A pneumatic tool includes: a drive mechanism which is configured to be driven by compressed air of a first pressure: and a valve mechanism which is configured to be actuated by compressed air of a second pressure, which is higher than an atmospheric pressure and lower than the first pressure, and which is configured to switch whether or not to supply the compressed air of the first pressure to the drive mechanism.

A pneumatic tool includes: a drive mechanism which is configured to be driven by compressed air of a first pressure: and a valve mechanism which is configured to be actuated by compressed air of a second pressure, which is higher than an atmospheric pressure and lower than the first pressure, and which is configured to switch whether or not to supply the compressed air of the first pressure to the drive mechanism.

A valve seat has a first valve plate and a second valve plate detachably connected to the first valve plate. The first valve plate has a first trough and at least one pair of first dents, each pair including two first dents capable of respectively forming two first passages with a housing of a pneumatic hammer. The second valve plate has a second trough, at least one pair of second dents, at least one inlet tunnel, and at least two inlet channels. The second trough faces to and communicates with the first trough. Each pair of second dents includes two second dents capable of respectively forming two second passages with the housing. Each inlet tunnel is formed through the second valve plate and communicates with the two second passages. The at least two inlet channels communicate with the second trough and the at least one inlet tunnel.

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.

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.

A prior art powered wrist pin knocker is improved with a new plunger that prevents wobbling. The new plunger responds to a return vacuum pressure. The improved plunger is symmetrical along a longitudinal axis. New embodiments include a new side mount valve head to reduce length, a remote air controller and a variable length cylinder for the cannon. The new valve head is a simplified valve head assembly that adapts to an end of the cannon mount or a side mount or a remote mount. Another embodiment provides a stand for a surface mount application. This embodiment can have an extended piston for loosening tail bearings down a long channel. A manual return embodiment can use a rod to manually return the plunger to the proximal end for another firing cycle.

A prior art powered wrist pin knocker is improved with a new plunger that prevents wobbling. The new plunger responds to a return vacuum pressure. The improved plunger is symmetrical along a longitudinal axis. New embodiments include a new side mount valve head to reduce length, a remote air controller and a variable length cylinder for the cannon. The new valve head is a simplified valve head assembly that adapts to an end of the cannon mount or a side mount or a remote mount. Another embodiment provides a stand for a surface mount application. This embodiment can have an extended piston for loosening tail bearings down a long channel. A manual return embodiment can use a rod to manually return the plunger to the proximal end for another firing cycle.

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.

In an improved air inlet valve assembly, a flow of air along a first or second flow path may be controlled by a position of air inlet guide surfaces of a rotatable valve relative to air inlet guide slots of a fixed valve sleeve. Air flowing along the first flow path may rotate a motor in a first direction to operate the tool in a forward mode. Air flowing along the second flow path may rotate the motor in the second direction to operate the tool in a reverse mode. In the forward mode, as air flows along the first flow path, air may be discharged along a primary discharge path, with a portion of the second flow path providing a secondary discharge path. In the reverse mode, as air flows along the second flow path, air may be discharged along the primary discharge path, with a portion of the first flow path providing the secondary discharge path.

In an improved air inlet valve assembly, a flow of air along a first or second flow path may be controlled by a position of air inlet guide surfaces of a rotatable valve relative to air inlet guide slots of a fixed valve sleeve. Air flowing along the first flow path may rotate a motor in a first direction to operate the tool in a forward mode. Air flowing along the second flow path may rotate the motor in the second direction to operate the tool in a reverse mode. In the forward mode, as air flows along the first flow path, air may be discharged along a primary discharge path, with a portion of the second flow path providing a secondary discharge path. In the reverse mode, as air flows along the second flow path, air may be discharged along the primary discharge path, with a portion of the first flow path providing the secondary discharge path.