Abstract:
A push-button locking pliers has a plurality of macro jaw width stations for grasping a wide variety of objects. A positioning mechanism is connected to a movable jaw member and cooperates with a jaw adjustment slot in the main handle. The positioning mechanism is released by pushing on a push button allowing, it to move along the slot. The user places the positioning mechanism at the jaw positioning station that creates a macro spacing between the fixed and movable jaws that best fits the object to be grasped. An adjustment screw adjusts the micro spacing between the jaws to cause the pliers to lock on the object using an over-center mechanism when the handles are squeezed.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims the filing benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/814,946, filed Jun. 19, 2006, which is included herein by reference. 

   TECHNICAL FIELD 
   The present invention relates generally to the field of hand tools, and more particularly to locking pliers having jaws that are selectively spaced apart in one of a plurality of positions to accommodate objects of various sizes prior to engaging the locking mechanism. 
   BACKGROUND OF THE INVENTION 
   Locking pliers are well known in the art. These devices have two jaws that may be locked on an object. The over-center locking mechanism is achieved by two handles, a fixed jaw on one of the handles, a movable jaw, a pivoting link between the handles, and an over-center spring between the movable jaw and the fixed jaw handle that together cooperate to lock the jaws on a work piece when the handles are forced together. The over-center mechanism includes a micro adjustment screw that controls the opening of the jaws over a limited range to accommodate articles of different sizes within the range and permits the over-center mechanism to lock. An example of such locking pliers is shown in U.S. Pat. No. 4,730,524 to Petersen that also includes a summary of the many Petersen Vise-Grip patents. 
   In addition to the micro adjustment screw for setting up the jaw spacing, some locking pliers include macro jaw opening mechanisms to allow use on a much wider range of work pieces. For example, U.S. Pat. No. 2,399,454 to Snell locates the jaw pivot in a slot in the upper jaw handle that is perpendicular to the upper jaw. The jaw pivot is adjusted along the slot by a screw with a head above the upper jaw handle. Turning the screw one way places the jaws closer together. Turning the screw the other way places the jaws further apart. Because of the fine spacing between the jaws that is possible using the screw, no separate micro adjustment screw in the handle is needed to set up the over-center locking mechanism as is found in the Peterson Vise-Grips. 
   U.S. Pat. Nos. 2,905,038 and 3,241,410 both to Paden have a long shank on the lower jaw holder. The lower jaw can be slid along the shank to determine the spacing between the jaws. The side of the shank has a series of teeth for holding the jaw. A pawl on the lower jaw engages any one of the teeth on the shank to hold the lower jaw in a given position relative to the upper jaw. Twenty-three positions are available on the embodiment shown in U.S. Pat. No. 2,905,038. Twenty positions are available on the embodiment shown in U.S. Pat. No. 3,241,410. 
   U.S. Pat. No. 3,672,245 to Hoffman is similar to Snell in that it has a slot perpendicular to the upper jaw in the upper jaw handle for holding the jaw pivot. But instead of using a screw to determine the location of the pivot in the slot, the position is determine by arcuate channels adjacent the slot for holding the lower jaw pivot ata desired spacing from the fixed upper jaw. Movement between the arcuate channels is achieved by loosening a nut on the pivot until the movable jaw can be slipped over the arcuate channels to a different set of arcuate channels. The nut is then tightened on the pivot to hold the pivot at a selected set of arcuate channels. Seven positions are available on the embodiment shown. 
   U.S. Pat. No. 3,981,209 to Caroff shows a locking pliers where the length of the link between the two handles is adjustable to control both the micro and macro jaw adjustment functions. Again a slot perpendicular to the upper jaw as in Hoffman and Snell is provided in the upper jaw handle. The length of the link is first adjusted to allow the pivot for the movable jaw to be moved in the slot toward or away from the fixed jaw. When the desired position is reached, the pivot is pushed into one of a plurality of teeth on the side of the slot opposite the link. The jaws are then moved around the work piece and the length of the link is further adjusted until the micro jaw adjustment is achieved that causes the jaws to lock on the work piece using the over-center principle when the handles are squeezed together. Five positions are available on the embodiment shown. 
   U.S. Pat. Nos. 6,578,452 and 5,022,290 both to Duffy have an upper jaw on a slide that moves in a slot in the lower jaw holder. The edge of the slide has a plurality of teeth for holding the jaw. A lock engages any one of the teeth to hold the upper jaw in a desired position with respect to the lower jaw. Three positions are available on the embodiment shown in U.S. Pat. No. 5,022,290. Thirty positions are available on the embodiment shown in U.S. Pat. No. 6,578,452. 
   U.S. Pat. No. 5,385,072 to Neff also has a slot in the holder for the lower jaw but moves the lower jaw in the slot instead of the upper jaw as in Duffy. Pins through the slot hold the lower jaw. The position of the lower jaw relative to the upper jaw is determined by an adjusting lever. About twelve positions are available on the embodiment shown. Jaw adjustment mechanisms are also known in non-locking pliers. For example, U.S. Pat. No. 4,581,960 to Putsch shows a pliers having two handles that cross each other and are connected together by a pivot. The pivot is attached to one of the handles and slides in a slot in the other handle to change the gap between the jaws. The sides of the slot have teeth. The pivot is mounted in a rectangular block having teeth on the sides matching the teeth on the sides of the slot. A push button on the end of the pivot is pushed to move the rectangular block out of the slot. This allows the pivot to be moved along the slot to a new position. When the push button is released, a spring on the other end of the pivot forces the rectangular block back into the slot where the teeth once again engage each other locking the pivot at a desired location. About twelve positions are available on the embodiment shown. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention is directed to a push-button locking pliers having a plurality of macro jaw width stations for grasping a wide variety of objects. A positioning mechanism is connected to a movable jaw member and cooperates with a jaw adjustment slot in the main handle. The positioning mechanism is released by pushing on a push button allowing it to move along the slot. The user places the positioning mechanism at the jaw positioning station that creates a macro spacing between the fixed and movable jaws that best fits the object to be grasped. An adjustment screw adjusts the micro spacing between the jaws to allow the pliers to lock on the object using an over-center mechanism when the handles are squeezed. 
   In accordance with a preferred embodiment, the main handle has a fixed jaw, an adjustment slot with a plurality of jaw positioning stations, and a distal end spaced from the fixed jaw with an adjustment screw. A locking handle having a jaw end and a distal end is under the main handle. A movable jaw member is pivotally coupled to the jaw end of the locking handle and has a movable jaw and the positioning mechanism. The positioning mechanism includes a pivot with an engaged position and a disengaged position, a pivot spring for biasing the pivot in the engaged position, and a push button for pushing the pivot out of the engaged position against the bias of the pivot spring. The pivot is positioned in the adjustment slot and pivotally connects the main handle to the movable jaw member. The pivot is movable by pressing the push button to disengage the pivot. After it is moved to one of the other jaw positioning stations, it is engaged in the new stations by releasing the push button. A link member is pivotally connected to the locking handle and engages the adjustment screw to provide the micro adjustment of the pliers. An over-center spring is connected between the main handle and the movable jaw member and holds the end of the link against the adjustment screw. The main handle with the fixed jaw and adjustment screw, the locking handle with the link member, the movable jaw member with the movable jaw, and the over-center spring comprise an over-center mechanism for locking the fixed and movable jaws on an object. 
   In a feature of the embodiment, three jaw positioning stations are provided along the slot. The user initially selects one of the three stations to best position the pliers on an object. 
   In accordance with a preferred embodiment, each jaw positioning station includes a rounded hole. The pivot has a longitudinal axis with a rounded shoulder substantially matching the rounded hole, a reduced portion less than the size of the rounded hole, and a push button on the end that is biased away from the rounded hole by the pivot spring. The pivot spring biases the pivot along the longitudinal axis. The rounded shoulder is positioned in the rounded hole by the pivot spring when the push button is not pushed thereby causing the movable jaw member to pivot on the main handle at the jaw positioning station. When the pivot is pushed along its longitudinal axis by the push button, the reduced portion is positioned in the rounded hole allowing the pivot to be moved between positioning stations. In accordance with an alternative embodiment of the invention, the pivot is modified to have two rounded shoulders substantially matching the rounded hole, two substantially parallel flats along the longitudinal axis between the two rounded shoulders, and the pivot spring biases the pivot rotationally about the longitudinal axis. When the push button is not pushed, the two rounded shoulders are positioned in the rounded hole by the pivot spring thereby pivoting the movable jaw member on the main handle at the jaw positioning station. When the push button is pushed, the two parallel flats are positioned in the rounded hole thereby allowing the pivot to be moved between positioning stations. 
   In other alternative embodiments, a plurality of teeth are provided along the sides of the slot or the face of the handle to provide the macro jaw spacing adjustment. In accordance with another aspect of the invention, the plurality of jaw positioning stations includes a most closed jaw positioning station and an opposite most open jaw positioning station. The jaws may be moved to the most closed position by pushing the push button to release the pivot and allowing the over-center spring to pull the positioning mechanism to the most closed jaw positioning station. 
   In accordance with a feature of the invention, the process of moving the positioning mechanism to the most closed jaw positioning station may be enhanced by manually pressing the fixed jaw and movable jaw together after the push button has been pressed. 
   In accordance with another aspect of the invention, the jaws may be moved to the most open position by pushing the push button to release the pivot and pressing the distal ends of the main and locking handles together pivoting the fixed and movable jaws apart around where the link member engages the adjustment screw. 
   Other aspects of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevation view of a push button multi-position locking pliers in accordance with the present invention showing the jaws in a most closed position; 
       FIG. 2  is a side elevation view of the locking pliers of  FIG. 1  showing the conventional clamping action of the over-center mechanism; 
       FIG. 3  is a side elevation view of the locking pliers in a most open position; 
       FIG. 4  is side elevation view of the locking pliers of  FIG. 3  showing the conventional clamping action of the over-center mechanism; 
       FIG. 5  is a top plan view of the locking pliers; 
       FIG. 6  is an enlarged cross sectional view along the line  6 - 6  of  FIG. 5 ; 
       FIG. 7  is an enlarged cross sectional view similar to  FIG. 6  with the push button pushed disengaging the pivot; 
       FIG. 8  is a side elevation view showing how the jaws of the locking pliers are moved from a most closed position to a most open position; 
       FIG. 9  is a side elevation view of the locking pliers showing a second embodiment of the adjustment slot and positioning mechanism having a rotary pivot release; 
       FIG. 10  is an opposite side elevation view of the embodiment of  FIG. 9 ; 
       FIG. 11  is a top plan view of the embodiment of  FIG. 9 ; 
       FIG. 12  is an exploded view of the positioning mechanism of the embodiment of  FIG. 9 ; 
       FIG. 13  is a side elevation view of the locking pliers showing a third embodiment of an adjustment slot and positioning mechanism having teeth in the slot; and, 
       FIG. 14  is a side elevation view of the locking pliers showing a fourth embodiment of the adjustment slot and positioning mechanism having teeth on the face of the main handle. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  illustrates a side elevation view of a push button multi-position locking pliers for grasping an object in accordance with the present invention showing the jaws in a most closed position, the locking pliers generally designated as  20 . Locking pliers  20  includes a main handle  22  having a fixed jaw  24 , an adjustment slot  26  having a plurality of jaw positioning stations  28 ,  30 ,  32 , and a distal end  34  spaced from the fixed jaw having an adjustment screw  36 . The plurality of jaw positioning stations  28 ,  30 ,  32  includes a most closed jaw positioning station  28  shown being used in  FIG. 1  and an opposite most open jaw positioning station  32  shown being used in  FIG. 3 . In the embodiment of the invention shown in the drawings, three jaw positioning stations  28 ,  30 ,  32  are provided, each jaw positioning station having a rounded hole  38  with a reduced portion  40  between the holes to create the slot. Other possible configurations for jaw positioning stations are shown in  FIGS. 13 and 14 . Three jaw positioning stations have been found to be useful because they provide a wide range of macro jaw openings in the pliers which is limited only by the width of the pliers from the top to the bottom while retaining enough of the rounded holes of the positioning stations to support the forces on the pivot  42  between the jaws. 
   A locking handle  44  is located below the main handle and has a jaw end  46 , a distal end  48  spaced from the jaw end, and a link member  50  pivotally connected to the locking handle by a link pivot  52 . The opposite end  54  of the link member  50  abuts the end  56  of the adjustment screw  36  in the main handle  22  shown by the broken lines to provide micro jaw opening adjustments in a manner well known in the over-center locking pliers art. A movable jaw member  58  having a movable jaw  60  is pivotally connected to the jaw end  46  of the locking handle  44  by a locking handle pivot  62  and has a positioning mechanism  64 . The positioning mechanism  64  engages adjustment slot  26  and is selectively movable to all of the jaw positioning stations  28 ,  30 ,  32 . In  FIG. 1 , positioning mechanism  64  has been moved to the jaw positioning station  28  that causes fixe&#39;d jaw  24  and movable jaw  60  to be in a most closed position. 
   The positioning mechanism  64  includes the pivot  42 . The pivot has a locked position as shown in  FIG. 6  and a disengaged position as shown in  FIG. 7 . A pivot spring biases the pivot in the locked position. A push button  66  is used to push the pivot  42  out of the locked position against the pivot spring bias so the pivot can be moved to another positioning station such as stations  30  or  32 . The pivot  42  positioned in the adjustment slot  26  pivotally connects the main handle  22  to the movable jaw member  58 . After the pivot is moved to a new jaw positioning station, the push button is released and the pivot spring pushes the pivot back into a locked position in the new jaw positioning station. 
   An over-center spring  68  shown in  FIGS. 3 ,  4 , and  8  is connected between the main handle  22  and the movable jaw member  58  to keep the end  54  of link member  50  pressed against the end  56  of adjustment screw  36  in a manner well know in the prior art. Main handle  22 , adjustment screw  36 , locking handle  44 , movable jaw member  58 , and over-center spring  68  comprise a conventional over-center mechanism that clamps fixed jaw  24  and movable jaw  60  on an object  500 . 
     FIG. 2  is a side elevation view of locking pliers  20  showing the conventional clamping action of the over-center mechanism with fixed jaw  24  and movable jaw  60  on an object  500 . The positions of locking handle  44 , link member  50 , and movable jaw member  58  prior to clamping are shown in broken lines. 
     FIG. 3  is a side elevation view of locking pliers  20  in the most open position. Positioning mechanism  64  has been moved to, the jaw positioning station  32  at the bottom of the slot  26  that causes fixed jaw  24  and movable jaw  60  to be the furthest apart. In this position, the jaws can clamp on a larger object  500  than is possible in the position shown in  FIGS. 1 and 2 . Over-center spring  68  is connected between main handle  22  and movable jaw member  58  keeping the end  54  of link member  50  pressed against the end  56  of adjustment screw  36 . 
     FIG. 4  is side elevation view of the locking pliers of  FIG. 3  showing the conventional clamping action of the over-center mechanism that clamps fixed jaw  24  and movable jaw  60  on the larger object  500 . The positions of locking handle  44 , link member  50 , and movable jaw member  58  prior to clamping are shown in broken lines. If an intermediate macro jaw width adjustment is desired, the positioning mechanism  64  is moved to the jaw positioning station  30  in the middle between the positions shown in  FIGS. 1 and 3 . The micro jaw width adjustment required by all over-center locking pliers to lock on any give object is provided in all three positioning stations by the end  56  of adjustment screw  36  abutting the end  54  of link member  50  in a manner well know in the art. 
     FIG. 5  is a top plan view of locking pliers  20  showing pivot coil spring  70  of positioning mechanism  64  biasing pivot  42  in a jaw positioning station such as positioning station  32  of  FIGS. 1 and 2  by pushing the push button  66  on the end of pivot  42  away from the first side  72  of main handle  22 . The positioning mechanism is disengaged by pushing push button  66  toward the first side  72  of main handle  22  against the bias of pivot spring  70 . 
     FIG. 6  is an enlarged cross sectional view along the line  6 - 6  of  FIG. 5 . Positioning mechanism  64  includes pivot  42  that is selectively movable between a locked position shown in  FIG. 6  and a disengaged position shown in  FIG. 7 . Pivot  42  has a longitudinal axis  74 , rounded shoulders  76  that match the rounded holes  38  of adjustment slot  26 , a reduced portion  78  less than the size of the rounded holes  38 , and the push button  66 . The pivot spring  70  biases the pivot along the longitudinal axis  74  away from the side  72  of main handle  22  so that rounded shoulders  76  engage the rounded hole  38  of jaw positioning station  32  thereby locking pivot  42  in place (refer to  FIGS. 1 and 2 ). Movable jaw member  58  then pivots about main handle  22  at that location. 
     FIG. 7  is an enlarged cross sectional view similar to  FIG. 6  showing positioning mechanism  64  moved to the disengaged position. The movable jaw member  58  is positioned in the space  75  between the first and second sides  72 ,  73  of main handle  22 . The disengaged position is achieved by pressing push button  66  on the end of pivot  42  along its longitudinal axis  74  in the direction indicated by arrow  80  toward main handle  22  against the bias of pivot spring  70 . This causes first rounded shoulder  76  to move out of first rounded hole  38  of first side  72  and second rounded shoulder  77  to move out of second rounded hole  39  of second side  73  in the main handle  22  on both sides of the movable jaw member  58 . The upper second rounded shoulder  77  as shown in the drawing moves above the upper second side  73  of the main handle while the lower first rounded shoulder  76  moves into a relief  82  in movable jaw member  58  thereby permitting the reduced portion  78  of pivot  42  to be moved along jaw adjustment slot  26  to another jaw positioning station. 
     FIG. 8  is a side elevation view showing how jaws  24  and  60  of locking pliers  20  are moved from a most closed position to a most open position at jaw positioning station  32 . Starting from the most closed position of  FIG. 1 , a user simultaneously disengages positioning mechanism  64  by pressing push button  66  toward the first side  72  of main handle  22  (refer to  FIG. 7 ) and manually urges the distal ends  24  and  48  of the main handle  22  and locking handle  44  together. This causes locking handle  44  to pivot on main handle  22  about where end  54  of link member  50  and end  56  of adjustment screw  36  abut. In so doing, this forces jaws  24  and  60  apart to the most open position shown against the pull of over-center spring  68 . As shown in  FIG. 8 , locking handle  44  is at least as long as main handle  22  to allow both to be gripped simultaneously by one hand of a user so that distal ends  24  and  48  can be urged together as shown by the arrows. Also as shown in the drawing, the length of the outer portion of the locking handle  44  from the handle pivot point to distal end  48  and the length of the inner portion from the handle pivot point to the jaw end  46  ( FIG. 1 ) are substantially the same. When the most open position is reached, push button  66  is released allowing pivot spring  70  under push button  66  to lock the pivot in the new positioning station as shown in  FIG. 6 . 
   Conversely, the most closed position of  FIG. 1  may be achieved from a more open position such as shown in  FIG. 8  by pressing push button  66  of pivot  42  to disengage pivot  42  as shown in  FIG. 7 . Over-center spring  68  then pulls movable jaw members  58  toward main handle  22  thereby placing jaws  24  and  60  in their most closed position. The narrowing can be facilitated by manually pressing the fixed jaw  24  and movable jaw  60  together. 
     FIG. 9  is a side elevation view of the locking pliers showing a second embodiment of the adjustment slot and positioning mechanism having a rotary pivot release instead of a longitudinal pivot release, the locking pliers generally designated as  220 . Locking pliers  220  includes a main handle  222  having a fixed jaw  224 , an adjustment slot  226  having a plurality of jaw positioning stations  228 ,  230 ,  232 , and a distal end  234  spaced from the fixed jaw having an adjustment screw  236 . In the embodiment of the invention shown in the drawings, three jaw positioning stations are provided, each jaw positioning station having a rounded hole  238  with a reduced portion  240  between the holes to create the slot. 
   A locking handle  244  is located below the main handle and has a jaw end  246 , a distal end  248  spaced from the jaw end, and a link member  250  pivotally connected to the locking handle by a link pivot  252 . The opposite end  254  of the link member engages end  256  of adjustment screw  236  in the main handle to provide micro jaw opening adjustments in a manner well known in the over-center locking pliers art. A movable jaw member  258  having a movable jaw  260  is pivotally connected to the jaw end  246  of the locking handle  244  by a locking handle pivot  262  and has a positioning mechanism  264 . The positioning mechanism  264  engages adjustment slot  226  and is selectively movable to all of the jaw positioning stations  228 ,  230 ,  232 . In  FIG. 9 , positioning mechanism  264  has been moved to the middle jaw positioning station  230 . 
   The positioning mechanism  264  includes a pivot  242  having an engaged positions as shown in  FIG. 9  and a disengaged position when rotated 90 degrees. A pivot spring  270  biases the pivot in the engaged position. A push button  266  is used to rotate the pivot 90 degrees out of the engaged position against the pivot spring bias so the pivot can be moved to another positioning station. The pivot  242  positioned in the adjustment slot  226  pivotally connects the main handle  222  to the movable jaw member  258 . After the pivot is moved to a new jaw positioning station, the push button  266  is released allowing the pivot spring  270  to push the pivot back into an engaged position in the new jaw positioning station. A guide means  290  comprised of a wall  292  on main handle  222  parallel to slot  226  and between slot  226  and the over-center spring and a washer  294  on pivot  242  having a flat side  296  that abuts wall  292  keeps pivot  242  in the middle of the slot when it is moved between jaw positioning stations  228 ,  230 ,  232 . As noted above in the description of  FIG. 8 , the over-center spring, which is not shown in  FIG. 9  but is identical to over-center spring  68  in  FIGS. 3 ,  4 , and  8 , pulls movable jaw member  258  and with it pivot  242  toward main handle  222 . Without guide means  290 , the over-center spring would pull pivot  242  against the right side of slot  226  as shown in  FIG. 9  making it difficult to align pivot  242  with a new positioning station because it would not be in the center of the slot when it reached the new positioning station. Guide means  290  facilitates the positioning of pivot  242  at a new positioning station because it always keeps pivot  242  in the middle of the slot. The remaining features of the second embodiment  220  shown in  FIG. 9  are identical to those shown in  FIGS. 1-4 . 
     FIG. 10  is an opposite side elevation view of the second embodiment of  FIG. 9  showing the features of the pivot  242  in relation to the rounded hole  238  of the middle positioning station  230  of jaw adjustment slot  226  in broken lines. Pivot  242  has two rounded shoulders  284  substantially matching the round hole  238  of positioning station  230  that provide the surfaces on which movable jaw member  258  pivots in relation to main handle  222 . Pivot  242  also has two substantially parallel flats  286  along its longitudinal axis between the two rounded shoulders  284 . When the push button  266  of  FIG. 9  is pushed 90 degrees to rotate the pivot 90 degrees, the rounded shoulders move out of the rounded hole of positioning station  230  into the reduced portion  240  of adjustment slot  226  between the positioning stations. Pivot  242  may then be moved along adjustment slot  226  to a new positioning station by passing the flats  286  between the positioning stations. When the new positioning station is reached, the push button  266  is released allowing the pivot spring  270  to rotate the pivot back to an engaged position where the two rounded shoulders  284  of the pivot match the rounded hole  238  of the new positioning station. 
     FIG. 11  is a top plan view of the second embodiment of  FIG. 9 . The push button  266  is pushed down 90 degrees to rotate the pivot  242  about longitudinal axis  274  so positioning mechanism  264  may be moved in relation to main handle  222 . Guide means  290  comprised of wall  292  parallel to the slot and between the slot and the over-center spring and a washer  294  on pivot  242  having a flat side  296  that abuts wall  292  keeps pivot  242  in the middle of the slot when it is moved between the jaw positioning stations. 
     FIG. 12  is an exploded view of the positioning mechanism of  FIG. 9 . Pivot  242  has two rounded shoulders  284  and two substantially parallel flats  286  along its longitudinal axis  274 . When the push button  266  is pushed against the bias of pivot spring  270 , pivot  242  is rotated putting the parallel flats in a position to pass between the positioning stations shown in  FIGS. 9 and 10 . The guide means for keeping the pivot  242  in the middle of the slot when it is moved between the jaw positioning stations includes washer  294  on pivot  242  having flat side  296  that abuts the wall to keep pivot  242  in the middle of the slot when it is moved between the jaw positioning stations. 
     FIG. 13  is a side elevation view of a third embodiment of the locking pliers with a different adjustment slot and positioning mechanism, generally designated  320 . Both sides of adjustment slot  326  have a plurality of slot teeth  390  and the distal end  343  of pivot  342  has a plurality of pivot teeth  392  that engage the slot teeth to hold the positioning mechanism  364  and any selected jaw positioning station. All other aspects of this embodiment are the same as for the first embodiment of  FIGS. 1-8  which are incorporated herein by reference. The positioning mechanism  364  is disengaged by pressing on the push button on the other side of pliers  320  to lift the pivot teeth out of the slot teeth freeing the positioning mechanism to move to a new jaw positioning station along adjustment slot  326 . 
     FIG. 14  is a side elevation view of a fourth embodiment of the locking pliers with a different adjustment slot and positioning mechanism, generally designated  420 . The side  472  of main handle  422  adjacent adjustment slot  426  has a plurality of face teeth  490  and the distal end  443  of pivot  442  has a plurality of pivot teeth  492  that engage the face teeth to hold the positioning mechanism  464  at any selected jaw positioning station. The face teeth  490  of this embodiment are perpendicular to the slot teeth  390  of the third embodiment. All other aspects of this embodiment are the same as for the first embodiment of  FIGS. 1-8  which are incorporated herein by reference. The positioning mechanism  464  is disengaged by pressing on the push button on the other side of pliers  420  to lift the pivot teeth off of the face teeth freeing the positioning mechanism to move to a new jaw positioning station along adjustment slot  426 . 
   In terms of use, a method for placing the jaws of the locking pliers shown in a most closed position includes: 
   (a) providing locking pliers  20 , including;
         a main handle  22  having a fixed jaw  24 , an adjustment slot  26  having a plurality of jaw positioning stations  28 ,  30 ,  32 , and a distal end  34  spaced from the fixed jaw having an adjustment screw  36 ;   a locking handle  44  having a jaw end  46  and a distal end  48  spaced from the jaw end;   a movable jaw member  58  pivotally coupled to the jaw end  46  of the locking handle  44  and having a movable jaw  60  and a positioning mechanism  64 ;   the positioning mechanism having a pivot  42  with a disengaged position and a disengaged position, a pivot spring  70  for biasing the pivot in the engaged position, and a push button  66  for pushing the pivot out of the engaged position against the pivot spring bias;   the pivot positioned in the adjustment slot to pivotally connect the main handle to the movable jaw member and movable by pressing the push button to unlock the pivot and move the pivot to one of the plurality of jaw positioning stations and lock in the one of the plurality of jaw positioning stations upon release of the push button;   a link member  50  pivotally connected to the locking handle and engaging the adjustment screw;   an over-center spring  68  connected between the main handle and the movable jaw member;   the main handle with the fixed jaw and the adjustment screw, the locking handle, the movable jaw member with the link member, and the over-center spring comprising an over-center mechanism for locking the fixed and movable jaws on the object; and,   the plurality of jaw positioning stations including a most closed jaw positioning station  28 , and an opposite most open jaw positioning station  32 ;       

   (b) with positioning mechanism  64  not in most closed jaw positioning station  28 , pressing push button  66  thereby disengaging positioning mechanism  64  and positioning mechanism  64  to be urged to the most closed jaw positioning station by over-center spring  68 ; and, 
   (c) allowing over-center spring  68  to pull positioning mechanism  64  to the most closed jaw positioning station  28 . 
   The method further including: 
   simultaneously with step (b), manually pressing fixed jaw  24  and movable jaw  60  together. 
   Conversely, a method for placing the jaws of locking pliers in a most open position includes: 
   (a) providing locking pliers  20 , including;
         a main handle  22  having a fixed jaw  24 , an adjustment slot  26  having a plurality of jaw positioning stations  28 ,  30 ,  32 , and a distal end  34  spaced from the fixed jaw having an adjustment screw  36 ;   a locking handle  44  having a jaw end  46  and a distal end  48  spaced from the jaw end;   a movable jaw member  58  pivotally coupled to the jaw end  46  of the locking handle  44  and having a movable jaw  60  and a positioning mechanism  64 ;   the positioning mechanism having a pivot  42  with an engaged position and an disengaged position, a pivot spring  70  for biasing the pivot in the engaged position, and a push button  66  for pushing the pivot out of the engaged position against the pivot spring bias;   the pivot positioned in the adjustment slot to pivotally connect the main handle to the movable jaw member and movable by pressing the push button to unlock the pivot and move the pivot to one of the plurality of jaw positioning stations and lock in the one of the plurality of jaw positioning stations upon release of the push button;   a link member  50  pivotally connected to the locking handle and engaging the adjustment screw;   an over-center spring  68  connected between the main handle and the movable jaw member; the main handle with the fixed jaw and the adjustment screw, the locking handle, the movable jaw member with the link member, and the over-center spring comprising an over-center mechanism for locking the fixed and movable jaws on the object; and,   the plurality of jaw positioning stations including a most closed jaw positioning station  28 , and an opposite most open jaw positioning station  32 ;       

   (b) with positioning mechanism  64  not in the most open jaw positioning station, simultaneously pressing push button  66  thereby disengaging positioning mechanism  64 , and manually urging distal ends  34  and  48  of main handle  22  and locking handle  44  together. 
   The preferred embodiments of the invention described herein are exemplary and numerous modifications, variations, and rearrangements can be readily envisioned to achieve an equivalent result, all of which are intended to be embraced within the scope of the appended claims.