Abstract:
An impact enhancing device of an electric nailer, comprising: an AC power source, a protection circuit, a first switch, a full-wave rectifier, a timing controller circuit, an energy-storage circuit, a solid-state switch circuit, an electromagnetic coil device, a DC power source, a second switch, a reset enable single shot trigger circuit, and a relay. Thus, the electric nailer provides a larger impact force with a smaller volume and a lighter weight.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to an impact enhancing device of an electric nailer, and more particularly to an impact enhancing device of an electric nailer, wherein the electric nailer provides a larger impact force with a smaller volume and a lighter weight.  
         SUMMARY OF THE INVENTION  
         [0002]    The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional electric nailer.  
           [0003]    The primary objective of the present invention is to provide an electric nailer containing an impact enhancing device, wherein the electric power stored in the energy-storage capacitor of the energy-storage circuit discharges to the electromagnetic coil of the electromagnetic coil device in a short period of time, thereby obtaining the maximum and optimum impact force.  
           [0004]    In accordance with one aspect of the present invention, there is provided an electric nailer having an impact enhancing device, comprising: an alternating current power source, a protection circuit, a first switch, a full-wave/multiplying rectifier, a timing controller circuit, an energy-storage circuit, a solid-state switch circuit, an electromagnetic coil device, a direct current power source, a second switch, a reset enabling single shot trigger circuit, and a relay.  
           [0005]    Preferably, the full-wave doubler includes two diodes and two electrolytic capacitors, so as to obtain a direct current voltage that is two times of an alternating current voltage.  
           [0006]    Preferably, the full-wave tripler includes three diodes and three electrolytic capacitors, so as to obtain a direct current voltage that is three times of an alternating current voltage.  
           [0007]    Preferably, the timing controller circuit contains a timing controller resistor connected to an output terminal of the full-wave rectifier in a coupling manner.  
           [0008]    Preferably, the energy-storage circuit contains an energy-storage capacitor connected to one side of a normally closed connector of the relay in a coupling manner and connected to one port of an electromagnetic coil of the electromagnetic coil device in a coupling manner.  
           [0009]    Preferably, the electromagnetic coil device includes an electromagnetic coil and an impact stroke device, the electromagnetic coil of the electromagnetic coil device contains a first port connected to the anode of a silicon controller rectifier (SCR) of the solid-state switch circuit and a second port connected to the positive terminal of an energy-storage capacitor of the energy-storage circuit and to one side of a normally closed connector of the relay, the energy-storage capacitor of the energy-storage circuit contains a negative terminal connected to the cathode of the SCR of the solid-state switch circuit, wherein:  
           [0010]    when the SCR of the solid-state switch circuit is conducted, the electromagnetic coil generates an electromagnetic force, so that the impact device generates an impact force because of magnetism.  
           [0011]    Preferably, the solid-state switch circuit includes a SCR and two voltage divider resistors, the SCR contains an anode connected to one port of an electromagnetic coil of the electromagnetic coil device and a cathode connected to the negative terminal of an energy-storage capacitor of the energy-storage circuit, each of the two voltage divider resistors contains a first port connected to a normally opened connector of the relay and a second port connected to the gate of the SCR, wherein:  
           [0012]    when the two voltage divider resistors are subjected to a voltage, the SCR is conducted, so that the energy-storage capacitor of the energy-storage circuit discharges a current to pass through the electromagnetic coil of the electromagnetic coil device, thereby producing an electromagnetic force.  
           [0013]    Preferably, the SCR can be replaced by a Triac thyristor, MOSFET, IGBT, or other solid-state switch device.  
           [0014]    Preferably, the relay includes an electromagnetic coil, a normally closed connector and a normally opened connector, the electromagnetic coil contains a first port connected to the collector of a transistor of the reset enable single shot trigger circuit and a second port connected to the positive terminal of the direct current (DC) power source, the normally closed connector contains a first port connected to the positive terminal of an energy-storage capacitor of the energy-storage circuit and to one port of an electromagnetic coil of the electromagnetic coil device and a second port connected to the positive terminal of the full-wave rectifier is a full-wave tripler, and the normally opened connector contains a first port connected to the first port of the normally closed connector, to the positive terminal of the energy-storage capacitor of the energy-storage circuit and to the one port of the electromagnetic coil of the electromagnetic coil device and a second port connected to one port of a voltage divider resistor of the solid-state switch circuit, wherein:  
           [0015]    the relay circuit conducts the energy-storage capacitor of the energy-storage circuit and supplies an electric power to the voltage divider resistor of the solid-state switch circuit.  
           [0016]    Preferably, the reset enable single shot trigger circuit includes two state changing resistors, a timing controller capacitor, a timing controller resistor, two voltage divider resistors, a transistor, and a timing controller module circuit, wherein:  
           [0017]    the timing controller module circuit outputs an impulse to the base of the transistor so that the electromagnetic coil of the relay operates.  
           [0018]    Preferably, the direct current power source includes a voltage drop resistor, a zener diode and a filtering capacitor, the voltage drop resistor contains one port connected to an output positive terminal of the full-wave rectifier, wherein:  
           [0019]    the DC power source supplies a DC voltage to the reset enable single shot trigger circuit and the electromagnetic coil of the relay.  
           [0020]    In accordance with another aspect of the present invention, there is provided a circuit device for inverting a DC power source into an alternating current (AC) power source, comprising:  
           [0021]    a photo coupler module circuit including a light emitting diode containing a first port connected to a first port of a current limited resistor and a second port connected to the grounding port of the reset enable single shot trigger circuit, the current limited resistor contains a second port connected to an impulse output terminal of a timing controller module circuit, wherein the photo coupler module circuit transfers an impulse signal; and  
           [0022]    a relay circuit including an electromagnetic coil, a normally closed connector, a normally opened connector, a transistor, and a base resistor, wherein the electromagnetic coil contains a first port connected to the positive terminal of a DC power supply and a second port connected to the collector of the transistor, the emitter of the transistor is grounding, the base of the transistor is connected to the base resistor and to a first port of the output port of the photo coupler module circuit, the output port of the photo coupler module circuit contains a second port connected to the first port of the current limited resistor, the normally closed connector contains a first port connected to a first port of a first switch of the DC power supply and a second port connected to the positive supply terminal of an oscillation circuit, the first switch of the DC power supply contains a second port connected to the positive terminal of the DC power supply, so that when the output port of the photo coupler module circuit is conducted, the oscillation circuit stops operation, and when the output port of the photo coupler module circuit is shutoff, the oscillation circuit starts operating.  
           [0023]    Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]    [0024]FIG. 1 is a block view of an impact enhancing device of an electric nailer in accordance with a first embodiment of the present invention;  
         [0025]    [0025]FIG. 2 is a circuit diagram of the impact enhancing device of the electric nailer in accordance with the first embodiment of the present invention;  
         [0026]    [0026]FIG. 3 is a circuit diagram of the impact enhancing device of the electric nailer in accordance with the second embodiment of the present invention;  
         [0027]    [0027]FIG. 4 is a circuit diagram of the impact enhancing device of the electric nailer in accordance with the third embodiment of the present invention; and  
         [0028]    [0028]FIG. 5 is a circuit diagram of the impact enhancing device of the electric nailer in accordance with the fourth embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0029]    Referring to the drawings and initially to FIGS. 1 and 2, an impact enhancing device of an electric nailer in accordance with a first embodiment of the present invention comprises an alternating current power source  10 , a protection circuit  20 , a first switch  30 , a full-wave doubler/full-wave rectifier  40 , a timing controller circuit  50 , an energy-storage circuit  60 , a solid-state switch circuit  70 , an electromagnetic coil device  80 , a DC power source  90 , a second switch  100 , a reset enable single shot trigger circuit  200 , and a relay  300 .  
         [0030]    When the first switch  30  is disposed at the “ON” state, the alternating current passes through the protection circuit  20  and the first switch  30  to the full-wave doubler  40 . The full-wave doubler  40  includes two diodes  41  and  42  and two electrolytic capacitors  43  and  44 . The negative terminal of the electrolytic capacitor  43  is connected to the positive terminal of the electrolytic capacitor  44  at a first terminal of the AC power source  10 . The P junction of the diode  41  is connected to the N junction of the diode  42  at a second terminal of the alternating current power source  10 . The N junction of the diode  41  is connected to the positive terminal of the electrolytic capacitor  43  to form the positive output terminal of the full-wave doubler  40 . The P junction of the diode  42  is connected to the negative terminal of the electrolytic capacitor  44  to form the negative output terminal of the full-wave doubler  40 .  
         [0031]    The current from the positive output terminal of the full-wave doubler  40  passes through the timing controller resistor  51  of the timing controller circuit  50 , the normally closed connector  302  of the relay  300  and flows into the energy-storage capacitor  61  of the energy-storage circuit  60  to perform a charging process. At this time, the DC from the positive terminal of the electrolytic capacitor  44  flows into the voltage drop resistor  91  of the DC power source  90  and passes through the N junction of the zener diode  92  and the positive terminal of the filtering capacitor  93  of the DC power source  90 .  
         [0032]    At this time, the N junction of the zener diode  92  supplies a DC voltage to the reset enable single shot trigger circuit  200 . The reset enable single shot trigger circuit  200  includes a second switch  100 , two state changing resistors  201  and  202 , a timing controller capacitor  204  for outputting the pulse, a timing controller resistor  203 , a pulse output circuit containing two voltage divider resistors  205  and  206 , a transistor  207 , and a timing controller module circuit  208 . When the second switch  100  is disposed at the “ON” state, a pulse voltage exists in the pulse output circuit. The period of the pulse voltage is T=KRC, wherein K is a constant depending on the timing controller module circuit, R is the value of the timing controller resistor, and C is the value of the timing controller capacitor.  
         [0033]    At this time, the transistor  207  is disposed at the “ON” state. Thus, the electromagnetic coil  301  is energized, so that the normally opened connector  303  of the relay  300  is disposed at the “ON” state. At this time, the gate of the silicon controller rectifier (SCR)  71  of the solid-state switch circuit  70  is subjected to the mid-point voltage of the two voltage divider resistors  72  and  73  of the solid-state switch circuit  70  to turn into the “ON” state. At this time, the energy-storage capacitor  61  of the energy-storage circuit  60  discharges toward the electromagnetic coil  81  of the electro-magnetic coil device  80 .  
         [0034]    Thus, the electric power of the electromagnetic coil  81  of the electromagnetic coil device  80  is P=CV 2 /t, wherein C is the value (the unit of C is Farad, F) of the energy-storage capacitor  61  of the energy-storage circuit  60 , V is the voltage of the DC (the unit of V is Volt), and t is the time (the unit of t is second). Thus, the required electromagnetic force is obtained by using a proper energy-storage capacitor  61  of the energy-storage circuit  60 . When the electromagnetic coil  81  of the electromagnetic coil device  80  is energized, the impact stroke device  82  of the electromagnetic coil device  80  is operated. The impact stroke device  82  of the electromagnetic coil device  80  is magnetized by the electromagnetic coil device  80  and moving toward the electromagnetic coil device  80  in high speed, so as to eject the nail outward.  
         [0035]    Referring to FIG. 3, in accordance with a second embodiment of the present invention, the full-wave tripler  40  includes three diodes  41 ,  42  and  45  and three electrolytic capacitors  43 ,  44  and  46 . Thus, the voltage of the two ports of the electrolytic capacitor  46  is three times of the DC voltage of the AC power source, and is supplied into the energy-storage capacitor  61  of the energy-storage circuit  60  to perform a charging process. According to the formula of P=CV 2 /t, when the voltage V of the two ports of the energy-storage capacitor  61  of the energy-storage circuit  60  is increased, the capacitance C is increased, so that the electric power P of the electromagnetic coil  81  of the electromagnetic coil device  80  is increased, the magnetized energy is increased as well.  
         [0036]    Referring to FIG. 4, in accordance with a third embodiment of the present invention, when the AC power source  10  has different values, such as AC-110V or AC-220V, the impact enhancing device of the electric nailer in accordance with the present invention further comprises a switch  49 . Thus, when the switch  49  is directed toward the junction “A”, the AC power source  10  supplies a voltage of 220V. Alternatively, when the switch  49  is directed toward the junction “B”, the AC power source  10  supplies a voltage of 110V. In addition, the output impulse of the reset enable single shot trigger circuit  200  is supplied to the gate the MOSFETS  74  of the solid-state switch circuit  70 . That is, the SCR  71  of the solid-state switch circuit  70  can be replaced by the MOSFETS  74 , the IGBT, or other solid-state switch device, and the relay  300  is omitted. Thus, the electric power P of the electromagnetic coil  81  of the electromagnetic coil device  80  is controlled by the period of the output impulse.  
         [0037]    Referring to FIG. 5, in accordance with a fourth embodiment of the present invention, the voltage of the DC power supply  500  is inverted through an inverter circuit  400  into a high frequency AC voltage which flows into the secondary  408  of the high frequency transformer  407 , and is then rectified by the full-wave rectifier  40 , and the electric power is stored at the two ports of the energy-storage capacitor  61  of the energy-storage circuit  60  to perform a charging process. At this time, if the second switch  100  is disposed at the “ON” state, the reset enable single shot trigger circuit  200  outputs an impulse which passes through the gate of the SCR  71  of the solid-state switch circuit  70 , the current limited resistor  209 , and flows into the light emitting diode  212  of the photo coupler module circuit  211 . At this time, the output side  213  of the photo coupler module circuit  211  is conducted, and the two ports of the base resistor  402  of the transistor  403  is subjected to the voltage, so that the transistor  403  is conducted, and the electromagnetic coil  405  of the relay  404  is energized, so that the normally closed connector  406  of the relay  404  is disposed at the “OFF” state. At the same time, the SCR  71  of the solid-state switch circuit  70  is turned into the “ON” state. Thus, the electromagnetic coil  81  of the electromagnetic coil device  80  is energized to generate the electro-magnetic power, so that the impact device  82  of the electromagnetic coil device  80  is operated, so as to eject the nail outward. At this time, the light emitting diode  212  of the photo coupler module circuit  211  does not emit light, so that the electro-magnetic force of the electromagnetic coil  405  of the relay  404  disappears, and the normally closed connector  406  of the relay  404  is disposed at the “ON” (or closed) state.  
         [0038]    While the preferred embodiment(s) of the present invention has been shown and described, it will be apparent to those skilled in the art that various modifications may be made in the embodiment(s) without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention.