Abstract:
The creative product relating to a “power bicycle&#39;s dual-drive device”, which contains a pedal-driven part, a motor-driven part, a gearing mechanism, and a controller; the electric motor axis of the motor-driven part has a drive-gear and the relay-gear, the first and second transmission member connect the gear plate with the relay-gear and the drive gear with the transmission gear disc respectively, through the dual-drive device, either alone or mixed selection; by the driven pedal to control the electric driven motor and to drive the driven gear for operation, to produce large torque output in order to drive the transmission gear disc, to correspond with the transmission to control the second transmission member to the transmission gear disc of different outside diameters for changing the gear, for satisfying the riders to choice their own mode of laborsaving or exercise demand in different terrains.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of Foreign Application of Taiwan, Republic of China (Taiwan New Model Application No. 09201110), filed on Jan. 21, 2009. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    This invention relates to a motorized vehicle, specifically related to a dual-drive device (dual-drivetrain) of the motorized vehicle, more specifically related to the dual-drivetrain that simultaneously transmits both electric and pedal driven power so that the vehicle can use an attached motor to assist with pedaling. The dual-drivetrain can be applied to various kinds of pedal-driven, human-powered vehicle, such as bicycles, tandem bicycle, tricycles, as well as mopeds. 
         [0004]    2. Description of Related Art 
         [0005]    With an increasing awareness of saving energy and minimizing carbon dioxide emission, human-powered and pedal-driven vehicles (e.g., bicycles, tricycles) have become quite popular transportation in the world. In addition to reducing fossil fuel consumption and environmental friendly, pedaling is a good exercise to achieve body&#39;s fitness exercise. 
         [0006]    At present, the pedal-driven vehicle can be divided into two categories: one is a traditional pedal driven vehicle (e.g., the traditional bicycle); the other is a motorized vehicle (i.e., a motorized bike with an attached motor used to assist with pedaling). Motorized bikes are distinguished from motorcycles by being capable of being powered by pedals alone if required. The actual usage of the pedals varies widely according to the type of vehicle. Those known as mopeds mostly have pedals for emergency use; or because of legal requirements, and these pedals are not normally used. Those known as power-assist bikes have the pedals as the main form of propulsion with the motor used to give a bit of extra speed, especially uphill. The bikes used herein denote to human-powered and pedal-driven vehicles, including and not being limited to bicycles and tandem bicycles; whereas vehicles include and are unlimited to bikes, moped, tricycle and quadracycles. Bike and vehicle may be used convertably in the present invention. 
         [0007]    Power-assist vehicle is usually powered by electric motors or small internal combustion engines. With lighter batteries and better storage density, the electric motor has recently seen an increase in popularity. Currently, the electric motor can be installed nearby the front or rear wheel for powering the wheel independent of pedaling, or the motor can be installed in the vehicle frame for powering the wheel via a pedal-drivetrain (which can be a roller chain in most bikes or a driveshaft in others). When the electric motor propels the drivetrain, the pedal will rotate accordingly. If the vehicle is not properly operated under constant attention, rider may easily be injured. 
         [0008]    In order to avoid pedal rotating with drivetrain and injuring the rider, various methods have been disclosed, for example, Taiwan Patents Notice No. 1296597, M328416, etc. Although these methods could effectively reduce rider&#39;s injury, their motor-assist drivetrain cannot perform multi-gear change. Accordingly, the riders lose fun of variable-speed riding when riding such kind of power-assisted vehicle. The inventor has positively devoted his experiences and efforts to study and develop the present invention “Dual-Drivetrain of Power-Assist Vehicle”, and put the invention into manufacture. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The present invention is drawn to a dual-drivetrain for powering a vehicle by pedaling with an assistance of an attached motor. It comprises a pedal-driven part, a motor-driven part, a transmission member, and a controller. Several objects and advantage to the present invention are: (1) to provide a dual-drivetrain that can propelled a vehicle with both motor- and pedal-driven power; (2) to provide a dual-drivetrain that perform multiple-gear change, thus enhance uphill momentum; (3) to provide a dual-drivetrain that has simple structure, thus easily be manufactured and maintained. Still further objects and advantages of present invention will become apparent from a consideration of the drawings and ensuing description. 
     
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic view of the present invention applied in the vehicle&#39;s frame. 
           [0011]      FIG. 2  is an elevational view of a pedal-driven part and a motor-driven part. 
           [0012]      FIG. 3  is an isometric view of the motor-driven part. 
           [0013]      FIG. 4  is an elevational view of the motor-driven part and power conveying means. 
           [0014]      FIG. 5  is an elevation view of the dual-drivetrain of the present invention as illustrated in  FIG. 1 . 
           [0015]      FIG. 6  is a schematic diagram of the state of transmission. 
       
    
    
     REFERENCE NUMERALS IN DRAWINGS 
       [0016]      10  Pedal-driven part 
         [0017]      11  Gear plate 
         [0018]      12  Crank 
         [0019]      13  Pedal 
         [0020]      20  Motor-driven part 
         [0021]      21  Electric motor 
         [0022]      22  Drive-gear 
         [0023]      23  Relay-gear 
         [0024]      30  Gearing mechanism 
         [0025]      31  Transmission gear disc 
         [0026]      32  First transmission member 
         [0027]      33  Second transmission member 
         [0028]      50  Frame 
         [0029]      51  Rear wheel 
       DETAILED DESCRIPTION OF THE INVENTION 
     (1) The Preferred Embodiments 
       [0030]    The present invention provides a dual-drivetrain for powering a vehicle by pedaling with an assistance of an attached motor ( FIG. 1 ). It comprises a pedal-driven part  10 , a motor-driven part  20 , power conveying means, and a controller. 
         [0031]    Pedal-driven part  10 , also known as a crankset in a traditional bicycle, is pivotally mounted to a frame  50  of the vehicle ( FIG. 1 ). With reference to  FIGS. 2 &amp; 5 , it has at least one gear plate  11  (also called chainwheels or front gears), a pair of cranks  12  normally mounted  180  degree out of phase to gear plate  11 , and a pair of pedals  13  pivotally attached to each crank  12 . 
         [0032]    Motor-driven part  20  is also firmly attached to frame  50 , situated preferably between pedal-driven part  10  and a real wheel  51  ( FIGS. 1 &amp; 2 ). As illustrated in  FIG. 3 , motor-driven part  20  has an electric motor  21 , a drive-gear  22 , and a relay-gear  23 . Both drive gear  22  and relay gear  23  are pivotally attached to the armature of electric motor  21 . While drive-gear  22  can rotate either clockwise or counterclockwise, relay-gear  23  rotates only clockwise. These have been disclosed previously by Inventor (Taiwan New Model Patent Notice No. 397023) and will not be addressed in detail here. While drive-gear  22  mechanically couples real wheel  51 , relay-gear  23  couples pedal-driven part  10 . See supra. 
         [0033]    The power conveying part comprises a first transmission member  32  and a gearing mechanism  30  ( FIGS. 4 &amp; 5 ). First transmission member  32  can be as simple as a roller chain ( FIGS. 2 &amp; 3 ) that couples gear plate  11  and relay-gear  23 , resulting in a synchronized rotation of relay-gear  23  with pedal-driven part  10 . 
         [0034]    Gearing mechanism  30  is a variable-ratio transmission system for selecting appropriate gear ratios for optimum efficiency or comfort while riding a bike. It can be a derailleur mechanism or an internal hub gear mechanism. As illustrated in  FIGS. 4 &amp; 5 , the preferred gearing mechanism of the present invention is the derailleur mechanism that includes second transmission member  33 , a transmission gear disc  31 , and a rear derailleur (reference numeral not shown). Transmission gear disc  31  is a set of multiple rear-gears that has various diameters ( FIGS. 4 &amp; 5 ) and concentrically attaches to real wheel  51  ( FIG. 1 ). Second transmission member  33  can be simply a roller chain that rotationally couples one of rear-gears (i.e., transmission gear disc  31 ), the rear derailleur and relay-gear  22  (i.e., motor-driven part  20 ) ( FIGS. 4 &amp; 5 ). The rear derailleur mechanism is a well-known gearing mechanism of the art of bicycle; thereby it will not addressed here in detail. 
         [0035]    The controller (not shown in Figures) can be is mounted on the any predetermined position of frame  50  (e.g., on the down tube of the frame, on the handlebars or at the ends of triathlon bars). It includes a regulator and a shifter. See infra. 
         [0036]    The shifter is used for remotely operating gearing mechanism  30  by various well-known methods. For example, many modern bicycles utilize a cable, (e.g. a Bowden cable) for mechanically lining the shifter to the rear-derailleur (chain-guide) of the gearing mechanism. When a rider operates the lever of the shifter while pedaling, the change in cable tension moves the chain-guide from side to side, “derailing” the chain (i.e, second transmission member  23 ) onto different gears of Transmission gear disc  31 . 
         [0037]    The regulator, which electrically couples a battery (no shown in Figures) and electric motor  21 , is used for remotely regulating the rotational speed of electric motor  21 . Depending of the type of electric motor  21 , various devices are known to control motor&#39;s speed. For example, generally, the speed of a DC motor is proportional to the voltage applied to it, and the torque is proportional to the current. Speed control can be achieved by variable sbattery tappings, variable supply voltage, resistors, or electronic controls. Pulse-width modulation (PWM) is the preffered method for controlling the speed of electric motor  21 , and TL494 is the preferred electronic chip, which provides PWM power-control circuit. 
         [0038]    The regulator preferably further comprises a sensor that provides a feedback loop for adjusting rotor&#39;s speed based on vehicle&#39;s speed. It electrically couples a vehicle&#39;s speed monitor and provides feedback signal to the regulator for adjusting motor&#39;s speed based on vehicle&#39;s speed. This kind of feedback loop electronic device is well-known to one skilled in the art. 
       (2) The Best Mode of Carrying Out the Invention 
       [0039]    While pedalling, relay-gear  23  is synchronized with gear plate  11 ; the synchronization is detected by a monitor mounted in a predetermined position of frame  50 . The monitor sends signals to the sensor, which is electronically couples to the regulator that regulates electric motor  21 . Electric motor  21  rotates relay-gear  23  and produces torque output, so that raider can save labor/energy of pedalling. 
         [0040]    Not only pedalling activates electric motor  21 , but also it regulates and adjusts the speed of electric motor  21  via feedback signals from the sensor to the regulator. While the pre-determined speed of vehicle is reaching, the feedback signal stops electric motor  21  from running; relay-sprocking  23  becomes gear idling, almost without resistance. Accordingly, the armature of electric motor  21  is not rotating, is protected from wearing out, thus elongate the lifetime of electric motor  21 . While the speed is not reaching, the feedback signal protentiates electric motor  21  to run and kick in extra speed. Moreover, the controller further includes the shifter. Operating the shifter, riders can cruise all terrains by their choice of gears (i.e., speed vs. torque ration). 
         [0041]    Referring to  FIGS. 3 &amp;5 , besides pedaling, riders can directly use the controller to activate electric motor  21  for running drive-gear  22 , and use second transmission member  33  to rotate transmission gear disc  31  for driving wheel  51 . Here, gear plate  11  does not rotate by pedaling, relay-gear  23  keeps idle, and thus wheel  51  is powered by electric motor  21  (i.e., electro drive mode). In the electro drive mode, riders can also operate the shifter to “derail” to various gears and enjoy multiple gear-speed effect. 
         [0042]    Additionally, when electric motor  21  is shut down, riders will use pedals directly to lead relay-gear  23  and drive-gear  22  to operate, and then through second transmission member  33  to run transmission gear disc  31 , whereby wheel  51  is rotated with pedaling (i.e., pedal drive mode). Still, in the pedal drive mode, riders can operate the shifter to “derail” to various gears and enjoy multiple gear-speed effect. 
         [0043]    While pedaling, the sensor signals feed back to regulator; that in turn regulates electric motor  21  and rotates drive-gear  22 , whereby a huge torque output is produced. The torque enables drive-gear  22  and relay-gear  23  to produce the synchronous operation; whereby wheel  51  is powered by both pedaling and electric motor  21  (i.e., dual mixed mode). Still, in the dual mixed mode, riders can operate the shifter to “derail” to various gears, enjoy multiple gear-speed effect and enhance uphill climbing ability. 
         [0044]    It is worth mentioning that when relay-gear  23  is operated by Gear plate  11 , drive-gear  22  is running with relay-gear  23 . Only at this moment, electric motor  21  keeps the status without function (i.e., the armature of electric motor  21  dose not rotated with drive-gear  22 ), so that it can reach the effects of protecting electric motor  21 . Thus, motor-driven part  20  has been disclosed by thee original inventor (Taiwan New Model Patent Notice No. 397023 where its second wheel chain is equivalent to the drive-gear  22  of  FIG. 3 , and where its one-way rotation component is equivalent to relay-gear  23 . 
         [0045]    Finally, please refer to  FIG. 6  that is a schematic diagram of the state of transmission of this invention. The present invention approaches the electric and pedal output of duel driven effects mainly through the motion of electric motor  21  and gear plate  11 : namely, when drive-gear  22  operates, the settings of relay-gear  23  can produce gear idling, almost without resistance; the gear idling protects electric motor  21  and extends the service life of electric motor  21 . Because transmission gear disc  31  is formed by a plurality of rear-gears of various diameters, regardless pedal-driven or electric-driven, riders can operate on the shifter of the controller for controlling gearing mechanism  30  so that second transmission member  33  will couple drive-gear  22  to one of the rear-gears accordingly, whereby suitable speed-torque ratio can be achieved. The riders can enjoy multiple gearing (speed-to-torque ratio) while riding in various kinds of terrains and exercising by their own choice (pedal-, electronic-, or mixed-mode). 
         [0046]    Moreover, pedal-driven part  10  may include a plurality of gear plate  11  of various diameters. This design is known and used in the modern bicycles, so that it will not describe here further. However, it is worth to mention here that the functional wheel transmission gear disk  11  is formed by the designed gear plate  11  of plural concentric outer diameters, to form a set of various stall transformation with relay-gear  23 , to enable the rider to proceed the stall transformation of gear plate  11 , further to correspond to the stall transformation of transmission gear disc  31 , in order to reach the effects of multi-stage speed change; Also, the controller (not shown in figure) can be the output signal, to be the speed adjustment of electric motor  21 , to achieve the effects of variable-speed change and stop. The preferred embodiments and the best mode of carrying out the invention are intended to illustrate but not to limit the present invention. It will be apparent to one skilled in the art that various substitutions and modifications may be made to the invention disclosed herein without departing form the scope and the spirit of the invention. Accordingly, these substitutions, and modifications, and their legal equivalents are intended to be within the scope of present invention.