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 impact tool includes an outer shell, an inner tube member, a supporting ring and a gas sealing ring. An outer diameter of the inner tube member is slightly less than an inner diameter of the outer shell. The inner tube member is accommodated in the outer shell. A hammer member capable of being driven by high pressure gas to move is disposed in the inner tube member. A gas room is formed between the inner tube member and the outer shell. Both the supporting ring and the gas sealing ring surround the inner tube member. The supporting ring abuts against the outer shell so that a cylindrical gap communicated with the gas room is formed between the outer shell and the inner tube member. The gas sealing ring is closely engaged with the outer shell and the inner tube member to seal the cylindrical gap.

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 slave device coupled to a master device via a bus and including a serial interface, a code generator circuit, and a control circuit is provided. The serial interface is configured to be coupled to the bus. The code generator circuit is configured to generate a unique code. The control circuit is coupled between the serial interface and the code generator circuit. In a set mode, the control circuit triggers the code generator circuit to generate the unique code. In an operation mode, the control circuit determines whether to perform commands provided by the master device according to the unique code.

Abstract: An electrical multi-purpose apparatus includes a base frame unit, and an internal combustion engine, an electric generator, an output unit, an air compressor, and a jet cleaner that are disposed on the base frame unit. The internal combustion engine includes a combustion engine motor. The electric generator is driven operably by the internal combustion engine for generating electric power. The output unit, the air compressor, and the jet cleaner are electrically connected to the electric generator. The air compressor includes an air compressor motor. The jet leaner includes a jet cleaner motor. The combustion engine motor, the air compressor motor, and the jet cleaner motor have different motor speeds.

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: A noise reduction device of compressor for gas is arranged at the inlet end of the compressor. The noise reduction device includes a noise reduction gas return housing and a plurality of gas inlet small pipes, gas inlet large pipes, gas return large pipes, and gas return small pipes, respectively arranged in the noise reduction gas return housing. The design and arrangement that the gas inlet large pipes and the gas return large pipes are respectively sleeved on the gas inlet small pipes and the gas return small pipes changes the moving path of the gas in the noise reduction gas return housing in an instantaneously reverse manner. Such moving path change mainly reduces the flow rate of the gas, so that the noise generated by the gas can be effectively reduced.

Abstract: A slave device coupled to a master device via a bus and including a serial interface, a code generator circuit, and a control circuit is provided. The serial interface is configured to be coupled to the bus. The code generator circuit is configured to generate a unique code. The control circuit is coupled between the serial interface and the code generator circuit. In a set mode, the control circuit triggers the code generator circuit to generate the unique code. In an operation mode, the control circuit determines whether to perform commands provided by the master device according to the unique code.

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 end 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. A sealed 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: 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: A transient-voltage-suppression diode structure and a manufacturing method thereof are disclosed. The structure includes a P type base substrate, an N type epitaxial layer, a P+ type implant layer, an N+ type implant layer, a plurality of deep trench portions, an interlayer dielectric layer and a first metal layer. The N type epitaxial layer is disposed on the P type base substrate. The P+ type implant layer and the N+ type implant layer are embedded within the N type epitaxial layer. The deep trench portions pass through the N type epitaxial layer and are connected with the P type base substrate. The first metal layer is disposed on the interlayer dielectric layer and connected with the P+ type implant layer, the N+ type implant layer, and the deep trench portions. The deep trench portions connected with the first metal layer are configured to form a silicon controlled rectifier.

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: 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 handheld power tool with low speed includes a housing, a middle sleeve shell and a front sleeve shell connected by threads on the exterior, and a pneumatic motor, a planet gear mechanism, a bearing, a cushion member and a fastened base in the interior. The pneumatic motor connects the planet gear mechanism through a driving shaft. The planet gear mechanism connects a grinding member located in the fastened base through a driven shaft and a flexible shaft. An outer flange portion is disposed around the fastened base. An inner flange portion is disposed on the front sleeve shell in order to press the outer flange portion while the middle sleeve shell is locked by the front sleeve shell so that the fastened base, the cushion member, the bearing, the planet gear mechanism and the pneumatic motor are fixed in a row.

Abstract: A handheld belt sander includes a main body having a motor connected with a rotating wheel and a base extending along a first straight direction. A mount is fixed to the base. A straight rod extending along a second straight direction with no bend is disposed on the mount. The second straight direction is upward from the first straight direction at a raise angle. A roller is disposed on the straight rod. A flat plate extending under the straight rod is disposed on the mount. A grinding belt encircles the rotating wheel, the roller and the flat plate and is tightened by the straight rod. A lower part of the grinding belt under the straight rod abutted against the flat plate. A space to be entered for the grinding belt formed between the straight rod and an upper part of the grinding belt above the straight rod.

Abstract: A rotational control structure of a pneumatic tool includes a housing provided with a cylinder unit. The cylinder unit has a bottom wall with two through holes and a guide post extending outwardly. The guide post has a gas passage and a gas outlet. The guide post is closely connected with a rotatable control ring leaning against the bottom wall. A sealing ring is provided between the bottom wall and the guide post. The control ring has a control passage therein. The control ring is rotatable for the control passage to communicate with one of the through holes of the bottom wall, thereby controlling the forward/reverse rotation of the pneumatic tool.

Abstract: An auxiliary grip of a hand-held power tool includes a rod body, a connecting member, and a covering layer made of an elastic material. An end portion of the rod body has a first coupling portion. Two ends of the connecting member have a connecting section and a second coupling portion, respectively. The second coupling portion of the connecting member is coupled with the first coupling portion of the rod body so that the rod body can be swayed relative to the connecting member. The covering layer covers the rod body and a part of the connecting member. The connecting section of the connecting member is connected to a power tool. When the power tool causes the auxiliary grip to vibrate due to its mechanical operation, the rod body can be swayed relative to the connecting member to reduce the vibration during the grip.

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.