Patent Publication Number: US-RE45441-E

Title: Hand crank generator

Description:
BACKGROUND OF THE INVENTION 
     This application claims priority from Taiwanese patent application 96201562 U, filed Jan. 26, 2007. 
     (a) Field of the Invention 
     The present invention is related to a hand crank generator, and more particularly, to one that is applied in small sized electric appliances. 
     (b) Description of the Prior Art 
     Small size electric appliances, e.g., flashlights, battery chargers, are indispensable in our daily life; however, so far all these small sized electric appliances must use batteries or connection to a power source to operate. Though those battery dependent products permit easy portability and convenient use, battery must be continuously replaced or recharged due to the limited storage capacity of the battery. As a result, these electric appliances are not necessarily always readily available; and that could be a problem particularly for those who spend much time on the road. To correct this problem, a hand crank generator is introduced into the market. 
     Conventional hand crank generator operates generators operate by cranking to drive gears to rotate, and those gears in turn directly drives drive the generator. Once the cranking stops, the generator also stops generating power. Accordingly, to generate more power, a great effort must be consumed to in exchange for sufficient electric energy. 
     SUMMARY OF THE INVENTION 
     The primary purpose of the present invention is to provide a hand crank generator that is simple in construction and allows easy operation. 
     To achieve the purpose, a hand crank generator is essentially comprised of a crank, a gear transmission, and a generation motor generator driven by the gear transmission; the crank and the gear transmission are coupled to each other, and the gear transmission and the generation motor generator are coupled to each other with a clutch gear. 
     The crank is provided with an arm and a handle; and the handle is disposed to a terminal of the arm. 
     The clutch gear is connected to a deflection shaft, which in turn is connected to a second shaft disposed in the gear transmission through a connection plate;, and both ends of the deflection shaft are located in a deflection groove. 
     A motor generator gear is fixed to a central shaft of the generation motor generator and the motor generator gear engages with the clutch gear. 
     A weighted wheel is further fixed to a terminal of the central shaft of the generation motor generator. With the inherited inertia provided by the weighted wheel, the generation motor generator is capable of continuous revolution for a while when the external force applied on the crank disappears. 
     The gear transmission includes a first transmission gear, a second double gear, a third double gear, and a fourth double gear; wherein the first transmission gear is fixed to the arm, and the first gear engages with a pinion in the second double gear; a gearwheel of the second double gear engages with a pinion in the third double gear; a gearwheel of the third double gear engages with a pinion in the fourth double gear; and the gearwheel of the fourth double gear engage with the clutch gear. The gear transmission adopts a three-stage acceleration design to increase output revolution speed. 
     Alternatively, the gear transmission may be comprised of a first revolving gear and a second double gear; wherein the first revolving gear is connected to a shaft and the second double gear is connected to a second shaft; the first revolving gear is fixed to the crank; the first revolving gear engages with a pinion in the second double gear; and a gearwheel of the second double gear engages with the clutch gear. 
     In the present invention, the crank is driven manually to further drive the gear transmission and then the generation motor generator revolves as driven by the clutch gear to generate electric current. When the manual cranking stops, the clutch gear is disengaged from the motor generator gear on the generation motor generator; however, given with the inertia provided by the weight wheel, the motor generator gear continues to revolve for a while to drive the generation motor generator to keep generating electric current. Accordingly, a user may save lots of efforts effort. Furthermore, the present invention may be connected to an energy accumulator like a battery to become provide another product with for a different application when the present invention is electrically connected to an electricity input end of a light emitting object or other electric electrical appliance through the an energy accumulator like a battery. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a preferred embodiment of the present invention. 
         FIG. 2  is a schematic view showing an internal construction of the preferred embodiment of the present invention. 
         FIG. 3  is a schematic view showing a clutch gear and a motor generator gear in the preferred embodiment of the present invention. 
         FIG. 4  is a schematic view showing a status wherein the clutch gear and the motor generator gear are disengaged from each other in the preferred embodiment of the present invention. 
         FIG. 5  is a schematic view showing a deflection groove provided to the clutch gear in the preferred embodiment of the present invention. 
         FIG. 6  is a schematic view showing another preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 and 2  for a preferred embodiment of the present invention, a hand crank generator of the present invention is comprised of a crank  1 , a gear transmission  2 , a generation motor generator  3 , a clutch gear  4 , and a weighted wheel  5 . Wherein, the gear transmission  2  is mounted in a box  6 ; the crank  1  is connected to an input end of the gear transmission  2  to drive the gear transmission  2 ; the clutch gear  4  is located at an output end of the gear transmission  2  and engages with a motor generator gear  32  disposed on a central shaft  31  of the generation motor generator  3  to drive the generator for generating electric current; and the crank  1  is provided with an arm  11  and a handle  13  with the handle mounted to one end of the arm  11 . 
     The gear transmission  2  of the preferred embodiment is essentially comprised of a first transmission gear  21 , a second double gear  22 , a third double gear  23 , and a fourth double gear  24 . Wherein, the first transmission gear  21  and the third double gear  23  are connected to a shaft  12 ; the second double gear  22  and the fourth double gear  24  are connected to a second shaft  25 ; and both of the shaft  12  and the second shaft  25  are secured in place by multiple locating holes disposed on the box  6 . The first transmission gear  21  is fixed to the crank  1  for the crank  1  to directly drive the first transmission gear  21  to revolve; the first transmission gear  21  engages with a pinion in the second double gear  22 ; a gearwheel of the second double gear  22  engages with a pinion in the third double gear  23 ; a gearwheel of the third double gear  23  engages with a pinion in the fourth double gear  24 . The input revolution speed from the crank  1  is increased through the series transmission executed by the gear transmission  2 . Finally, a gearwheel of the fourth double gear  24  engages with the clutch gear  4  to further increase the revolution speed. Accordingly, the generation motor generator  3  is driven to produce higher revolution speed for upgrading generation efficiency. 
     The installation of the clutch gear  4  constitutes the most important feature of the present invention. When an external force is applied to drive the crank  1  to further drive the gear transmission  2  to operate, the clutch gear engages with a motor generator gear  32  disposed on the generation motor generator  3  to drive the generator to generate power; when the external force applied on the crank  1  disappears, the clutch gear  4  disengages from the motor generator gear  32 , but the central shaft where the generation motor generator is located continues to revolve for power generation for a while due to the inertia from the weighted wheel even when the crank  1  stops. Therefore the generation motor generator  3  continues to operate for a while when the crank  1  stops operating. 
     Now referring to  FIGS. 3 ,  4 , and  5 , the clutch gear  4  connected to a deflection shaft  41 , which is connected to the second shaft  25  in the gear transmission  2  through a connection plate while the clutch gear  4  engages with the gearwheel of the fourth double gear  24 . Furthermore, the connection plate  42  holds the clutch gear  4  firmly in position to prevent its axial angle from deflection. To limit the deflection angle of the clutch gear  4 , both ends of the deflection shaft  41  are disposed in a deflection groove  61  in the present invention. When the crank  1  drives the gear transmission, the fourth double gear  24  rotates clockwise for its gearwheel to drive the clutch gear to revolve. Since the clutch gear  4  is situated in a non-fixation status, the fourth double gear  24  will drive the clutch gear to deflect clockwise for the clutch gear  4  to engage with the motor generator gear  32  on the generation motor generator  3  to drive the generation motor generator  3  to revolve. When an external force applied on the crank  1  disappears, the fourth double gear  24  stops rotating and a force acting upward as produced by the fourth double gear  24  upon the clutch gear  4  also disappears; but the motor generator gear  32  under action of inertia continues to rotate clockwise for a while. As the motor gear  32  continues to rotate, the clutch gear  4  is pushed to downward deflect to cause the clutch gear  4  to disengage from the motor generator gear  32 . As a result, the motor generator gear  32  idles to drive the central shaft  31  to continue rotation for a given time before the central shaft  31  stops rotating. Before the central shaft  31  stops rotating, the generation motor generator  3  keeps operating. 
     A weighted wheel  5  is fixed to a terminal of the central shaft  31  of the generation motor generator  3  to increase inertia rotation for the generation motor generator  3 . The weight wheel  5  rotates at the same time when the crank  1  drives the generation motor generator  3  to operate. Whereas the weight wheel  5  is given with a relatively greater mass, it produces greater inertia. Therefore, once the central shaft  31  idles, it continues to rotate for a longer time as driven by the weighted wheel  5  to provide better generation capability a more efficient system. 
     In another preferred embodiment of the present invention as illustrated in  FIG. 6 , a gear transmission  2  is comprised of a first transmission gear  21  and a second double gear  22 . Wherein, the first transmission gear  21  connected to a shaft  12 ; the second double gear  22  connected to a second shaft  25 ; the first transmission gear is fixed to a crank  1 ; and the first transmission gear  21  engages with a pinion in the second double gear  22 . The gear transmission in the preferred embodiment delivers only a regular acceleration. Furthermore, a weighted wheel  5  is disposed beneath a generation motor generator  3  in the preferred embodiment. 
     The quantity of gears to be provided in the present invention is not restricted and the quantity may be added or reduced as applicable. Furthermore, the connection plate  42  may be installed or removed depending on the construction of the gear transmission that is adapted to.