referring now to the drawings in which like numerals indicate like elements throughout the several views , fig1 and 2 each depict one embodiment of an improved draft chimney 10 of the present invention within a convection based grill 12 . each convection based grill 12 includes a cabinet 14 with a plurality of surfaces for defining a cabinet interior 16 ( fig3 a and 3b ). the cabinet interior 16 is divided into two chambers by an insulating baffle 18 extending across the longitudinal dimension of the cabinet 14 . the two chambers include a heating chamber 20 and a cooking chamber 22 . in the lower portion of the heating chamber 20 is a heating element 24 and a steel flame grate 26 is positioned over the heating element 24 . a cooking surface 28 substantially extends the length and the width of the cooking chamber 22 . the grill 12 is described in greater detail in copending u . s . patent application having u . s . ser . no . 09 / 083 , 416 filed on may 22 , 1998 and titled “ a convection based cooking apparatus with improved airflow ”, and in copending u . s . patent application having u . s . ser . no . 09 / 329 , 690 filed on jun . 10 , 1999 and titled “ a convection based cooking apparatus with improved airflow ”, the entire disclosures of which are incorporated herein by reference . referring now to fig3 a , 3 b and 4 , the cabinet 14 is defined by a bottom surface 30 , a front surface 32 , a back surface 34 , a left side surface 36 , and a right side surface 38 . the combination of the bottom surface 30 with lower portions of the front surface 32 , the back surface 34 , the left side surface 36 and the right side surface 38 , defines a lower portion of the cabinet interior , and is commonly referred to as a lower container 40 . also , the cabinet 14 is further defined by a hood 42 , the interior of which is commonly referred to as an upper cabinet interior , best illustrated in fig5 . the hood 42 is defined by upper portions of the front surface 32 , the back surface 34 , the left side surface 36 , and the right side surface 38 . still referring to fig3 a and 3b , the chimney 10 is defined by the right side surface 38 , portions of the front and back side surfaces 32 , 34 , and an internal surface 50 positioned in substantially a vertical manner . in fig3 a , the internal surface 50 is parallel to the right side surface 38 . in another embodiment , as shown in fig3 b , a portion of the internal surface 50 is parallel to the right side surface 38 and an another portion of the internal surface 50 tapers away from the right side surface 38 . as best shown in fig1 and 2 , the internal surface 50 has an upper portion 52 and a lower portion 54 . the upper portion 52 is attached to the inside of the hood 42 and the lower portion 54 is attached to the inside of the lower container 40 . when the hood 42 is opened to expose the cabinet interior 16 as shown in fig1 and 2 , the draft chimney 10 is separated into two pieces . however , when the hood 42 is closed as shown in fig3 a and 3b , the upper and lower portions 52 , 54 are joined together to define the entire length of the draft chimney 10 . the length of the draft chimney is commonly refer to as a flue and is described in greater detail below . in order to insure the upper and lower portions 52 , 54 of the internal surface 50 are properly joined together each time they come into contact with each other , the ends of each portion are bent back in a widthwise manner to define flanges 56 and 58 . the end of the upper portion 52 of the internal surface is bent inward and the end of the lower portion 54 of the internal surface in bent outward toward the right side surface 38 to form a seal when the hood 42 is closed . fig4 also illustrates the inwardly bent flanges 56 , 58 of the internal surface 50 . the seal is formed by permitting the upper and lower portions 52 , 54 to overlap as shown in fig3 a . alternatively , as shown in fig3 b , the seal could be formed by permitting the flange 56 to directly abut the flange 58 without the upper and lower portions 52 , 54 overlapping . the draft chimney 10 includes an elongated , vertical flue 60 having a first opening 62 and a second opening 64 . the internal surface 50 defines a portion of the flue 60 . therefore , the flue 60 is separable into two portions as shown in fig1 and 2 . preferably , the flue 60 is prismatic and the length of the flue 60 in the direction of airflow is longer than the width of the flue ; however , alternative configurations are also anticipated by the present invention . the first opening 62 communicates with the cabinet interior 16 . preferably , the first opening 62 is defined between the bottom surface 30 and the end of the vertically positioned internal surface 50 as shown in fig1 and 2 . the width of the first opening 62 can extend only a portion of the width of the cabinet 14 as shown in fig1 or , alternatively , the width of the first opening 62 can extend the full width of the cabinet 14 as shown in fig2 . in operation , ambient air enters the heating chamber 20 through an air inlet 70 . the ambient air is heated and rises through the steel frame grate 26 towards the top of the heating chamber 20 . eventually , the heated air is forced through an air passage 72 over the baffle 18 into the cooking chamber 22 . as the heated air is forced into the cooking chamber 22 , the cooler air existing the cooking chamber 22 is forced down through the first opening 62 of the flue 60 . the heated air that is forced into the flue 60 of the draft chimney 10 rises to the top and exits through the second opening 64 in the top of the hood 42 to the environment surrounding the cabinet 14 . in the preferred embodiment , a plurality of smaller exit openings combined together to form the second opening 64 as shown in fig5 . the portion of the surface with the smaller exit openings is commonly referred to as being grilled . a path of convection airflow , generally shown by arrows 80 a , 80 b and 80 c in fig3 a and 3b is created within the cabinet 14 during operation of the grill 12 . the portion 80 a of the path begins at the air inlet 70 and proceeds to the passage 72 over the baffle 18 as described above . then , the path continues through the cooking chamber 22 to pass over the cooking surface 28 in an even manner . this portion of the path is shown by the reference numeral 80 b . next , the path continues to the first opening 62 of the flue 60 of the draft chimney 10 . the portion 80 c begins at the first opening 62 , rises to the second opening 64 , and passes into the exterior environment surrounding the grill 12 . preferably , the draft chimney 10 is entirely defined within the cabinet 14 such that the end of the path 70 communicates with the exterior of the cabinet as best shown in fig1 - 3a and 3 b . alternatively , the flue 60 may extend beyond the top of the hood 42 so that a portion of the path of airflow extends beyond the cabinet 16 before exiting to the environment surrounding the grill . the present invention has been illustrated in relation to particular embodiments which are intended in all respects to be illustrative rather than restrictive . those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention . accordingly , the scope of the present invention is described by the claims appended hereto and supported by the foregoing .
a draft chimney for a convention based apparatus . the draft chimney comprises a flue at least partially defining a path of convection airflow through at least a portion of the interior of a cabinet . the flue passes convection airflow to the exterior of the cabinet .