Patent Publication Number: US-6662989-B1

Title: Device for adjusting single or auto shooting for staple guns

Description:
FIELD OF THE INVENTION 
     The present invention relates to a staple gun that has an adjusting member which lifts or lowers an activation plate connected with the trigger so as to perform single or auto shooting feature. 
     BACKGROUND OF THE INVENTION 
     A conventional staple gun is shown in FIGS. 1 and 2 and generally includes a body  10  with a valve  13  connected thereto which is activated by an activation plate  12  so as to eject a staple or a nail. The activation plate  12  is located behind the trigger  11  and a safety plate  14  extends through a hole  15  defined through the trigger  11  and contacts the activation plate  12 . The activation plate  12  includes a fork-like end and includes two protrusions  17  and a recess  16 , located between the two protrusions  17 . The safety plate  14  is first pushed against the object to be stapled and the pushes the activation plate  12  toward the valve  13 . When the trigger  11  is pulled, the body of the activation plate  12  touches the valve  13  to eject the staple. The push of the trigger  11  makes the activation plate  12  pivoted an angle so that the safety plate  14  no longer contacts the body of the activation plate,  12  and is located between the two protrusions  17 . Therefore, the activation plate  12  is not pushed by the safety plate  14  and no staple will be ejected even if the trigger  11  is pulled again. This single shooting feature does not meet the requirement of continuous shootings of the users and repeatedly release and pull the trigger consumes,;too much time and efforts. 
     The present invention intends to provide a device that can set the staple gun at single shooting or auto shooting status. 
     SUMMARY OF THE INVENTION 
     In accordance with one aspect of the present invention, there is provided a staple gun that has a trigger assembly which comprises a trigger with an activation plate received therein and an adjusting member connected to the trigger. A cam rod extends through the body of the staple gun and is engaged with an eccentric hole defined through the adjusting member such that the trigger and the activation plate are both lifted or lowered by rotating the adjusting member. The relative position between the activation plate, the valve and the safety plate of the staple gun can be adjusted so as to obtain different ways of shooting of the staples. 
    
    
     The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows the trigger assembly of a conventional staple gun; 
     FIG. 2 shows the activation plate of the conventional staple gun; 
     FIG. 3 shows the trigger assembly of the present invention; 
     FIG. 4 is an exploded view to show the trigger assembly of the present invention; 
     FIG. 5 shows the trigger and the activation plate are lowered; 
     FIG. 6 shows the activation plate is pushed by the safety plate; 
     FIG. 7 shows the trigger is pulled; 
     FIG. 8 shows the activation plate is not pushed by the safety plate after the trigger is pulled; 
     FIG. 9 shows the activation plate is lifted; 
     FIG. 10 shows the trigger is pulled; 
     FIG. 11 shows the trigger is kept being pulled and the activation plate is ready for the next push by the safety plate. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 3 and 4, the trigger assembly of the present invention comprises a trigger  30  having a chamber  31  defined between two side walls and a tube with a passage  32  is located at a first end of the trigger  30 . Two positioning holes  33  are defined through two the side walls of the trigger  30 . 
     An activation plate  40  has a contact portion  41  on a first end of the activation plate  40  and a through hole  42  is defined in a second end of the activation plate  40 . The activation plate  40  is received in the chamber  31  of the trigger  30  and a pin  34  extends through positioning holes  33  of the trigger  30  and the through hole  42  of the activation plate  40 . 
     An adjusting member  50  has a lever  51  extending from a periphery thereof and a lug  52  on an end of the adjusting member  50 . The adjusting member  50  is received in a hole  25  defined through the body  20  of the staple gun. Two positioning notches  26  are defined in an inner periphery of the hole  25 . The lug  52  is engaged with one of the two positioning notches  26 . An eccentric hole  53  is defined through the adjusting member  50  and a pin hole  54  is defined through the periphery of the adjusting member  50 . 
     A cam rod  60  extends from a board  62  and a spring  63  is mounted onto the eccentric section  61  of the cam rod  60 . The cam rod  60  extends through the hole  25  in the body  20  of the staple gun and the passage  32  of the trigger  30 . A distal end of the cam rod  60  extends through the eccentric hole  53  of the adjusting member  50 . A recess  64  is defined in the distal end of the cam rod  60  so that a pin  65  extends through the pin hole  54  in the adjusting member  50  and is engaged with the recess  64  in the cam rod  60 . 
     A safety plate  24  extends through a positioning member  23  which is connected to the body  20  of the staple gun and a distal end of the safety plate  24  located in the chamber  31  of the trigger  30 . A valve  21  is located beside the activation plate  40  and the trigger  30 , and a spring  22  is mounted on an activation pin of the valve  21 . 
     Referring to FIGS. 5 to  8 , when the adjusting member  50  is positioned at the single shooting position, the rotation of the eccentric section  61  of the cam rod  60  lowers the trigger  30  and the activation plate  40 . When the safety plate  24  is pushed, the distal end of the safety plate  24  pushes against the contact portion  41 . When the trigger  30  is pulled, the activation plate  40  is also moved to activate the activation pin  21  of the valve to shoot a staple. The contact portion  41  is lowered after the trigger  30  is pulled so that the safety plate  24  cannot push the contact portion  41  again. This allows the staple gun to be shoot one shot a time. 
     Referring to FIGS. 9 to  11 , the user may push the board  62  of the cam rod  60  to push the adjusting member  50  out from the hole  25  of the body  20  of the staple gun and the rotate the adjusting member  50  to let the lug  52  be engaged with the other positioning notch  26 . The trigger  30  and the activation plate  40  are then lifted and the body of the activation plate  40  is moved close to the activation pin  21  of the valve when the safety plate  24  is pushed against the object. 
     When pulling the trigger  30 , the staple is ejected and if the trigger is kept being pulled as shown in FIG. 10, the distal end of the safety plate  24  is still located at the position corresponding to the contact portion  41 . Therefore, when the user pushes the safety plate  24  again, the activation plate  40  is pushed by the safety plate  24  again to activate the valve so that the staple gun can shoot again. In other words, the user simply holds the trigger and pushes the safety plate  24  against the objects, the staple gun shoots without re-operating the trigger  30  again and again. 
     While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.