Abstract:
A cooking apparatus including a housing having an interior which contains a heating device. The cooking apparatus includes a liner which is preferably made of metallic material with a bowl which may be removably placed therein to cook food. The heating device is a heating band which has downwardly extending foot members to prevent the heating element from contacting the floor of the housing to prevent hot spots and inadvertent burning of a users hand.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a apparatus for use in a electric cooking utensil known as a slow cooker or Crock-Pot® and more particularly to the heating element which is used for heating the bowl or basin used to contain the food being cooked. 
     2. Description of the Prior Art 
     A slow cooker is a type of cooking device that is well known in the art. An example of such a device is marketed by the assignee of this application under the trademark Crock-Pot® Slow cookers usually include a stoneware or ceramic vessel for holding the food. The stoneware vessel is removably insertable into a heating liner which is placed within a housing. The liner is generally a metallic basin or dish which follows the outer contours of the stoneware or ceramic vessel so that when the heated liner is activated, the heat will evenly distribute over the surface of the stoneware. Slow cookers typically have a selector switch having a high, low and off setting for varying heat settings which thereby affect the cooking time. 
     The heating units of slow cookers are typically simple devices. A slow cooker has an inner heat conductive, and usually metallic, liner which is used to evenly HEATING ELEMENT FOR A SLOW COOKER distribute heat over the stoneware vessel. The liner is usually heated by a thin heating element band which is wrapped around the exterior of the metallic basin. The heating element can be a simple heating band which is held on by a compression fit over the outside of the metallic basin. The liner typically has a ridge or similar structure that assists in securing the heating band around the liner. 
     Slow cookers rely on a slow even rate of cooking to function. Cooking time in slow cookers may be several hours. The low temperature of the cooking permits the user of the device to start cooking a meal in the morning and have it ready and properly cooked in time for dinner. Due to the slow cooking nature of the device, the contents of the stoneware need not be constantly monitored in order to prevent burning. In addition, the relatively low power and even distribution of heat of the slow cooker prevents hot spots from forming in the stoneware, which could lead to thermal stresses and ultimately cracking of the stoneware. The stoneware that is used acts as an insulator which is beneficial for slow cooking and an even distribution of the heat. Slow cookers allow simmering type cooking over several hours. 
     One advantage of using a slow cooker is that the devices are very easy to transport and may be moved to any place that the user desires due to their small size and easy portability. However, due to constant moving and usage of the slow cooker, prior designs have experienced problems with the heating element slipping off the metallic liner since it is usually held on by a compression fit. The heating element then falls onto the floor of the housing. 
     If the heating element is activated after falling on to the floor of the housing, a hot spot may be created. The hot spot on the outer housing creates a safety concern since the user may be unaware of the hot spot and be inadvertently burned. Furthermore, should the outer housing be made of a heat conductive material, the area where the slow cooker is placed may become hot or damaged. 
     It would be desirable to have a heating element which has a safety feature to eliminate the hot spot on the floor of the housing should the heating band become detached from the metallic liner. 
     It would further be desirable to have a safety feature which is easy to construct and could be used with pre-existing slow cooker designs and slow cooker heating elements. 
     SUMMARY OF THE INVENTION 
     The present invention is an electric cooking apparatus having an outer housing with an open upper end. The housing contains an inner heat conductive lining that is sized to fit within the outer housing to create an air space between the outer housing and the liner. The liner has a bottom with an upwardly extending sidewall. The liner is preferably made of a heat conductive material such as metal. A heating element is positioned in physical contact on the outer surface of the liner sidewall and is placed a distance above the liner bottom. The heating element includes several foot members extending downwardly from the heating element. The electric cooking apparatus further includes a cooking insert which is removably positioned inside of the liner. 
     In the preferred embodiment the heating element can be a metallic band which is positioned around the liner sidewall using a compression fit. The heating element can be controlled by a control means which allows for selectively controlling the heat output of the heating element. Preferably the control means has several settings such as off, low heat, and high heat. The heating element is preferably made of a heat conductive material such as aluminum or steel. The foot members are preferably positioned in equal distance from each other about the heating element. The foot members in the preferred embodiment are a predetermined length to prevent the heating element from touching the housing floor should the heating element become detached from the liner. 
     In the preferred embodiment, the cooking insert is made of a heat conductive material such as a ceramic, porcelain or metallic material. The cooking insert is positioned inside of the liner so that the sidewall of the cooking insert contacts the sidewall of the liner. The cooking insert is preferably has a bowl shape to hold food. A cover can be used to cover the cooking insert and the food contents while in use. The cover is preferably made of a translucent or clear glass. 
     A preferred form of the electric cooking apparatus, as well as other embodiments, objects, features and advantages of the present invention will be apparent from the following detailed description of illustrative embodiments thereof, which will be read in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top perspective view of the cooking apparatus of the present invention with a partial cut away showing the heating element; 
     FIG. 2 is an exploded perspective of the cooking apparatus of the present invention; 
     FIG. 3 is a left side elevational view of the cooking apparatus of the present invention with a partial cut away section along line  3 — 3  of FIG. 1 showing the heating element in place: and 
     FIG. 4 is a left side elevational view of the cooking apparatus of the present invention with a partial cut away section along line  3 — 3  of FIG. 1 showing the heating element detached from the liner. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a slow cooker apparatus having an improved heating element which prevents movement of the heating element from around the metallic liner to provide optimum safety in operation. 
     Referring initially to FIGS. 1 and 2, the cooking apparatus  10  of the present invention generally includes a housing assembly  12  and cooking insert  14  that is used to hold the food. The cooking insert  14  is essentially a pot used for slow cooking and is preferably formed of a stoneware material or a ceramic material of a type used to form standard slow cooker inserts. The cooking insert  14  is removably insertable within the housing assembly  12  so that the user may easily clean it when desired. In addition, a cover or lid  16  is further provided to cover the contents in the cooking insert  14 . The lid  16  may be made of clear glass so that the user may view the food that is being cooked. 
     Referring to FIG. 2, the housing assembly preferably includes a housing floor  18  which is parametrically bounded by an upwardly extending sidewall  20  ending in a rim  22 . The floor  18  and sidewall  20  define a housing interior  24 . The sidewall  20  may include a pair of outwardly extending handles  26  in order to permit an individual to carry the cooking apparatus  10 . The housing interior  24  includes an inner surface  28 . A liner  30  which is preferably formed of a heat conducting material such as aluminum or steel is provided within the housing  12 . The liner  30  conforms to the shape of the inner surface of the sidewall  20  and floor  18  and is configured to receive the cooking insert  14 . The liner  30  is preferably sized smaller than the housing  12 , whereby an air space  32  is created between the liner  30  and the housing  12  so that a heating element  40  may be placed around the liner  30  between the housing  12  and the liner  30 . The liner  30  has a liner sidewall  34  extending from a bottom wall  35  to a lip  36  which extends over to the sidewall  20  of the housing  12  to close off the air space  32 . 
     In order to heat the food contents within the cooking insert  14 , a heating element  40  is positioned about the outer surface  38  of the liner  30 . A heating element  40  preferably includes a plurality of resistance type elements (not shown) formed in a band which is wrapped around the liner sidewall  34 . When the heating element  40  is supplied with power, heat is created and then transferred to the liner sidewall  34 , which through conduction, carries the heat throughout the liner  30 . The liner  30  distributes the heat to the cooking insert  14  that is positioned within the liner  30 . In order to protect the housing sidewall  20  and floor  18  from the heat, the air space  32  which is between the liner  30  and the housing  12  is of a sufficient distance so that only the liner  30  becomes hot. In an alternative embodiment (not shown) there may be sidewall insulation on the housing to further reduce the chance that the heating element will transfer any heat to the housing. 
     Referring to FIGS. 2 and 3 the cooking insert  14  is configured to closely follow the contour of the liner  30 . In the preferred embodiment the cooking insert  14  is made of a ceramic or stoneware material and contacts the liner  30  when correctly positioned in the cooking apparatus  10 . The cooking insert  14  has a bottom wall  50  surrounded by an upwardly sidewall  52  which ends in the outwardly extending annular flange  54 . When the cooking insert  14  is placed within the liner  30  in the housing  12 , the flange  54  is supported by the housing rim  22  and sidewall  20 , while the bottom wall  50  extends into the housing interior  24 . 
     The heating element  40  may include a control circuit  60  which is used to vary the heat produced by the heating element  40 . The control circuit  60  preferably includes a controller in the form of a user actuatable selector switch  62 . The selector switch  62  may be chosen from any number of switches on the market that are well known in the art. Preferably, the selector switch  62  may include three discrete positions, off, low and high. An indicator light such as an LED may be provided to indicate that the selector switch is in the low or high position (not shown). The user may select either the low or high setting depending on the food that is being cooked in the slow cooker. The selector switch  62  is connected with the control circuit  60  such that it receives current directly from the power source and then supplies the needed current to the heating element  40 . The selector switch  62  is preferably located on the housing sidewall  20 . A dial  64  positioned on the outside of the sidewall  20  may be provided to permit a user to actuate the selector switch  62 . The selector switch  62  may have an automatic function contained therein so that the amount of current supplied to the heating element  40  will not go above a predetermined level. 
     The heating element  40  will now be described in further detail. Referring to FIG. 2, the present invention includes a heating element  40  which is positioned in close proximity with the liner  30 . The heating element  40  is preferably a band type heating element which is well known in the art, and is not described in detail. The heating element  40  typically involves using resistance coils on the inside of a metallic band which are wrapped in mica paper as insulation. Such heating bands are known by those skilled in the art. The heating element  40  may be made of either aluminum or steel. 
     The heating element  40  preferably contacts the liner  30  and wraps completely around the outer surface  38 . The heating element  40  may be a one piece band which wraps completely around the liner  30 . In the preferred embodiment, the heating element  30  has a first end  42  and a second end  44  which are held together to form the complete band. The first end  42  and second end  44  are preferably held together by the use of a resilient member  46  to form a compression fit around the liner  30 . The resilient member  46  may be a spring which holds the first end  42  and second end  44  together. The heating element  40  may be further secured to the liner  30  by a raised rib  48  that is integrally molded into the outer surface  38  of the liner  30 . In the preferred embodiment, the rib  48  extends laterally completely around the outer surface  38  so that the heating element  40  may be placed above the rib  48 . The compression fit of the heating element  40  may be positioned above the rib  48  to further prevent the heating element  40  from falling off of the liner  30 . Prior designs have used this common method of attaching the heating element  40 . 
     Due to the portability of the slow cooker, the user may constantly move the apparatus to different locations. Such movement could jostle the heating element  40  enough to partially remove it from the liner  30  or cause it to fall completely off the liner  30 . In addition, the resilient member  46  may either break or become loose. Should the compression fit of the heating element  40  around the liner  30  fail, the heating element  40  may fall off the liner  30  and onto the housing floor  18 . 
     A safety hazard is created by the heating element  40  falling off the liner  30 . If the heating element  40  is activated when it touches the housing floor  18 , it may cause the housing floor  18  to become hot if the housing floor  18  is made of a heat conductive material. In addition, if the housing  12  is made of a heat conductive material it is possible that the area where the slow cooker is placed, such as a countertop, may be damaged by the heat transfer from the housing  12 . Furthermore, some slow cookers may have a housing  12  made of a high strength plastic which is heat resistant but may melt after prolonged exposure to heat such as when the heating element  40  may fall onto the housing floor  18 . The present invention addresses the safety issue regarding the heating element  40  falling on the housing floor  18  and provides an added measure of safety to using the slow cooker. 
     Referring to FIGS. 2 and 3, the present invention has a plurality of foot members or extensions  70  extending downwardly from the heating element  40 . Preferably these extensions  70  are of a length so that the heating element  40  does not touch the housing floor  18  should it become detached from contacting the liner  30 . The extensions  70  are preferably placed an equal distance from each other so that the heating element  40  is held at a level height when placed on a flat surface. The extensions  70  may be made in any shape, so long as they can support the heating element above the floor of the housing. 
     The extensions  70  are preferably of a length so that they do not interfere with the proper mounting of the heating element  40  on the liner  30  or the functioning of the heating element  40  when activated. The extensions  70  may be made of any material which provides strength and is resistant to the heating effects of the heating element  40  being turned on and off. The extensions  70  are preferably made of the same material as the heating element  40  such as aluminum or steel and may be welded using tack welds to the heating element  40 . Alternatively, the extensions  70  may be made from a heat resistant material such as plastic, which will not conduct heat to the housing floor in case of slipping off the liner. The present invention provides an added safety measure to the slow cooker should the heating element  40  be inadvertently detached. 
     Referring to FIG. 3, the present invention has a heating element  40  attached with a compression fit to the liner  30 . The extensions  70  in the preferred embodiment do not touch the housing floor  18  when the heating element  40  is properly attached to the liner  30 . The heating element  40  is attached to the liner  30  with a compression fit above the rib  48  in the liner outer surface  38 . The extensions  70  do not in any way change or interfere with the operation of the cooking apparatus  10  when the heating element  40  is properly positioned. 
     Referring now to FIG. 4, the heating element  40  of the present invention is shown to be detached from the liner  30 . The compression fit of the heating element  40  has failed, and the heating element  40  is no longer positioned correctly on the liner  30 . The extensions  70  on the heating element  40  are shown to contact the housing floor  18  and the heating element  40  is spaced a distance DI from the housing floor  18 . The heating element  40  will not create a hot spot in the housing floor since the extensions  70  effectively stop the heating element  40  from touching the housing floor  18 . 
     Thus while there has been described what are presently believed to be preferred embodiments of the present invention, other and further modifications and changes can be made thereto without departing from the true spirit of the invention. It is intended to include all further and other modifications and changes that would come within the true scope of the invention as set forth in the claims.