Patent Publication Number: US-7213733-B1

Title: Nail gun switch mechanism for switching dual actuation modes

Description:
BACKGROUND 
   The present invention relates to a nail gun switch mechanism, and particularly to a nail gun switch mechanism for switching the nail gun operation in a sequential actuation mode, a contact actuation mode, or a holding actuation mode. 
   Actuating nails for a pneumatic nail gun generally can be divided into two kinds, one is the sequential actuation mode (or the restrictive mode) and the other is the contact actuation mode. 
   The sequential actuation mode means the operator firstly should set a safety slidable bar or a hitting base on the safety slidable bar contacting on a workpiece to push an upward movement of a trigger lever, and then press a trigger to bring the trigger lever to actuate a trigger valve. In this mode, if the operator wants to actuate again, he should release the trigger first, and then repeat the processes of pressing the trigger. If the operator disobeys the operating sequence, i.e. first pressing the trigger and then pressing the safety slidable bar or the hitting base of the safety slidable bar, the trigger lever in the trigger can not be brought to actuate the trigger valve and nails in the nail gun is held to be driven. Thus, no dangerous accidental shot happens when the safety slidable bar or the hitting base of the safety slidable bar is wrongly touched by somebody. 
   The contact actuation mode means the operator should first continuously press the trigger, and then move the safety slidable bar or the hitting base of the safety slidable bar on the workpiece to perform continuously contact hitting, which makes the trigger lever brought to upwardly move and actuates the trigger valve to continuous shot. In addition, the contact actuation mode also allows the operator first sets the safety slidable bar or the hitting base of the safety slidable bar on the workpiece to bring the trigger lever to upwardly move, and then individually or continuously presses the trigger to respectively actuate single or multiple nails for fastening the workpiece. 
   These two actuation modes are both used in a nail gun by utilizing a switch mechanism to realize switching of the sequential actuation mode and the contact actuation mode. As shown in U.S. Pub. No. 20050184120, a rotating rod is included in a contact safety assembly which is constructed to slide toward/away from a driver housing. The rotating rod includes a first shoulder or ledge and a second shoulder which is off-set from the first shoulder. The rod may be rotated in order to orientate the selected shoulder, to function as a step for a pivoting trigger assembly, which is constructed to contact a pneumatic valve, to initiate a fastening event in which a fastener is driven into a workpiece. The configuration of the rotating rod permits for selection between a contact actuation mode and a sequential actuation mode. However the mechanism can not permit a holding actuation mode, which makes the nail gun is easily to be wrongly actuated when the nail gun is set on something or is brought by somebody. Thus, accidentally dangerous shot easily happens. 
   BRIEF SUMMARY 
   An example nail gun switch mechanism of the present invention has a trigger valve bar received in a trigger of the nail gun; a trigger lever pivotally disposed on the trigger; a safety slidable bar pivotally disposed on a gun body; a longitudinal guiding hole formed at a peripheral side of the gun body between the safety slidable bar and the trigger; a shaft slidably received in the guiding hole; a switch bar arranged on the shaft, which the switch bar can bring the shaft to rotate in the longitudinally guiding hole; and a hitting base of the safety slidable bar extending out from an hitting mouth formed at a bottom portion of the gun body. The shaft has a bias pole disposed at a top portion thereof, and the bias pole can synchronously rotate with the shaft and can be reposited by adjusting the switch bar. The trigger lever has a shorter end portion formed at an end thereof, which can be pushed by the bias pole to actuate the trigger valve bar when the sequential actuation operates. In addition, a longer end portion is formed at the end of the trigger lever, which can be pushed by the bias pole to actuate the trigger valve bar when the contact actuation operates, and an opening is formed at the end, which does not receive the push of the bias pole. 
   The nail gun switch mechanism utilizes the trigger lever and bias pole to improve the safety ratio, whatever the nail gun is placed, taken, or in use. In addition, the nail gun switch mechanism is convenient in operation and has a lower manufacturing cost. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features and advantages of the various embodiments disclosed herein will be better understood with respect to the following description and drawings, in which like numbers refer to like parts throughout, and in which: 
       FIG. 1  is a schematic, partially cross-sectional view of a nail gun switch mechanism according to a first embodiment of the present invention; 
       FIG. 2  is a partially enlarged view of the nail gun switch mechanism; 
       FIG. 3  is a cross-sectional view of the nail gun switch mechanism of  FIG. 2 ; 
       FIG. 4  is a front view of a trigger lever of the nail gun switch mechanism of  FIG. 1 ; 
       FIG. 5  is a top view of a base of the nail gun switch mechanism of  FIG. 2 ; 
       FIG. 6  is a schematic view disclosing an operation of a sequential actuation mode; 
       FIG. 7  is a schematic view disclosing another operation of the sequential actuation mode; 
       FIG. 8  is a schematic view disclosing a further another operation of the sequential actuation mode; 
       FIG. 9  is a schematic view disclosing further another operation of the sequential actuation mode; 
       FIG. 10  is another top view of the base of the nail gun switch mechanism of  FIG. 2 ; 
       FIG. 11  is a schematic view disclosing an operation of a contact actuation mode; 
       FIG. 12  is a schematic view disclosing an another operation of the contact actuation mode; 
       FIG. 13  is a schematic view disclosing further another operation of the contact actuation mode; 
       FIG. 14  is a schematic view disclosing further another operation of the contact actuation mode; 
       FIG. 15  is a further another top view of the base of the nail gun switch mechanism of  FIG. 2 ; 
       FIG. 16  is a schematic view disclosing an operation of a holding actuation mode; 
       FIG. 17  is a schematic view disclosing another operation of the holding actuation mode; 
       FIGS. 18 to 20  are front views of a trigger lever of a nail gun switch mechanism according to an alternative embodiment; 
       FIGS. 21 to 23  are front views of a trigger lever of a nail gun switch mechanism according to another alternative embodiment; and 
       FIG. 24  is a cross-sectional view of a nail gun switch mechanism of the second embodiment of the present invention. 
   

   DETAILED DESCRIPTION 
     FIG. 1  discloses a nail gun switch mechanism according to a first embodiment of the present invention. The nail gun switch mechanism has a trigger  2  and a safety slidable bar  3  pivotally disposed on a gun body  1 . The nail gun switch mechanism further has a trigger valve bar  21  received in the trigger  2 , a trigger lever  4  pivotally disposed thereon, a longitudinally guiding hole  51  formed at a peripheral side of the gun body  1  between the safety slidable bar  3  and the trigger  2 , a shaft  6  slidably received in the longitudinally guiding hole  51  (as shown in  FIGS. 2 to 3 ). 
   The trigger lever  4  has a pivot base  43  (as shown in  FIG. 4 ) pivotally disposed on the trigger  2 . When the trigger lever  4  is pushed or is brought to upwardly move (as shown in  FIG. 7 ), an intermediate portion of the trigger lever  4  can push the trigger valve bar  21 . 
   The safety slidable bar  3  has a bend shape (as shown in  FIG. 1 ). One end of the safety slidable bar  3  connects with the shaft  6  (referring to  FIGS. 2 and 3 ) through a hitting depth adjuster  7 ; another end of the safety slidable bar  3  connects with a hitting base  30  and extends out from an hitting mouth  10  formed at a bottom portion of the gun body  1 . The nail gun switch mechanism further has a switch bar  81  arranged on the shaft  6 , which the switch bar  81  can bring the shaft  6  to rotate in the longitudinally guiding hole  51 . 
   The shaft  6  has a bias pole  61  (as shown in  FIGS. 1 to 3 ) disposed at a top portion thereof, and the bias pole  61  can synchronously rotate with the shaft  6  and can be reposited by the adjustment of the switch bar  81 . 
   The trigger lever  4  (as shown in  FIG. 4 ) has a shorter end portion  41  formed at an end, which can be pushed by the bias pole  61  when the nail gun operates in a sequential actuation mode (as shown in  FIGS. 5 and 6 ). 
   The trigger lever  4  (as shown in  FIG. 4 ) further has a longer end portion  42  formed at the end, which can be pushed by the bias pole  61  when the nail gun operates in a contact actuation mode (as shown in  FIGS. 10 and 11 ). 
   The trigger lever  4  further has an opening  40  formed at the end, which does not receive the push of the bias pole  61  (as shown in  FIGS. 15 and 16 ). 
   In addition, the nail gun switch mechanism further has a base  5  formed on an outer peripheral side of the gun body  1  between the trigger  2  and the safety slidable bar  3 . The base  5  has a top base  52 , a bottom base  53  and a single-side longitudinal opening groove  54  between the top base  52  and the bottom base  53 . The top base  52  can have a plurality of longitudinal notches  55  formed at a bottom thereof. 
   The guiding hole  51  has a circular shape formed between the top base  52  and the bottom base  53  (as shown in  FIGS. 2 and 3 ), which passes through a top end and a bottom end of the base  5 . 
   The shaft  6  is a column, which has at least one longitudinal fillister  62  (as shown in  FIG. 2 ) formed at a peripheral sidewall of the shaft  6 . The longitudinal fillister  62  can be made like a slideway for nesting a switch button  8 . The switch button  8  has a through hole  82  formed in a central portion thereof and at least one longitudinal protruding rib  83  formed at an inner peripheral surface of the switch button  8  thereon, where the at least one longitudinal protruding rib  83  can be slidably received in the longitudinal fillister  62  of the shaft  6 . 
   The switch bar  81  can be formed on the switch button  8  (as shown in  FIGS. 2 and 3 ), and the switch button  8  is a ring-shaped column and is received in the single-side longitudinal opening groove  54  of the base  5 . In addition, the switch button  8  can further has a protrusion  85  formed at a shoulder portion thereof, in which the protrusion  85  matches with the plurality of longitudinal notches  55  for locating the switch button  8  at corresponding positions of the contact actuation mode, sequential actuation mode or holding actuation mode. 
   A spring  9  (as shown in  FIG. 2 ) is provided between the shaft  6  and the switch button  8 . The shaft  6  has a flange  63  (as shown in  FIG. 3 ) at a peripheral outer surface for supporting the spring  9 . Thus, the shaft  6  can move between the switch button  8  and the guiding hole  51  by the elastic deformation of the spring  9 . In addition, the shaft  6  has a bottom hole  64  formed at a bottom center thereof. 
   The hitting depth adjuster  7  has a tooth bolt  73 , a knob  71  and a stopper ring  72  (as shown in  FIGS. 1 to 3 ). The tooth bolt  73  is formed on a top portion of the safety slidable bar  3 , which is received in the bottom hole  64  of the shaft  6  and nested in the shaft  6  by the thrust of the spring  9 . 
   The knob  71  is in a shape of screw cap, which has a slideproof peripheral surface for convenience of manual operation. The knob  71  has a concave circular groove  711  nesting on a bottom portion of the shaft  6 , a tooth hole  712  nesting on the tooth bolt  73 , a plurality of block grooves  713  formed on a top portion of the knob  71 . 
   The stopper ring  72  has a ring shape with a vacant circular center, which is nested on a bottom portion of the flange  63  of the shaft  6  (as shown in  FIG. 2 ). The stopper ring  72  has a plurality of protrusions  721  corresponding to the notches  713  of the knob  71 , in which the protrusions  721  can slip between the notches  713  and be located in the notch  713 . In addition, the stopper ring  72  has two protruding blocks  722  respectively formed at two sides thereof, in which the two protruding blocks  722  are slidably disposed at a longitudinal guiding groove  56  formed at two sides of a bottom portion of the base  5 , for preventing the stopper ring  72  from rotating (as shown in  FIG. 3 ). The operator can adjust position of the knob  71  on the tooth  73  for controlling a distance between the safety slidable bar  3  and the hitting base  30 , which can realize the hitting depth adjustment. 
   The shorter end portion  41  of the trigger lever  4  is disposed at one side of the longer end portion  42  (as shown in  FIG. 4 ) of the trigger lever  4 , and the opening  40  is defined between the shorter end portion  41  and the longer end portion  42 . 
   According to the aforementioned structure, the operation of the present invention is described as follows. 
   To set up the pneumatic nail gun in a sequential actuation mode, the operator can adjust the switch bar  81  (as shown in  FIG. 5 ) of the switching button  8  to one side of the base  5  for rotating the bias bar  61  under the shorter end portion  41  of the trigger lever  4 . At this moment, the operator must push the hitting base  30  at the bottom portion of the safety slidable bar  3  on a workpiece, which makes the hitting base  30  and the safety slidable bar  3  to move upwardly (as shown in  FIG. 6 ), and bring the bias pole  61  to move upward and push the shorter end portion  41  of the trigger lever  4  through the hitting depth adjuster  7  and the shaft  6 . After that, the operator can press the trigger  2  (as shown in  FIG. 7 ) to bring an upward movement of the pivot base  43  of the trigger lever  4 , which brings the trigger lever  4  to move upwardly to push the trigger valve bar  21 , and actuate the pneumatic nail gun sequentially shoot. 
   In addition, if the operator wrongly operates, i.e. the operator firstly presses the trigger  2  (as shown in  FIG. 8 ), and then pushes the hitting base  30  or the safety slidable bar  3  to bring the shaft  6  and the bias bar  61  to upwardly move (as shown in  FIG. 9 ), no actuating event happens, because the pressed trigger  2  brings the trigger lever  4  to upwardly move, which makes the shorter end portion  41  of the trigger lever  4  away from a position that the bias bar  61  can reach. Thus, the trigger valve bar  21  can not be actuated. Therefore, a safety sequential actuation mode is realized. 
   To set up the pneumatic nail gun in a contact actuation mode, the operator can adjust the switch bar  81  (as shown in  FIG. 10 ) of the switching button  8  to another side of the base  5  for rotating the bias bar  61  under the longer end portion  42  of the trigger lever  4 . At this moment, the operator can firstly press the trigger  2  to bring the pivot base  43  of the trigger lever  4  to upwardly move (as shown in  FIG. 11 ), and then push the hitting base  30  at the bottom portion of the safety slidable bar  3  on a workpiece, which makes the hitting base  30  and the safety slidable bar  3  to move upwardly, and bring the bias pole  61  (as shown in  FIG. 12 ) to move upwardly to push the longer end portion  42  of the trigger lever  4  through the hitting depth adjuster  7  and the shaft  6 . The upward movement of the longer end portion  42  of the trigger lever  4  drives the trigger lever  4  to move upwardly to push the trigger valve bar  21 , and actuates the pneumatic nail gun to work in the contact actuation mode. In this operation mode, the operator can press the trigger  2  continuously, or continuously repeat the actions of releasing and pressing the hitting base  30  to continuously push the longer end portion  42  of the trigger lever  4  through the bias bar  61 . Thus, a continuous contact actuation mode can be attained. 
   In addition, in the contact actuation mode, the operator also can firstly press the hitting base  30  on the workpiece to bring the safety slidable bar  3  to move upwardly and bring the bias pole  61  (as shown in  FIG. 13 ) to move upwardly to push the longer end portion  42  of the trigger lever  4  through the hitting depth adjuster  7  and the shaft  6 . And then, the operator can individually or continuously press the trigger  2  (as shown in  FIG. 14 ) to conveniently actuate a single or a plurality of nails on the workpiece. 
   To set up the pneumatic nail gun in a holding actuation mode, the operator can adjust the switch bar  81  (as shown in  FIG. 15 ) of the switching button  8  ahead a center portion of the base  5  for rotating the bias pole  61  in the opening  40  of the trigger lever  4 . If the operator wrongly operates the safety slidable bar  3  or the hitting base  30  to actuate the shaft  6  and the bias bar  61  to move upwardly (as shown in  FIG. 16 ), the bias bar  61  passes through the opening  40  of the trigger lever  4 . Thus, the trigger lever  4  can not be pushed by the upward bias bar  61  and keeps immovable. In addition, if the operator wrongly operates, i.e. the operator firstly presses the trigger  2  (as shown in  FIG. 17 ), and then pushes the hitting base  30  or the safety slidable bar  3  to bring the shaft  6  and the bias bar  61  to upwardly move, also no danger actuating event happens because the upward bias bar  61  also can not touch the trigger lever  4 . Therefore, the trigger valve bar  21  can not be wrongly actuated, and the safety ratio of the nail gun switch mechanism is improved, whatever the nail gun is placed, taken, or in use. In addition, the nail gun switch mechanism is convenient in operation and has a lower manufacturing cost. 
   In a variation modification, a shorter end portion  41   a  can also be defined at a tail end of a longer end portion  42   a  (as shown in  FIG. 18 ); an opening  40   a  is a cutout of the trigger lever  4   a  defined at a side of the longer end portion  42   a , which can let the bias bar  61  to reposit under the shorter end portion  41   a , the longer end portion  42   a  or the opening  40   a  (as shown in  FIGS. 18 to 20 ). In another variation modification, an opening  40   b  is a cutout at a corner of a trigger lever  4   b  beside a longer end portion  42   b , and a shorter end portion  41   b  is formed between the longer end portion  42   b  and the opening  40   b , which can let the bias bar  61  to reposit under the shorter end portion  41   b , the longer end portion  42   b , or the opening  40   b  (as shown in  FIGS. 21 to 23 ). 
   In another embodiment of the present invention, a nail gun switch mechanism can get rid of the hitting depth adjuster  7 , which can utilize a screw  31  to fix the safety slidable bar  3  on the bottom portion of the shaft  6  (as shown in  FIG. 24 ). The nail gun switch mechanism can also realize the switching operation between the sequential actuation mode, the contact actuation mode and the holding actuation mode. 
   The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including configurations ways of the recessed portions and materials and/or designs of the attaching structures. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.