Patent Publication Number: US-2013239759-A1

Title: Simple structure of locking pliers for releasing and opening handles and jaws through fast and direct pulling

Description:
CROSS-REFERNCE TO RELATED APPLICATIONS 
     The application is a continuation-in-part of co-pending U.S. patent application Ser. No. 13/216,257 filed on Aug. 24, 2011. 
    
    
     (a) TECHNICAL FIELD OF THE INVENTION 
     The present invention generally relates to a simple structure of locking pliers for releasing and opening handles and jaws through fast and direct pulling, and more particularly to a control structure comprising a movable joint pulling and pushing mechanism that is directly mounted to a tail end of a second handle of the pliers with a movable pulling bar of the pulling and pushing mechanism operable to directly push away an interconnection plate straddling between the first and second handles of the pliers, the movable pulling bar of the pulling and pushing mechanism being provided with a U-shape that has a side projecting to form a wing project in a portion thereof that is engageable with the tail end of the second handle so that the wing projection functions as a safety and protection device for human engineering purposes and the movable joint pulling and pushing mechanism is provided with a hand push-away function to protect a user&#39;s hand from clamping and injury 
     (b) DESCRIPTION OF THE PRIOR ART 
     Conventional locking pliers have jaws formed at front ends thereof and the opening of the jaws is controlled by a push-to-open operation of a movable pushing bar arranged inside a second handle of the pliers. However, since the movable pushing bar is concealed in a recess of the second handle of the pliers and forms a small gap with respect to the second handle of the pliers, whereby when a user attempts to operate and pull the concealed movable pushing bar, due to the small gap, a finger of the user, which is often thicker than the gap, cannot be readily put into the gap between the second handle of the pliers and the movable pushing bar to pull the movable pushing bar. This is a major drawback of the conventional locking pliers. 
     Thus, the industry of hand tool provides a solution for such a problem, which comprises an improvement made on bending angle of the second handle of pliers and the movable pushing bar for the purposes of forming an expanded gap therebetween to allow the insertion of a user&#39;s finger. However, such an arrangement is simply a solution solely for overcoming the gap size problem and does not take into consideration of other factors, such as reduction of cost. This is certainly a problem. 
     Further, the structure that is disclosed in the co-pending application and that disclosed in prior art references, such as U.S. Pat. No. 5,503,049 are such that a movable joint pulling and pushing mechanism is directly mounted to a tail end of a second handle of pliers and a movable pulling bar of the pulling and pushing mechanism is allowed to directly push away an interconnection plate straddling between the first and second handles of the pliers. However, in the structure of for example the above-mentioned US patent, the portion where the movable pulling bar of the pulling and pushing mechanism is engageable with the tail end of the second handle does not comply with the requirement in human engineering for safety and protection purposes. This is because the movable joint pulling and pushing mechanism is mounted to the tail end of the second handle of the pliers and movable pulling bar of the pulling and pushing mechanism may form a gap with respect to the tail end of the second handle in the operation thereof. Such a gap can be dangerous that the finger of the user may get clamped and injured when the bar is pulled. 
     SUMMARY OF THE INVENTION 
     Thus, in view of the problems and drawbacks of the conventional locking pliers and the pliers disclosed in the previously mentioned US patent, the present invention aims to provide a simple structure of locking pliers for releasing and opening handles and jaws through fast and direct pulling in order to improve the operation performance of the locking pliers on the essential basis of ensuring safe and comfortable operation of the pliers by a user so as to overcome the problems associated with opening of two jaws of the pliers and to make the opening fast and simple. 
     An objective of the present invention is to provide a simple structure of locking pliers for releasing and opening handles and jaws through fast and direct pulling, wherein a push-to-open operation carried out by a movable locking arm that straddles between first and second handles of the pliers is controlled by a movable joint pulling and pushing mechanism that is directly mounted to a tail end of the second handle of the pliers. The pulling and pushing mechanism comprises a movable pulling bar that forms, in a front end thereof, an arc recess that is positioned against a middle projection of the movable locking aim straddling between the first and second handles of the pliers, so that the second handle can be pushed away by a reaction force to open and thus causing opening of the jaws. The movable pulling bar of the pulling and pushing mechanism is provided with a U-shaped groove that has a side projecting to form a wing project in a portion thereof that is engageable with the tail end of the second handle so that the wing projection functions as a safety and protection device for human engineering purposes and the movable joint pulling and pushing mechanism is provided with a hand push-away function to protect a user&#39;s hand from clamping and injury. 
     Another objective of the present invention is to provide a control structure for fast pushing open two handles and jaws of locking pliers for fast opening, wherein a movable joint pulling and pushing mechanism is directly connected, through riveting, to a tail end of a second handle of the pliers, whereby the connection of the movable joint is realized through a two-sectioned riveting arrangement, so that parts are reduced to thereby realize both advantages of fast and easy operation and reduction of cost. 
     The foregoing objectives and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
     Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of locking pliers constructed in accordance with the present invention. 
         FIG. 2  is an exploded view of the locking pliers constructed in accordance with the present invention. 
         FIG. 3  is a plan view, partially broken, of the locking pliers constructed in accordance with the present invention. 
         FIG. 4  is a plan view, partially broken, illustrating an outward pulling operation of a movable pulling bar of a movable joint pulling and pushing mechanism mounted to a tail end of a second handle of the pliers according to the present invention; 
         FIG. 5  is a perspective view illustrating an opened condition of the pliers according to the present invention. 
         FIG. 6  is a plan view, partially broken, illustrating the opened condition of the pliers according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following descriptions are exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
     Referring to  FIGS. 1 ,  2 , and  3 , which are respectively a perspective view, an exploded view, and a plan view, partially broken, of locking pliers A constructed in accordance with the present invention, the locking pliers A comprises first and second handles  1 ,  2 , first and second jaws  3 ,  4  located at front ends, a tension spring  5 , a movable lever serving as a locking arm  6  that straddles between the first and second handles  1 ,  2  of the pliers, a movable joint pulling and pushing mechanism  7  that is riveted to a tail end of the second handle of the pliers, and an adjusting bolt  8  that is mounted to a cylindrical grip section  10  of the first handle  1 . The first handle  1  of the pliers A has a front end that is mounted by a flat-head rivet  100  and is fixed to the first jaw  3  through a stamped mounting spot to combine with the first jaw  3  as a one-piece combined structure and has a tail end that forms the cylindrical grip section  10  that has an inside circumference forming a threaded bore  11  extending therethrough. The threaded bore  11  threadingly engages the adjusting bolt  8 . 
     The second handle  2  of the pliers A has a front end that is fixed to the second jaw  4  by a flat-head rivet  200  to form a movable end structure. The second jaw  4  has an end to which the tension spring  5  is attached. The tension spring  5  has an opposite end that is attached to the first handle  1  to form a pulling state therebetween. 
     The movable locking arm  6  straddling between the first and second handles  1 ,  2  of the pliers has an end that is riveted by a flat-head rivet  300  to the second handle  2  to form a movable joint structure, while an opposite end of the movable locking arm  6  is received in a sideway-open slit  12  that is formed in a radial side surface of the first handle  1  of the pliers and is supported on a tip end of the adjusting bolt  8  that is threadingly received and retained in the threaded bore  11  of the cylindrical grip section  10  formed in the tail end of the first handle  1  of the pliers. 
     The second handle  2  of the pliers has a tail end that is riveted by a flat-head rivet  400  to the movable joint pulling and pushing mechanism  7 . The pulling and pushing mechanism  7  has a movable pulling bar  70  that has a front end forming an arc recess  71  that is positioned against a middle projection  60  of the movable locking arm  6  that straddles between the first and second handles  1 ,  2  of the pliers, whereby the front-end arc recess  71  of the movable pulling bar  70  of the pulling and pushing mechanism  7 , when pulled, undergoes a displacement that pushes away the middle projection  60  of the movable locking arm  6  that straddles between the first and second handles  1 ,  2  of the pliers to induce a reaction force that pushes away the second handle  2  to thereby release and open the second jaw  4  of the clamping mouth, as shown in  FIGS. 5 and 6 . 
     The movable pulling bar  70  of the pulling and pushing mechanism  7  is provided with a U-shaped groove  72 , which has a side projecting to form a wing projection  73 , in a portion thereof that is engageable with the tail end of the second handle  2 . The wing projection  73  is provided as a safety and protection device for human engineering purposes. 
     As such, with the first and second handles  1 ,  2  of the pliers being set in a clamped condition, in an attempt to release and open the first and second jaws  3 ,  4  of the front ends, the movable pulling bar  70  of the movable joint pulling and pushing mechanism  7  at the tail end of the second handle  2  of the pliers is directly pulled outwards, as shown in  FIG. 4 . Under this condition, the front-end arc recess  71  of the movable pulling bar  70  that is positioned against the middle projection of the movable locking arm  6  straddling between the first and second handles  1 ,  2  of the pliers is acted upon and pushed away by a reaction force of the movable pulling bar  70  to have the first and second handles  1 ,  2  opened and thus setting the first and second jaws  3 ,  4  at the front ends in an open condition, as shown in  FIGS. 5 and 6 , thereby realizing a fast and easy releasing and opening operation. At the same time, due to the wing projection  73  that is defined by the U-shaped groove  72  formed in the portion of the movable pulling bar  70  of the pulling and pushing mechanism  7  that is in engagement with the tail end of the second handle  2 , the U-shaped groove  72  is guided to mate and fit to the tail end of the second handle  2 . The wing projection  73  serves as a safety measure for pushing away the skin of the user&#39;s hand so as to protect the hand from clamping and injury. 
     Referring to  FIGS. 5 and 6 , which are respectively a perspective view and a plan view, partially broken, of the pliers according to the present invention in an opened condition, the first and second jaws  3 ,  4  of the front ends of the pliers A form a clamping mouth that is openable by being pushed by a pulling operation of the movable joint pulling and pushing mechanism  7  that is directly riveted to the tail end of the second handle  2  to form a two-sectioned arrangement so as to realize a fast-operated pull-to-open operation. 
     In summary, the simple structure of locking pliers for releasing handles and jaws through fast and direct pulling provides a function of fast opening the mouth opening size of the front-end jaws of the pliers. 
     It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
     While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.