Abstract:
An apparatus is provided for dissipating an electrostatic charge from a vehicle seat and from an occupant seated thereon, wherein a blower directs ionized air through a vent toward the seat and occupant to neutralize an electrostatic charge accumulated on the surface and occupant. A sensor is configured to detect when the occupant is separating from the vehicle seat, and to activate the ionizer in response thereto. The apparatus also includes a seat cooling system for directing cool air through the seat, wherein a blower directs ionized air through vent holes in the seat when the cooling system is operating. A method is also provided for dissipating an electrostatic charge from a vehicle seat and an occupant seated thereon, including generating ionized air, sensing separation of a passenger from the seat, and directing ionized air toward the seat and occupant through one or more vents to dissipate the static charge.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to a system and method for neutralizing or dissipating an electrostatic charge from a surface of a vehicle seat and an occupant of the seat using a sufficient amount of ionized air to thereby minimize an electrostatic discharge between an exiting occupant and the vehicle. 
       BACKGROUND OF THE INVENTION 
       [0002]    Electrostatic discharge (ESD) is the rapid transfer of an accumulated electrostatic charge resulting from proximate or direct contact between two bodies or objects having different electric potentials. The severity of an ESD event may be influenced or affected by a number of environmental and/or physical factors, including the composition of various materials of construction, relative motion of the two bodies, low atmospheric humidity, and/or improper or inadequate grounding. Negative and positive charges are created on the surfaces of the two bodies when the bodies are separated. These charges are then effectively neutralized as the charges seek a grounding path. Thus, ESD occurs when a charged body or object comes in proximity to a conductive material offering an efficient path to ground. Various ESD control devices therefore exist for the purpose of reducing the potential for static build-up and/or to provide an alternate grounding path for harmlessly dissipating any built-up electrostatic charge, or for discharging an electrostatic charge well before a substantial amount of charge may build. Such devices may include grounding straps, ESD-prevention smocks or other anti-ESD clothing, and humidifiers. 
         [0003]    As it relates to automotive vehicles, an ESD event is most commonly experienced as an instantaneous discharge that results when a vehicle passenger or occupant touches a door handle or other metal component upon exiting the vehicle. Various devices exist for controlling the effects of ESD in automotive vehicles, with varying effectiveness. For example, conductive tires or grounding straps attached to the underside of the vehicle frame may be used to dissipate a static charge from the vehicle. However, these devices may be less than optimal due to wear of the device, such as may occur when dragging a grounding strap on the pavement, as well as added cost, inconvenience, and/or unattractive appearance of such devices. Additionally, such grounding devices may be relatively ineffective in grounding an occupant due to the inability of the seat surface, i.e. the interface between the seat and the occupant, to provide an efficient conductive path to the grounding devices. 
       SUMMARY OF THE INVENTION 
       [0004]    Accordingly, an apparatus is provided for dissipating an electrostatic charge from a surface of a vehicle seat and an occupant seated on the surface. The apparatus includes an ionizer for ionizing a supply of air and a blower for directing the ionized air toward the surface to neutralize or dissipate an accumulated electrostatic charge on the occupant and surface. 
         [0005]    In one aspect of the invention, the blower directs the ionized air toward the surface through a vent positioned external to the seat, such as a heating, ventilation, and air conditioning (HVAC) blower vent positioned on a door, console, or instrument panel. 
         [0006]    In another aspect of the invention, a sensor is configured to detect when the occupant is separating from the vehicle seat, with the blower directing the ionized air at the surface when separation is detected by the sensor. 
         [0007]    In another aspect of the invention, the apparatus includes a seat cooling system having a perforated vent positioned within the vehicle seat, with the blower directing the ionized air at the seat surface through the perforated vent. 
         [0008]    In another aspect of the invention, the perforated vent is sufficiently positioned to function as the seating surface. 
         [0009]    In another aspect of the invention, a method is provided for dissipating an electrostatic charge from a vehicle occupant and a vehicle seat, including generating a supply of ionized air, sensing separation of the occupant from the surface, and directing ionized air at the surface to dissipate the electrostatic charge. 
         [0010]    In another aspect of the invention, the method includes passing ionized air through a vent positioned external to the vehicle seat. 
         [0011]    In another aspect of the invention, the method includes equipping the vehicle seat with a seat cooling system having a vent for directing a supply of cool air through the seat to cool the occupant, the ionized air being an ionized portion of the cool air. 
         [0012]    The above objects, features and advantages, and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a fragmentary schematic cutaway side view of a vehicle having a static-reducing ionizing blower system according to the invention; 
           [0014]      FIG. 2  is a fragmentary perspective side view of a portion of a passenger compartment of a vehicle having the static-reducing ionizing blower system of  FIG. 1 ; and 
           [0015]      FIG. 3  is a perspective side view of a vehicle seat in phantom to show a cooling system and ionizing blower according to the invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    Referring to  FIG. 1 , wherein like reference numbers correspond to like or similar components throughout the several figures, a vehicle  10  is shown having a vehicle interior or passenger compartment  11 . A floor pan or floor  15  spans the passenger compartment  11  and supports a vehicle seat  14  that faces a console or instrument panel  21  and is configured to carry a driver, passenger, or other occupant  26  of vehicle  10 . The vehicle seat  14  has a seat cushion  18  with a seating surface  16 , i.e., the surface of the vehicle seat  14  having the most direct and sustained contact with the occupant  26 , with the vehicle seat  14  being upholstered or covered in an aesthetically pleasing manner, such as with leather or a suitable fabric upholstery (not shown), and mounted or fastened to a suitable seat base or frame  32 . The seat  14  is preferably variably repositionable with respect to the floor  15  in response to readily accessible occupant-selectable seat controls  38 , such as a power or manual seat height and position adjuster and/or seat recliner mechanism, switch, and/or lever adapted to move or reposition the seat  14  forward and rearward as desired within the passenger compartment  11 , as represented by arrows A, as well as recline and incline the seat  14 , as represented by arrows B, to thereby adjust for various seat position preferences of different occupants  26 . 
         [0017]    As an occupant  26  operates or drives the vehicle  10 , the separation and movement of electrically charged air and dust particles in close proximity to the outer surfaces of the vehicle  10  may act to impart a static charge to the vehicle  10 . Additionally, in exiting or alighting from the vehicle  10 , the movement and separation of an occupant  26  relative to the vehicle seat  14  is often sufficient to generate an accumulated charge on the seating surface  16  and/or on the occupant  26 . Then, as the occupant  26  touches the vehicle  10  upon exiting, particularly when touching a conductive vehicle component such as a metal door or door handle (not shown), the electrostatic charge carried by the occupant  26  may rapidly discharge or transfer back to the vehicle  10 . 
         [0018]    Therefore, to help minimize such an electrostatic discharge or ESD event, the vehicle seat  14  is equipped or configured with a sensor  13  suitably configured for detecting the separation of an occupant  26  from the vehicle seat  14 , and for communicating this event to a controller  60  to thereby activate or initiate an air ionization device or ionizer  28 , as will be described in more detail hereinbelow. The sensor  13  is placed within the seat cushion  18  at or below the seating surface  16 , preferably at a depth sufficient to allow proper function of the sensor  13  without adversely affecting the comfort of the vehicle seat  14 . Sensor  13  may be a pressure transducer or other suitable pressure-sensitive device configured to detect the relieving or removal of a substantial amount of weight from the vehicle seat  14 , such as would occur when an occupant  26  exits the vehicle  10 . Alternately, other sensors may be used along with or in place of sensor  13 , such as infrared or heat-sensitive sensors (not shown), and/or other types of sensors suitable for detecting the presence of an occupant  26  in the vehicle seat  14 . 
         [0019]    The controller  60  is in electrical communication with sensor  13  and preferably also with a heating, ventilation, and air conditioning (HVAC) system  25 . The HVAC system  25  includes an air ionization system or ionizer  28 , a fan or blower  51 , an air conditioning unit  52 , and a heating system or heater  53 , with the HVAC system  25  being selectively controllable by an occupant  26  using an HVAC control panel  56  (see  FIG. 2 ) that is centrally or accessibly positioned on the instrument panel  21 . The ionizer  28  is operatively attached to or formed integrally with the fan or blower  51 , with the blower  51  having a motorized internal fan (not shown) or other similar electromechanical device operable for circulating or moving air drawn through an air intake  61  through the HVAC system  25  and into the passenger compartment  11 , as determined by the selected settings on the HVAC control panel  56 . Alternately, the ionizer  28  and blower  51  may be separate from the HVAC system  25  to facilitate placement of the ionizer  28  and blower  51  in proximity to the point of use, as will be described in more detail later hereinbelow. The ionizer  28  likewise is preferably activated by the occupant  26  using the HVAC control panel  56  or a separate device (not shown), so that the HVAC system  25  may be operated with or without also operating the ionizer  28 , depending on the personal preference of the occupant  26 . 
         [0020]    As will be understood by those of ordinary skill in the art, ionizer  28 , whether integrated with the blower  51  or operating as a separate device, is any mechanism capable of electrically charging air molecules, generally by exposing air to a high voltage. Ionizer  28  may be designed to generate specifically charged ions, i.e. exclusively positively or negatively charged ions, or to randomly or indiscriminately generate a combination of both positive and negative ions as needed, depending on design requirements. Various methods are available to ionize air so that the air may thereby conduct an electric charge. For example, an air stream may be subjected to controlled sparking or arcing, or preferably, air may be ionized by using AC, steady-state DC, or pulse-DC ionization methods. 
         [0021]    By ionizing air, the ionizer  28  may provide air molecules with the ability to carry an electrical charge. Air molecules may come from an available air stream, such as provided or generated by HVAC system  25 , or alternately from an air stream that is separately generated outside of HVAC system  25 . When the charged or ionized air stream is directed toward charged surfaces within the passenger compartment  11 , such as the seating surface  16  of the vehicle seat  14  in accordance with the invention, an electrostatic charge resident on and/or between the occupant  26  and seating surface  16  is effectively neutralized. As a result, the effect of any ESD event experienced by an occupant  26  upon exiting the vehicle  10  is minimized. 
         [0022]    Turning now to  FIG. 2 , the passenger compartment  11  is shown in greater detail having a vehicle seat  14  with a seat cushion  18  supported by a frame  32 , as described hereinabove. The seat cushion  18  has a seating surface  16 , under which is positioned the sensor  13 , also as previously described hereinabove. A door  65  is adjacent to the vehicle seat  14 , and includes an HVAC opening or vent  20  that is in fluid communication with or otherwise connected to the HVAC system  25  (see  FIG. 1 ), such as through a pipe, duct  23 , or other suitable conduit. A console  71  is positioned between two seats, such as vehicle seat  14  and a substantially similar passenger-side seat (not shown) and/or between two rear seats (not shown), and may include, for example, compact disc (CD) holders, coin holders, cupholders, and/or an armrest. As shown, the console  71  is integral with and flows into the instrument panel  21 , but may also stand alone as a separate component within the scope of the invention. Although only a portion of console  71  is shown in  FIG. 2  so as to more clearly show vehicle seat  14 , console  71  preferably also includes a vent  20  (not shown) in the rear of the console  71  facing a rear or back seat (not shown), and connected with HVAC system  25  as described hereinabove, so as to deliver ionized air to a rear passenger seat (not shown). 
         [0023]    As shown in phantom, an ionizer  228  and blower  251  may also be positioned within a duct  23  apart from the HVAC system  25  and in proximity to the vent  20 , such that the ionizer  228  and blower  251  are operable for generating and/or circulating its own ionized air in response to controller  60  and sensor  13  as described hereinabove, without requiring electrical communication with the HVAC system  25 . Additionally, a substantially similar HVAC opening or vent  22  is positioned on or within instrument panel  21 , along with an alternate ionizer  228  and blower  251  as previously described hereinabove. The HVAC control panel  56  is preferably positioned within accessible reach of an occupant  26  (see  FIG. 1 ) seated in the vehicle seat  14 . While the vehicle seat  14  as shown in  FIG. 2  is a driver-side seat positioned facing a steering wheel  17  and steering column  19 , any vehicle seat  14  within the passenger compartment  11  may be similarly configured in accordance with the invention, for example a passenger-side seat or rear seat (not shown). 
         [0024]    When the ionizer  28  is activated, and upon detection by sensor  13  of the separation of an occupant  26  from the vehicle seat  14 , a portion of air from the HVAC system  25  is diverted to the ionizer  28 . Alternately, when the ionizer  228  is activated, air is directed to the ionizer  228  by blower  251 . A sufficient portion or amount of ionized air, represented by arrows C in  FIG. 2 , is then directed by vent  20  across the seat cushion surface  16  of the vehicle seat  14 . Likewise, ionized air, represented by arrows D, is directed by vent  22  on instrument panel  21  across and/or at seating surface  16 , with the vents  20  and  22  preferably being simultaneously operable so as to maximize the concentration of ions dispersed by the vents  20 ,  22  into proximity with the vehicle seat  14 . Alternately, the ionizer  28  may be activated and continuously operable whenever the HVAC system  25  is in operation, while an occupant  26  remains seated and without regard to the operation of sensor  13 . However, selective activation of the ionizer  28 / 228  is preferred, so as to allow an occupant  26  to decide when additional ESD protection is desired, such as during dry weather conditions, while allowing the occupant  26  to turn the ionizer  28 / 228  off during humid or otherwise low-ESD weather conditions. 
         [0025]    Turning now to  FIG. 3 , a second embodiment of the invention is shown as a vehicle seat  14  configured with a seat cooling device in which a seat cooling duct  54  delivers cool air, represented by arrow E, from a seat cooling unit  68  positioned at a suitable location within the seat  14 , such as under the seat cushion  18 . The cool air (arrow E) is preferably generated within the seat cooling unit  68 , for example by using an internal fan or blower  351  or other suitable device, and then channeled or routed through an upper opening  40  in the seat cooling unit  68  and through the seat cooling duct  54 . An ionizer  328  is likewise positioned within the seat  14  and is operable for generating a supply of ionized air in response to sensor  13 , as previously described hereinabove with reference to ionizer  28 / 228  (see  FIG. 1 ). A seat vent  30  is positioned within the vehicle seat  14  under the seating surface  16 , or alternately configured to function as the seating surface  16 , and preferably takes the form of a perforated trim insert or other suitable component having a plurality of orifices or holes  33  for dispersing the cool air (arrow E) into numerous, smaller air streams, as represented by the arrows F. Seat cooling unit  68  may be operated in conjunction with ionizer  328  when the ionizer  328  is activated, or alternately may be operated independently of the ionizer  328 , with ionized air (arrows F) being delivered to the seating surface  16  when the ionizer  328  is activated by the sensor  13 , thereby taking advantage of any existing holes  33  already used in conjunction with a seat cooling system. 
         [0026]    While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.