Patent Publication Number: US-6711789-B2

Title: Clamp

Description:
BACKGROUND 
     The present invention relates to a clamp and more particularly to an improved clamp in which the jaws can be easily locked in a predetermined position around an article and in which the jaws can be easily unlocked from said predetermined position to release the article. 
     A number of clamps have been used in the past to hold articles. Some of these clamps have means for locking the jaws of the clamp in a predetermined gripping position around an article and for unlocking them to release the article. Some of these previous clamps are complicated to operate as well as expensive to manufacture and maintain. 
     Objects 
     The present invention avoids these drawbacks and has for one of its objects the provision of an improved clamp in which the jaws can be easily locked in a predetermined position around an article and in which the jaws can be easily unlocked to release the article. 
     Another object of the present invention is an improved clamp which is simple to operate and maintain. 
     Another object of the present invention is an improved clamp which is inexpensive to manufacture and maintain. 
     Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to be described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice. 
    
    
     DRAWINGS 
     A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification, wherein: 
     FIG. 1 is an exploded perspective view showing the various parts of the clamp of the present invention. 
     FIG. 2 is a perspective view of the clamp in its open position 
     FIG. 3 is a plan view showing the clamp locked in position to hold an article. 
     FIG. 4 is a sectional view showing the clamp in its open position. 
     FIG. 5 is a sectional view showing the clamp in its closed position. 
     FIG. 6 is a sectional view detail showing the manner of unlocking the jaws. 
     FIG. 7 is a sectional view showing the jaws in an open position. 
    
    
     DESCRIPTION 
     With specific reference to the drawings, the clamp  1  of the present invention comprises a pair of one piece first and second handle assemblies  2  and  3  each having, respectively, a jaw  4  and  5 , a hand grip  6  and  7  and an intermediate portion  8  and  9 , which connect hand grip  6  and jaw  4  together and hand grip  7  and jaw  5  together, respectively. Each of the hand grips  6  and  7  is preferably hollow with the hand grips  6  and  7  each having spaced inner side walls  39  and a base  38 . The handle assemblies  2  and  3  are pivotally mounted to each other at their intermediate portions  8  and  9  by means of a pivot pin  10  and nut  11  extending through openings  12  in said intermediate portions  8  and  9 . The handle assemblies  2  and  3  cross each other at the pivot pin  10  so that where the hand grips  6  and  7  are moved together the jaws  4  and  5  are moved together and when the hand grips  6  and  7  are moved apart, the jaw  4  and  5  will move apart. Each of the jaws  4  and  5  has a grip pad  15  pivotally mounted to the end of each jaw  4  and  5  which are adapted to grip an article A therebetween (FIG.  3 ). Mounted around the pivot pin  10  is a spring assembly  19  comprising a coiled head portion  16  wound around pivot pin  10 , legs  17  extending from the head portion  16  and lock pins  18  bent at an angle to the legs  17 . The spring assembly  19  is adapted to fit in a cavity  20  provided in each of the intermediate portions  8  and  9  with the bent legs  17  extending into holes  21  in each of the intermediate portions  8  and  9 . The legs  17  of the spring assembly  19  are biased to exert outward pressure on the handle assemblies  2  and  3  to bias the jaws  4  and  5  and hand grips  6  and  7  of the handle assemblies  2  and  3  in an open position and permits the jaws  4  and  5  and hand grips  6  and  7  of the handle assemblies  2  and  3  to be moved toward each other against the bias of the spring assembly  19 . 
     Releasable locking means are provided in the hollow hand grips  6  and  7  which cooperate with each other to hold the jaws  4  and  5  in an open position. The hand grip  7  of the second handle assembly  3  is provided with a curved toothed rack  30  between its side walls  39  extending from its base  38  and having a plurality of teeth  31  thereon. The hollow hand grip  6  of the first handle assembly  2  has a pawl  32  and a spring pressed trigger assembly  40  mounted thereon. The pawl  32  has a head  33  having a plurality of teeth  34  and a tail  35  having an arcuate slot  36  and an open end groove  37 . The pawl  32  is mounted in the trigger assembly  40  which includes a finger portion  41  and a body  49  comprising spaced plates  42 . Each of the spaced plates  42  have spaced openings  43  and  44  with the openings  43  and  44  of one plate  42  being aligned with the openings  43  and  44  of the other plate  42 . The tail  35  of the pawl  32  is inserted between the spaced plates  42  of the trigger assembly  40  so that the open end groove  37  and arcuate slot  36  in the tail  35  are aligned with the openings  43  and  44 , respectively, in the spaced plates  42 . A spring  45  having a coiled head  48  with legs  46  and  47  extending therefrom is mounted over the space plates  42  so that the head  48  is in alignment with spaced plate openings  43  and open end groove  37  in tail  35  of pawl  32 . A pin  50  is inserted through the head  48 , openings  43  one open end groove  37  and is attached by any well known means to the inner opposed side walls  39  of the hollow hand grip  6  so that pin  50  holds the pawl  32 , trigger assembly  40  and spring  45  together and permits the trigger assembly  40  to pivot relative to the hand grip  6  and pawl  32 . Another pin  51  is mounted in the second openings  44  in the spaced plates  42  and extends through the arcuate slot  36  in the tail  35  to limit the movement of the trigger assembly  40  relative to the pawl  32  to the confines of the arcuate slot  36 . The leg  47  of the spring  45  is mounted against the base  38  of the hollow hand grip  6  and the leg  46  of the spring  45  is mounted between spaced plates  42  so that the spring  45  exerts an outward bias on the finger assembly  40  to push and bias the pawl  32  outwardly toward the rack  30 . When the finger piece  41  is pressed inwardly toward the hollow hand grip  6  by the user, the pawl  32  will move inwardly away from the rack  30  against the bias of the spring  45 . When the finger piece  40  is released, the spring assembly  45  will force the finger  40  and the pawl  32  outwardly toward the rack  30 . 
     With this structure, the jaws  4  and  5  are moved together by compressing the hand grips  6  and  7  toward each other against the bias of spring  19  until the grip pads  15  grasp and hold an article A therebetween. The teeth  34  of the pawl  32  move along the teeth  31  of the rack  30  and since the pawl  32  is biased toward the rack  31 , when the article gripping position is reached the teeth  34  of the pawl  32  will enter and mesh with the teeth  31  in the rack  30  to lock the jaws  4  and  5  in the article holding position. When it is desired to release the article A, the finger piece  41  is pressed inwardly by the user against the action and bias of the spring  45  to move the teeth  34  of the pawl  33  away from the teeth  31  of the rack  30 , hence permitting the spring assembly  19  to automatically open the hollow handle grips  6  and  7  and the jaws  4  and  5  thereby releasing the article A from between the grip pads  15 . 
     It will then be seen that the present invention provides an improved clamp in which the jaws can be easily locked into a predetermined position around an article, in which the jaws can be easily unlocked to release the article, which is simple to operate and maintain and which is inexpensive to manufacture and maintain. 
     As many and varied modifications of the subject matter of this invention will become apparent to those skilled in the art from the detailed description given hereinabove, it will be understood that the present invention is limited only as provided in the claims appended hereto.