Abstract:
A charging system which is particularly suitable for recharging the batteries of electrically powered motor vehicles using a charge head with multiple contacts that mate with an array of charge receiving electrodes onboard the vehicle being recharged. The charge head is supported from overhead, and may, using a power assisted system, be lowered, into place against the array of charge receiving electrodes onboard the vehicle. Switches may be spaced apart so that, like the grasping elements of the handle, use of both hands is required. The charge head causes breaking of series connections of batteries within the vehicle so that individual batteries may be charged in parallel. A battery temperature monitor is provided. An annunciator locally or remotely signals errors or indicates completion of charge. Payments are accepted near the charge head, thereby allowing for commercial operation.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to application Ser. No. 12/657,533, now issued as U.S. Pat. No. 8,174,238, entitled CHARGING CONTACT ARRAY FOR ENABLING PARALLEL CHARGING AND SERIES DISCHARGING OF BATTERIES, filed concurrently herewith and incorporated herein in its entirety by reference. 
     FIELD OF THE INVENTION 
     The present invention pertains to apparatus for charging of battery packs, and more particularly, to apparatus which is suitable for the public (i.e., untrained lay persons) to charge battery packs of electrically operated vehicles. 
     BACKGROUND OF THE INVENTION 
     Electrically powered motor vehicles typically carry batteries for supplying operating power. These batteries may periodically need to be recharged from an external power source. Recharging can be accomplished in a number of ways. The vehicle may be a purely electrically operated vehicle, so that operation is fully dependent upon charge remaining in the batteries. Alternatively, the vehicle may be a hybrid having an onboard internal combustion engine, wherein the internal combustion engine may take over from the electrical power plant or may supplement the electrical power plant by providing some of the power necessary for operation, and/or by charging the vehicle&#39;s onboard batteries. In addition, the vehicle may have a regenerative braking feature in which braking operates a dynamic brake which also functions as a generator for recharging the batteries. 
     Regardless of the type of vehicle or the operating scheme, commercially available electrically operated vehicles both of the purely electrical type or the so-called plug-in hybrid type, it may be necessary or desirable that the batteries be recharged while the vehicle is enroute. Such a charging need is similar to the need in a vehicle powered by fossil fuel (e.g., gas or diesel) that periodically stops at a fueling station to refill the vehicle&#39;s fuel tank(s). 
     Recharging of batteries suitable for powering electrically powered vehicles presents conflicting demands. It is desirable to minimize the time interval during which the vehicle is being charged. However, it is also desirable to limit voltages present during charging due to safety concerns presented by the relatively high operating voltage used in many electrically powered vehicles. It is, however, possible to recharge batteries at limited voltage by charging individual cells or groups of batteries in parallel. One approach is to separate individual cells or batteries normally series connected (to achieve the necessary high operating voltage), recharge the cells in parallel at a relatively low voltage, and then reconnect the batteries in series again. However, if the charging time is to be limited, the current must be increased accordingly. 
     Inductive couplings have been developed to facilitate ready battery recharging. However, inductive couplings introduce inefficiencies, notably, heating losses from induction. It is preferable to provide direct mechanical connection between charging conductors and those conductors leading to the batteries being charged to avoid inductive losses. 
     Batteries can be charged over long periods of time (i.e., trickle charged), for example overnight at the residence of the operator or all day at the operator&#39;s place of business. However, even the largest capacity contemporary batteries are limited as to the practical cruising range of their associated vehicles. For relatively short “out and back” trips such as commuting to a workplace, an overnight trickle charge may be sufficient to power the vehicle. However, for longer trips, it becomes very likely that many electric vehicles will have to be recharged between a departure point and a destination. 
     Passenger vehicles are consumer items. That is, they are typically operated by laymen, or people who are not trained in the mechanics and electrical systems of passenger vehicles. It is, therefore, necessary that any system for recharging the batteries of electrically powered vehicles be simple to operate and include inherent safety features so that consumers can safely recharge their vehicles. 
     It is, therefore, highly desirable to provide charging apparatus that may readily be used by ordinary motorists driving electrical vehicles. Despite relatively great size and weight which are demanded by relatively high current capacity, the charging apparatus/equipment must be reasonably easy to maneuver and inherently safe. 
     There exists a need for a practical way to arrange relatively expeditious, relatively safe recharging at commercial premises for operators of electrical vehicles. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention there is provided a charging system which is particularly suitable for recharging the batteries of electrically powered motor vehicles by consumers at commercial or other dedicated recharging stations. The charging system of the invention has a charge head, typically having multiple contacts that may be coupled to an array of charge receiving electrodes onboard the vehicle being recharged. The charge head is supported from overhead, and may be lowered into place against the array of charge receiving electrodes onboard the vehicle being charged. 
     The charging system may have a power assisted charge head lowering and raising system, and may also be jointed and/or articulated so as to enable the charge head to move throughout six degrees of freedom when being maneuvered into place against the array of charge-receiving contacts associated with the electrically powered vehicle. The charge head typically has a handle comprising spaced apart grasping elements so as to oblige the use of both hands when maneuvering the charge head into place. Dead man switches may be included to inhibit system operations unless both hands are used simultaneously. The dead man switches may be spaced apart so that, like the grasping elements of the handle, both hands are required. 
     The charging electrodes of the charge head may be partially covered by a protective cover to help prevent live charging electrodes from contacting an unintended surface and being unintentionally grounded. 
     The charging head may have a plurality of tapered pins to facilitate alignment of the charging head relative to an array of charge receiving electrodes on the vehicle having corresponding openings for receiving such pins. Other alignment mechanisms are, of course, possible. 
     The charging system may incorporate a monitoring system that monitors the battery temperature and/or an indication of completion of charging. Charge rate may be varied with battery temperature, such as being reduced in rate if relatively high battery temperatures are encountered. In addition to monitoring the temperature of the batteries, the system may be configured to measure cable temperatures, the temperatures of on or more cable connections, or the temperature of the charging contacts. The monitoring system may annunciate completion of charging. Such annunciation may be audible or visual and may be local or remote. Further, annunciation may include a cellular call or text message or another electronic message to cellular telephone, a personal digital assistant (PDA), a pager, or any other suitable device. 
     The charging system may incorporate a payment acceptance apparatus, such as a point of sale credit or debit card processor, so that a consumer can pay for the charge at the charging apparatus. 
     The charging system may include a security system for identifying the motor vehicle to assure that the vehicle is authorized to be charged, is not stolen, and for other security related purposes. 
     It is, therefore, an object of the invention to provide a charging mechanism for batteries of an electrically powered vehicle or any other mobile device containing batteries requiring periodic recharging. 
     It is another object of the invention to provide a charging mechanism having a movable charging head adapted to electrically connect to an array of charge receiving contacts on an electrically powered vehicle. 
     It is an additional object of the invention to provide a charging mechanism that may incorporate means for accepting payment for recharging the batteries of the electrically powered vehicle. 
     It is a further object of the invention to provide a security feature to perform some type of security check on a motor vehicle being charged. 
     It is a still further object of the invention to provide a charging mechanism having an annunciator to inform an operator of a safety concern or of completion of the recharging operation. 
     It is yet another object of the invention to provide a charging mechanism wherein an annunciator sends an electronic message to an electronic device such as a cellular telephone, a PDA, a pager, or another electronic device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
         FIG. 1  is a simplified schematic diagram of the charging system in accordance with the invention in an intended operating environment for charging the batteries of an electrically powered vehicle; 
         FIG. 2  is an enlarged front elevational detail view of the charge head portion of the system of  FIG. 1 ; and 
         FIG. 3  is a detailed diagrammatic perspective view of the charging apparatus of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention provides a charging system for recharging the batteries of electrically powered vehicles or other mobile devices containing batteries requiring periodic recharging. 
     Referring first to  FIG. 1 , there is shown a simplified schematic diagram of the charging system in accordance with the invention in an intended operating environment for charging the batteries of an electrically powered vehicle. 
     A charging electrode system  10  is provided for engaging an array of associated charging electrodes  26  ( FIG. 2 ) disposed in charge transferring relation thereto within an electrically powered vehicle  91  ( FIG. 3 ). The charging electrode system  10  is intended to enable an operator, not shown, of an electrically powered motor vehicle  91  to connect his or her vehicle  91  to commercial recharging facilities encountered along a route being traversed, and to expeditiously charge battery pack  84  within or associated with vehicle  91 . 
     A portion of the charging electrode system  10  of the invention as shown in  FIG. 1  comprises an overhead support  12  for connecting the overhead portion of the charging electrode system  10  to a supporting environmental surface or structure  16 . For example, overhead support  12  may be supportably fixed to a tower  14  anchored to a ground surface  16 . It will be recognized by those of skill in the art that numerous other support arrangements are possible. 
     A boom  18  may project from overhead support  12 . Boom  18  may include a swivel joint  20  having a vertically oriented axis of rotation  22 . 
     A charge head  24  bearing an array of charging electrodes  26  is supported from and depends from boom  18 . The array of charging electrodes  26  comprises at least four charging electrodes  26  and may for example assume a format corresponding to that shown in FIG. 7 of related U.S. utility patent application Ser. No. 12/657,533, now issued as U.S. Pat. No. 8,174,238, entitled CHARGING CONTACT ARRAY FOR ENABLING PARALLEL CHARGING AND SERIES DISCHARGING OF BATTERIES, filed concurrently with the instant application and included herein by reference. Charge head  24  may be selectively lowered into contact with charge receiving electrodes  77  ( FIG. 3 ) of motor vehicle  91  for charging the batteries  84  thereof. 
     Upon completion of the charging operation, Charge head  24  may subsequently be raised to be out of the way of motor vehicle  91 . To accomplish this, charge head  24  is supported by and depends from an overhead suspension system that may include the boom  18  as well as other components that enable the charge head  24  to be maneuvered upwardly, downwardly, and laterally relative to the overhead support  12 . The overhead suspension system may comprise a plurality of rigid members or links such as the rods  28  and  30  and a hydraulic cylinder  32 . Of course, any suitable flexible supporting apparatus such as lengths of chain, not shown, may be incorporated into the overhead suspension system if desired. 
     Hydraulic cylinder  32  will be understood to comprise conventional elements of a hydraulic cylinder assembly, such as a cylindrical chamber enclosing a piston (not separately shown) that may be raised and lowered (as depicted in  FIG. 1 ) by hydraulic fluid under pressure. The piston may be ultimately coupled to the charge head  24 . A source  52  of pressurized hydraulic fluid may provide pressurized hydraulic fluid to act on the piston selectively according to a manual control (to be described hereinafter) so as to raise and lower the charge head  24 . It will be recognized by those of skill in the art that additional, ancillary components, for example, hydraulic supply and return conduits  60 ,  62  are required to operate hydraulic cylinder  32  and these components are assumed to be provided although not described or individually identified. 
     Rod  28  terminates in a clevis  34 . One end of hydraulic cylinder  32  may be coupled to clevis  34  by a connecting member  36  containing a bore, neither visible nor identified in  FIG. 1 , through which an axle  38  extends. Axle  38 , in conjunction with connecting member  36  forms a swivel connection  40  having an axis of rotation  42 . A second swivel connection  44  of construction similar to that of the swivel connection  40  may be provided by a second clevis  46  that terminates rod  30  at a lower end of hydraulic cylinder  32 . The second swivel connection  44  has an axis of rotation  48 . Hydraulic cylinder  32 , which is rigid along its length, may be constructed so that the rod  30  rotates about an axis of rotation  50  that is coaxial with the rod  30 . 
     It will be recognized that the overhead suspension system comprises a plurality of rigid links collectively having at least three swivel connections (i.e., swivel connection  40 , swivel connection  44 , and swivel connection of the rod  30  within the hydraulic cylinder  32 ). The three axes of rotation  42 ,  48 , and  50  may be disposed perpendicularly to one another, thus enabling movement of charge head  24  in two opposed directions within each of three orthogonal directions or in the three dimensions, which is referred to herein as providing six degrees of freedom of motion of the charge head  24 . 
     The hydraulic cylinder  32  forms part of a hydraulic assist system disposed to raise and lower the charge head  24 . Hydraulic cylinder  32  is ultimately supported from overhead support  12 . 
     Referring now also to  FIG. 2 , there is shown a front elevational detailed view of a portion of charge head  24 . Charge head  24  comprises a plate  54  to which the charging electrodes  26  are mounted, depending from a lower surface thereof. Each charging electrode  26  may be enclosed within an electrically insulating sleeve  56 . Each charging electrode  26  may have a flat metallic conductive charge transmitting charging surface  58 . While the charging electrodes  26  may be part of an inductive coupling, not shown, if desired, it is preferred to employ directly contacting conductive surfaces, such as the charging surfaces  58 , between the charging electrodes  26  and the charge receiving electrodes  77  of motor vehicle  91  because inductive coupling charging introduces inefficiencies in electrical transmission. 
     Insulating sleeves  56  may extend well beyond their respective charging electrodes  26  such that the charging surfaces  58  are recessed within their respective sleeves  56 . This feature, which may be regarded as a protective hood arrangement for covering each charging electrode  26  when in charge transferring relation to an electrode being charged by the charging electrode system  10 . This helps prevent unintended paths to ground. It would be possible for the sleeves  56  to be arranged to retract relative to the charging electrodes  26  if desired, this option not shown, so that the charging electrodes  26  could be exposed fully or more than they are in the fully recessed position relative to the sleeves  56 . 
     Charge head  24  may comprise a maneuvering handle  64  coupled thereto. The maneuvering handle  64  may be of the type typically provided in so-called go-karts, and may utilize two bolts  65  to fasten the maneuvering handle  64  to charge head  24 . The maneuvering handle  64  has a first and second padded grasping member  66 ,  68 , respectively, disposed in a spaced apart relationship to one another. This spaced apart arrangement obliges a user to use two hands, not shown, to grasp both first and second grasping elements  66 ,  68  to manipulate charge head  24 . This two-handed approach allows the user to have a better grasp on and control over maneuvering handle  64  and hence over the charge head  24  than would be the case if the maneuvering handle  64  were capable of being grasped in the center by one hand. Also, because both hands are occupied as they grasp the maneuvering handle  64 , they are out of the way of the charge head  24  as it lowers to engage the charge receiving electrodes  77  of motor vehicle  91 , and thus are safe from being pinched by the charge head  24  as it descends. 
     Two types of manual controls may be seen on the maneuvering handle  64 . One is a manual control  70  disposed to cause the pressurized hydraulic fluid to act on the piston of the hydraulic cylinder  32  selectively so as to raise and lower the charge head  24 . Manual control  70  may be a rocker style pushbutton switch which when depressed at the upper end it causes the hydraulic circuit, not shown, to deliver pressurized hydraulic fluid, not shown, to raise the charge head  24 . Conversely, when control  70  is depressed at the lower end, the charge head  24  is caused to be lowered. It will be recognized that many alternate forms of control element may be substituted for the rocker switch chosen for purposes of disclosure. Such alternate controls include, but are not limited to pushbutton switches, dials (i.e., rotary controls), joysticks, touchscreen panels, or any other type of manual controller. Manual control  70  may control electrical circuits, not shown, to effect delivery of hydraulic fluid to hydraulic cylinder  32 . Such circuits are believed to be well known to those of skill in the art and are not further described herein. 
     A second type of manual control included upon maneuvering handle  64  is a safety arrangement known as a “dead man” switch system. A first dead man switch  72  and a second dead man switch  74  are disposed on opposite sides maneuvering handle  64 . Unless both dead man switches  72 ,  74  are activated by respective left and right hands of an operator, the hydraulic assist system for maneuvering charge head  24  remains disabled. This arrangement further ensures the use of both hands of the operators on maneuvering handle  62 . First and second dead man switches  72 ,  74  may be implemented as mechanical switches or other types of electrical sensors such as a capacitive sensor to sense the presence of both user hands on maneuvering handle  64 . Circuitry for implementing such dead man arrangements is also believed to be well known to those of skill in the art and is not further described herein. 
     Charge head  24  may include an alignment element disposed to assure that the charge head  24  effectively engages the array of charging electrodes  77  in a predetermined direction and orientation relative to the array of charging electrodes  26 . The alignment element may comprise at least two pins  76 , each having a tapered blunt exposed end  78 . If desired, pins  76  may be tapered along all or a significant extent of their length and not just at their exposed ends  78 . Pins  76  may mate with corresponding holes, not specifically identified, formed proximate the array of charge receiving electrodes  77  of motor vehicle  91 . 
     Referring now also to  FIG. 3 , there is shown a front elevational, schematic view of the vehicle charging system  10  and revealing additional elements and details thereof. 
     Charge head  24  is shown in a position approaching an array of charge receiving electrodes  77  of motor vehicle  91  with which the charge receiving electrodes  77  are associated. The array of charge receiving electrodes  77  may be similar to that described in the related, included by reference application Ser. No. 12/657,533, now issued as U.S. Pat. No. 8,174,238, entitled CHARGING CONTACT ARRAY FOR ENABLING PARALLEL CHARGING AND SERIES DISCHARGING OF BATTERIES, filed concurrently herewith. 
     Charging electrode system  10  includes a DC electrical power source  80 , which may comprise transformer and converting apparatus for transforming electrical power supplied from an electrical utility as relatively high voltage AC current to relatively low voltage DC. Alternatively, the DC electrical power source  80  may comprise a motor/generator arrangement, a fossil fuel powered generator, or any other DC power source currently known, or yet to be devised. It will be recognized that DC power source  80  may include appropriate circuit protection devices (e.g., fuses, circuit breakers, ground fault interrupters (GFIs), etc.), not specifically identified. Such circuit protection devices are also well known to those of skill in the art. Appropriate DC power sources are well known to those of skill in the art and, consequently, are not described in further detail herein. 
     Charging electrodes  26  of the charge head  24  may be connected to the DC electrical power source  80  by suitable electrical conductors  82 . Conductors  82  are typically insulated stranded, conductors and may be implemented as multiple cables to provide the required current carrying capacity. Conductors  82  typically extend through the interior of or along the exterior of tower  14  and boom  18 . 
     A current sensor  86  and/or a voltage sensor, not shown, form part of a charge monitoring system disposed to sense progress of charging of batteries  84 . The monitoring system may determine and, optionally, report the state of charge of the battery  84 , the rate of charge, and also may indicate the completion of charging. Completion of charging may be annunciated locally (i.e., near charge head  24 ) by an annunciator  88  which may be visual, auditory, or both visual and auditory. In addition or in lieu of a local annunciator  88 , upon completion of charging, a wireless signal may be generated to communicate this information to a user remote from vehicle  91  and charge head  24 . Communications apparatus  90  generates a wireless signal that may, for example, communicate with a cellular telephone, a personal data assistant (PDA), a beeper, or a dedicated communications device adapted solely to receive a signal, none of which are shown, from communication apparatus  90 . Remote signaling may be utilized to advise a vehicle operator, not shown, who may, for example, have left his or her motor vehicle  91  to be charged in his or her absence. Devices and technology for such remote communication is believed to be well known to those of skill in the art and is, consequently, not further discussed herein. 
     The monitoring system may also monitor the temperature of battery  84  or any other part of the charging system between the charger or charging device and the vehicle battery group being charged by the charging electrode system  10 . For example, the temperature of cables, cable connections, or the charging contacts may be temperature monitored. A temperature sensor  92  in conjunction with a feedback system  94  transmits temperature information to the monitoring system. The monitoring system may then take appropriate action, such as reducing the rate of charge or even disconnecting battery  84  from power responsively to battery temperature by operating a controller  96  arranged to control power to the conductors  82  of the charging circuit. Of course, the controller  96  may alternately be arranged to control inputs of AC power to the DC electrical power source  80  rather than regulating outputs of DC power. Devices, systems and technology for temperature monitoring and/or controlling current responsive to temperature data are believed to be well known to those of skill in the art. Consequently, not further description thereof is provided herein. 
     The charging electrode system  10  may optionally include a security system to sense the identity of the motor vehicle  91  connected to the charging electrode system  10 . A radio frequency identification (RFID) transponder  98  may interrogate a radio frequency identification tag  100  located onboard the motor vehicle  91 . The RFID transponder  98  may be utilized for several purposes. It may, for example, determine an optimum charging rate from information supplied by the vehicle manufacturer. It might interrogate RFID tag  100  for a vehicle identification number (VIN) and automatically check a database of stolen vehicles. If the vehicle appears to be stolen, a disabling signal could be sent to the vehicle  91  and appropriate authorities (e.g., the police) may be notified. The system may also be utilized by authorities if the vehicle were to be stolen during the charging operation. Systems for accomplishing such monitoring and notification tasks are believed to be known to those of skill in the art and are not discussed in more detail herein. 
     A further safety feature of the novel charging system  10  of the invention is that the movement of charging head  24  into contact with charge-receiving contacts  77  within motor vehicle  91  is that the vehicle&#39;s motor, not shown, is completely disabled. 
     It is contemplated that one or more charging electrode systems such as the charging electrode system  10  may be utilized in a commercial recharging station for electrically powered vehicles. Such a station may offer both electrical recharging services and also may sell combustible fuels. Because it is contemplated that the charging electrode system  10  of the invention is usable in a commercial recharging facility (i.e., an electric “gas station”), not shown in its entirety, the charging electrode system  10  may include a payment acceptance apparatus to receive payment for electrical energy delivered by charging electrode system  10 . The payment acceptance arrangement may inhibit delivery of electrical power until payment is made. The payment acceptance arrangement may comprise a conventional point of sale processor  102  for reading electronic payment cards such as debit cards and credit cards, not shown. Point of sale (POS) equipment and systems are believed to be well known to those of skill in the art and are not further discussed herein. 
     Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
     Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.