Abstract:
A wheeled transport device, such as a piece of luggage configured to be manually wheeled by a pedestrian user, in provided with an electrical generator operably coupled to a rolling wheel of the device and configured to produce electrical energy as the user wheels the device along a supporting surface. The generator provides power to charge a battery contained within the device and/or one or more electrical appliances being transported within the device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/599,360, filed Aug. 6, 2004 and entitled “Electrical Power Generation,” which is incorporated by reference herein. 
     
    
     TECHNICAL FIELD  
       [0002]     This invention relates to luggage and other personal, totable or wheeled containers for transporting personal effects.  
       BACKGROUND  
       [0003]     Business travelers are frequently found in airports or other public spaces, hunting for available electrical power outlets to power or recharge portable electronic equipment, such as laptops, cell phones and the like, or hovering around such outlets waiting for rechargeable equipment to fully recharge, wasting otherwise useful time.  
         [0004]     There is frequently a need for electrical power when such outlets are unavailable.  
       SUMMARY  
       [0005]     In several aspects, this invention features a wheeled suitcase, luggage or other personal, totable or wheeled containers for transporting personal effects, provided with an electrical generator coupled to at least one of its rolling wheels, either directly or indirectly, for transforming a portion of the energy supplied by the user in pulling or pushing the device into usable electrical energy.  
         [0006]     According to one aspect of the invention, a wheeled transport device configured to be manually wheeled by a pedestrian user includes a main body defining a compartment therein for containing goods to be transported, a handle attached to the main body and manually graspable by the pedestrian user while walking, at least one wheel disposed at a lower end of the main body and secured to the body for rotation along a surface upon which the user is walking, and an electrical generator operably coupled to the wheel and configured to produce electrical energy as the user wheels the device along the surface.  
         [0007]     In many embodiments, the device also includes an electrical power outlet secured to the main body, electrically connected to the generator, and exposed for connection of an electrically powered device by the user. In some cases the outlet is accessible from within the main body compartment, such as for plugging in luggage contents for charging.  
         [0008]     In some cases, the device further includes a battery secured to the main body and electrically connected to the generator for storage of electrical energy from the generator.  
         [0009]     In some configurations, the generator is operably coupled to the wheel by a flexible cable. In some other configurations, the generator contains an armature directly coupled to, and coaxial with, the wheel. In some instances, the generator is operably coupled to the wheel through a pair of engaged gears, or is driven by a roller directly engaging a surface of the wheel. In the latter case, the device may also include a spring biasing the roller against the wheel surface. Thus, the generator can be attached to the drive wheel in many ways, including but not limited to: a rigid axle that rotates with the wheel, a flexible shaft, a direct drive gear, or a wheel that runs directly from the rotating wheel of the transport device. Alternatively, the wheel itself may be configured as a generator, with the hub assembly of the wheel acting as the rotor of the generator and the outer revolving wheel the windings of the generator.  
         [0010]     In many advantageous embodiments, the device is a piece of wheeled luggage, such as a wheeled suitcase. However, other sorts of wheeled transport devices, such as carts or wheelbarrows, are contemplated.  
         [0011]     In some cases, the main body includes a hinged lid for accessing contents contained within the compartment.  
         [0012]     An on/off switch may be provided, the switch manually operable to selectively open the windings of the generator to disable power generation and reduce drag on the rolling wheel when electrical power is not needed.  
         [0013]     Another aspect of the invention features the above-described wheeled transport device in combination with a personal electrical appliance contained within the compartment and electrically connected to the generator.  
         [0014]     Another aspect of the invention features a method of powering personal electrical appliances. The method includes providing the above-described wheeled transport device, electrically connecting a personal electrical appliance to the generator of the device, and rolling the device along a surface to generate and deliver electrical power to the connected appliance.  
         [0015]     Various aspects of this invention can provide a complimentary function to the transport device, by transforming user energy into useful electrical energy. This additional function is particularly useful to business travelers when incorporated into wheeled luggage, but can find utility in other areas, such as operator-pulled machinery and the like.  
         [0016]     The generator may directly power a device, or may charge an onboard battery, so that the device may operate while the cart is at rest.  
         [0017]     This invention can make use of untapped energy produced by a human when pushing or pulling a suitcase or wheeled cart. The energy needed to power or charge many portable electronic devices is typically only a small fraction of the energy needed to move the wheeled cart. The addition of an appropriate generator/charger to a human-powered push/pull cart would thus require a negligible amount of extra energy from the user. This extra energy could be manually or automatically adjusted to the user&#39;s preferences. Tapping into this energy can allow rechargeable personal accessories to be kept in a charged state without requiring the user to find an electrical outlet in a public place such as an airport, and then waiting for the device to recharge.  
         [0018]     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0019]      FIG. 1  illustrates a pedestrian pulling a wheeled suitcase.  
         [0020]      FIG. 2  is a perspective view of a first wheel-driven electrical generator system, with a flexible drive shaft.  
         [0021]      FIG. 3  is a cross-sectional view of the system of  FIG. 2 , showing the drive mechanism.  
         [0022]      FIG. 4  is a perspective view of a second wheel-driven electrical generator system, with a direct connection between rotating axle and generator.  
         [0023]      FIG. 5  is a cross-sectional view of the system of  FIG. 4 , showing the drive attachment.  
         [0024]      FIG. 6  is a perspective view of a third wheel-driven electrical generator system, with a gear coupling.  
         [0025]      FIG. 7  is a cross-sectional view of the system of  FIG. 6 , showing the drive mechanism.  
         [0026]      FIG. 8  is a perspective, partial cutaway view of a first wheel-driven electrical generator system, with a generator driven from the outer surface of the wheel.  
         [0027]      FIG. 9  is a cross-sectional view of the system of  FIG. 8 .  
         [0028]      FIG. 10  is a perspective view of an embodiment of a wheel assembly adapted to provide electrical energy.  
         [0029]      FIG. 11  is a cross-sectional view of the wheel assembly of  FIG. 10  taken along line  11 - 11 .  
         [0030]      FIG. 12  is a cross-sectional view of the wheel assembly of  FIG. 10  taken along line  12 - 12 .  
         [0031]      FIG. 13  is a cross-sectional view of an embodiment of a wheel assembly adapted to provide electrical energy. 
     
    
       [0032]     Like reference symbols in the various drawings indicate like elements.  
       DETAILED DESCRIPTION  
       [0033]     Referring to  FIG. 1 , a wheeled suitcase  8  includes a pair of wheels  10  upon which the suitcase rolls when pulled by a handle  11 . Suitcase  8  also includes an electrical generator  12  coupled to at least one of the rolling wheels  10 , such that electrical energy is generated as the suitcase is rolled upon surface  14 . The generator may directly power a device, such as a personal electronic device  9  contained within the suitcase, or may charge an onboard battery  11 , for operating electronic devices or powering other devices, such as suitcase-mounted displays or lighting, while the suitcase is at rest. Preferably, either the generator or battery is electrically connected to an electrical outlet (not shown), such as a DC outlet exposed either on the inside of the suitcase or on an external surface of the suitcase, into which electrical devices can be plugged for powering or charging. Such an outlet may include a manually operable voltage and polarity selector. A small inverter may also be included, to supply AC power. A switch  13  on the suitcase handle is manually operable to selectively short the windings of the generator to disable power generation and reduce drag on the rolling wheel when electrical power is not needed.  
         [0034]     Referring to  FIG. 2 , in one embodiment a single wheel  10  of the wheeled suitcase rotates with axle  16  within axle housing  17  and transfers rotational motion to generator  12  along flexible shaft  18 . The generator  12  is mounted to the frame or other attachment point on the 2-wheeled cart or suitcase using generator mounting bracket  22 . When the cart is in motion, the wheel  2 , the flexible shaft  18  and the windings of generator  12  will rotate, producing electrical potential across generator output leads  20 . These leads may be connected to an electric device through appropriate power conditioning circuitry (not shown) to power or charge the device.  
         [0035]     Referring also to  FIG. 3 , rotational energy from wheel  10  will transfer to axle  16  via drive key  26 , then through connecting pin  28  to flexible shaft  18 , driving generator input shaft  30 , which rotates the generator windings. The axle rotates upon bearing  32  and the thrust load is absorbed by retaining clip  34 , both of which reside in housing  17 . When the generator windings are rotating, an electric potential is produced between generator output leads  20 .  
         [0036]     Referring next to  FIGS. 4 and 5 , in a second embodiment a hollow housing  36  contains generator  12  and an axle  16   a . Axle  16   a  connects to wheel  10  and transfers the rotation of the wheel to the generator  12 . When the cart is in motion the wheel  10  will rotate, and this rotational energy will transfer through drive key  26  to axle  16   a , to generator input shaft  30 , which rotates the generator windings. Axle  16   a  is supported on appropriate bearings, such as a first bearing (not shown) between the axle and axle housing near the wheel, and a second bearing (not shown) within generator  12 . When the generator windings are rotating, an electric potential is produced between generator output leads  20 .  
         [0037]     Referring next to  FIGS. 6 and 7 , in a third embodiment rolling wheel  10  drives the generator  12  through a pair of gears  44   a  and  44   b , such as spur or helical gears or friction drive wheels. Wheel axle  16   b  is supported in housing  40  on journal bearings  42  and is keyed to both wheel  10  and gear  44   b . Generator shaft  30  is directly coupled to gear  44   a  for rotation, and is supported on bearings within the generator. The gear combination can be used to adjust the ratio of the rotational velocity of the wheel  10  and the windings of generator  12 .  
         [0038]     Referring next to  FIGS. 8 and 9 , in a fourth embodiment rolling wheel  10  drives the generator  12  directly, by means of frictional engagement with the rolling wheel surface. Wheel  10  rotates on bearing  52  around stationary axle  50 , which may be pressed into housing  56 . Roller  54  rests on wheel  10  and is rotationally fixed to generator input shaft  30 . Pressure is applied to the roller  54  and wheel  2  interface by compression spring  58 , which applies a force between housing  56  and generator  12 . This force is transferred through generator input shaft  30  to the roller  54 . When the wheel  10  rotates, the roller  54  also rotates at a velocity proportional to the wheel velocity, as determined by the ratio of the effective rolling diameters of roller  54  and wheel  10 .  
         [0039]     The generator  12  discussed herein may be utilized in a reverse mode, drawing power from an onboard battery and functioning as a motor to provide propulsion through the rolling wheel  10 .  
         [0040]     In some embodiments, the wheel assembly can function as a generator. Referring to  FIGS. 10-12 , for example, a wheel assembly  100  includes a wheel  110  that is rotatably positioned about an axle  116 . Axle  116  can be rigidly attached to the housing of a luggage device in order to allow the luggage device to be rolled along a surface as wheel  110  rotates about axle  116 . Axle  116 , as shown in  FIG. 11 , includes an inner portion  118 , an outer portion  120 , and an insulating portion  122  that physically separates inner and outer portions  118  and  120  from one another. Inner and outer portions  118  and  120  can be formed of any of various electrically conductive materials. Examples of electrically conductive materials include copper, aluminum, silver, and gold. Insulating portion  122  can be formed of any of various insulating materials, such as thermoset plastics, polymer dilectrics, ceramics, glasses, silicates (e.g., quartz), and/or rubbers. The interior ends (e.g., the ends nearest the luggage body) of each of inner and outer portions  118  and  120  include electrical leads (e.g.,. electrical wires)  126  that can connect inner and outer portions  118  and  120  of axle  116  to an electronic device and/or a power source (e.g., a battery) associated with the luggage device.  
         [0041]     Referring to  FIGS. 11 and 12 , a field magnet  124  is positioned within axle  116 . Field magnet  124  is a ring shaped magnet that includes multiple slots  125  extending radially from a center point of the magnet. Slots  125  can divide magnet  124  into multiple (e.g., four) interconnected segments. Field magnet  124  can be formed of any of various magnetic materials, such as Neodymium Iron Boron (NdFeB or NIB), Samarium Cobalt (SmCo), Alnico Ceramic, and/or Ferrite.  
         [0042]     Wheel  110  includes windings  128  that are arranged in a ring-shaped structure and configured to extend circumferentially about the rotational axis of wheel  110 . Multiple metal bands  127  extend around windings  128 . Metal bands  127  are circumferentially spaced apart about the ring structure-shaped structure of windings  128 . When wheel  110  is positioned around axle  116 , as shown in  FIGS. 11 and 12 , windings  128  and metal bands  127  surround magnet  124 . Windings  128  can be formed of one or more materials, such as copper, aluminum, silver, and/or gold. Metal bands  127  can be formed of any of various high permeability metals, such as steel.  
         [0043]     Brushes  130  are positioned within cavities formed in wheel  110 . Brushes  130  are electrically connected to windings  128 . Cavities are open at an inner diameter of wheel  110  such that brushes  130  are exposed to an outer surface of axle  116 . Brushes  130  can protrude from the opening of the cavities such that brushes  130  contact the outer surface of axle  116 . Brushes  130  can be formed of any of various materials, such as brass, carbon-amorphous, graphite, copper, copper graphite, copper tellurium, copper tungsten, copper zirconium diboride, gold, electrographite, metal graphite, molybdenum, palladium, platinum, plated base metal, resin bonded graphite, silver, silver copper, silver cadmium oxide, silver graphite, silver molybdenum, silver nickel, silver tin oxide, silver tungsten, silver tungsten carbide, tungsten, tungsten carbide, and/or alloys of these materials.  
         [0044]     During use, the user pushes or pulls the luggage device, causing wheel  110  to roll along the surface on which the user is walking. While the luggage device is pushed or pulled along the surface, wheel  110  rotates about axle  116 , which causes windings  128  to rotate about magnet  124 . As windings  128  rotate about magnet  124 , an electric potential is produced between electrical leads  126 . Alignment of metal bands  127  with the separated segments of magnet  124  can, for example, increase the magnetic flux relative to the magnetic flux that is generated when the separated segments of magnet  124  are aligned with slots  125 . Consequently, an alternating magnetic flux is produced, which can induce an alternating voltage in windings  128 . The voltage can be transferred from windings  128  to axle  116  via brushes  130 . The voltage generated by this process can be transferred via electrical leads  126  (connected to axle  116 ) to the electronic device or power source of the luggage device. Consequently, the electronic device and/or the power source of the luggage device can be powered as the user pulls or pushes the luggage device along the ground surface.  
         [0045]     While magnet  124  was described as being positioned within axle  116  and windings  128  were described as being positioned within wheel  110  in the wheel assembly of  FIGS. 10-12 , other arrangements are possible. As shown in  FIG. 13 , for example, windings  128  can be positioned within axle  116  and field magnet  124  can be positioned within wheel  110 . As wheel  110  is rotated about axle  116 , an alternating voltage is induced in windings  128 . Electrical leads  126  are connected to windings  128  such that the voltage induced in windings  128  can be transferred to an electronic device or a power source.  
         [0046]     In some embodiments, the alternating voltage is rectified to produce a direct voltage (DC voltage). Multiple windings can be oriented axially to one another to increase the power generated by the generator and/or reduce ripple in a rectified direct voltage waveform.  
         [0047]     Another example of a wheel-driven generator can be found in a provisional U.S. patent application filed concurrently herewith and entitled “SUSPENSIONS FOR WHEELED TRANSPORT DEVICES,” the entire contents of which are incorporated herein by reference.  
         [0048]     Wiring between the generators described herein, any included batteries, on-board electrical devices and/or outlets can be permanently routed within the walls of the suitcase, as needed.  
         [0049]     A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims.