Abstract:
A fastener removing tool in accordance with the invention utilizes a design having a handle portion and a head portion with a bend between the handle portion and the head portion, wherein the head portion has two gripping members that may be opened and closed, and wherein each gripping member further comprises a groove having a pair of opposing gripping edges each of which defines an angle of approximately 90° and where the grooves may be opposing when the halves of the head are in a closed position, and wherein the head portion further comprises a top and an opposing protrusion into which protrusion the grooves extend.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates generally to hand tools, and more particularly to a hand tool for removing threaded fasteners having a head.  
           [0003]    2. Description of the Prior Art  
           [0004]    Quite commonly, threaded fasteners such as screws become difficult to remove, or “frozen,” after insertion. Often, and particularly the case with Phillips head fasteners, the screwdriver slots on the head become stripped when removal is attempted so that it is difficult or impossible to remove the fastener using conventional means such as a screwdriver. One other reason fasteners may be difficult to remove is that they are sealed into place with paint or glue. Yet another reason is that the threads may be corroded (particularly when inserted into metal), causing the threads to become frozen in the bore into which the fastener is inserted.  
           [0005]    Such frozen screws can sometimes be removed by pry-type instruments, such as hammer claws or pry bars, or the screw head can be clipped or chiseled off, or drilled out of the material. At that point, the material must then be prepared to accept a different fastener, which is generally done by oversize drilling and re-tapping, or by resizing the original threaded bore such as by using a “Heli-Coil (™) type threaded insert.  
           [0006]    However, it is most desirable to completely remove the fastener without damaging the threaded bore in the material, and in some cases without damaging the fastener itself. This is particularly important when the fastener is unique or when it is undesirable to create a second opening for a new fastener, such as when building or repairing furniture and the like. In such cases, the frozen fastener must be turned out without the use of vertical force so that the threads on both the fastener and in the material remain intact.  
           [0007]    Pliers (either needle-nosed or ordinary) can sometimes be used to grasp and turn the head of the fastener, but this method of removal is very difficult if the fastener is firmly frozen in place, since the pliers tend to slip off the head of the screw when force is applied.  
           [0008]    Other prior art fastening remover devices, such as those illustrated in U.S. Pat. Nos. 2,043,373 and 4,084,457, utilize a combination of both vertical and rotational forces to effect removal of the frozen fastener. Such fastener removing devices suffer from the drawback of shearing the fastener from its position during application of the vertical forces, thereby damaging the threads on the fastener and the thread imprint on the material, rendering both the fastener and its opening in the material unusable.  
           [0009]    One additional drawback of some prior art devices which use rotational force to remove fasteners is that the means of gripping the fastener may weaken and break with repeated usage.  
           [0010]    Thus, it is an object of the invention to provide a tool for removing threaded fasteners which does not damage the threads on the fasteners or the threads in the fastener bore.  
           [0011]    It is yet another object of the invention to provide a tool for removing threaded fasteners which utilizes only rotational forces for removal.  
           [0012]    It is also an object of the invention to provide a tool for removing fasteners having gripping edges which may be sharpened.  
           [0013]    Yet another object of the invention is to provide a tool for removing threaded fasteners which utilizes a gripping mechanism with improved durability as compared to prior art devices.  
           [0014]    An additional object of the invention is to provide a tool for removing fasteners whereby the tool may be gripped with either one or two hands while applying an evenly distributed rotational force to the circumference of the fastener.  
           [0015]    A more particular object is to provide a tool for removing threaded fasteners of differing head sizes and shapes.  
           [0016]    Other objects will become apparent from the following summary and description of its preferred embodiments.  
         SUMMARY OF THE INVENTION  
         [0017]    A fastener removing tool in accordance with the invention utilizes a design having a handle portion and a head portion, wherein the head portion has two gripping members that may be opened and closed, and wherein each gripping member further comprises a groove having a pair of opposing gripping edges each of which defines an angle of approximately 90° and where the grooves may be opposing when the gripping members are in a closed position, and wherein the head portion further comprises a top and an opposing protrusion into which protrusion the grooves extend. The gripping members are squeezed about the perimeter of the head of the fastener and the gripping edges of each member are oppositely opposed such that the fastener to be removed is gripped between the edges and may be readily rotated and removed without the use of vertical forces. The handle of the invention is angled with respect to the gripping end to provide a an evenly firm grasp of the fastener on the gripping end, with sufficient clearance between the material surface and the handle for a fist to firmly grasp the handle. This angle allows gripping edges to firmly and evenly grasp the outer circumference of the protruding fastener head, which evenly distributes the gripping forces around the fastener head and minimizes slipping of the gripping edges from the fastener. This design maximizes the user&#39;s ability to apply rotational torque to the head of the frozen fastener by applying a closing pressure on the handles (with sufficient clearance of the material surface to use either one or possibly both hands to grip the fastener if necessary) thus allowing the fastener to be turned out without vertical force and without damage to the screw threads or the threaded bore the fastener is inserted into.  
           [0018]    Further features, objects and advantages of the invention will be apparent from the drawings and description set forth below.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is a schematic diagram of a fastener remover made in accordance with the principles of the invention.  
         [0020]    [0020]FIG. 2 is a side perspective drawing of a fastener remover of the invention.  
         [0021]    [0021]FIG. 3 is a side view of a tool of the invention gripping a fastener.  
         [0022]    [0022]FIG. 4 is a top-view of a tool of the invention gripping a fastener.  
         [0023]    [0023]FIG. 5 is expanded view of the gripping end of a tool made in accordance with the principles of the invention illustrating the gripping edges.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    A tool made in accordance with the invention is shown generally in FIG. 1 at  10  and includes two members  12 , each member having a handle end  14  and a gripping end  16 . In this preferred embodiment, the two members are pivotally joined about a rotational axis  18  similar to that seen in pliers, although the joining may be accomplished by any of a number of suitable means which are known to those skilled in tool arts. The joining must only be of a type that allows the two gripping ends  16  to be brought together while holding the handle  20 , which is a double-handled pliers-type device. Once joined, the tool  10  has a handle portion having two handles  14 , and a head portion having and two heads,  22 . Each head has a gripping end  16 , which includes a u-shaped groove  24  (although differently shaped grooves may be used), which groove  24  partly defines the inner wall  26  of each of  2  opposing 90° gripping edges  28 , which edges grasp the circumference of a fastener head  30 , as illustrated in FIGS. 3 and 4.  
         [0025]    The tool  10  is designed with an angular handle bend  32  of approximately 15° to 25° in this embodiment (although any other angle that will provide clearance for a gripping hand will work), providing room for a comfortable grip position for the operator, in contrast to prior art tools which are designed to be held vertically (and thus have little leverage with which to rotate the handle), or which cause the grip on the fastener to be uneven as a result of angling the tool sufficient to grasp and rotate it (such as with ordinary pliers).  
         [0026]    When handle halves  14  are pressed together, the u-shaped grooves  24  in each gripping end  16  define a generally oblong opening  34  in the head  22  of the tool  10 . The grooves  24  are machined so that the sides  26  of the grooves are generally perpendicular to the horizontal plane of the head  22 , as illustrated in FIG. 2. When closed, the gripping edges  28  of each gripping end  16  are adjacent, as illustrated in FIG. 1. During use, the gripping edges  28  are used to grasp the head  30  of the frozen fastener, and to provide a balanced source for rotational torque on approximately opposite sides of the fastener head  30 .  
         [0027]    One significant advantage of a tool of the invention over the prior art is that the tool head  22  is equipped with a gripping protrusion  40 , which protrusion may be attached, or it may be machined as part of head  22 . As illustrated in FIGS.  1 - 3 , when the tool is in the “closed” position, the protrusion  40  is frusto-conical in shape and the gripping surface  42  of the protrusion  40  is flat, although any other shape protrusion and gripping surface may be utilized, as long as the diameter of the gripping surface is less than the diameter of the top of the head when the tool is in the “closed” position. The protrusion assists in raising the tool head  22  off of the material surface  44  to which the fastener  48  is attached (as illustrated in FIG. 3). The protrusion  40  provides clearance for the tool head  22  to be manipulated with minimal scarring or rotational marking or other incurred damage to the material surface  44  during use of the invention in removing fasteners  48 , as illustrated in FIG. 3.  
         [0028]    A second significant advantage of the invention is that each of the four 90° gripping edges  28  grasp only the outer perimeter of the fastener head  30 ; the edges  28  do not come in contact with any surrounding or adjacent surfaces of the parent material  44 .  
         [0029]    To position the tool  10  on a frozen fastener head  30 , the handle ends  14  of the handle  20  are separated, thus separating the gripping ends  16 , which should be separated by a distance wider than the size of the fastener head  30  to be removed.  
         [0030]    The gripping edges  28  should then be positioned around the perimeter of fastener head  30 . Then, inward hand pressure  12  is applied to the handle ends  14  until the gripping edges  28  are at least partially penetrating into the fastener head  30 , as illustrated in FIG. 4, and the gripping pressure is maintained throughout use of the tool  10 . Next, rotational unscrewing torque is applied (generally in the direction illustrated by arrow  46 ) to handle  20 , thus freeing the fastener  48  to rotate sufficient to remove fastener  48  from the material  44 . Because of the protrusion  40  and the head/handle angular bend  32 , slippage of the 90° gripping edges  28  from the fastener head  30  is minimized as compared to prior art designs with less than 45° gripping edges and protrusions. Once the fastener  48  is initially loosened, the fastener may be removed by any suitable means.  
         [0031]    As is apparent from FIGS. 2 and 3, the lateral spacing of the opposing 90° gripping edges  28  must be less than the diameter of the fastener head  30 . Any size spacing is suitable, although it is contemplated that the tool may be manufactured with at least two different dimensional openings—one to accommodate small fastener heads such as, for instance, those fasteners with heads having a diameter of less than ⅜ inch, and one to accommodate larger fastener heads, for instance those fasteners having heads of a diameter of more than ⅜ inch.  
         [0032]    The tool of the invention offers the distinct advantage of providing a positive gripping action in a single horizontal plane, perpendicular to the vertical center line  50  of the fastener  48 . This arrangement maximizes even and constant application for rotational torque to the fastener, minimizing the possibility that the fastener head  30  will be sheared off from the fastener shaft  48 . Moreover, with this design, no application of vertical force is necessary, and thread preservation is maximized.  
         [0033]    The four gripping edges  28  comprise an angle of approximately 90°, providing the edges with maximum strength and gripping action compared to edges of less than 90°. Moreover, if the gripping edges  28  become dull or worn, they are easily resharpened by grinding or filing a small amount of material from each side of the edge, illustrated as edge “A”” or edge “B” of FIG. 5.  
         [0034]    While the preferred embodiment of the invention described above has a pivoting connector in the fashion of common pliers, any connector that provides for tightening the grip halves together while squeezing the handles will be useful in the invention. One alternative connection means is that employed by a vise-type grip.  
         [0035]    The utility and advantages afforded by the subject invention will readily apparent from the specification and the drawings. It should be understood that although specific embodiments are described herein, such embodiments are illustrative and not restrictive, and all variations thereon so not depart from the spirit and scope of the claims.