Abstract: A flow-bypassing structure and a grinding tool having the same are provided. A main body of the grinding tool has an intake passage and an exhaust passage. A cylinder is disposed in an interior of the main body and has an air inlet communicated with the intake passage and an air outlet communicated with the exhaust passage to form an airflow pathway. A rotor is disposed in the cylinder, and a rotational axle base is rotatably disposed though the cylinder and in a rotational cooperative relationship with the rotor. An end of the rotational axle base is extended and formed with a rotational working portion outside the cylinder. The surroundings of the rotational working portion define a space. A flow-bypassing passage is communicated with the airflow pathway and the space, and an end of the flow-bypassing passage is open toward the space.

Abstract: The present invention relates to a flow-bypassing structure and a grinding tool having the same. The main body has an intake passage and an exhaust passage. A cylinder is disposed in an interior of the main body and has an air inlet communicated with the intake passage and an air outlet communicated with the exhaust passage to form an airflow pathway. A rotor is disposed in the cylinder, and a rotational axle base is rotatably disposed though the cylinder and in a rotational cooperative relationship with the rotor. An end of the rotational axle base is extended and formed with a rotational working portion outside the cylinder. The surroundings of the rotational working portion define a space. A flow-bypassing passage is communicated with the airflow pathway and the space, and an end of the flow-bypassing passage is open toward the space.

Abstract: A double-valve mechanism and a pneumatic tool including the same are provided. The double-valve mechanism is mounted in a main body of the pneumatic tool. The main body has an exhausting passage and an outlet passage communicating therewith, and an entrance passage and an inlet passage communicating therewith. The double-valve mechanism is operable from outside of the main body to move relative to the main body so as to selectively seal an entry of the inlet passage and an exit of the outlet passage. Whereby, the stop of the tool is effectively ensured after the double-valve mechanism is closed, no gas leakage will occurs, the waste of pressurized air energy and defects of the tool will be avoided, and the rotation of the rotor can be quickly stopped.

Abstract: A rotatable lever structure of a pneumatic tool and a pneumatic tool including the same are provided. The rotatable lever structure is mounted to a main body of the pneumatic tool. The main body has a first portion and a second portion. The first portion is arranged with a lever and an entrance passage for pressurized air. A connection mechanism is detachably mounted to the second portion, and the first portion and the second portion are relatively rotatably connected via the connection mechanism. Whereby, the lever can be selectively rotated relative to the second portion, and is easy to use and less limited for various working environments.

Abstract: An impact body adapted for being mounted to a transmission module is provided. The transmission module includes a rotation portion formed with a receiving space and an axle disposed in the receiving space. The impact body is pivotally mounted to the rotation portion and received in the receiving space. A protrusion integrally extends outwardly from the other side of the impact body to allow the impact body swings around the protrusion. Whereby, the transmission module is easy to produce and assemble, has a lighter weight or greater rotary output power, and can improve transmission efficiency and lifetime, thus resulting in great inventive effects for use.

Abstract: A power driven ratchet wrench includes a handle, a working portion and a switch portion. The working portion includes a yoke, a ratchet head and a socket. The yoke is disposed on the handle and defines a receiving space therein, and it has a first through hole. The ratchet head is coupled with a transmission element and has a third through hole corresponding to the first through hole. The ratchet head is swayable about an axis of the socket. The switch portion includes a switching button and an engaging unit. The engaging unit stops the socket from relatively rotating in a first direction as the switching button locates at a first switch position. The engaging unit stops the socket from relatively rotating in a second direction as the switching button locates at a second switch position.

Abstract: A pneumatic motor of the present invention is provided for pneumatic tool. The pneumatic motor includes a cylinder, a rotor and a controlling valve. The rotor is rotatably disposed in the cylinder. Two gas passages and an exhaust hole are defined by the cylinder. The exhaust hole extends along a circular direction of the rotor. The exhaust hole has a first end and a second end. The exhaust hole is partially covered by the controlling valve. The exhaust hole has a remained opened portion which is adapted for air to flow therethrough. The controlling valve is adjustable so as to change position of the opened portion. As such, a power stroke in the cylinder is able to be adjusted, so that the power generated by the pneumatic motor is changeable.

Abstract: A transmission module includes a sleeve member, a cover disc, a hammering portion and an axle. The sleeve member has a rear disc and a cylinder body. A receiving space is defined between the rear disc and the cylinder body. The rear disc is formed with a teethed bore. The inner surface of the cylinder body is formed with at least one axially-stretched rib. The cover disc is disposed on the open end of the receiving space. The cover disc is formed with an axial bore. The hammering portion includes at least one rotary hammer, which is received in the receiving space. The rotary hammer has a through hole and a positioning groove. The rib is engaged with the positioning groove. The axle has a driven end and a working end. The driven end is inserted through the axial bore and mated with the through hole.

Abstract: A power driven ratchet wrench includes a handle, a working portion and a switch portion. The working portion includes a yoke, a ratchet head and a socket. The yoke is disposed on the handle and defines a receiving space therein, and it has a first through hole. The ratchet head is coupled with a transmission element and has a third through hole corresponding to the first through hole. The ratchet head is swayable about an axis of the socket. The switch portion includes a switching button and an engaging unit. The engaging unit stops the socket from relatively rotating in a first direction as the switching button locates at a first switch position. The engaging unit stops the socket from relatively rotating in a second direction as the switching button locates at a second switch position.

Abstract: A pneumatic tool includes a shell with a chamber defined therein, a first passage communicated with the chamber and a second passage communicated with the chamber. A rotor is installed in the chamber for rotation when driven by pressurized air flowing into the chamber through the first passage. A shaft extends to the exterior of the shell from the rotor. A trigger is installed on the shell. A control device is put in the first passage and connected with the trigger for controlling the first passage. A muffler is put in the second passage. The muffler includes a plurality of balls.