Patent Publication Number: US-7594549-B2

Title: Rotating direction switching device for a pneumatic tool

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a pneumatic tool, and more particularly to a pneumatic tool having a rotating direction switching device. 
   2. Description of the Prior Art 
   Among all kinds of locking members, screws and nuts are most widely used because of their advantages. Therefore, tools for rotating the screws and nuts also have a large space to develop. These tools should be rotatable so as to rotate screws and nuts. However, a conventional tool usually is only able to rotate in a single direction, so two tools with different rotating direction should be prepared during work, and users have to alternately use the two tools, thus wasting time. 
   In order to solve the abovementioned problem of the conventional tool and make screwing and unscrewing operation more convenient, a pneumatic wrench  10  having the function of switching rotating direction is developed, as shown in  FIG. 1  and  FIG. 2 . A clockwise rotation air hole  11  and a counterclockwise rotation air hole  12  are defined in the pneumatic wrench  10  respectively. A switch  13  provided with a through hole  14  for cooperating with the clockwise rotation air hole  11  and the counterclockwise rotation air hole  12  is pivotally disposed in the pneumatic wrench  10 . By turning the switch  13 , the through hole  14  can be selectively connected to the clockwise rotation air hole  11  or the counterclockwise rotation air hole  12  to make the pneumatic wrench rotate in clockwise or counterclockwise directions, achieving the function of switching the rotating direction. 
   Generally speaking, the pneumatic tool  10  has the function of switching rotation direction, but it is inconvenient to use. The reason is that users have to control the switch  13  of the pneumatic tool  10  with the thumb, while the thumb is not a nimble finger and is not used frequently, so it is quite inconvenient to turn the switch  13  with the thumb. In addition, users have to choose at which side of the pneumatic tool  10  the switch  13  is to be fixed according to their dominant hands, so two switches should be prepared to be fixed at different sides of the pneumatic tool  10  for different users with different dominant hands. Therefore, it is inconvenient. 
   The present invention has arisen to mitigate and/or obviate the afore-described disadvantages. 
   SUMMARY OF THE INVENTION 
   The primary objective of the present invention is to provide a rotating direction switching device that utilizes a switch to drive an air inlet valve, and simplifies the operation of switching rotating direction, and is more comfortable and convenient for a single hand to operate. 
   The secondary objective of the present invention is to provide a rotating direction switching device that is designed for different dominant hands of users, so that they can operate the rotating direction switching device easily no matter they are left hand or right hand dominated. 
   The rotating direction switching device for the pneumatic tool in accordance with the present invention comprises an air inlet valve and a switch. The air inlet valve is pivotally and rotatably disposed in the pneumatic tool, and a passive portion is defined on a side of the air inlet valve. The switch is fixed in the pneumatic tool and extends out of two sides of the pneumatic tool respectively. The direction of the two ends of the switch is perpendicular to the rotating axis of the air inlet valve. A driving portion is formed on the switch for engaging with the passive portion of the air inlet valve. The switch utilizes the driving portion to drive a passive portion of the air inlet valve and consequently drive the air inlet valve to rotate, thus switching the rotating direction of the pneumatic tool. 
   The rotating direction switching device for the pneumatic tool in accordance with the present invention utilizes the driving portion of the switch to drive a passive portion of the air inlet valve and consequently drive the air inlet valve to rotate, thus switching the rotating direction of the pneumatic tool. Since the switch is operated by index and thumb, the present invention is more convenient to operate and is more comfortable. No matter users who are right hand or left hand dominated, the rotating direction of the pneumatic tool can be switched very easily. 
   The passive portion of the air inlet valve in accordance with the present invention can be an engaging structure, and the driving portion of the switch can be a protruding pole for engaging with the passive portion; the passive portion can as also be a protruding pole, and the driving portion of the switch can be a concave structure for engaging with the passive portion, or the passive portion and the driving portion can be toothed structures for engaging with each other. 
   In addition, the air inlet valve is provided with two passive portions in the form of protruding poles, and the switch is made up of two subassemblies, which extend out of two sides of the pneumatic tool, respectively. Each of the subassemblies is provided with a driving portion that is an engaging structure for engaging with each of the passive portions. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a conventional pneumatic tool; 
       FIG. 2  is a partial cross sectional view of the conventional pneumatic tool; 
       FIG. 3  is a perspective view of showing that the rotating direction switching device in accordance with the embodiment is disposed in the pneumatic tool; 
       FIG. 4  is an exploded view of showing that the rotating direction switching device in accordance with the embodiment is disposed in the pneumatic tool; 
       FIG. 5  is a partial cross sectional view of showing that the rotating direction switching device in accordance with the embodiment is fixed in the pneumatic tool; 
       FIG. 6  is a perspective view of showing that the air inlet valve and the switch in accordance with the embodiment is fixed in the pneumatic tool and is pushed to one side; 
       FIG. 7  is a perspective view of showing that the air inlet valve and the switch in accordance with the embodiment is fixed in the pneumatic tool and is pushed to the other side; 
       FIG. 8  is a cross sectional view of showing that the air inlet valve in accordance with the embodiment is received in the valve sleeve. 
       FIG. 9  is a perspective view of showing that the clockwise air inlet hole of the air inlet valve is aligned and connected with the clockwise rotation air hole of the valve sleeve in accordance with the embodiment; 
       FIG. 10  is a perspective view of showing that the counterclockwise air inlet hole of the air inlet valve is aligned and connected with the counterclockwise rotation air hole of the valve sleeve in accordance with the embodiment; 
       FIG. 11  is a perspective view of showing that a protruding pole structured passive portion engages with a concave structured driving portion in accordance with another embodiment; 
       FIG. 12  is perspective view of showing that a toothed passive portion engages with a toothed driving portion in accordance with another embodiment; and 
       FIG. 13  is perspective view of showing that two protruding pole structured passive portions engages with two concave structured driving portions in accordance with another embodiment. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will be more clear from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention. 
   Referring to  FIGS. 3-8 , a rotating direction switching device for a pneumatic tool in accordance with the present invention is disposed between a valve seat B and a trigger C of the pneumatic tool A. The valve seat B is provided with a controlling shaft B 1  and a valve sleeve B 2 , and the valve sleeve B 2  is provided with a clockwise rotation air hole B 3  and a counterclockwise rotation air hole B 4  for cooperating with a clockwise rotation air inlet passage D and a counterclockwise rotation air inlet passage E of the pneumatic tool A, respectively. 
   An embodiment of the rotating direction switching device comprises an air inlet valve  21  and a switch  22 . 
   The air inlet valve  21  is a hollow tubular structure pivotally and rotatably inserted on the controlling shaft B 1  of the valve seat B, and is received in the valve sleeve B 2 . A clockwise air inlet hole  211  and a counterclockwise inlet hole  212  are defined in the air inlet valve  21  for cooperating with the clockwise rotation air hole B 3  and the counterclockwise rotation air hole B 4  of the valve sleeve B 2 , respectively. A passive portion  213  is defined on a side of the air inlet valve  21 , which is an engaging structure in this embodiment. 
   The switch  22  is fixed in the valve seat B and two ends of the switch  22  extend out of the valve seat B. The direction of the two ends of the switch  22  is perpendicular to the rotating axis of the air inlet valve  21 . A driving portion  221  is formed in the middle section of the switch  22  for engaging with the passive portion  213  of the air inlet valve  21 . In the embodiment, the driving portion  221  is a protruding pole. The driving portion  221  of the switch  22  engages with the passive portion  213  of the air inlet valve  21  to drive the passive portion  213 , so that the switch  22  can drive the air inlet valve  21  to rotate, as shown in  FIG. 6  and  FIG. 7 . 
   The operation of switching the rotating direction is shown in  FIG. 9  and  FIG. 10 . Pushing the switch  22  to move in a direction perpendicular to the rotating axis of the air inlet valve  21 , consequently, the driving portion  221  drives the passive portion  213  of the air inlet valve  21 , so that the air inlet valve  21  is driven to rotate. When the air inlet valve  21  rotates to a position at which the clockwise air inlet hole  211  is aligned and connected with the clockwise rotation air hole B 3  of the valve sleeve B 2 , air can be guided in the clockwise rotation air inlet passage D to make the pneumatic tool A rotate clockwise. If the air inlet valve  21  rotates to a position at which the counterclockwise air inlet hole  212  is aligned and connected with the counterclockwise rotation air hole B 4 , air can be guided in the counterclockwise rotation air inlet passage E to make the pneumatic tool A rotate counterclockwise. By such arrangements, the rotating direction of the pneumatic tool A can be easily switched between the clockwise rotating mode and the counterclockwise rotating mode. 
   Other embodiments of the passive portion  213  of the air inlet valve  21  and the driving portion  221  of the switch  22  are shown in  FIGS. 11-12 , which are described in detail below. The passive portion  213  is a protruding pole, and the driving portion  221  is a concave structure for engaging with the passive portion  213 . Besides, the passive portion  213  and the driving portion  221  can be toothed structures for engaging with each other In addition, as shown in  FIG. 13 , the air inlet valve  21  is provided with two passive portions  213  in the form of protruding poles, and the switch  22  is made up of two subassemblies (not shown), which extend out of two sides of the pneumatic tool A, respectively. Each of the subassemblies is provided with a driving portion  221  that is an engaging structure for engaging with each of the passive portions  213 . 
   As compared with a conventional rotating direction switching device for a pneumatic tool, users only need to push the switch  22  of the present invention to move in a direction perpendicular to the rotating axis of the air inlet valve  21  to switch between the clockwise rotating mode and the counterclockwise rotating mode. The driving portion  221  drives the passive portion  213  of the air inlet valve  21 , so that the air inlet valve  21  is driven to rotate. Therefore, the rotating direction of the pneumatic tool A can be easily switched between the clockwise rotating mode and the counterclockwise rotating mode by pushing the switch  22  to two different sides. A switch  13  of a conventional pneumatic wrench  10  can be fixed only at a side of the pneumatic tool  10 , so that it is not suitable for all the users who are used to using their dominant hands. It can be learned from the above comparison, the present invention can be easily operated no matter the users who are right hand or left hand dominated. 
   In addition, the rotating direction switching device is designed for users who operate the switch by the thumb and the forefinger. As compared with a conventional device that users have to use the thumb to operate the switch, the present invention is more convenient and more comfortable. 
   To summarize, a rotating direction switching device for a pneumatic tool comprises an air inlet valve and a switch. The air inlet valve is driven to switch the rotating direction of the pneumatic tool by controlling the switch, thus simplifying the operation of switching between the clockwise mode and counterclockwise mode, and facilitating the operation by a single hand. Especially, no matter users who are right hand or the left hand dominated could easily operate the pneumatic tool. 
   While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.