Patent Publication Number: US-9844867-B2

Title: Cushion device for cylinder of pneumatic tool

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a cushion device, and more particularly to a cushion device for a cylinder of a pneumatic tool which reduces vibration. 
     DESCRIPTION OF THE PRIOR ART 
     A conventional pneumatic tool is driven by a high pressure air used as a power source. With reference to  FIG. 9 , the conventional pneumatic tool contains: a grip  10 , a valve unit  20 , a cylinder  30 , and a piston member  40 . The grip  10  includes an air inlet segment  101  connected with a high pressure air, an air passage  102  communicating with the air inlet segment  101 , a control switch (not shown) for controlling the high pressure air to flow into the air inlet segment  101 , and a cylindrical portion  103 . The cylindrical portion  103  has a chamber  104  defined therein and communicating with the air passage  102 . The valve unit  20  is mounted in the chamber  104  of the cylindrical portion  103 , and one end of the cylinder  30  is inserted into the chamber  104  of the cylindrical portion  103 , such that the cylinder  30  contacts with the valve unit  20 . The cylinder  30  includes a room  301  defined therein and a flowing channel  302  formed between a front end of the room  301  and the valve unit  20 , wherein the flowing channel  302  is in communication with the front end of the room  301  and the valve unit  20 , and the piston member  40  is accommodated and slides in the room  301  of the cylinder  30 . As turning on the control switch on the grip  10 , the high pressure air flows into the valve unit  20  in the chamber  104  of the cylindrical portion  103  from the air inlet segment  101  of the grip  10  via the air passage  102 , and the valve unit  20  controls the high pressure air to flow into the room  301  of the cylinder  30  and to push the piston member  40  toward a predetermined position, such that a tool head (not shown) is hit by the piston member  40 , and the tool head stops the piston member  40 , thereafter the valve unit  20  controls the high pressure air to flow into a front end of the room  301  of the cylinder  30  through the flowing channel  302 , such that the piston member  40  is pushed by the high pressure air to slide backward to impact the valve unit  20 , hence the piston member  40  is stopped by the valve unit  20 , thus moving the piston member  40  to operate the pneumatic tool. 
     However, when the piston member  40  slides backward to impact the valve unit  20 , a reaction force produces and passes toward user&#39;s hand, thus gripping the pneumatic tool difficultly and hurting the user&#39;s waist easily. 
     To overcome above-mentioned problem, a cylindrical cushion washer or a spring is fixed in the chamber of the cylindrical portion, such that the cylindrical cushion washer or the spring cushions impact force and absorbs vibration, when the piston member  40  slides backward to impact the valve unit  20 , thereby absorbing vibration and decreasing reaction force which passes toward the user&#39;s hand. Nevertheless, the cylindrical cushion washer and the spring cannot cushion the impact force evenly to reduce the reaction force. In addition, the cylindrical cushion washer and the spring cause elastic fatigue in repeated use, thus increasing use cost. 
     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 cushion device for a cylinder of a pneumatic tool in which a cushion washer is mounted in a chamber of a fitting sleeve of a body, and the cushion washer abuts against a closing face of the chamber of the fitting sleeve and a pressing face of an abutting portion of a cylinder, wherein the cushion washer includes at least one open segment arranged on at least one end thereof, the open segment has at least one air groove and contacts with the closing face, such that when the piston member moves backward to impact the valve unit, the cushion washer and the at least one air groove produce a compression like an airbag to absorb the vibration doubly and to reduce a reaction force of the cylinder which passes toward a user&#39;s hand, thus protecting the user&#39;s wrist. 
     Another objective of the present invention is to provide a cushion device for a cylinder of a pneumatic tool in which the cushion washer includes the at least one open segment arranged on the at least one end thereof, and the open segment has the at least one air groove, hence the cushion washer does not cause elastic fatigue in repeated use, thus reducing use cost. 
     To obtain above-mentioned objectives a cushion device for a cylinder of a pneumatic tool provided by the present invention contains: a body, a cylinder, a valve unit, and a piston member. 
     A cushion device is used for a cylinder of a pneumatic tool, and the pneumatic tool contains: a body, a cylinder, a valve unit, a piston member, and a cushion washer. 
     The body includes a grip and a fitting sleeve fitted with the grip, the fitting sleeve has a chamber defined therein, a closing face formed on a first end thereof, and an opening formed on a second end thereof. 
     The cylinder is slidably fitted in the chamber of the fitting sleeve, and a part of the cylinder extends out of the fitting sleeve from the opening of the chamber, the cylinder includes a room formed therein and an abutting portion adjacent to the closing face of the chamber of the fitting sleeve. 
     The valve unit is mounted between the room and the abutting portion of the cylinder. 
     The piston member is accommodated in the room of the cylinder and slides forward and backward along a movement axis. 
     The cushion washer is made of a flexible rubber and is mounted in the chamber of the fitting sleeve, and the cushion washer abuts against the closing face of the chamber of the fitting sleeve and the pressing face of the abutting portion of the cylinder. The cushion washer includes at least one open segment arranged on at least one end thereof, the at least one open segment has the at least one air groove, and each of the at least one air groove having a mouth parallel to the movement axis of the piston member, the at least one open segment contacts with the closing face or/and the pressing, such that the at least one air groove forms a flexible press space, thus producing double flexibility by using the cushion washer which is made of the flexible rubber and the at least one air groove which forms the flexible press space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing the assembly of a pneumatic tool according to a preferred embodiment of the present invention. 
         FIG. 2  is a perspective view showing the exploded components of the pneumatic tool according to the preferred embodiment of the present invention. 
         FIG. 3  is a cross sectional view showing the assembly of the pneumatic tool according to the preferred embodiment of the present invention. 
         FIG. 4  is a cross sectional view showing the operation of a piston member of the pneumatic tool according to the preferred embodiment of the present invention. 
         FIG. 5  is another cross sectional view showing the operation of the piston member of the pneumatic tool according to the preferred embodiment of the present invention. 
         FIG. 6  is also another cross sectional view showing the operation of the piston member of the pneumatic tool according to the preferred embodiment of the present invention. 
         FIG. 7  is a cross sectional view showing the assembly of a pneumatic tool according to another preferred embodiment of the present invention. 
         FIG. 8  is a cross sectional view showing the assembly of a pneumatic tool according to another preferred embodiment of the present invention. 
         FIG. 9  is a cross sectional view of a conventional pneumatic tool. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, a preferred embodiment in accordance with the present invention. 
     With reference to  FIGS. 1 to 3 , a cushion device for a cylinder of a pneumatic tool according to a preferred embodiment of the present invention, wherein the pneumatic tool comprises: a body  1 , a cylinder  2 , a valve unit  3 , a piston member  4 , and a cushion washer  5 , wherein the body  1  includes a grip  11  and a fitting sleeve  12  fitted with the grip  11 , the grip  11  has an air inlet segment  111 , an air passage  112  communicating with the air inlet segment  111 , and a control switch  113  for controlling air to flow into the air inlet segment  111 ; the fitting sleeve  12  has a chamber  120  defined therein, a closing face  121  formed on a first end thereof, an opening  122  formed on a second end thereof, and a bushing  123  fitted on an inner wall of the chamber  120  of the fitting sleeve  12 . The cylinder  2  is slidably fitted in the chamber  120  of the fitting sleeve  12 , and a part of the cylinder  2  extends out of the fitting sleeve  12  from the opening  122  of the chamber  120 . The cylinder  2  includes a room  20  formed therein, a limiting slot  21  defined on an outer side thereof to insert a defining element  124  of the fitting sleeve  12 , and an abutting portion  22  adjacent to the closing face  121  of the chamber  120  of the fitting sleeve  12 , wherein the abutting portion  22  has a pressing face  221  relative to the closing face  121  of the chamber  120  of the fitting sleeve  12 , and the pressing face  221  has a protective pad  222  fixed on a central position thereof. The valve unit  3  is mounted between the room  20  and the abutting portion  22  of the cylinder  2 , such that high pressure air flows toward the valve unit  3  via the air passage  112  of the grip  11 . The piston member  4  is accommodated in the room  20  of the cylinder  2  and slides forward and backward along a movement axis  41 . The cushion washer  5  is made of a flexible rubber and is mounted in the chamber  120  of the fitting sleeve  12 , and the cushion washer  5  abuts against the closing face  121  of the chamber  120  of the fitting sleeve  12  and the pressing face  221  of the abutting portion  22  of the cylinder  2 . The cushion washer  5  includes an open segment  51  arranged on a first end thereof and corresponding to the closing face  121 , the open segment  51  has at least one air groove  511  with a mouth parallel to the movement axis  41  of the piston member  4 , and the open segment  51  contacts with the closing face  121 , such that the at least one air groove  511  forms a flexible press space. The cushion washer  5  also includes a raised close segment  52  formed on a second end thereof and corresponding to the pressing face  221 , the close segment  52  contacts with the protective pad  222  of the pressing face  221  or the pressing face  221 , hence the cushion washer  5  (made of the flexible rubber) and the at least one air groove  511  (forming the flexible press space) produce double flexibility. 
     Referring to  FIG. 4 , after the control switch  113  on the grip  11  is turned on, the high pressure flows into a rear end of the room  20  of the cylinder  2  via the air passage  112  of the grip  11  and the valve unit  3  to push the piston member  4 , and the piston member  4  moves toward a front end of the room  20  to impact a tool head (not shown) and is stopped by the tool head. As shown in  FIGS. 5 and 6 , the high pressure air is controlled by the valve unit  3  to flow into the front end of the room  20  of the cylinder  2  to push the piston member  4 , hence the piston member  4  moves backward toward the rear end of the room  20  to impact the valve unit  3 , and the valve unit  3  drives the cylinder  2  to move backward, such that the cushion washer  5  and the at least one air groove  511  produce compression like airbag to absorb vibration doubly and to reduce reaction force which passes toward user&#39;s hand, thus pushing the piston member  4  forward and backward. 
     As illustrated in  FIG. 7 , in anther embodiment, the cushion washer  5  includes an open segment  51  arranged on a first end thereof and corresponding to an abutting portion  22  of a cylinder  2 , and the open segment  51  has at least one air groove  511  with a mouth parallel to a movement axis  41  of a piston member  4 , wherein the open segment  51  contacts with a pressing face  221 . The cushion washer  5  also includes a raised close segment  52  formed on a second end thereof and correspondingly abuts against to the closing face  121  of the chamber  120  of the fitting sleeve  12 , wherein the raised close segment  52  has a central position higher than its two sides. With reference to  FIG. 8 , in anther embodiment, the cushion washer  5  includes two open segments  51  arranged on a first end and a second end thereof, and each open segment  51  has at least one air groove  511  with a mouth parallel to a movement axis  41  of a piston member  4 . 
     Thereby, the cushion device of the present invention has advantages as follows: 
     1. The cushion washer  5  is mounted in the chamber  120  of the fitting sleeve  12  of the body  1 , and the cushion washer  5  abuts against the closing face  121  of the chamber  120  of the fitting sleeve  12  and the pressing face  221  of the abutting portion  22  of the cylinder  2 , wherein the cushion washer  5  includes at least one open segment  51  arranged on at least one end thereof, the open segment  51  has the at least one air groove  511 , and the at least one open segment  51  contacts with the closing face  121 , such that when the piston member  4  moves backward to impact the valve unit  3 , the cushion washer  5  and the at least one air groove  511  produce the compression like the airbag to absorb the vibration doubly and to reduce the reaction force of the cylinder  2  which passes toward the user&#39;s hand, thus protecting the user&#39;s wrist. 
     2. The cushion washer  5  includes the at least one open segment  51  arranged on the at least one end thereof, and the open segment  51  has the at least one air groove  511 , hence the cushion washer  5  does not cause elastic fatigue in repeated use, thus reducing use cost. 
     While various embodiments in accordance with the present invention have been shown and described, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.