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.
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.
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.
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.
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.
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.
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.
In another aspect of the invention, the perforated vent is sufficiently positioned to function as the seating surface.
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.
In another aspect of the invention, the method includes passing ionized air through a vent positioned external to the vehicle seat.
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.
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.
Referring to
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.
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.
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
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.
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.
Turning now to
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
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
Turning now to
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.