Patent Publication Number: US-6338389-B1

Title: Air outlet regulating mechanism for pneumatic tool

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an air outlet regulating mechanism for pneumatic tool, and more particularly to a mechanism for regulating the passage via which air is discharged from the pneumatic tool, so that either an increased torque force or a reduced air discharge noise of the pneumatic tool could be obtained depending on actual needs. 
     In a conventional pneumatic tool, there is an air outlet hole provided at a lower part of a body of the tool, so that air could be discharged from the air outlet hole when the pneumatic tool is in operation. When the air is discharged from the air outlet hole, a considerably large explosive sound (or burst noise) is produced. Such explosive sound forms a serious noise when the pneumatic tool is used indoors. A means to reduce the noise is to provide an extended air-out passage in the pneumatic tool. Such extended air-out passage, however, reduces a torque force of the pneumatic tool and is therefore not ideal for use. 
     SUMMARY OF THE INVENTION 
     A primary object of the present invention is to provide an air outlet regulating mechanism for a pneumatic tool, so that air in the pneumatic tool could be selectively discharged via different passages to either increase the torque force of the tool or reduce an air discharge noise thereof, depending on actual needs in different working sites. 
     To achieve the above and other objects, the air outlet regulating mechanism of the present invention mainly includes a long vertical and a short horizontal air-out passage provided in a handle and a body of the pneumatic tool, respectively, and a regulating valve mounted in the pneumatic valve at a convergence point of the two air-out passages and a body air-out passage typically provided in the pneumatic tool. The regulating valve includes a knob accessible from outside of the pneumatic tool and a long stopper movable between a first and a second position through turning of the knob. The long stopper in the first position fully blocks the vertical air-out passage for air in the pneumatic tool in operation to discharge via the short horizontal air-out passage to increase the torque force of the pneumatic tool. And, The long stopper in the second position fully blocks the horizontal air-out passage for air in the pneumatic tool in operation to discharge via the long vertical air-out passage to lower the noise produced during discharging air from the pneumatic tool. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The structure and the technical means adopted by the present invention to achieve the above and other objects can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein 
     FIG. 1 is a perspective of a pneumatic tool including an air outlet regulating mechanism of the present invention; 
     FIG. 2 is a partially sectioned view of the pneumatic tool of FIG. 1 showing the location of the air outlet regulating mechanism in the pneumatic tool; 
     FIG. 3A is a side view of a regulating valve of the air outlet regulating mechanism of the present invention in a first position; 
     FIG. 3B is a cross sectional view taken on line A-A′ of FIG. 3A; 
     FIG. 3C is a side view of the regulating valve of the air outlet regulating mechanism of the present invention in a second position; 
     FIG. 3D is a cross sectional view taken on line B-B′ of FIG. 3C; 
     FIG. 4A is a fragmentary front view of the pneumatic tool of FIG. 1 with the regulating valve in the first position; 
     FIG. 4B is a front view of the regulating valve of the present invention in the first position; 
     FIG. 4C is a fragmentary left side view of the pneumatic tool of FIG. 1 with the regulating valve in the first position; 
     FIG. 5A is a fragmentary front view of the pneumatic tool of FIG. 1 with the regulating valve in the second position; 
     FIG. 5B is a front view of the regulating valve of the present invention in the second position; and 
     FIG. 5C is a fragmentary left side view of the pneumatic tool of FIG. 1 with the regulating valve in the second position. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to FIGS. 1 and 2 in which a pneumatic tool  1  including an air outlet regulating mechanism of the present invention is shown. The air outlet regulating mechanism  1  mainly includes a vertical air-out passage  12  provided in a handle portion  10  of the pneumatic tool  1  with an air outlet  121  of the air-out passage  12  provided at a lower end of the handle portion  10 , a horizontal air-out passage  13  that is shorter than the vertical air-out passage  12  and is provided in a lower front area of a body portion  11  of the pneumatic tool  1  with an air outlet  131  of the air-out passage  13  provided at a lower front of the body portion  11 , and a regulating valve  2  mounted in the pneumatic tool  1  at a convergence point of the vertical and the horizontal air-out passages  12 ,  13  as well as a body air-out passage  14  provided in the body portion  11 . 
     Please refer to FIG. 3A that is a side view of the regulating valve  2 . As shown, the regulating valve  2  includes two symmetrical disc portions  21  and  22 , a knob portion  23  connected to the disc portion  21  that is located closer to an outer side of the pneumatic tool  1  than the other disc portion  22 , and a long stopper  24  having a substantially semicircular cross section and extended between the two disc portions  21 ,  22  to connect them to one another. Both the disc portions  21  and  22  have a diameter-reduced middle portion  211 ,  221 , at where the regulating valve  2  is fixedly mounted in the pneumatic tool  1  at the convergence point of the vertical, the horizontal, and the body air-out passages  12 ,  13  and  14 , respectively. The knob portion  23  is rotatably located outside the body portion  11  of the pneumatic tool  1 . By turning the knob portion  23 , it is possible to move the long stopper  24  between a first and a second position. FIG. 3B is a cross sectional view taken on line A-A′ of FIG. 3A, showing the long stopper  24  in the first position. FIG. 3C is another side view of the regulating valve  2  with the knob portion  23  being turned to locate the long stopper  24  in the second position. And, FIG. 3 d  is a cross sectional view taken on line B-B′ of FIG. 3C, showing the long stopper  24  in the second position. 
     When the pneumatic tool  1  is used outdoors or in a place at where noise from the pneumatic tool  1  in operation is not a consideration, an operator may turn the knob portion  23  to a horizontal position as shown in FIG. 4A, so as to locate the long stopper  24  in the first position as shown in FIGS. 4B and 4C. The long stopper  24  in the first position fully blocks an inner end of the vertical air-out passage  12 , so that air from the body air-out passage  14  in the pneumatic tool  1  is guided into the horizontal air-out passage  13  and discharged via the air outlet  131 . Since the horizontal air-out passage  13  is short, discharge of air via the horizontal air-out passage  13  may advantageously increase a torque force of the pneumatic tool  1 . 
     When the pneumatic tool  1  is used indoors or in a closed place at where noise from the pneumatic tool  1  in operation is a consideration, the operator may turn the knob portion  23  to a vertical position as shown in FIG. 5A, so as to locate the long stopper  24  in the second position as shown in FIGS. 5B and 5C. The long stopper  24  in the second position fully blocks an inner end of the horizontal air-out passage  13 , so that air from the body air-out passage  14  in the pneumatic tool  1  is guided into the vertical air-out passage  12  and discharged via the air outlet  121 . Since the vertical air-out passage  12  is long, discharge of air via the vertical air-out passage  12  requires extended time that advantageously lowers the noise produced during discharge of air but disadvantageously reduces the torque force of the pneumatic tool  1 . Nevertheless, the pneumatic tool  1  could still work normally. 
     With the vertical and the horizontal air-out passages  12 ,  13  provided in the handle portion  10  and the body portion  11  of the pneumatic tool  1 , respectively, and the regulating valve  2  provided in the pneumatic tool  1  at the convergence point of the vertical and the horizontal air-out passages  12 ,  13  as well as the body air-out passage  14 , air in the pneumatic tool  1  in operation could be selectively discharged via the vertical or the horizontal air-out passage  12  or  13  through turning the regulating valve  2 , so as to either lower the noise during air discharging or increase the torque force of the pneumatic tool  1 , depending on different considerations in the working sites.