Abstract:
A attachment for a pry bar for pulling up a stake is disclosed, wherein the stake puller includes a coupler attachable to the pry bar and a grip pivotally connected to the coupler on an axis substantially perpendicular to a rotational axis of the pry bar, the grip being adapted to releasably attach to the stake. Other embodiments as described herein.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
   This application claims priority to provisional application Ser. No. 60/574,607 filed May 25, 2004 for STAKE PULLER. The subject matter of the above-identified application is incorporated herein by reference in their entirety for all purposes. 

   TECHNICAL FIELD 
   The present invention relates to tools that remove stakes from the ground. More particularly, the invention provides an improved attachment for a pry bar to remove stakes from the ground. 
   BACKGROUND 
   Cement, concrete, and other moldable construction materials typically are poured into molds that are defined by forms, which are wooden planks or boards or other materials providing the outline of the mold. While the concrete is poured and drying, the forms are held in place by stakes driven into the ground adjacent the form. The concrete may be poured in large quantities that produce considerable outward pressure on the forms, and thus the stakes are driven deeply into the ground. The stakes and the forms are removed after the concrete has set and significant upward pressure must be exerted on the stakes to remove them. The stakes typically have smooth sides and no head or other partially horizontal structures to accommodate the upward pressure applied by a typical pry bar. Various tools have been devised for pulling up the stakes, but only with complex structures or inefficient modes of operations. 
   SUMMARY 
   An attachment for a pry bar to use for pulling up stakes may include a coupling portion to receive the typically wedge-shaped tip of the pry bar. A post may be mounted on the coupling portion and extends in front of the coupling portion. A grip may be mounted on the post to rotate about the post about a channel formed with the grip. The grip typically includes a forward-facing, U-shaped slot for receiving and gripping a stake to be pulled up from the ground. The grip is rotatable, by the channel&#39;s rotating on the post, about an axis that is generally perpendicular to the axis of rotation for the pry bar. The grip&#39;s rotation may be limited by stops on the grip, post, and/or coupler. When the grip is applied to a stake and a handle of the pry bar is pushed down, drawing the grip upwards, the grip rotates slightly and takes hold of the stake at opposite edges of the sides of the U-shaped slot. As the grip and stake are drawn upward, a recess in the bight of the U-shaped slot provides space to receive the stake, allowing the stake to be maintained deep in the slot. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a stake puller in accordance with an embodiment of the present invention, functionally attached to a pry bar. 
       FIG. 2  is a top plan view of a stake puller with a pry bar to which it can be attached in accordance with an embodiment of the present invention, showing a coupler, a post mounted on the coupler, a grip pivotally mounted on the post, a C-shaped ring holding the grip on the post, and a U-shaped slot formed on a forward edge of the grip. 
       FIG. 3  is a front elevation view of the stake puller of  FIG. 2  showing the grip in a nominal position, and in dashed lines, in a lower rotated position. 
       FIG. 4  is a right side elevation view of the stake puller of  FIG. 2  showing the coupler having a wedge shape with an inner wedge-shaped cavity, in dashed lines, for receiving the wedge-shaped tip of a pry bar. 
       FIG. 5  is a left side elevation view of the stake puller of  FIG. 2  showing the coupler and grip and an upper stop for the rotation of the grip. 
       FIG. 6  is a cross-sectional view of the grip&#39;s slot, showing the beveled and sloped edges. 
       FIG. 7  is a cross-sectional view of the grip and post, showing the upper and lower stops on the grip connecting portion. 
       FIG. 8  is a partial top plan view of the grip and post, showing an alternate method of attaching the grip to the post. 
       FIG. 9  shows the stake puller in operation with an upper edge of the left-hand side of the grip&#39;s slot and a lower edge of the right-hand side of the grip&#39;s slot grabbing hold of the stake and urging it upward. 
       FIG. 10  is a partially cutaway side view of the stake puller in an upwardly-moved position, showing the stake in a beveled recess in the grip&#39;s slot. 
       FIG. 11  shows the stake puller during a reverse stroke of operation, showing the grip rotated to a position where it is able to slide down the stake without grabbing the stake. 
   

   DETAILED DESCRIPTION 
   As shown in  FIG. 1 , a stake puller according to an embodiment of the present invention is indicated generally at  10 . Stake puller  10  includes a coupling portion  12  and a grip  14 . Coupling portion  12  preferably is used to attach stake puller  10  to a pry bar  16  in a releasable friction fit or other suitable manner. Alternatively, the stake puller may be constructed as a single device, including the pry bar. A typical pry bar includes, as also shown in  FIG. 1 , a long handle  18 , a fulcrum  20 , and a wedge-shaped tip  22 . The pry bar in use is placed on the ground G adjacent a stake  24  and the pry bar is rotatable about an axis A generally coincident with fulcrum  20 . Axis A is generally transverse a long axis L of the pry bar. Coupler  12  and grip  14  are typically made of metal of suitable strength or other appropriate materials, such as 4140 stainless steel hardened to 48 HRC. 
   Referring now to  FIGS. 2–7 , coupler  12  may include a rear open end  26  for receiving tip  22  of pry bar  16  in a wedge-shaped inner cavity  28 . Rear open end  26  typically includes lower rear edge  29   a , upper rear edge  29   b , and side rear edges  29   c  and  29   d . Preferably, lower rear edge  29   a  extends further rearward than upper rear edge  29   b  in order to aid the insertion of tip  22  of pry bar  16 . 
   Coupler  12  may include an upper surface  30  to which a grip mount, such as post  32 , is fixedly mounted, e.g., by welds  34 . Alternatively, post  32  may be removably mounted, or formed integrally as part of coupler  12  or mounted by any other suitable means. Post  32  typically includes a forward portion  36  extending forward of a front edge  38  of coupler  12 . 
   Grip  14  may be mounted to forward portion  36  of post  32  by a channel  40 , which may be bored through grip  14  with an inner diameter sized to receive post  32  therein, allowing grip  14  to rotate about an axis GA generally defined by post  32 . Axis GA is typically substantially perpendicular to the rotational axis A (the fulcrum axis) of the pry bar. A clamp  42 , fixed near the end of post  32  in a suitable manner, retains grip  14  on post  32 . In the illustrated embodiment, clamp  42  is a thin C-shaped clamp frictionally inserted into a groove  43  formed into post  32 . Clamp  42  may be removable in order to remove grip  14  from post  32  in the case that grip  14  becomes damaged, or if the operator desires to install a grip  14  more suitable to pull a particular type of stake. 
   An alternative method to retain grip  14  on post  32 , as shown in  FIG. 8  would include fixing a cap  42   a  on the end of post  32  in a suitable manner, such as by welding. Cap  42   a  may also provide a striking point for a hammer to drive the coupler on the pry bar for a secure, yet removable attachment. Cap  42   a  is preferably a domed rivet, or alternatively may be a metal washer between about 1/16-inch and about ¼-inch thick or other suitable part for retaining the grip on the post. 
   Grip  14  may include a body  44  extending out from a connecting portion  46 , through which channel  40  extends. The body and connecting portion may be machined from a single piece of material, or may be welded together or assembled in any suitable manner. Body  44  includes a slot for receiving stake  24 , preferably a U-shaped slot  48  defined by first side or tooth  50  and a second side or tooth  52  interconnected by a semi-circular bight  54 . Slot  48  may be in a C-shape, or alternatively, any suitable shape for grasping the stake, as will be described below. 
   Slot  48  may include an upper beveled edge  56   a  and a lower beveled edge  56   b . Upper beveled edge  56   a  and lower beveled edge  56   b  may each continuously traverse the entirety of slot  48 . Alternatively either upper beveled edge  56   a  or lower beveled edge  56   b  may each traverse only a portion of slot  48 . Preferably, upper beveled edge  56   a  will traverse at least side  50  of slot  48  and lower beveled edge  56   b  will traverse at least side  52  of slot  48 . 
   Slot  48  may also include a lower sloped edge  58  in bight  54 . Lower sloped edge  58  may extend either through a portion of the thickness of bight  54 , or through the entire thickness of bight  54 , as shown in  FIG. 6 . In the case where slot  48  includes upper beveled edge  56   a , lower sloped edge  58  may extend either through a portion of the thickness of bight  54 , or to upper beveled edge  56   a.    
   Grip  14  may be freely rotatable about post  32 , but typically the rotation is limited by a lower stop to a lower position shown in  FIG. 3  which is about 20-degrees below a level position. The angle for the lower stop is generally chosen for convenient operation of the stake puller consistent with allowing enough rotation for the grip to grab the stake, as will be discussed further below, but not so much rotation as to require the operator to position the grip with one hand while attaching it to a stake. The stake puller as shown can be coupled to the stake while the operator holds only the pry bar with both hands for efficient operation. The rotation of the grip relative to the coupler is limited in the preferred embodiment by edges machined into connecting portion  46  butting against the top surface  30  of coupler  12 , but any suitable construction providing the relative rotation limitation may be used. 
   A lower stop  60  may be provided on connecting portion  46 , as shown in  FIG. 7 . As grip  14  rotates about post  32 , lower stop  60  contacts upper surface  30  of coupler  12 , limiting the rotation of the grip. An upper stop  62  may be provided on connecting portion  46  to limit the upper rotation of the grip. Upper stop  62  allows a ratcheting operation of grip  14  by limiting the rotation of the grip as the grip is moved back down the stake after an upward-pulling motion is executed. 
   The operator of the stake puller will insert the wedge shaped tip  22  of pry bar  16  into wedge-shaped cavity  28  of coupler  12 . The extension of lower rear edge  29   a  beyond upper rear edge  29   b  allows the operator to insert pry bar  16  into coupler  12  with needing to hold stake puller  10  in one hand and pry bar  16  in the other. 
   Operation of the stake puller to draw stake  24  out of the ground is shown in  FIGS. 9–11 . Slot  48  is typically sized slightly wider than the stake desired to be pulled. The operator places the pry bar, with the stake puller attached, on the ground on the fulcrum point and slides the bar forward. With grip  14  rotated to lower stop  60 , upper beveled edge  56   a  on side  50  of slot  48  and lower beveled edge  56   b  on side  52  of slot  48  provide more clearance for stake  24  to be inserted into slot  48 . The operator pushes the pry bar forward until stake  24  is fully within the slot and is pressed against bight  54  of slot  48 . 
   Then the operator presses the pry bar handle down, rotating the bar at the fulcrum point about axis A, and causing grip  14  to move upward. As grip  14  is lifted, it rotates about axis GA until an upper edge  64  of side  50  and a lower edge  66  of side  52  contact the wall of stake  24 . Initial friction between upper edge  64  tends to cause the grip to rotate upwards which tightens edges  64  and  66  onto stake  24  until the stake is firmly grabbed between the edges, as depicted in  FIG. 9 . Then as the pry bar is further rotated, the stake is pulled upwardly as shown by arrow U. As grip  14  rotates upwards, beveled edges  56   a  and  56   b  provide more surface contact with, and less damage to, stake  24 , as the stake is removed. Sloped edge  58  in bight  54  provides a recess into which stake  24  is partially received as grip  14  moves upward, as shown in  FIG. 10 . Sloped edge  58  prevents the stake from being pushed out of slot  48  and helps maintain the grasp of the grip on the stake. 
   When the operator reaches a maximum deflection of the pry bar, the pry bar handle is raised up again to prepare for another pulling operation on the stake. As the handle goes up, grip  14  moves down on stake  24 , which pushes lower edge  66  upwardly, causing grip  14  to rotate back toward a level position. This allows the grip to be easily moved back down. However, the rotation of grip  14  is limited by upper stop  62 , so that grip  14  will not grab stake  24  as the grip is moved down, as shown in  FIG. 11 . This provides the ratcheting feature of the stake removal as mentioned above. Upper stop typically limits rotation of grip  14  to no more than about 5-degrees above level. These operations are repeated until the stake has been suitably pulled out of the ground. 
   Although the present disclosure includes specific embodiments, specific embodiments are not to be considered in a limiting sense, because numerous variations are possible. The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various elements, features, functions, and/or properties disclosed herein. The following claims particularly point out certain combinations and subcombinations regarded as novel and nonobvious. These claims may refer to “an” element or “a first” element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of features, functions, elements, and/or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope to the original claims, also are regarded as included within the subject matter of the present disclosure.