Patent Publication Number: US-2007113838-A1

Title: Gas-fired cooking griddle

Description:
FIELD OF THE INVENTION  
      The present invention relates to gas fired cooking appliances, and, more particularly, the invention pertains to the control of a gas fired cooking griddle that may be independent or part of a cooking range.  
     BACKGROUND OF THE INVENTION  
      Gas fired cooking ranges are used in both residential and commercial kitchens. A basic design for a gas fired range includes a gas supply source, a manifold and one or more burner assemblies for receiving gas from the gas supply source via a connection to the manifold. It is also known to provide a cooking griddle as part of the cook top. It is further known to provide cooking griddles independent of gas fired, open flame cooking tops.  
      A cooking griddle is known to provide a substantially continuous flat cooking surface on which food items can be placed directly for cooking.  
      Whereas open flame cooking tops are generally used with cooking utensils such as pots or pans, a griddle can be used by placing the food directly on the griddle surface. While a utensil can be placed on a griddle, it is more common that the food is cooked directly on the griddle surface, without an intervening utensil.  
      Many different types of foods can be prepared on a griddle, including by way of example and without limitation, hamburgers and other meats, eggs, pancakes and the like.  
      In known designs, the griddle top is supported on a support structure in the range or independent griddle frame, with outer sheeting panels of the appliance substantially meeting the outer edge of the griddle top. One or more burners, often of an elongate form, are provided in a space beneath the griddle top. The burner or burners are connected to a gas manifold in the appliance, to which cooking gas is provided. A valve controls the flow of gas from the manifold to the burner.  
      Several problems and inconveniences have been experienced with known cooking griddles. The griddle burner is confined in a substantially enclosed space, with limited viewing access thereto. Accordingly, someone operating and adjusting the burner for the desired heating of the griddle cannot easily see the flame emanating from the burner. Unlike open burners of cook tops, it is difficult for a cook to knowingly adjust the griddle burner to a desired heat setting. Experienced cooks viewing an open flame of a cook top can easily judge the performance of the burner for the utensil being used and the food being prepared. The same is not true for griddle adjustment in which the burner cannot be seen easily. Accordingly, cooks have resorted to peering through cracks, spaces and small openings in the housing in an attempt to see the griddle burner flame. This is especially problematic in commercial kitchens in which one setting may be desired early in the morning when preparing breakfast foods such as pancakes, eggs, bacon or the like and then another setting for the preparation of lunch or dinner foods including meats such as hamburgers, chicken breasts or the like.  
      In addition to limited viewability of the burner flame, adjustment of griddle burners has been difficult in that only limited rotation is available for turning the valve and adjusting the gas flow. Griddle valves have typically rotated a maximum of 90°, with perhaps only 40 to 45° actually varying the gas flow, with the remainder of the rotation not affecting gas flow. Rotation through only a narrow arc can cause a significant change in the gas flow, and a correspondingly significant change in burner output. Accordingly, it has been difficult to control the temperature of griddles, with the control not being very precise. Thermostatically controlled valves are known, with a bulb and capillary sensor adjusting gas flow to a desired heat setting. However, such thermostatically controlled valves are expensive and subject to failure.  
      What is needed is a griddle burner control providing easier and more accurate control of griddle heating.  
     SUMMARY OF THE INVENTION  
      The present invention provides a griddle with a control valve having a larger range through which the valve can be rotated and over which it will control the flow of gas. The control knob is provided with indicia for indicating the valve position.  
      An advantage of the present invention is providing a griddle that is more easily adjusted and more precisely controlled than known griddle burner arrangements.  
      Another advantage of the present invention is providing a griddle burner assembly that is more conveniently used than known burner assemblies.  
      Still another advantage of the present invention is providing a griddle assembly with improved heating accuracy that can be provided more cost effectively than known thermostatically controlled griddle assemblies.  
      Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a perspective view of a gas-fired cooking range having a griddle in accordance with the present invention;  
       FIG. 2  is a fragmentary, enlarged perspective view of the area of griddle valves, with control knobs, on the range showed in  FIG. 1 ;  
       FIG. 3  is a perspective view of the gas circuit in the range shown in  FIG. 1 ;  
       FIG. 4  is an enlarged plan view of a knob for the valves of the griddle; and  
       FIG. 5  is a perspective view of the cook top on the range, with the grates and griddle top removed.  
      Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
      Referring now more specifically to the drawings and to  FIG. 1  in particular, numeral  10  designates a gas-fired cooking range having a griddle area  12  and a gas circuit  14  ( FIG. 3 ) in accordance with the present invention. The present invention can be used for various cooking appliances including commercial ranges, residential ranges and independent cooking griddles that are not part of a cooking range. The embodiment shown in  FIG. 1  is merely an exemplar of an application of the present invention.  
      Griddle area  12  is part of a cook top  16  that further includes two open-flame cooking locations  18  and  20 . Range  10  further includes an oven  22  accessed through a door  24  having a handle  26 . Legs  28  support range  10 , and can be pedestal-like supports as shown, or can be wheels or casters to facilitate moving range  10  for cleaning  
      Gas circuit  14  includes a main gas line  30  connected to a gas fuel source such as, for example, a natural gas line from a natural gas utility, a propane tank or the like. Those skilled in the art will readily understand that additional equipment not shown, such as a pressure regulator, main shut off valve and other suitable and required equipment, fittings and the like are provided as necessary for coupling main gas line  30  to the source of gaseous fuel and to control and regulate the flow of gaseous fuel. For example, main gas line  30  can be connected to the fuel source via a flexible hose (not shown) to allow cooking range  10  to be moved a short distance for cleaning the kitchen in which it is used.  
      Main gas line  30  supplies gas to a gas manifold  32  extending along the front, top area of range  10 . A cook top gas shutoff valve  34  is provided at the inlet end of manifold  32 , upstream of cook top gas flow control valves to be described subsequently herein that are in flow communication with manifold  32 .  
      Shutoff valve  34  can be used to initiate or terminate the flow of gas from gas line  30  to manifold  32 . Thus, by closing shutoff valve  34 , the flow of gas from gas line  30  to manifold  32  can be stopped, without interrupting the flow of gas from gas line  30  to an oven branch gas line (not shown) connected at a coupling  36  upstream of cook top shutoff valve  34 .  
      An open flame burner assembly  40  ( FIG. 5 ) provides open flames for open-flame cooking locations  18  and  20 . Open flame burner assembly  40  has burner heads  42 ,  44  at cooking locations  18 ,  20 , respectively. Burner heads  42 ,  44  are connected in gas flow communication to manifold  32  via an orifice defined at open flame burner control valves  46  and  48 , respectively. Each control valve  46 ,  48  is provided for initiating, terminating and controlling the flow rate of combustible gas from manifold  32  to a different burner head  42 ,  44 , respectively.  
      The manner in which control valves  46 ,  48  are installed and used is well known to those skilled in the art and will not be described in further detail herein.  
      A pilot light connection  50  is provided for supplying gas from manifold  32  to pilot gas lines  52 ,  54 , respectively, for burner heads  42 ,  44 .  
      Burner assembly  40 , as described previously includes two burner heads  42 ,  44 . However, it should be understood that separate individual burner assemblies can be provided for each open flame cooking location  18  and  20 .  
      Burner heads  42 ,  44  are substantially annular bodies defining open top annular channels with burner head covers  56 ,  58  provided thereon respectively.  
      Each cover  56 ,  58  has a plurality of holes  60  therein through which a mixture of combustion gas and primary combustion air is emitted.  
      Burner assembly  40  includes a single piece, monolithic casting forming a first venturi  62  and a second venturi  64  together with burner heads  42 ,  44  in back and front locations respectively on range  10 . As known to those skilled in the art, each venturi  62 ,  64  is aligned with a different burner control valve  46 ,  48  to receive gas therefrom when the control valve  46 ,  48  is opened to allow gas to flow therethrough from manifold  32 . As known to those skilled in the art, venturis  62 ,  64  also admit a flow of ambient air to mix with the combustion gas in venturis  62 ,  64  via one or more openings  66 ,  68  defined in baffle plates  70 ,  72  respectively.  
      In the assembled cooking range  10 , grates  74 ,  76  respectively are provided at open flame cooking locations  18 ,  20  above burner heads  42 ,  44  for supporting cooking utensils such as pots and pans.  
      As illustrated most clearly in  FIGS. 1 and 5 , griddle area  12  includes a griddle top  80  defining a cooking surface  82 . A back  84  and sides  86 ,  88  tapering from the back to the front of griddle top  80  are provided at the periphery of cooking surface  82  to confine foods on surface  82 . Griddle top  80  is supported in range  10  along an outer side rail  90  and along an intermediate support  92  defined in the main body of range  10 . A back panel  94  and front ledge  96  together with the aforementioned side rail  90  and support  92  define a substantially enclosed space  98  beneath griddle top  80 .  
      First and second griddle burners  100 ,  102  are provided in space  98 , beneath griddle top  80 . Griddle burners  100 ,  102  are in gas flow communication with manifold  32  via griddle control valves  104  and  106 , respectively. Each griddle control valve  104 ,  106  includes a valve body  108 ,  110  engaged in an opening  112 ,  114  in manifold  32 . Valve stems  116 ,  118  control and adjust flow of gas through valve bodies  112 ,  114 .  
      Valves  104 ,  106  are opened by rotating stems  116 ,  118  from a closed position to a fully open position. In contrast to known griddle control valves that have minimal rotation between fully closed and fully opened positions, stems  116 ,  118  rotate at least about 180° through which the flow of gas varies. In a preferred embodiment for griddle control valves  104 ,  106  stems  116 ,  118  have a total rotation of about 250° with a control range therein of at least approximately 180° for the control of gas flow.  
      Thus, valves  104 ,  106  have significantly greater total rotation and significantly greater rotation through which gas flow is adjusted than known griddle control valves having a total rotation of about 90° and a rotation less than 90° over which effective variation in gas flow can be achieved. With a greater arc through which valves  116  and  118  can be rotated while controlling gas flow, finer control of gas flow is possible, and thus a finer control of the intensity of flames from burners  100 ,  102 .  
      When griddle area  12  is completely assembled, with griddle top  80  disposed and supported in its cooking position, space  98  is substantially enclosed.  
      Observing burners  100 ,  102  for evaluating the height and intensity of flames coming therefrom is difficult. Thus, controlling heating of surface  82  is difficult.  
      In accordance with the present invention, valves  104 ,  106  are provided with control knobs  120 ,  122  respectively, on stems  116 ,  118  and by which stems  116 ,  118  can be rotated for increasing or decreasing gas flow to burners  100 ,  102  and thereby the intensity of flames from burners  100 ,  102 . Knobs  120 ,  122  are similar, with knob  120  being shown in  FIG. 4 .  
      Each knob  120 ,  122  includes markings or indicia  124  by which the relative position of knob  120 ,  122  can be evaluated, and thereby the rotational positions of valve stem  116  or  118 , respectively. Thus, by evaluating the rotational position of knob  120  or  122  the intensity of flame and thereby the heat supplied to cooking surface  82  can be evaluated. Indicia  124  include an “off” position mark  126  and a fully “on” position mark  128 , with one or more intermediate markings  130 ,  132  indicating intermediate positions for stems  116 ,  118  and thereby intermediate flame intensities and intermediate heating levels for surface  82 . Indicia such as reference marks  134 ,  136  adjacent knobs  120 ,  122  on a viewable surface of range  10  provide references by which to evaluate the relative rotational positions of indicia  124 .  
      To ignite griddle burners  100 ,  102 , griddle pilot light assemblies  138 ,  140  are provided connected to manifold  32  via pilot system valves  142 ,  144 . Other types of igniters also can be used.  
      The present invention provides more precise flame control by providing a more readily adjustable valve having greater rotation and thereby more precisely controlled variation in the flow of gas as the valve is rotated between fully closed and fully open positions. The knob provides indicia or indicators as reference points by which an operator can select a setting for the rotational position of the valve stems. As a result, even without a thermostatic control, relative heating for surface  82  can be duplicated from one cooking session to the next by rotating knobs  120 ,  122  to similar reference positions during each successive cooking session. Rather than waiting for warm-up and testing, a cook can position one or more of valves  104 ,  106  to an acceptable setting determined from a previous cooking session, and can rely on substantially similar heating for surface  82 . The indicia provide ready reference points for duplicating the rotational position from one cooking session to the next.  
      Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art.  
      Various features of the invention are set forth in the following claims.