Abstract:
A frame having a first end and a second end and a plurality of discrete heating stations spaced along the frame between the first end and the second end. A plurality of spits are moved along the frame, each spit supporting a meat product thereon. An advancement and driving mechanism advances the spits from one dicrete heating station to the next in sequential fashion, and is operative to ensure that each spit resides within in the rotisserie for a pre-determined length of time to ensure that the meat is properly cooked, thereby avoiding undercooking and overcooking.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a CIP and claims the priority benefit of U.S. patent application Ser. No. 09/432,837, filed Nov. 1, 1999 issued as U.S. Pat. No. 6,202,545, on Mar. 20, 2001, which is a CIP of U.S. Pat. No. 5,974,956, issued on Nov. 2, 1999 both of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to commercial cooking apparatus and, in particular relates to a staged rotisserie for cooking meat products, such as poultry. 
     BACKGROUND OF THE INVENTION 
     In the general field of industrial cooking and baking, numerous processes and techniques are employed. For example, it is known to process some products using batch cooking operations in which a number of products are placed in an oven, cooked for a time, and then removed, after which a subsequent batch of products is placed in the oven for cooking and the process repeats. 
     It is also known in industrial food processing and cooking to process foods as they are moved along a conveyor line in a rather continuous fashion. For example, cookies are often cooked this way by placing raw cookie dough on a conveyor and conveying the cookie dough through an oven chamber at a predetermined speed to have the cookie dough resident in the oven chamber for a predetermined length of time in order to bake the cookies adequately. This results in baked cookies exiting the downstream end of the oven ready for packaging. 
     In the processed meat trade, there is known U.S. Pat. No. 4,644,857 to Buller-Colthurst, which relates to a food processing chamber and technique for the processing of meat and poultry products. The &#39;857 patent describes a process chamber that is operated in a batch mode such that a batch of products can be introduced into a zone and then simply left stationary during its processing time in that zone. Once that time is up, the batch then can be moved to the next zone and simply left to stand in the next zone, and so on. The &#39;857 patent further describes that in order to move batches or units of products through the zones, a step-wise or batch conveyor system is provided. 
     In the common manner of cooking chicken or other poultry in a restaurant, a rotisserie is used in which poultry are placed on skewers or spits, and the spits are placed within a small oven. The individual spits are rotated about their axis and the group of spits revolve around a central axis to provide even cooking of all of the poultry in the rotisserie. Such a system is shown generally in U.S. Pat. No. 5,471,915 to Lopata. Unfortunately, such a system generally fails to control the residence time of each individual poultry item. Indeed, unless all the poultry items are placed in the rotisserie at the same time and later removed all at once, some poultry items can be cooked for too long, other poultry items can be cooked just the right length of time, while still other poultry items can be cooked not long enough. This is very important inasmuch as even slight undercooking of poultry can pose a serious health risk to consumers by virtue of a failure to completely kill all bacteria that might be present on or in the poultry. Moreover, even slight overcooking of the poultry is highly undesirable as it tends to make the poultry rather tough and dry, because poultry tends to be particularly sensitive to overcooking. 
     Accordingly, it can be seen that a need yet remains for a rotisserie for cooking food items such as poultry, which rotisserie ensures precise control over the cooking of the meat therein to ensure proper doneness of the meat. It is to the provision of such a rotisserie that the present invention is primarily directed. 
     SUMMARY OF THE INVENTION 
     Briefly described, the present invention comprises a staged rotisserie for the controlled cooking of meat, such as poultry. The novel staged rotisserie includes a frame or a housing having an inlet end and an outlet end and has a plurality of discrete heating stations arranged sequentially from the inlet end to the outlet end. The staged rotisserie further includes a number of spits for supporting meat products mounted thereon and support means for supporting the spits in the plurality of discrete heating stations. Further, driving means are provided for driving the spits in rotation and advancement means are provided for periodically advancing the spits from one of the discrete heating stations to a sequentially next one of the discrete heating stations. 
     As spits move toward the outlet end, the spits can be continuously rotated by the driving means. Also, the driving means can be in the form of an endless drive chain driven continuously and engaging sprockets mounted on the spits. Additionally, the staged rotisserie includes an inlet control means for controlling admission of the spits adjacent the inlet end of the housing and being operative to admit a leading spit from a queue of spits adjacent the inlet end. The inlet control means can be activated by operation of the advancement means so that as the spits are advanced, another spit can be admitted through the inlet end. 
     The progression of the spits through the plurality of discrete heating stations can be in a generally descending manner. The advancement means can be operable to lift the spits from a lowered cooking position to a raised advancement position from which the spits can descend by gravity to the next sequential discrete heating station. The advancement means can take the form of a series of lifters, each being operative for lifting a spit, and a cam bar for raising and lowering the lifters. Also, guides can be positioned at each of the discrete heating stations to guide movement of the spits from the lowered cooking position to the raised advancement position. 
     In an alternative form, a walking beam assembly is utilized to advance the spits to the next sequential position, wherein a walking beam on each side of the staged rotisserie is driven in a generally rotational direction. A series of spit rests are carried along the longitudinal length of each walking beam for lifting the ends of each spit, wherein the spits travel in a generally circular direction to the next cooking position. The walking beam assembly can be driven by a motor and a series of pivot arms. Alternatively, the walking beam assembly can be driven by a vertical and a horizontal pneumatic cylinder. As an additional alternative means, a motor driven sprocket chained linked to another sprocket and coupled to crank arms are utilized to drive the walking beam assembly. As a further alternative means, the walking beam assembly can be driven by a set of motor driven links and crank arms. These alternative means for advancing the spits allows the present invention to be utilized on almost any degree of inclination. 
     The invention just described has numerous advantages. For example, the invention eliminates the requirement of an operator to monitor the time that a bird spends in a cooking apparatus or to monitor the internal temperature of the meat. In this way, human error is avoided. Moreover, the invention provides an extremely uniformly cooked product and does so at relatively high volumes (large numbers of poultry can be cooked in this way). The staged rotisserie apparatus also takes up a relatively small amount of space relative to its output of poultry. The staged rotisserie has the ability to vary the cooking temperature at various stages of cooking to effect optimum cooking results. Also, the staged rotisserie is designed to minimize cooking flare-ups and preferably includes side windows and top windows to allow operators and customers to view the cooking birds directly to verify the quality of the cooking period. Importantly, by eliminating the human element in timing the cooking operation or in monitoring an internal cooking temperature in the meat, overcooked and undercooked chicken can be virtually eliminated. The apparatus, because it requires less monitoring, also increases throughput while reducing the number of personnel required to operate the equipment. 
     Accordingly, it is an object of the present invention to provide a rotisserie which reliably cooks poultry to a precise degree of doneness. 
     It is another object of the present invention to provide a rotisserie which eliminates the need to have an operator monitor how long the item is being cooked or the final temperature of the item being cooked. 
     It is another object of the present invention to provide a rotisserie which allows the cooking temperature at various stages of cooking to be varied. 
     It is another object of the present invention to provide a rotisserie which minimizes flame flare-ups. 
     It is another object of the present invention to provide a rotisserie which is capable of producing extremely high volumes of uniformly cooked poultry. 
     It is another object of the present invention to provide a poultry rotisserie requiring a minimum amount of floor space. 
     It is another object of the present invention to provide a rotisserie which allows the customer or operator to visually observe the entirety of the cooking operations. 
     It is another object of the present invention to provide a staged rotisserie that can be utilized on level, inclined or declined surfaces. 
     It is yet a further object of the present invention to provide a staged rotisserie which is simple in its construction, economical to manufacture, and straight forward in use. 
     These and other objects, features and advantages of the present invention will become more apparent to those skilled in the art upon reading the following specification in conjunction with the accompanying drawing figures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a side view of a staged rotisserie according to the present invention. 
     FIG. 1A is a detailed view of the inlet staging area of the staged rotisserie of FIG.  1 . 
     FIG. 2 is a top view of the interior of the staged rotisserie of FIG.  1 . 
     FIG. 3 is perspective view of a staged rotisserie according to an alternative form of the invention. 
     FIG. 4 is a detailed perspective view of the third walking beam assembly of FIG.  3 . 
     FIG. 5 is a side elevation view of the third walking beam assembly of FIG.  3 . 
     FIG. 6 is a side elevation view of the second walking beam assembly of FIG.  3 . 
     FIG. 7 is a side elevation view of a first alternative drive mechanism for the walking beam assembly of FIG.  3 . 
     FIG. 8 is a side elevation view of a second alternative drive mechanism for the walking beam assembly of FIG.  3 . 
     FIG. 9 is a side elevation view of a third alternative drive mechanism for the walking beam assembly of FIG.  3 . 
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Referring now in detail to the drawing figures, wherein like reference numerals represent like parts throughout the several views, FIG. 1 shows a staged rotisserie apparatus  10  according to a preferred form of the invention. The staged rotisserie apparatus  10  includes a housing  11  having an inlet end  12  and an outlet end  13  opposite thereto. The housing also includes an inlet  14  covered by an inlet door  16  generally adjacent the inlet end  12  of the housing. The inlet door  16  is pivotally mounted to the housing  11  at a hinge  17 . In this way, the inlet door  16  can be moved between a lowered position for admitting spits manually through the door and a raised position for closing off the inlet end of the housing. Adjacent the outlet end  13  of the housing  11 , a similar outlet  18  is defined including an outlet door  19  pivotally mounted to the outlet end  13  of the housing  11  by a hinge  21 . 
     The housing  11  is a compact unit that preferably includes viewing windows (not shown) in the sides and/or in the top for allowing an operator or a customer to view the cooking of poultry within the housing. While a totally enclosed housing with sides and a top is depicted in the drawings, in some instances it may be desirable to eliminate or remove one or more of the sides or the top to provide better visibility and improved access. It is pointed out that the invention has ready application in restaurants serving poultry and that it has additional application in factories preparing prepared (pre-cooked) poultry. 
     Within the housing  11 , the poultry are maintained on spits or skewers S 1 -S 8  (referred to collectively as “S”) and are moved from the inlet end  12  toward the outlet end  13 . The housing contains mechanisms for heating the poultry in individual heating stations, for rotating the poultry in the heating stations by rotating the spits, and for advancing the spits containing the poultry from one station to the next in sequential fashion. The housing also includes an inlet staging area  20  for containing a queue of poultry spits waiting to be passed to a first cooking station or stage and a warming output station  30  where fully cooked poultry is held in a warm condition until it is retrieved through the outlet door  19 . 
     Still referring to FIG. 1, it can be seen that the housing  11  contains six (6) discrete heating stages or stations for cooking poultry on spits. While six such discrete cooking stages or stations are depicted in the drawing figures, those skilled in the art will recognize that fewer or greater numbers of heating stages can be suitably employed. Also, by making the cooking stages discrete from one another, they can be individually controlled to expose the poultry to different temperatures at different points during the cooking process. Each cooking station or stage can accommodate one spit S having one or more poultry P mounted thereon. For example, the first cooking stage  31  houses a spit S 3  having mounted thereon poultry P. The other cooking stations  32 - 36  are similar. Each cooking station includes a pair of burners or heating elements, such as heating elements  22  and  23  associated with the first cooking station  31 . Those skilled in the art will recognize that the cooking stations can include briquettes to provide even heating. The heating elements are positioned on either side of the poultry and face the poultry at a slight angle relative to vertical. In this way, the heating elements provide a generally uniform distribution of heat against the sides and bottom of the poultry. As the poultry rotates, all of the surface of the poultry is heated evenly and effectively. The bottom of the heating elements are kept from beneath the poultry so that drippings do not fall onto the heating elements, thereby avoiding flame flare-ups within the rotisserie. Also, the tops of the heating elements are shrouded by covers, such as covers  24  and  25 , to prevent drippings from falling onto the heating elements as the poultry and the spits are moved from one cooking station to a sequential cooking station. The other cooking stations  32 - 36  are similarly arranged with pairs of heating elements and covers for the heating elements (the covers may each cover two heating elements, as shown). Thus, the apparatus  10  includes heating elements  41 - 50  and covers  51 - 55 . 
     As the individual spits S are held within the discrete heating stations or cooking stations  31 - 36 , the spits are continuously rotated by an endless chain  57  driven by an electric motor (not shown). The endless chain  57  engages sprockets mounted on the spits. In this way, as chain  57  is driven in rotation by the motor, all of the spits resting atop the endless chain  57  are rotated accordingly. 
     In a lower portion of the housing  11 , a series of drip pans  61 - 70  are arranged. Each of the drip pans extends across the width of the housing beneath the various cooking stations, the inlet staging area, and the outlet staging area. These drip pans collect drippings from the poultry to allow the drippings to be collected and removed. The drip pans are placed side-by-side and the space between the drip pans is protected by inverted V-shaped diverters, such as diverter  71 . A cam mechanism generally indicated at  72  is positioned above the drip pans  61 - 70  for raising and lowering the spits. The cam mechanism  72  includes a hydraulic or pneumatic cylinder  73  driving a pushrod  74  for pushing and pulling a cam bank  76 . Mounted to the cam bank  76  are a series of identical cams  81 - 86 . 
     Each of the cams  81 - 86  engages a cam roller mounted at the bottom end of a cam follower or lifter  91 - 96 . Each of the lifters  91 - 96  has an upper end which engages one of the spits when the lifter is raised by operation of the cam block  76 . The upper end or tip of the lifters  91 - 96  is slightly inclined to match the angle of incline of the endless chain  57 . The upper end  97  of lifter  91  is different from the upper end of the other lifters and includes a portion residing beyond the guides and which is generally flag-shaped for cooperating with an inlet control mechanism for triggering the admission of one additional spit into the first cooking station. As shown in the figure, the lifters  91 - 96  are guided by guide surfaces such that back and forth motion of the cam block  76  (and therefore of the cams  81 - 86 ) in the lateral direction of direction arrow  98  is translated into simultaneous vertical up and down motion of the lifters  91 - 96  in the direction of direction arrow  99 . 
     Both FIG.  1  and FIG. 1A show the inlet control mechanism  100 , with FIG. 1A showing it in more detail. As shown in FIG. 1A, the inlet control mechanism comprises a generally F-shaped linkage mechanism  101 . The F-shaped linkage mechanism includes a short F-shaped link  102  and a pivot link  103 . The F-shaped link  102  pivots about a pivot axle  104 , while the pivot link  103  pivots about a pivot axle  106 . Two links are coupled to each other by a pin and slot arrangement  107 , with the slot being formed in the bottom leg portion of the F-shaped link  102 , and the pin being attached to the end of pivot link  103 . In this way, motion of the pivot link  103  from its blocking position (shown in solid line) to its admission position (shown in shadow line in FIG. 1A) causes the F-shaped link to pivot in a clockwise direction about pivot axle  104  to assume the position shown in shadow in FIG.  1 A. Thus, the right-most tine of the F-shaped link  102  (as seen from the view in FIG. 1A) dips below the ramp surface  108  and allows a spit S 2  to be admitted past the F-shaped link  102  and to roll or slide down the ramp  108  and fall into the slot of the first cooking station. While the right-most tine allows spit S 2  to advance, the other tine of the F-shaped link  102  continues to hold spit S 1  in position. 
     To allow spit S 1  to advance to the position of S 2  in FIG. 1A, the F-shaped link is rotated in the opposite (counter-clockwise) direction by an unshown portion of the cam mechanism. 
     FIG. 2 shows the internal workings of the staged rotisserie of FIG. 1, shown from inside the housing and looking down from above. FIG. 2 shows the progression of spits having poultry P mounted thereon from the inlet staging area  20  to the outlet staging area  30  in the direction of direction arrow  109 . In particular, FIG. 2 shows the startup of cooking operations and shows a first spit S 5  which has progressed about half-way through the staged rotisserie and is in the third cooking station. The first spit S 5  is followed by second and third spits S 4  and S 3  that are in the second and first cooking stations, respectively. The next spit that would be introduced into the first cooking station would be spit S 2 , currently held in the inlet staging area  20 . That would be followed by fifth spit S 1 , and so on. As the spits, such as spits S 3 -S 5 , are positioned and held in the individual discrete cooking stations, they are rotated continuously by operation of the endless chain  57 . 
     To move the spits from one discrete cooking station to the next, the push rod  74  is retracted by the cylinder  73  to pull all of the cams  81 - 86  toward the cylinder  73 . This has the effect of raising the individual lifters  91 - 96 . The top surfaces of the lifters  91 - 96  engage the underside of the spits, thereby raising the spits with them. Once the spits have cleared the top surface of the inclined ramp  111  (see FIG.  1 ), they roll downwardly along the ramp  111  toward the next discrete cooking station. The cylinder  73  is then operated to extend the push rod  74 , thereby lowering the lifters  91 - 96 . Therefore, when each spit reaches the next cooking station, the spit drops into the slot between the guides and the sprockets on the spits once again are engaged by the endless chain  57 . During this lifting of the spits, the flag-shaped end  97  of the first lifter engages the pivot link  103  of the inlet control mechanism to trigger the inlet control mechanism to admit one more spit. This spit takes the place of the spit that has evacuated from the first cooking station. In this way, the spits are held in a cooking station for a controlled length of time and then are advanced to a sequential next one of the cooking stations and sequenced through the discrete cooking stations from the inlet end toward the outlet end of the staged rotisserie. 
     Alternatively, rather than lifting the spits off of the endless drive chain  57 , the endless drive chain  57  can be lifted by the lifters, thereby taking the spits upwardly as well. Once the spits breach the upper surface of the ramp, they all begin to roll downwardly down the ramp toward the next cooking station, whereupon the drive chain  57  is lowered once again by the cam mechanism. 
     It should be noted that the gravitationally assisted cam mechanism as described above is but one mechanism for advancing the spits S. An alternative embodiment such as that shown in FIGS. 3-6 can be provided wherein the spits S can be advanced without the need for a declined ramp. Referring now to FIG. 3, advancing mechanism  210  is a walking-beam apparatus for advancing the spits S being cooked to the next position in a staged rotisserie cooking machine. Advancing mechanism  210  generally comprises a first walking beam  220 , a second walking beam  230 , a first walking beam support  240 , a second walking beam support  246 , a third walking beam support  252 , a fourth walking beam support  258 , a first crank arm  266 , a second crank arm  276 , a third crank arm  286 , a fourth crank arm  296 , a first cross-shaft  310 , a second cross-shaft  320 , a first gearbox  330 , a second gearbox  340 , a propeller shaft  360 , a first series of spit rests  370 , a second series of spit rests  380  and a motor  390 . 
     More specifically, the first walking beam  220  and the second walking beam  230  are preferably elongated and rectangular shape, wherein each has a first end  222  and  232 , respectively, a second end  224  and  234 , respectively, a first longitudinal edge  226  and  236 , respectively, and a second longitudinal edge  228  and  238 , respectively. The first walking beam support  240  has a first end  242  and a second end  244 , wherein the first end  242  is rigidly attached proximal to the first end  222  of the first walking beam  220  via bolts or any other known attaching means, and wherein the second end  244  is pivotably attached to a first end  268  of the first crank arm  266  via a first half-wing bolt  274  or any other known pivotable attaching means. 
     The second walking beam support  246  has a first end  248  and a second end  250 , wherein the first end  248  is rigidly attached proximal to the second end  224  of the first walking beam  220  via bolts or any other known attaching means, and wherein the second end  250  is pivotably attached to a first end  278  of the second crank arm  276  via a second half-wing bolt  284  or any other known pivotable attaching means. 
     The third walking beam support  252  has a first end  254  and a second end  256 , wherein the first end  254  is rigidly attached proximal to the first end  232  of the second walking beam  230  via bolts or any other known attaching means, and wherein the second end  256  is pivotably attached to a first end  288  of the third crank arm  286  via a third half-wing bolt  294  or any other known pivotable attaching means. 
     The fourth walking beam support  258  has a first end  260  and a second end  262 , wherein the first end  260  is rigidly attached proximal to the second end  234  of the second walking beam  230  via bolts or any other known attaching means, and wherein the second end  262  is pivotably attached to a first end  298  of the fourth crank arm  296  via a fourth half-wing bolt  304  or any other known pivotable attaching means. 
     The first crank arm  266  has a throughhole  272  formed proximal to a second end  270  thereof, wherein the throughhole  272  is dimensioned for receiving a first end  312  of the first cross-shaft  310 . The second crank arm  276  has a throughhole  282  formed proximal to a second end  280  thereof, wherein the throughhole  282  is dimensioned for receiving a first end  322  of the second cross-shaft  320 . The third crank arm  286  has a throughhole  292  formed proximal to a second end  290  thereof, wherein the throughhole  292  is dimensioned for receiving a first mini-shaft  338 . The fourth crank arm  296  has a throughhole  302  formed proximal to a second end  300  thereof, wherein the throughhole  302  is dimensioned for receiving a second mini-shaft  348 . 
     A second end  314  of cross-shaft  310  is secured to the first gearbox  330  via coupling  332 . On the opposing side of the first gearbox  330  extends the first mini-shaft  338 . The rotational output of the motor  390  is attached to and in mechanical communication with the first gearbox  330  such that the first gearbox  330  reduces the rotational speed of the motor  390  output and transfers this reduced rotational speed to the first cross-shaft  310  and the first mini-shaft  338 . The first cross-shaft  310  and the first mini-shaft  338  rotate the first crank arm  266  and the third crank arm  286 , respectively. It should be noted that one skilled in the art, given the rotational output speed of the motor  390  and the desired rotational speed of the first crank arm  266  and the third crank arm  286 , would be able to select a gearbox having the desired rotational speed reduction. 
     The rotational output of the motor  390  is additionally attached to and in mechanical communication with the second gearbox  340  via the propeller shaft  360 , wherein a first end  362  of propeller shaft  360  is attached to the motor  390  output and a second end  364  of propeller shaft  360  is attached to the second gearbox  340 . The second gearbox  340  reduces the rotational speed of the motor  390  output and transfers this reduced rotational speed to the second cross-shaft  320  and the second mini-shaft  348 . The second cross-shaft  320  and the second mini-shaft  348  rotate the second crank arm  276  and the fourth crank arm  296 , respectively. It should be noted that one skilled in the art, given the rotational output speed of the motor  390  and the desired rotational speed of the second crank arm  276  and the fourth crank arm  296 , would be able to select a gearbox having the desired rotational speed reduction. 
     A first series of spit rests  370  is attached to and evenly spaced apart on the first longitudinal edge  226  of the first walking beam  220  via bolts or any other attaching means. Each spit rest  370  is shaped and dimensioned for receiving an end of one of the spits. A second series of spit rests  380  is attached to the first longitudinal edge  236  of the second walking beam  230  via bolts or any other attaching means. Each spit rest  380  is shaped and dimensioned for receiving the other end of one of the spits. 
     In use, when the motor  390  is powered, a rotational output is thereby generated, wherein said rotational output is mechanically transferred directly to the first gearbox  330  and indirectly to the second gearbox  340  via the propeller shaft  360 . First gearbox  330  and second gearbox  340  can reduce the rotational speed of the motor  390  to the speed desired for a particular application. The reduced rotational speed of the first gearbox  330  is transferred directly to the first cross-shaft  310  and the first mini-shaft  338 . The first cross-shaft  310  is rigidly attached to the first crank arm  266  and thus rotates the first crank arm  266 , wherein the first crank arm  266  is pivotably attached to the first walking-beam support  240 , and wherein the first walking-beam support  240  is attached to the first end  222  of the first walking beam  220 . As such, the first end  222  of the first walking beam  220  is rotated in a circular motion. The first mini-shaft  338  is rigidly attached to the third crank arm  286  thereby causing the third crank arm  286  to rotate which in turn rotates the pivotably attached third walking-beam support  252  and thus, the first end  232  of the second walking beam  230  in a circular motion. 
     The second ends  224  and  234  of the first walking beam  220  and the second walking beam  230 , respectively, are synchronously rotated with the first ends  222  and  232  of the first walking beam  220  and the second walking beam  230 , respectively, via the output of the second gearbox  340 . The reduced rotational speed of the second gearbox  340  is transferred directly to the second cross-shaft  320  and the second minishaft  348 . The second cross-shaft  320  is rigidly attached to the second crank arm  276  and thus rotates the second crank arm  276 , wherein the second crank arm  276  is pivotably attached to the second walking-beam support  246 , and wherein the second walking-beam support  246  is attached to the second end  224  of the first walking beam  220 . As such, the second end  224  of the first walking beam  220  is rotated in a circular motion. The second mini-shaft  348  is rigidly attached to the fourth crank arm  296  thereby causing the fourth crank arm  296  to rotate, which in turn rotates the pivotably attached fourth walking-beam support  258  and thus, the second end  234  of the second walking beam  230  in a circular motion. 
     Consequently, as walking beams  220  and  230  are rotated, the spit rests  370  and  380  lift the spits from a cooking position and advance them in a generally circular motion to the next cooking position. Walking beams  220  and  230  are continued in a generally circular motion and thus returned to their initial position wherein the spit rests  370  and  380  lift the spits and advance them to the next position. 
     First, second, and third alternate means for driving walking beams  220  and  230  are contemplated as shown in FIGS. 7-9, respectively. For instance, FIG. 7 shows a pneumatic means wherein a vertically positioned pneumatic piston  460  and a horizontally positioned pneumatic piston  450  are provided. The vertically positioned pneumatic piston  460  provides vertical movement while the horizontally positioned pneumatic piston  450  provides horizontal movement, wherein the pistons work together to create a generally circular movement pattern. In FIG. 8, a drive means is shown that utilizes spaced-apart sprockets  550  and  560  mechanically linked by a chain  570 ; other linking means such as, for exemplary purposes only, a cable or belt may be utilized. In FIG. 9, a first linking member  650  and a second (not shown) are utilized on each walking beam  220  and  230  to synchronize their movement. The linking member  650  is shown in a first position A and a second rotated position B. 
     While the invention has been shown in preferred forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention as set forth in the following claims.