HK1128211B - Device and method for cooking food on a grill - Google Patents

Description

Apparatus and method for cooking food on a grill

Technical Field

The present invention relates to an apparatus and method for cooking food, particularly meat, on a grill having opposed upper and lower platens wherein the gap spacing between the platens is adjustable during an initial stage and one or more subsequent stages of the cooking time of the food.

Background

A variety of devices for grilling food products are known in the art for grilling meat and other food products. A clamshell grill or grill device is disclosed in U.S. patent nos. 6,016,743, 5910207, 5755150, and 5569478, each of which is incorporated herein by reference. Clamshell grills of this type are commonly used in fast food restaurants to cook meat, for example, by effectively cooking one or more hamburger patties in a short period of time between heated upper and lower cooking surfaces with a fixed gap spacing between the cooking surfaces.

When cooking multiple meat products, conventional grills and methods do not take into account the difference in thickness of each meat product because the gap spacing between the upper and lower cooking surfaces is fixed. Therefore, known grills and cooking methods may not uniformly cook each meat item if there is any significant variation in the thickness of each meat item.

Also, fast food restaurants may freeze their meat in order to keep the meat fresh and to use the meat on an as-needed basis. However, it is well known that known grills and grill cooking methods often sear or burn the surface of the meat during the cooking process due to the initial pressurization of the meat and the large temperature difference between the frozen meat and the heated surface. Furthermore, known grills and cooking methods often cause the cooked meat to lose its tender deliciousness and lose a significant amount of internal moisture because of the high temperature of the heating surface and the cooking time required to thaw and then cook the whole frozen meat.

Accordingly, there is a need for an improved apparatus and method for cooking meat on a grill that improves the taste, texture and mouth feel of the cooked meat product and more evenly cooks a plurality of food items, such as hamburger patties.

Disclosure of Invention

In accordance with one aspect of the present invention, a method of cooking a food item, such as meat, having an initial uncooked thickness on a grill is provided. The method uses different degrees of pressurization determined by predetermined gap spacing to thaw and cook the meat product and to maintain the internal moisture and tenderness of the meat product. The method comprises the following steps: placing generally frozen meat between two opposed platens, the opposed platens each having opposed cooking surfaces, and the opposed cooking surfaces defining an adjustable gap space; the gap spacing between the platens is adjusted so that in an initial stage of the cooking the gap spacing is less than the nominal initial uncooked thickness of the meat and in a second stage of the cooking after the initial stage, the gap spacing between the platens is increased but is still less than the nominal initial uncooked thickness of the meat.

It will be appreciated that meat and other fresh chilled and frozen food products vary somewhat in thickness. Thus, the gap spacing is adjusted based on the standard thickness of the type of food product to be cooked rather than on a per individual food product basis. Thus, reference herein to the initial thickness of meat or other food product is to be understood as referring to the standard initial thickness of such food product to be cooked.

Typically, the meat product is a hamburger patty having upper and lower sides, and the step of placing the meat between two opposed platens includes orienting the hamburger patty so that the upper and lower sides of the hamburger patty are opposite the cooking surfaces of the platens. The orientation of a hamburger patty such as this is typically performed by closing one platen onto the opposite platen in a clam-like manner.

In accordance with another aspect of the invention, the gap spacing during the initial stage of the cooking is in the range of about 75% to 90% of the initial thickness of the meat, preferably about 83% to about 86% of the initial thickness of the meat.

According to another aspect of the invention, during part of the initial phase, the gap spacing is greater than the initial thickness of the meat.

In accordance with yet another aspect of the invention, the gap spacing during the secondary stage of the cooking is in the range of from about 87% to about 97% of the initial thickness of the meat, preferably from about 88% to about 95% of the initial thickness of the meat.

According to yet another aspect of the invention, the gap spacing is greater than the thickness of the meat during the portion of the second stage.

According to yet another aspect of the invention, the meat product has a cooking time, the initial stage comprising from about 6% to about 13% of said cooking time, and the secondary stage comprising from about 87% to about 94% of the cooking time of the meat product.

In accordance with yet another aspect of the present invention, the gap spacing is adjusted by applying a force of about 0.2 to 0.35 pounds per square inch of meat to the one or more platens. The force applied is sufficient to squeeze the meat sufficiently and to reach the desired gap space in the initial stage.

In accordance with another aspect of the present invention, a grill is provided for cooking one or more meat products having an initial uncooked thickness. The grill includes at least one set of opposed platens. Each opposed platen has a platen cooking surface mounted for movement toward and away from the other platen opposite thereto to define an adjustable gap spacing between the platen cooking surfaces. The grill further includes a gap spacing adjustment mechanism for controlling and varying the gap spacing between the platen cooking surfaces during cooking of meat items placed between the platens such that the gap spacing is less than the initial uncooked thickness of the meat during cooking and the gap spacing between the platens is increased but less than the initial uncooked thickness during a secondary stage of cooking subsequent to the initial stage.

According to a further aspect of the invention, a gap spacing adjustment mechanism for controlling and adjusting the gap spacing between the cooking surfaces of the platens includes a drive mechanism associated with at least one of the platens for moving the cooking surface of at least one of the platens toward and away from the cooking surface of the other of the opposed platens to control and adjust the gap spacing between the cooking surfaces of the two platens.

In accordance with yet another aspect of the invention, the drive mechanism is capable of applying sufficient force to a plurality of frozen hamburger patties to reduce the thickness of the frozen hamburger patties by at least 25% of the nominal initial thickness of the patties.

In accordance with yet another aspect of the invention, the gap spacing adjustment mechanism for controlling and adjusting the gap spacing between the platen cooking surfaces further comprises a microprocessor capable of controlling the drive mechanism. The microprocessor can be programmed to cause the drive mechanism to compress the meat item between the platen cooking surfaces during an initial stage of the cooking to a gap spacing in a range of about 75% to about 90% of the initial thickness of the meat item, and thereafter increase the gap spacing between the platens during a second stage of the cooking to a range of about 87% to about 97% of the initial thickness of the meat item.

In accordance with yet another aspect of the present invention, the microprocessor is programmed to cause the drive mechanism to maintain the initial stage gap spacing at about 75% to about 90% of the initial meat thickness for about 6% to about 13% of the total cooking time for the meat item, and thereafter maintain the secondary stage gap spacing at about 87% to about 97% of the initial meat thickness for about 87% to about 94% of the total cooking time.

According to still another aspect of the present invention, there is provided a grill including: opposed upper and lower platens, each having platen cooking surfaces mounted for movement toward and away from each other to define an adjustable gap space between the platen cooking surfaces; and a drive mechanism coupled to the at least one platen for moving the cooking surface of the at least one platen toward and away from the cooking surface of the other platen to control and adjust the gap spacing between the two platen cooking surfaces during cooking of the meat product disposed between the platens such that the gap spacing is less than the initial uncooked thickness of the meat during the cooking, and such that the gap spacing between the two platens is increased but less than said initial uncooked thickness during a secondary stage of the cooking subsequent to the initial stage.

In accordance with another aspect of the invention, the grill includes a microprocessor capable of controlling the drive mechanism. The microprocessor may be programmed to cause the drive mechanism to compress the meat item disposed between the cooking surfaces of the platens to between about 75% and about 90% of the initial meat thickness during an initial stage of the cooking, and thereafter to cause the gap spacing between the cooking surfaces of the platens to between about 87% and about 97% of the initial meat thickness during a secondary stage of the cooking.

In accordance with yet another aspect of the invention, the microprocessor is programmed to cause the drive mechanism to maintain the initial stage gap spacing at about 75% to about 90% of the initial meat thickness for about 6% to about 13% of the total cooking time and thereafter maintain the secondary stage gap spacing at about 87% to about 97% of the initial meat thickness for about 87% to about 94% of the total cooking time.

According to yet another aspect of the invention, the method comprises more than two stages, preferably five stages. At least one point in time during the initial thawing phase, the initial gap spacing of the platens is equal to the initial uncooked thickness of the meat. At least one point in time during the second searing stage, the gap spacing is less than the initial uncooked thickness of the meat. In the third stage of moisture removal, the gap spacing is again equal to the initial uncooked thickness of the meat. In the fourth and fifth cooking stages, the gap spacing is less than the initial uncooked thickness of the meat.

According to yet another aspect of the invention, in a five stage method, the drive mechanism provides an initial gap spacing equal to the thickness of the meat for about 6% of the total cooking time in the first stage, a gap spacing of about 78% to 82% of the thickness of the meat for about 13% of the total cooking time in the second stage, a gap spacing approximately equal to the thickness of the meat for about 1% of the total cooking time in the third stage, a gap spacing of about 88% to 92% of the thickness of the meat for about 40% of the total cooking time in the fourth stage, and a gap spacing of about 91% to 93% of the thickness of the meat for about 40% of the total cooking time in the fifth stage.

Drawings

Other advantages and features of the present invention will become more apparent with reference to the drawings and the following description, in which:

fig. 1 is a perspective view of a grilling apparatus according to the present invention;

fig. 2 is a side view of the grilling apparatus shown in fig. 1;

FIG. 3 is a rear view taken at line 3-3 of FIG. 2;

FIG. 4A is a fragmentary front view of a hamburger patty placed between two opposed platens wherein the gap spacing is greater than the thickness of the hamburger patty;

FIG. 4B is a fragmentary front view of a hamburger patty placed between opposing platens at a point in time during an initial stage of cooking;

FIG. 4C is a fragmentary front view of a hamburger patty placed between opposing plates at a point in time during a second stage of cooking;

FIG. 5 is a flow diagram of a method for cooking meat products according to a two-stage embodiment of the present invention; and

FIG. 6 is a flow diagram of a method for cooking meat products according to a five-stage embodiment of the present invention.

Detailed Description

While embodiments of this invention can take many different forms, specific embodiments thereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.

Referring to the drawings and in particular to FIG. 1, a clamshell grill 10 is shown having a housing 12 and a grill plate 14. The bakeware 14 includes two spaced-apart upper platens 16, 16 'and two opposed spaced-apart lower platens 18, 18'. It should be understood that any number of opposing pairs of upper and lower platens may be used. The housing 12 includes a body portion 20 having four castered leg members 22 so that the grill 10 may be held in a fixed position, such as in a restaurant kitchen where the grill is placed. Typically, the housing 12 is made of stainless steel, such as chrome molybdenum steel, but may be made of any other suitable material.

Each upper platen 16, 16 'includes an upper grilling surface 24, 24' and each lower platen 18, 18 'of grill 10 includes a lower grilling surface 26, 26'. When the opposed pair of platens are in a closed position 28, such as shown in fig. 1 for platens 16, 18, the opposed pair of platens 16, 18 define an adjustable gap space 30 in which one or more meat items may be cooked. The interstitial space 30 determines the degree of compression of the meat product placed therebetween. The platens 16, 16 ', 18' are typically made of a heat treated, polished, and "meat safe" material, such as chrome molybdenum steel, but may be made of any other suitable material.

Inside the housing 12, a lower platen heating member 32, which may be a gas burner or an electric heater, is provided under the lower platens 18, 18' to supply heat to the lower platens. Upper platens 16, 16 ' generally include body portions 34, 34 ' with electrical heaters (not shown) embedded within body portions 34, 34 '. Preferably, the upper platens 16, 16' and the electric heater are made in a cast aluminum process. Alternatively, any other suitable structure for providing heat to upper platens 16, 16 'and lower platens 18, 18' may be used.

To adjust and maintain the predetermined gap spacing 30 of grill 10, the opposing upper and lower platens 16, 16 ', 18' are mounted for relative movement toward and away from each other. In one embodiment, as shown in fig. 2, the housing 12 includes a drive mechanism 36 and a microprocessor (not shown) to control the drive mechanism 36. The microprocessor may be any suitable system known in the art for controlling the movement of any of the components of the drive mechanism 36. The drive mechanism 36 is coupled to at least one of the platens 16, 18 for moving one cooking surface 24, 26 of one of the platens 16, 18 toward and away from the cooking surface 24, 26 of the other platen 16, 18. Whereby the drive mechanism 36 controls and adjusts the gap spacing between the cooking surfaces of the platens.

The microprocessor controls drive mechanism 36 to control the size of gap spacing 30 throughout a predetermined cooking time of the meat product on grill 10. The predetermined time typically includes two or more stages. In a two-stage embodiment of the present invention, the predetermined time includes an initial cooking stage and a secondary cooking stage. At least one point in time during the initial cooking stage, one or both of opposed upper platen 16 and lower platen 18 are moved relative to each other by drive mechanism 36 such that gap spacing 30 is less than the initial uncooked thickness of meat 80. At least at one point in time during the secondary stage of cooking, drive mechanism 36 increases the gap spacing 30 between upper platen 16 and lower platen 18 to be greater than the smallest gap spacing during the initial stage.

In one embodiment, the microprocessor may be programmed to cause the drive mechanism 36 to achieve a gap spacing 30 of about 75% to about 90% of the initial meat thickness for about 6% to about 13% of the total cooking time during the initial stage. In addition, the microprocessor may be programmed to cause the drive mechanism 36 to achieve a gap spacing between the cooking surfaces in the secondary stage of the cooking that is in the range of about 87% to about 97% of the initial thickness of the meat item.

In a multi-stage embodiment of the invention, the predetermined time comprises more than two stages, preferably five stages. At least one point in time during the initial thawing stage, gap spacing 30 is equal to the initial uncooked thickness of meat 80. At least one point in time during the second searing stage, gap spacing 30 is less than the initial uncooked thickness of meat 80. In the third water discharge stage, gap spacing 30 again equals the initial uncooked thickness of meat 80. In the fourth and fifth cooking stages, gap spacing 30 is less than the initial uncooked thickness of meat 80.

In a multi-stage embodiment, the microprocessor can be programmed to cause the drive mechanism 36 to achieve a gap spacing 30 during each stage that approximates the initial meat thickness as shown in the table below, which also shows the approximate percentage of total cooking time for each stage.

TABLE 1

Sequence of stages	Description of the invention	Amount of compression (percent of initial uncooked thickness)	Roasting time
				1	Unfreezing	0％	6％
2	Baking and roasting	78％-82％	13％
				3	Discharge water	0％	1％
4	Baking 1	88％-92％	40％
				5	Baking 2	91％-93％	40％

It should be understood that the drive mechanism 36 may establish a predetermined gap spacing between each set of opposing upper and lower platens. The drive mechanism will therefore run until a predetermined value is reached between the opposed upper and lower platens, which value is typically input to a microprocessor. In achieving the predetermined gap spacing 30, the drive mechanism 36 must apply sufficient pressure to cause the gap spacing to be less than the thickness of the meat. In the present invention, the drive mechanism 36 is capable of applying sufficient force to the plurality of frozen hamburger patties 80 to reduce the thickness of the frozen hamburger patties by at least about 25% of their normal initial thickness. It should also be understood that the applied pressure and the percentage of compression shown in table 1 are neither exact nor constant, and they will vary with the actual thickness of the individual cake or other food product. The numbers shown in table 1 are based on the standard initial thickness of a particular type of tortilla or other food item.

As shown in fig. 2-3 and described in U.S. patent 5,735,150, which is incorporated herein by reference, drive mechanism 36 includes an arm portion 38 and a bearing portion 40 supporting upper platen 16, a feed screw assembly 42, and a motor with a brake 44, a pair of cam rollers 46 rotatably attached to a pair of cam roller mounts 48 at respective locations on arm portion 38, and a microprocessor (not shown).

Arm portion 38 includes shaft supporting portions 50 rotatably supported by bearing portions 40, a platen support 52 supporting upper platen 16, and cam operating portions 54 attached to first and second ends of arm portion 38 for respectively placing shaft supporting portions 50 therebetween. Arm member 38 is designed to be rotated from a position in which plates 16, 18 are generally horizontal as shown in FIG. 4A to an open position 56 of platens 16 ', 18' as shown in FIG. 2. Additionally, bearing portion 40 and arm portion 38 are designed not to rotate counterclockwise beyond closed position 28. After reaching the generally horizontal position, bearing portions 40 and arm portions 38 may be moved vertically up and down as needed to adjust gap spacing 30 while maintaining upper platen 16 parallel to lower platen 18.

The feed screw assembly 42 includes a feed screw shaft 58 that extends vertically through a feed screw nut support 60 and a lower frame 62 disposed on a lower rear portion 64 of the housing 12. The feed screw shaft 58 is designed to be rotatably passed through a feed screw support 65 attached to the lower frame 62. In addition, feed screw shaft 58 is adapted to be rotatably driven by motor 44, which is typically attached to lower frame 62. Additionally, the feed screw assembly 42 includes a feed screw nut 66 that engages the feed screw shaft 58. The feed screw nut 66 is supported by the feed screw nut support 60. The feed screw nut support 60 moves with the feed screw nut 66 as the feed screw nut 66 moves along the feed screw shaft 58. Bearing portion support shafts 68 are respectively mounted on both sides of the feed screw nut support 60. Each bearing portion support shaft 68 is adapted to move vertically through a direct acting bearing 70 and a second direct acting bearing 72 as the feed screw nut support 60 moves.

A respective bearing portion 40 is connected to an upper end 74 of each bearing support shaft 68. Thus, as the bearing support shaft 68 moves up and down, the bearing 40 also moves up and down. A rotary encoder 76 is attached to the lower frame and is rotationally driven by the motor 44 through a belt 78. The rotary encoder 76 generates electrical pulses proportional to its rotation.

The microprocessor of grill 10 includes motor control circuitry that controls the movement of motor 44, counter and comparator circuitry that receives and counts electrical pulses from rotary encoder 76. Also, the microprocessor typically includes a distance setting circuit that sets the desired gap spacing 30 between upper platen 16 and lower platen 18. For example, in operation, a user may operate a position switch disposed on an operating panel below housing 12 to input a desired gap spacing value representing a desired gap spacing 30 between opposing upper platen 16 and lower platen 18 into a comparator circuit via a desired distance setting circuit.

In operation, to open the grill pan from the closed position 28 to the open position 56, a user can activate a lift switch on the upper operating plate of clamshell grill 10. Thereafter, a command to open one platen, preferably upper platen 16 relative to lower platen 18, is input into the motor control circuit. The motor control circuit is responsive to activate the motor 44 to rotate in a designated direction. When motor 44 rotates, feed screw shaft 58 rotates in a prescribed direction and feed screw nut 66 engages feed screw shaft 58 and also moves in a prescribed direction, e.g., upward. Accordingly, feed screw nut support 60 and bearing portion support shaft 68 also move upward together from the lower position.

When bearing portion support shaft 68 is moved upward, bearing portion 40 is also moved upward so that arm portion 38 supported by bearing portion 40 is also moved upward. Arm members 38 thus hold and support upper platen 16 and maintain upper platen 16 in a generally horizontal position relative to being parallel to lower platen 18. Simultaneously with the upward movement, cam operating portions 54 of arm members 38 come into contact with respective cam rollers 46 provided on the rear portion of housing 12. Because the position of cam roller 46 is fixed, the pressing force applied to cam operating portion 54 of arm portion 38 is in the downward (clockwise) direction, thereby rotating arm portion 38 clockwise about shaft 50 supported by bearing portion 40.

As arm member 38 turns, a number of electrical pulses proportional to the number of turns of motor 44 are applied to the counter by rotary encoder 76. For example, an upper limit of the count value corresponding to the bearing portion 40 and the upper plate stroke is set in the counter. The counter incrementally counts the electrical pulses from the rotary encoder 76. When the counter reaches the upper limit of the count value given previously, an instruction to stop the motor is issued to the motor control circuit to stop the driving motion of the motor 44. Thus, upper platen 16 is automatically stopped and maintained in the desired open position.

Thereafter, to move opposed upper and lower platens 16, 18 to closed position 28, the user may input into the microprocessor at least one gap spacing 30 appropriate for the desired meat item or items to be cooked and the amount of cooking time at the selected gap spacing. Any other gap spacing 30 and stage time, such as the secondary stage of cooking described herein, may then be entered.

To close upper platen 16 relative to lower platen 18, a command is sent to the motor control circuit. The motor control circuit rotationally drives the motor 44 in the reverse direction discussed above. Accordingly, feed screw shaft 58 is rotated in the opposite direction of the above discussion and feed screw nut 66, which engages feed screw shaft 58, moves downwardly along feed screw shaft 58. As a result, bearing portion support shaft 68 also moves downward from the upper position. As bearing portion support shaft 68 moves downward, bearing portion 40 also moves downward, and arm portion 38 supported by bearing portion 40 begins to rotate about shaft support portion 50 in the counterclockwise direction together with the corresponding upper platen 16.

The counterclockwise rotation of arm member 38 is effected by the self weight of upper platen 16 and is designed to stop when a generally horizontal position is reached in which upper platen 16 is parallel to lower platen 18 with a clearance space 30 therebetween. When bearing portion support shafts 68 are further moved downwardly after upper platen 16 is parallel to lower platen 18, upper platen 16 is moved downwardly in a direction to reduce gap spacing 30 as needed while maintaining the parallel relationship of upper platen 16 and lower platen 18. In addition, gap spacing 30 may be increased by moving upper platen 16 and lower platen 18 further apart from each other.

While bearing portion support shaft 68 is moving downward, rotary encoder 76 adds the number of electric pulses proportional to the number of revolutions of motor 44 to the counter. The counter counts down the electrical pulses from the rotary encoder 76. In particular, the counter subtracts the number of electrical pulses generated by the rotary encoder 76 from the upper limit of the count value given previously. The counter outputs the current count value to the comparator circuit. A comparator circuit compares this count value with an operator set gap space value. When the two values are equal, a motor brake command is issued to the motor control circuit to stop the driving of the motor 44. Thus, upper platen 16 is automatically stopped and maintained at the desired gap spacing 30. At this point in time, gap spacing 30 between upper platen 16 and lower platen 18 is equal to the desired value set by the operator.

The cooking timer may specify a predetermined selectable cooking time for the meat product. Once the cooking time is complete, upper platen 16 may be automatically raised and rotated to open position 56, with a buzzer alarm or other suitable audio-visual alarm alerting the user to the completion of the cooking time. In addition, the gap spacing may be further increased or decreased as desired. When the operator is notified that the cooking is complete, the cooked meat product can be removed from the grill plate 14. By selecting the appropriate relationship between the pitch of the threads of feed screw shaft 58 and the number of electrical pulses generated by rotary encoder 76, the distance between opposing upper platen 16 and lower platen 18 can be accurately and automatically set to any value, for example, between 5mm and 20 mm.

It should be understood that in the grill and method of the present invention, one of platens 16, 16 ', 18' may be movable while an opposing one of platens 16, 16 ', 18' remains stationary. For example, as shown in FIG. 2, upper platen 16 is movable relative to a stationary lower platen 18. Alternatively, lower platen 18 may be movable relative to upper platen 16 or both upper platen 16 and lower platen 18 may be movable relative to each other. It is critical that any meat product placed between platens 16, 18 not be damaged between the platens 16, 18 when the upper and lower platens 16, 18 are directly opposed to each other in the closed position 28.

Also, it should be understood that the microprocessor and drive mechanism 36 described above constitute only one embodiment of the grill 10 of the present invention. Alternatively, any other microprocessor or drive mechanism 36 may be provided so long as the gap spacing between the opposing upper and lower platens on the grill can be adjusted at predetermined times.

Typically, the meat is frozen when placed on the lower grilling surfaces 26, 26 'of the lower platens 18, 18', and the meat may be any one of hamburger patties, sausage patties, vegetable patties, steak products, or the like, but is typically a frozen hamburger patty 80. Hamburger patties 80 often come in two sizes: 1/4 pound hamburgers weighing about 0.25 pounds before cooking and 1/10 pound hamburgers weighing about 0.10 pounds before cooking. Generally, hamburger patties 80 are arranged in an array, such as the 3 x 3 array shown in fig. 1, on lower cooking surfaces 26, 26 'of lower platens 18, 18' such that hamburger patties 80 are oriented such that the upper and lower surfaces of each hamburger patty 80 are opposite the cooking surfaces of the platens when platens 16, 18 are moved to closed position 28. Once placed on lower platen 18, the hamburger patty is held between the platens and the meat is cooked for a predetermined cooking time.

Figure 5 shows a flow diagram of a two-stage method of cooking meat having an initial uncooked thickness on a grill in accordance with the present invention. The method described below can be performed on a grill of the type described herein or any other grill having two opposed cooking surfaces modified to practice the invention. Other suitable grills include, but are not limited to, those devices disclosed in U.S. Pat. Nos. 6,016,743, 5,910,207, 5,755,150, and 5,569,478, each of which is incorporated herein by reference.

Initially, the meat, which is typically frozen, is placed between two opposed platens 16, 18, each having opposed cooking surfaces 24, 26, the opposed cooking surfaces 24, 26 defining an adjustable gap spacing 30. Gap spacing 30 between platens 16, 18 is adjusted so that during an initial stage of the cooking, the gap spacing is less than the initial uncooked thickness of the meat, and during a secondary stage of the cooking following the initial stage, gap spacing 30 between platens 16, 18 is increased but still less than the initial uncooked thickness of the next meat item. The specific magnitude of each gap spacing during cooking of the meat is discussed in further detail below. Typically, the temperature of upper platens 16, 16 'is set to about 425 ° F and the temperature of lower platens 18, 18' is set to about 355 ° F.

The present invention enables a plurality of meaty products to be cooked sufficiently and uniformly on a clamshell grill or similar device for a predetermined cooking time. The predetermined cooking time includes at least an initial stage and a secondary stage. At least one point in time during the initial stage, one or both of opposed upper platens 16, 16 'and lower platens 18, 18' are moved relative to each other such that gap spacing 30 is less than the initial uncooked thickness of the meat. At least one point in time during the second stage, one or both of upper platens 16, 16 'and lower platens 18, 18' are moved relative to each other such that gap spacing 30 is less than the initial uncooked thickness of the meat but greater than the smallest gap spacing during the initial stage.

Fig. 4A shows a hamburger patty 80 placed between opposing upper and lower platens 16, 18, with upper platen 16 lowered relative to lower platen 18 in fig. 4A, such as by drive mechanism 36 as described herein. As shown in FIG. 4A, upper platen 16 has not yet contacted hamburger patty 80, and thus the height of gap spacing 30a is still greater than the initial thickness of hamburger patty 80. As also shown in FIG. 4A, upper platen 16 is maintained in a substantially horizontal position relative to lower platen 18, so that upper platen 16 can be lowered relative to lower platen 18 while remaining directly opposite lower platen 18.

Figure 4B shows a hamburger patty at some point in time during the initial stage of the cooking cycle. As shown in FIG. 4B, in an initial stage, opposing upper platen 16 and lower platen 18 have a gap spacing 30B that is less than the thickness of hamburger patty 80. The gap space 30b is preferably in the range of about 75 to 90% of the initial thickness of the meat at the initial stage, more preferably 83 to 86% of the initial thickness of the meat.

It can be appreciated that at some point in time during the initial phase, at least for some period of time (whether long or short), hamburger patty 80 must have a gap spacing 30B as shown in fig. 4B. However, the initial phase may include other additional time periods or phases in which the gap spacing is different than the gap spacing shown in FIG. 4B. For example, the initial stage may be characterized by upper and lower platens 16, 18 contacting the upper and lower sides of hamburger patty 80, respectively, during initial cooking to preheat hamburger patty 80, but with a gap spacing greater than that shown in fig. 4B. Thus, the initial stage may be preceded by another stage, namely a stage of preheating the meat. In another embodiment, the gap spacing (not shown) may be greater than the thickness of the meat at some point in time during the initial stage.

The duration of the initial stage may be 0-100% of the predetermined cooking time of the meat product. In one embodiment, the total cooking time of a meat product, such as a hamburger patty, at an initial stage is from about 6% to about 13% of the cooking time of the meat product. It is conceivable that if the initial stage of cooking the meat item lasts for the entire cooking time, the meat will likely be seared on both the upper and lower surfaces due to the initial large temperature difference between the cooking surface and the meat item, and the meat item may become relatively dry during cooking.

The meat product is passed through at least one second stage, which increases the interstitial space 30b, allowing the meat product to relax from its compressed state. In this manner, the meat products being cooked are cooked uniformly throughout the duration and contain their desired moisture and texture without the scorching that is often associated with frozen meat. The second stage, which is typically performed after the initial stage, is illustrated in more detail by fig. 4C. At least at one point in time during the second stage, upper platen 16 and lower platen 18 have a gap spacing 30c that is greater than the minimum gap spacing 30b during the initial stage. At this point in time in the second stage, gap spacing 30c is still less than the initial uncooked thickness of hamburger patty 80. However, it is clear that in the second stage the gap spacing 30c is increased so that the meat can be expanded and cooked evenly without substantial dehydration or charring of the meat. In a preferred embodiment, in the second stage, the gap spacing 30c is in the range of about 87% to 97% of the initial meat thickness, more preferably in the range of about 88% to about 95%.

It can be appreciated that hamburger patties must be cooked for at least some time in the secondary stage, regardless of the length, using gap spacing 30c as shown in figure 4 c. However, the second stage may have other time stages with a gap spacing different from the gap spacing shown in FIG. 4C. For example, the second stage may be characterized by a period of time in which the gap spacing (not shown) of the upper and lower platens is greater than the thickness of the meat at another point in time in the second stage. Also, the second stage is characterized in that the gap spacing can be increased at any point in time within the second stage.

The duration of the secondary stage may be 0-100% of the predetermined cooking time of the meat product. In a preferred embodiment, the cooking time of the meat, such as a frozen hamburger patty, throughout the secondary stage is 87% to about 94% of the cooking time of the meat product.

Also, as shown in figures 4A-C and 5, in a preferred embodiment, hamburger patties 80 are subjected to cooking in an initial stage and then a secondary stage in a continuous stage. However, the predetermined cooking time may also include a plurality of stages. For example, the meat may be subjected to an initial stage, a secondary stage, back to the initial stage, and then cooked in the secondary stage. The invention does not limit the number of stages.

For example, fig. 6 shows a flow chart illustrating a five-stage method of cooking meat on a grill. The method may be performed on a barbecue grill of the type described herein, or the invention may be practiced on any other grill that may be modified to have two opposed cooking surfaces. Each stage is characterized by the gap spacing and the amount of meat compression listed in table 1 above and the preferred cooking time. It has been found that the combination of gap spacing and cooking time in the stages shown in table 1 is particularly advantageous for cooking frozen hamburger patties (with the temperatures of the cooking surfaces described herein) to achieve consistent, uniform cooking without dehydration. Of course, the number of stages and the gap spacing and duration of each stage can be adjusted for different types of meat or other food products.

While the invention has been described with respect to certain preferred embodiments, it will be appreciated that the invention is capable of numerous variations, modifications and rearrangements without departing from the scope of the invention as set forth in the following claims.

Claims (34)

1. A method of cooking a food item having an uncooked standard initial thickness on a grill, comprising the steps of:

placing a food item between two opposed platens, each of said opposed platens having opposed grilling surfaces, and said opposed grilling surfaces defining an adjustable gap spacing;

adjusting the gap spacing between the plates such that the gap spacing is less than the standard uncooked initial thickness of the food product during an initial stage of the cooking, and increasing the gap spacing between the plates during a secondary stage of the cooking after the initial stage and less than the standard uncooked initial thickness of the food product.

2. The method of claim 1, wherein the food item is a hamburger patty having upper and lower sides, and wherein the step of placing the food item between two opposed platens comprises positioning the hamburger patty so that the upper and lower sides of the hamburger patty are opposite the cooking surfaces of the platens.

3. The method of claim 1 wherein said gap spacing during said initial stage of cooking is in the range of about 75% to about 90% of said nominal initial thickness of the food product.

4. The method of claim 1 wherein said gap spacing during said initial stage of cooking is from about 83% to about 86% of said nominal initial thickness of the food product.

5. The method of claim 1 wherein said gap spacing during said secondary stage of the cooking is in the range of about 87% to about 97% of said nominal initial thickness of the food product.

6. The method of claim 5 wherein said gap spacing during said secondary stage of the cooking is in the range of about 88% to about 95% of said nominal initial thickness of the food product.

7. The method of claim 1 wherein the food product is frozen while positioned between the opposed plates.

8. The method of claim 1, wherein the food product has a cooking time, and the initial stage comprises about 6% to about 13% of the cooking time of the food product.

9. The method of claim 1, wherein the food has a cooking time and the secondary stage comprises from about 87% to about 94% of the cooking time of the food.

10. The method of claim 1 wherein said gap spacing is greater than said nominal initial thickness of the food product for a portion of said initial phase.

11. The method of claim 1 wherein said gap spacing is greater than said nominal initial thickness of the food product for a portion of said second stage.

12. The method of claim 1 wherein said gap spacing is adjusted and achieved at said initial stage by applying a force to one or more of said platens sufficient to compress the food product.

13. The method of claim 12, wherein said force required is in the range of about 0.2 to 0.35 pounds per square inch of food product.

14. The method of claim 1, wherein one of the cooking surfaces has a temperature of about 335 ° F and the other of the cooking surfaces has a temperature of about 425 ° F.

15. A multi-stage cooking of a food product having an uncooked standard initial thickness, comprising:

placing a food item between two opposed platens, each of said opposed platens having a grilling surface, said opposed grilling surfaces defining an adjustable gap spacing;

adjusting said gap spacing such that in at least one stage of cooking said gap spacing is approximately equal to said standard uncooked initial thickness of the food product and in at least one subsequent stage said gap spacing is less than said standard uncooked initial thickness of the food product.

16. The method of claim 15 wherein in all stages the temperature of one of the opposing plates is about 335 ° F and the temperature of the other of the opposing plates is 425 ° F.

17. A method of five stage cooking meat having an uncooked standard initial thickness, comprising:

placing meat between two opposed platens, each of said opposed platens having a cooking surface, said opposed cooking surfaces defining an adjustable gap spacing;

said gap spacing is adjusted so that in an initial stage of cooking said gap spacing is approximately equal to said standard initial uncooked thickness of the meat, in a second stage said gap spacing is less than said standard initial uncooked thickness of the meat, in a third stage said gap spacing is approximately equal to said standard initial uncooked thickness of the meat, in a fourth stage said gap spacing is less than said standard initial uncooked thickness of the meat, and in a fifth stage said gap spacing is less than said standard initial uncooked thickness of the meat.

18. The method of claim 17 wherein the gap spacing in the second, fourth and fifth stages is about 78% to about 82%, about 88% to 92%, about 91% to about 93%, respectively, of the standard uncooked initial thickness of the meat.

19. The method of claim 17 wherein the meat product has a cooking time and the first, second, third, fourth and fifth stages comprise about 6%, about 13%, about 1%, about 40% of the cooking time, respectively.

20. The method of claim 17 wherein in all stages, the temperature of one of the opposing plates is about 335 ° F and the temperature of the other of the opposing plates is 425 ° F.

21. A grill for cooking one or more items having an uncooked standard initial thickness, comprising:

opposed upper and lower platens each having a platen cooking surface mounted for movement toward and away from each other to define an adjustable gap space therebetween;

means for controlling and varying the gap spacing between the platen cooking surfaces during cooking of a food item placed between the platens such that during the cooking the gap spacing is less than the nominal initial uncooked thickness of the food item and a secondary stage of the cooking after the initial stage increases the gap spacing between the platens but less than the nominal initial uncooked thickness of the food item.

22. The grill of claim 21 wherein said control and adjustment mechanism includes a drive mechanism associated with at least one of said platens for moving the cooking surface of said at least one plate toward and away from the cooking surface of the other plate to control and adjust the gap spacing between the cooking surfaces of said plates.

23. The grill of claim 22 wherein said food items are a plurality of frozen hamburger patties and said drive mechanism is capable of applying sufficient force to said patties to reduce the thickness of said patties by at least about 25%.

24. The grill of claim 22 wherein said control and adjustment mechanism further comprises a microprocessor capable of controlling said drive mechanism, said microprocessor programmed to cause said drive mechanism to compress meat items between the cooking surfaces of said platens during an initial cooking stage to between about 75% and about 90% of said food item standard initial thickness.

25. The grill of claim 24 wherein the microprocessor is programmed to cause the drive mechanism to achieve a gap spacing between the cooking surfaces of the two platens during a secondary stage of cooking in the range of about 87% to about 97% of the nominal initial thickness.

26. The grill of claim 25 wherein said microprocessor is programmed to cause said drive mechanism to maintain an initial stage platen gap spacing of about 75% to about 90% of a standard initial thickness of said food product for about 6% to about 13% of a total cooking time.

27. The grill of claim 26 wherein said microprocessor is programmed to cause said drive mechanism to maintain a secondary stage platen gap spacing of about 87% to about 97% of a food item's standard initial thickness for about 87% to about 94% of a total cooking time.

28. The grill of claim 21 wherein one cooking surface has a temperature of about 335 ° F and the other cooking surface has a temperature of about 425 ° F.

29. A grill for cooking a food item having an uncooked standard initial thickness, comprising:

upper and lower opposed platens, each said platen having a platen cooking surface mounted for movement toward and away from each other to define an adjustable gap space between said platen cooking surfaces;

a drive mechanism associated with at least one of the platens for moving the cooking surface of the at least one platen toward and away from the cooking surface of the other platen during cooking of a food item placed between the platens to control and adjust a gap spacing between the cooking surfaces of the platens such that the gap spacing is less than the nominal initial uncooked thickness of the food item during cooking and the gap spacing between the platens increases during a secondary stage of cooking after the initial stage and is less than the nominal initial uncooked thickness of the food item.

30. The grill of claim 29 wherein said food items are a plurality of frozen hamburger patties and said drive mechanism is capable of applying sufficient force to said patties to reduce the thickness of said patties by at least about 25%.

31. The grill as recited in claim 29 further comprising a microprocessor capable of controlling the drive mechanism, the microprocessor programmed to cause the drive mechanism to compress food items scaled between the cooking surfaces of the platens during an initial cooking stage to about 75% to about 90% of the standard initial thickness of the food item.

32. The grill of claim 31 wherein said microprocessor is programmed to cause said drive mechanism to obtain said gap spacing of said platens during a secondary stage of cooking in a range of about 87% to 97% of a standard initial thickness of the food product.

33. The grill of claim 32 wherein said microprocessor is programmed to cause said drive mechanism to maintain said gap spacing of said platens during an initial stage of about 75% to about 90% of a standard initial thickness of said food product for about 6% to about 13% of a total cooking time.

34. The grill of claim 33 wherein said microprocessor is programmed to cause a drive mechanism to maintain said gap spacing of said platens during a secondary stage of about 87% to about 94% of the total cooking time of about 87% to about 97% of the nominal initial thickness of the food product.