Patent Publication Number: US-2017370592-A1

Title: Chimney Vent Cap

Description:
FIELD OF THE INVENTION 
     The present invention relates, generally, to the field of devices having chimneys through which exhaust gases exit and, more particularly, to apparatuses and methods for controlling the flow of exhaust gases exiting grills, cookers, smokers, and other devices for food preparation. 
     BACKGROUND OF THE INVENTION 
     The temperature within grills, cookers, smokers, and other devices used to prepare food is often controlled by adjustment of the amount of air flowing into the grill, cooker, smoker, or other device in relation to the amount of fuel available for combustion. Traditionally, grills, cookers, smokers, or other devices have permitted such adjustment via air inlet openings configured with user-adjustable dampers. Some grills, cookers, smokers, and other devices have also permitted such adjustment via exhaust outlet openings that are similarly configured with user-adjustable dampers. Through user adjustment of the air inlet dampers and exhaust outlet dampers, alone or in combination, more or less air is permitted to enter and more or less exhaust gases are permitted to exit with the result being that the fuel combustion rate and, hence, the temperature within the grill, cooker, smoker, or other device is increased or decreased as desired by the user. 
     In some grills, cookers, and smokers, such as Kamado-style cookers, air generally enters through an air inlet opening having a user-adjustable damper that is located near the device&#39;s lowermost portion or base. After entering, the air oxidizes fuel present in a combustion zone, causing hot exhaust gases to be produced. The hot exhaust gases pass upward through the grill, cooker, smoker, or other device and transfer a portion of their heat to the food being prepared and/or to the walls and other components of the device. The hot exhaust gases continue to pass upward and through a vent stack or chimney, located at or near the highest location of the device&#39;s uppermost portion or lid, before exiting the device into the surrounding environment. 
     Many Kamado-style cookers are fitted with a daisy wheel damper atop the vent stack or chimney to permit users to control the flow of exhaust gases attempting to exit via the vent stack or chimney. Unfortunately, some daisy wheel dampers require users to place their hands within the hot exhaust gas stream exiting the cooker in order to adjust the dampers, thereby exposing the users to the possibility of burns from exposure to hot exhaust gases. Other daisy wheel dampers may change position when cooker lids are opened or closed, requiring users to reset the dampers&#39; positions in order to obtain a desired flow of hot exhaust gases through the cookers and desired temperatures within the cookers. Still other daisy wheel dampers are leaky and may allow rain water or other liquid to enter a cooker, even if configured in a “closed” position in anticipation of possible rainfall or exposure to liquids. 
     There is, therefore, a need in the industry for a user-adjustable device for controlling the exit of exhaust gases from (and, hence, the draft through) a grill, cooker, smoker, or other device that solves these and other problems, deficiencies, and shortcomings of present devices. 
     SUMMARY OF THE INVENTION 
     Broadly described, the present invention comprises apparatuses and methods for controlling the flow of exhaust gases exiting a vent stack or chimney of a grill, cooker, smoker, or other device. In one inventive aspect and according to an example embodiment, a chimney vent cap is adapted to maintain its configuration when a lid or top of the grill, cooker, smoker, or other device is opened, closed, or moved into another position such that the flow of exhaust gases exiting a vent stack or chimney to which the chimney vent cap is secured remains substantially the same as before the lid or top was opened, closed, or moved into another position. In another inventive aspect and according to an example embodiment, the chimney vent cap is configurable in a plurality of configurations to adjust the flow of exhaust gases exiting a vent stack or chimney to which the chimney vent cap is secured and to do so without a user inserting the user&#39;s hand or fingers into the flow of exhaust gases. In still another inventive aspect and according to an example embodiment, the chimney vent cap is operable in a single plane to control or adjust the flow of exhaust gases exiting a grill, cooker, smoker, or other device. In yet another inventive aspect and according to an example embodiment, the chimney vent cap is operable to control or adjust the flow of exhaust gases exiting a grill, cooker, smoker, or other device without substantially redirecting the flow of exhaust gases from a predominant direction of travel prior to encountering the chimney vent cap. In yet another inventive aspect and according to an example embodiment, the chimney vent cap is configured to direct liquid (such as, but not limited to, rain water) away from a vent stack or chimney of a grill, cooker, smoker, or other device with which the chimney vent cap is used and substantially prevent such liquid from entering the vent stack or chimney. 
     Other inventive aspects, advantages and benefits of the present invention may become apparent upon reading and understanding the present specification when taken in conjunction with the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  displays a perspective view of a chimney vent cap, in accordance with a first example embodiment of the present invention, in use atop a cooking device and configured in a fully-closed, first configuration. 
         FIG. 2  displays a perspective view of the chimney vent cap of  FIG. 1  in use atop the cooking device and configured in a fully-open, second configuration. 
         FIG. 3  displays a perspective view of the chimney vent cap of  FIG. 1  in use atop the cooking device and configured in an intermediate, partially-open, third configuration. 
         FIG. 4  displays a perspective view of the chimney vent cap of  FIG. 1  in the fully-closed, first configuration. 
         FIG. 5  displays a front elevation view of the chimney vent cap of  FIG. 4 . 
         FIG. 6  displays a back elevation view of the chimney vent cap of  FIG. 4 . 
         FIG. 7  displays a right side elevation view of the chimney vent cap of  FIG. 4 . 
         FIG. 8  displays a left side elevation view of the chimney vent cap of  FIG. 4 . 
         FIG. 9  displays a top plan view of the chimney vent cap of  FIG. 4 . 
         FIG. 10  displays a bottom plan view of the chimney vent cap of  FIG. 4 . 
         FIG. 11  displays an exploded view of the chimney vent cap of  FIG. 4 . 
         FIG. 12  displays a perspective view of a control member of the chimney vent cap of  FIG. 1 . 
         FIG. 13  displays a front elevation view of the control member of  FIG. 12 . 
         FIG. 14  displays a back elevation view of the control member of  FIG. 12 . 
         FIG. 15  displays a right side elevation view of the control member of  FIG. 12 . 
         FIG. 16  displays a left side elevation view of the control member of  FIG. 12 . 
         FIG. 17  displays a top plan view of the control member of  FIG. 12 . 
         FIG. 18  displays a bottom plan view of the control member of  FIG. 12 . 
         FIG. 19  displays a perspective view of a base member of the chimney vent cap of  FIG. 1 . 
         FIG. 20  displays a front elevation view of the base member of  FIG. 19 . 
         FIG. 21  displays a back elevation view of the base member of  FIG. 19 . 
         FIG. 22  displays a right side elevation view of the base member of  FIG. 19 . 
         FIG. 23  displays a left side elevation view of the base member of  FIG. 19 . 
         FIG. 24  displays a top plan view of the base member of  FIG. 19 . 
         FIG. 25  displays a bottom plan view of the base member of  FIG. 19 . 
         FIG. 26  displays a perspective view of a grip member of the chimney vent cap of  FIG. 1 . 
         FIG. 27  displays a front elevation view of the grip member of  FIG. 26 . 
         FIG. 28  displays a back elevation view of the grip member of  FIG. 26 . 
         FIG. 29  displays a right side elevation view of the grip member of  FIG. 26 . 
         FIG. 30  displays a left side elevation view of the grip member of  FIG. 26 . 
         FIG. 31  displays a top plan view of the grip member of the grip member of  FIG. 26 . 
         FIG. 32  displays a bottom plan view of the grip member of  FIG. 26 . 
         FIG. 33  displays a front elevation view of the chimney vent cap of  FIG. 1  in use atop the cooking device and configured in the fully-closed, first configuration. 
         FIG. 34  displays a top plan view of the chimney vent cap of  FIG. 33 . 
         FIG. 35  displays a bottom plan view of the chimney vent cap of  FIG. 33 . 
         FIG. 36  displays a front elevation view of the chimney vent cap of  FIG. 2  in use atop the cooking device and configured in the fully-open, second configuration. 
         FIG. 37  displays a top plan view of the chimney vent cap of  FIG. 36 . 
         FIG. 38  displays a bottom plan view of the chimney vent cap of  FIG. 36 . 
         FIG. 39  displays a front elevation view of the chimney vent cap of  FIG. 3  in use atop the cooking device and configured in the intermediate, partially-open, third configuration. 
         FIG. 40  displays a top plan view of the chimney vent cap of  FIG. 36 . 
         FIG. 41  displays a bottom plan view of the chimney vent cap of  FIG. 36 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings in which like numerals represent similar elements or steps throughout the several views,  FIG. 1  displays a perspective view of a chimney vent cap  100  in accordance with an example embodiment of the present invention. The chimney vent cap  100  is, as illustrated in  FIG. 1 , adapted to reside atop and about a chimney of a grill, cooker (such as, but not limited to, a Kamado-style cooker shown in broken lines in  FIG. 1 ), smoker, or other device having a chimney (such as, but not limited to, a chiminea) and to receive at least a portion of the chimney therein. When so positioned or oriented relative to a chimney, exhaust gases flowing through the chimney (including, without limitation, by-product gases from the combustion of fuel occurring within or in connection with the grill, cooker, smoker or other device and other entrained gases not resulting from the combustion of fuel) are directed to the chimney vent cap  100  which, based on its then current user-selectable configuration, (a) maximally, or entirely, blocks the flow of exhaust gases attempting to pass through and exit the chimney and chimney vent cap  100 , (b) minimally blocks the flow of exhaust gases attempting to pass through and exit the chimney and chimney vent cap  100 , or (c) partially blocks the flow of exhaust gases attempting to pass through and exit the chimney and chimney vent cap  100 . By increasingly or decreasingly blocking the flow of the exhaust gases, the chimney vent cap  100  respectively creates more or less backpressure within the grill, cooker, smoker, chiminea, or other device (each being sometimes referred to herein, individually, with the term “cooking device”) and correspondingly decreases or increases the draft through and the flow of fresh air into the cooking device via an air inlet located elsewhere in the cooking device. By decreasing the amount of fresh air entering and available for combustion, the temperature within the cooking device is decreased. Conversely, by increasing the amount of fresh air entering and available for combustion, the temperature within the cooking device is increased. Thus, by controlling the flow of exhaust gases attempting to pass through and exit the chimney and chimney vent cap  100 , the chimney vent cap  100  at least partially controls the temperature within the cooking device. 
     The chimney vent cap  100 , in accordance with a first example embodiment, comprises a base member  102 , a control member  104 , and a grip member  106 . The base member  102  and control member  104  are pivotally connected for rotation therebetween to enable the control member  104  to be pivotally configured relative to the base member  102 , as desired by a user, to cause the chimney vent cap  100  to minimally, maximally, or partially block and control the flow of the exhaust gases attempting to pass through and exit the chimney vent cap  100 , and to at least partially control the temperature inside the cooking device with which the chimney vent cap  100  is used. The grip member  106  is connected to the control member  104  and may be grasped by a user to impart a force to the grip member  106  and control member  104  (by virtue of the grip members&#39; connection to control member  104 ) causing the control member  104  to pivot relative to the base member  102  and place the chimney vent cap  100  in a fully-closed, first configuration (see  FIG. 1 ), in a fully-open, second configuration (see  FIG. 2 ), or in one of a plurality of intermediate, partially-open, third configurations (see  FIG. 3 ) in which the control member  104  is positioned at an angular location between the control member&#39;s angular location in the fully-closed, first configuration and the fully-open, second configuration. In the fully-closed, first configuration, the chimney vent cap  100  maximally (or entirely) blocks the flow of exhaust gases and prevents the entire flow of exhaust gases from passing through and exiting the chimney vent cap  100  into the surrounding environment. In the fully-open, second configuration, the chimney vent cap  100  minimally blocks the flow of exhaust gases and allows a maximum flow of the exhaust gases to pass through and exit the chimney vent cap  100  into the surrounding environment. In the intermediate, partially-open, third configuration, the chimney vent cap  100  partially blocks the flow of exhaust gases and allows part of the flow of exhaust gases to pass through and exit the chimney vent cap  100  into the surrounding environment. 
     The chimney vent cap  100  is illustrated more clearly in the fully-closed, first configuration in the perspective and orthogonal views of  FIGS. 4-10  and in the exploded view of  FIG. 11 . As seen in the top and bottom plan views, the base and control members  102 ,  104  each have a generally circular, plan view shape with the grip member  106  extending outside the base and control members&#39; circular peripheries. The base member  102  defines a central longitudinal axis  108  extending therethrough such that when the chimney vent cap  100  is installed atop and about the chimney of a cooking device, the central longitudinal axis  108  is generally collinear with a central longitudinal axis of the chimney. The control member  104  sits on top of and in contact with the base member  102  and, together, the control member  104  and base member  102  define a rotational axis  110  extending generally parallel to and offset laterally and eccentrically from central longitudinal axis  108 . The control member  104  is eccentrically rotatable about rotational axis  110  relative to the base member  102  to permit the control member  104  and base member  102  to be moved between and configured in their relative positions in the fully-closed, first configuration, in the fully-open, second configuration, or in an intermediate, partially-open, third configuration. 
     The control member  104  and base member  102  (and, more particularly, the disc portion&#39;s planar bottom surface  126  and base member&#39;s planar bearing surface  182 ) also define a plane  112  extending laterally therebetween that is substantially perpendicular to the central longitudinal axis  108  and rotational axis  110  and through which all exhaust gases must pass when exiting the chimney vent cap  100  into the surrounding environment. During rotation of the control member  104  about rotational axis  110 , the control member  104  slides on, in contact with, and relative to base member  102  such that the disc portion&#39;s planar bottom surface  126  moves in a single plane parallel to plane  112  and the base member&#39;s planar bearing surface  182 . And, for that matter, all other portions of the control member  104  also correspondingly move in a respective plane parallel to plane  112  and, hence, parallel to respective portions of the base member  102 . At least because the bottom surface  126  of the control member  104  (and, more particularly, the bottom surface  126  of disc portion  114 ) moves within a single plane, the chimney vent cap  100  controls the flow of exhaust gases via movement in a single plane and with such single plane being substantially perpendicular to the predominant direction of flow of the exhaust gases. Advantageously, through use of such planar control, the chimney vent cap  100  controls the flow of exhaust gases from a cooking device without requiring the exhaust gases to substantially change their predominant direction of flow as occurs in other cooking device exhaust gas flow control devices. By requiring no substantial change in the predominant direction of flow, the unwanted influence on draft and temperature within a cooking device created by backpressure resulting from a change in the predominant direction of exhaust gas flow is avoided, thereby allowing the chimney vent cap  100  to provide more accurate and true control over draft and temperature within the cooking device as compared with exhaust gas flow control devices that cause a substantial change in the predominant direction of flow of exhaust gases. 
     The control member  104 , seen isolated in the various views of  FIGS. 12-18 , includes a disc portion  114  that defines a central longitudinal axis  116  extending through the plan view center of the disc portion  114  which is substantially parallel to the base member&#39;s central longitudinal axis  108  and to rotational axis  110 . When the chimney vent cap  100  is configured in the fully-closed, first configuration, the disc portion&#39;s central longitudinal axis  116  is collinear with the base member&#39;s central longitudinal axis  108 . When the chimney vent cap  100  is configured in the fully-open, second configuration or in any intermediate, partially-open, third configuration, the disc portion&#39;s central longitudinal axis  116  remains parallel to the base member&#39;s central longitudinal axis  108  by virtue of the control member  104  moving only parallel to plane  112 , but the disc portion&#39;s central longitudinal axis  116  is not collinear with the base member&#39;s central longitudinal axis  108 . Instead, the disc portion&#39;s central longitudinal axis  116  is located at a respective position along an arc  118  (see  FIG. 10 ) extending at a radius about rotational axis  110 , resulting from rotation of the control member  104  relative to the base member  102  about rotational axis  110  and into the respective fully-open, second configuration or an intermediate, partially-open, third configuration. 
     The disc portion  114  of the control member  104  has an edge  120  at its periphery and a top surface  122  bounded by edge  120  that is highest in elevation near central longitudinal axis  116  and slopes gradually away from central longitudinal axis  116  and toward edge  120 . The disc portion  114  is sized relative to the base member  102  such that the disc portion  114  fully occludes a second opening  170  (described below) of the base member  102  when the chimney vent cap  100  is configured in the fully-closed, first configuration. By fully occluding the second opening  170 , the disc portion  114  fully blocks exhaust gases from passing through and exiting the chimney vent cap  100  and fully blocks rain or other liquid from entering the chimney vent cap  100  (and, hence, from entering a cooking device with which the chimney vent cap  100  is used) when the chimney vent cap  100  is configured in the fully-closed, first configuration. 
     The disc portion  114  is also sized relative to the base member  102  so that edge  120  and a circular groove  124  formed slightly inboard of edge  120  in the disc portion&#39;s generally planar bottom surface  126  (also sometimes referred to herein as the “control member&#39;s bottom surface  126 ”), both extend at least partially over a rain directing portion  202  (described below) of the base member&#39;s end wall  166  when the chimney vent cap  100  is configured in the fully-closed, first configuration (see  FIGS. 4-8 ). Because the disc portion&#39;s top surface  122  slopes generally toward edge  120  and because edge  120  and groove  124  extend over the rain directing portion  202  of the base member&#39;s end wall  166  in such configuration, rain water or other liquid falling on or striking the control member  104  is directed to the disc portion&#39;s edge  120  and, typically, falls or drips from the edge  120  or groove  124  (the edge  120  and groove  124  together comprising a “drip edge”) onto the rain directing portion  202  of the base member&#39;s end wall  166 . The rain water or other liquid is then guided away from the base member&#39;s second opening  170  by the rain directing portion  202 , thereby minimizing the possibility that rain water or other liquid falling on or striking the control member  104  may enter the chimney vent cap  100  and cooking device with which the chimney vent cap  100  is in use. 
     The control member  104  also includes a rib  128  that protrudes from the disc portion&#39;s top surface  122  and to which the grip member  106  connects. The rib  128  has a first end  130  located slightly inboard of the disc portion&#39;s edge  120  and extends substantially across the disc portion&#39;s top surface  122  in a generally diametric direction through the disc portion&#39;s plan view center to a distal second end  132  located slightly beyond or outboard of the disc portion&#39;s edge  120 . The rib  128  has a first portion  134  that extends from the rib&#39;s first end  130  to a shoulder surface  136  located generally near the disc portion&#39;s edge  120 , and has a second portion  138  that protrudes from the shoulder surface  136  to the rib&#39;s second end  132  and over which the grip member  106  resides as more fully described below. The shoulder surface  136  defines an angle,  0 , with a vertical axis. Because the rib&#39;s second end  132  is slightly beyond and outboard of the disc portion&#39;s edge  120 , a major portion of the grip member  106  is also positioned slightly outboard of the disc portion&#39;s edge  120 . By virtue of the major portion of the grip member  106  being located slightly outboard of the disc portion&#39;s edge  120  and the eccentric rotation of the control member  104  (and, hence, the eccentric rotation of the grip member  106 ) about rotational axis  110  during movement of the control member  104  relative to the base member  102 , a user&#39;s fingers will generally always be outside the disc portion&#39;s periphery and outside the base member&#39;s periphery when grasping the grip member  106  to rotate the control member  104  relative to the base member  102  (see  FIGS. 4-6 and 9-11 ), thereby minimizing exposure of the user&#39;s fingers to hot exhaust gases exiting the base member&#39;s second opening  170  and making the chimney vent cap  100  safer to use. 
     The rib&#39;s first portion  134  has a generally triangular shape when viewed in the front and back views of  FIGS. 13 and 14 , has a generally rounded rectangular cross sectional shape at each longitudinal location between the rib&#39;s first end  130  and shoulder surface  136 , and is contoured to rise from and blend with the disc portion&#39;s top surface  122  at each such longitudinal location while gradually increasing in height relative to the disc portion&#39;s top surface  122  from a minimum height at the rib&#39;s first end  130  to a maximum height near the shoulder surface  136 . The rib&#39;s second portion  138  extends from the shoulder surface  136  to the rib&#39;s second end  132  with the cross section of the rib  128  abruptly changing at the shoulder surface  136  to a rectangular cross sectional shape at each longitudinal location between the shoulder surface  136  and the rib&#39;s second end  132  for which the cross sectional dimensions of the rib  128  are smaller in each direction than the similarly disposed cross sectional dimensions of the rib&#39;s first portion  134  at or near the shoulder surface  136 . The cross sectional shape and dimensions of the rib&#39;s second portion  138  are selected for mating cooperation with the grip member&#39;s cavity  230  (described below) to enable the grip member  106  to be slid, during assembly, onto the rib&#39;s second portion  138  (and, correspondingly, for the rib&#39;s second portion  138  to be inserted into and received by and within the grip member&#39;s cavity  230 ) and into abutment with the rib&#39;s first portion  134  at the shoulder surface  136  as displayed in  FIGS. 4-6, 9, and 11 . The rib&#39;s second portion  138  has an arcuate shape near the rib&#39;s second end  132  as seen in the front and back views of  FIGS. 13 and 14 . The arcuate shape renders easier the initial installation of the grip member  106  onto and about the rib&#39;s second portion  138  (via insertion of the rib&#39;s second portion  138  into the grip member&#39;s cavity  230 ) during assembly of the chimney vent cap  100 . The cross sectional shapes and dimensions of the rib&#39;s second portion  138  and grip member&#39;s cavity  230  are also selected such that a friction fit is created between the rib&#39;s second portion  138  and the grip member  106 , thereby causing the grip member  106  to remain affixed to the rib&#39;s second portion  138 . 
     The control member  104  defines a bore  140  that receives a fastener  142  at a location near the rib&#39;s first end  130  that pivotally secures the control member  104  to the base member  102  with the control member&#39;s bottom surface  126  in contact with and parallel to the base member&#39;s bearing surface  182  and plane  112 . The fastener  142  is also received within a corresponding hole  196  defined in the base member  102  such that rotational axis  110  extends through bore  140 , fastener  142  and hole  196  (see  FIG. 10 ). The hole  192  is sized relative to the fastener  142  such that the fastener  142  does not rotate relative to the control member  104  during movement of the control member  104 , but freely rotates within hole  196  and relative to base member  102  acting as a pivot pin to enable pivoting of the control member  104  relative to the base member  102 . As a consequence, the control member  104  slidably rotates relative to the base member  102  about longitudinal axis  110  and with the control member&#39;s bottom surface  126  in contact with and parallel to the base member&#39;s bearing surface  182  and plane  112  when a force, “F 1 ” or “F 2 ”, is applied to grip member  106  by a user in a direction generally tangential to the control member&#39;s disc portion  114  (see  FIG. 9 ) and tending to rotate and re-position the control member  104  relative to the base member  102  into a different position corresponding to a different configuration of the chimney vent cap  100 . According to the first example embodiment, the fastener  142  comprises a socket cap screw, but it should be understood and appreciated that the fastener  142  may comprise other forms or types of fasteners in other example embodiments. 
     Additionally, the control member  104  further comprises a stop  144  that depends from the control member&#39;s disc portion  114  at a location generally near the rib&#39;s first end  130  and bore  140 , but angularly offset about central longitudinal axis  116  from bore  140  and with a radius, R STOP , extending between stop  144  and central longitudinal axis  116  having a shorter measure than a radius, R BORE , extending between bore  140  and central longitudinal axis  116 . As seen in the bottom plan view of  FIG. 18  and as described in more detail below, the base member  102  has a side wall  164  that defines a first opening  168  of the base member  102  for receiving at least a portion of a chimney of a cooking device therein. The base member  102  also has an end wall  166  with a slightly protruding support portion  180  that defines a second opening  170  of the base member  102  through which exhaust gases pass while exiting the chimney vent cap  100 . The stop  144  protrudes into the second opening  170  of the base member  102  and limits rotational movement of the control member  104  relative to the base member  102  about rotational axis  110  and in both the clockwise and counterclockwise angular directions. 
     The base member  102 , as briefly described above and shown in isolation in  FIGS. 19-25 , has a first end  160  and a distal second end  162  through which the base member&#39;s central longitudinal axis  108  extends. A side wall  164  of the base member  102  extends radially about and in the direction of the base member&#39;s central longitudinal axis  108  from the first end  160  toward an end wall  166  of the base member  102  at second end  162 . The side wall  164  defines a first opening  168  of the base member  102  at the base member&#39;s first end  160  for receiving at least part of the chimney of a cooking device therethrough. The end wall  166  defines a second opening  170  of the base member  102  at the base member&#39;s second end  162  through which exhaust gases pass while exiting the chimney vent cap  100 . Together, the side and end walls  164 ,  166  form a one piece, unitary structure and define a cavity  172  within the base member  102  such that the base member&#39;s first and second openings  168 ,  170  are in fluid communication via cavity  172 , which extends between the first and second openings  168 ,  170 . The side and end walls  164 ,  166  are configured such that the cavity  172  is sized to snugly receive at least part of the chimney of a cooking device therein with the chimney&#39;s side wall being substantially parallel to the base member&#39;s side wall  164 , with the chimney&#39;s end abutting the inner surface of the base member&#39;s end wall  166  near the base member&#39;s second end  162 , and preferably with the free end of the side wall  164  resting on the cooking device and about the cooking device&#39;s chimney at the base member&#39;s first end  160 . According to the example embodiment, the side and end walls  164 ,  166  are manufactured from cast iron, but may be made, in other example embodiments, from other materials and/or using other manufacturing methods appropriate to provide a base member  102  having similar physical and mechanical characteristics. Also according to the example embodiment, the first opening  168  comprises a circular opening extending radially about central longitudinal axis  108 . 
     The side wall  164  has an outside surface  174  and has outside radius, R 1 , at the base member&#39;s first end  160  that is larger than the side wall&#39;s outside radius, R 2 , at the location where the side wall  164  meets the end wall  166  (see  FIG. 25 ). Consequentially, the side wall  164  defines an angle, α, with the base member&#39;s central longitudinal axis  108 . By virtue of the side wall  164  forming such angle, rain water or other liquid striking the side wall&#39;s outside surface  174  or running or dripping onto the side wall&#39;s outside surface  174  from other parts of the base member  102  is directed away from the base member&#39;s end wall  166  and away from the cooking device&#39;s chimney and any gap that might exist between the side wall  164  and such chimney at the base member&#39;s first end  160 . By directing rain water and other liquids in this manner, the possibility of rain water and other liquids entering the cooking device&#39;s chimney is reduced substantially. 
     The base member&#39;s end wall  166  has a support portion  180  that supports the control member  104  in the various configurations of the chimney vent cap  100  and during movement of the control member  104  relative to the base member  102 . The support portion  180  is formed as a boss that slightly protrudes in the direction of and about central longitudinal axis  108  and extends to the base member&#39;s second end  162 . At the base member&#39;s second end  162 , the support portion  180  defines the base member&#39;s second opening  170  and a bearing surface  182  that defines plane  184  substantially perpendicular to central longitudinal axis  108 . The bearing surface  182  is in contact with the control member&#39;s bottom surface  126  and supports the control member  104  atop the base member  102  before, during, and after sliding rotational movement of the control member  104  relative to the base member  102 . 
     The support portion  180  has a first edge  186  that extends radially about central longitudinal axis  108  and that defines the outer extents of the support portion  180  and the bearing surface  182 . The support portion  180  also has a second edge  188  that defines the perimeter of the base member&#39;s second opening  170 . Together, the edges  186 ,  188  define the inner and outer extents of the bearing surface  182  such that the bearing surface  182  extends between the first edge  186  and the second edge  188 . As best seen in  FIG. 24 , the width, “w”, of the bearing surface  182  measured in the radial direction about central longitudinal axis  108  between edges  186 ,  188  is different at various angular locations about central longitudinal axis  108 . As a consequence, the base member&#39;s second opening  170  is not circular and is not centered or symmetrical about central longitudinal axis  108 . However, the second opening  170  is sized and shaped to permit an appropriate flow of exhaust gases therethrough during use of the chimney vent cap  100  in its fully-open, second configuration that is sufficient to enable the cooking device with which the chimney vent cap  100  is in use to obtain a desired maximum internal temperature. 
     The base member  102 , as briefly described above, defines a hole  196  that receives fastener  142  to pivotally couple the control member  104  and base member  102 . More particularly, the support portion  180  of the base member&#39;s end wall  166  defines hole  196  with an opening in bearing surface  182  through which fastener  142  is inserted during assembly of the chimney vent cap  100 . After such assembly, the hole  196  and fastener  142  are coaxially aligned with rotational axis  110 . As illustrated more clearly in  FIGS. 24 and 25 , the hole  196  and rotational axis  110  are eccentrically located relative to the base member&#39;s central longitudinal axis  108  such that the control member  104  eccentrically rotates or pivots about rotational axis  110  and the bottom surface  126  of the control member&#39;s disc portion  114  moves parallel to planes  112 ,  184  and the base member&#39;s bearing surface  182 . 
     To maintain the relative positions of the base member  102  and control member  104  before, during and after rotation of the control member  104  relative to the base member  102  and in accordance with the first example embodiment, the base member  102  includes a magnet  200  exerting a sufficient magnetic force that is embedded in the support portion  180  of the base member&#39;s end wall  166 . The magnet  200  is embedded beneath the base member&#39;s bearing surface  182  and within the support portion  180 . The location for magnet  200  is selected, together with (a) the shape of the bearing surface  182  and second opening  170 , (b) the relative location of hole  196 , and (c) the relative location of stop  144  and the arc  254  traveled by the stop  144  (see  FIGS. 35, 38 and 41 ), to provide an arrangement of the relative positions of the magnet  200 , hole  196 , and stop  144  such that at any time and regardless of the configuration of the chimney vent cap  100  and, hence, of the control member  104  relative to the base member  102 , part of the control member&#39;s disc portion  114  is always located above the magnet  200  with the disc portion&#39;s lower surface  126  in close proximity to magnet  200 . Because the magnetic force exerted by the magnet  200  tends to attract the control member&#39;s disc portion  114  and because part of the control member&#39;s disc portion  114  is always above the magnet  200  due to the arrangement and positions of the magnet  200 , hole  196 , stop  144 , and arc  254 , the base member  102  and control member  104  are maintained in their then current positions and configuration unless or until a force, “F 1 ” or “F 2 ”, sufficient to temporarily overcome the magnetic force is applied to the grip member  106  causing rotation of the control member  104  about rotational axis  110  into a different configuration. Once in the different configuration, the magnetic force maintains the relative positions of the base and control members  102 ,  104  in such configuration, even during movement of the cooking device&#39;s chimney when a user opens or closes the cooking device&#39;s lid and, thereby, causes the flow of exhaust gases exiting the chimney vent cap  100  and the temperature within the cooking device to generally return to their states existing prior to opening of the cooking device&#39;s lid. 
     The base member&#39;s end wall  166  also has, as illustrated in  FIGS. 19-25 , a rain directing portion  202  extending between the base member&#39;s support portion  180  and side wall  164 . The rain directing portion  202  has an outside surface  204  that defines an angle, ( 3 , relative to the base member&#39;s central longitudinal axis  108 . Due to such angle, rain water and other liquids that drip onto the outside surface  204  from the control member  104  or that strike the outside surface  204  are directed away from the support portion  180  and toward the side wall  164 . By directing rain water and other liquids away from the support portion  180 , the rain directing portion  202  aids in substantially reducing the amount of rain water or other liquids that might enter the chimney vent cap  100  via the base member&#39;s second opening  170  and, hence, that might enter the chimney of the cooking device with which the chimney vent cap  100  is in use. 
     As briefly described above, the grip member  106  is connected to the control member  104  and is used by a user to configure the chimney vent cap  100  into a different configuration by rotating the control member  104  atop the base member  102  about rotational axis  110 . The grip member  106 , as seen in isolation and according to the first example embodiment in  FIGS. 26-32 , comprises a unitary structure adapted for secure grasping by a user&#39;s fingers. In order to minimize the risk of burns to the user&#39;s fingers, the grip member  106  is manufactured from a material that can withstand the temperatures reached by the cooking device with which the chimney vent cap  100  is used and that does not conduct heat well. According to the first example embodiment, the grip member  106  is manufactured from a silicone material. It should be understood and appreciated, however, that the grip member  106  may be manufactured from other materials in other example embodiments. 
     The grip member  106  is configured to allow a user to grasp and interact with the grip member  106  without slippage of the user&#39;s fingers. The grip member  106  comprises an elongate body  210  having a first end  212  and a second end  214  distal from the first end  212 . A central longitudinal axis  216  extends between and through the first and second ends  212 ,  214 . The elongate body  210  also has a front  218 , back  220 , top  222 , and bottom  224 . At the first end  212 , the body  210  has a substantially planar, end surface  226  that defines an angle, φ, with a vertical axis  228  as seen in  FIG. 27 . The angular measure of angle, φ, is selected to have the same angular measure as angle, 0, defined by the shoulder surface  136  of rib  128  such that the grip member&#39;s end surface  226  abuts shoulder surface  136  absent any gap therebetween when the grip member  106  is connected to the control member  104  during assembly of the chimney vent cap  100 . 
     The grip member&#39;s body  210  defines an elongate cavity  230  within the grip member  106  starting at the grip member&#39;s first end  212  and extending in the direction of central longitudinal axis  216  to a location substantially near grip member&#39;s second end  214 . The grip member&#39;s body  210  also defines an opening  232  in the end surface  226  that is in fluid communication with the elongate cavity  230 . The opening  232  and elongate cavity  230  are configured to cooperatively and snugly receive the second portion  138  and second end  132  of the control member&#39;s rib  128  therein. As such, the opening  232  and elongate cavity  230  generally have rectangular cross sections and are sized to receive the rib&#39;s second portion  138  and second end  132  without slippage between the body  210  and the rib&#39;s second portion  138  after the grip member  106  is fitted onto the rib&#39;s second portion  138 . 
     Additionally, the grip member&#39;s body  210  has a plurality of ridges  234  and a plurality of troughs  236  extending from the grip member&#39;s first end  212 , across the grip member&#39;s front  218 , around the grip member&#39;s second end  214 , and across the grip member&#39;s back  220 . The ridges  234  and troughs  236  are arranged in an alternating arrangement with successive ridges  234  in the vertical direction having a trough  236  therebetween. When the grip member  106  is grasped by a user to apply a force, “F 1 ” or “F 2 ”, to the grip member  106  tending to cause rotation of the control member  104  about rotational axis  110 , the skin on the user&#39;s fingers tends to conform to the shape of the ridges  234  and troughs  236  with some of the skin at least partially filling in one or more of the troughs  236 . By arranging the ridges  234  and troughs  236  in this manner and by virtue of such conformance of a user&#39;s skin to the shape of the ridges  234  and troughs  236 , slippage between the users&#39; grasping fingers and the grip member  106  is reduced significantly. 
     In use according to a method of operation and as illustrated in  FIGS. 1-3 and 33-41  in connection with a Kamado-style cooking device (shown in dashed lines), the chimney vent cap  100  is mounted atop the cooking device&#39;s chimney after insertion of the chimney through the base member&#39;s first opening  168 . In such position, the cavity  172  formed by the side and end walls  164 ,  166  of the base member  102  receives the chimney substantially therein with the chimney&#39;s side wall generally adjacent the base member&#39;s side wall  164  and the base member&#39;s first end  160  resting on the cooking device&#39;s lid, the chimney&#39;s end generally abutting the base member&#39;s end wall  166 , and at least a portion of the chimney&#39;s upper opening generally adjacent to the base member&#39;s second opening  170 . Also, the base member&#39;s central longitudinal axis  108  is collinear with the chimney&#39;s central longitudinal axis  250 . 
     The chimney vent cap  100  is, typically, mounted atop the cooking device&#39;s chimney with the chimney vent cap  100  initially configured in the fully-closed, first configuration as displayed in  FIGS. 1 and 33-35 . The chimney vent cap  100  is configured by a user in the fully-closed, first configuration when the cooking device is not in use, thereby preventing rain water, other liquid, foreign bodies, or contaminants from entering the cooking device via its chimney. The chimney vent cap  100  is also configured by a user in the fully-closed configuration when the cooking device has been in use and the user desires to shut down (or at least temporarily slow) the combustion of fuel within the cooking device. This result occurs because, in the fully-closed, first configuration, the chimney vent cap  100  entirely blocks the flow of exhaust gases and prevents the entire flow of exhaust gases from passing through and exiting the chimney vent cap  100  into the surrounding environment, thereby creating maximal back pressure within the cooking device and substantially stopping the flow of fresh air into the cooking device for use in combustion. 
     More particularly, in the fully-closed, first configuration, the disc portion&#39;s central longitudinal axis  116  is coaxially aligned with the base member&#39;s central longitudinal axis  108  and, hence, with the central longitudinal axis  250  of the cooking device&#39;s chimney. Also, the bottom surface  126  of the control member&#39;s disc portion  114  rests atop and in contact with the entire bearing surface  182  of the base member&#39;s support portion  180  and fully occludes the base member&#39;s second opening  170  and prevents the flow of exhaust gases through the second opening  170  and plane  112 . Additionally, the control member&#39;s stop  144  depends into the base member&#39;s second opening  170  and is engaged against the second edge  188  of the base member&#39;s support portion  180 . 
     To configure the chimney vent cap  100  in the fully-closed, first configuration, the user grasps the grip member  106  and applies a force to the grip member  106  rotating the control member  104  about rotational axis  110  in the counterclockwise direction (indicated by arrow  252  in the top plan view of  FIG. 34 ). During such rotation, the fastener  142  substantially prevents vertical movement of control member  104  relative to the base member  102  such that the bottom surface  126  of the control member  104  slides against and atop the bearing surface  182  of the base member&#39;s support portion  180  in a single plane. Also, the stop  144  travels along an arc  254  (shown in dashed lines in  FIG. 35 ) about rotational axis  110  and toward the arc&#39;s first end  256 . When the stop  144  engages the second edge  188  of the base member&#39;s support portion  180  at the first end  256  of the arc  254 , the control member  104  cannot rotate further in the counterclockwise direction and the chimney vent cap  100  is in the fully-closed, first configuration. 
     According to the method of operation, the chimney vent cap  100  may be configured by a user in the fully-open, second configuration when the user desires to minimally block the flow of exhaust gases from the cooking device and chimney vent cap  100 , and to allow a maximum flow of exhaust gases to pass through and exit the chimney vent cap  100  into the surrounding environment. When configured in the fully-open, second configuration, the chimney vent cap  100  minimally blocks the flow of exhaust gases and produces minimal backpressure within the cooking device, thereby maximizing the flow of fresh air into the cooking device for use in combustion. By maximizing the amount of fresh air available for combustion, fuel is oxidized at a faster rate with the result being that the temperature within the cooking device increases. 
     More specifically, in the fully-open, second configuration, the disc portion&#39;s central longitudinal axis  116  is parallel to (but not collinear with) the base member&#39;s central longitudinal axis  108  and, hence, parallel to (but not collinear with) the central longitudinal axis  250  of the cooking device&#39;s chimney. Also, the bottom surface  126  of the control member&#39;s disc portion  114  rests atop and in contact with a minimal portion of the bearing surface  182  of the base member&#39;s support portion  180  and minimally occludes the base member&#39;s second opening  170 , allowing a maximum flow of exhaust gases through the second opening  170  and plane  112 . Additionally, the control member&#39;s stop  144  depends into the base member&#39;s second opening  170  and is engaged against the second edge  188  of the base member&#39;s support portion  180 . 
     To configure the chimney vent cap  100  in the fully-open, second configuration, the user grasps the grip member  106  and applies a force to the grip member  106  rotating the control member  104  about rotational axis  110  in the clockwise direction (indicated by arrow  260  in the top plan view of  FIG. 37 ) until the control member  104  cannot be rotated further. During such rotation, the fastener  142  substantially prevents vertical movement of control member  104  relative to the base member  102  such that the bottom surface  126  of the control member  104  slides against and atop the bearing surface  182  of the base member&#39;s support portion  180  in a single plane. Also, the stop  144  travels along arc  254  (shown in dashed lines in  FIG. 38 ) about rotational axis  110  and toward the arc&#39;s second end  258 . When the stop  144  engages the second edge  188  of the base member&#39;s support portion  180  at the second end  258  of the arc  254 , the control member  104  cannot rotate further in the clockwise direction and the chimney vent cap  100  is in the fully-open, second configuration. 
     When a user desires to establish a temperature within the cooking device different than that in the fully-closed, first configuration or the fully-open, second configuration, the chimney vent cap  100  may be configured in an intermediate, partially-open, third configuration in which the control member  104  is positioned between its rotational position in the fully-closed, first configuration and its rotational position in the fully-open, second configuration. In  FIGS. 39-41 , the chimney vent cap  100  is configured in such an intermediate, partially-open, third configuration in accordance with the method of operation. In such configuration, the flow of exhaust gases from the cooking device and chimney vent cap  100  into the surrounding environment is between the minimum flow of the fully-closed, first configuration and maximum flow of the fully-open, second configuration. Also, the backpressure within the cooking device is also between the minimum backpressure of the fully-open, second configuration and the maximum backpressure of the fully-closed, first configuration, resulting in the flow of fresh air into the cooking device and available for combustion being between its minimum and maximum and the temperature within the cooking device being between its minimum and maximum. 
     More particularly, in an intermediate, partially-open, third configuration, the disc portion&#39;s central longitudinal axis  116  is parallel to (but not collinear with) the base member&#39;s central longitudinal axis  108  and, hence, parallel to (but not collinear with) the central longitudinal axis  250  of the cooking device&#39;s chimney. Also, the bottom surface  126  of the control member&#39;s disc portion  114  rests atop and in contact with a moderate portion of the bearing surface  182  of the base member&#39;s support portion  180  and partially occludes the base member&#39;s second opening  170 , allowing an intermediate flow of exhaust gases through the second opening  170  and plane  112 . Additionally, the control member&#39;s stop  144  depends into the base member&#39;s second opening  170 , but is not engaged with the second edge  188  of the base member&#39;s support portion  180 . 
     To configure the chimney vent cap  100  in an intermediate, partially-open, third configuration, the user grasps the grip member  106  and applies a force to the grip member  106  rotating the control member  104  about rotational axis  110  in either the counterclockwise or clockwise direction (indicated, respectively, by arrows  252 ,  260  in the top plan view of  FIG. 40 ). During such rotation, the fastener  142  substantially prevents vertical movement of control member  104  relative to the base member  102  such that the bottom surface  126  of the control member  104  slides against and atop the bearing surface  182  of the base member&#39;s support portion  180  in a single plane. Also, the stop  144  travels along arc  254  (shown in dashed lines in  FIG. 41 ) about rotational axis  110  between the arc&#39;s first and second ends  256 ,  258 . When the chimney vent cap  100  has been configured in its desired intermediate, partially-open, third configuration with the control member  104  between its positions in the fully-closed, first configuration and the fully-open, second configuration, stop  144  resides at a corresponding intermediate location along arc  254  between the arc&#39;s first and second ends  256 ,  258 . 
     It should be understood and appreciated that because the stop  144  engages the second edge  188  of the base member&#39;s support portion  180  at the arc&#39;s first and second ends  256 ,  258 , the rotation of the stop  144  along arc  254  is limited by the base member&#39;s support portion  180  and, hence, the rotation of the control member  104  relative to the base member  102  is correspondingly limited to be between their positions in the fully-closed, first configuration and their positions in the fully-open, second configuration. Thus, the stop  144  serves to prevent excessive rotation of control member  104  relative to base member  102  about rotational axis  110  in either a clockwise or counterclockwise rotational direction. 
     It should also be understood and appreciated that, according to the method of operation and regardless of the then current configuration of the chimney vent cap  100  (and, hence, regardless of the rotational position of the control member  104  relative to the base member  102  about rotational axis  110 ), part of the control member&#39;s disc portion  114  is always kept elevationally above the magnet  200  embedded within the base member&#39;s support portion  180 . By keeping part of the control member&#39;s disc portion  114  above the magnet  200 , the relative rotational position of the base and control members  102 ,  104  is maintained until a force sufficient to overcome the magnet&#39;s attractive force is applied by a user to the grip member  106  to change the configuration of the chimney vent cap  100  from one configuration to another configuration. 
     In a second example embodiment, the chimney vent cap  100 ′ is substantially similar to the chimney vent cap  100  of the first example embodiment with the exception that the base member  102 ′ does not include a magnet to maintain the control member  104 ′ in the same position relative to the base member  102 ′ (and, hence, to maintain the chimney vent cap  100 ′ in the same configuration) prior to, during, and after movement of the lid of the cooking device during opening or closing of the lid. Instead, the chimney vent cap  100 ′ includes a washer and biasing member arranged about the shank of fastener  142 ′ between the fastener&#39;s head and the bottom surface  126 ′ of the control member  104 ′. More specifically, the washer is located between the fastener&#39;s head and the biasing member such that the biasing member contacts the washer and the bottom surface  126 ′ of the control member  104 ′. The biasing member is operable to exert a force pulling the control member  104 ′ toward the base member  102 ′ about rotational axis  110 ′ and is selected to allow a user to rotate the control member  104 ′ relative to the base member  102 ′ about rotational axis  110 ′ during use, but yet to maintain the control member  104 ′ in position relative to the base member  102 ′ before, during, and after opening and closing of the lid of the cooking device with which the chimney vent cap  100 ′ is used. According to the second example embodiment, the biasing member comprises a compression spring, but may comprise other devices having similar operation in other example embodiments. 
     According to a third example embodiment, the chimney vent cap  100 ″ is substantially similar to the chimney vent cap  100  of the first example embodiment. However, in the third example embodiment, the chimney vent cap  100 ″ includes no magnet, but one or both of the base member&#39;s bearing surface  182 ″ and the control member&#39;s bottom surface  126 ″ have a plurality of ridges, serrations, dimples, bumps, or other surface treatments or features, or combinations thereof, that are sized, spaced and oriented to substantially prevent the control member  104 ″ from rotating about rotational axis  110 ″ before, during, and after opening and closing of the lid of the cooking device unless a force is applied to the control member  104 ″, via the grip member  106 ″, by a user to cause such rotation. 
     In accordance with a fourth example embodiment, the chimney vent cap  100 ′″ is substantially similar to the chimney vent cap  100  of the first example embodiment with the exception that the base member  102 ′″ does not include a magnet, but one of the base member&#39;s bearing surface  182 ′″ or control member&#39;s bottom surface  126 ′″ has a protruding pin and the other of the base member&#39;s bearing surface  182 ′″ or control member&#39;s bottom surface  126 ′″ has a plurality of holes therein. The protruding pin and the plurality of holes are arranged relative to one another such that the protruding pin and the plurality of holes define a plurality of configurations of the control member  104 ′″ relative to the base member  102 ″. In each configuration, the control member  104 ′″ is rotated in a different angular position about rotational axis  110 ′″ and the protruding pin extends into a corresponding different hole of the plurality of holes. After a user imparts a force to the grip member  106 ′″ causing rotation of the control member  104 ′″ relative to the base member  102 ′″ about rotational axis  110 ′″, the control member  104 ′″ and base member  102 ′″ are arranged in a configuration in which the protruding pin extends into a different one of the plurality of holes than prior to such rotation. With the protruding pin residing in a hole, rotation of the control member  104 ′″ relative to the base member  102 ′″ is restricted, thereby allowing the lid of the cooking device to be opened or closed without movement of the control member  104 ′″ relative to the base member  102 ′″. 
     According to a fifth example embodiment, the chimney vent cap  100 ″″ is substantially similar to the chimney vent cap  100  of the first example embodiment. However, in the fifth example embodiment, the chimney vent cap  100 ″″ includes no magnet and the bore  140 ″″ extends through the disc portion  114 ″″ and between the disc portion&#39;s top and bottom surfaces  122 ″″,  126 ″″. Also, the hole  192 ″″ in the base member&#39;s end wall  166 ″″ extends only partially into the base member  102 ″″ and has an opening at the base member&#39;s second end  162 ″″. The hole  192 ″″ is threaded to receive a threaded pin therein. The threaded pin extends through bore  140 ″″ and into hole  192 ″″ such that the pin&#39;s threads are threadably engaged with the threads of hole  192 ″″. The threaded pin has a head that contacts the disc portion&#39;s top surface  122 ″″ when the threaded pin is fully threaded into hole  192 ″″, thereby securing the control member  104 ″″ in a particular configuration relative to the base member  102 ″″. When the threaded pin is threaded partially out of hole  192 ″″ by a user rotating the threaded pin, the control member  104 ″″ may be rotated relative to the base member  102 ″″ into a different configuration of the chimney vent cap  100 ″″. After fully threading of the threaded pin back into hole  192 ″″ by the user, the control member  104 ″″ and base member  102 ″″ are secured in such configuration and the lid of the cooking device may be opened and closed absent relative movement between the base member  102 ″″ and control member  104 ″″. 
     Whereas the present invention has been described in detail above with respect to example embodiments thereof, it should be appreciated that variations and modifications might be effected within the spirit and scope of the present invention.