Patent Publication Number: US-6986504-B1

Title: Tool for pulling nails and other protrusions

Description:
FIELD OF THE INVENTION 
   This document concerns an invention relating generally to hand tools, and more specifically to hand tools which allow the pulling of nails or other small protrusions (screw or rivet heads, nuts, pegs, etc.) from the surfaces from which they protrude. 
   BACKGROUND OF THE INVENTION 
   Claw hammers are perhaps the best known tool for pulling nails from boards or other surfaces. The claw hammer has a curved top bearing surface which ends in a furcated tail or “claw” opposite the hammer head. When a nail is to be pulled, the nail head is situated between the furcations, and the top bearing surface is rolled along the board (or other surface from which the protrusion extends) in a tail-to-head direction so that the curvature of the bearing surface lifts the furcations (and thus the nail head) from the board. The problem with this arrangement is that the cap of the nail head—which bears against the furcations of the hammer tail, with the nail shaft resting in the crotch between the furcations—may yield if the nail is firmly grasped by the board, effectively stripping the nail cap from the nail head. The furcations are then unable to grasp the nail head, and the claw hammer can no longer pull the nail. Thus, claw hammers are often ineffective in pulling nails or other protrusions where such protrusions lack sturdy, well-defined caps (or where they lack other heads of greater diameter than the adjacent part of the protrusion). 
   SUMMARY OF THE INVENTION 
   The invention involves a pulling tool for pulling out embedded nails and other protruding objects, with the invention being intended to at least partially solve the aforementioned problems by positively grasping the nail during pulling, as opposed to passively doing so as in a claw hammer. To give the reader a basic understanding of some of the advantageous features of the invention, following is a brief summary of the preferred versions  100  and  200  of the pulling tool shown in  FIGS. 1   a – 1   d  (which will be collectively referred to as  FIG. 1 ) and  FIGS. 2   a – 2   c  (which will be collectively referred to as  FIG. 2 ). As this is merely a summary, it should be understood that more details regarding the preferred versions may be found in the Detailed Description set forth elsewhere in this document. The claims set forth at the end of this document then define the various versions of the invention in which exclusive rights are secured. 
   Preferred versions of the pulling tool  100 / 200  include an elongated handle  102 / 202  having a tool head  104 / 204  at its end, an anchor  106 / 206  fixed with respect to the handle  102 / 202  (preferably on the tool head  104 / 204 ), and a jaw  108 / 208  which is pivotable with respect to the anchor  106 / 206 . The jaw  108 / 208  includes a bearing surface  110 / 210  which preferably curves in an arc from a jaw tip  112 / 212  to a jaw tail  114 / 214 . The bearing surface  110 / 210  extends along planes perpendicular to the axis about which the jaw  108 / 208  pivots (with the pivot  116 / 216  for the jaw  108 / 208  being situated along the jaw  108 / 208  between its jaw tip  112 / 212  and its jaw tail  114 / 214 ), such that the bearing surface  110 / 210  may “roll” or pivot over a surface (such as a board with a nail embedded therein) along planes coinciding with the planes along which the jaw  108 / 208  pivots. A cutout  118 / 218  (e.g., an aperture in the jaw  108 / 208 ) is situated between the jaw tip  112 / 212  and the jaw tail  114 / 214 , and extends through the jaw  108 / 208  from the bearing surface  110 / 210 . One side of the cutout  118 / 218  is bounded by a jaw grasping face  120 / 220  which is situated adjacent to the pivot  116 / 216 , and which faces toward the jaw tail  114 / 214 . The jaw grasping face  120 / 220  is preferably oriented at least substantially perpendicular to the bearing surface  110 / 210 . 
   The jaw  108 / 208  is pivotable between an open state ( FIGS. 1   a – 1   b  and  2   b ) and a closed state ( FIGS. 1   c – 1   d  and  2   c ). In the open state, an open mouth  122 / 222  is defined in the bearing surface  110 / 210  between the jaw grasping face  120 / 220  and the anchor  106 / 206 , allowing a nail or other protrusion to be inserted into (or removed from) the mouth  122 / 222 . As the jaw  108 / 208  is moved from the open state to the closed state, the anchor  106 / 206  moves into the cutout  118 / 218  of the jaw  108 / 208  and toward the jaw grasping face  120 / 220  until it sits closely adjacent the jaw grasping face  120 / 220 . At this point, the mouth  122 / 222  is at least substantially closed and a nail or other protrusion may be grasped in the mouth  122 / 222  (i.e., between the anchor  106 / 206  and the jaw grasping face  120 / 220 ). 
   To pull a nail extending from a board, or to grasp and pull another protrusion (e.g., a peg, rivet head, protruding nut, etc.), the jaw  108 / 208  is pivoted to its open state and the protrusion is inserted in the open mouth  122 / 222  against the jaw grasping face  120 / 220 , and the surrounding bearing surface  110 / 210  of the jaw  108 / 208  may be situated upon the board or other surface from which the protrusion extends. The jaw  108 / 208  may then be pivoted to its closed state such that the mouth  122 / 222  closes about the protrusion. The handle  102 / 202  of the pulling tool may then be pulled so that the handle  102 / 202  travels in the direction in which the jaw tail  114 / 214  points or extends, causing the bearing surface  110 / 210  to roll across the surface from which the protrusion extends. Such rolling starts with the regions of the bearing surface  110 / 210  nearer the jaw tip  112 / 212  contacting the board or other surface from which the protrusion extends, and ends with regions of the bearing surface  110 / 210  nearer the jaw tail  114 / 214  contacting the board/surface. Owing to the curvature of the bearing surface  110 / 210 , this action begins lifting the mouth  122 / 222  away from the surface from which the protrusion extends, and at the same time, the jaw tail  114 / 214  presses against the surface, thereby serving to more firmly close the mouth  122 / 222  about the protrusion. As a result, the harder one attempts to pull a nail or other protrusion, the more firmly the jaw  108 / 208  is urged shut, and the more tightly the protrusion is grasped. This positive grip even allows the pulling tools  100 / 200  to pull headless nails out of boards, since the grasp of their jaws  108 / 208  on a headless nail shaft is sufficiently strong to allow the nail to be pulled. In tests, the pulling tools  100 / 200  have even been capable of grasping a pointed tip of a nail protruding from a board, and pulling the entirety of the nail through the board tip-first (and cap last, with the cap being bent to trail behind). 
   As can be seen from the drawings, the pulling tool can be provided in a variety of forms, such as in a crowbar  100  (as shown in  FIG. 1 ) or in a hammer  200  (as shown in  FIG. 2 ). In the crowbar  100 , the anchor  106 —which is defined at the tool head  104  of the handle  102 —is pivotally affixed within the cutout  118  by the pivot  116 . The jaw tip  112  is furcated, and is equivalent to the working end of the bend of a standard crowbar  100 . The jaw tail  114  may be furcated as well if desired. The crowbar  100  can be used as a pulling tool as described above, or as a standard crowbar. When using the crowbar  100  in standard fashion, the jaw  108  is urged into its closed state so that the anchor  106  bears against the jaw grasping face  120  (see  FIGS. 1   b  and  1   d ), thereby holding the jaw  108  immobile with respect to the handle  102  so that the jaw  108  will not yield during crowbar use as the jaw tip  112  is used to lift one object from another. 
   In the hammer  200  ( FIG. 2 ), the pivot  216  is provided at the jaw tip  212 , and the cutout  218  is spaced from (but adjacent to) the jaw tip  212  and the pivot  216 . The anchor  206 , which is (as with the crowbar  100 ) effectively defined as an extension of the handle  202 , is not pivotally pinned within the cutout  218 , but instead is received within the cutout  218  as the jaw  208  moves toward its closed state. It is useful to provide the end of the hammer handle  202  opposite the tool head  204  as a sleeve  224  which may be telescopically extended from the handle shaft  226  (and fastened at a desired extension by a threaded fastener  228 ), so that the handle  202  can be extended to provide better leverage when pulling a nail or other protrusion. 
   Further advantages, features, and objects of the invention will be apparent from the following detailed description of the invention in conjunction with the associated drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1   a – 1   d  present perspective views of a first version of a pulling tool which exemplifies the invention, wherein the pulling tool is provided in the form of a crowbar  100  (or more accurately a crowbar head), with  FIGS. 1   a  and  1   b  showing the jaw  108  in the open state (with the mouth  122 ,  FIG. 1   b , being open to receive a nail head or other protrusion), and  FIGS. 1   c  and  1   d  showing the jaw  108  in the closed state. 
       FIGS. 2   a – 2   c  present perspective views of a second version of a pulling tool which exemplifies the invention, wherein the pulling tool is provided in the form of a hammer  200  (or more accurately a hammer head), with  FIG. 2   a  presenting an exploded (disassembled) perspective view of the head of the hammer  200 ,  FIG. 2   b  showing the jaw  208  in the open state (with the mouth  222  being open to receive a nail head or other protrusion), and  FIG. 2   c  showing the jaw  208  in the closed state. 
   

   DETAILED DESCRIPTION OF PREFERRED VERSIONS OF THE INVENTION 
   Referring initially to  FIGS. 1   a – 1   d  (which are collectively referred to as  FIG. 1 ), the pulling tool is presented in the form of a crowbar  100 . The crowbar  100  has an elongated handle  102  with a tool head  104  at one end and a prying wedge  124  at its opposite end. The tool head  104  defines an anchor  106  against which a nail or other protrusion will be grasped, and it includes a jaw  108  which is pivotally affixed to the anchor  106  at pivot  116 . The jaw  108  includes a jaw tip  112  and an opposing jaw tail  114 , both of which are preferably defined as furcated prying wedges. A top bearing surface  110  curves in an arc from the jaw tip  112  to the jaw tail  114 . An opposing jaw bottom surface  126  ( FIGS. 1   a  and  1   c ), which faces the handle  102 , also extends between the jaw tip  112  and the jaw tail  114 . A cutout  118 , defined as an aperture extending between the bearing surface  110  and the jaw bottom surface  126 , is situated between the jaw tip  112  and the jaw tail  114 . One side of the cutout  118  is bounded by a jaw grasping face  120  which is situated adjacent to the pivot  116 , and which faces toward the jaw tail  114 . The anchor  106  of the tool head  104  is pinned by the pivot  116  within the cutout  118 , and between the jaw tip  112  and jaw tail  114 , such that the jaw  108  can pivot  116  between an open state ( FIGS. 1   a – 1   b ) and a closed state ( FIGS. 1   c – 1   d ). In the open state, an open mouth  122  ( FIG. 1   b ) is defined in the bearing surface  110  between the jaw grasping face  120  and the anchor  106 , allowing a nail or other protrusion to be inserted into (or removed from) the mouth  122 . As the jaw  108  is pivoted from the open state to the closed state, the anchor  106  moves further into the cutout  118  of the jaw  108  and toward the jaw grasping face  120  until it sits closely adjacent the jaw grasping face  120 . At this point, the mouth  122  is at least substantially closed, and a nail or other protrusion previously inserted into the open mouth  122  may be grasped in the mouth  122  between the anchor  106  and the jaw grasping face  120 . Both the jaw grasping face  120  and the opposing face of the anchor  106  are preferably oriented at least substantially perpendicular to the bearing surface  110  when the jaw  108  is in its closed state so as to better grasp a nail head or other protrusion when the bearing surface  110  rests against the surface from which the protrusion extends (it being assumed that such a protrusion will usually protrude perpendicularly from such a surface). 
   To pull a nail extending from a board (or to grasp and pull another protrusion), the jaw  108  is pivoted to its open state ( FIGS. 1   a – 1   b ) and the protrusion is inserted in the open mouth  122  against the jaw grasping face  120 , and the surrounding bearing surface  110  of the jaw  108  may be situated upon the board or other surface from which the protrusion extends. The handle  102  is then pivoted so that the jaw  108  is in its closed state ( FIGS. 1   c – 1   d ) such that the mouth  122  closes about the protrusion, with the protrusion being sandwiched between the anchor  106  and the jaw bearing surface  110 . The handle  102  of the pulling tool  100  may then be pulled so that the handle  102  travels in the direction in which the jaw tail  114  points/extends, with the bearing surface  110  rolling across the surface from which the protrusion rises. Owing to the curvature of the bearing surface  110 , this rolling action begins lifting the mouth  122  away from the surface from which the protrusion extends, thereby pulling the nail or other protrusion. At the same time, as the bearing surface  110  rolls across the surface from which the protrusion extends (with the bearing surface  110  rolling from its regions nearer its jaw tip  112  towards regions nearer its jaw tail  114 ), the pressure of the jaw tail  114  against the surface from which the protrusion extends will force the jaw  108  closed, thereby serving to more firmly clamp the mouth  122  about the protrusion. As a result, the harder one attempts to pull a nail or other protrusion, the more firmly it is grasped between the jaw bearing surface  110  and the anchor  106 . By continuing to roll the bearing surface  110  across the surface from which the protrusion extends, the protrusion will be pulled from the surface. The crowbar  100  can then be removed from the surface, and the jaw  108  may be pivoted to its open state to release and discard the protrusion. 
   The crowbar  100  is also usable as a standard crowbar  100 . Here, where the head of the crowbar  100  is to be used in standard fashion, the jaw  108  is simply pivoted into its closed state ( FIGS. 1   c – 1   d ) so that the anchor  106  bears against the jaw grasping face  120 . When the jaw tip  112  is then used to pry objects apart, the jaw  108  is effectively held immobile with respect to the handle  102  so that the jaw  108  will not yield during crowbar use. 
   Referring then to  FIGS. 2   a – 2   c  (which are collectively referred to as  FIG. 2 ), the pulling tool is presented in the form of a hammer  200  (or more accurately a hammer head, as depicted in  FIG. 2   a , which is preferably provided in conjunction with the handle  202  depicted in  FIGS. 2   b – 2   c ). The handle  202  usefully includes a sleeve  224  which may be telescopically extended from the handle shaft  226  as shown in  FIGS. 2   b – 2   c , and which may be fastened at a desired extension by a threaded fastener  228  extending through the sleeve  224  to engage the handle shaft  226 . Such an extendible handle  202  allows a user to attain better leverage when using the hammer  200  to pull a nail or other protrusion. 
   The hammer head includes an anchor  206  (best seen in  FIG. 2   a ) which is fixed with respect to the tool head  204  and the handle  202 , and which is defined as a block protruding from a depressed head surface  230  (also best seen in  FIG. 2   a ) and spaced from opposing flange-like head sides  232  which rise from the head surface  230 . A jaw  208  is pivotally affixed to the head sides  232  at a pivot  216  provided on the jaw tip  212 , and the jaw  208  further includes a jaw tail  214  opposite the jaw tip  212 , a top bearing surface  210  curving in an arc between the jaw tip  212  and the jaw tail  214 , and a lower jaw surface (not shown) between the jaw tip  212  and the jaw tail  214  and opposite the jaw bearing surface  210 . The jaw  208  can thereby rotate about the pivot  216  toward and away from the anchor  206 . 
   A cutout  218  is defined in the jaw  208  between its bearing surface  210  and its lower jaw surface, and between the jaw tip  212  and the jaw tail  214 . One side of the cutout  218  is bounded by a jaw grasping face  220  which is situated adjacent to the pivot  216  and which faces toward the jaw tail  214 . When the jaw  208  pivots from its open state (shown in  FIG. 2   b ) with its tail  214  spaced from the depressed head surface  230 , to its closed state (shown in  FIG. 2   c ) with its tail  214  closely adjacent to the depressed head surface  230 , the anchor  206  moves into the cutout  218  to be complementarily received therein. Thus, when the jaw  208  is in its open state, an open mouth  222  is defined in the bearing surface  210  between the jaw grasping face  220  and the anchor  206 , allowing a nail or other protrusion to be inserted into (or removed from) the mouth  222 . As the jaw  208  is moved from the open state to the closed state, the anchor  206  moves into the cutout  218  of the jaw  208  and toward the jaw grasping face  220  until it sits closely adjacent the jaw grasping face  220 . At this point, the mouth  222  is at least substantially closed and a nail or other protrusion may be grasped in the mouth  222  (i.e., between the anchor  206  and the jaw grasping face  220 ). The jaw grasping face  220 , as well as the face of the anchor  206  against which the jaw grasping face  220  rests when the jaw  208  is in its closed state, are preferably oriented at least substantially perpendicular to the bearing surface  210  to better grasp any protrusion situated in the mouth  222 . 
   To use the hammer  200  to pull a nail (or another protrusion) extending from a board or other surface, a user may use the furcated claw of the hammer  200  in standard fashion (the furcations not being visible in  FIG. 2 ), or may instead use the jaw  208 . The jaw  208  is pivoted to its open state ( FIG. 2   b ) and the protrusion is inserted against the jaw grasping face  220  in the open mouth  222 . The surrounding bearing surface  210  of the jaw  208  is situated upon the board or other surface from which the protrusion extends. The jaw  208  is then pivoted toward its closed state such that the mouth  222  closes about the protrusion, with the protrusion being sandwiched between the jaw grasping face  220  and the anchor  206 . The handle  202  of the pulling tool may then be pulled so that the handle  202  travels in the direction in which the jaw tail  214  (and the claw of the hammer  200 ) points, with the bearing surface  210  rolling across the surface from which the protrusion extends. Owing to the curvature of the bearing surface  210 , the mouth  222  begins lifting away from the surface from which the protrusion extends, thereby pulling the protrusion from its surrounding surface. At the same time, the pressure on the bearing surface  210  at the jaw tail  214  serves to more firmly close the mouth  222  about the protrusion. As a result, the harder one pulls the nail or other protrusion, the more firmly it is grasped during such pulling. 
   From the differing configurations of the crowbar  100  and the hammer  200 , it should be understood that the general configuration of the pulling tool can vary substantially (and can vary quite substantially from the versions shown in the accompanying drawings). It is emphasized that the depicted crowbar  100  and hammer  200  are merely exemplary, and various modifications are also considered to be within the scope of the invention. As examples, the size and configuration of the jaw  108 / 208  can vary substantially, and as the foregoing examples show, the location of the pivot  116 / 216  be changed. The cutout  118 / 218  need not be provided as an aperture bounded by the jaw  108 / 208  on all sides, but could rather be provided as a slot which extends inwardly from one of the sides of the jaw  108 / 208 , as well as from its bearing surface  110 / 210  to its jaw bottom surface (though this arrangement is not preferred). The jaw grasping face  120 / 220  need not be perpendicular to the adjacent bearing surface  110 / 210 , and could instead define a wedge- or chisel-shaped face (which may slightly protrude above the surrounding surface of the jaw  108 / 208 ), so that the jaw grasping face  120 / 220  may “dig” beneath the cap of a nail or other fastener to better grip it. Additionally, the jaw grasping face  120 / 220  may be notched or furcated so that the notch may receive the shaft of a nail or other protrusion. Alternatively, the jaw grasping face  120 / 220  could have a sharpened wedge- or chisel-shaped face so that a protrusion is cut off by the pulling tool rather than pulled. Additionally or alternatively, the face of the anchor  106 / 206  which opposes the jaw grasping face  120 / 220  (and abuts the jaw grasping face  120 / 220  when the jaw  108 / 208  is in its closed state) could also have a notched/furcated surface, or a sharpened surface, to attain the foregoing objectives. The bearing surface  110 / 210  need not be curved, but can simply be formed as (for example) a flat surface whereby a protrusion is pulled not so much by a rolling action, but more of a levering action. Additionally, the bearing surface  110 / 210  need not be continuous (i.e., it might include a valley or other depression formed therein), though it preferably has a continuous contour/curvature so that any rolling action generated by the bearing surface is smooth. 
   The pulling tool may also be embodied in a variety of forms other than as a crowbar or hammer, e.g., it may be provided solely as a pulling tool (without hammer or crowbar structure), as by removing the pounding face and the claw of the hammer  200 . The pulling tool could also be provided as a member which clamps or bolts onto preexisting separate tools. For example, considering the hammer  200 , the top of the tool head  204  (i.e., the part defining the anchor  206 , jaw  208 , etc.) could be formed as a separate member which can be bolted or otherwise fastened atop a preexisting hammer, so that the hammer could be retrofit to attain the invention. 
   The invention is not intended to be limited to the preferred versions described above, but rather is intended to be limited only by the claims set out below. Thus, the invention encompasses all different versions that fall literally or equivalently within the scope of these claims.