid closure sensing switch, if present, will be actuated.  
         [0057]     The user will activate the device via the user interface.  
         [0058]     The device will bring the stock and wine to just below a simmer, with the controller  35  maintaining the correct temperature with the large and small reservoir heaters  29 ,  30  as actuators, and the large and small reservoir temperature sensors as feedback. If the large or small reservoir  21 ,  22  heats too quickly or above the boiling point of water an empty reservoir is indicated. In this case the process stops and the user is notified via the user interface.  
         [0059]     The controller  35  will heat the cooking pot  5  to a suitable temperature for sauteing, with the cooking pot heater  8  as actuator, and the cooking pot temperature sensor as feedback.  
         [0060]     The interface will indicate to the user to add the onion.  
         [0061]     The user will add the onion through the chute  3  and indicate that they have done so via the user interface.  
         [0062]     The controller  35  will actuate the motor  31 , which will begin rotating the paddle  20  via the drive train  9 ,  26 ,  25 ,  27 ,  28 ,  17 .  
         [0063]     The device will saute the onion in the fat for a period of time.  
         [0064]     The interface will indicate to the user via the user interface to add the rice.  
         [0065]     The user will add the rice through the chute  3  and indicate that they have done so via the user interface.  
         [0066]     The device will saute the onion and rice in the fat for a period of time.  
         [0067]     The device will transfer the wine from the small reservoir  22  to the cooking pot  5  by actuating the small air pump  33 .  
         [0068]     The controller  35  will turn off the power to the small heater  30 .  
         [0069]     The controller  35  will adjust the temperature in the cooking pot  5  to maintain a simmer.  
         [0070]     As the wine evaporates and is absorbed, the mixture becomes more viscous. In the preferred embodiment, the viscosity of the mixture is measured by measuring the current drawn by the motor  31 . The current drawn by the motor  31  is indicated to the controller  35  via the current sensing coil  34 .  
         [0071]     When the controller  35  has determined that the wine has been sufficiently absorbed and evaporated, it will transfer some of the stock from the large reservoir  21  to the cooking pot  5  by actuating the large reservoir air pump  32 .  
         [0072]     Determination of absorption may also be ascertained by a temperature spike, a change in electrical conductivity of the mixture in the cooking pot, a change in color, a change in reflectivity, a change in the height of the mixture in the cooking pot, or a reduction in steam output measured by humidity or turbidity of the atmosphere above the cooking pot.  
         [0073]     When the controller  35  has determined that the stock has been sufficiently absorbed and evaporated, it will transfer some more of the stock from the large reservoir  21  to the cooking pot  5 .  
         [0074]     After a suitable number of iterations of the previous action or when the stock has all been transferred and absorbed, the device will turn off the large reservoir heater  29 , reduce the heat to low in the cooking pot heater  8 , and indicate to the user that the cooking process is finished via the user interface.  
         [0075]     The user will add the final ingredients to the cooking pot.  
         [0076]     The device may continue stirring for a time or until the user indicates that it should stop, maintaining a low to no heat in the cooking pot  5 .  
         [0077]     The user will lift the lid assembly, remove the cooking pot  5 , and serve the risotto.