Mechanism for controlling circuit-closing/opening of power ratchet wrench

A mechanism for controlling circuit-closing/opening of power ratchet wrench, including: an elongated tubular main body for a user's hand to hold; a driving motor disposed in the main body; a transmission member disposed in the main body and connected with the driving motor for transmitting the power of the driving motor; a driving end disposed at the first end of the main body and drivable by the driving motor via the transmission member; a power supply for supplying power to the driving motor; a driving power supplying circuit disposed in the main body and electrically connected between the power supply and the driving motor, whereby the power supply can power on the driving motor via the driving power supplying circuit a controlling trigger, one end of the controlling trigger being pivotally connected with the main body. The controlling trigger is such arranged that when a user's hand encloses and holds the main body, the user's hand also encloses and holds the controlling trigger to control the closing/opening of the driving power supplying circuit.

BACKGROUND OF THE INVENTION

The present invention is related to a power ratchet wrench, and more particularly to a mechanism for controlling circuit-closing/opening of a power ratchet wrench.

A conventional power ratchet wrench has an elongated tubular main body in which various components of the power ratchet wrench are accommodated. Referring toFIG. 1, a user's hand can hold the main body to operate the power ratchet wrench1. In operation, the user's thumb must always press the circuit-closing/opening press key2for closing the circuit to power on the driving unit inside the main body. When releasing the press key, the power is cut off.

In actual operation, the power ratchet wrench is often operated at high torque and high rotational speed. Under such circumstances, it is inconvenient for a user to hold the power ratchet wrench due to improper design of the circuit-closing/opening press key.

In order to stably operate the power ratchet wrench, a user's hand must tightly enclose and hold the main body of the power ratchet wrench. However, the user's thumb always needs to press the circuit-closing/opening press key. Therefore, the user's hand can hardly fully enclose the main body of the power ratchet wrench. Accordingly, the user's hand can hardly firmly hold the power ratchet wrench. Consequently, it often takes place that the power ratchet wrench jumps out of the user's hand due to shock in operation.

U.S. Pat. Nos. 6,923,095 and 5,195,406 disclose a control valve structure for closing/opening airflow passage of pneumatic ratchet wrench. Such control valve structure enables a user to more firmly hold the pneumatic ratchet wrench in operation. However, no similar measures applicable to power ratchet wrench have been disclosed.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide a mechanism for controlling circuit-closing/opening of a power ratchet wrench. When controlling the circuit-closing/opening of the power ratchet wrench, a user's hand can still fully enclose and stably hold the main body of the power ratchet wrench. Therefore, the power ratchet wrench will not jump out of the user's hand due to shock in operation so as to ensure safety.

It is a further object of the present invention to provide the above mechanism for controlling circuit-closing/opening of the power ratchet wrench, in which one single controlling trigger is used to control multiple circuit closing/opening controlling switches.

According to the above objects, the mechanism for controlling circuit-closing/opening of the power ratchet wrench includes: an elongated tubular main body for a user's hand to hold; a driving motor disposed in the main body; a transmission member disposed in the main body and connected with the driving motor for transmitting the power of the driving motor; a driving end disposed at the first end of the main body and drivable by the driving motor via the transmission member; a power supply for supplying power to the driving motor; a driving power supplying circuit disposed in the main body and electrically connected between the power supply and the driving motor, whereby the power supply can power on the driving motor via the driving power supplying circuit a controlling trigger, one end of the controlling trigger being pivotally connected with the main body. The controlling trigger is such arranged that when a user's hand encloses and holds the main body, the user's hand also encloses and holds the controlling trigger to control the closing/opening of the driving power supplying circuit.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer toFIGS. 2 to 6. The mechanism10for controlling circuit-closing/opening of power ratchet wrench of the present invention includes a main body11, a driving motor12, a transmission member13, a driving end14, a power supply15, an illuminating light16, a driving power supplying circuit, an illuminating power supplying circuit, a driving circuit closing/opening controlling switch17, an illuminating circuit closing/opening controlling switch18and a controlling trigger19.

The main body11is an elongated tubular body composed of two halves111,112mated with each other. The main body11has an internal space in which other components of the power ratchet wrench are accommodated. The main body has a configuration adapted to a human hand, whereby a user's hand can enclose and hold the main body.

The driving motor12is coaxially received in the internal space of the main body11. The driving motor12has an output shaft parallel to the axis of the main body11and directed to a first end of the main body11.

The transmission member13is shafted on the output shaft of the driving motor12and accommodated in the internal space of the main body11.

The driving end14is disposed at the first end of the main body11and coupled with the transmission member13. The transmission member13serves to transmit the power of the driving motor12to the driving end14for wrenching a work piece.

The power supply15is a power storage unit such as a cell package inserted in a second end of the main body11and extending into the internal space of the main body11.

The illuminating light16can be a light-emitting diode fixedly disposed at the first end of the main body11and adjacent to the driving end14. The illuminating light16serves to illuminate an operating area of the driving end14.

The driving power supplying circuit and the illuminating power supplying circuit are respectively electrically connected between the power supply15and the driving motor12and the illuminating light16. Accordingly, the power supply15can power on the driving motor12and the illuminating light16via the driving power supplying circuit and the illuminating power supplying circuit. The driving power supplying circuit and the illuminating power supplying circuit are combined into a circuit board20disposed in the main body11.

The driving circuit closing/opening controlling switch17is fixedly disposed on the circuit20and electrically connected with the driving power supplying circuit. The driving circuit closing/opening controlling switch17has a touch-controlled key171. When an external physical force is applied to the touch-controlled key171, the touch-controlled key171mechanically controls the closing/opening of the driving power supplying circuit.

The illuminating circuit closing/opening controlling switch18is fixedly disposed on the circuit20and adjacent to the driving circuit closing/opening controlling switch17. The illuminating circuit closing/opening controlling switch18has a press key181and a leaf spring182attaching to the press key181. The press key181is operable in a direction parallel to the axis of the main body11. Accordingly, the leaf spring182can exert a physical force onto the press key181to mechanically control the closing/opening of the illuminating power supplying circuit.

The controlling trigger19has an elongated body section191which is mounted on one side of the main body11in parallel to the axis thereof. One end of the body section191is formed with a pivot section192inlaid in a pair of pivot holes113of the two halves111,112to pivotally connect the body section191with the main body11. Accordingly, the body section191can be pivoted about the pivot section192between a releasing position and a pressing position. A spring193resiliently keeps the body section191in the releasing position. A first touch-controlled projection194is formed on the body section191and spaced from the pivot section192by a longer distance. The first touch-controlled projection194extends from the body section191by a shorter length. A free end of the first touch-controlled projection194can pass through a through hole114of the main body11to face the touch-controlled key171. A second touch-controlled projection195is formed on the body section191and spaced from the pivot section192by a shorter distance. The second touch-controlled projection195extends from the body section191by a longer length. A free end of the second touch-controlled projection195can pass through a through hole115of the main body11to be adjacent to the leaf spring182.

According to the above arrangement, in operation, when a user's hand encloses and holds the main body11of the power ratchet wrench, all the fingers of the user's hand except the thumb can pull or loosen the controlling trigger19to control the position of the controlling trigger19. Accordingly, it is no more necessary to move the thumb for pressing or releasing the press key as in the conventional technique. Therefore, the user's hand can always enclose the main body11to more reliably hold the same in operation.

Moreover, in the above structure, one single controlling trigger19is used to simultaneously control both the driving circuit closing/opening controlling switch17and the illuminating circuit closing/opening controlling switch18. When the user's hand encloses and holds the main body11tight, the controlling trigger19is pivotally biased from the releasing position to the pressing position. When the controlling trigger19reaches a position between the releasing position and the pressing position, the free end of the second touch-controlled projection195first presses the leaf spring182to switch on the illuminating circuit closing/opening controlling switch18. Therefore, before the driving motor12is powered on, the illuminating light16first illuminates the operation area of the driving end14. Then, when the user's hand further holds the main body11tight, the controlling trigger19is positioned in the pressing position where the free end of the first touch-controlled projection194presses the touch-controlled key171to switch on the driving circuit closing/opening controlling switch17for powering on the driving motor12and wrenching a work piece. This facilitates operation of the power ratchet wrench and ensures safety in use of the power ratchet wrench.