Abstract:
A contamination cleaner for a socket of a charging connector used with a charging station for an electric vehicle wherein the charging connector mates to a charging coupler of the electric vehicle during charging includes a housing mechanically configured generally similarly to the charging coupler enabling the housing to mechanically mate to the charging connector; and a cleaning contact, coupled to the housing and complementary to the socket, for engaging the socket and removing surface contaminants from the socket whenever the housing mechanically mates to the charging connector.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to charging stations for energy storage systems, and more specifically, but not exclusively, to automatic cleaning of contact sockets of a coupler used with an electric vehicle charging station. 
         [0002]    As electric vehicles (EVs) become more prevalent, there is a corresponding increase of installations for charging stations used with the EVs. These charging stations are installed at public and private locations, with either of the installations being classified as an indoor or an outdoor installation. 
         [0003]    Each charging station includes an electrical coupler that includes two or more contacts that mate with the charging system of the EV. Dust and grime builds up on the contacts over time, particularly for electrical couplers used in public and/or outdoor installations. This contamination decreases the life of the electrical coupler and increases the electrical contact resistance between the coupler and the EV charging system. (Particulate contamination further provides a physical barrier on the contact surfaces that dramatically increases the contact resistance of a mated connection.) 
         [0004]    Charging efficiency is very important in EV charging because of the large amounts of energy typically transferred during operation. Reducing charging inefficiencies is a system-wide goal for manufacturers, operators, and users. Outdoor charging stations are at great risk for developing unacceptable levels of contamination, particularly those in dusty areas. Public charging stations that are used many times per day are also at increased risk. Thus outdoor public charging stations that are used frequently have, in general, the greatest risk of wasting significant amounts of energy and user time. 
         [0005]    To combat the contamination, these charging stations have a maintenance schedule in which a technician periodically cleans the contacts. The more at risk charging stations may have more frequent maintenance schedules, with any increase in maintenance schedule directly increasing operating costs for the charging station and decreasing availability for charging. Any on-site automatic maintenance performed between technician cleanings may extend the schedule and decrease costs and improve day-to-day charging efficiencies. Particularly as it can be the case that unplanned for increases of contamination between maintenance cleanings results in unacceptable charging efficiencies in the interim between the increase and the cleaning. 
         [0006]    What is needed is an automatic cleaning contact apparatus and method that performs regular light cleaning of the contact surfaces. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Disclosed is an automatic cleaning contact apparatus and method that performs regular light cleaning of the contact surfaces. The following summary of the invention is provided to facilitate an understanding of some of technical features related to EV charging, and is not intended to be a full description of the present invention. A full appreciation of the various aspects of the invention can be gained by taking the entire specification, claims, drawings, and abstract as a whole. 
         [0008]    A contamination cleaner for a socket of a charging connector used with a charging station for an electric vehicle wherein the charging connector mates to a charging coupler of the electric vehicle during charging includes a housing mechanically configured generally similarly to the charging coupler enabling the housing to mechanically mate to the charging connector; and a cleaning contact, coupled to the housing and complementary to the socket, for engaging the socket and removing surface contaminants from the socket whenever the housing mechanically mates to the charging connector. 
         [0009]    A cleaning method for removing contamination from a socket of a charging connector used with a charging station for an electric vehicle wherein the charging connector mates to a charging coupler of the electric vehicle during charging includes a) mating a housing to the charging connector when the charging connector is disengaged from the electric vehicle; and b) engaging the socket with a cleaning contact of the housing to automatically remove surface contaminants from the socket whenever the housing mates to the charging connector. 
         [0010]    Contact resistance, particularly contact resistance caused by foreign particulate matter on active contacts of a charger coupler, is simply and effectively reduced by implementations of the present invention. The user is not impacted at all by the passive maintenance action and there is no user training or alteration of the user&#39;s actions to obtain benefits of the present invention. In some cases, timing of technician visits for regular maintenance is extended, reducing costs and increasing availability of the charging stations employing the present invention. 
         [0011]    The present invention is versatile and may be used with stationary or mobile chargers having one or more charging connectors. Stationary chargers may have the cleaning contact(s) incorporated in a housing element that supports/stores the charging connector between uses. Mobile chargers may have the cleaning contact(s) incorporated into a cap used for the mobile charging connector that covers the mobile connector between uses. 
         [0012]    Other features, benefits, and advantages of the present invention will be apparent upon a review of the present disclosure, including the specification, drawings, and claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention. 
           [0014]      FIG. 1  illustrates a schematic representation of a stand-alone electric vehicle charging station; 
           [0015]      FIG. 2  illustrates a schematic block diagram of interface details of an embodiment of the present invention with the charging connector shown in  FIG. 1 ; 
           [0016]      FIG. 3  illustrates a schematic block diagram of an alternate implementation of the present invention incorporating a motor; 
           [0017]      FIG. 4  illustrates a schematic block diagram of an alternate motorized implementation of the present invention; 
           [0018]      FIG. 5  through  FIG. 10  illustrate representative cleaning contacts for use with various implementations of the present invention; 
           [0019]      FIG. 5  illustrates a cleaning structure with wide wiper sections; 
           [0020]      FIG. 6  illustrates a cleaning structure having one or more cleaning balls; 
           [0021]      FIG. 7  illustrates a cleaning structure having simple bristles; 
           [0022]      FIG. 8  illustrates a cleaning structure having one or more foam cones; 
           [0023]      FIG. 9  illustrates a cleaning structure including one or more spirally wound cleaning elements; and 
           [0024]      FIG. 10  illustrates a cleaning structure including one or more flexible surfaces arranged into a barbed or “christmas tree” configuration. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0025]    Embodiments of the present invention provide an automatic cleaning contact apparatus and method that performs regular light cleaning of the contact surfaces of a charging connector. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. 
         [0026]      FIG. 1  illustrates a schematic representation of a stand-alone electric vehicle (EV) charging station  100  such as would be used at a public and/or outdoor installation. Station  100  includes a housing  105  supporting an informational/control interface  110  for receiving user input and displaying information. A charging connector  115  is communicated to housing  100  using a cord  120 . When not in use, connector  115  is “hung” up on at an attachment point  130  of housing  100 . 
         [0027]      FIG. 2  illustrates a schematic block diagram of interface details of an embodiment of the present invention with a portion  200  of charging connector  115  (connector  115  shown in  FIG. 1 ). Portion  200  includes a shell housing  205  supporting active electrical sockets  210 . Housing  205  insulates and protects the user from accidental contact with sockets  210  and provides some environmental protection for sockets  210  as well as providing a desired mating interface for connection to a complementary mating interface of the EV. 
         [0028]    Sockets  210  are shown as female sockets carrying charging energy for delivery to the energy storage system of an EV. In  FIG. 2 , portion  200  is shown with two female electrical sockets  210 , however the present invention is not limited to a particular number or type (e.g., female or male) of active sockets. 
         [0029]    A cleaning coupler  215  including an embodiment of the present invention mechanically mates to portion  200  and therefore includes a housing  220  complementary to housing  205 . Housing  220  supports one or more cleaning contacts  225  that interface with socket(s)  210  of portion  200 . (In some cases, contacts  225  are referred to as “dummy” pins in that they replicate in varying detail, mechanical interface structure of electrical contacts used in the EV to receive charging power from socket(s)  210 .) Housing  220  is located at attachment point  130  shown in  FIG. 1 . 
         [0030]    Cleaning contact  225  engages a corresponding socket  210  and removes surface contaminants from socket  210  whenever housing  220  mechanically mates to housing  205 . Housing  220  may include one or more optional guide pins  230  to guide cleaning contact  225  into cleaning engagement with socket  210  by matching to a guide channel  235  in housing  205 . Typically walls of housing  220  are sufficient to mate the cleaning contact(s) with the socket(s). 
         [0031]    There are many configurations for cleaning contact  225  and many ways that contact  225  may engage socket  210  and remove contaminants. Some of these configurations and ways are further described herein to illustrate a range of implementations of the present invention but are not intended to limit its scope. 
         [0032]    In operation, a user decouples connector  115  from the charging power coupler of their EV and stores connector  115  on station  100  in some fashion, such as by “hanging” or the like. Preferably housing  220  is incorporated into housing  105  and is part of the storage system for connector  115 . Each time a user stores connector  115 , housing  205  (part of connector  115 ) engages housing  220  to automatically engage cleaning contact(s)  225  with socket(s)  210 . This passively removes surface contaminants from socket(s)  210  and decreases contact resistance of socket(s)  210  when a subsequent user operates station  100 . 
         [0033]    Preferably the cleaning by contact(s)  225  is gentle (e.g., non-abrasive) to socket(s)  210  and is implemented in a way that can be transparent to the user. Each and every time connector  115  is stored at station  100 , contact(s)  225  passively remove surface contaminants from socket(s)  210 . The transparency refers to the user not being impacted at all including no training sessions or alterations to normal routines used when charging their EV from charging station  100 . One of the features of the present invention is leveraging an action that is often, if not always, performed (i.e., storing connector  115  in housing  105 ) with the associated passive cleaning/maintenance action (e.g., removing contaminants from socket(s)  210 ). This offers improved useful life for the socket(s) and reduces risks of overheating as well as some upside in passively improving day-in day-out charging efficiency, all without significant cost or user inconvenience while in some cases decreasing certain scheduled maintenance tasks which reduces costs and increases availability of station  100 . 
         [0034]    Socket(s)  210  are typically silver plated over a copper core. The construction style and type of materials is most relevant in that this information helps to ensure that an implemented solution for cleaning contact(s)  225  is gentle enough to not unduly wear out socket(s)  210  when used as described herein. A preferred implementation includes a pliable polymer material arranged in a soft bristle format that has an effective diameter at least slightly greater than an inside diameter of socket(s)  210 . 
         [0035]    Preferably cleaning contact(s)  225  are implemented to simply remove dirt, dust, and in some cases moisture/water, but are not designed to be abrasive enough to remove any intended coating(s) and/or oxide layer(s) installed on an inner surface of socket(s)  210 . In some cases where an oxide layer is provided on contact surfaces of sockets  210  that is essential to surface protection, the surface contaminants targeted by the present invention for cleaning would be more destructive to the oxide layer if left in place during electrical mating than is the case with the cleaning action of contacts  225  when removing such surface contaminants. 
         [0036]    In addition to stationary charging stations  100 , there are mobile charging stations that in some cases may not include the same type of housing or other structure devoted to “hanging” up connector  115 . In such cases, those connectors  115  associated with a mobile charging solution can have a cover or cap offering some environmental protection to inhibit ingress of contaminants and the like (as well as reducing risks to the user from accidental contact). Housing  220  may be incorporated into such a cover or cap and operate in a similar fashion to automatically clean surface contaminants from socket(s)  210  each time that the cover or cap is placed on connector  115 . 
         [0037]    It is not required that contacts  225  will need servicing or maintenance. In some cases where cleaning of contacts  225  is necessary or desirable, a custom tool is available that resembles portion  200  but having cleaning elements substituted for socket(s)  210 . 
         [0038]      FIG. 3  illustrates a schematic block diagram of an alternate implementation of the present invention for a cleaning coupler  300  incorporating a motor  305 . Cleaning coupler  300  mechanically mates to portion  200  shown in  FIG. 2  and provides a housing  310  complementary to housing  205 . Housing  310  supports one or more active cleaning contacts  315  that interface with socket(s)  210  of portion  200 . Contacts  315  have a linkage  320  that couples to motor  305  to produce the desired cleaning action, with motor  305  driving the cleaning action through an appropriate linkage  320 . 
         [0039]    Cleaning contact  315  engages a corresponding socket  210  and removes surface contaminants from socket  210  whenever housing  310  mechanically mates to housing  205  or on a regular schedule. Housing  310  may include a housing with optional guiding features  325  to guide cleaning contact  315  into cleaning engagement with socket  210  by matching to guide channel  235  in housing  205 . 
         [0040]    Cleaning coupler  300  includes a mechanically-implemented linkage  320  to provide a mechanical cleaning action. Contact  315  may rotate about an longitudinal axis, linearly move parallel to the axis, or pitch/yaw the axis. Rotation preferably includes reciprocating motion in which there is rotation of contact  315  in one direction and then in the opposite direction inside socket  210 . Reciprocating linear movement of contact  315  provides for contact  315  to advance into and retreat from socket  210 . Pitching/yawing “tilts” contact  315  within socket  315 . There are many different ways to implement the various described representative cleaning actions, details of which are outside the scope of the present invention. 
         [0041]      FIG. 4  illustrates a schematic block diagram of an alternate motorized implementation of the present invention for a cleaning coupler  400 . In contrast to coupler  300 , coupler  400  incorporates a pumping motor  405  to drive a cleaning fluid or solvent from a reservoir  410 . Coupler  400  includes a housing  415  supporting motor  405  and reservoir  410 . Cleaning coupler  400  mechanically mates to portion  200  shown in  FIG. 2  and provides housing  415  complementary to housing  205 . Housing  415  supports one or more active cleaning contacts  420  that interface with socket(s)  210  of portion  200 . Contacts  420  have a linkage  425  that couples to motor  405  to produce the desired cleaning action by coupling contents of reservoir  410  to contact(s)  420 , with motor  405  driving the cleaning action by pumping fluid/solvent under pressure through linkage  425 . 
         [0042]    Cleaning contact  420  engages a corresponding socket  210  and removes surface contaminants from socket  210  whenever housing  415  mechanically mates to housing  205 . Housing  415  may include one or more guide pins  430  to guide cleaning contact  420  into cleaning engagement with socket  210  by matching to guide channel  235  in housing  205 . 
         [0043]    Cleaning coupler  400  includes a pressurized fluid implemented linkage  425  to provide a mechanical cleaning action that includes communicating a stream of the pressurized fluid from motor  405  to contact  420 . Contact  420  includes one or more nozzles, jets and the like to produce a spraying action or the like that directs one or more streams  435  of the fluid/solvent from reservoir  410  into socket  210  to flush, dislodge, and the like to remove surface contaminants from socket  210 . Some implementations may include a hybrid solution that includes both a mechanical cleaning action and a pressurized fluid cleaning action. There are many different ways to implement the various described representative cleaning actions, details of which are outside the scope of the present invention. 
         [0044]      FIG. 5  through  FIG. 10  illustrate representative cleaning contacts for use with various implementations of the present invention described herein. 
         [0045]      FIG. 5  illustrates a cleaning structure  500  with a plurality of wide wiper sections  505  disposed on a shaft  510 . Cleaning structure  500  may be preferably used with coupler  300  including a rotating cleaning action for the cleaning contact. 
         [0046]      FIG. 6  illustrates a cleaning structure  600  having one or more cleaning balls  605  disposed on a shaft  610 . A series of such balls  605  (more generally an ovoid periphery) along shaft  610  preferably have a diameter at least slighter greater than an inside diameter of sockets  210 . Balls  605  may be hollow or solid core. 
         [0047]      FIG. 7  illustrates a cleaning structure  700  having simple bristles  705  disposed on a shaft  710 . Bristles  705  extend in multiple directions generally perpendicular to shaft  710 . 
         [0048]      FIG. 8  illustrates a cleaning structure  800  having one or more foam (or similar resilient material) cones  805  disposed on a shaft  810 . Cones  805  may be hollow or solid core. 
         [0049]      FIG. 9  illustrates a cleaning structure  900  including one or more spirally wound cleaning elements  905 , element(s)  905  wound about a shaft  910 . 
         [0050]      FIG. 10  illustrates a cleaning structure  1000  including one or more generally “flat” flexible cleaning surfaces  1005  arranged into a barbed or “christmas tree” configuration relative to a shaft  1010 . Cleaning structure  1000  provides for surfaces  1005  to “flatten” as shaft  1010  is inserted into socket  210  and expand outwardly as shaft  1010  is withdrawn from socket  210 . 
         [0051]    Preferably the embodiments shown in  FIG. 5  through  FIG. 10  all share a similar construction element that a profile of the peripheral of the cleaning/dislodging elements is slightly larger than the inside diameter of socket  210 . 
         [0052]    As noted herein, the system and process are most preferably implemented in a charging station (stationary, mobile or otherwise) for an electric vehicle. The present invention may be implemented for virtually any charging station having connectors of differing number, shapes, orientations, and types than described herein or on any electrical connector having pin and socket contacts. While the overall cleaning is described as passive insofar as the cleaning occurs in conjunction with some other required action of the user, in some embodiments the cleaning contacts include one or more active cleaning actions, such as driven by a motor or the like. 
         [0053]    The system and methods above has been described in general terms as an aid to understanding details of preferred embodiments of the present invention. Other preferred embodiments of the present include the described application for a contact cleaning apparatus and method. In the description herein, numerous specific details are provided, such as examples of components and/or methods, to provide a thorough understanding of embodiments of the present invention. One skilled in the relevant art will recognize, however, that an embodiment of the invention can be practiced without one or more of the specific details, or with other apparatus, systems, assemblies, methods, components, materials, parts, and/or the like. In other instances, well-known structures, materials, or operations are not specifically shown or described in detail to avoid obscuring aspects of embodiments of the present invention. 
         [0054]    Reference throughout this specification to “one embodiment”, “an embodiment”, or “a specific embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention and not necessarily in all embodiments. Thus, respective appearances of the phrases “in one embodiment”, “in an embodiment”, or “in a specific embodiment” in various places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined in any suitable manner with one or more other embodiments. It is to be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the present invention. 
         [0055]    It will also be appreciated that one or more of the elements depicted in the drawings/figures can also be implemented in a more separated or integrated manner, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. 
         [0056]    Additionally, any signal arrows in the drawings/Figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted. Furthermore, the term “or” as used herein is generally intended to mean “and/or” unless otherwise indicated. Combinations of components or steps will also be considered as being noted, where terminology is foreseen as rendering the ability to separate or combine is unclear. 
         [0057]    As used in the description herein and throughout the claims that follow, “a”, “an”, and “the” includes plural references unless the context clearly dictates otherwise. Also, as used in the description herein and throughout the claims that follow, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise. 
         [0058]    The foregoing description of illustrated embodiments of the present invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed herein. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention, as those skilled in the relevant art will recognize and appreciate. As indicated, these modifications may be made to the present invention in light of the foregoing description of illustrated embodiments of the present invention and are to be included within the spirit and scope of the present invention. 
         [0059]    Thus, while the present invention has been described herein with reference to particular embodiments thereof, a latitude of modification, various changes and substitutions are intended in the foregoing disclosures, and it will be appreciated that in some instances some features of embodiments of the invention will be employed without a corresponding use of other features without departing from the scope and spirit of the invention as set forth. Therefore, many modifications may be made to adapt a particular situation or material to the essential scope and spirit of the present invention. It is intended that the invention not be limited to the particular terms used in following claims and/or to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Thus, the scope of the invention is to be determined solely by the appended claims.