Abstract:
A passive heater including a carriage actuatable to move along a cooking surface and a cover. In one exemplary embodiment, the carriage may be positioned on a guide bar to direct movement of the carriage along the cooking surface. The cover may be connected to the carriage and positionable near the cooking surface. Advantageously, positioning the cover near the cooking surface provides for the retention of nearby heat. Thus, the top surface of a food item cooking on the cooking surface may be heated by placing the cover over the food item. In another exemplary embodiment, the cover has a lifted position and a lowered position. By moving the cover from the lifted position to the lowered position, the cover may contact the cooking surface to surround food cooking thereon. In another exemplary embodiment, the lowered positioned may be spaced upwardly from the cooking surface, allowing the cover to cap food thereon.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit under Title 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/884,269, entitled PASSIVE HEATER, filed on Jan. 10, 2007, the entire disclosure of which is expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to a passive heater, particularly to a passive heater for use in conjunction with a cooking surface. 
     2. Description of the Related Art 
     Numerous devices having heated cooking surfaces are utilized in the food service industry. These devices may be formed as griddles or stoves, for example, having heated cooktops upon which food to be cooked is placed. These devices transfer thermal energy from the cooktop to the bottom of the food thereon. Once the bottom surface of the food is sufficiently cooked, the food may be flipped or otherwise repositioned so that different surfaces of the food are in direct contact with the cooktop. During cooking, it may be desirable to keep the top surface, i.e., the surface not in contact with the cooktop, of the food warm. Similarly, cheese or other condiments which need to be heated may be added to the top surface of a hamburger, for example. 
     SUMMARY 
     The present invention relates to a passive heater, particularly to a passive heater for use in conjunction with a cooking surface. In one exemplary embodiment, the passive heater includes a carriage actuatable to move along a cooking surface and a cover. In one exemplary embodiment, the carriage may be positioned on a guide bar to direct movement of the carriage along the cooking surface. The cover may be connected to the carriage and may be positionable near the cooking surface. Advantageously, positioning the cover near the cooking surface provides for the retention of nearby heat. Thus, the top surface of a food item cooking on the cooking surface may be heated by placing the cover over the food item. In another exemplary embodiment, the cover has a lifted position and a lowered position. By moving the cover from the lifted position to the lowered position, the cover may contact the cooking surface to surround food cooking thereon. Advantageously, by positioning the cover to surround uncooked food, contact between the uncooked food and any other food on the cooking surface is substantially prevented. In another exemplary embodiment, the lowered position of the cover may space the cover upwardly from the cooking surface, allowing the cover to cap food thereon. 
     Advantageously, the present passive heater provides for the heating of a food item on a cooking surface, without the need to create thermal energy in addition to the thermal energy created by the cooking surface. This allows the passive heater to function without components, such as active radiant, conductive, or convective heating elements, which require additional energy inputs. As a result, use of the passive heater may decrease operating costs. Further, the lack of sensitive components, such as electrical connections, makes the passive heater easier to clean, reducing labor costs. Additionally, the use of the present passive heater allows for the retention of moisture around the food cooking on the cooking surface. This helps to prevent the food from drying out during cooking. 
     In one form thereof, the present invention provides a passive heater including a carriage actuatable to move along a cooking surface, and a cover connected to the carriage, whereby actuation of the carriage moves the cover along the cooking surface, the cover positionable to contact the cooking surface, whereby heat is retained between the cover and the cooking surface. 
     In another form thereof, the present invention provides a passive heater including a carriage positioned adjacent a cooking surface, wherein the carriage may be actuated to move along the cooking surface, and a cover having a lifted position and a lowered position, the cover capable of being moved from the lifted position to the lowered position to cap food on the cooking surface. 
     In another form thereof, the present invention provides a method of heating food on a cooking surface including the steps of actuating a passive heater having a carriage and a cover to position the cover over food on the cooking surface, and lowering the cover toward the cooking surface to at least partially cap the food while maintaining the position of the carriage. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of the passive heater of the present invention adjacent a cooking surface; 
         FIG. 2  is a partial perspective view of the passive heater and cooking surface of  FIG. 1 ; 
         FIG. 3  is a partial cross sectional view of the passive heater and cooking surface of  FIG. 1 , taken alone line  3 - 3  of  FIG. 1 ; 
         FIG. 4  is a partial cross sectional view of the passive heater and cooking surface of  FIG. 1 , taken along line  4 - 4  of  FIG. 2 ; 
         FIG. 5  is an exploded view of the passive heater of  FIG. 1 ; and 
         FIG. 6  is an assembly view of another embodiment of the passive heater of  FIG. 1 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , passive heater  10  is shown positioned adjacent cooking surface  12  of griddle  14 . While passive heater  10  is described and depicted herein with specific reference to cooking surface  12  of griddle  14 , passive heater  10  may be utilized with any device having a cooking surface, such as a halogen cook top or a charbroiler. Additionally, as stated above, the device of the present invention is a passive heater. Passive heaters lack a heating element which generates thermal energy, such as an active radiant heating element. In a passive heater, the system only controls or directs thermal energy in a useful way. In contrast, in an active heater, a component of the system generates thermal energy and the system utilizes the thermal energy so generated in performing its intended function. 
     Passive heater  10  includes carriage  16  and cover  18 , as best seen in  FIG. 5 . Carriage  16  may be actuated to move cover  18  over cooking surface  12 . As shown in  FIG. 5 , carriage  16  includes first end  20  and second end  22 . First end  20  and second end  22  are connected via rails  24  positioned therebetween. As shown in  FIGS. 1-6 , carriage  16  further includes top surface  26  connected between rails  24  and first and second ends  20 ,  22 . As shown in  FIG. 5 , rails  24  of carriage  16  include apertures  28  formed therein. In one exemplary embodiment, carriage  16  lacks top surface  26 . In this embodiment, at least a portion of cover  18  of passive heater  10  may be viewed from directly above passive heater  10 . 
     As shown in  FIGS. 3-5 , cover  18  includes top surface  19  and downwardly extending sides  30  having bottom surfaces  32 . Sides  30  of cover  18  further include apertures  34  formed therein. Apertures  34  of cover  18  and apertures  28  of carriage  16  are sized to receive pins  36  of connecting arms  38 . Connecting arms  38  provide the connection between carriage  16  and cover  18 , and also facilitate movement of cover  18  relative to carriage  16 . In one embodiment, connecting arms  38  includes opposing pairs of resiliently deformable legs. As shown in  FIG. 5 , connecting arms  38  include a pair of lower legs  40  and a pair of upper legs  42 . 
     To attach cover  18  to connecting arms  38 , lower legs  40  of connecting arms  38  are expanded, i.e., pulled apart from one another, and pins  36  of lower legs  40  are positioned within apertures  34  of sides  30  of cover  18 . Similarly, to attach connecting arms  38  to carriage  16 , upper legs  42  are contracted, i.e., pressed together, and pins  36  of upper legs  42  are positioned within apertures  28  of rails  24  of carriage  16 . As described in detail above, lower legs  40  and upper legs  42  are attached to cover  18  and carriage  16 , respectively, via pins  36 . However, lower legs  40  and upper legs  42  of connecting arms  38  may be connected to cover  18  and carriage  16 , respectively, in any known manner, such as by bolts. 
     With cover  18  connected to carriage  16 , as described in detail above, carriage  16  may be slid along cooking surface  12  to position carriage  16  and cover  18  in the desired orientation. Additionally, handle  44  is positioned within slot  46  of second end  22  of carriage  16 , allowing a user to grasp handle  44  to facilitate movement of carriage  16  and/or cover  18 . As shown in  FIG. 5 , guide bar  48  may be utilized to direct movement of carriage  16 . Specifically, tab  50  of first end  20  of carriage  16  may be positioned within clamp  52 . Clamp  52  is then attached to guide bar  48  via rollers  54  and support block  56 . Guide bar  48  may then be secured to brackets  58  via bolts  60 . With carriage  16  connected to guide bar  48 , as shown in  FIGS. 3 and 4 , guide bar  48  will direct movement of carriage  16  in the direction of arrows A of  FIG. 1 . As shown in  FIG. 5 , movement of carriage  16  will be limited by rollers  54  and brackets  58 . 
     Second end  22  of carriage  16  can, in certain embodiments, include guide members, such as wheels  62  or other components designed to reduce friction between carriage  16  and cooking surface  12 , which facilitate movement of carriage  16 . In this embodiment, wheels  62  can cooperate with a guide bar similar to guide bar  48  positioned adjacent second end  22  to direct movement of carriage  16  along cooking surface  12 . Additionally, as shown in  FIGS. 1-4 , carriage  16  may be positioned with wall  64  of griddle  14  separating guide bar  48 , and its related components described above, from cooking surface  12 . In this embodiment, guide bar  48  and its related components are prevented from contacting food cooking on cooking surface  12 . To facilitate cleaning of passive heater  10  or allow it to be used on another cooking surface, carriage  16  (together with passive heater  10 ) may be removed from clamp  52 , as shown in  FIG. 6 , and separated from guide bar  48 . 
     In use, passive heater  10  may cover and/or cap food items cooking on cooking surface  12 . With reference to  FIG. 1 , passive heater  10  may be positioned over a row of food items, such as hamburgers  66 . While the operation of passive heater  10  is described and depicted herein with specific reference to hamburgers  66 , the passive heater of the present invention may be utilized with any food items positioned on a cooking surface, such as eggs, chicken, and sausage. Once in this position, cover  18  may be moved from a lifted position, shown in  FIGS. 1 and 3 , to a lowered position, shown in  FIGS. 2 and 4 , in which bottom surfaces  32  of cover  18  contact cooking surface  12 . Referring to  FIG. 3 , when cover  18  is in the lifted position ( FIGS. 1 and 3 ), protrusion  72  of resiliently deformable retainer  74  contacts bottom surface  32  of cover  18  to retain cover  18  in the lifted position. Retainer  74  is secured to second end  22  of carriage  16  by screw  76 . However, retainer  74  may be secured to carriage  16  in any known manner, such as by rivets. To move cover  18  from the lifted position ( FIGS. 1 and 3 ) to the lowered position ( FIGS. 2 and 4 ), a downward force is exerted on handle  44 . When the force on handle  44  is sufficient to deform retainer  74  toward second end  22  of carriage  16 , cover  18  can be moved to the lowered position until bottom  32  contacts cooking surface  12 . 
     With cover  18  in the lowered position ( FIGS. 2 and 4 ), retainer  74  moves into an unbiased position extending toward first end  20  of carriage  16 . To move cover  18  back into the lifted position ( FIGS. 1 and 3 ), an upward force is exerted on handle  44 . When the force exerted on handle  44  is great enough to sufficiently deform retainer  74  toward second end  22 , cover  18  may be moved upward until bottom surface  32  of cover  18  pass protrusion  72  of retainer  74 . The force exerted on handle  44  may be released and cover  18  is held in the lifted position ( FIGS. 1 and 3 ) by the interaction of protrusion  72  of retainer  74  with bottom surface  32  of cover  18 . During movement of cover  18  from the lifted position to the lowered position, and vice versa, the position of carriage  16  may be maintained. 
     Referring to  FIG. 4 , when cover  18  is positioned over a row of hamburgers  66  and moved into the lowered position, as described above, passive heater  10  functions as a barrier to prevent the escape of thermal energy from cooking surface  12  near hamburgers  66 , as well as from hamburgers  66  themselves. Specifically, cover  18  retains heated air and moisture near hamburgers  66  to speed the cooking thereof. Thus, even after being “flipped”, upper surface  68  of hamburgers  66 , which are no longer in contact with cooking surface  12 , may continue to cook, providing a fully cooked hamburger in less time. Additionally, once hamburgers  66  are substantially fully cooked, cheese may be placed thereon and cover  18  lowered to quickly melt the same. 
     With cover  18  in the position shown in  FIGS. 2 and 4 , a second row (not shown) of hamburgers  66  may be placed adjacent to the first row positioned under cover  18 . In this exemplary embodiment, the area of cover  18  is less than one-half the area of cooking surface  12 . Thus, once hamburgers  66  positioned beneath cover  18  are fully cooked, which may be determined by measuring the total cook time, cover  18  may be raised and carriage  16  may be moved to center cover  18  above the second row of hamburgers  66  (not shown). Cover  18  can then be moved from the lifted position to the lowered position and contact between cooked and uncooked hamburgers  66  is substantially prevented. 
     In one exemplary embodiment, cover  18  may be moved from a lifted position, shown in  FIG. 1 , to a lowered position, in which bottom surfaces  32  of cover  18  are spaced apart from cooking surface  12  by a predetermined distance. In this embodiment, connecting arms  38  are shortened by a predetermined amount, corresponding to the predetermined distance, to position bottom surfaces  32  above cooking surface  12 . Specifically, when cover  18  is in the lowered position, connecting arms  38  extend substantially perpendicularly to cooking surface  12  and space bottom surfaces  32  the predetermined distance from cooking surface  12 . This allows cover  18  to cap hamburgers  66 . By capping hamburgers  66 , enough thermal energy to heat upper surface  68  of hamburgers  66  is retained beneath cover  18 , while additional thermal energy may escape through the space between cooking surface  12  and cover  18 . This allows the user to accommodate variations in cooking temperatures of different food items, for example. In another exemplary embodiment, a detent mechanism may be used to retain cover  18  at a midpoint where bottom surfaces  32  of cover  18  are spaced apart from cooking surface  12  by a predetermined distance. In this embodiment, the detent mechanism may allow for bottom surfaces  32  of cover  18  to be positioned and retained at a plurality of different predetermined distances from cooking surface  12 . Additionally, in one exemplary embodiment, the detent mechanism may further allow cover  18  to be positioned with bottom surfaces  32  contacting cooking surface  12 . 
     In another exemplary embodiment, tabs  70 , shown in  FIG. 6 , are connected to bottom surfaces  32  such that they extend downward therefrom and toward cooking surface  12 . Thus, when cover  18  is moved to the lowered position, tabs  70  contact the cooking surface and retain bottom surfaces  32  of cover  18  spaced apart from cooking surface  12 , as described in detail above. Further, an additional pair of tabs  70  may be positioned on the opposing side of cover  18  opposite the pair of tabs  70  shown in  FIG. 6 . While described and depicted herein as opposing pairs of tabs, a plurality of tabs  70  may be provided in any number and may take any configuration, such as extending for bottom surfaces  32  of cover  18  at opposing ends of cover  18 . 
     Advantageously, the use of tabs  70  prevents connecting arms  38  from extending downward into a vertical position relative to cooking surface  12 . This allows for cover  18  to move substantially vertically when handle  44  is initially raised. In contrast, when connecting arms  38  are in a vertical position relative to cooking surface  12 , the first movement of handle  44  away from cooking surface  12  results in cover  18  moving substantially horizontally relative to cover  18 . 
     In one exemplary embodiment, bottom surface  32  of cover  18  is positioned between cooking surface  12  and upper surface  68  of hamburgers  66 . In another exemplary embodiment, passive heater  10  is configured so that when cover  18  is in the lowered position, cover  18  is no more than three inches from cooking surface  12  and bottom surface  32  extends below the top surface of the food to be cooked. 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.