Abstract:
A system for coiling an electrical cable employed for charging an electric vehicle employs a cable management system. The cable management system has a drive assembly which has a drive mode that retracts the cable and release mode which allows for the cable to be extended. The installation employs a drum having a cylindrical sidewall. The drive assembly drives the cable downwardly into a drum so that the cable progressively engages the sidewall to form a vertical coiled configuration. A clutch assembly cooperates with the drive assembly to provide the automatic retracting and extending operations and also locks the vehicle connector at the end of the electrical cable in an extended position as well as a retracted home position.

Description:
BACKGROUND 
       [0001]    This disclosure relates generally to installations for charging the power supply of an electric vehicle. More particularly, this disclosure relates to charging stations which employ an electric cable having a connector for electrically connecting with the battery power charging unit of the electric vehicle (EV). 
         [0002]    With the large number of electric vehicle chargers being deployed for public use, there has arisen a need to manage the electric cable that connects the electric vehicle to the electric vehicle supply or service equipment (EVSE). When the cable is not stored properly or left on the ground or pavement, it is exposed to the elements, such as rain, snow, ice and dirt. The cables left on the ground also become a tripping hazard. 
         [0003]    Publicly accessible EVSE installations have become widespread and assume numerous configurations and capabilities. Commonly, publicly accessible EVSE is a post-mounted installation having a permanently attached electrical cable which may extend up to 25 feet in order to accommodate the connection to the electric vehicle. From a safety standpoint, it is exceedingly important that the cable cannot be excessively extended when not in use and that the electric cable not be allowed to lie on the pavement or adjacent area where it can be exposed to the elements, damaged, run-over or otherwise degraded. 
         [0004]    Because the EVSE installations are now typically compact, providing for an efficient and effective extension of the cable and suitable retraction and/or limiting the extension of the cable has become problematic. Ideally, the cable should be retracted into a protective housing when not in use so that only the connector end of the cable is exposed for grasping by the user to connect to the EV for charging.  
         [0005]    Naturally, it is highly desirable that any mechanism which allows the power cable to be extended and retracted must be reliable and efficient since the functionality of the EVSE is very dependent upon the connectivity to the electric vehicle and the integrity of the electrical connection. 
       SUMMARY 
       [0006]    Briefly stated, in one embodiment, an EVSE installation comprises a drum having a cylindrical side wall with a generally vertical central axis and a top. An electrical cable with a vehicle connector at one end and connectable to a power supply at the other end is retractable and extendable into and from the drum. A cable management system comprises an automatic drive assembly for the electrical cable. The drive assembly has a drive mode to retract the cable and a release mode to extend the cable. The drive assembly drives the cable into the drum so that the cable progressively engages the sidewall to form a vertical coiled configuration and the cable and connector are disposed at a stable home position. 
         [0007]    The drum is preferably supported on a pole or a wall. The cable management system comprises a clutch mechanism that remains locked when no power supplied. The EVSE installation further preferably comprises an enclosure for the drum. The enclosure has a front cover that mounts a control panel and receives the vehicle connector at the home position. The drive assembly comprises a motor and a drive gear rotatably connecting with a drive pulley. The cable management system also comprises a clutch mechanism controlled by a clutch solenoid. The clutch mechanism preferably further comprises a clutch gear, a clutch lever and a spring attached to the clutch lever. Upon de-energizing the clutch solenoid, the clutch gear engages the drive gear. 
         [0008]    Upon sensing the connection of the vehicle connector to an electric vehicle, the solenoid and the motor are not energized and the drive pulley is thereby locked to prevent further extension of the cable. Upon energizing the solenoid, the lever pivots and the clutch gear separates from the drive gear so that the pulley drive gear is free to rotate and the cable is freely extendable.  Upon disconnecting the vehicle connector from the electric vehicle, the cable is automatically retracted into the drum by the drive assembly. 
         [0009]    The EVSE installation preferably comprises a sensor that senses the home position of the cable and the connector. The sensor is a magnetic sensor. The EVSE installation further has a centering guide ring through which the cable passes. 
         [0010]    In one embodiment of an EVSE installation, the drum defines a generally cylindrical container with a centering guide ring. An electrical cable with a vehicle connector at one end and connectable to a power supply at the other end is retractable and extendable through the centering ring into and from the drum. The cable management system comprises a drive assembly for the electrical cable. The drive assembly has a drive mode to automatically retract the cable and a release mode to allow the cable to extend from the drum. The drive assembly automatically drives the cable into the drum so that the cable progressively engages the container to form a coiled configuration and continues until the cable and connector are disposed at a stable home position. 
         [0011]    The cable management system includes a clutch mechanism and the drive assembly comprises a motor operatively engageable with the clutch mechanism. The clutch mechanism operatively engages with the motor to lock the connector at the home position. The drive assembly comprises a motor and a drive gear which rotatably connects with a drive pulley. The clutch mechanism is controlled by a solenoid. Upon energizing the solenoid, a clutch gear of the clutch mechanism separates from the drive gear so that the pulley drive gear is free to rotate and the cable is freely extendable. 
         [0012]    A method of coiling and storing an electrical cable with a vehicle connector for EVSE preferably comprises providing a drum having a generally cylindrical sidewall with a generally vertical central axis and a top. The method further comprises automatically retracting the cable by downwardly driving the cable into the drum so that the coil engages against the sidewall to form a vertical coiled configuration and the connector is at a home position and allowing the cable and connector to be extended from the home position.  
         [0013]    The method further preferably comprises automatically locking the cable and connector in an extended position and further automatically locking the cable connector in the home position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is an isometric view of the EVSE assembly with motorized cable retracting capabilities, mounted on a pole; 
           [0015]      FIG. 2  is an isometric view of the EVSE assembly with motorized cable retracting capabilities, mounted on a wall; 
           [0016]      FIG. 3  is an isometric view of the EVSE assembly with motorized cable retracting capabilities, with the cover removed; 
           [0017]      FIG. 3 a    is an isometric view of the EVSE assembly with motorized cable retracting capabilities, with the cover and connector pocket removed; 
           [0018]      FIG. 3 b    is an isometric view of the EVSE front cover; 
           [0019]      FIG. 3 c    is an isometric view of the EVSE connector pocket; 
           [0020]      FIG. 3 d    is an isometric view of the EVSE top cover; 
           [0021]      FIG. 4  is a side view of the motorized cable and a drive assembly with a solenoid clutch plate assembly; 
           [0022]      FIG. 4 a    is a side view of the cable and drive assembly of  FIG. 4  with the clutch plate assembly removed and a clutch gear in an engaged position; 
           [0023]      FIG. 4 b    is a side view of the cable and drive assembly of  FIG. 4  with the clutch plate assembly removed and the clutch gear in a disengaged position; 
           [0024]      FIG. 5  is a top view of the motorized cable retracting drive assembly; 
           [0025]      FIG. 6  is an exploded view of the motorized cable and various assemblies; 
           [0026]      FIG. 7  is a top view of a cable centering guide ring and a storage cylinder; 
           [0027]      FIG. 8  is a side view, partly diagrammatic, of a cable cleaning and home sensing assembly with a magnet below the home position;  
           [0028]      FIG. 8 a    is a side view of the cable cleaning and home sensing assembly of  FIG. 8  with the magnet at the home position; 
           [0029]      FIG. 9  is an elevational view of the EVSE and schematically illustrating a connection to an electric vehicle; 
           [0030]      FIG. 10  is a composite schematic diagram of the cable management motor drive circuit for the EVSE; and 
           [0031]      FIG. 11  is a timing diagram of the cable management motor drive system for the EVSE. 
       
    
    
     DETAILED DESCRIPTION 
       [0032]    The electric vehicle service or supply equipment (EVSE)  100 , which incorporates a motorized cable retraction system for coiling the cable, may be either mounted to a pole  104  ( FIG. 1 ) or to a wall  109  ( FIG. 2 ). EVSE  100  employs a motorized cable management system for coiling a power cable  101  having a connector  102  which preferably complies with J1772 standards. 
         [0033]    EVSE  100  generally comprises five major sub-assemblies as follows: 
         [0034]    an enclosure, which includes a front cover  111 , a mounting frame  106 , and a power connector pocket panel  112 ; 
         [0035]    a cable drive pulley and clutch assembly  200 , which comprises a cable drive motor  203 , a drive motor gear box  202 , a motor drive gear  204 , a clutch lever  211 , a clutch gear  205 , a cable pulley drive gear  206 , and a cable drive pulley  207 ; 
         [0036]    a cable storage assembly  300 , which comprises a drum or a cable storage cylinder  301  and a mounting bracket  303 ; 
         [0037]    a cable guide and home position sensor assembly  400 , which comprise cable guide rollers  401 , a cable brush cleaner  402 , a ring magnet  403 , a magnetic sensor  405 , and a magnetic sensor PC card  406 ; and 
         [0038]    an EVSE control and a ground-fault circuit interrupter (GFCI) module  500 .  
         [0039]    When the electric vehicle service equipment  100  is not in use, the EVSE power cable  101  is retracted until the EVSE power connector  102  is at the home position indicated by  108  ( FIGS. 1 &amp; 2 ). 
         [0040]    When in the home position, the cable  101  is locked (indicated at  708   a ) and stored in the protective cable storage cylinder  300  ( FIG. 3 ) (indicated at  709   a ). 
         [0041]    With additional reference to  FIG. 11 , when authorized (indicated at  701   a ) in the  FIG. 11  timing diagram, a user presses the on button  110 , on the control module and status indicator  103 . The drive motor  203  is momentarily energized (indicated at  704   a ) with counterclockwise rotation (indicated at  705   a ), and the clutch solenoid  212  is energized (indicated at  706   a ). The clutch solenoid  212  is energized such that the clutch solenoid plunger  214  will be pulled into the clutch solenoid  212 . The clutch solenoid plunger  214 , which is operatively attached to the clutch lever  211 , the clutch return spring  213 , and the clutch gear shaft  210 , will cause the clutch lever  211  to rotate around the clutch lever pivot post  208 . With reference to  FIG. 4 b   , this rotation separates the clutch gear  205  from the cable pulley drive gear  206  (indicated at  708   a ). Once the clutch gear  205  has separated from the cable pulley drive gear  206  (indicated at  708   b ), the voltage to the clutch solenoid is pulsed (indicated at  706   b ) to reduce the power and prevent the clutch solenoid  212  from overheating. To assist in the separation, the drive motor  203  is energized (indicated at  704 ) in the counterclockwise rotation direction for a short period of time. 
         [0042]    The cable drive pulley  207  is free to rotate. The latter allows the user to simply extend (indicated at  709   b ) the EVSE power cable  101  until it reaches the electric vehicle power inlet  601  (indicated at  709   c ) on the electric vehicle  600  ( FIG. 9 ). The EVSE power cable  101  may be extended from the cable storage cylinder  300  until it is restrained by the cable restraining bracket  303  ( FIG. 6 ). 
         [0043]    Once the EVSE power connector  102  is attached to the electric vehicle power inlet  601  and the charging cycle is initiated by the EVSE control  and ground-fault circuit interrupter (GFCI) module  500 , the clutch solenoid  212  is deactivated. The deactivation allows the clutch spring  213  attached to the clutch lever  211  and the clutch spring attachment post  214  to pull the clutch lever  211  and the clutch gear  205  to reengage with the cable pulley drive gear  206 . 
         [0044]    When the connection to the electric vehicle  600  is sensed (indicated at  711   a ) by the EVSE control and GFCI module  500 , the clutch solenoid  212  will be de-energized (indicated at  706   c ), the clutch return spring  213  will cause the clutch lever  211  to re-engage the clutch gear  205  with the cable pulley drive gear  206  (indicated at  707   b ). Because the drive motor  203  is not energized (indicated at  704   b ), the cable drive pulley  207  is now locked, preventing the further extension (indicated at  709   c ) of the EVSE power cable  101  and the EVSE power connector  102 . 
         [0045]    When the power cable  101  is unlocked (indicated at  708   b ), the cable connected timer is started (indicated at  710   a ). If the cable connected timer times out (indicated at  710   c ) before the power connector  102  is connected to the electric vehicle  600  power inlet  601 , the power cable  101  will be retracted (indicated at  709   d ) until it reaches the home position (indicated at  709   e ). When the power connector  102  reaches the home position  108 , the power cable  101  will be locked in place (indicated at  708   c ). 
         [0046]    When engaged, the cable drive pulley  207  will be in a locked position as long as the drive motor  203  is not powered. This will prevent the EVSE power cable  101  from being extended further. This locking feature is created by the fact that the drive motor gear box  202  is not easily driven in reverse. 
         [0047]    When the EVSE power connector  102  is detached from the electric vehicle power inlet  601 , the electrical power will be disconnected from the EVSE power connector  102  by the EVSE control and GFCI module  500 . Power is applied to the cable drive motor  203  with a polarity that will cause it to drive in the clockwise direction (indicated at  704 ). The clockwise rotation of the cable pulley drive gear  206 , which is attached to the cable drive pulley  207 , will cause the retraction of the EVSE power cable  101 .  
         [0048]    As the EVSE power cable  101  enters the cable storage assembly  300  through the cable centering guide ring  218 , it is forced against the cylinder wall  304 , causing the cable to stack up  305  in a coiled configuration. 
         [0049]    As the EVSE power cable  101  is returning to the home position, it will pass through the cable guide rollers  404  and the cable brush cleaner  402 . As the cable home ring  107  reaches the home position (indicated at  702   c ), it will pick up the ring magnet  403  to the point that it passes the magnetic sensor  405 . When the magnetic sensor  405  senses the ring magnet  403  (indicated at  703   c ), the sensor PC card  406  will send a signal (indicated at  703 ) to the EVSE control and GFCI module  500  to turn off the return drive motor  203  (indicated at  704   e ). 
         [0050]    Because the clutch return spring  213  is keeping the clutch gear  205  engaged, the EVSE power cable  101  and the EVSE power connector  102  are locked in the home position  108 . 
         [0051]    The disclosed EVSE assembly stores the cable internally protected from the elements, while still presenting easy access to the power connector. When not in use the cable and connector are locked in position. The user may easily extend the charging cable between the electric vehicle and the EVSE unit while keeping the cable off of the ground. When the user disconnects the power connector from the vehicle, the cable is automatically retracted and stored internally in the EVSE, eliminating the tripping hazard. Preferably, the power connector hangs in a partly protected shell, four feet off of the ground and easily accessible. 
         [0052]    The automatic system used for retracting and coiling the electrical cable does not use slip rings. 
         [0053]    While preferred embodiments have been set forth for purposes of illustration, the foregoing descriptions should not be deemed a limitation of the invention herein. Accordingly, various modifications, adaptations and alternatives may occur to one skilled in the art without departing from the spirit and the scope of the present invention.