Abstract:
An air intake heater for use in a motor vehicle has an engine with an engine block and an intake manifold defining an air passageway. The air intake heater includes a gasket having a conductor plate disposed between two non-conducting sealant layers, the conductor plate has at least one inner terminal adapted for positioning inside the air passageway and at least one outer terminal adapted for positioning outside the air passageway. A heating element is coupled to the gasket and adapted to be disposed within the air passageway, wherein the inner terminal is electrically coupled to the heating element and the outer terminal is electrically coupled to a power source.

Description:
RELATED APPLICATION 
     This is a utility patent application claiming the benefit of U.S. Provisional Application Ser. No. 60/117,750, filed Jan. 27, 1999. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to an electrical attachment for an electrically powered apparatus and, more particularly, to an electrically powered heater for use in an intake manifold of an internal combustion engine. 
     2. Discussion 
     Vehicles operating in colder climates are commonly equipped with a heater to warm the engine block or the air/fuel mixture entering the cylinders of an internal combustion engine. The air intake heating devices generally include a heating element disposed in the intake air passageway of an engine and electrically connected to a power source. Current is passed through the heating element to increase the temperature of the surrounding air as it passes the heating element and enters the combustion chamber of the engine. 
     With the advent of aerodynamic concerns and component weight reduction in an attempt to increase fuel economy, the engine compartment of motor vehicles has become a significant packaging challenge. Specifically, components buyers have been strongly urged by the vehicle manufacturers to create components which require less space and weigh less than their predecessors. In addition, the volume metric envelope in which the engine must package has been similarly reduced. In order to accomplish this task, the engine manufacturer has had to reduce the clearance between components such as the intake and the engine head. Accordingly, access to portions of the engine compartment may be limited. 
     In view of the above trends, a need exists for an air intake heater requiring a minimal amount of space outside of the engine components. In addition, a need exists for an air intake heater having an electrical attachment that originates inside of the intake manifold and is completed outside of the manifold. 
     SUMMARY OF THE INVENTION 
     The invention allows the termination of the air intake heater in a very confined space while optimizing heat transfer and minimizing air flow restrictions. More particularly, the grounding/sealing gasket of the present invention provides an electrical attachment that originates inside the manifold and is completed outside the manifold. 
     An air intake heater for use in a motor vehicle has an engine with an engine block and an intake manifold defining an air passageway. The air intake heater includes a gasket having a conductor plate disposed between two non-conducting sealant layers, the conductor plate has at least one inner terminal adapted for positioning inside the air passageway and at least one outer terminal adapted for positioning outside the air passageway. A heating element is coupled to the gasket and adapted to be disposed within the air passageway, wherein the inner terminal is electrically coupled to the heating element and the outer terminal is electrically coupled to a power source. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other advantages of the invention will become apparent to one skilled in the art upon reading the following specification, drawings and subjoined claims. 
     FIG. 1 is a perspective view of the grounding/sealing gasket of the present invention; 
     FIG. 2 is a perspective view of the grounding/sealing gasket coupled to an exemplary intake manifold; 
     FIG. 3 is a cross-sectional side view of the grounding/sealing gasket of the present invention; 
     FIG. 4 is an electrical schematic depicting a parallel and a series connection of multiple grounding/sealing gaskets; 
     FIG. 5 is a top view of a second embodiment of the grounding/sealing gasket of the present invention; 
     FIG. 6 is a side view of the grounding/sealing gasket shown in FIG. 5; 
     FIG. 7 is a top view of the second embodiment of the grounding/sealing gasket coupled to an exemplary heater; 
     FIG. 8 is a side view of the heater and gasket subassembly of FIG. 7 coupled to an exemplary intake manifold and engine block; 
     FIG. 9 is a top view of a grounding/sealing gasket including power cord supports; and 
     FIG. 10 is a side view of the grounding/sealing gasket of FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The invention described and illustrated herein is directed to an air heating device for use in an internal combustion engine. More particularly, the grounding/sealing gasket provides for mounting the air intake heater in a very confined space while optimizing heat transfer and minimizing air flow restrictions. More particularly, the grounding/sealing gasket of the present invention provides an electrical attachment that originates inside the manifold and is completed outside of the manifold. 
     With reference to the drawings, a grounding/sealing gasket constructed in accordance with the teachings of an embodiment of the present invention is generally identified at reference numeral  10 . The grounding/sealing gasket is shown operatively associated with an exemplary air intake heater  12 . 
     As particularly shown in FIG. 1, the grounding/sealing gasket is illustrated to generally include a plate-like body  14  having a first tab  16  and a second tab  18  integrally formed therewith. In a first embodiment of the present invention, the gasket  10  is adapted for insertion between an intake manifold  19  (FIG. 2) and a block (not shown) of an internal combustion engine. Accordingly, the air intake heater  12  is placed within an air passageway  21  defined by the intake manifold  19 . Furthermore, the gasket  10  provides a mechanical seal between the intake manifold  19  and the engine block as well as grounding of the air intake heater  12  such as to the intake manifold  19  as illustrated in FIG.  2 . 
     As best illustrated in the cross-sectional view of FIG. 3, the plate-like body  14  of the gasket  10  includes an electrical conductor plate  22  sandwiched by two non-conductive sealant layers  24 . The first tab  16  and the second tab  18  of the gasket  10  are not coated with sealant and may be electrically coupled to ground or to another heater as needed to satisfy the heating requirements of the particular application. 
     One skilled in the art will appreciate that the non-conductive sealant layers  24  act as cushions to take up any imperfections in the intake manifold  19  or the engine block. It should also be appreciated that silicone may be used as an insulator and a sealant in this application by vulcanizing the silicone to the plate-like body  14  or utilizing a pressure sensitive adhesive for attachment. Additionally, the sealant layer  24  may be supported with a fiberglass mesh for ease of handling and positioning on the plate-like body  14 . In general, supported silicone is more workable but does not provide the same degree of sealing as the unsupported silicone. Accordingly, the specific structural configuration of the sealant  24  will depend on the application requirement. 
     FIG. 4 illustrates a parallel and a serial connection of intake heaters  12  using the grounding/sealing gasket  10  of the present invention. In the parallel connection configuration, a first end  26  of a heating element  28  is connected to a power source  30  such as through a terminal  32  (FIG.  1 ). A second end  34  of the heating element  28  is electrically coupled to the first tab  16  of the gasket  10 . When energized, current passes through the terminal  32 , heating element  28  and into the conductor plate  22  of gasket  10  via the first tab  16 . The current, as best illustrated by arrows  36  in FIG. 1, proceeds bi-directionally through the conductor plate  22  to ground via the second tab  18 . 
     FIG. 4 also illustrates a series connection arrangement for the gasket  10  of the present invention. Specifically, as will be appreciated by those skilled in the art, an electrical connector  37  may be used to connect the second tab  18  of an upstream gasket to the terminal  32  of a downstream gasket to provide a serial connection of heater elements. In this manner, any number of grounding/sealant gaskets  10  may be electrically coupled in series to suit a specific application. 
     It should be appreciated that the conductor plate  22  is a current carrying member and as such, care must be taken to provide an appropriate cross-sectional area to deliver current while preventing undesirable self-heating. As shown in FIG. 1, a parallel path is provided as illustrated by arrows  36  thereby increasing the amount of current that the conductor plate  22  may transfer. However, in this configuration, it is preferred that the lengths of the respective parallel current paths remain the same to equalize the resistance within the paths and subsequently the self-heating within the conductor. 
     With the above concerns in mind, the preferred embodiment of the present invention includes a 0.060 inch thick conductor plate  22  for passing the current. Mechanical sealing and electrical insulation are provided by sealant layers  24  having a thickness of approximately 0.020 inches. The resulting 0.100 inch gasket height provides a suitable configuration for the application illustrated in FIG.  2 . However, those skilled in the art will appreciate that the specific configuration, including the conductor and sealant thicknesses as well as the specific configuration of the first tab  16  and the second tab  18  along with the conductor plate  22  itself, may be varied to satisfy application specific criterion. 
     It should further be appreciated that the interconnection of the grounding/sealing gasket  10  and the intake manifold  19  may be accomplished through a variety of mechanical connections generally known in the art. It is contemplated that the connection may be specifically accomplished through a bolt or welded stud connection at the second tab  18  via the use of fastener apertures  38 . It is further contemplated that the heating element  28  may be connected to the gasket  10  through a variety of techniques such as welding. 
     With reference to FIGS. 5-8, a second embodiment of the grounding/sealing gasket of the present invention is generally depicted to offer a drop-in style heater having both the power and ground terminals positioned outside of the engine. Accordingly, no modifications to the intake manifold or block are required. The second embodiment of the grounding/sealing gasket includes a gasket assembly  40  that achieves the previously mentioned goal by encapsulating a ground conductor  42  and a power conductor  44  within a non-conductive medium  46  as shown in FIG.  5 . The ground conductor  42  and the power conductor  44  are preferably constructed from an electrically conductive material such as galvanized steel or copper sheet. The metal conductors are supported in the non-conductive medium  46  such that the portions positioned between the intake manifold  19  and an engine block  47  (FIG. 8) are electrically insulated therefrom. The non-conductive medium  46  may be constructed from a thermoplastic, silicon, ceramic or fiberglass preferably injection molded about the ground conductor  42  and the power conductor  44  to create the grounding/sealing gasket  40 . One skilled in the art will appreciate that an additional sealant may be required to provide an air tight seal between the two surfaces of the gasket assembly  40  with the intake manifold  19  and the engine block  47 . If an additional sealant is required, methods known in the art such as providing a gasket, an O-ring, or pliable sealant are suitable for this purpose. 
     FIGS. 5 and 6 depict the power conductor  44  including an internal terminal  48  and an external terminal  50  protruding from the non-conductive medium  46 . In similar fashion, the ground conductor  42  includes an internal terminal  52  and an external terminal  54  extending therefrom. Each of the ground conductor and the power conductor also include a heater mounting flange  56 . In the preferred embodiment, the heater mounting flanges  56  are not used as electrical conductors but simply mechanical mounting means for the air intake heater  12 . Accordingly, the heater mounting flanges  56  are merely exemplary and a variety of other mounting schemes may be implemented without departing from the scope of the present invention. 
     Referring to FIGS. 7 and 8, the first end  26  of the heating element  28  is coupled to the internal terminal  48  of the power conductor  44 . Additionally, the second end  34  of the heating element  28  is electrically and mechanically coupled to the internal terminal  52  of the ground conductor  42 . In this manner, a circuit is constructed with current entering at the external terminal  50  of the power conductor, traveling through the heating element  28  and exiting through the external terminal  54  of the ground conductor  42 . 
     FIGS. 9 and 10 depict a further refinement of the gasket assembly  40  of the present invention including a pair of power cord supports  58  integrally formed with the ground conductor  42  and extending outwardly therefrom. In the preferred embodiment, the power cord supports are “P” shaped clamps for securing and supporting the wires coupled to the external terminals. Each of the clamps or supports  58  includes a looped band  60  defining an aperture  62  for receipt of a wire (not shown). The aperture  62  may be reduced in size by closing the loop such as via threaded fasteners (not shown). However, the specific configuration of the support  58  is merely exemplary and one skilled in the art should appreciate that other clamping or support mechanisms may be utilized without departing from the scope of the present invention. It should also be appreciated that each of the power cord supports  58  extend from the ground conductor  42  thereby eliminating the possibility of inadvertent short circuiting through contact of tools such as screwdrivers and the like. 
     In view of the above description of the present invention, it should be appreciated that the grounding/sealing gasket of the present invention facilitates attachment of an intake air heater within the air passageway of the manifold in situations where space constraints prohibit conventional mounting. The mechanical sealing and electrical insulation of the conductor plate  22  by sealant layers  24  effectively manages current and air flow for proper operation of the heater. 
     The foregoing discussion discloses and describes merely exemplary embodiments of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims, that various changes, modifications and variations may be made therein without department from the spirit and scope of the invention as defined in the following claims.