Patent Publication Number: US-11383357-B2

Title: Universal pliers

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of Taiwanese Patent Application No. 108114016, filed on Apr. 22, 2019. 
     FIELD 
     The disclosure relates to a hand held clamp tool, more particularly, to a pair of universal pliers. 
     BACKGROUND 
     Referring to  FIG. 1 , a pair of conventional universal pliers  12  with a quick release mechanism includes a first jaw  121 , an upper handle  122  connected to the first jaw  121 , a second jaw  123  disposed opposite to the first jaw  121 , a front handle  124  pivotally coupled to the second jaw  123 , a rear handle  125  pivotally coupled to the front handle  124 , a linkage mechanism  126  for actuating the front handle  124  to rotate and in turn drive the second jaw  123  to a position for releasing or clamping an object  13 , and a locking mechanism  127  for retaining a rigid connection between the front handle  124  and the rear handle  125 . The locked mechanism  127  includes an arcuate slot  1271  formed in the front handle  124 , and a release button  1272  disposed with respect to the front handle  124  for operatively associating with a movable pin  1273  engaged in the arcuate slot  1271 . The release button  1272  also includes an elongate slot  1274  for mounting the rear handle  125 . While the object  13  is clamped by the universal pliers  12 , the movable pin  1273  is restricted from moving by the arcuate slot  1271  so that the rear handle  125  is prevented from rotating relative to the front handle  124 , thereby maintaining the universal pliers  12  in a position for firmly clamping the object  13 . As shown in  FIG. 2 , upon pressing the release button  1272 , the moveable pin  1273  is driven along the arcuate slot  1271  to a releasing position where the rear handle  125  is allowed to rotate relative to the front handle  124  and in turn drives the second jaw  123  to rotate counter-clockwise (as indicated by the arrow shown in dotted lines) to release the gripped object  13 . This pair of conventional pliers  12  thus allow single-handed manipulation. 
     SUMMARY 
     The object of the disclosure is to provide a pair of universal pliers of a newly devised structure that is more convenient to use. 
     According to the disclosure, the universal pliers comprise a fixed structure, a movable structure, and a quick release mechanism. 
     The fixed structure extends in a front-rear direction, and includes a fixed jaw plate and a fixed handle plate that extends rearward from the fixed jaw plate. The fixed jaw plate has a fixed clamping portion. The movable structure is movably connected to the fixed structure, and includes a movable jaw plate, a front movable handle plate, and a rear movable handle plate. 
     The movable jaw plate has a movable clamping portion opposite to the fixed clamping portion and forming a clamping hole that is in conjunction with the fixed clamping portion. The front movable handle plate is pivotally coupled to and extends rearward from the movable jaw plate. The front movable handle plate has a first guide slot at a rear end thereof. The first guide slot defines a locked segment and a releasing segment at opposite ends thereof, and an intermediate segment between the locked segment and the releasing segment. The rear movable handle plate has a pivoting end pivotally coupled to the front movable handle plate, a grip end opposite to and disposed at a rear side of the pivoting end, and a second guide slot located between the pivoting end and the grip end. The movable structure is movable relative to the fixed structure between a retaining position where the movable clamping portion is adjacent to the fixed clamping portion, and a releasing position where the movable clamping portion is spaced far from the fixed clamping portion. 
     The quick release mechanism includes a trigger and a resilient locking subunit. The trigger is pivotally coupled to and accessibly protrudes from the front movable handle plate. The resilient locking subunit is operatively connected to the trigger and the movable structure, and includes a movable pin, a pulling member, and a resilient member. The movable pin is inserted through and is slidable along the first guide slot and the second guide slot. The pulling member is connected between the movable pin and the trigger, such that the pivot action of the trigger drives the resilient locking subunit to switch between a locked state where the movable pin is located at the locked segment of the first guide slot and where the rear movable handle plate is not permitted to pivot relative to the front movable handle plate, and a non-locked state where the movable pin is located at the intermediate segment of the first guide slot and where the rear movable handle plate is permitted to pivot relative to the front movable handle. The resilient member is connected between the movable pin and the rear movable handle plate to resiliently bias the resilient locking subunit towards the locked state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment with reference to the accompanying drawings, of which: 
         FIG. 1  is a side elevational view showing a pair of conventional universal pliers with a quick release mechanism in a locked state; 
         FIG. 2  is a view similar to  FIG. 1 , illustrating the conventional universal pliers with a quick release mechanism in a non-locked state; 
         FIG. 3  is a perspective view of an embodiment of a pair of universal pliers according to the disclosure; 
         FIG. 4  is an exploded perspective view of the embodiment; 
         FIG. 5  is a perspective view of a resilient locking subunit of a quick release mechanism of the embodiment; 
         FIG. 6  is a right side schematic view of the embodiment, with a movable structure shown in a retaining position and the resilient locking subunit in a locked state; 
         FIG. 7  is a perspective view of the quick release mechanism mounted to the movable structure; 
         FIG. 8  is a view similar to  FIG. 6 , illustrating the resilient locking subunit in a non-locking state; 
         FIG. 9  is a view similar to  FIG. 8 , illustrating that a rear movable handle plate is pivoted relative to a front movable handle plate when the resilient locking subunit is in the non-locked state; and 
         FIG. 10  is a view illustrating the movable structure shifted to a releasing position. 
     
    
    
     DETAILED DESCRIPTION 
     Before the present invention is described in greater detail, it should be noted that where considered appropriate, reference numerals or terminal portions of reference numerals have been repeated among the figures to indicate corresponding or analogous elements, which may optionally have similar characteristics. 
     As shown in  FIGS. 3, 4 and 6 , the embodiment of a pair of universal pliers according to the present disclosure includes a fixed structure  2 , a movable structure  3 , a linkage mechanism  4  and a quick release mechanism  5 . 
     The fixed structure  2  shown in the illustrations extends in a front-rear direction (Y) and includes a fixed jaw plate  21  with a fixed clamping portion  211 , a fixed handle plate  22  extending rearward from the fixed jaw plate  21 , and an adjusting screw  23  disposed at a rear end of the fixed handle plate  22 . In this embodiment, the adjusting screw  23  is a bolt rotatably screwed onto the fixed handle plate  22 . 
     The movable structure  3  is movably connected to the fixed structure  2  and includes a movable jaw plate  31 , a front movable handle plate  32  pivotally coupled to and extending rearward from the movable jaw plate  31 , and a rear movable handle plate  33  pivotally coupled to and extending rearward from the front movable handle plate  32 . The movable jaw plate  31  has a movable clamping portion  311  opposed to the fixed clamping portion  211  and forms a clamping hole  200  in conjunction with the fixed clamping portion  211  in closing. The movable jaw plate  32  has a first guide slot  321  at a rear end thereof, a jaw pivot hole  322  at a front end thereof for extension of a securing pin to pivotally couple the movable jaw plate  31  and the front movable handle plate  32 , a front handle pivot hole  323  located in front of the first guide slot  321 , a connecting hole  324  located in front of the front handle pivot hole  323 , and a rod pivot hole  325  located between the jaw pivot hole  322  and the connecting hole  324 . It is to be particularly noted that, the front movable handle plate  32  is formed by a piece of sheet metal bent to form a channel-shaped cross-section with a base and two parallel side walls  320  spaced apart in a left-right direction (X). It is appreciated that the front movable handle plate  32  may also be formed by other processing methods such as molding, cutting, and the like. It should also be noted that each of all the above-mentioned construction holes or slots actually has two opposite left and right ends being formed respectively in the two side walls  320  in this embodiment. 
     The first guide slot  321  is a substantially arcuate slot defining an end configured to be a locked segment  326 , an opposite end configured to be a releasing segment  327 , and an angled portion intermediate between the locked segment  326  and the releasing segment  327  configured to be an intermediate segment  328 . The releasing segment  327  is in front of the locked segment  326  in the front-rear direction (Y) and higher than the locked segment  326  in a top-bottom direction (Z). 
     The rear movable handle plate  33  has a pivoting end  331  pivotally coupled to the front movable handle plate  32  and received between the two side walls  320  of the channel-shaped structure of the front movable handle plate  32 , an opposite grip end  332  disposed at a rear side of the pivoting end  331 , a second guide slot  333  located between the pivoting end  331  and the grip end  332  and registered with the first guide slot  321 , and a bar hook  334  integrally formed at the grip end  332 . The pivoting end  331  is formed with a rear handle pivot hole  335  registered with the front handle pivot hole  323  of the front movable handle plate  32 , so that the rear movable handle plate  33  is capable of pivot relative to the front movable handle plate  32  about the pivot pin  329  extending through the front handle pivot hole  323  and the rear handle pivot hole  335 . The second guide slot  333  has a first end segment  336  and an opposite second end segment  337 , and the second end segment  337  is in front of the first end segment  336  in the front-rear direction (Y). The rear movable handle plate  33  is formed by a piece of sheet metal bent to form a channel shape. Similar to the description of the front movable handle plate  32 , the second guiding slot  333  of the rear movable handle plate  33  actually has two opposite left and right ends being formed respectively in the side walls  320  in this embodiment. 
     The linkage mechanism  4  is operatively disposed with respect to the fixed structure  2  and the movable structure  3 , and includes a linkage bar  41  and a tension spring  42 . The front end of the linkage bar  41  is pivotally coupled to the front movable handle plate  32  with a securing pin extending through the rod pivot hole  325  of the front movable handle plate  32  and the front end of the linkage bar  41 . The linkage bar  41  has a rear end engaging a front end surface of the adjusting screw  23 , and a stop edge  411  on the lower side for abutting against the rear movable handle plate  33 . The tension spring  42  is connected between the movable jaw plate  31  and the fixed handle plate  22 . 
     Referring to  FIGS. 6 and 10 , the linkage mechanism  4  is provided for controlling the shift of the movable structure  3  relative to the fixed structure  2  between a retaining position (see  FIG. 6 ) and a releasing position (see  FIG. 10 ). As shown in  FIG. 6 , when the movable structure  3  is in the retaining position, the grip end  332  of the rear movable handle plate  33  is relatively close to the fixed handle plate  22  of the fixed structure  2 , and the movable clamping portion  311  is adjacent to the fixed clamping portion  211  to form the clamping hole  200  therebetween facilitating firmly gripping an object (not shown). At this position, the rear movable handle plate  33  abuts against the stop edge  411 , the tension spring  42  connected between the movable jaw plate  31  and the fixed handle plate  22  is resiliently stretched. As shown in  FIG. 10 , when the movable structure  3  is shifted to the releasing position, the grip end  332  of the rear movable handle plate  33  is relatively spaced apart from the fixed handle plate  22  of the fixed structure  2 , and the movable clamping portion  311  is pivoted to be far from the fixed clamping portion  211  under the restoring force of the tension spring  42 , the gripped object thus can be released. 
     Referring to  FIGS. 4 to 7 , the quick release mechanism  5  is operatively disposed on the movable structure  3 , and includes a trigger  51 , a fixing pin  52  and a resilient locking subunit  53 . The trigger  51  is pivotally coupled to and accessibly protrudes from the front movable handle plate  32 . In this embodiment, the trigger  51  is formed by bending a piece of sheet metal and has two parallel side walls  510  spaced apart in the left-right direction (X). Each side wall  510  has a hook slot  511  at a top end thereof, a pulling end  512  located lower than the hook slot  511  in the top-bottom direction (Z), and a fixing pin hole  513  located between the hook slot  511  and the pulling end  512 . Each of the hook slot  511  and the fixing pin hole  513  has two opposite left and right ends being formed respectively in the two side walls  510 . The connecting pin  52  extends through the connecting hole  324  of the front movable handle plate  32  and the fixing pin hole  513  to pivotally connect the trigger  51  to the front movable handle plate  32  such that the trigger  51  can be rotated about the fixing pin  52 . In other variations, the trigger  51  can also be a solid structure, and the hook slot  511  and the fixing pin hole  513  can be formed in similar way. The resilient locking subunit  53  includes an movable pin  531  inserted through and slidable along the first guide slot  321  and the second guide slot  333 , a pulling member  532  fixedly connected between the movable pin  531  and the trigger  51 , and a resilient member  533  connected between the movable pin  531  and the bar hook  334  of the rear movable handle plate  33 . The pulling member  532  is of a U-shape consisting of two lateral sections and a front section which interconnects front ends of the two lateral sections. The pulling member  532  has opposite first and second ends  534 ,  535 , which are respectively rear ends of the two lateral sections, connected respectively two ends of the movable pin  531 . The front section of the pulling member  532  engages and is retained in the hook slot  511  of the trigger  51 . In this embodiment, the resilient member  533  is a tension spring having a connecting end  537  mounted to the movable pin  531 , and an opposite hook end  536  retained by the bar hook  334  of the rear movable handle plate  33 , such that the resilient member  533  can be elongated or shortened as the movable pin  531  moves. 
     Referring to  FIGS. 6 and 8 , the trigger  51  can be used to switch the resilient locking subunit  53  from a locked state (see  FIG. 6 ) to a non-locked state (see  FIG. 8 ). As shown in  FIG. 6 , when the resilient locking subunit  53  is in the locked state, the locked segment  326  and the intermediate segment  328  of the first guide slot  321  are respectively registered with the first end segment  336  and the second end segment  337  of the second guide slot  333 . At this time, the movable pin  531  is adjacent to the first end segment  336  of the second guide slot  333  and is located at the locked segment  326  of the first guide slot  321 , and the movable pin  531  is restricted to move only in the front-rear direction (Y). Therefore, the rear movable handle plate  33  cannot pivot relative to the front movable plate  32 , and an object can be firmly gripped by the pliers in this locked state. As shown in  FIG. 8 , when the resilient locking subunit  53  is switched to the non-locked state by pulling rearward on the trigger  51 , the movable pin  531  is driven by the pulling member  532  to position adjacent to the second end segment  337  of the second guide slot  333  and to be located at the intermediate segment  328  of the first guide slot  321  (see  FIG. 6 ), so that the movable pin  531  is released from the restriction and the rear movable handle plate  33  is permitted to pivot relative to the front movable handle plate  32 . Meanwhile, the resilient member  533  is elongated to store a biasing force on the movable pin  531  toward the first end segment  336  of the second guide slot  333  and the locked segment  326  of the first guide slot  321 . 
     Referring to  FIG. 6  and  FIGS. 8 to 10 , when it is needed to release the gripped object, a user can hold the fixed handle plate  22  and the rear movable handle plate  33  of the pliers with one hand and pull rearward on the trigger  51  with one finger of that hand to force the movable pin  531  into the intermediate segment  328 . Then, as shown in  FIG. 9 , using other fingers of that hand to pull up the grip end  332  of the rear movable handle plate  33 , the movable pin  531  thus is forced into the releasing segment  327  of the first guide slot  321 , so that the rear movable handle plate  33  can be pivoted relative to the front movable handle plate  32  to drive the linkage bar  41  to pivot with the movable jaw plate  31  via the abutment of the rear movable handle plate  33  against the stop edge  411  of the linkage bar  41  to convert the movable structure  3  to the releasing position against the resilient force of the tension spring  42  which is configured to pull the movable jaw plate  31  open. Meanwhile, the resilient member  533  returns to its original configuration and brings the resilient locking subunit  53  to the locked state for the next use. As can be seen from the above, the user can manipulate the universal pliers of the present embodiment with one hand and keep another hand free. 
     In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment. It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to “one embodiment,” “an embodiment,” an embodiment with an indication of an ordinal number and so forth subunit that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects, and that one or more features or specific details from one embodiment may be practiced together with one or more features or specific details from another embodiment, where appropriate, in the practice of the disclosure. 
     While the disclosure has been described in connection with what is considered the exemplary embodiment, it is understood that this disclosure is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.