Patent Publication Number: US-8530792-B2

Title: Heated side window glass

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation-in-part of U.S. patent application Ser. No. 10/644,345 filed on Aug. 20, 2003. The disclosure of the above application is incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to side window glass and, more particularly, relates to side window glass having a portion thereof electrically heated. 
     BACKGROUND OF THE INVENTION 
     The advantages of defogging and de-icing the windows of a vehicle have long been recognized for purposes of improving vehicle safety during inclement weather. However, unfortunately many systems used today to defog and de-ice windows of the vehicle, particularly side windows, require the vehicle&#39;s engine to first achieve a sufficient operating temperature. More specifically, many known systems used today to heat side windows employ a defrosting vent positioned adjacent a forward portion of the side window. This defrosting vent provides warm air blowing across the interior face of the side window to heat the side window. However, these systems are very inefficient when considering the time necessary to achieve sufficient heat. The warm air is a product of the vehicle&#39;s heating system, which only operates once the vehicle engine has achieved at least a minimum operating temperature. As many drivers know, modern automobile engines may require an extended amount of time to achieve this minimum operating temperature. Accordingly, attempts have been made to provide a means of directly heating side windows of a vehicle which results in applying immediate and direct heat to the window surface when desired. 
     U.S. Pat. No. 5,466,911, issued to Spagnoli et al., discloses an electrically heated window assembly by producing a concentration of heat at the portion of the front window through which a driver views an exterior mirror. This concentration of heat is produced by providing a pair of bus bars, positioned on opposing ends of the window, and a transparent conductive film positioned between the pair of bus bars. During operation, electricity flows from one bus bar to the other bus bar through the transparent conductive film, thereby producing heat within the film to heat the window. 
     However, the Spagnoli et al. system suffers from a number of significant disadvantages. By way of non-limiting example, the transparent conductive film is particularly susceptible to damage as it extends across the entire interior surface of the window. Such damage may include scrapes and/or gouges along the surface, peeling of the conductive film, or even failure of particular heating sections due to severing of the conductive film. Moreover, the Spagnoli et al. system may not minimize manufacturing costs as it includes a complicated, multi-part configuration requiring the application of bus bars, transparent conductive film, non-conductive breaks, temperature sensors, and the like. 
     U.S. Pat. No. 4,410,843, issued to Sauer et al., discloses an electrically controlled sliding window and proximity detector which includes a window heating system. The Sauer et al. system uses heat generated by current flowing through a series of horizontal, parallel conductors positioned generally in the upper half of the window. The series of conductors electrically interconnect a pair of bus bars, which extend along the forward and rearward edges of the window glass within view of the operator. During operation, current flows from a current source from one bus bar to the other bus bar through the conductors, which generate heat to heat the upper portion of the side window. 
     However, the Sauer et al. system suffers from a number of significant disadvantages. For example, the Sauer et al. system fails to directly heat the portion of the side window through which the operator views the exterior side view mirror. The Sauer et al. system heats the top portion of the side window, yet does not heat the portion of the side window adjacent the side view mirror. In fact, the lowest portion of the heated region of the Sauer et al. system generates the least amount of heat due to the increased length of the conductor relative to the other conductors. This increase length of the conductor produces a higher resistance in the conductor wire, thereby limiting current flow relative to the shorter conductors. Accordingly, in operation, the Sauer et al. system will first defog and/or de-ice the top of the side window and, thus, the operator must still wait for sufficient heat to build up to defog and/or de-ice the lower section of the heated region. 
     Accordingly, there exists a need in the relevant art to provide a side window glass having a heated region positioned generally within a line of sight of side view mirror. Furthermore, there exists a need in the relevant art to provide a heated side window glass that is simple in design and provides concentrated direct heating solely at the line of sight region of the glass. Still further, there exists a need in the relevant art to provide a heated side window glass that does not suffer from the disadvantages of the prior art. 
     SUMMARY OF THE INVENTION 
     According to the principles of the present invention, a heated side window assembly for an automobile having an advantageous construction is provided. The automobile includes a sideview mirror mounted generally adjacent the heated side window assembly. The heated side window assembly includes a glass sheet having an interior surface and an exterior surface and a single, continuous, electrical conductor strip mounted to the interior surface of the glass sheet. The conductor strip outputs radiant heat in response to an electrical current flow therethrough. The conductor strip is positioned such that it generally bounds, but does not enter, an area defined by an operator&#39;s line of sight to the sideview mirror of the vehicle. A pair of conductor pads is electrically coupled to the ends of the conductor strip. A switch is provided for selectively outputting a control signal and a controller is electrically coupled between a power supply and the pair of conductor pads. The controller provides electrical current to the conductor strip in response to the control signal so as to heat the area of the glass sheet generally adjacent to the sideview mirror. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG. 1  is a side view of a heated side window assembly according to a first embodiment of the present invention; 
         FIG. 2  is an enlarged perspective view of a connector bracket for securing electrical lines to electrically conductive strips; 
         FIG. 3  is a side view of a heated side window assembly according to a second embodiment of the present invention; 
         FIG. 4  is a side view of a heated side window assembly according to a third embodiment of the present invention; 
         FIG. 5  is a perspective view illustrating the sight lines relative to a first visual reference point; and 
         FIG. 6  is a perspective view illustrating the sight lines relative to a second visual reference point. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring to the  FIG. 1 , a heated side window assembly  10  according to a first embodiment is illustrated having a side window (sidelite) glass  12  adapted to be slidably mounted in a front door (not shown) of a vehicle. Sidelite glass  12  may have any shape depending on the specific vehicle configuration. It should be understood that the specific sidelite glass shape described herein is merely for illustrative purposes. It should also be understood that sidelite glass  12  may be a laminated sidelite and, thus, portions of the present invention may be disposed between layers of such laminated sidelite. 
     Sidelite glass  12  of the present embodiment includes a front edge  14 , an inclined edge  16 , a top edge  18 , a rear edge  20 , and a bottom edge  22 . Sidelite glass  12  is shaped to be slidably received within a window opening (not shown) of the vehicle door. Sidelite glass  12  further includes a pair of apertures  24  for mounting a window operating mechanism bracket (not shown) adjacent bottom edge  22  to aid in the automatic or manual raising and lowering of sidelite glass  12 . As will be discussed herein, alternative sidelite glass shapes may be used, which may effect the shape of any heating system. The shape of sidelite glass  12  is also dependent upon the shape and angle of the vehicle A-pillar, which may effect the relative size and shape of front edge  14  and inclined edge  16 . 
     A sideview mirror  26  is illustrated for use with heated side window assembly  10 . Sideview mirror  26  is of conventional design and is mounted to at least one of the front doors of the vehicle. A nominal cover line  28  is shown which illustrates an edge of a shroud plate used for securely mounting sideview mirror  26  to the vehicle. During operation of the vehicle, an operator views sideview mirror  26  through a line of sight region  30  of sidelite glass  12 . Line of sight region  30  of sidelite glass  12  is generally positioned adjacent sideview mirror  26  and within the line of sight between the operator and sideview mirror  26 . Line of sight region  30  is preferably the area in which defogging and/or de-icing occurs during operation. Determination of the size, shape, and position of line of sight region  30  will be further discussed herein. 
     In the present embodiment, heated side window assembly  10  further includes a heating system  32  for heating line of sight region  30  of sidelite glass  12  without in any way obscuring line of sight region  30 . Heating system  32  includes one or more conductor strips  34 , a pair of conductor pads  36 , a controller  38 , and a power supply  40 . Conductor strips  34  are preferably electrically conductive strips mounted to the interior surface of sidelite glass  12  or laminated within sidelite glass  12 . In a first embodiment, conductor strips  34  are generally square-shaped such that it includes a first leg  42 , a first lower strip  44 , a rear strip  46 , a top strip  48 , a front strip  50 , a second lower strip  52 , and a second leg  54 , which are interconnected to provide a continuous current path between first leg  42  and second leg  54 . Conductor strips  34  are preferably sized so as to extend generally about the periphery of line of sight region  30  of sidelite glass  12 . That is, conductor strips  34  are preferably sized to be generally outside of the direct line of sight to sideview mirror  26  for a range of vehicle operator sizes and head positions (as will be discussed herein). This arrangement thus minimizes or eliminates any visible obstructions between the operator and sideview mirror  26 . Conductor strips  34  are preferably covered with electrically insulating enamel to protect the strips from corrosion and wear and tear. Conductor strips  34  may be installed on the interior surface of sidelite glass  12  via known silk-screening techniques. 
     In some embodiments, conductor strips  34  have varying cross-sectional area along its length that can be used to control the amount of localized electrical resistance. In areas that a higher heat output is desired, the cross-sectional area of one or more conductor strips  34  can be reduced to increase the localized resistance and, thus, increase the localized heat output. This arrangement permits a custom tailoring of the heat output within line of sight region  30  to maximize the desired heating in any one or more discrete areas within line of sight region  30 . 
     Conductor strips  34  each terminates into one of the pair of conductor pads  36  in parallel relationship to provide electrical communication therebetween. The pair of conductor pads  36  are each made of an electrically conductive material. As can be seen in  FIG. 1 , the pair of conductor pads  36  are each positioned below a door or beltline  56 , which schematically represents the lowermost boundary of sidelite glass  12  that is exposed to view when sidelite glass  12  is in a raised position. Accordingly, it should be appreciated that the pair of conductor pads  36  is concealed from sight for improved aesthetic quality. 
     Each of the pair of conductor pads  36  is electrically coupled to controller  38  via a pair of lines  58 , such as flexible wires. The pair of lines  58  is sized to maintain electrical communication between controller  38  and the pair of conductor pads  36  during operation of sidelite glass  12 . That is, the present invention, unlike previous known designs, permits operation of heating system  32  in every position of sidelite glass  12  because electrical communication is maintained between controller  38  and the pair of conductor pads  36 . This arrangement has the benefit of permitting a vehicle operator to lower sidelite glass  12  into a position that allows for ventilation of the passenger cabin, without interfering or otherwise impeding with operation of heating system  32 . 
     As seen in  FIG. 2 , each conductor pad  36  may be a connector bracket  100  having a pair of downwardly extending footpads  102  bonded or otherwise fastened to sidelite glass  12  via a conventional conductive fastening material  103 . Connector bracket  100  further includes a spanning portion  104  extending between the pair of downwardly extending footpads  102  and a male portion  106  extending upwardly from spanning portion  104 . A female electrical connector  108  can be used to electrically and mechanically couple lines  58  to male portion  106 . To ensure reliable operation, lines  58  can be fastened or otherwise held relative to sidelite glass  12  at a position that is spaced apart from conductor pads  36 , such as at points  110  ( FIG. 1 ), to relieve any physical strain or stress on conductor pads  36 . 
     Controller  38  may be a separate controller or, more preferably, is incorporated within the main controller of the vehicle. Controller  38  is activated by the operator of the vehicle using a switch  60 . Switch  60  is of conventional design and is mounted within the passenger compartment of the vehicle. Alternatively, switch  60  may be replaced or at least supplemented by an automatic switching mechanism that activates or deactivates heating system  32  in response to expiration of a predetermined time, detection of a predetermined moisture content, etc. Controller  38  is electrically coupled to power supply  40  of the vehicle. Power supply  40  may be either the battery or alternator of the vehicle. Power supply  40  is the current source for heating system  32 . 
     Preferably, line of sight region  30  is generally positioned adjacent sideview mirror  26  and within the line of sight between the operator and sideview mirror  26 . To this end, it is most preferable to determine this line of sight region  30  through three-dimensional modeling. Firstly, it should be understood that most modern vehicles are designed for a given range of occupant sizes and, thus, the general range of spine positions within the passenger compartment of the vehicle is also generally known. This spine position helps provide a range of eye positions from which to establish an eye reference range. Furthermore, the positioning of sideview mirror  26  further establishes the boundaries of the mirror. Hence, through the use of three-dimensional modeling, the various permutations may be calculated to define line of sight region  30 . Ideally, conductor strips  34  are positioned about line of sight region  30 , without obstructing line of sight region  30 , to provide the necessary direct heating of sidelite glass  12 . 
     In other embodiments, as seen in  FIG. 5 , line of sight region  30  is defined based on one or more seating positions in the vehicle and one or more human body sizes and positions. To this end, human body sizes and positions are based upon, at least in part, such parameters as torso size and position and seat back (or torso) angle. These parameters may be determined by a particular manufacturer and/or developed in connection with various worldwide standards, such as but not limited to the ECE R43 standards or equivalent standards. By way of example, with reference to  FIG. 5 , the overall size of line of sight region  30  can be defined by a first line of sight region LOS 1  and a second line of sight region LOS 2 . In some embodiments, line of sight region  30  can encompass the entirety of both first line of sight region LOS 1  and second line of sight region LOS 2 . First line of sight region LOS 1  can be defined through analysis of a first driver size and position. Similarly, second line of sight region LOS 2  can also be defined through analysis of a second driver size and position, where the second driver has a head position different than the first driver. 
     In this regard, first line of sight region LOS 1  is measured through the use of both horizontal and vertical planes extending at predetermined angles from a first visual reference point V 1 . This first visual reference point V 1  can be any desired reference point or, more likely, can represent an eye point location for a first driver, such as a 95 th  percentile male, in a driving position. An upper boundary of first line of sight region LOS 1  is defined by a first horizontal plane passing from first visual reference point V 1  downward at a predetermined angle, α 1 (V 1 ), measured in the X-Z plane. It has been found that an angle α 1 (V 1 ) in the range of about 0° to 20° below horizontal and, more particularly, 10° below horizontal can be used. A lower boundary of first line of sight region LOS 1  is defined by a second horizontal plane passing from first visual reference point V 1  downward at a predetermined angle, α 2 (V 1 ), measured in the X-Z plane. It has been found that an angle α 2 (V 1 ) in the range of about 11° to 31° below horizontal and, more particularly, 21° below horizontal can be used. It should be understood that angles α 1 (V 1 ) and α 2 (V 1 ) represent the angles the first driver must look up or down relative to horizontal to view the boundaries of sideview mirror  26 . 
     A forward boundary of first line of sight region LOS 1  is defined by a first vertical plane passing from first visual reference point V 1  to the left (in left-seat driver positions; or to the right, in right seat driver positions) at a predetermined angle, β 1 (V 1 ), measured in the X-Y plane. It has been found that an angle β 1 (V 1 ) in the range of about 17° to 47° relative to straight forward sight and, more particularly, 32° relative to straight forward sight can be used. A rearward boundary of first line of sight region LOS 1  is defined by a second vertical plane passing from first visual reference point V 1  to the left at a predetermined angle, β 2 (V 1 ), measured in the X-Y plane. It has been found that an angle β 2 (V 1 ) in the range of about 30° to 60° relative to straight forward sight and, more particularly, 45° relative to straight forward sight can be used. It should be understood that angles β 1 (V 1 ) and β 2 (V 1 ) represent the angles the first driver must look to the left (or right as noted above) to view the boundaries of sideview mirror  26 . Accordingly, the boundaries of first line of sight region LOS 1  can be defined. 
     As seen in  FIG. 6 , a similar method is used to define second line of sight region LOS 2  relative to a second visual reference point V 2 . This second visual reference point V 2  can be any desired reference point or, more likely, can represent an eye point location for a second driver, such as a 5 th  percentile female, in a driving position. As seen in  FIG. 6 , second visual reference point V 2  can be, in some embodiments, slightly lower in the Z-axis, as referenced by ΔZ, and slightly forward in the X-axis, as referenced by ΔX, relative to first visual reference point V 1 . In light of most conventional vehicle seat tracks, there will be little to no lateral movement between first visual reference point V 1  and second visual reference point V 2  (i.e. no appreciable ΔY). As seen in  FIGS. 5 and 6 , due to variations in size and position of the first driver and the second driver, first line of sight region LOS 1  and second line of sight region LOS 2  may be shifted relative to each other. 
     An upper boundary of second line of sight region LOS 2  is defined by a third horizontal plane passing from second visual reference point V 2  downward at a predetermined angle, α 3 (V 2 ), measured in the X-Z plane. It has been found that an angle α 3 (V 2 ) in the range of about 5° above to 15° below horizontal and, more particularly, 5° below horizontal can be used. A lower boundary of second line of sight region LOS 2  is defined by a fourth horizontal plane passing from second visual reference point V 2  downward at a predetermined angle, α 4 (V 2 ), measured in the X-Z plane. It has been found that an angle α 4 (V 2 ) in the range of about 6° to 26° below horizontal and, more particularly, 16° below horizontal can be used. It should be understood that angles α 3 (V 2 ) and α 4 (V 2 ) represent the angles the second driver must look up or down relative to horizontal to view the boundaries of sideview mirror  26 . 
     An forward boundary of second line of sight region LOS 2  is defined by a third vertical plane passing from second visual reference point V 2  to the left (in left-seat driver positions; or to the right, in right seat driver positions) at a predetermined angle, β 3 (V 2 ), measured in the X-Y plane. It has been found that an angle β 3 (V 2 ) in the range of about 27° to 57° relative to straight forward sight and, more particularly, 42° relative to straight forward sight can be used. A rearward boundary of second line of sight region LOS 2  is defined by a fourth vertical plane passing from second visual reference point V 2  to the left at a predetermined angle, β 4 (V 2 ), measured in the X-Y plane. It has been found that an angle β 4 (V 2 ) in the range of about 40° to 70° relative to straight forward sight and, more particularly, 55° relative to straight forward sight can be used. It should be understood that angles β 3 (V 2 ) and β 4 (V 2 ) represent the angles the second driver must look to the left (or right as noted above) to view the boundaries of sideview mirror  26 . Accordingly, the boundaries of second line of sight region LOS 2  can be defined. 
     To ensure that conductor pad  36  does not substantially obscure the driver&#39;s line of sight to sideview mirror  26 , it is desirable that conductor pad  36  remain outside of both first line of sight region LOS 1  and second line of sight region LOS 2 . This combined areas encompassing both first line of sight region LOS 1  and second line of sight region LOS 2  is bounded by A-Zone lines, as seen in  FIGS. 3-6 . 
     With continued reference to  FIGS. 3 and 4 , additional embodiments of heating system  32  are provided that illustrate various configurations of conductor strips  34 . For example, as seen in  FIG. 3 , heating system  32  may include a pair of conductor strips  34  arranged in a generally circular orientation. In this arrangement, the pair of conductor strips  34  may have a generally uniform cross-sectional area to maintain a generally consistent resistance along the length of conductor strips  34  resulting in generally consistent heating. However, this should not be regarded as the only permissible cross-sectional area configuration as other factors, such as various inherent glass properties and/or exterior cooling conditions (such as wind patterns), may warrant customizing the localized heating pattern as discussed above. 
     As seen in  FIG. 4 , heating system  32  may include three conductor strips  34  arranged in a generally trapezoidal orientation, having an inclined leg portion  112  generally parallel to inclined edge  16 . As described above, the orientation of conductor strips  34  may be chosen in concert with the cross-sectional area of conductor strips  34  to result in a predetermined heating pattern within line of sight region  30  to clear the area within A-zone of moisture in the most expeditious manner. 
     The specific orientation and cross-sectional area of conductor strips  34  can be chosen also in concert with number of conductor strips  34  and the electrical power available to run heating system  32 . As it should be appreciated, available power is finite in automobile applications because additional power would necessitate larger automotive electrical systems, which in turn would add additional load to the engine and reduce overall fuel efficiency. Therefore, the present invention enables electrical power to be efficiently used to produce rapid heat in a location where it is most needed, namely the line of sight region  30 , without wasting electrical power to heat secondary areas on sidelite glass  12 . In this regard, electrical power consumption can be reduced, or at least maintained, while simultaneously providing increased localized heating without obscuring the operator&#39;s vision to the sideview mirror  26 . 
     During operation, controller  38  receives a control signal from switch  60  in response to an input by the operator, detection of moisture, etc. Controller  38  then opens an electrical circuit extending between power supply  40  and the pair of lines  58 . Current then flows from power supply  40  through controller  38 , a first of the pair of lines  58 , a first of the pair of conductor pads  36 , through one or more conductor strips  34 , the other of the pair of conductor pads  36 , the other of the pair of lines  58 , controller  38 , and back to power supply  40  to define a current path. As current flows through the current path, resistance inherent in conductor strips  34  causes heat to be generated. This heat radiates generally about each strip to heat line of sight region  30  of sidelite glass  12 , to warm sidelite glass  12 , thereby producing a defogging and/or de-icing effect solely within the vicinity of heating line of sight region  30 . It should be noted that this is accomplished without obscuring line of sight region  30 . 
     It should be understood that due to the relative simplicity of heating system  32 , it is anticipated that each of the components, including conductor strips  34  and the pair of conductor pads  36 , may be made for after-market installation. That is, it is anticipated that conductor strips  34  and the pair of conductor pads  36  may be made of an electrically conductive material having an activatable adhesive applied thereto. An after-market installer could simply adhere conductor strips  34  and the pair of conductor pads  36  to a preferred location on the sidelites of the vehicle. Controller  38  and switch  60  may be mounted within the vehicle and coupled to an existing vehicle power supply. Controller  38  may then be electrically coupled to the pair of conductor pads via a pair of lines extending through the vehicle door hinge. Therefore, the present invention may find utility in retrofitting late model vehicles or those existing vehicles that are frequently exposed to fogging and/or icing conditions, such as in northern locations. 
     As can be appreciated from the foregoing discussion, heating system  32  of the present invention efficiently and economically provides direct, instantaneous heating of the portion of the sidelite glass that is within the operator&#39;s line of sight with sideview mirror  26 . 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.