Abstract:
A hammer has a claw assembly that is moveable relative to the head of the hammer so as to improve leverage and range of prying for nail removal. The ratcheting mechanism may be automatic or manual.

Description:
RELATED APPLICATION 
       [0001]    This application is a non-provisional and claims the benefit of priority of U.S. Provisional Application No. 61/739,940 filed Dec. 20, 2012, the entire contents of which are incorporated herein and made a part hereof. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to claw hammers, and, more particularly to a claw hammer with a claw that is moveable relative to the head of the hammer so as to improve leverage and range of prying for nail removal. 
       BACKGROUND 
       [0003]    As is well known, a conventional claw hammer is a tool primarily used for pounding nails into or extracting nails from some other object. Generally, a claw hammer is associated with woodworking but is not limited to use with wood products. 
         [0004]    A conventional claw hammer  10  is illustrated in  FIG. 1 . From a profile, it roughly resembles the letter “T”. The handle  15  is the long vertical part. The head assembly  20  includes a striking head  25  and a curved two-prong claw  30  opposite the striking head. The claw  30  curves downward (i.e., towards the handle) and splits in the middle forming a “V” shape gap  35 . The claw increases in thickness from the free end to the intersection with the handle  15 . This gap  35  is the part of the claw  30  of the hammer  10  that is commonly used for extracting nails from wood. The curved claw  30  in conjunction with the handle  15  is used to gain leverage when extracting a nail. 
         [0005]    The curvature and length of the claw  30  varies among hammers. By way of example, the claw of a framing hammer may feature less curvature than the claw curvature of a finishing hammer and therefore does not have as much leverage for removing nails. While claws are useful for fully extracting short nails in one fluid motion, long nails pose challenges. A claw may not have sufficient length and range of motion to fully extract the nail. The claw may be adequate to partially remove the nail. A user must then struggle to extract the remaining embedded portion of the nail, such as by applying another tool, e.g., pliers, and considerable pulling force or by applying a board, such as a 2×4, to raise the height of the fulcrum point. Although a hammer could be provided with an extremely long curved claw sufficient to extract even the longest nail, such a hammer would be extremely cumbersome to wield. 
         [0006]    The invention is directed to overcoming one or more of the problems and solving one or more of the needs as set forth above. 
       SUMMARY OF THE INVENTION 
       [0007]    To solve one or more of the problems set forth above, in an exemplary implementation of the invention, a hammer includes a linearly adjustable ratcheting claw. The claw assembly includes a claw with a v-shaped groove for engaging a nail. The claw assembly is movable linearly relative to the striking head of the hammer. A channel is configured to receive and glide along an engaging portion of the handle. A ratcheting mechanism causes a pawl to engage and disengage a rack of spaced apart teeth. The pawl and rack regulate linear movement of the claw assembly. A spring compartment in the handle contains a compression spring that urges the claw assembly towards its topmost (extended) position. A nail head lever is attached to the concave side of the claw. The lever extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw, the head of the nail may bear against the lever. The lever may be attached with a pivot pin and biased to pivot towards an abutting nail head. The lever may also be operably coupled to a linkage coupled to a pawl. The linkage may advance the pawl to allow retraction of the claw assembly when the lever is pushed by a nail. While the pawl locks the claw assembly in place, a permanent magnet at the apex of the handle helps to secure the claw assembly. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The foregoing and other aspects, objects, features and advantages of the invention will become better understood with reference to the following description, appended claims, and accompanying drawings, where: 
           [0009]      FIG. 1  provides profile and perspective views that conceptually illustrate a prior art conventional claw hammer; and 
           [0010]      FIG. 2  provides a perspective view of an exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0011]      FIG. 3  provides a perspective view of an exemplary embodiment of a portion of a hammer, with the linearly adjustable ratcheting claw removed, according to principles of the invention. 
           [0012]      FIG. 4  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0013]      FIG. 5  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0014]      FIG. 6  provides a perspective view of an exemplary embodiment of a claw assembly for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0015]      FIG. 7  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0016]      FIG. 8  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw in a retracted position according to principles of the invention. 
           [0017]      FIG. 9  schematically illustrates an exemplary embodiment of a ratcheting rack and pawl assembly for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
           [0018]      FIG. 10  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw in a retracted position according to principles of the invention. 
           [0019]      FIG. 11  provides a perspective view of an exemplary embodiment of a claw assembly for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. 
       
    
    
       [0020]    Those skilled in the art will appreciate that the figures are not intended to be drawn to any particular scale; nor are the figures intended to illustrate every embodiment of the invention. The invention is not limited to the exemplary embodiments depicted in the figures or the specific components, configurations, shapes, relative sizes, ornamental aspects or proportions as shown in the figures. 
       DETAILED DESCRIPTION 
       [0021]    Referring now to  FIG. 2 , a perspective view of an exemplary embodiment of a hammer  100  with a linearly adjustable ratcheting claw assembly  160  according to principles of the invention is shown. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail. The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. A channel  141  is configured to receive and glide along an engaging portion of the handle. A ratcheting mechanism, which includes a manual switch  140 , causes a pawl to engage and disengage a rack  125  of spaced apart teeth. The pawl and rack regulate linear movement of the claw assembly  160 . 
         [0022]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as shown in  FIG. 2 . The spring may be a coil, leaf or other type of biasing means that resists compression. A removable cover  135  closes the opening of the spring compartment  130 . The cover  135  fits flush against the opening so as to avoid interference with up and down motion of the claw assembly  160 . 
         [0023]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin and biased to pivot towards an abutting nail head. The lever  145  may also be operably coupled to a linkage coupled to a pawl. The linkage may advance the pawl to allow retraction of the claw assembly  160  when the lever  145  is pivoted by an advancing nail. 
         [0024]    A permanent magnet  165  is attached at the apex of the handle  110 . The magnet  165  is stationary. The claw assembly  160  is comprised of a material to which the magnet  165  is magnetically attracted (e.g., a ferrous material). When the claw assembly  160  is in the fully raised (i.e., topmost) position as shown in  FIG. 2 , the magnet  165  helps securely hold the claw assembly  160 . Rattling, jostling and unintended movement of the claw assembly  160  are alleviated by the magnet  165 . 
         [0025]      FIG. 3  provides a perspective view of an exemplary embodiment of a handle and striking portion of a hammer  100 , with the linearly adjustable ratcheting claw removed, according to principles of the invention. The claw assembly abuts side  120  and is movable linearly relative to the striking head  105  of the hammer. Channels  115  are provided to receive flanged ends (i.e., rails) of a channel of the claw assembly, which glides along an engaging portion of the handle. A rack  125  of spaced apart teeth for the ratcheting action. Notice that the rack is positioned differently than in the embodiment of  FIG. 2 . The particular location of the rack is not important so long as it enables ratcheting control of linear movement of the claw assembly. 
         [0026]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as discussed above in relation to  FIG. 2 . The spring may be a coil, leaf or other type of biasing means that resists compression. 
         [0027]    Referring now to  FIG. 4 , a perspective view of another exemplary embodiment of a hammer  100  with a linearly adjustable ratcheting claw assembly  160  according to principles of the invention is shown. As with the embodiment described above, the claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail. The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. A channel of the claw assembly with flanged ends is configured to receive and glide along an engaging portion of the handle. The flanged ends slide within channels  132  in the handle  110 . A ratcheting mechanism, which includes a manual switch  140  and a cantilevered support  142 , causes a pawl to engage and disengage a rack of spaced apart teeth. The pawl and rack regulate linear movement of the claw assembly  160 . 
         [0028]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as shown in  FIG. 4 . The spring may be a coil, leaf or other type of biasing means that resists compression. 
         [0029]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail  152  may bear against the lever  145 . The lever  145  may be attached with a pivot pin and biased to pivot towards the abutting nail head. The lever  145  may also be operably coupled to a linkage coupled to a pawl. The linkage may advance the pawl to allow retraction of the claw assembly  160  when the lever  145  is pivoted by an advancing nail. 
         [0030]    A permanent magnet  165  is attached at the apex of the handle  110 . The magnet  165  is stationary. The claw assembly  160  is comprised of a material to which the magnet  165  is magnetically attracted (e.g., a ferrous material). When the claw assembly  160  is in the fully raised (i.e., topmost) position as shown in  FIG. 4 , the magnet  165  helps securely hold the claw assembly  160 . Rattling, jostling and unintended movement of the claw assembly  160  are alleviated by the magnet  165 . 
         [0031]      FIG. 5  provides a perspective view of another exemplary embodiment of a hammer  100  with a linearly adjustable ratcheting claw assembly  160  according to principles of the invention. Certain portions of the hammer are shown transparent, to conceptually illustrate components that would otherwise be hidden by the solid structures. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail  152 . The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. A flanged channel is configured to engage and glide in channels  132  along an engaging portion of the handle. A ratcheting mechanism which includes a manual switch  140  (e.g., lever or slide) that causes a pawl to engage and disengage a rack of spaced apart teeth. The pawl and rack regulate linear movement of the claw assembly  160 . 
         [0032]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as shown in  FIG. 2 . The spring may be a coil, leaf or other type of biasing means that resists compression. A removable cover  135  closes the opening of the spring compartment  130 . The cover  135  fits flush against the opening so as to avoid interference with up and down motion of the claw assembly  160 . 
         [0033]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin  146  and biased to pivot towards an abutting nail head. The lever  145  may also be operably coupled to a guide rail  147  by guide pins  148 . Pivoting movement of the lever  145  may engage and release the pawl to allow locking and refraction of the claw assembly  160 . 
         [0034]    A permanent magnet  165  is attached at the apex of the handle  110 . The magnet  165  is stationary. The claw assembly  160  is comprised of a material to which the magnet  165  is magnetically attracted (e.g., a ferrous material). When the claw assembly  160  is in the fully raised (i.e., topmost) position as shown in  FIG. 2 , the magnet  165  helps securely hold the claw assembly  160 . Rattling, jostling and unintended movement of the claw assembly  160  are alleviated by the magnet  165 . 
         [0035]      FIG. 6  provides a perspective view of an exemplary embodiment of a claw assembly  160  for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail  152 . The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. Flanged channels  162 ,  164  are configured to engage and glide in channels along an engaging portion of a handle. A ratcheting mechanism which includes a manual switch  140  that causes a pawl  147  to engage and disengage a rack of spaced apart teeth. The pawl  147  and rack regulate linear movement of the claw assembly  160 . 
         [0036]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin  146  and biased to pivot towards an abutting nail head. The lever  145  may also be operably pivotally coupled to a second lever  149  configured to pivot in a direction opposite to the pivoting direction of the primary lever  145 . The secondary lever  149  may be spring biased, such as with a torsion spring. Pivoting movement of the primary lever  145  may engage and release the pawl to allow locking and refraction of the claw assembly  160 . 
         [0037]      FIG. 7  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail  152 . The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. A flanged channel is configured to engage and glide in channels  148  along an engaging portion of the handle. A ratcheting mechanism causes a pawl  173  to engage and disengage a rack  125  of spaced apart teeth. The pawl  173  and rack  125  regulate linear movement of the claw assembly  160 . 
         [0038]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as shown in  FIG. 7 . The spring  131  may be a coil, leaf or other type of biasing means that resists compression. A removable cover  131  closes the opening of the spring compartment  130 . The cover  131  fits flush against the opening so as to avoid interference with up and down motion of the claw assembly  160 . 
         [0039]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin  146  and magnetically biased to pivot to a locking position. A magnet  172  is provided to urge the lever and pawl into a locking position. Pivoting movement of the lever  145  may engage and release the pawl  173  to allow locking and retraction of the claw assembly  160 . 
         [0040]      FIG. 8  provides a perspective view of another exemplary embodiment of a hammer  100  with a linearly adjustable ratcheting claw assembly  160  in a retracted position according to principles of the invention. The hammer  100  is substantially the same as the embodiment in  FIG. 2 . The claw assembly  160  is shown moved linearly relative to the striking head  105  of the hammer to an extracting position. The distance between the fulcrum at the magnet  165  and the engaged nail  152  has been substantially increased. This distance provides increased leverage and range of motion to extract a nail  152 . After the nail is extracted, the pawl may be released (i.e., disengaged from the rack) and the claw assembly may be returned to its fully extended position as shown in  FIG. 2 . 
         [0041]      FIG. 9  schematically illustrates an exemplary embodiment of a ratcheting rack  200  and pawl  215  assembly for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. The ratchet allows continuous linear motion in only one direction (i.e., the retracting direction) while preventing motion in the opposite direction (the extended direction), until a pawl  215  is released. The ratchet includes a linear rack  200  with teeth  205 , and a pivoting, springloaded finger called a pawl  215  that engages the teeth. The teeth  205  are uniform but asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the other edge. When the pawl is moving in the unrestricted (i.e., retracting) direction, the pawl  215  easily slides up and over the gently sloped edges of the teeth, with a spring forcing it (possibly with an audible “click”) into the depression  210  between the teeth as it passes the tip of each tooth. When the pawl  215  moves in the opposite (backward) direction, however, the pawl will catch against the steeply sloped edge of the first tooth it encounters, thereby locking it against the tooth and preventing any further motion in that direction. The pawl&#39;s range of rotation is controllably restricted to ensure catching until released, while allowing pivoting for retracting linear movement. By way of example and not limitation a stop  240  may prevent rotation of the pawl in one direction  235 , until the stop is moved, while permitting substantial rotation in the opposite direction  230 . In one embodiment, the pawl  215  is coupled to a lever  220  acted upon, directly or indirectly, by the head of a nail. The head of a nail pushing against the lever  220  causes the pawl  215  to move in the retracting direction along the rack  200 . 
         [0042]      FIG. 10  provides a perspective view of another exemplary embodiment of a hammer with a linearly adjustable ratcheting claw according to principles of the invention. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail  152 . The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. A flanged channel is configured to engage and glide in channels  148  along an engaging portion of the handle. A ratcheting mechanism with a pivoting lever  180 , a ratchet body and a ratchet switch  184  causes a pawl to engage and disengage a rack  125  of spaced apart teeth. The pawl and rack  125  regulate linear movement of the claw assembly  160 . The switch  184  affects the angle of the pawl relative to the engaged teeth of the rack  125  to allow or resist movement in one direction or another. Thus, in this embodiment, movement in each direction (i.e., up/down) is controlled by ratcheting. 
         [0043]    Alternatively, the switch  184  may have an engaged position and a free position. In the engaged position, the ratchet causes the claw assembly to move linearly away from the striking head  105  of the hammer. In the free position, the pawl is disengaged and the claw assembly may be slid linearly in either direction. 
         [0044]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin  146  and magnetically biased to pivot to a locking position. A magnet  172  is provided to urge the lever and pawl into a locking position. Pivoting movement of the lever  145  may engage and release the pawl  173  to allow locking and retraction of the claw assembly  160 . 
         [0045]      FIG. 11  provides a perspective view of an exemplary embodiment of a claw assembly  160  for a hammer with a linearly adjustable ratcheting claw according to principles of the invention. The claw assembly  160  includes a claw  150  with a v-shaped groove  155  for engaging a nail  152 . The claw assembly  160  is movable linearly relative to the striking head  105  of the hammer. Flanged channels  162 ,  164  are configured to engage and glide in channels along an engaging portion of a handle. A ratcheting mechanism which includes a manual switch  140  that causes a pawl  147  to engage and disengage a rack of spaced apart teeth. The pawl  147  and rack regulate linear movement of the claw assembly  160 . 
         [0046]    A nail head lever  145  is attached to the concave side of the claw  150 . The lever  145  extends outwardly from the handle to a point past the vertex of the v-groove. During extraction of a nail using the claw  150 , the head of the nail may bear against the lever  145 . The lever  145  may be attached with a pivot pin  146  and biased to pivot towards an abutting nail head. The lever  145  may also be operably pivotally coupled to a second lever  149  configured to pivot in a direction opposite to the pivoting direction of the primary lever  145 . The secondary lever  149  may be spring biased, such as with a torsion spring. Pivoting movement of the primary lever  145  may engage and release the pawl to allow locking and refraction of the claw assembly  160 . 
         [0047]    A spring compartment  130  in the handle  110  contains a compression spring  131  that urges the claw assembly towards its topmost position, as discussed above in relation to  FIG. 2 . The spring may be a coil, leaf or other type of biasing means that resists compression. 
         [0048]    While an exemplary embodiment of the invention has been described, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum relationships for the components and steps of the invention, including variations in order, form, content, function and manner of operation, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. The above description and drawings are illustrative of modifications that can be made without departing from the present invention, the scope of which is to be limited only by the following claims. Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, 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, and accordingly, all suitable modifications and equivalents are intended to fall within the scope of the invention as claimed.