Abstract: A safety cover used in a sand grinder is disclosed to include a cover body rotatably mounted at the base of the sand grinder around the sand wheel and having equiangularly spaced oval locating holes, a positioning device selectively engaged into one of the oval locating holes, and a switching lever mounted at the base and biasable between a locking position where an abutment portion of the switching lever is abutted against the positioning device to lock the positioning device in one oval locating hole and an unlocking position where a bearing portion of the switching lever faces toward the positioning device for enabling the positioning device to be disengaged from the respective oval locating hole.

Abstract: A pneumatic tool includes a housing that contains an installation tunnel, an air supplying channel and first and second air inlets, a control valve installed in the installation tunnel for shifting among first, second and third positions; a controller that is mounted on the control valve and has two paddles; a pushing rod that passes through the controller and the control valve; and a trigger that is attached to the pushing rod. The pneumatic tool provides the controller for a user to selectively operate with his/her left hand or right hand to perform forward/reverse switching and speed adjustment.

Abstract: An impact device for power transmission includes an impact unit and a hydraulic pressure adjusting unit. The impact unit has a hydraulic cylinder which is installed with a piston assembly and an output shaft therein for outputting torque through the output shaft by utilizing a hydraulic pressure provided in the hydraulic cylinder. The hydraulic pressure adjusting unit is disposed in the hydraulic cylinder and operative to adjust the hydraulic pressure of the hydraulic cylinder. Therefore, the impact device for power transmission can generate a hydraulic torque pulse, and the magnitude of the output torque can be adjusted by the hydraulic pressure adjusting unit.

Abstract: A hydraulic pulse tool includes a power supply unit, a drive unit electrically connected to the power supply unit, a hydraulic pulse torque generating unit coupled to the drive unit and rotatable by the drive unit to produce impacts for causing the drive to produce an electric current change, and a control unit for judging the electric current change and controlling the operation of the drive unit subject to the judgment result. Subject to the above-stated technical characteristics, the hydraulic pulse tool, in addition to the shutoff function, can reduce errors in judgment and achieve multi-stage torque output control.

Abstract: A switch assembly includes a circuit board mounted in the housing of an electric tool and carrying multiple magnetic sensor components, a first button having hooks slidably coupled to the circuit board and a press portion exposed to the outside of the housing for pressing by a user and a first magnetic member mounted at the press portion and movable with the first button relative to the housing to induce and change the magnetic flux of one magnetic sensor component, and a second button mounted in the housing and movable back and forth relative to the housing and carrying a second magnetic member that is movable with the second button to induce and change the magnetic flux of the other magnetic sensor component.

Abstract: An electric riveter capable of rivet pre-pulling includes an operating unit, a controlling unit, a driving unit, and a clamping unit. The controlling unit controls the driving unit according to the way in which a user operates the operating unit, the clamping unit is driven by the driving unit to move between an initial position, a pre-pulling position, and a severing position. The operation method for the electric riveter entails: providing a rivet when the clamping unit is at the initial position; operating the operating unit in a first operation mode to move the clamping unit to the pre-pulling position and clamp the rivet; and operating the operating unit in a second operation mode to move the clamping unit to the severing position and sever the rivet. Accordingly, the rivet is prevented from falling off during the operation process, thereby enhancing ease of use of the electric riveter.

Abstract: Used in a pneumatic tool, a switch includes a valve seat set in an air intake passage and movable into contact with or away from a gas control member and defining an air hole, and a valve rod inserted through the air hole of the valve seat. When the positioning portion of the valve rod is stopped against the valve seat and the valve seat is stopped against the gas control member, the air intake passage is blocked. When the valve rod is biased relative to the valve seat, the positioning portion is moved away from the air hole of the valve seat for allowing a compressed gas to pass through the air hole, and when the valve rod is biased further to carry the valve seat away from the gas control member, the compressed gas is allowed to pass between the valve seat and the gas control member.

Abstract: A riveting unit is assembled with an electric rivet gun, including a transmission unit, a clamping jaw having a locating portion driven by the transmission unit to be moveable between a first position and a second position, a first sensor detecting whether the locating portion of the clamping jaw is located at the first position, and a second sensor detecting whether the locating portion of the clamping jaw is located at the second position. When the locating portion of the clamping jaw is located at the first position, a blind rivet can be installed in the clamping jaw, and when the locating portion of the clamping jaw is located at the second position, the blind rivet can be ejected, and meanwhile the second sensor can allow the transmission unit to stop the movement of the clamping jaw, thereby preventing the clamping jaw from moving backwards excessively.

Abstract: A power ratchet head is composed of a main body and a reinforcing rib. The main body is hollow inside and includes a pair of stopping portions, a receiving space, and a first through hole. The stopping portions are spaced from each other, extending outward from one end of the main body. The receiving space is formed between the two stopping portions. The first through hole runs through one of the stopping portions. The reinforcing rib is connected between the two stopping portions and located at free ends of the stopping portions, having a width that is smaller than the radius of the first through hole. The reinforcing rib is connected with the free ends of the stopping portions to structurally reinforce the main body, such that the stopping portions are not subject to outward deformation and the working life of the power ratchet head can be enhanced.

Abstract: A riveting unit is assembled with an electric rivet gun, including a transmission unit, a clamping jaw having a locating portion driven by the transmission unit to be moveable between a first position and a second position, a first sensor detecting whether the locating portion of the clamping jaw is located at the first position, and a second sensor detecting whether the locating portion of the clamping jaw is located at the second position. When the locating portion of the clamping jaw is located at the first position, a blind rivet can be installed in the clamping jaw, and when the locating portion of the clamping jaw is located at the second position, the blind rivet can be ejected, and meanwhile the second sensor can allow the transmission unit to stop the movement of the clamping jaw, thereby preventing the clamping jaw from moving backwards excessively.

Abstract: A riveting tool with a rivet rod expelling function is disclosed to include a tool body having a base and a grip extended from the base. The base has a rivet passage defined therein and an opening located on the peripheral wall thereof in communication with the passage and adjacent to the grip for quick discharge of each broken rivet rod during the riveting operation.

Abstract: A pneumatic tool capable of reducing noise includes a housing having an air intake passage and an exhaust passage, a pneumatic unit mounted in the housing, and an air-guiding member detachably mounted in the exhaust passage. The air-guiding member has an end plate with at least one hole and a lateral wall mounted on a periphery of the end plate to define an air-guiding chamber therebetween and extending divergently from the end plate and provided with at least one hole. Thus, when compressed air goes through the pneumatic tool from the air intake passage to the exhaust passage, it goes into the air-guiding chamber through the holes of the end plate and the lateral wall, and then goes out of the housing.

Abstract: A motor overcurrent protection device connectable to a motor. The motor has a rotary shaft and a controlling port. The motor overcurrent protection device includes a sensing unit, a driving unit and a controlling unit. The sensing unit includes a magnetic block arranged on a circumference of the rotary shaft and a Hall device positioned beside the rotary shaft. The magnetic block is rotatable along with the rotary shaft to be instantaneously aligned with the Hall device. The driving unit is electrically connected with the controlling port of the motor. The controlling unit is electrically connected with the sensing unit and the driving unit. When the motor operates, each time the magnetic block is aligned with the Hall device, the Hall device outputs a pulse signal which is stored in the controller of the controlling unit. All the pulse signals are summed up in a preset sensing time of the controller.

Abstract: A pressure regulating mechanism for use in a pneumatic tool includes a first relief valve and a second relief valve. The pneumatic tool includes a housing having an air intake passage, an exhaust passage and a connecting passage in air communication between the air intake passage and the exhaust passage, an air cylinder unit mounted in the housing. The air cylinder unit has an air chamber, an air passage in air communication between the air chamber and the air intake passage, and a through hole in air communication with the air passage. The first relief valve is for mounting in the connecting passage adjacent to the air cylinder unit. The second relief valve is for mounting in the through hole of the air cylinder unit. The pressure regulating mechanism maintains the air pressure inside the pneumatic tool stable.

Abstract: 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.

Abstract: A toothed ring connecting structure of a power tool, including: a main body having a first opening and a second opening; a motor accommodated in the main body and having an output shaft extending from a first end of the motor; a fixing cap having a body section, a first end of the body section being fixed with the first end of the motor, the body section being formed with a shaft hole through which the output shaft of the motor is coaxially fitted, a second end of the body section being formed with a fixing thread hole, the fixing thread hole inward axially extending from the second end of the body section to coaxially communicate with the shaft hole; a toothed ring having a first end extending into the first opening of the main body and a second end extending out from the main body, the first end being formed with a first thread for screwing into the fixing thread hole, the second end being formed with a second thread; an operating end piece having a connecting end; and an adjustment threaded bush, one end o