Food Frying Apparatus

1. Field of the Invention

The present invention relates in general to food preparation. More particularly, this invention relates to apparatus for the deep-fat frying of food and specifically is directed to deep-fat frying apparatus for the frying of food in a retail environment while essentially eliminating the introduction of smoke and/or odor into the surrounding environment.

Although the present invention is applicable for deep-fat frying of numerous types of food products, it has been found to be particularly useful in the frying of frozen french-fry cut potato pieces or breaded-type snack foods in a bar or fast-food counter environment. Therefore, without limiting the applicability of the invention to "frying of frozen french-fry cut potato pieces", the invention will be described in this environment.

Deep-fat fryers or french fryers are widely used in the restaurant business for cooking various food products such as french-fried potatoes, fish and chicken. Typically, such french fryers comprise a deep tank containing a pool of cooking oil in the lower part of the tank with the cooking oil being heated by an immersed electric heating element or by gas flame. The uncooked food product is placed in a basket which is lowered into the heated oil for the desired cooking period. When the product is done, as determined by visual inspection by the restaurant employee or the sound of an audio timer, the basket should be removed from the oil by the employee and the product served to a customer or transferred to a holding station where it is kept warm by heat lamps until served.

With the advent of convenience stores, self-service stations which also handle convenience store items, etc., the need for apparatus to provide hot food products such as french-fried potatoes, fish and chicken has increased. Since there is normally only one employee for such businesses, the apparatus must be of the type which is easily and safely operated by the employee. The apparatus must also be reasonable in cost to the business proprietor, be reliable in its operation and not pollute the surrounding environment.

2. Description of the Prior Art

In the prior art, various machines are known for processing and dispensing small batches or individual servings of a food product, such as french-fried potatoes.

U.S. Pat. No. 3,667,373 discloses an automated coin-operated fried potato machine containing a removable multiple bin supply tray to hold a predetermined quantity of potatoes in each bin and a mechanism to feed the potatoes from successive bins to a hopper which empties into a basket positioned within a cooking bowl. The cooking bowl is pivotally mounted above a storage vessel containing hot cooking oil. An oil lift assembly supplies oil from the storage vessel to the cooking bowl for each batch of potatoes and after the potatoes are fried, the basket is pivoted to dump the fried potatoes into a serving tray fed from a supply stack. The cooking bowl is pivoted to dump the oil through a removable and replaceable filter member and into the storage vessel.

U.S. Pat. No. 3,818,820 discloses an automatic machine for preparing fried potato products which contains a food hopper for storing the potatoes to be fried. A slidably mounted ejection scoop at the bottom of the food hopper dispenses the right amount of potatoes into a basket immersed into a vat of cooking oil. At the end of a predetermined time, the basket is pivoted to drop the fried potatoes into a waiting container. The machine also contains a fan to extract the fumes via a replaceable charcoal filter unit. An automatic fire extinguisher unit is mounted near the fume outlet to extinguish the oil if it should catch fire.

U.S. Pat. No. 3,981,232 discloses a free standing fryer having a fat fryer located within the interior of a cabinet. The cabinet includes a roof section which houses a fan means for extracting air and fumes from the cabinet and forcing the same through filter means which includes charcoal. A fire extinguisher is also disclosed.

Graham (U.S. Pat. No. 971,307) discloses a deep fat fryer including a front-mounted control panel spanning the gap between two forwardly-extending arms of a generally H-shaped tubular frame which forms an opened-topped hinged lid for the fat reservoir. The H-shaped tubular frame is hinged at the rear portion thereof, opposite of the front-mounted control panel. A submersible heating element is attached to the front-mounted control panel and extends downwardly into the cooking oil. When the H-shaped tubular frame is raised upwardly, the heating element is raised out of the cooking oil and moves with the tubular frame.

The present invention as claimed is intended to provide a solution to various prior art deficiencies including the reliability problems associated with the complex automated mechanisms. Also the high initial cost of daily operation and maintenance. In addition, the unacceptable service requirements associated with the highly automated mechanisms. There is also the problem of air pollution by the odor and smoke emitted from some of the machines. Some machines also tend to allow small amounts of cooking oil to exit from the machine. Also, the relative large physical size of the automated units can limit the location of the mechanism as well as the need for an external exhaust. In some prior art devices which store the food, there is a risk of spoilage and contamination of the food. In some units, it is inconvenient and difficult to clean the parts in contact with the oil and oily foods because of the complex automated mechanisms. In addition, many machines are of a design which does not allow for fast and easy removal and replacement of parts and units.

The present invention provides food frying apparatus which may be easily and safely operated to prepare small portions of various food products. The apparatus is a small unit for placement on a counter top without a requirement for an exhaust duct external to the room or for special wiring supplying 220 volt service. Emphasis is placed on ease of use, ease of cleaning and ease of replacement of parts, if needed. The food frying apparatus includes an upright cabinet which is rectangular-shaped in side profile. A fan assembly is mounted in the upper-most portion of the cabinet and exhausts air through the top of the cabinet while drawing air in, through and from the lower portion of the cabinet. A removable filter unit is positioned in the path of air flow upstream from the fan assembly to remove odors, gases, smoke, etc . . . from the air before the air is exhausted back into the room. The removable filter includes a paper filter together with activated charcoal particles configured as an integral unit. A container for holding a supply of cooking oil is located in the lower portion of the cabinet and is positioned in an insulative shroud with a resulting decrease in BTU's required to operate the apparatus. The heater element is embedded in the bottom portion of the container and does not directly contact the cooking oil. A fire extinguisher is automatically activated in case of fire in the apparatus. Means are provided for supporting a cooking basket out of the oil when not being used for cooking. Safety means are provided for removing power to the unit when a fire occurs or when the air within the lower portion of the apparatus exceeds a predetermined temperature. Safety means are provided for removing power to the heater element when the cooking oil exceeds a predetermined temperature or when the container for the cooking oil exceeds a predetermined temperature. Means are included in the apparatus to provide a signal when a predetermined cooking time has elapsed.

Among the advantages offered by the present invention is the compactness, high reliability and safety features provided by the apparatus. The present invention allows the cooking to occur in an inside area without need for an external exhaust and without the need to provide special wiring, such as 220 volt. The present invention allows the simultaneous cooking of two separate batches of food which may be started and timed independently of each other. The present invention provides food frying apparatus which may be disassembled, without use of tools, for easy cleaning and replacement. The physical size of the invention is small so that it is capable of being placed in a large number of locations. Another advantage of the present invention is the low cost of daily operation of the apparatus.

Examples of the more important features of this invention have thus been summarized rather broadly in order that the detailed description thereof that follows may be better understood, and in order that the contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will also form the subject of the claims appended hereto. Other features of the present invention will become apparent with reference to the following detailed description of a presently preferred embodiment thereof in connection with the accompanying drawing, wherein like reference numerals have been applied to like elements, in which:

FIG. 1 is a simplified perspective view of the food frying apparatus according to the present invention;

FIG. 2 is a simplified perspective view of the food frying apparatus according to the present invention with portions of the cabinet being displaced to expose apparatus to view;

FIG. 3 is a simplified perspective view of a cooking basket of the food frying apparatus according to the present invention;

FIGS. 4A and 4B are simplified side elevational views of a basket hanger or holder of the food frying apparatus according to the present invention;

FIG. 5 is a simplified exploded view of the filter according to the present invention;

FIG. 6 is a simplified side elevational view of a container or vat, partially in section, and its relationship to the holder or shroud according to the present invention;

FIG. 7 is a top plan view of the heater and temperature control unit of the present invention; and

FIG. 8 is a simplified schematic diagram of the electrical power and safety elements of the present invention.

Referring now to the drawing and in particular to FIGS. 1 and 2 food frying apparatus according to the present invention is generally referred to by reference numeral 10. The food frying apparatus 10 includes an upright cabinet 12 which is generally rectangular in shape in side profile. Access to the inside portions of upright cabinet 12 is provided by various means which includes a top cover portion 14, a removable front portion 16 and an opening 18 in the lower portion of front portion 16. Opening 18 is coverable by a pivotal tray or door 20 which is attached by hinge means (not shown) to front portion 16 such that tray or door 20 may pivot downwardly to a generally horizontal position as shown (partially) in phantom. Tray or door 20 is supported in the generally horizontal position by two support rods 22 (only one being shown), one support rod 22 being at each end of tray or door 20. The upper end of each support rod 22 is mounted for sliding movement through aperture 24 of support bracket 26 (only one being shown) with each support bracket 26 being mounted to the flange 28 defining opening 18. Positioned below opening 18 is an air inlet opening 30 covered by mesh or screen 32. Near air inlet opening 30 are two timer switches 34 and 36.

Control box 38 is held against the inside surface of side panel 40 by cover 42 and fasteners 44 and includes on/off switch 46, power indicator light 48 and the input connector 50 for power cord 52. Timer switches 34 and 36 are positioned in one end of control box 38.

Top cover portion 14 is pivotable upwardly and includes air outlet opening 54 covered by mesh or screen 56. Top cover portion 14 is pivotally attached to rear panel 58 by hinge means 60 and is supportable in the raised position by support bracket 62. Support bracket 62 is attached between top cover portion 14 and side panel 64. Fan assembly 66 is attached to the underside of the top cover portion 14 such that the exhaust opening of fan assembly 66 is aligned with air outlet opening 54.

Shelf 68 comprising angle-iron bracket material is located at a predetermined height above floor panel 72 and is attached to side panels 40 and 64 and rear panel 58. Shelf 68 supports removable filter means 70 and essentially divides the food frying apparatus 10 into two basic areas. The first or upper area being one where the air contained in the food frying apparatus 10 is cleaned before it is exhausted to the surrounding air through air outlet opening 54. The second or lower area being the food preparation or frying area. Fire extinguisher 74 is attached to rear panel 58 by fastening means 76 and is located in the first or upper area with the head and sensor portion 78 extending through an aperture 80 into the second or lower area. When the head and sensor portion 78 senses a fire, the fire extinguisher 74 is automatically activated to extinguish the fire.

Container or vat 82 sits or fits down into holder or shroud 84 which sits on floor panel 72. Container or vat 82 comprises a material such as an aluminum alloy which readily conducts heat while holder or shroud 84 comprises a material such as high temperature plastic or material which acts as an insulator and does not conduct heat. Holder or shroud 84 is held in place by tabs 86 with a tab 86 being located at each corner of holder or shroud 84 and being attached to floor panel 72. Aperture or cutout 88 is formed in one wall of holder or shroud 84 to allow the heater and temperature control unit 90 to operatively engage container or vat 82. Power and control cable 92 is operatively connected between circuitry in control box 38 and the heater and temperature control unit 90. Heat sensor 94 is positioned in container or vat 82 such that the heat sensor 94 is covered with cooking oil 96. Heat sensor 94 is held in position by clip or keeper 98 which attaches to the corner of container or vat 82 and holder or shroud 84 and holds the capillary tubing 100 in position against the wall of container or vat 82. Capillary tubing 100 is operatively connected between heat sensor 94 and circuitry within control box 38.

A basket hanger or holder 102 is provided for supporting a cooking basket 104 (see FIG. 3) in a position such that the cooking basket 104 is out of cooking oil 96. Cooking basket 104 is generally rectangular in shape and formed of predetermined lengths of wire. Handles 106 are formed as part of the wire forming the periphery of the open or top portion of the cooking basket 104. Cooking basket 104 is shaped to be placed or rested in the cooking oil 96 contained in container or vat 82. Insulation material 108 is formed around each handle 106 so the cooking basket 104 may be handled without the operator/employee's hand or hands being burned. It will be appreciated that cooking basket 104 could be essentially one-half the size shown in FIG. 3 such that two separate cooking baskets 104, with only one handle 106 on each cooking basket 104, could be used to prepare smaller portions of food, either simultaneously or at different times.

The cooking basket 104 is supported out of the cooking oil 96 by the basket hanger or holder 102 by placing the upper-forward edge 110 of cooking basket 104 up into the turned-over edge portion 112 (an inverted U in shape) of the basket hanger or holder 102 and resting the lower-forward edge 114 of cooking basket 104 on shelf or ledge portion 116.

With reference to FIGS. 4A and 4B, the basket hanger or holder 102 is removably attached to holder or shroud 84 in one of the two ways. In FIG. 4A, the basket hanger or holder 102 includes a lower portion 118, below shelf or ledge portion 116, which is formed into a C-shaped section of such dimensions that it clamps to the rear wall 119 of holder or shroud 84. A foot portion 120 (which extends from lower portion 118) of basket hanger or holder 102 extends beneath holder or shroud 84. In FIG. 4B, basket hanger or holder 102 includes a straight lower portion 122 which is inserted in sleeve or pocket 124. Sleeve or pocket 124 is formed as an integral part of the rear wall 119 of holder or shroud 84 or comprises a separate structure which is attached to the rear wall 119 by conventional means.

With reference to FIG. 5, filter means 70 comprises a solid floor portion 126 with apertures 128 formed therein at predetermined locations. A pleated paper filter element 130, cylindrical in shape, is positioned between the solid floor portion 126 and a flat top portion 132. A cylindrical screen 134 is positioned between the solid floor portion 126 and the flat top portion 132 and coaxial with the pleated paper filter element 130 and the aperture 138 formed in the central area of flat top portion 132. Flange 136 may be attached to one end of cylindrical screen 134 so a large area will be present for flat top portion 132 to rest against or flange 136 may be used to attach cylindrical screen 134 to flat top portion 132 by conventional means. Activated charcoal particles 140 are placed in and fill the volume formed and defined by floor portion 126, aperture 142 of pleated paper filter element 130, flat top portion 132 and cylindrical screen 134. Fastening means 144 (see FIG. 2) are passed through apertures 128 of floor portion 126 and apertures 146, which are in alignment with apertures 128, to hold the elements comprising filter means 70 together as a removable unit which rests on shelf 68. The filter means 70 may be easily and readily replaced and the pleated paper filter element 130 and the activated charcoal particles 140 are easily replaced in the filter means 70 when they become dirty or clogged.

With reference to FIG. 6, container or vat 82 (partially in section) is shown with two different embodiments of holder or shroud 84. Holder or shroud 84a comprises 16 gauge stainless steel with the stainless steel folded over to provide a chamber between the inside wall 148 and the outside wall 150 which is filled with insulating material 85. Holder or shroud 84b comprises a high temperature plastic. Terminals 152 and 154 are connected to the ends of heater unit 156 which is formed within the body of container or vat 82. Aperture 158 provides means for insertion of a temperature probe 160 (see FIG. 7) used to monitor the temperature of the container or vat 82.

With reference to FIG. 7, the heater and temperature control unit 90 is shown and includes temperature probe 160 and temperature setting means 162. Terminals 164 and 166 operatively contact terminals 152 and 154 in container or vat 82 to allow power to be applied to the heater unit 156 in container or vat 82. Indicator light 168 provides an indication of when power is being applied to heater unit 156.

With reference to FIG. 8, the electrical portion of the food frying apparatus 10 for activating various elements and for removing power for safety reasons under predetermined conditions is shown. Switch means 170 is associated with the fire extinguisher 74 and is normally closed. Switch means 170 is opened when the head and sensor portion 78 senses a fire in the food frying apparatus 10 and power is removed from the apparatus. Switch means 172 is associated with air temperature sensor 174 (see FIG. 2) and is normally closed. Switch means 172 is opened when the internal air temperature of the food frying apparatus 10 exceeds a predetermined temperature and power is removed from the apparatus. On/off switch 46 provides the manual means for applying power to or removing power from the food frying apparatus 10. Power indicator light 48 lets the operator know when power is applied to the food frying apparatus 10. Motor 176 is in fan assembly 66. Switch means 178 is associated with temperature probe 160 and temperature setting means 162 and is normally closed. When the temperature of container or vat 82 just meets or exceeds the temperature set by the operator on temperature setting means 162, switch means 178 will open to remove the power to heater unit 156. When the temperature of container or vat 82 drops to a predetermined amount below the value set on temperature setting means 162, switch means 178 will close to apply power to heater unit 156, etc. Switch means 180 is associated with heat sensor 94 positioned in the cooking oil 96 to sense the temperature of the oil. Switch means 180 is normally closed but will open to remove power from heater unit 156 if the temperature of the cooking oil 96 exceeds a predetermined temperature. If the cooking oil 96 becomes too hot, a fire could result. Timer switches 34 and 36 are operatively connected to timer circuitry 182 and buzzer 184; their operation will be discussed below.

The food frying apparatus 10 is a small compact unit which can easily be placed on a counter top in a convenience store or a bar establishment. The food frying apparatus can be plugged into any convenient outlet since it operates from 110 volt and does not require 220 volts. At the start of the business period, an employee would check the level of the cooking oil 96 in container or vat 82 and add cooking oil 96 if any was needed. The on/off switch 46 would be placed in the on position which would apply power to heater unit 156, motor 176 in fan assembly 66, power indicator light 48 and indicator light 168 in the heater and temperature control unit 90. Fan assembly 66 would draw air into the second or lower area of the food drying apparatus 10 through air inlet opening 30. The air would then be drawn through the pleated paper filter element 130, then through the activated charcoal particles 140, then through cylindrical screen 134 and out aperture 135 into the first or upper area of the food frying apparatus 10. Filter means 70 removes the smoke particulates, fumes and odors from the cooking oil 96, food etc . . . from the air before the air is discharged backed into the room. From the first or upper area of the food frying apparatus 10, the air is discharged back into the room through air outlet opening 54 by fan assembly 66. When indicator light 168 was cycled off indicating the cooking oil 96 had reached the desired temperature, then the food frying apparatus 10 would be ready to fry food. The operator would place the food to be fried in the cooking basket 104 (either the small or the large double size), open tray or door 20, place the cooking basket 104 into the cooking oil 96 in container or vat 82. Then the operator would close tray or door 20 and push either timer switch 34 or 36; timer switch 34 for the small basket and timer switch 36 for the large basket or for two small baskets. Timer switch 34 activates timer circuitry 182 for approximately two minutes while timer switch 36 activates timer circuitry 182 for approximately four minutes. These times are adjustable for different settings during manufacture. The front of each timer switch 34 and 36 will light when turned on. When the alloted time has passed, timer circuitry 182 causes buzzer 184 to sound for a predetermined time to alert the operator that it is time to remove the cooking basket 104 (containing the cooked food) from the cooking oil 96. The operator opens tray or door 20, removes the cooking basket 104 from the cooking oil 96 and places the cooking basket 104 on basket hanger or holder 102 for a short time to make certain all the cooking oil 96 has drained from the cooking basket 104 and the food contained therein. Then the operator removes the cooking basket 104, serves the food to the customer, places the cooking basket 104 back on basket hanger or holder 102 and closes tray or door 20 until more food needs to be cooked. In the alternative, cooking basket 104 could be placed on tray or door 20.

Thus it is apparent that there has been provided in accordance with this invention, a food frying apparatus which substantially incorporates the advantages set forth above. Although the present invention has been described in conjunction with specific forms thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing disclosure. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is understood that the forms of the invention herewith shown and described are to be taken as the presently preferred embodiments. Various changes may be made in the shape, size and arrangement of parts. For example, equivalent elements may be substituted for those illustrated and described herein, parts may be reversed, and certain features of the invention may be utilized independently of other features of the invention. It will be appreciated that various modifications, alternatives, variations, etc. may be made without departing from the spirit and scope of the invention as defined in the appended claims.