Abstract:
A hand-held cable tie tensioning and severing tool including a gripping mechanism having a pawl and a pawl hood, wherein the underside of the pawl hood is provided with a texture pattern.

Description:
RELATED APPLICATION 
       [0001]    This application claims the benefit of co-pending U.S. Provisional Patent Application Ser. No. 62/212,806 entitled “Pawl Shroud with Textured Surface”, filed 1 Sep. 2015. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to hand held tensioning and cutting tools, and particularly to an improved hand tool for tensioning and cutting cable ties. 
         [0003]    Cable ties are widely used in a variety of environments and applications. They may be used, for example, to bundle a plurality of elongate wires, cables, or other elongate articles. Cable ties may also be used to secure elongate articles to rigid structures or used as hose clamps, by way of example. Such cable ties typically include an elongate tie tail portion and a head portion. The elongate tie tail portion may be threaded through the integral head portion to encircle the elongate articles to be bound. In use, a hand held tensioning and cutting tool may draw the elongate tie tail through the cable tie head, to tightly bind the elongate articles into a bundle. After the tie is tensioned around the bundle, the excess length of the tie tail which extends out of the head portion is then severed by the tool close to the head. Ties are often applied in high volumes and to precise tensions. 
         [0004]    Many presently available tie tensioning and severing tools require an operator to apply an excessive force on their triggers which leads tool operator fatigue after only a relatively small number of cables ties have been installed by the operator. Other electric or pneumatic tie tensioning and severing tools may apply uneven force during tensioning. Moreover, the gripping mechanism of known devices may slip or unevenly distribute force during tensioning, thereby causing the tie tail to break or tear during tensioning. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention is directed to a hand-held tensioning and severing tool which avoids the aforementioned shortcomings. 
         [0006]    In accordance with an important aspect of the present invention, an improved hand-held tie tool is provided which includes a gripping mechanism wherein the pawl hood is provided with an aggressive texture pattern on its surface that contacts the tie tail. The texture pattern imparts an additional gripping quality to the pawl hood and more evenly distributes force on the tie tail during tensioning. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a perspective view of a cable tie tensioning and cut-off tool according to the present invention. 
           [0008]      FIG. 2  is a left side view of the tool illustrated in  FIG. 1 . 
           [0009]      FIG. 3  is a top view of the tool illustrated in  FIGS. 1 and 2 . 
           [0010]      FIG. 4  is a view similar to that of FIG.  2 , but with a portion of the housing removed with cable tie and bundle shown in phantom. 
           [0011]      FIG. 5  is an enlarged fragmentary view of the tool illustrated in  FIG. 4  and showing a pawl link with shroud according to the present invention. 
           [0012]      FIG. 6  is a perspective view of a pawl link with shroud according to the present invention. 
           [0013]      FIG. 7  is another perspective view of the pawl link with shroud illustrated in  FIG. 6 . 
           [0014]      FIG. 8  is a view similar to that of  FIG. 5 , but showing a tie tail in phantom engaged between a pawl and textured pawl shroud. 
           [0015]      FIG. 9A  is a partial sectional view taken along line  9 A of  FIG. 7  and showing a pattern of a textured pawl shroud. 
           [0016]      FIG. 9B  is a partial sectional view taken along line  9 B of  FIG. 7 , similar to that of  FIG. 9A , and showing another pattern of a textured pawl shroud. 
           [0017]      FIG. 9C  is a cross sectional view of  FIG. 9A  and taken along line  9 C- 9 C thereof. 
           [0018]      FIG. 10A  is a partial sectional view taken along line  10 A of  FIG. 7 , similar to that of  FIGS. 9A and 9B , and showing another pattern of a textured pawl shroud. 
           [0019]      FIG. 10B  is a partial sectional view taken along line  10 B of  FIG. 7 , similar to that of  FIGS. 9A, 9B and 10A , and showing another pattern of a textured pawl shroud. 
           [0020]      FIG. 10C  is a cross sectional view of  FIG. 10A  and taken along line  10 C- 10 C thereof. 
           [0021]      FIG. 11A  is a partial sectional view taken along line  11 A of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, and 10B , and showing another pattern of a textured pawl shroud. 
           [0022]      FIG. 11B  is a partial sectional view taken along line  11 B of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A and 10B , and showing another pattern of a textured pawl shroud. 
           [0023]      FIG. 11C  is a cross sectional view of  FIG. 11A  and taken along line  11 C- 11 C thereof. 
           [0024]      FIG. 12A  is a partial sectional view taken along line  12 A of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, and 11B , and showing another pattern of a textured pawl shroud. 
           [0025]      FIG. 12B  is a partial sectional view taken along line  12 B of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, and 11B , and showing another pattern of a textured pawl shroud. 
           [0026]      FIG. 12C  is a cross sectional view of  FIG. 12A  and taken along line  12 C- 12 C thereof. 
           [0027]      FIG. 13A  is a partial sectional view taken along line  13 A of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, and 12B , and showing another pattern of a textured pawl shroud. 
           [0028]      FIG. 13B  is a partial sectional view taken along line  13 B of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, and 12B , and showing another pattern of a textured pawl shroud. 
           [0029]      FIG. 13C  is a cross sectional view of  FIG. 13A  and taken along line  13 C- 13 C thereof. 
           [0030]      FIG. 14A  is a partial sectional view taken along line  14 A of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, 12B, 13A and 13B , and showing another pattern of a textured pawl shroud. 
           [0031]      FIG. 14B  is a partial sectional view taken along line  14 B of  FIG. 7 , similar to that of FIGS.  9 A,  9 B,  10 A,  10 B,  11 A,  11 B,  12 A,  12 B,  13 A and  13 B, and showing another pattern of a textured pawl shroud. 
           [0032]      FIG. 14C  is a cross sectional view of  FIG. 14A  and taken along line  14 C- 14 C thereof. 
           [0033]      FIG. 15A  is a partial sectional view taken along line  15 A of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, 12B, 13A, 13B, 14A and 14B , and showing another pattern of a textured pawl shroud. 
           [0034]      FIG. 15B  is a partial sectional view taken along line  15 B of  FIG. 7 , similar to that of  FIGS. 9A, 9B, 10A, 10B, 11A, 11B, 12A, 12B, 13A, 13B, 14A and 14B , and showing another pattern of a textured pawl shroud. 
           [0035]      FIG. 15C  is a cross sectional view of  FIG. 15A  and taken along line  15 C- 15 C thereof. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0036]    Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
         [0037]    Referring now to the drawings and in particular to  FIGS. 1 and 2 , an embodiment of a cable tie tensioning and cut-off tool  10  incorporating the principles of the present invention is shown. As illustrated, the tool  10  preferably includes a housing  12  in the shape of a pistol or gun and having a handle or grip portion  14 , a barrel portion  16 , and a trigger  18 . The trigger  18  is located forwardly of the grip  14  and under the barrel portion  16  where it fits naturally in the hand of a user (not shown). While a manually operated tool  190  is shown in the Figures, it is to be understood that the present invention is applicable to both electrically and pneumatically operable tools  10  as well. The tool  10  is typically used to install cable ties  20  (seen in phantom in  FIG. 4 ) around elongate bundles  22 , such as wire cable or the like. The tool  10  may be used to install cable ties  20  in a wide variety of environments and applications. For example, the tool  10  may be used to bundle together a plurality of elongate wires, cables, or other elongate articles  22 , as is shown in the Figures, or it may be used in conjunction with cable ties  20  in other applications, such as to secure elongate articles  22  to rigid structures or to clamp hoses (not shown), by way of non-limiting examples. As illustrated and will be discussed, a tie  20  for use with the present tool  10  preferably includes a head portion  24  and a tie tail portion  26 . In use, a pawl  30  in conjunction with a pawl shroud  200 , grips the tail portion  26  of the tie  20  and pawl link  28 A,  28 B pulls the tail portion  26  through the head portion  24  until a predetermined tension is achieved around an elongate article  22 . A blade member  160  in the barrel  16  of the tool  10  cuts off the excess tail portion  26  adjacent the head  24 . 
         [0038]    With particular attention to  FIGS. 4 and 5 , part of one housing  12  sidewall has been cut away to show the opposite housing  12  sidewall and the internal parts and mechanism of the present tool  10 . The tool  10  generally contains a reciprocating tension mechanism, such as the pawl links  28 A,  28 B shown, located in the barrel portion  16  of the tool  10  and activated by the trigger  18 . AS mentioned, the pawl link  28 A,  28 B is associated with a gripping mechanism, such as the tie-gripping pawl  30  shown, which in combination with a pawl shroud  200  cooperates to grip the tail portion  26  of a tie  20 , as will be discussed. 
         [0039]    With attention to  FIGS. 6 and 7 , pawl link  28 B may be seen to further include a pawl shroud  200  having a top surface  202  and a bottom surface  204 , wherein the bottom surface  204  is provided with a predetermined texture having a high coefficient of friction. The textured bottom surface  204  provides additional gripping capability than in previous known designs. The textured bottom surface  204  provides a more even distribution of force on the tail  26  during tensioning to thereby reduce tail  26  breakage. Moreover, the textured bottom surface  204  further allows ties  20  to be more uniformly tensioned without undue stretching. The pawl links  28 A,  28 B further include a gripping mechanism therebetween, such as the tie-gripping toothed pawl  30  shown, for gripping the tail portion  26  of a tie  20 . 
         [0040]    In operation, and as further seen in  FIG. 8 , the tail portion  26  is gripped between the toothed pawl  30  and the pawl shroud lower surface  204 , and pulled rearwardly to a predetermined tension. Upon reaching the predetermined tension, a cutoff mechanism, such as the illustrated cutter link  118 , also located at the forward end of the barrel portion  16 , activates to cause a blade member  160  to cut off the tie tail  26  closely adjacent the head portion  24 . The pawl shroud  200  has a bottom surface  204  that provides an increased coefficient of friction by way of a predetermined texture, as will be discussed in detail. 
         [0041]    As mentioned, the present device provides improved gripping of the tie tail  26  during tensioning and cut off, such that more uniform tensioning of the tie  20  is achieved. Specifically, the textured pawl shroud  200  allows better grip on the tie tail  26  during tensioning and therefore less distortion and stretching of the tail  26  occurs during tensioning. The effect reduces breakage of the tile tail  26  since the tensioning force is more evenly distributed. A pawl shroud  200  for use in the present invention may be made of steel, plastic or other suitable material. The views of  FIGS. 5-8  illustrate the pawl shroud  200  is seen as having a bottom surface  204  configured to increase the coefficient of friction over a partial area or substantially the entire surface. A predetermined portion, or substantially all, of the bottom surface  204  may be modified to provide the desired coefficient of friction. For example, the surface  204  may include an aggregate or other modifications to intentionally increase its friction characteristics, as will be discussed. 
         [0042]    With particular attention to  FIGS. 9A-15C , various textured bottom surfaces  204  of a pawl shroud  200  according to the present invention may be seen. With reference particularly to  FIGS. 9A-9C , the predetermined texture pattern of the bottom surface  204  of the pawl shroud  200  may be seen as a plurality of recessed knurls  206 . As shown, the knurls  206  may cover a portion of the bottom surface  204 , as is illustrated in  FIG. 9A , or substantially the entire bottom surface  204 , as seen in  FIG. 9B .  FIG. 9C  is a cross section view illustrating recessed knurls  206  as applied to the bottom surface  204 .  FIGS. 10A-10C  illustrate a pattern of knurls  206 A similar to that of  FIGS. 9A-9C , but showing knurls  206 A having a larger size as compared to those in  FIGS. 9A-9C . In both instances, the knurls  206 ,  206 A operate in conjunction with the toothed pawl  30  to provide increased resistance to slippage, due to an increased coefficient of friction, of the tie tail  26  during tensioning. The addition of the recessed knurls  206 ,  206 A on the bottom surface  204  of the pawl shroud  200  improves grip on the tie tail  26 . Moreover, since the tensioning forces act on a greater portion of the tie tail  26  as is contacted by the bottom surface  204 , rather than merely against a tooth  32  of the pawl  30 , an added advantage is a reduction of tie  20  breakage during installation and tensioning. The tensioning forces are dispersed more evenly against the tie tail  26  as compared to known arrangements. This feature provides the further benefit of extending longevity of the pawl  30 , since the upstanding pawl teeth  32  are not required to be maintained in as sharp a condition as when used without the present pawl shroud  200 . Moreover, the required hold force is reduced, thereby lessening wear on other cooperating components of the tool  10 . 
         [0043]      FIGS. 11A-11C  illustrate another texture pattern for use on the bottom surface  204  of a pawl shroud  200 . As shown, the bottom surface  204  may include a predetermined texture pattern having a plurality of elevated ridges  208 . As is shown, the elevated ridges  208  may cover a portion of the bottom surface  204 , as is shown in  FIG. 11A , or substantially the entire bottom surface  204 , as shown in  FIG. 11B .  FIG. 11C  is a cross section view illustrating the elevated ridges  208  as applied to the bottom surface  204 . As with the previously described recessed knurls  206 ,  206 A, the elevated ridges  208  operate in conjunction with the toothed pawl  30  to provide increased resistance to slippage of the tie tail  26  during tensioning and to improve grip on the tie tail  26 . Improved grip on the tie tail  26  reduces tie  20  breakage during installation and tensioning and further promotes longevity of the pawl  30 . Moreover, the required hold force is reduced, thereby lessening wear on other cooperating components of the tool  10 . 
         [0044]      FIGS. 12A-12C  illustrate another texture pattern for use on the bottom surface  204  of a pawl shroud  200 . In these views, the bottom surface  204  may include a predetermined texture pattern having a plurality of incised divots  210 . As shown, and as in previous embodiments, the incised divots  210  may cover a portion of the bottom surface  204 , as is shown in  FIG. 12A , or substantially the entire bottom surface  204 , as shown in  FIG. 12B .  FIG. 12C  is a cross section view illustrating the incised divots  210  as applied to the bottom surface  204 . As with the previously described recessed knurls  206 ,  206 A, and elevated ridges  208 , the incised divots  210  operate in conjunction with the toothed pawl  30  to resist slippage of the tie tail  26  during tensioning and to improve grip of the tie tail  26 . Improved grip on the tie tail  26  reduces tie  20  breakage during installation and tensioning, promotes longevity of the pawl  30 , and lessens wear on other cooperating components of the tool  10 . 
         [0045]      FIGS. 13A-13C  illustrate another texture pattern for use on the bottom surface  204  of a pawl shroud  200 . As shown, the bottom surface  204  may include a predetermined texture pattern having a plurality of incised grooves  212 . As shown, and as in previous embodiments, the incised grooves  212  may cover a portion of the bottom surface  204 , as is shown in  FIG. 13A , or substantially the entire bottom surface  204 , as shown in  FIG. 13B .  FIG. 13C  is a cross section view illustrating the incised grooves  212  as applied to the bottom surface  204 . As with the previously described recessed knurls  206 ,  206 A, elevated ridges  208 , and incised divots  210 , the incised grooves  212  operate in conjunction with the toothed pawl  30  to resist slippage of the tie tail  26  during tensioning and to improve grip on the tie tail  26 . Improved grip on the tie tail  26  reduces tie  20  breakage during installation and tensioning, promotes longevity of the pawl  30 , and lessens wear on other cooperating components of the tool  10 . 
         [0046]      FIGS. 14A-14C  illustrate another texture pattern for use on the bottom surface  204  of a pawl shroud  200 . As shown, the bottom surface  204  may include a predetermined textured pattern comprised of an aggregate  216 . The aggregate  216  may be attached to the bottom surface  204  in any known manner, such as by adhesive (not shown). As illustrated, and as in previous embodiments, the aggregate  216  may cover a portion of the bottom surface  204 , as is shown in  FIG. 14A , or substantially the entire bottom surface  204 , as shown in  FIG. 14B .  FIG. 14C  is a cross section view illustrating the aggregate  216  as applied to the bottom surface  204 . As with the previously described recessed knurls  206 ,  206 A, elevated ridges  208 , incised divots  210 , and incised grooves  212 , the aggregate  216  operates in conjunction with the toothed pawl  30  to resist slippage of the tie tail  26  during tensioning and to improve grip on the tie tail  26 . 
         [0047]      FIGS. 15A-15C  illustrate another texture pattern for use on the bottom surface  204  of a pawl shroud  200 . As shown, the bottom surface  204  may include a predetermined textured pattern comprised of a plurality of raised knurls  218 . As shown, the raised knurls  218  may cover a portion of the bottom surface  204 , as is shown in  FIG. 15A , or substantially the entire bottom surface  204 , as shown in  FIG. 15B .  FIG. 15C  is a cross section view illustrating the raised knurls  218  as applied to the bottom surface  204 . As with the previously described recessed knurls  206 ,  206 A, elevated ridges  208 , incised divots  210 , and incised grooves  212 , the raised knurls  218  operate in conjunction with the toothed pawl  30  to provide increased resistance to slippage of the tie tail  26  during tensioning and to improve grip on the tie tail  26 . 
         [0048]    It is to be understood that while various texture patterns having a high coefficient of friction illustrated are disclosed herein, the present invention is not limited, and may include other knurling patterns, laser etching, abrasion, cutting, stippling or other patterns able to impart a higher coefficient of friction to the pawl shroud, without limitation. 
         [0049]    The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention which is defined by the claims.