HK1066709B - Roasting oven - Google Patents

Description

Baking oven

Technical Field

The present invention relates to an infrared baking oven, and more particularly to an apparatus, system and method for baking food products, particularly meat products.

Background

This application relates to improvements to the applicant's own US patents US5,373,777 and US5,560,285, both entitled "roaster". More particularly, the present invention relates to an infrared roaster particularly suitable for rapidly roasting small pieces of food, particularly meat weighing about 50 grams, such as chicken wings. The present invention also differs from all known prior art in that the food to be roasted is shaken and tumbled during roasting, as opposed to being skewered. Thus, during exposure to the high intensity infrared elements, the food is contained within the wire mesh-like cage and the system axis rotates said wire mesh cage.

Other prior art known to the present inventors includes U.S. Pat. No.5,184,540(1993) by Riccio entitled "toasting apparatus with rotisserie". This patent generally discloses a rotisserie oven in which the spit rotates at a greater speed than its drive member. Riccio also employs a reclamation trap between the spit to reclaim juices produced during the cooking of the food.

Also of the prior art is U.S. patent No.4,321,857(1982) to Best, entitled "infrared gas grill," which relates to a grill assembly having primarily the characteristics of a smoking system. Best differs from the present invention in that it employs an open baking method, i.e., a grill type system. Thus Best relies solely on thermal convection during toasting, whereas the present invention, as described more fully below, employs a combination of convective and radiant infrared energy and a narrow window of continuous ventilation for its effective function.

Another prior art includes U.S. Pat. No.4,214,516(1980) to Friedl entitled "barbecue stove," which is commercially known as "Hart Rotisserie. This structure does not employ a heating chamber although an infrared burner is used therein. The system of Friedl exhausts gas and heat through a flue, which is different from the structure of the present invention which circulates high BTU (british thermal unit) value gas within the baking envelope but does not actively discharge the heated gas to the atmosphere. Additionally, Freidl does not employ a high temperature under pressure within the hot chamber at the top of the chamber, thereby creating a toasting zone, i.e., there is no toasting area in the structure or function of Freidl that is relatively high temperature to a lower temperature, but high heat value.

Disclosure of Invention

The baking oven system of the present invention comprises a plurality of elongated food-holding wire mesh cages, each cage having an axis of rotation defined by left and right axial members fixed to respective end walls of the cages. The system further includes a housing having respective front, rear, left and right end walls, a bottom surface and an interior concave upper surface which combine to form a hollow interior enclosure having a substantially concave upper surface, said housing including a hinged panel in at least one of said front or rear walls thereof for selectively removing and inserting said elongated cage into said housing and pressing said cage against journal receiving means located in end panels located at the left and right end walls of said housing. At least one of the front wall or the rear wall further includes an elongated opening, thereby providing continuous, uninterrupted communication between the hollow interior envelope and the atmosphere. The system also includes at least one infrared radiating element located within the envelope of the housing, wherein its radiation is directed toward a center of the inner envelope of the housing located in the concave upper surface of the housing. The system further includes a system shaft journalled between the housing end walls and located near the center of the inner enclosure of the housing and further disposed at a location between one and two cage diameters from the infrared radiation element, wherein the system shaft is rigidly fixed to the end plates on which the cages are journalled. A drive member is coupled to the system shaft for imparting rotational movement to the end plate and the cage journalled on the end plate. The drive means enables food product to traverse an arc or a turn within the cage and thereby enter an enhanced temperature region generally defined by the substantially concave upper surface of the housing.

Preferably, said system axis comprises means for providing a closest rotational path of the outer side wall of each cage to said infrared element of about 8 to 10 cm. Preferably, the radius of curvature of the concave upper surface is about 8 to 12 cm. Preferably, means are also included for internally circulating heated air within said internal envelope of the casing.

An object of the present invention is to provide an infrared ray roasting oven having a high temperature region, a medium temperature region and a low temperature region while using an internal gas of high calorific value.

It is another object of the present invention to provide an infrared roaster that is particularly suitable for quickly roasting small pieces of food, such as chicken wings and diced meat.

It is a further object of the present invention to provide an infrared roaster that relies on the continual balance of exposure of the food to high infrared high temperature radiant energy and exposure to high heat values but lower temperature ambient heating, thereby quickly achieving food roasting without losing the original taste and juices of the food.

It is a further object of the present invention to provide an infrared roaster of the above type which continuously tumbles the food to be roasted while providing continuous aeration whereby the roasted food maintains high tenderness and does not lose the taste or moisture of the food by the rapid roasting process.

The above and still other objects and advantages of the present invention will become apparent from the following brief description of the drawings, detailed description of the invention and appended claims.

Drawings

FIG. 1 is an external perspective view of the system of the present invention;

FIG. 2 is a side view of the system motor and hydrocarbon gas input to the infrared burner of the system;

figure 3 is an internal cutaway view of the hollow inner enclosure of the roaster showing the radiant elements, the system shaft and the cage shaft journal support plate;

FIG. 4 is a top interior view showing the infrared elements of the curved upper roof relative to the furnace;

FIG. 5 is a perspective view of a baking cage used in the present invention; and

fig. 6 is a radial cross-sectional view of the system of the present invention, as viewed along line 6-6 of fig. 1.

Detailed Description

Referring to the external perspective view of fig. 1, it can be seen that the roaster 10 includes a housing 12 having a front wall 14, a rear wall 16, a floor 18, and a concave upper surface 20. See also fig. 6. The housing also includes left and right end walls 22 and 23, respectively. Referring to fig. 1 and 3, the walls are joined together to form a hollow interior envelope including the substantially concave upper surface 20.

A hinged panel or door 24 is shown within a portion of the front wall 14 for selectively removing or inserting a plurality of elongated food-holding wire mesh cages 26 (see fig. 5 and 6), each having an axis of rotation that is collinear with externally mounted left and right shaft members 28. As can be seen in fig. 5, a fixable door 30 is provided for each wire mesh cage 26. These cages typically have a radius in the range of four to six centimeters and may be made of stainless steel wire mesh No. 2. These cages will typically hold approximately 50g of meat pieces, each of which tumbles within each cage while undergoing rotation.

Also preferably provided adjacent the hinge plates 24 are elongated, preferably horizontal openings 32 having a height of about 3 to 4cm for providing continuous, uninterrupted fluid communication between the hollow interior envelope of the housing 12 and the outside atmosphere. It has been found that providing such intermittent communication between the interior of the oven and the external atmosphere maintains a high degree of tenderness of the material without the loss of taste and moisture of the food resulting from the roasting process described below.

The shaft 28 of the food-holding wire cage 26 is secured to journal-receiving members 33 of an end plate 34 (see fig. 3), which is rigidly secured to a system shaft 36 journaled in the left and right end walls 22 and 23. The system shaft is powered by a 0.02 horsepower gear motor 38 shown in fig. 2. That is, a rotary gear output 40 of the motor 38 provides a rotary input to the system shaft 36 through a conventional gear and sprocket arrangement. Also shown in fig. 2 is a natural or synthetic gas input 42 to an elevated infrared radiating element 44 within the upper concave surface 20 of the system housing 12. See fig. 3 and 4. As can be more particularly appreciated with reference to FIG. 6, the infrared radiation elements 44 are preferably directed toward the wire mesh cage 26 so that their closest position to the cage is approximately five centimeters from the cage. It is also noted, among other things, that the radius of rotation of the cage shaft 28 relative to the system shaft 36 is in the range of about 5 to about 9 centimeters. It has been found that the vertical width of the elongated opening 32 is preferably about 50% of the turning radius of the cage. Also, the axis of the opening need not be horizontal.

The output of the infrared element is sufficient to produce a temperature of at least 1000 degrees celsius at a distance of about 8cm from it, i.e. at the closest point of the side walls of the wire mesh cage 26 to the element.

It has been found that optimum results can be achieved if the inner envelope of the outer envelope is provided with a light reflective surface in order to thereby maximise the radiant energy reflected by the inner envelope. In addition, a rotational speed of the end plate 34 and all of the cages 26 relative to the system axis 36 in the range of 6 to 10rpm is optimal to achieve the required balance between: (1) direct radiation roasting is performed with the food, preferably chicken wings or meat products, in its uppermost position relative to the infrared element; and (2) a circulating convection bake over the entire inner enclosure when the cage is in other rotational positions. It will be appreciated that such ambient convection roasting plays an important role in achieving the advantageous and novel cooking results of the present system, wherein it is assumed that the housing of the present invention has a substantially closed nature (except for the elongated atmospheric opening 32) with 80000/hour of BTU being present within the interior of the housing, thereby providing substantially ambient convection roasting when the food within a given cage is not in its highest rotational position. It has been found that infrared radiant energy is primarily used for deep cooking of meats and food products, while convection heating and the high temperatures associated therewith are used for surface cooking and cauterization of food products. The deep toasting and radiant toasting which occurs when the food is in close proximity to the infrared radiation 44, in conjunction with the above tumbling of the food within the cage 26 and the elongate atmospheric opening 32 of the oven, provides a unique match so that the meat or food within the cage is quickly, typically within 3 minutes, toasted to a high tenderness without loss of taste or moisture so that the meat retains its original taste and juice. Thus, at an upper region 46 (see fig. 6) within the concave region 20 of the housing, an enhanced region of concentrated superheated gas is formed by the combination of direct radiation and reflected light caused by the lensing effect of the shiny inner surface of the interior floor of the housing. In addition, the heat generated by the combustion gases within the infrared radiating element 44 will contribute to the high level of BTUs and the temperature inside the enclosure. Thus, the combustion gases provided by the gas input device 42 (see FIG. 2) operate to generate infrared radiation from the infrared radiation element 44 and to generate a substantial amount of heat that is uniformly distributed within the interior of the housing by the fan assembly 48. (see FIG. 6)

Stainless steel drip trays are provided which are heated to very high temperatures by gas burners so that the dripping juices and grease evaporate immediately and are converted into smoke which gives the meat a flavour as it is baked on an open electric grill (chargrill) without causing flames which dry the meat as it is on a bottom-fired grill.

A grease pan 50 (see fig. 3 and 6) is provided at the bottom of the oven 10 for collecting juices, grease, etc. dripping from the rotating food during the toasting process. The grease tray 50 can be easily removed and cleaned between operations of the system.

While there has been shown and described what are at present considered to be the preferred embodiments of the invention, it is to be understood that the invention may be practiced otherwise than as specifically illustrated and described and that certain changes in the form and arrangement of the parts may be made therein without departing from the basic concept or principles of the invention as set forth in the appended claims.

Claims (11)

1. A roaster system, comprising:

(a) a plurality of elongated food-holding wire mesh cages, each cage having an axis of rotation defined by left and right axle members secured to left and right end walls of the cages;

(b) a housing having respective front, rear, left and right end walls, a bottom surface and an interior concave upper surface, the walls and the concave upper surface combining to form a hollow interior enclosure having a substantially concave upper surface, the housing including a hinged panel in at least one of the front or rear walls thereof for selectively removing and inserting the elongated cage into the housing and pressing the cage against journal receiving means located in end plates located at the left and right end walls of the housing, the front wall further including an elongated opening, thereby providing continuous, uninterrupted fluid communication between the hollow interior enclosure and the atmosphere;

(c) at least one infrared radiating element located within the inner shell of the outer shell, the infrared radiating element transmitting infrared radiation into the inner shell of the outer shell, the infrared radiation being directed generally toward a center of the inner shell of the outer shell located in the concave upper surface of the outer shell;

(d) a system shaft journalled between left and right end walls of said housing and located near the center of the inner enclosure of said housing and further disposed at a location between one and two cage diameters from said infrared radiation element, wherein said system shaft is rigidly fixed to said end plates; and

(e) a drive member coupled to said system shaft for imparting rotational movement to said end plate and said cage journalled thereon, thereby causing the food product to traverse an arc of rotation within said cage and thereby enter an enhanced temperature zone generally defined by said substantially concave upper surface of said housing.

2. The system of claim 1, wherein the hollow interior envelope of the housing comprises a light reflective surface.

3. The system of claim 2, wherein the system shaft is rotated by the drive member at a speed of about 6 to 10 rpm.

4. The system of claim 1, wherein the output of the infrared radiation element is sufficient to produce a temperature of at least 1000 ℃ at a distance of about 8cm therefrom.

5. The system of claim 4, wherein said system axis includes means for providing a proximal rotational path of about 8 to 10 centimeters from the outer sidewall of each cage to said infrared element.

6. The system of claim 1, wherein the wire mesh cage has a radius of 4 to 6 centimeters.

7. The system of claim 1, wherein a radius of rotation of the cage axis relative to the system axis is about 5 to 9 centimeters.

8. The system of claim 1, wherein the radius of curvature of the concave upper surface is about 8 to 12 centimeters.

9. The system of claim 1, further comprising means for internally circulating heated air within the internal enclosure of the enclosure.

10. The system of claim 1, wherein the system has a gas input to provide combustion gases to the infrared radiating elements for generating heat and temperature in the enclosure.

11. The system of claim 7, wherein a vertical height of the elongated opening of the front wall is approximately 50% of the turning radius of the cage axis.