Abstract:
An electrical system for low-power charging of personal electronic devices is made available at each passenger seat in a vehicle using wireless power technology. Alternating current is delivered by conductors behind the sidewall panels or under the floor of the vehicle body to the passenger area. Electrical power is transferred from these conductors using transmit coils attached outboard of the sidewall panels or below the floor to receive coils attached to passenger seats near the transmit coils. The electrical current induced in the receive coils is made available via electrical power charging circuits at a convenient location for each seat via conventional charging ports. Transmit and receive coils are designed and configured to permit different seating configurations without the need for rewiring by placement and design of larger transmit and receive coils or by using track-mounted transmit and receive coils or a combination of these.

Description:
TECHNOLOGICAL FIELD 
       [0001]    The present disclosure relates generally to the field of wireless electrical power. More specifically, the present disclosure relates to providing wireless electrical power to passenger seats in vehicles. 
       BACKGROUND 
       [0002]    Wireless technology involves using a first electrical current in a first conductor to generate a magnetic field that is then used in turn by a second conductor to generate a second electrical current. Coils are used to more efficiently couple the first conductor to the second conductor. A transmit coil on the end of the first conductor and a receive coil on the end of the second conductor can be designed and positioned to transfer power efficiently. The receive coil can be connected electrically to an electrical charging device. 
         [0003]    Transferring electrical power wirelessly is known. Using wireless power transfer to charge or recharge portable electronic devices is also known. The elimination of the direct physical connection obtained in wireless power transfer avoids the problem of plug-socket incompatibility. It also reduces the need for the receive coil to be in a precise location. 
         [0004]    Transferring power for charging devices and other purposes and has been extensively studied. See, for example, U.S. Pat. No. 8,963,488, U.S. Pat. No. 8,957,548, U.S. Pat. No. 8,946,938, U.S. Pat. No. 8,816,633, U.S. 8,035,255, U.S. Pat. No. 7,825,543 and U.S. Pat. No. 7,741,734, all of which are incorporated herein in their entirety by reference. 
         [0005]    Providing electrical power to operate and charge personal electronic devices, such as cell phones, pad-type computers, tablet computers, and gaming devices in a vehicle poses additional challenges. Wireless power operates most effectively at close range so there is still a requirements for wiring to deliver electrical current and for the transmit coil to be close to the receive coil. Consequently, it may be simpler to wire a vehicle for charging electrical outlets during its manufacture. In buses and passenger aircraft, where there are typically many seats, the requirements for wiring each seat are multiplied to the point where the cost of the wire and the labor to install it and even the weight of the wiring becomes an issue. 
         [0006]    Moreover, seating in vehicles may be reconfigured after its initial configuration. Replacing seats in first class of an aircraft with more coach seating or adding or removing a row of seats and adjusting the remaining seat row accordingly alters the seat pitch, that is, the distance between rows. Allowing for reconfiguration of seating in a hard-wired or wireless power mode in such a vehicle is much more complicated than in a fixed-seat vehicle. 
         [0007]    A system for providing electrical charging power to each passenger seat of a vehicle that overcomes these issues would be of advantage. 
       BRIEF SUMMARY 
       [0008]    The present disclosure describes an electrical system for low-power wireless charging that is available at each passenger seat in a vehicle. Electrical current is delivered by conductors located behind the sidewall panel or under the floor of the vehicle body along the sides of the passenger area. Power is transferred from those conductors by transmit coils carried by the sidewall panel or by the floor to receive coils located between the seat and the wall panel or floor and then made available to a convenient location at each seat for use by passengers, such as through conventional uniform serial bus (USB) ports. Transmit and receive coils are designed, located, and configured to permit changes in the seating configuration without rewiring. 
         [0009]    By building in flexibility in the locations of the transmit and receive coils that complements the spatial flexibility inherent in wireless power transfer, the goal of electrical charging power for each seat in a reconfigurable vehicle is met. Flexibility is provided by coil geometric design, number, location, and by movable transmit and receive coils, or a combination of these. 
         [0010]    According to an aspect of the disclosure, a power supply for the vehicle produces an electrical current that is carried into the interior of the vehicle to the passenger seating area using electrical conductors running behind a wall panel or under a floor of the interior where passenger seats are located. Transmit coils are carried by the wall panels or mounted under the floor near the seats. Receive coils are positioned between the transmit coils and the seats so that electrical current may be induced by the transmit coils in the receive coils. The received electrical current is conducted to an electrical power charging outlet located conveniently for each seated passenger where it is made available via standard direct current charging plugs for use in charging and recharging personal electronic devices. 
         [0011]    An aspect of the disclosure is that the transmit coil may be located under the floor or behind the wall panel and the receive coil may be located on the floor above the transmit coil, on the opposite side of the wall panel from a transmit coil, or attached to the end seat of a row of seats when the end seat is close enough to the wall panel-mounted transmit coil. The receive coil may alternatively be located under an end seat to be close to a transmit coil mounted under the floor or on a wall panel. 
         [0012]    Another aspect of the disclosure is that the transmit coil may be horizontally movable in the event the receive coil is attached to the outboard seat of a row of seats and the seat pitch is shortened or lengthened. 
         [0013]    Yet another aspect of the disclosure is that the transmit coil may be designed to be longer in the horizontal direction in the event of a pitch change in a seat having a seat-based receive coil so that the perpendicular spacing between the transmitting and receive coils does not change when the position of the seat is moved forward or backward. 
         [0014]    An aspect of the disclosure is that the electrical power line may support plural spaced-apart transmit coils in the event there are plural spaced-apart seats or rows of seats to provide wireless charging power transfer to each seat or row of seats. 
         [0015]    An aspect of the disclosure is that the electrical charging circuit may produce, for example, five volts DC for charging power through a standard charging port such as a universal serial bus port. 
         [0016]    An aspect of the disclosure is that the vehicle may be an aircraft, an automobile, a bus, a watercraft or a truck having passenger seating. 
         [0017]    Another aspect of the disclosure is a method for providing electrical power to a seat in a vehicle by attaching a transmit coil to a wall panel of the vehicle, attaching a receive coil between the transmit coil and a seat in the vehicle, and attaching an electrical power charging circuit to the seat in the vehicle. Then, by energizing the transmit coil with a first electric current from a source of electric current, a second electric current is induced in the receive coil, and the induced electric current is conducted to the electrical power charging circuit for the user to use in charging a personal electronic device. 
         [0018]    Yet another aspect of the disclosure is attaching a sladable transmit coil to the wall panel so that, if a receive coil is attached to a seat and the seat is moved, the transmit coil can be moved to the new location of the receive coil without rewiring. 
         [0019]    Other aspects of the disclosure will be apparent to those skilled in the art of wireless power from a careful reading of the Detailed Description accompanied by the following drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]    Having thus described variations of the disclosure in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein: 
           [0021]      FIG. 1  is a cross-sectional view of a vehicle with a row of seats and a wall-mounted power transfer system, according to an aspect of the disclosure; 
           [0022]      FIG. 2  is a cross-sectional view of a vehicle with a row of seats and a floor-mounted power transfer system, according to an aspect of the disclosure; 
           [0023]      FIG. 3  is a top, cross-sectional view of a portion of the passenger area of a vehicle with rows of seat having two different seat pitches to show the adjustability of a wall-mounted power transfer system in accommodating the two different seat pitches; 
           [0024]      FIGS. 4A and 4B , respectively, are side views of two seats in a passenger vehicle before and after the modification of the seat pitch having long transmit coils that can accommodate the increase in the seat pitch without rewiring, according to an aspect of the disclosure; 
           [0025]      FIG. 5A and 5B  show top cross-sectional and side views, respectively, of a wall-mounted transmit coil carried by a track on the inboard side of wall panel to permit horizontal adjustment of the transmit coil, according to an aspect of the disclosure; 
           [0026]      FIG. 6A and 6B  show top cross-sectional and side views, respectively, of a wall mounted transmit coil carried in a track on the outboard side of the wall panel to permit horizontal adjustment of the transmit coil, according to an aspect of the disclosure; and 
           [0027]      FIG. 7A and 7B  show seat side-mounted and seat bottom-mounted tracks, respectively, with movable receive coils according to an aspect of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0028]    Disclosed herein is a system and method for providing direct current charging power to an electric charging device proximate to the seats of a passenger vehicle. The disclosed system enables vehicular electrical power to be transferred wirelessly to a passenger seat from a transmitting coil behind or on vehicle wall panels or below the vehicle&#39;s floor, which thereby reduces wiring requirements and enables seat replacement or reconfiguration without disconnecting and reconnecting wires. Moreover, by design of transmit and receive coils, it allows seats to be located at different pitches, an aspect important in vehicles where seats are configured in different ways across aircraft of the same type or reconfigured in the same aircraft from time to time. A row of seats may contain plural seats that are managed as a unit. One coil can receive power for the row that can then be delivered to a charging port at each of the seats via electrical conductors embedded in the row. Accordingly, the present system and method reduces wiring costs, wiring installation time and costs, and the weight of wiring in providing a recharging capability to passengers. 
         [0029]    The term electrical charging device refers a device that has a charging port that receives a plug and delivers via that plug direct current at a voltage suitable for operating or charging a personal electronic device, typically five volts DC. The electrical charging device may receive alternating electrical current and rectify it, and may condition the current so as to provide steady, controlled voltage direct current. The plug, which is a feature of the disclosure, may be, for example, a universal serial bus (USB) plug but may be a different plug configuration. 
         [0030]    The term personal electronic device includes consumer products that are battery operated and rechargeable, and include cell phones, pad type computers, palm top computers, gaming devices, and devices for playing music such as MP3 and MP4 format players, as well as subsequently developed portable, personal devices for communication and entertainment. 
         [0031]    Referring now to the drawings,  FIG. 1  is a cross-sectional view of a vehicle  10 , here showing a portion of an aircraft. Vehicle  10  has a body  14  with a floor  18  and a wall panel  22  and may also have a window  26  and an overhead compartment  30  for personal items of passengers. Vehicle  10  may have seats  34 A,  34 B,  34 C, arranged in a row  38 , which seats may be fabricated as one unit. Each seat  34  has a back  42 , a seat cushion  46 , arm rests  50 , and a frame  54 . 
         [0032]    In vehicle  10 , as shown in  FIG. 1 , a transmit coil  58  is attached to the outboard side of wall panel  22  and electrically connected to an electrical conductor  60  carrying electrical current. Attached to the outboard side of seat  34 A is a receive coil  62 . Receive coil  62  responds to the magnetic field generated by transmit coil  58  by producing an electric current that is electrically conducted to an electric charging device  66  and provided for charging personal electronic devices through a standard charging port (not shown) such as a USB charging port. The power source may be an alternating power source, in which case, it may be rectified before delivery to the charging port. Rectification may take place at the source prior to transmission by the transmit coil  58  or after receipt by the receive coil  62 . 
         [0033]    In  FIG. 2 , a different arrangement of a transmit coil  58 ′ and receive coil  62 ′ are shown. Otherwise, vehicle  10  is the same as shown in  FIG. 1 . In  FIG. 2 , transmit coil  58 ′ is attached to the underside of floor  18  and receive coil is located on floor  18  but may be attached to seat frame  54 . Transmit coil  58 ′ and receive coil  62 ′ need to be close enough to transfer power, and the spacing and intervening materials must be such that the magnetic field formed by transmit coil  58 ′ and that is inducing an electric current in receive coil  62 ′ is adequate for charging personal electronic devices. Designing transmit and receive coils is well known and well understood by those skilled in the art of wireless power transfer, and charging systems exist for recharging objects ranging from personal electronic devices to electric cars. 
         [0034]    Receive coil  62 ,  62 ′ may be attached to row  38  so that moving and removing row  38  moves and removes coil  62 ,  62 ′ and therefore simplifies reconfiguration of vehicle  10 . 
         [0035]      FIG. 3  shows a top view of a portion of vehicle  70  showing two groups of rows  74  of seats  78 , namely a first group  82  with a wider seat pitch and a second group  86  with a narrower seat pitch.  FIGS. 4A and 4B  show a pair of seats  78  from the side, one in back of the other in a first pitch ( FIG. 4A ) and in a second pitch ( FIG. 4B ). Power cords  90  runs along the two sides of the passenger area of vehicle  70  to deliver a first electric current. A power source  118  with a circuit breaker provides the electric current to power cords  90 . 
         [0036]    At intervals along power cords  90  are transmit coils  98  on the inside of walls  102 . On seats  78  are receive coils  110  that respond to the magnetic fields generated by transmit coils  98 , which carry first electrical current, by generating a second electrical current. Second electrical current is received by charging device  114  which is in electrical connection with receive coils  110 . Transmit coils  98  are larger than receive coils  110 , and in particular have a major dimension parallel to walls  102  that is greater than the dimension of receive coils  110 , so there is a range of possible positions for receive coils  110  that will still enable them to be aligned with transmit coils  98 , that is, close enough to able to receive transferred power. Therefore, the spacing of rows  74  may be varied without the need to change the locations of transmit coils  98  with respect to receive coils  102  because transmit coils  98  are larger. 
         [0037]      FIGS. 4A and 4B  show the change in pitch possible without a change in wiring or placement of transmit or receive coils  124 ,  128 , respectively, because the transmit coil  124  is larger than receive coil  128 .  FIG. 4A  shows seat row  126  with a first, smaller pitch and  FIG. 4B  shows seat row  126  with a second, larger pitch, achieved by moving the left row  126  rearward. Despite the increase in pitch, receive coil  128  in row  126  remains aligned with transmit coil  124  in both front and back rows  126  in both  FIGS. 4A and 4B  because transmit coil  124  is designed to be larger so receive coil  128  remains close enough transmit coil  124  for the second current to be induced in receive coil  128  from the first current in transmit coil  124 . 
         [0038]    Alternatively, receive coil  128  may be larger than transmit coil  124  or both transmit  124  and receive coils  128  may be made wide for greater flexibility in selecting the pitch of rows  126  while still having transmit and receive coils  124 ,  128  overlap. In addition, more transmit coils  124  could be provided than receive coils  128  for an additional source of flexibility in pitch selection. 
         [0039]    In  FIGS. 5A and 5B , there is illustrated a top, cross-sectional view of a movable wall panel-mounted transmit coil  130  attached to an electrical conductor  132 . Transmit coil  130  is slidably attached to a track  134  that is mounted to the exterior of a wall panel  138 . Transmit coil  130  is able to slide horizontally to provide flexibility in moving it closer to a receive coil (not shown in  FIGS. 5A or 5B ). To facilitate horizontal movement, slack is provided in wires  142  inside track  134 , which wires  142  run to an electrical conductor  132 . A locking mechanism may be provided to prevent unauthorized movement of the transmit coil  130 . 
         [0040]    In  FIGS. 6A and 6B , a transmit coil  150  is connected to an electrical conductor  152  and is shown slidably attached to a track  154  that is in turn attached to the outboard side of a wall panel  158  but which is accessible through a slit  162  in panel  158 . A peg  166  is attached to transmit coil  150  and that extends through slit  162  or mat be accessed through  162  using a tool, such as an Allen wrench (not shown) to adjust the horizontal position of transmit coil  150 . This embodiment allows transmit coil  150 , positioned on the outboard side of panel  158 , to be accessed by technicians from inside the cabin. 
         [0041]      FIGS. 7A and 7B  illustrate passenger seat  170  with a track  174  attached to the outboard side of seat  170  in  FIG. 7A  and to the outboard side of frame  176  under seat  170  in  FIG. 7B . Seat  170  carries a receive coil  178  mounted to track  174  so that it may be slid horizontally to align receive coil  174  with the nearest transmit coil (not shown). Receive coil  178  is wired to an electronic charging device  182 . In a similar manner, receive coil  178  may alternatively be placed in a floor-mounted track  174 . Receive coil  178  may be locked once in position or otherwise secured to prevent tampering. 
         [0042]    When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Although this disclosure has been described with respect to specific embodiments, the details of these embodiments are not to be construed as limitations.