Patent Publication Number: US-6662691-B2

Title: Arresting device of pliers

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a pair of pliers, and more particularly to an arresting device which is mounted between two handles of the plies for checking motion of the two handles. 
     BACKGROUND OF THE INVENTION 
     As shown in FIGS. 11 and 12, a pair of pliers  8  of the prior art comprises two handles  81  and  82 , between which an arresting device  9  and a recovery spring  83  are mounted. The arresting device  9  comprises a sleeve  91  and a rod  92  fitted into the sleeve  91 . The sleeve  91  is pivotally fastened at one end with the first handle  81 , whereas the rod  92  is pivotally fastened at one end with the second handle  82  such that other end of the rod  92  is fitted into other end of the sleeve  91  in conjunction with a spring  94  which is fitted over the other end of the rod  92 . The other end of the sleeve  91  is provided with a projection  911  extending therefrom for pivoting one end of a retaining member  93 . The retaining member  93  has a hole  931  with a hole diameter slightly greater than the outer diameter of the rod  93 . The retaining member  93  is provided with a control lever  932  extending therefrom. The spring  94  is located between the other end of the sleeve  91  and the retaining member  93 . The retaining member  93  is urged by the spring  94  to tilt such that the hole  931  of the retaining member  93  is fitted slantingly over the rod  92 . As the rod  92  is pushed into the sleeve  91 , the retaining member  93  is pushed away to enable the rod  92  to enter the sleeve  91 . In the meantime, the rod  92  is located by the retaining member  93  to prevent the rod  92  from being drawn out of the sleeve  91 . As a result, the two handles  81  and  82  of the pliers  8  can not be moved away from each other, so as to allow two jaws of the pliers  8  to remain in the state of holding a workpiece. The two handles  81  and  82  are set free by pressing the control lever  932  of the retaining member  93  to bring about the disengagement of the retaining member  93  with the rod  92 . The two handles  81  and  82  are thus forced by the spring  83  to move away from each other. 
     Such a prior art arresting device  9  as described above is limited in function in that it is capable of locating the handles of the pliers  8  in a unidirectional manner. As a result, the prior art pliers  8  can not be used to work on a variety of workpieces. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a pair of pliers with an arresting device which is free of the deficiency of the prior art arresting device described above. 
     In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by an arresting device which is disposed between two handles of a pair of pliers and is formed of a sleeve and a rod. The sleeve is pivotally fastened at one end with a first handle of the pliers, whereas the rod is pivotally fastened at one end with a second handle of the pliers. The sleeve is provided at other end with a receiving cell and a retaining piece which is disposed in the receiving cell such that one end of the retaining piece prsses against a projection of the receiving cell. The retaining piece has a movable end and a through hole with a hole diameter greater than an outer diameter of the rod. A spring is disposed between the retaining piece and one side wall of the receiving cell such that one end of the spring urged the retaining piece to enable the movable end of the retaining piece to sway so as to cause the through hole of the retaining piece to retain slantingly the rod. The receiving cell is provided with a pin corresponding in location to the movable end of the retaining piece. The pin is turned to cause the retaining piece to release the rod, thereby enabling the rod to move in two directions. The pin is provided at one end with a recess, and at other end with a control lever. As the control lever is turned such that the recess of the pin is corresponding in location to the retaining piece, the movable end of the retaining piece is in the free state, thereby enabling the retaining piece to be pushed by the spring force of the spring to retain the rod in such a manner that the retaining piece restricts unidirectionally the movement direction of the rod. 
     The features and the advantages of the present invention will be more readily understood upon a thoughtful deliberation of the following detailed description of two preferred embodiments of the present invention with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 shows a perspective view of a first preferred embodiment of the present invention. 
     FIG. 2 shows an exploded view of the first preferred embodiment of the present invention. 
     FIG. 3 shows a longitudinal sectional view of the first preferred embodiment of the present invention in combination. 
     FIG. 4 shows a longitudinal sectional view of the first preferred embodiment of the present invention in action. 
     FIG. 5 shows another longitudinal sectional view of the first preferred embodiment of the present invention in action. 
     FIG. 6 shows another longitudinal sectional view of the first preferred embodiment of the present invention in action. 
     FIG. 7 shows a schematic view of the first preferred embodiment of the present invention at work. 
     FIG. 8 shows a longitudinal sectional view of a second preferred embodiment of the present invention. 
     FIG. 9 shows an enlarged sectional view of the second preferred embodiment of the present invention. 
     FIG. 10 shows a schematic view of the second preferred embodiment of the present invention at work. 
     FIG. 11 shows a perspective view of an arresting device of the prior art. 
     FIG. 12 shows an enlarged sectional view of the prior art arresting device as shown in FIG.  11 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     As shown in FIGS. 1-7, an arresting device  2  embodied in the present invention is mounted between a first handle  11  and a second handle  12  of a pair of pliers  1 . The arresting device  2  comprises a sleeve  21  and a rod  22 . The sleeve  21  is pivotally fastened at one end with the first handle  11 , while the rod  22  is pivotally fastened at one end with the second handle  12 . The sleeve  21  has an axial hole  211  which is dimensioned to receive the rod  22  via a receiving cell  24  located at other end of the sleeve  21 . The rod  22  is provided at other end with a receiving hole  220 . Located between the bottom  212  of the axial hole  211  and the receiving hole  220  of the rod  22  is a first spring  23 , which urges the rod  22  to jut out of the sleeve  21 . The rod  22  is further provided at other end with a small diametrical segment  221  and a retaining ring  222  fitted over the small diametrical segment  221 . The retaining ring  222  is slightly greater in outer diameter than the rod  22 . 
     The receiving cell  24  of the sleeve  21  is provided with a cover  28 , and a retaining piece  25  which is located in the receiving cell  24  such that one end of the retaining piece  25  presses against a projection  241  of the receiving cell  24 , and that the retaining piece  25  is contiguous to other end of the sleeve  21 . The retaining piece  25  has a movable end  251  which is located at other end of the retaining piece  25 . The retaining piece  25  is provided with a through hole  252  greater in diameter than the rod  22 . Located between the retaining piece  25  and one side wall  242  of the receiving cell  24  is a second spring  26 , which urges the retaining piece  25  such that the movable end  251  of the retaining piece  25  sways in the direction toward the rod  22 , thereby enabling the through hole  252  to retain slantingly the rod  22  which is thus capable of moving inwards only. 
     The receiving cell  24  is provided with a pin  27  corresponding in location to the movable end  251  of the retaining piece  25 . The pin  27  is capable of pushing the retaining piece  25  away from the rod  22 , so as to enable the rod  22  to move freely in two directions. The pin  27  is movably disposed in the receiving cell  24  such that a control lever  272  of the pin  27  is jutted out of the receiving cell  24 . The pin  27  is provided with a recess  271  corresponding in location to the retaining piece  25 . When the pin  27  is so turned that the recess  271  is opposite to the retaining piece  25 , the movable end  251  of the retaining piece  25  is in the free state. As the retaining piece  25  is pushed by the spring force of the second spring  26 , the through hole  252  of the retaining piece  25  retains slantingly the rod  22  such that the rod  22  can move inwards only. 
     When the pliers  1  are used the hold a workpiece, the pin  27  is first turned such that the recess  271  of the pin  27  is corresponding in location to the retaining piece  25 , thereby enabling the movable end  251  of the retaining piece  25  to be in the free state, as shown in FIG.  4 . In the meantime, the retaining piece  25  is urged by the second spring  26  to sway such that the rod  22  is retained by the through hole  252  of the retaining piece  25 . When the two handles  11  and  12  are held firmly, the rod  22  is pushed to slide into the sleeve  21 . When the rod  22  slides, the movable end  251  of the retaining piece  25  is actuated to move backwards. As a result, the rod  22  is no longer retained by the through hole  252  of the retaining piece  25 , as shown in FIG.  5 . The rod  22  can be moved into the axial hole  211  of the sleeve  21 . When the two handles  11  and  12  are no longer held firmly, the retaining piece  25  is urged by the second spring  26  to move back to the state as shown in FIG. 4, so as to locate the rod  22 . As a result, the two handles  11  and  12  are located. 
     The pliers  1  can be freely set to facilitate the holding of any workpiece by turning the control lever  272  of the pin  27 , thereby causing the pin  27  to push the movable end  251  of the retaining piece  25  so as to prevent the rod  22  from being retained by the through hole  252  of the retaining piece  25 , as shown in FIG.  6 . The rod  22  is thus in the free state to enable the two handles  11  and  12  of the pliers  1  to move toward or away from each other to hold a workpiece, as shown in FIG.  7 . The first spring  23  is at work to urge the rod  22  and the sleeve  21  so as to cause the two handles  11  and  12  to return to their original positions. As a result, the pliers  1  of the present invention is devoid of a recovery spring which is provided in the prior art pliers. The retaining ring  222  of the rod  22  serves to prevent the rod  22  from slipping out of the sleeve  21  by being retained in the through hole  252  of the retaining piece  25  at the time when the rod  22  is in motion. 
     The arresting device  2  is characterized by the movable end  251  of the retaining piece  25 , and the pin  27  which is pivoted to the receiving cell  24  to push away the retaining piece  25  so that the rod  22  is not retained by the retaining piece  25 . When the pin  27  is so turned that the recess  271  of the pin  27  is corresponding in location to the retaining piece  25 , the movable end  251  of the retaining piece  25  is in the free state, thereby enabling the second spring  26  to urge the retaining piece  25  to retain the rod  22 . The present invention is provided with the first spring  23 , which is located between the sleeve  21  and the rod  22  to enable the two handles  11  and  12  of the pliers  1  to return to their original positions. 
     As shown in FIGS. 8-10, an arresting device  4  of the second preferred embodiment of the present invention is mounted between a first handle  31  and a second handle  32  of a pair of pliers  3 . The arresting device  4  comprises a retaining piece  45  which is disposed in a receiving cell  44 , and a spring  46  which is disposed between the retaining piece  45  and a side wall  442  of the receiving cell  44 . When the movable end  451  of the retaining piece  45  is in the free state, the retaining piece  45  is in the free state, the retaining piece  45  is urged by the spring  46  to retain the rod  42 , which is thus capable of moving outward only. 
     When the pliers  3  are used to hold a workpiece, the pin  47  is turned to push away the retaining piece  45  from the rod  42 , as shown in FIG.  9 . The rod  42  is thus allowed to move in two directions. When the two handles  31  and  32  are gripped securely, the rod  42  is actuated to move into the sleeve  41  so as to enable two jaws  33  and  34  of the pliers  3  to hold an object “B”, as shown in FIG.  10 . As the pin  47  is turned such that the recess  471  of the pin  47  is opposite to the retaining piece  45 , and that the movable end  451  of the retaining piece  45  is in the free state. The retaining piece  45  is urged by the second spring  46  such that the rod  42  is slantingly retained by the through hole  452 . As a result, the rod  42  can not be moved inwards, thereby locating the two handles  31  and  32  to hold the object “B”. The object “B” can be let go by turning the pin  47  to push away the retaining piece  45 , so as to enable the rod  42  to move in two directions. As a result, the two handles  31  and  32  can be moved away from each other to enable the jaws  33  and  34  to release the object “B”. 
     The embodiments of the present invention described above are to be regarded in all respects as being merely illustrative and nonrestrictive. Accordingly, the present invention may be embodied in other specific forms without deviating from the spirit thereof. The present invention is therefore to be limited only by the scopes of the following claims.