Rotational control structure of pneumatic tool

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.

What is claimed is: 
     
         1 . A rotational control structure of a pneumatic tool, the pneumatic tool comprising an intake seat for communicating with an external high-pressure gas, the intake seat being connected with a cylinder unit, the cylinder unit being connected with a tool head, the cylinder unit having a rear cover, the rear cover having a first through hole and a second through hole, wherein the first through hole allows the gas to enter the cylinder unit for driving the tool head to rotate in a forward direction, and the second through hole allows the gas to enter the cylinder unit for driving the tool head to rotate in a reverse direction opposite to the forward direction; the rotational control structure comprising:
 a housing for accommodating the cylinder unit, the housing having a bottom wall leaning against the rear cover, the bottom wall having a third through hole communicating with the first through hole and a fourth through hole communicating with the second through hole; an outer periphery of the bottom wall being formed with a first annular groove, a first sealing ring being embedded in the first annular groove; the bottom wall being provided with a guide post extending outwardly from the housing, a gas passage being defined in the guide post and communicating with the intake seat, a gas outlet being provided on a side of the guide post; a second annular groove and a third annular groove being disposed at two sides of the gas outlet of the guide post respectively, a second sealing ring and a third sealing ring being embedded in the second annular groove and the third annular groove respectively;   a control ring rotatably fitted on the guide post; the control ring having an axial end surface and a radial inner annular surface, wherein the control ring is pressed by a plurality of springs disposed on the intake seat such that the end surface leans against the bottom wall through a force of the springs; the end surface being provided with an annular wall surrounding the first annular groove and pressing the first sealing ring, the inner annular surface being in close contact with the guide post to surround the second annular groove and the third annular groove and press the second sealing ring and the third sealing ring; a control passage being defined in the control ring, a control inlet being formed on the inner annular surface, a control outlet being formed on the end surface; the control ring being rotatable in a rotation range between a first position and a second position where the control inlet is always in communication with the gas outlet, wherein when the control ring is rotated to the first position, the control outlet communicates with the third through hole; when the control ring is rotated to the second position, the control outlet communicates with the fourth through hole.   
     
     
         2 . The rotational control structure of the pneumatic tool as claimed in  claim 1 , wherein a spacer is disposed between the control ring and the intake seat, and the spacer is pressed by the springs to lean against the control ring. 
     
     
         3 . The rotational control structure of the pneumatic tool as claimed in  claim 1 , wherein the housing is provided with an outer casing, a bottom end of the outer casing leans against the annular wall of the control ring; the bottom end of the outer casing is provided with a limiting recess, the annular wall is provided with a limiting block inserted into the limiting recess, and the limiting block leans against either end of the limiting recess when the control ring is rotated to the first position or the second position.