Abstract: A handheld belt sander with improved structure includes a main body having a rotating wheel and a mount. A support rod with a front roller is disposed on the mount. A support member with a rear roller is disposed on the mount. A tightened grinding belt encircles the rotating wheel, the front roller and the rear roller. A space is formed between the support rod and a part of the grinding belt between the front roller and the rear roller so that the grinding belt moves into the space after being pressed. Two side rollers are disposed on two sides of the support member to be adjacent to the grinding belt and are separated from the grinding belt by a gap in order to block the grinding belt from separating from the rear roller.

Abstract: A vibration reducing structure of pneumatic hammer includes a handle having a concave room with a bottom wall and an air inlet channel communicating with the concave room. A control valve is disposed in the air inlet channel. A movable inner tube shell is accommodated in an outer tube shell coupled with the concave room and extends a rear bucket portion into the concave room. A movable hammer member, an air inlet valve for activating the hammer member and a hole communicating the air inlet channel to the air inlet valve are disposed in the inner tube shell. An air room is formed between the bottom wall and an end wall of the inner tube shell. A communicating channel communicates the air inlet channel to the air room for air with high pressure entering the air room.

Abstract: An air impact tool includes an inner tubular member that is connected to the barrel. The inner tubular member has an annular wall and a cavity. The annular wall has exhaust hole. An air flow channel communicating with the air flow control valve and the cavity is defined inside the annular wall. The air flow channel is formed with a first air inlet. A hammer is in the cavity. The hammer is in close contact with the annular wall. A cylindrical gap is defined between a middle section of the hammer and the annular wall. The hammer has an exhaust passageway communicating with the cavity and the cylindrical gap. When the compressed air is injected into the cavity from the first air inlet, the hammer is pushed back, and the compressed air is exhausted via the exhaust passageway, the cylindrical gap and the exhaust hole in sequence.

Abstract: A pneumatic impact tool having a vibration reducing structure includes a handle with a bucket member and a directional control valve. A tube member including a cylindrical wall and a chamber is coupled with the bucket member. The chamber is divided into a front and a rear chamber portion by a hammer member. Gas may be guided into the front or the rear chamber portion by the directional control valve. A vent is disposed on the cylindrical wall. An exhaust channel which communicates with the front chamber portion and not communicates with the rear chamber portion is disposed on an outer peripheral surface of the hammer member. The hammer member is pushed to return if gas is guided into the front chamber portion. Gas in the front chamber portion is exhausted when the exhaust channel communicates with the vent.

Abstract: A joint fixing structure of a hand-held power tool includes a fixing base connected with a tool head. Two opposite sides of the fixing base have through holes with movable balls. The fixing base is surrounded by a C-shaped ring with two protrusions. The C-shaped ring is surrounded by a control ring that has an circular outer surface and an inner surface provided with two recesses. The control ring is operated to rotate relative to the C-shaped ring between an unlocked position and a locked position. When in the unlocked position, the protrusions go into the recesses, making the C-shaped ring not press the balls so that the tool head can be pivoted freely. When in the locked position, the tool head is locked by the balls being pressed by the deformation of the C-shaped ring due to the motion of the protrusions out of the recesses.

Abstract: An expandable handheld pneumatic belt grinder includes a body, an expansion component and an operation component. The body has a receiving space, a pneumatic motor, and a rotating wheel driven by the pneumatic motor. The expansion component has an expansion pipe and an expansion rod which are connected. The expansion rod is coupled to the receiving space. The operation component has a support rod with one end carrying a driven wheel and the other end coupled to the receiving space or expansion pipe. A grinding belt fits around the driven wheel and rotating wheel collectively. A user changes the distance between the rotating wheel and driven wheel by choosing between two options: coupling the support rod of operation component and the receiving space; and coupling the expansion rod of expansion component and the receiving space, and then coupling the support rod of operation component and the expansion pipe.

Abstract: A silencing mechanism of a pneumatic tool, disposed in an exhaust pipe of the pneumatic tool, includes an annular wall extending along the exhaust pipe, enclosing a first space, and having a plurality of first slits whereby the first space and a second space formed between the annular wall and a pipe wall of the exhaust pipe are in communication with each other; and at least one flange disposed around the annular wall and protruding radially to partition the second space into a plurality of segments, wherein the at least one flange each has a plurality of second slits whereby adjacent segments are in communication with each other. A gas current not only flows freely between the first and second spaces through the first slits but also flows within the second space and passes the second slits, thereby reducing noise.

Abstract: A handheld power tool includes a main body that contains a driving unit having a driving shaft that passes through a connecting seat and a connector and is connected to a workpiece. The connector has a ball seat swingably received in a ball socket of the connecting seat. A clamp mounted around the connecting seat serves to limit retaining balls arranged between the ball seat and the connecting seat. The connecting seat has an end cap. After the connector is angled as desired, the adjusting member constricts the clamp, and radially presses the retaining balls against the ball seat through the spring leaf, thereby fastening the connector firmly and preventing the workpiece from jigging during operation.

Abstract: A pneumatic tool has a hollowed main body. One end of the main body is assembled with a pneumatic motor having a transmission shaft inserted into the main body. The other end of the main body is assembled with a connecting member being slidable along an axial direction of the main body. One end of the connecting member forms a connecting portion, and the other end of the connecting member forms a knife assembling portion. A driving gear is rotatably assembled in the main body and engaged with the transmission shaft. A protruding post is assembled on a portion of the driving gear biasing from an axis of the driving gear. A linking bar has a first end and a second end opposite to the first end. The first end is pin-jointed to the protruding post, and the second end is pin-jointed to the connecting portion of the connecting member.

Abstract: The present disclosure illustrates an eraser wheel assembly structure in which an eraser wheel body is fastened with a shell cover by a fastener, so the eraser wheel body can be driven by the grinding tool to rotate for removing glue. The eraser wheel body is disposed in the shell cover and has a plurality of glue removing blocks. The shell cover has a plurality of positioning studs and configured to respectively insert positioning holes of the eraser wheel body. The shell cover has a blocking wall facing a peripheral edge of the disc-based base and a gap to tolerate a radial extension of the disc-shaped base during operation, so as to prevent the peripheral edge of the disc-shaped base from being escaped from the blocking wall and unable back to its former position because of no gap tolerable for the radial extension of deformed disc-shaped base.

Abstract: A forward/reverse rotation device of a pneumatic tool comprising a clutch switch that can be pressed towards the inside of a switching valve to separate a steering switch from its connection with a positioning element, and the steering switch is turned from a side of a handle of the pneumatic tool to the other opposite side, and the clutch switch is bounced to resume its original position by the support of an elastic element, so as to connect the steering switch with the positioning element again. A sleeve portion of the steering switch is coaxially and pivotally installed at a center rod of the clutch switch, and the steering switch is turned between both sides of the handle and maintained to be pivotally turned on the center rod.

Abstract: An impact wrench with an improved redirection switch includes a housing, a motor shell, an on/off bar set, and a redirection switch. The pushing bar of the redirection switch and the redirection valve are connected in tandem along the same horizontal line. The rotational axis of the rotating redirection valve is perpendicular to the penetrating axis of the on/off bar set, instead of the same penetrating axis line. Therefore, the invention achieves the redirection effect without increasing the volume of its handle.

Abstract: A rotation speed control device for air tools and the method thereof are disclosed. A shell base is disposed with a forward air inlet and a reverse air inlet. A back cover is connected to one side of the shell base. The back cover has a forward flow path in communications with the forward air inlet and a reverse flow path in communications with the reverse air inlet. The forward flow path has a rotation space whose one side has a pressure release hole in communications with the ambient space. A rotation speed control element having a stopping part that can close the pressure release hole is disposed in the rotation speed. The rotation speed control element rotates to control the aperture size of the pressure release hole, thereby adjusting the airflow entering the forward flow path.

Abstract: An improved structure of a pneumatic impact wrench includes a main body, a plastic casing provided for fixing a motor casing and a motor module, the motor module having a cylinder for installing a rotor, the rotor being extended from an axle and supported by a bearing, the motor casing having an external case with a hardness greater than that of the plastic casing, and the external case being hollow and penetrating both ends to form a chamber for accommodating and installing a cylinder, and the external case having a stop ring protruded from an internal wall of the chamber and provided for blocking the cylinder, and an external case cover installed at a rear end of the external case for coupling and covering the external case cover.

Abstract: A grinding wheel including a ring-shaped wheel, a first fixing cap, a second fixing cap and a buffer member. The ring-shaped wheel has a fixing section and a working section formed along outer circumference of the fixing section. The first and second fixing caps are respectively mounted on two sides of the fixing section. The buffer member is positioned between the first and second fixing caps for reducing shock produced in operation. The circumference of the buffer member is formed with multiple movable vanes. When the grinding wheel is rotated at high speed, the centrifugal force will deform the movable vanes of the buffer member to lean on the ring-shaped wheel for supporting the working section thereof.