Abstract:
A ratchet includes a knurled or longitudinally ridged roller for engagement by webbing. A pawl includes a lobe having knurling or ridges formed thereon on its curved surface for contacting the webbing and urging the webbing toward the roller. Upon applying a pulling force on the free end of the webbing it causes the roller to rotate and the pawl to rotate away from the roller. Translation of the webbing in the opposite direction causes the pawl to rotate toward the roller and compress the webbing between the lobe of the pawl and the roller. The knurling on the surfaces of the roller and the lobe prevent sliding movement of the webbing therepast. Applying a downward force on an extension of the pawl will cause rotation of the lobe out of contact with the webbing and permit translation of the webbing in either direction.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to a provisional patent application entitled “550 CORD P-NUT AND CAMMING UNITS”, assigned Ser. No. 61/680,056 and filed Aug. 6, 2012, which describes an invention made by the present inventor. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to ratchets and, more particularly, to ratchets having a pawl for securing webbing against a roller. 
         [0004]    2. Description of Related Prior Art 
         [0005]    Ratchets of various types have been in existence for decades. The most common types of ratchets include a spool about which webbing or a strap is wrapped. A pivotable lever in engagement with sprockets attached to the spool can cause rotation of the spool in a first direction to wrap the webbing about the spool. A pawl or sliding member engages the sprocket to prevent rotation in the second direction whereby unwrapping of the webbing is precluded except upon release of the pawl or sliding member from the sprocket. 
         [0006]    A second type of ratchet is used in conjunction with a rope. It includes a spool formed by a pair of facing discs having protrusions on the facing surfaces of the discs to frictionally engage the rope. The rope is wrapped about one-half of the spool. By pulling on the free end of the rope, the spool is caused to turn in one direction to provide tension to the other end of the rope. Slippage of the other end of the rope in the other direction is precluded by the frictional engagement between the rope and the protrusions of the faces of the disc. A spring-loaded pawl precludes rotation of the spool in the other direction. By pivoting the pawl out of engagement with the spool, the rope is free to cause rotation of the spool in either direction. U.S. Pat. Nos. 6,068,242, 6,092,791, and Des. 362,614 are representative of ratchets of this type and are incorporated herein by reference. 
         [0007]    The major distinction between these two types of spools may be categorized as follows. In the first type, slippage of the webbing from about a rotatably locked spool is prevented by the friction attendant layers of wrapped webbing; in some embodiments, the free end of the webbing extends through a diametrically oriented slot in the spool. 
         [0008]    In the second type of ratchet, the friction between the rope and the protrusions on opposing faces of the discs forming the spool create sufficient friction and compression of the rope therebetween to preclude slippage. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is directed to a ratchet for use with webbing. A roller, in the nature of a cylinder, includes either a knurled surface or ridges on the surface for frictionally engaging the webbing partially wrapped thereabout and extending into and out of the body of the ratchet. A pawl includes a corresponding knurled surface or ridges on the surface and is spring biased against the roller. Exerting a tension force on the webbing to be tensioned and exiting from the ratchet will cause the pawl to be pivoted toward the roller and firmly engage the webbing between the roller and the pawl. Such engagement will preclude translation of the webbing due to its frictional engagement with the pawl. Upon pulling the free end of the webbing, the pawl will be pivotally urged away from the roller and the frictional engagement of the webbing with the roller and the pawl will be released and permit the roller to rotate in accordance with the force exerted on the free end of the webbing. A hook or other mechanism may be attached to the ratchet to anchor the ratchet or to engage a member to be drawn toward the ratchet. 
         [0010]    It is therefore a primary object of the present invention to provide a ratchet for use with webbing. 
         [0011]    Another object of the present invention is to provide a low parts count ratchet. 
         [0012]    Still another object of the present invention is to provide a ratchet having essentially only two moving parts for securing webbing. 
         [0013]    Yet another object of the present invention is to provide a ratchet having a pawl for locking webbing against a freely rotatable roller. 
         [0014]    A further object of the present invention is to provide a ratchet with knurled surfaces on a roller and on a pawl. 
         [0015]    A still further object of the present invention is to provide a ratchet having ridges on the surfaces of a roller and a pawl. 
         [0016]    A yet further object of the present invention is to provide a method for applying tension to a length of webbing. 
         [0017]    These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]    The present invention will be described with greater specificity and clarity with reference to the following drawings, in which: 
           [0019]      FIG. 1  is an isometric view of a first embodiment of the present invention; 
           [0020]      FIG. 2  is a side view of the present invention shown in  FIG. 1 ; 
           [0021]      FIG. 3  is an exploded view of the major components of the first embodiment; 
           [0022]      FIG. 4  is an exploded view; 
           [0023]      FIG. 5  illustrates a spring coupled with a pawl; 
           [0024]      FIG. 6  is an exploded view; 
           [0025]      FIG. 7  is a partial cross-sectional view of the first embodiment; 
           [0026]      FIG. 8  is an isometric view illustrating a second embodiment of the present invention; 
           [0027]      FIG. 9  is an isometric view illustrating straps attachable and attached to the second embodiment; 
           [0028]      FIG. 10  is an exploded view of the major components of the second embodiment; 
           [0029]      FIG. 11  is an exploded view; 
           [0030]      FIG. 12  is a partial cross-sectional view of the second embodiment; 
           [0031]      FIG. 13  is an isometric view of a third embodiment of the present invention; 
           [0032]      FIG. 14  is an exploded view of the major components of the third embodiment; and 
           [0033]      FIG. 15  is a partial cross-sectional view of the third embodiment. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0034]    Referring to  FIG. 1 , there is a first embodiment of a ratchet  10  showing a finger operated pawl  12  cooperating with a webbing supporting roller  14 . Sidewalls  16  and  18  support a plurality of bosses extending from each sidewall. Bosses  20  and  22  may support a loop of a webbing attached to an anchor or the like. Bosses  24  and  26  may be used to support a further webbing assembly, as will be described in further detail below. As shown in  FIG. 2 , screws  28 , and  32  extend through the bosses attached to sidewall  16  into threaded engagement with corresponding bosses extending from sidewall  18 . A passageway  34  disposed in sidewall  16  supports a stud extending from pawl  12 . 
         [0035]    Referring to  FIG. 3 , further details of the components of ratchet  10  will be described. Sidewalls  16  and  18  further support bosses  36 ,  38 , respectively, which bosses rotatably support roller  14 . Roller  14  includes knurling  40  to minimize slippage of a length of webbing partially wrapped thereabout; alternatively, it may includes a plurality of longitudinally aligned ridges to assist in gripping the webbing. Pawl  12 , as also shown in  FIG. 5 , includes a lobe  42  for engaging roller  14  with greater or lesser force as a function of the rotational position of the pawl. Stud  44  is supported within passageway  34  of sidewall  16  to accommodate incremental rotation of the pawl. Knurling  40  may be replaced by a plurality of longitudinally aligned ridges to more firmly engage webbing in contact therewith (note for example the ridges on the pawl shown in  FIG. 7 ). A spring  46  includes an arm  48  in penetrable engagement with passageway  50  shown in sidewall  16  to anchor the spring. It is noted that coil  52  is disposed about stud  44 . Arm  54  of the coil spring bears against ledge  56  of pawl  12 . Thereby, the spring rotationally biases pawl  12  against roller  14  to secure webbing therebetween. 
         [0036]      FIG. 4  is a top exploded view of ratchet  10 . Referring jointly to  FIGS. 3 and 4 , a bolt or screw  58  extends through a passageway  60  in boss  36  into threaded engagement with a passageway  62  in boss  38 . A bolt or screw  64  extends through a passageway  66  in boss  24  into threaded engagement with passageway  68  in boss  26 . A bolt or screw  70  extends through passageway  72  in boss  20  into threaded engagement with passageway  74  in boss  22 . As noted above, roller  14  is rotatably supported upon bosses  36  and  38 . Pawl  12  is pivotally supported upon stud  44  engaging passageway  34  in sidewall  16 . A further stud  76  is pivotally supported in passageway  78  in sidewall  18 . 
         [0037]      FIG. 6  is an exploded view illustrating spring  46  supported upon stud  44  with arm  54  in engagement with ledge  56 . Knurling  43  is disposed upon lobe  42  of pawl  12  and similar knurling  40  is disposed upon roller  14 . 
         [0038]    Referring to  FIG. 7 , there is depicted the function of ratchet  10  in cooperation with a length of webbing  80 . The webbing extends partially about roller  14  in frictional engagement with knurling  40  disposed upon the roller. The arrow in combination with the letter F identifies the free end of webbing  80  which is pulled to cause tension on the other length of webbing, depicted by the arrow and the letter T. Thereby, the webbing can be tensioned. Pawl  12  includes lobe  42  configured such that upon clockwise movement of the pawl about stud  44 , surface  82  of the lobe bears against webbing  80 . As depicted in previous figures, the lobe may include knurling or the lobe may include a plurality of longitudinally aligned ridges  84 , as depicted in  FIG. 7 . It may be noted that spring  46  biases pawl  12  in the clockwise direction, as shown in  FIG. 7 . Thereby, frictional engagement of webbing  80  is created by both roller  14  and the lobe of pawl  12  to prevent slippage of the webbing. 
         [0039]    Upon counterclockwise movement of the pawl by pressing arm extension  86  surface  82  of lobe  42  becomes displaced from adjacent webbing  80  due to the shape of lobe  42  and the webbing becomes no longer locked within ratchet  10 . 
         [0040]    One purpose for bosses  24 ,  26  joined with one another is that of supporting webbing having dual loops. As shown in  FIG. 12 , webbing assembly  90  includes loops  92  and  94 . A further loop  96  extends into the ratchet and wraps about bosses  24 ,  26  shown in  FIG. 3 . Thereby, loop  92  may be engaged with anchoring webbing extending from bosses  20 ,  22  and doubled back upon itself to loop  92 . Similarly, webbing identified with the letter T in  FIG. 7  may be looped about an item of interest and doubled back upon itself into engagement with loop  94 . Thereby, the tension force that can be applied by ratchet  10  is essentially doubled. 
         [0041]    Referring to  FIGS. 8 and 9 , there is shown a second embodiment of the ratchet designated as ratchet  100 . The ratchet includes a pair of sidewalls  102 ,  104  supporting a pawl  106  and a roller  108 . A strap  110  extends from ratchet  100  to an anchor or the like. Alternatively, the strap may be doubled about an anchor and connected to loop  112 . Webbing  114  is connected to an item of interest and serves as the tensioning member to apply tension to the item of interest and draw it toward an anchor. Webbing  114  extends about roller  108  and provides a free end  116 . Webbing  114  may extend about an element of an item of interest and folded back upon itself for connection to loop  118 . By folding strap  110  about itself and connecting it to loop  112 , the strength of the connection to an anchor is essentially doubled. Similarly, by folding webbing  114  about itself and connecting it to loop  118 , its strength is essentially doubled. As loop  112  and loop  118  are essentially connected to one another, as depicted in  FIG. 12 , essentially no additional force is imposed upon ratchet  100  since loop  96 , engaging bosses  144 ,  148  simply attaches webbing assembly  90  to the ratchet. 
         [0042]    Referring jointly to  FIGS. 10 and 11 , certain features internal to ratchet  100  will be described. A boss  120  extends from sidewall  104  and butts against boss  122  extending from sidewall  102 . A bolt or screw  124  extends through passageway  126  in boss  120  into threaded engagement with a corresponding passageway  128  in boss  122 . A bolt or screw  130  extends through passageway  132  in boss  134  extending from sidewall  102  into threaded engagement with passageway  136  in boss  138 . A further bolt or screw  140  extends through passageway  142  in boss  144  extending from sidewall  104  into threaded engagement with passageway  146  in boss  148 . Pawl  106  includes stud  150  secured within passageway  152  in sidewall  102  and a stud  154  secured within passageway  156  in sidewall  104 . Thereby, the pawl is pivotally supported intermediate sidewalls  102  and  104 . Roller  158  is rotatably supported upon bosses  120  and  122 . A spring  162  may be mounted on stud  154  and includes an arm  164  in engagement with passageway  166  in sidewall  104  to anchor that arm. A further arm  168  is in engagement with pawl  106  (as depicted in  FIG. 12 ) to bias the pawl in the clockwise direction, as shown in  FIG. 12 . As depicted, the surface of roller  158  may include knurling  160 . As depicted in  FIGS. 11 and 12 , knurling  176  is formed on lobe  172  of pawl  106  to frictionally engage with webbing  114 / 116 . 
         [0043]    As primarily depicted in  FIGS. 10 and 11 , a guide  170  is located intermediate sidewalls  102 ,  104  to guide free end  116  of webbing into ratchet  100  and about roller  158  and past lobe  172  of pawl  106  when the pawl is rotated in the counterclockwise direction by pressing on extension  174  of the pawl. Upon such insertion, the free end  116  of webbing  114  is pulled until webbing  114  is tightened to provide a degree of tension force (depicted by the letter T) on the webbing to secure the item of interest. Spring  162  urges rotation of pawl  106  in the clockwise direction. This brings knurling  160  disposed on lobe  172  into frictional engagement with webbing  114 . It may be noted that the tension force on webbing  114  will tend to draw the webbing against the knurling of the pawl to urge the pawl to rotate in a clockwise direction. Because of lobe  172 , such urged rotation will further force knurling  176  into contact with webbing  114  and the resulting compression of the webbing will cause it to further engage knurling  160  disposed on roller  158 . As discussed above, webbing assembly  90  may be used to double the force exerted on strap  110  engaged about an anchor and folded upon itself into engagement with loop  92 . Similarly, webbing  114  can be folded about itself and around an item of interest into engagement with loop  94 . As the opposing forces exerted on loops  92 ,  94  are accommodated by the webbing assembly itself, no force of any consequence is imposed upon ratchet  100 . 
         [0044]    Referring jointly to  FIGS. 13 ,  14  and  15 , a third embodiment of a ratchet  180  is illustrated. Ratchet  180  is formed by sidewalls  182 ,  184  supporting a pawl  186  and various other elements to be described below. A boss  188  extends from sidewall  182  and includes a passageway  190 . It mates with a boss  192  extending from sidewall  184 . A bolt or screw  194  extends through passageway  190  into threaded engagement with passageway  196  in boss  192 . A boss  198  having a passageway  200  extending therethrough mates with a boss extending from sidewall  184 . A bolt or screw  204  extends through passageway  200  into threaded engagement with passageway  206  in boss  202 . A boss  208  having a passageway  210  extends from sidewall  182  to mate with a boss  212  extending from sidewall  184 . A bolt or screw  214  extends through passageway  210  into threaded engagement with passageway  216  in boss  212 . A boss  218  having a passageway  220  extends from sidewall  182  and mates with a boss  222  extending from sidewall  184 . A bolt or screw  224  extends through passageway  220  into threaded engagement with a passageway  226  in boss  222 . Thereby, the sidewalls are secured to one another and support for various components within the ratchet is provided. 
         [0045]    Pawl  186  includes a stud  228  for engagement with a passageway  230  in sidewall  184 . A similar stud  232  engages passageway  234  in sidewall  182 . Thereby, pivotal movement of the pawl can occur about the axis of studs  228  and  232 . A spring  234  is mounted on stud  232 . Arm  236  of the spring is anchored in hole or passageway  237  in sidewall  182 . Arm  238  of the spring engages a hole or passageway  239  in the pawl, as particularly shown in  FIG. 15 . Thereby, the pawl is biased in the clockwise direction, as shown in  FIG. 15 . Bosses  188 ,  192  support roller  235 . Roller  235  shown in  FIG. 14  is depicted to include knurling  264 . However, it may include ridges instead, as shown for roller  240 . Boss  198  and its mating boss extending from sidewall  184  supports roller  240 . This roller may include a plurality of longitudinally aligned ridges  242 . Each of these ridges includes a radially aligned surface  244 . Pawl  186  includes a plurality of teeth or ridges  243  for engagement with ridges  242  of roller  240 . 
         [0046]    Webbing  246  is inserted into ratchet  180  either over bosses  188  and  192  or roller  235  and downwardly therefrom. Upon such downward movement, the webbing is guided about roller  240  by guide  248 . By depressing extension  249  of pawl  186 , the pawl is pivoted out of engagement with roller  240  to provide passage of the webbing between this roller and ridges  242  of the pawl. Webbing  246  is drawn out of the ratchet, as depicted. The free end of the webbing, as depicted by the letter F and accompanying arrow, is pulled until the length of webbing depicted by the letter T and the accompanying arrow has been tightened with respect to the item of interest attached to the webbing. Upon a continuing pulling force on webbing  246 , as depicted by the accompanying arrow, the webbing is drawn into the ratchet, as depicted by the arrow and letter T. Reverse translation of the webbing is precluded by ridges  242  of the pawl being biased toward the webbing and the mechanical interaction of these ridges to prevent counterclockwise rotation of roller  240 . 
         [0047]    Webbing  250  includes a loop  252  partially encircling bosses  208  and  212 . This webbing may be directly connected to an anchor or it may extend around the anchor and folded upon itself for connection to loop  254 . Similarly, the length of webbing identified by the letter T may extend about the item of interest and folded upon itself for engagement with loop  256 . As loops  254  and  256  are connected with one another, the tension therebetween is primarily carried by webbing  258 . A further loop  260  extends into ratchet  180  and receives support from bosses  218 ,  222 . Because the loads imposed upon loops  254 ,  256  are accommodated by webbing  258 , essentially no load is placed upon bosses  218 ,  222  and these bosses serve primarily a function of supporting webbing  258  adjacent ratchet  180 .