Speed cooking oven with improved radiant mode

A speed cooking with improved gas flow by-pass mechanism for radiant cooking mode. A speed cooking oven with radiant mode is disclosed comprising a cooking cavity, a controller, thermal heating source, blower assembly, air directing means, a vent assembly and a single door gas by-pass system. Hot gas is circulated by the blower motor assembly into the oven cavity where the hot air is directed in a manner wherein a conflicting, colliding turbulent gas flow is directed at a food product providing for the rapid cooking of food products. Alternatively, a single movable door may be utilized that operates between an open position wherein gas flow exhausts from the top of the oven or in the closed position wherein gas is diverted through a conduit and back to the blower mechanism. Gas may therefore flow into the oven cooking cavity or may be diverted around the cooking cavity and maintained at the same temperature, lower temperature or elevated temperature as compared to the cooking cavity without having a direct effect on the food product being cooked.

FIELD OF THE INVENTION

The present invention relates to re-circulating speed cooking ovens with a simplified mechanical mechanism to allow for a radiant mode wherein gas flow may be heated or cooled without directly affecting a food product that may be cooking during such heat up or cool down of the gas flow.

SUMMARY OF THE INVENTION

This invention relates to ovens for cooking of food products. In particular, this invention combines the ability to cook a food product while at the same time providing an improved by-pass mechanism for increasing or decreasing the temperature of the gas flow without directly affecting the food product in the oven cavity. Currently, it is a requirement that in order to increase or decrease the temperature of gas flow available for cooking, a food product being cooked will be impacted by such heat up or cool down of the gas flow. The invention allows for gas flow circulation around the oven cavity without flowing to the food product within the oven cavity.

Additional objects, features and advantages of the present invention will become readily apparent from the following detailed description of the exemplary embodiment thereof, when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

An exemplary version of the speed cook oven with radiant mode is shown inFIGS. 1-4. Appliance101includes an oven cavity102generally defined by a top wall103, a bottom wall104, left side wall105, right side wall106, a back wall194and a front wall195. Oven cavity102also has associated therewith an access opening107through which food items110may be placed within oven cavity102upon cooking rack108a,FIG. 1. Although shown as an oven with one rack108a, the invention may be practiced wherein multiple racks are utilized and although rack108ais shown as a free-standing cooking rack, it may also be supported by the oven side walls. Cooking appliance101has a hinged door109pivotally attached to the oven front for closing the cooking section opening107during cooking operation. Hinged door109may be swung between an open position wherein the door allows access to oven cavity102and a closed position wherein the door covers the opening into oven cavity102. Although illustrated as a hinged door pivotally attached at the left side of the front of the oven, the door may be hinged on the right side, bottom side or top side.

Referring toFIGS. 1-2, the speed cooking oven is comprised of two independent gas transfer systems, described herein as a left gas transfer system and a right gas transfer system wherein left gas transfer system delivers gas to and from the left side of the oven cavity102, and right gas transfer system delivers gas to and from the right side of the oven cavity102. Although each gas transfer system is described separately, the systems are identical in their configuration (although is not required that they be identical) and operation and serve to distribute gas to the respective sides of oven cavity102.

Gas is transferred to and from the left side of oven cavity102via a left gas transfer system, which is comprised of a left gas transfer section115a, extending from the front to back of oven top wall103, along the left side of top wall103. In fluid connection with left gas transfer section115ais top gas egress opening112, which is open to, and in fluid connection with oven cavity102through top wall103. Top gas egress opening112is substantially rectangular, although other geometries may be utilized, and is centrally located within oven top wall103and provides for the passage of gas from oven cavity102into left gas transfer section115a, as gases are removed from oven cavity102through top egress gas egress opening112. Located within left gas transfer section115ais left grease extractor113a. As gas is drawn through top gas egress opening112, the gas passes across left heating means114a, prior to entry in and through left grease extractor113a. Heating means114amay include a direct fired thermal energy source, indirect fired thermal energy, propane, natural gas, electric resistance heating elements, and other thermal means, and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function. After the gas is drawn across left heating means114aand through left grease extractor113a, it is then drawn through left odor filter143aand into left gas transfer section115a. Alternate locations for left odor filter143acan be utilized within the gas flow path and the location of the left odor filter143aadjacent left grease extractor113ais not required. In fluid connection with, and located within left gas transfer section115ais a left gas accelerator, illustrated as left blower wheel116a. Connected to left blower wheel116ais a blower motor shaft, which is driven by a direct shaft from an electric motor. Other means may be employed for coupling blower wheel116ato electric motor, such as belt drive, and the means is not limited to direct drive. Blower wheel116atakes gas from oven cavity102and delivers the gas via gas transfer section117ato the left top side of oven cavity102. Although illustrated as a conventional blower motor, blower motor shaft and blower wheel, other gas pumping means such as a compressor may be utilized to re-circulate gas to and from oven cavity102and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function. Top left gas transfer section117ais in fluid connection with a lower left gas transfer section118avia a left vertical gas transfer section119a. Left vertical transfer section119ais bounded by left side wall105and a left microwave waveguide section120a.

As gas is discharged into top left gas transfer section117a, a selected portion of said gas is directed into a top left discharge section121aby a top left deflecting means122a,FIG. 2shown in the open position. Thereafter the gas is discharged through apertures located within a top left slotted or perforated discharge plate123a. Gas is then distributed into oven cavity102. Apertures100amay be slotted, regularly formed or irregularly formed apertures and are illustrated herein as nozzles,100aand129a, to be discussed herein, and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function as100a,129aand to be discussed further herein100band129b. Gas is distributed through various apertures100alocated within left discharge plate123aand delivered onto the left top and left side portions of the food product110. As gas enters top left gas delivery section121a, said gas may be further deflected via a top left gas deflecting means124aas shown inFIG. 1in the open position. Gas deflecting means124ais pivotally attached to gas discharge plate123a, although, other means for accomplishing said gas deflection may be utilized. For example means such as normally open, normally closed, or normally partially open and normally partially closed switched plates may be used (wherein said plates slide along the inside of perforated plate123ato limit the aperture openings100aof discharge plate123a), and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function. Gas that has not been discharged or deflected into top left gas delivery section121aby gas deflecting means122aflows to lower left gas transfer section118avia vertical transfer section119a. Pivotally attached to waveguide section120ais a lower gas transfer deflection mechanism152a,FIG. 1that operates to limit the amount of gas that is transferred to lower gas transfer section118a. As used herein, the terms “flow control means” “gas deflecting means” “transfer deflection mechanism” and “flow control means” all have the same meaning and refer to means to control gas flow within the oven. Indeed, certain speed cooking operations may call for more gas flow to the lower part of the speed cooking oven, while other operations will call for little or no gas flow to the bottom side of the oven for delivery to the bottom of the food product. In those instances where little or no gas flow is desired upon the bottom surface of the food product, gas transfer deflection mechanism152amay be closed in order to allow all, or substantially all, of the gas flow into top left gas delivery section121a.

Gas that flows to lower left gas delivery section118amay be re-heated, if required, by lower left heating means126a,FIG. 1. After passing over heating elements126a, the gas may be further deflected by deflecting means128a,FIG. 1, shown in the open position. As gas deflecting means128ais rotated, directional control of the gas flow may be further refined, allowing for gas flow to pass through the upper or lower rows of apertures of lower gas plate127aat various positions along food product110bottom surface,FIG. 1. Although gas deflecting means128ais shown as pivotally attached to left slotted or perforated gas discharge plate127a, gas deflecting means128ais not limited to the pivotally attached means illustrated herein, and as described elsewhere herein, applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function. Apertures100a,100b,129aand129bare sized for low pressure drop, while providing and maintaining sufficient gas velocities of approximately 2000 ft/minute to approximately 7000 ft/minute to properly cook the food product, although velocities above 7000 ft/minute may be used and velocities less than 2000 ft/minute may also be utilized. As shown inFIG. 2, the apertures are adjusted such that the majority of the gas is supplied from the top left gas discharge section121a. The resulting imbalance of gas flows between the top left gas flow130aand lower left gas flow132ais desirable because the top flow130amust aggressively remove moisture produced and escaping from the top surface, and top side surface of food product110. The imbalance also serves to heat, brown and/or heat and brown the food product110.

Referring now to the right gas transfer system, gas is transferred to and from oven cavity102via a right gas transfer system, which is comprised of a right gas transfer section115b, which extends from the front to back of oven top wall103, along the right side of top wall103. In fluid connection with right gas transfer section115bis top gas egress opening112, which is open to, and in fluid connection with oven cavity102through top wall103. Located within right gas transfer section115bis right grease extractor113b. As gas is drawn through top gas egress opening112, the gas passes across right heating means114b, prior to entry in and through right grease extractor113b. After the gas is drawn across heating means114band through right grease extractor113b, it is then drawn through right odor filter143band into right gas transfer section115b. Alternate locations for right odor filters143a,143bcan be utilized within the gas flow path and the location of the right odor filter adjacent to right grease extractor113bis not required. In fluid connection with, and located within right gas transfer section115bis a right gas accelerator, illustrated as right blower wheel116b. Connected to right blower wheel116bis a blower motor shaft, which is direct drive with an electric motor. Blower wheel116btakes gas from oven cavity102and delivers the gas via gas transfer section117bto the right top side of oven cavity102. Top right gas transfer section117bis in fluid connection with a lower right gas transfer section118bvia a right vertical gas transfer section119b. Right vertical transfer section119bis bounded by right side wall106and a right microwave waveguide section120b.

As gas is discharged into top right gas transfer section117b, a selected portion of said gas is directed into a top right discharge section121bby a top right deflecting means122b, shown in the open position inFIG. 2. Thereafter the gas is discharged through a top right slotted or perforated discharge plate123binto oven cavity102. Slotted or perforated right discharge plate123bis used to distribute gas leaving top right gas delivery section121bthrough various apertures100binto oven cavity102and onto the right top and side portion of the food product110. As gas enters top right gas delivery section121b, said gas may be further deflected via a top right gas deflecting means124bas shown inFIG. 2. As with124a, gas deflecting means124bis shown as pivotally attached to slotted or perforated discharge plate123b, although other means for accomplishing said gas deflection may be utilized. Gas that has not been discharged or deflected into top right gas delivery section121bby gas deflecting means122bflows to lower right gas transfer section118bvia vertical transfer section119b. Pivotally attached to waveguide section120bis a gas transfer deflection mechanism152b, shown in the open position,FIG. 2, that operates to limit the amount of gas that is transferred to lower gas transfer section118b. Again, as with the left side gas transfer system, certain speed cooking operations may call for more gas flow to the lower part of the speed cooking oven, while other operations will call for little or no gas flow to the lower part of the oven for bottom side browning of the food product. In those instances where little or no gas flow is desired upon the bottom surface of the food product, gas transfer deflection means152bmay be closed, or partially closed, in order to allow little or no gas flow to lower gas delivery section118b.

Gas flow that that is distributed to lower right gas delivery section118bmay be re-heated, if required, by lower right heating means126b,FIG. 2. After passing over heating elements126b, which may or may not be present in every oven, depending upon the particular oven requirements, the gas may be further deflected by deflecting means128b,FIG. 2, shown in the open position. As gas deflecting means128bis rotated, directional control of the gas flow may be further refined, allowing for gas flow to pass through the upper or lower apertures of lower gas plate127bat various positions along food product110bottom surface. Apertures100band129bare sized for low pressure drop, while providing and maintaining sufficient gas velocities of approximately 2000 ft/min to approximately 7000 ft./minute to properly cook the food product although as with other oven functions, gas flows above 7000 ft/minute and lower than 2000 ft/minute may be utilized as needed. Again, as shown inFIG. 2, the top apertures are adjusted such that the majority of the gas is supplied from the top right gas discharge section121b.

As gas flow130ais directed toward the center of oven cavity102from the left side and gas flow130bis directed toward the center of oven cavity102from the right side, the gas flows meet upon the surface of the food product and turbulently mix, conflict and collide, thereby causing high heat transfer and rapid cooking of the food product. This turbulently mixed gas flow directed at the food product can best be described as glancing, conflicting and colliding gas flow patterns that spatially average the gas flow over the surface area of the food product producing high heat transfer and moisture removal rates at the food surface, thereby optimizing speed cooking. The gas flow is directed towards the top, the bottom and the sides of the food product from the left and right sides of the oven cavity and the left and right side gas flows conflict, collide and glance off each other at the food product surface before exiting the oven cavity through top gas egress opening. As used herein the term “mixing” refers to the glancing, conflicting and colliding gas flow patterns that meet at and upon the top surface, the bottom surface and the left and right side surfaces of the food product and produce high heat transfer and speed cooking of the food product due to spatial averaging of the gas flow heat transfer. As used herein, the terms “mix”, “mixing”, “turbulent mix” and “turbulent mixing”. The same mixing of gas flow occurs upon the lower surface and lower side surfaces of food product110by lower gas flows132aand132b,FIG. 1.

In those instances wherein directional control of the gas flow is desired, gas deflecting means122a,122b,124a,124b,128a,128band152aand152b, may be rotated such that gas flow is diverted to selected apertures, thereby effecting a different gas flow pattern and gas mixing upon the food product surface. Additionally, in those instances wherein no bottom side gas flow is desired, gas deflecting means152a,152bmay be closed, thereby allowing for little or no passage of gas flow to the lower portion of the oven cavity. Various other adjustments of gas deflecting means122a,122b,124a,124a,128a,128b,152a,152bare possible and applicant intends to encompass within the language any structure presently existing or developed in the future that allows for combinations of open and closed positions by the various gas flow control means. Gas deflecting (flow control) means122a,122b,124a,124b,128a,128b,152aand152bmay be manually controlled, automatically controlled via controller134or some combination of automatic and manual control and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the function described herein concerning adjustment of the gas deflecting means.

The gas flows within the oven, as well as other functions of cooking appliance are directed by controller314,FIG. 1. Controller134determines, among other things, the velocity of gas flow, which may be constant or varied, or, may be constantly changed throughout the cooking cycle. It may be desired to cook the food product on one velocity throughout the entire cooking cycle, or to vary the gas velocity depending upon conditions such as a pre-determined cooking algorithm, or vary the velocity in response to various sensors that may be placed within the oven cavity, oven return air paths or various other positions within the oven. The location and placement of said sensors will be determined by the particular application of the oven. Additionally, other means may be utilized wherein data is transmitted back to controller134, and thereafter controller134adjusts the cooking in an appropriate manner. For example sensors (temperature, humidity, velocity, vision and airborne chemical mixture level sensors) may be utilized to constantly monitor the cooking conditions and adjust the gas flow accordingly within a cooking cycle, and other sensors not described herein may also be utilized. The speed cooking oven may utilize sensors that are not currently commercially utilized (such as laser, non-invasive temperature sensors and other sensors that are currently too expensive to be commercially feasible), and the speed cooking oven is not limited to those discussed herein, as many sensing devices are known and utilized in the cooking art.

The most efficient utilization of the spent hot gas is by re-circulation of the gas flow through the oven cavity many times during a cooking cycle. During normal speed cooking it may be desirable for one food product to be cooked after another different type of food product (fish followed by pastry) with successive cycles continuing. For example shrimp may be cooked first, followed by a baked product or pastry. Without appropriate filtration, the odors from the shrimp will contaminate the baked product, producing an undesirable taste and odor in the pastry. There exists a need for further air clean-up (in addition to the grease extractors) to further scrub the gas flow of the particles that are not entrained by grease extractors113aand113b. In instances wherein further filtration of the gas flow is desired, odor filters may be placed within the oven cavity.FIG. 2illustrates the use of odor filters143aand143bfor this purpose. Left side odor filter143ais attached within top left gas transfer section117a, downstream of left grease extractor113aand right odor filter143bis attached within right gas transfer section117bdownstream of right grease extractor113b. Odor filters143aand143bare attached in a manner that allows for their easy removal for cleaning and replacement. Gas that flows into the left and right gas transfer systems115aand115bfirst passes through odor filters143aand143b. The gas flow is therefore further scrubbed after passage through grease extractors113aand13bin order to eliminate odors that could interfere with the proper taste of the food product currently being cooked. In some cases it may be beneficial to utilize a second set of odor filters, and these filters may be placed anywhere within the gas flow path of blower wheels116aand116b. Odor filers143a,143bmay be catalytic type elements or other filtration means including, but not limited to activated charcoal, zeolite or ultra violet wavelight light. It is beneficial that the odor filters be comprised of a material, or materials, that effectively scrubs, or cleans the gas flow with a minimal amount of interference with the gas flow velocities. Additionally, it is beneficial that the odor filters be easily removed, easily cleaned and inexpensive for the operator to replace.

During the cooking process it may be desirable to maintain oven cavity temperature at a constant level without the introduction of gas into oven cavity102. For example, the operator may be cooking a delicate pastry and may desire to finish food product110with no gas flow. This may be accomplished with a radiant only mode utilizing an improved gas by-pass system wherein gas flow is not allowed to enter oven cavity102, but is directed to a lower gas chamber408,FIG. 2for by-pass circulation to and from heaters114a,114bvia conduit414,FIG. 4. Appliance101includes lower gas egress opening410, conduit414(FIG. 4), movable door418and actuator420. In the open position, movable door418,FIGS. 1,3, allows gas to circulate in a normal mode for speed cooking. In this instance a single door418blocks the passage of gas through conduit414, thereby forcing all, or substantially all of the gas flow through grease extractors113a,113b, odor filters143a,143band across heaters114a,114bbefore returning to blower wheels116a,116b.

During the radiant cooking mode movable door418is closed by actuator420and worm gear422thereby blocking, or partially blocking, top gas egress opening112. Gas flow is diverted into lower gas egress opening410, through conduit414,FIG. 4and across heaters114a,114bbefore returning to blower wheels116a,116b. Gas flow in this mode does not pass through top egress opening112and does not return to oven cooking cavity102. Depending upon the type of construction, quality of materials and oven specifications, small amounts of gas may leak through door418and into cavity102. Although door418is graphically depicted and described as movable door and worm gear, many methods may be employed to limit and allow gas to pass from lower chamber408, through conduit414and return to blower motors116a,116b, and applicant intends to encompass within the language any structure presently existing or developed in the future that performs the same function as mechanism420,418422.

Radiant mode allows the operator to maintain gas flow at a constant temperature, increase or decrease the temperature of the gas flow without affecting the food product currently being cooked. For example, an operator may currently cooking a food product at a selected temperature but desire to cook the next food product at a higher or lower temperature. In these instances, radiant mode may be utilized and gas flow partially or completely limited oven cavity102. The gas by-passes around oven cavity102but does not, or may not, directly impact the food product, thereby allowing the operator to increase or decrease the temperature of the gas flow and the temperature of the previously described cavity walls. In this manner, the operator gains additional flexibility.

The invention allows for gas flow blockage and diversion with the use of a single movable door that selectively blocks, partially blocks or substantially blocks gas flow through conduit414and egress opening112.

While the exemplary embodiments of the present invention have been shown and described, it will be understood that various changes and modifications to the foregoing embodiments may become apparent to those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the invention is not limited to the embodiments disclosed, but rather by the appended claims and their equivalents.