BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to the field of hand tools. More particularly, the invention pertains to a hand tool having operable gripping jaws for extracting fasteners embedded in a material.
2. Description of Related Art
Fasteners, such as nails, brads, and staples, are commonly used to fasten objects to workpieces such as wood. A hammer, as is used to drive nails and brads, typically includes a claw for removing nails. Unfortunately, the claws of hammers do not grip fasteners with small heads such as finish nails and brads well. Furthermore, the heads of nails and brads are typically driven slightly below the surface of the fastened workpiece so the fasteners are less visible. In order to extract such an embedded fastener using the claws of a hammer, the fastener head must first be raised above the surface of the workpiece in which the fastener is embedded. Furthermore, powered nail guns are increasingly replacing hammers, and often drive nail heads below the workpiece surface, even for common nails. Nail guns typically have no provision for removing nails. Similarly, the use of staples in place of nails is increasing, and stapling tools also lack a means for removing fasteners.
Because of the above considerations there is a need for a dedicated tool to remove embedded fasteners. In addition to the claw found on common hammers, tools have been developed specifically for the purpose of removing fasteners, such as nails, brads, and staples, from workpieces.
A different type of nail extraction tool is typified by the apparatus disclosed in U.S. Pat. No. 143,496 to Capewell. This tool is oriented vertically above the fastener to be removed, and has hinged pincer-like jaws that can be driven under the fastener by means of a slide hammer integral to the vertical handle of the tool. Typically, one of the jaws has an extension that acts as a fulcrum for levering a gripped fastener from the workpiece. This class of tool is best suited to rough work where the appearance of the material is unimportant, such as the disassembly of crates or framing, since the pincers tend to cause significant damage to the surface of the workpiece around the fastener head, and the small area of the fulcrum generally causes damage to the surface against which it is applied. A related class of tool is disclosed in U.S. Pat. No. 6,733,001 to Wagner. The Wagner tool, like the Capewell tool and all other prior art fastener extraction tools with jaws, is oriented vertically above a fastener, in contrast to a tool of the present invention, which is preferably oriented horizontally with respect to the fastener. The Wagner tool includes moveable jaws for grasping the fastener and a fulcrum surface contiguous with one jaw. To apply the Wagner tool, the fastener must be partially emergent from the workpiece since the tool provides no means for digging under a fastener head that is flush with or embedded below the surface of the workpiece. This represents a significant inconvenience, since in many instances a user is forced to apply two separate tools to complete the job: one tool to pry the fastener head proud of the surface, and then the Wagner tool to complete the removal. This represents a significant inconvenience and inevitably slows the progress of the work at hand.
It would be beneficial to have a hand tool better adapted to extract a fastener from a workpiece. Such a hand tool should be capable of both easily accessing a fastener head flush with or below a surface and effectively prying the entire fastener from the workpiece without causing significant damage to the surface.
SUMMARY OF THE INVENTION
A hand tool is disclosed for extracting a fastener from a material. The hand tool has a head with two pivotally joined halves including at least one pair of gripping jaws for gripping a fastener from a horizontal orientation. The tool head preferably includes tips that may be used to dig beneath a fastener head that is flush with or set below a surface. The tool includes a pair of handles operable to close the gripping jaws. The handles are preferably offset above the plane of the tool head such that they operate as a lever in cooperation with a fulcrum on the bottom of the tool head to extract the fastener. In one embodiment, the forward jaws of the tool have concave curved gripping surfaces. In one embodiment, the rearward jaws have non-complementary surfaces.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a side view of a fastener extraction tool in an open position in an embodiment of the present invention.
FIG. 1B shows a top view of the embodiment of FIG. 1A.
FIG. 1C shows a rear view of the embodiment of FIG. 1A.
FIG. 1D shows a front view of the embodiment of FIG. 1A.
FIG. 1E shows a detailed view of the circle region 1E of FIG. 1C.
FIG. 1F shows a detailed view of the circle region IF of FIG. 1D.
FIG. 2 shows a fastener extraction tool with a spoon-shaped profile in an embodiment of the present invention.
FIG. 3 shows a fastener extraction tool with striking surfaces in an embodiment of the present invention.
FIG. 4 shows a fastener extraction tool with splayed tips in an embodiment of the present invention.
FIG. 5 shows a fastener extraction tool with a spring system in an embodiment of the present invention.
FIG. 6 shows a fastener extraction tool with compound pivots in an embodiment of the present invention.
FIG. 7 shows a nail extraction tool with a chisel handle in an embodiment of the present invention.
FIG. 8A shows a cut away side view of a nail extraction tool with a gripping surface extending to the tip in an embodiment of the present invention.
FIG. 8B shows a top view of the embodiment of FIG. 8A.
FIG. 9 shows a fastener extraction tool with a straight gripping section and a cutter in an embodiment of the present invention.
FIG. 10A shows a side view of a half of a fastener extraction tool with a cutter in an embodiment of the present invention.
FIG. 10B shows a detailed view of the circle region 10B of FIG. 10A.
FIG. 11 shows a side view of a fastener extraction tool with a straight handle in an embodiment of the present invention.
FIG. 12 shows a top view of a fastener extraction tool with concave-shaped forward jaws in a closed position in an embodiment of the present invention.
FIG. 13 shows the embodiment of FIG. 12 with the forward jaws in an open position.
FIG. 14A shows a front view of the embodiment of FIG. 12.
FIG. 14B shows a detailed view of the circle region 14B of FIG. 14A.
FIG. 15A shows a front view of the embodiment of FIG. 12 in an open position.
FIG. 15B shows a detailed view of the circle region 15B of FIG. 15A.
FIG. 16A shows a cross sectional view along line 16A-16A of FIG. 13.
FIG. 16B shows a detailed view of the circle region 16B of FIG. 16A.
FIG. 17 shows a detailed perspective view of the tool head of the embodiment of FIG. 12 in an open position.
FIG. 18A shows a back view of a fastener extraction tool with rearward jaws having non-complementary surfaces in an embodiment of the present invention.
FIG. 18B shows a detailed view of the circle region 17B of FIG. 17A.
FIG. 18C shows a detailed view of the tool head of FIG. 18A in an open position.
FIG. 19 shows a side view of a fastener extraction tool with flat tool head top surfaces in an embodiment of the present invention.
FIG. 20 shows a top view of a fastener extraction tool with cold chisel tips in an embodiment of the present invention.
FIG. 21 shows a side view of a fastener extraction tool with handles extending out the back of the tool head in an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A tool closely related to the present invention is disclosed in commonly-owned U.S. Pat. No. 7,249,752, issued Jul. 31, 2007 to Foley, the disclosure of which is hereby incorporated herein by reference.
The following terms as used herein are defined relative to the tool or the workpiece. With reference to the tool, as shown in FIG. 1A, forward is defined as toward the left, rearward is defined as toward the right, upward is defined as toward the top of the page, and downward is defined as toward the bottom of the page. Also with reference to the tool, as shown in FIG. 1A, horizontal is a direction or plane perpendicular to the axis of the pivot 3, such as plane H-H, and vertical is a direction or plane perpendicular to the horizontal plane. With reference to a workpiece, upward is defined as away from the surface of the workpiece where the fastener is lodged and downward is defined as toward the surface of the workpiece where the fastener is lodged.
In contrast to prior art fastener extraction tools with jaws which grip a fastener from above, or from a vertical orientation, a fastener extraction tool of the present invention preferably operates by gripping the fastener with jaws from the side, or from a horizontal orientation. A horizontal orientation of the jaws allows a tool of the present invention to grip or re-grip the fastener no matter what the length of the fastener or the depth the fastener is embedded into a workpiece. A fastener extraction tool of the present invention also preferably grips the fastener at the extraction point where the fastener goes into the workpiece in order to provide a maximum amount of extraction of the fastener for a single pull before re-gripping the fastener to continue the extraction, if necessary. The horizontal orientation of the jaws also allows the tool to extract using the wide base of the tool head as the fulcrum, thereby spreading out the leverage force and minimizing damage to the workpiece during extraction.
FIGS. 1A through 1F depict a first embodiment of a fastener extraction tool 1 of the present invention. The fastener extraction tool 1 includes a tool head 2 which has two halves 2a, 2b. The halves 2a, 2b overlap in a central region where they are pivotally joined by a pivot 3. As can be seen in FIG. 1A, the overlap of the halves 2a, 2b at an interface 4 defines a substantially horizontal rotation plane H-H. Moving the halves 2a, 2b about the pivot 3 causes the tool head halves 2a, 2b to rotate relative to one another in the plane H-H shown in FIGS. 1A and 1C. Each half 2a, 2b of the tool head 2 has a portion extending forward of the pivot 3. The portions of the tool head halves 2a, 2b that are forward of the pivot 3 are tapered in at least one dimension such that the forward tips 5a, 5b of the tool head form a sharp implement that may be used to dig beneath the head of a fastener to extract it from the surface of a workpiece in which it is embedded.
The tool head 2 includes one or more pairs of gripping jaws for grasping and pulling fasteners. These gripping jaws are preferably formed from inward facing surfaces of tool head halves 2a, 2b. In the specific embodiment of the tool depicted in FIGS. 1A through 1F, there are two such pairs of jaws. A first pair of jaws 6 is located forward of the pivot 3 and includes two faces 6a, 6b. A second pair of jaws 7 is located rearward of the pivot 3 and includes two faces 7a, 7b. When the handles of the tool are brought together, the faces 6a, 6b and 7a, 7b of each pair of jaws come together along a longitudinal axis extending from the center front of the tool head 2 through the pivot 3 to the center rear of the tool head 2. In alternate embodiments, the fastener extraction tool may include only the forward pair of gripping jaws, only the rearward pair of gripping jaws, or more than two sets of gripping jaws.
The gripping jaws preferably include opposing gripping surfaces, which may be of any texture or material that allows the jaws to grip a fastener without slipping when held together by the user. Preferably, one or both of the pairs of jaws 6, 7 include a textured surface to better grasp a fastener. In the embodiment depicted in FIGS. 1C through 1F, this textured surface consists of grooves 11 oriented longitudinally along both faces of the pairs of jaws 6, 7. The grooves may have any suitable profile but are particularly effective when triangular in cross section as shown in FIGS. 1C through 1F. The grooves on each jaw may be arranged to mesh or to interfere when the jaws are closed.
The gripping jaws 6, 7 of the fastener extraction tool 1 do not primarily include cutting surfaces, such as those found in nippers and wire cutters, which may be of superficially similar appearance. Such cutting surfaces interfere with the goal of extracting a fastener. For instance, if one attempts to grip a fastener shaft with such cutting jaws and applies a force sufficient to facilitate its extraction, the blades of the tool simply cut through the fastener before it is fully extracted. The jaws of the present tool preferably have a sufficiently broad surface to prevent this undesirable cutting through of a fastener. Nonetheless, in alternate embodiments, to increase the possible uses of the tool, a secondary pair of cutting jaws may be included, or a portion of one or more pair of jaws may be provided with a sharp portion for cutting.
The fastener extraction tool 1 has two handles 8a, 8b extending rearward from the tool head 2, each handle extending from one half of the tool head 2a, 2b respectively. Moving the handles 8a and 8b together or apart causes the halves 2a, 2b of the tool head 2 to rotate about the pivot 3 and the pairs of gripping jaws 6, 7 to close and open. Preferably, at least a portion of the handles 8a, 8b is offset above the tool head. This portion includes a gripping portion for the user to apply a gripping pressure to the handles, which is transferred to the jaws for gripping the fastener. This offset allows leverage to be applied by exerting a downward force on the handles. As shown in FIG. 1A, the handles are preferably offset in a plane H′-H′, which is substantially parallel and located significantly above the plane H-H of the pivot. The handles may optionally include a surface coating 10 as shown in the figures. This surface coating is preferably a resilient material such as polymeric material that provides a surer grip for the user and makes the tool more comfortable to use. In addition, the handles are preferably sized and spaced to allow a comfortable grip of the tool by a user. In the depicted embodiments, the tool is configured for a single-handed grip, although in alternate embodiments of the present invention, such as those intended for heavier work, the handles may be sized and spaced for comfortable two-handed operation.
In the specific embodiment depicted in FIGS. 1A and 1B, the handles 8a, 8b extend rearward from the tool head 2 at an upward angle to a bend 9 beyond which the handles extend rearward in a direction substantially parallel to the plane H-H. It is to be understood that other shapes and arrangements of the handles may be used within the spirit of the present invention. The handles may extend upward for their entire length or may be curved or otherwise differently shaped than the depicted embodiments.
Preferably, a fastener extraction tool of the present invention has a longitudinally curved profile sloping upward toward either the front tip or the back end of the tool head on at least a portion of the bottom surface of the tool. This longitudinal curve aids in applying leverage to extract a fastener. FIG. 1A shows a plane A-A tangent to the underside of the forward jaws near the tip 5b. This plane A-A preferably forms an angle a with plane H-H, where angle a is preferably at least 45°. When the curved portion of the tool head bottom is used as the fulcrum to apply this leverage, it reduces the chance that the surface from which the fastener is being removed becomes damaged, since in such an arrangement, the fulcrum point of the tool moves in relation to the surface of the workpiece as the tool handles are moved upward or downward. This feature lowers the chance that a damaging force is applied at a particular point on the surface. The curve on the bottom of the tool head may encompass the entire length of the tool head, or it may extend for only a portion of the length. In the embodiment depicted in FIG. 1A, the tool head 2 includes a flat portion 12 rearward of the pivot, and only the front portion 13 of the profile is longitudinally curved. In the embodiment depicted in FIG. 2, the bottom 20 of the tool head is curved along its entire length, creating a spoon-like longitudinal profile. It is to be understood that the direction and extent of the curvature on the bottom of the tool head may be modified without departing from the spirit of the present invention.
Another preferred feature of a fastener extraction tool of the present invention is at least one striking surface designed to receive a blow from a hammer or similar tool. This feature allows a user to apply additional force to the tool to aid in extracting a fastener. In the embodiment shown in FIG. 3, a striking surface 30a is formed at the back of the tool head and another striking surface 30b is formed at the free end of one or both of the handles 32. The striking surface 30a at the back of the tool head is preferred in that it allows the user to drive the tool with a hammer or other striking tool with one hand in the direction of the forward tips while holding the handles with the other hand. With this arrangement, a hammer blow effectively applies the force necessary to drive the sharp tips of the tool head into a material, thereby allowing them to dig beneath and extract the head of an embedded fastener. The striking surface is particularly effective in combination with the claw-shaped portion discussed below in digging beneath a fastener head. The striking surface may have a bull's eye or similar pattern to aid the user in aiming. The striking surface may also have a non-metallic coating to reduce the noise of a metal hammer strike and to reduce sliding of the hammer in a glancing blow to the striking surface.
A number of additional features may be included on a fastener extraction tool of the present invention. Each of these features may be used in combination with any of the other features. The tool may include a claw-shaped portion at the forward end of the tool head. FIG. 4 illustrates a particular embodiment of this feature. The forward-most portion of each jaw is splayed outward slightly such that that the forward-portions of the jaws does not meet 40 when the gripping portion is closed as shown in FIG. 4. This splayed arrangement of the jaw tips 41, 42, in combination with the tapered shape of the forward jaws creates a feature similar to the claw on a common hammer or a tack puller. This claw-like feature allows a user to access and pry an embedded fastener upward so that it may be effectively grasped and removed by the gripping jaws. Preferably, the splayed portion of each jaw also includes an inward bevel 43, 44, such that the inward facing surface of the splayed portion has a narrow edge that may be slid under a fastener head. As shown in FIG. 4, this bevel may be inclined forward so that the edge narrows toward the tip of the tool, this arrangement tending to raise the fastener head as the claw is worked forward underneath it. Additionally, the splayed portions preferably taper to a shape that facilitates digging into wood or a similar material. In the embodiment of the tool depicted in FIG. 4, the tips of the claw taper to sharp points that readily penetrate wood or similar materials. In alternate embodiments, the tips may have other shapes, including, but not limited to, chisel-like ends, to perform a similar function.
A second feature that may be included on a fastener extraction tool of the present invention is a biasing element that biases the jaws to an open position. As shown in FIG. 5, a spring system 50 is disposed between the handles rearward of the pivot 3. Many other arrangements are known in the art for biasing the handles of pliers and similar tools. These arrangements include various types of springs disposed in a variety of ways. It is to be understood that any such mechanism may be adapted to the present tool without departing from the spirit of the present invention.
A third feature that may be included on a fastener extraction tool of the present invention is a compound leverage action between the tool head and the handles. Hand tools designed to apply heavy gripping or cutting forces often include a multi-part pivot assembly between their handles and the tool head, which multiplies a force applied to the handles of the tool. The embodiment of the present invention depicted in FIG. 6 shows one such compound leverage mechanism. In this embodiment, each half of the tool head is pivotally linked to one of the handles at a pivot 60, 62. The handles are pivotally linked to each other at a third pivot point 64, located forward of the first two pivots 60, 62. With the compound handles, moving the handles relative to each other through a given angle results in a smaller angular rotation of the tool head halves than with simple handles, but the force transmitted is correspondingly increased. Other compound leverage arrangements for hand tools such as sheet metal shears, bolt cutters, locking pliers, and the like are well known in the art, and it is to be understood that any such mechanism may be incorporated into the present invention.
A fourth feature that may be included on a fastener extraction tool of the present invention is a flat chisel-type end to at least one of the handles. FIG. 7 shows a chisel bar 70 at a terminal end of a handle 72. The chisel bar 70 is preferably formed integral with the handle 70. When the user is using the head of the tool, the chisel bar 70 is preferably covered by a cap 74 to prevent injury to the user. The cap may be made of the same material as the handle grips or of a harder material to prevent damage to the cap by the chisel bar. Chisel bars 70 may be located either on both handles or on just one handle and are preferably used to pry boards or other large building materials apart.
In an alternate embodiment of the present invention, FIG. 8A shows the gripping surfaces 80 of the forward jaws extending all the way to the tips 82 of the forward jaws. FIG. 8A is a cut-away view showing only half of the tool head. Although the gripping surfaces 80 are shown as having teeth formed of horizontally-oriented grooves 84, any surface topography or coating which provides enough friction or surface roughness to grab a fastener without slipping may be used within the spirit of the present invention. In this embodiment, as shown in FIG. 8B, the tips 82, 83 preferably meet when the jaws are closed, and the tops 86, 87 of the jaws are preferably substantially flat.
A fastener extraction tool of the present invention may be made from a variety of materials as long as they have the required strength and malleability to be produced in the shapes required. Preferably, the tool is made of steel or a similar high strength material. If the tool is intended for service where corrosion is a concern, the tool may be manufactured of corrosion-resistant materials such as stainless steel or bronze. The surfaces of the tool may optionally be treated by plating or by applying decorative or corrosion-resistant coatings or finishes typical of hand tools. The metal from which the tool is manufactured may be hardened or otherwise treated to ensure that the parts have the necessary strength and durability to perform their functions.
A fastener extraction tool of the present invention preferably provides a user with several options to remove fasteners: the best mode of using the tool depends on the type of fastener to be removed, the workpiece in which the fastener is embedded, and the location of the fastener relative to surrounding objects. For a fastener that is flush with or embedded below a surface, a typical first step involves accessing the head or shaft. As noted above, the forward portion of the tool head preferably includes a sharp implement to aid in this process. In use, this sharp implement penetrates the surface of the workpiece adjacent to a fastener head, and the tool is then forced toward the fastener to dig beneath the head of the fastener. If the fastener extraction tool includes the striking surface described above, a hammer may be used to apply additional force to drive the tips of the tool beneath the fastener. The claw-shaped portion at the tip of the forward jaws may also aid in this process, since it eliminates the need for the user to keep the jaws separated to accommodate the shaft of the fastener.
Once the forward tips of the tool head are inserted beneath a fastener head, downward movement of the handles causes movement about a fulcrum point on the bottom of the tool, and an upward force is imparted to the fastener, thereby raising it from the surface of the workpiece. If the fastener is short, this action may be sufficient to completely remove it from the workpiece. In cases where the fastener is longer, an additional step is necessary. To complete the removal of the fastener, the user may reposition the tool and use the gripping jaws of the tool head to firmly grasp the head or shaft of the fastener where it is exposed above the surface of the workpiece. When the forward jaws are used, the handles are forced downward while gripping the fastener to rotate the tool about a fulcrum point on the bottom of the tool head rearward of the forward jaws. This action further raises the fastener from the workpiece. For very long nails, this repositioning may be repeated to complete the extraction. If the fastener extraction tool includes a rear pair of jaws as described above, the fastener may be grasped with these jaws instead, in that case, the handles are moved in an upward direction so that the tool pivots about a fulcrum point forward of the rear jaws. The decision as to which pair of jaws to employ in a particular situation may depend on the type of fastener, the available surfaces against which the fulcrum acts, and the amount of space available in which to operate the tool. An assortment of fastener types may be extracted using the methods above, including, but not limited to, nails, staples, brads, tacks, pins and other similar hardware.
To increase the usefulness of the tool, a tool of the present invention may include cutter surfaces to allow the tool to cut wire, nails, or other similar materials. The cutter feature is preferably located in at least a portion of one pair of jaws of the tool. The cutter is preferably located in only a portion of the pair of jaws such that the jaws may be used both for gripping without cutting and for cutting depending on the placement of the object in the jaws. Referring to FIG. 9, in one embodiment, the cutter 90 is located in the forward extending portion of the tool head. In another embodiment of the present invention, the cutter is located in the rearward extending portion of the tool head.
FIG. 9 also shows handles 98a, 98b that are substantially straight along the length of the gripping section as an alternative to the curved ends shown in FIG. 1 through FIG. 8. As a second alternative, FIG. 11 shows handles 110 that extend substantially straight from one end to the other. Each of these handle shapes may be used advantageously depending on the required extraction force and geometry of the fastener/workpiece for the task at hand.
FIGS. 10A and 10B show a preferred design of a forward jaw of the present invention including a cutter. The front part of the jaw provides both a gripping feature and a cutting feature. The cutter 100 is located close to the pivot 103 to increase the cutting power of the sharp edge 101. The gripping surface 102 is located farther from the pivot 103 than the cutter to allow a greater lever action for raising a fastener gripped by the gripping surface.
FIG. 12 through FIG. 17 show a preferred design of the forward jaws of a fastener extraction tool of the present invention having concavely curved surfaces for gripping without cutting a fastener during extraction. In this embodiment, the forward jaws 120a, 120b preferably meet at the forward tips 122a, 122b when the tool is in a closed position, as shown in FIG. 12. The concave shapes 124a, 124b of the forward jaws allow them to grip while not cutting the fastener, in part due to the gap 140, as best seen in FIG. 14B, that is present between the jaws even when the tool is in a closed position. The forward jaws are preferably designed with a shallow concavity so that they grasp and score or nick but not cut through the fastener being extracted. In this embodiment, the forward jaws 120a, 120b are preferably concavely curved not only from the back to the forward tip 122a, 122b but also from the top to the bottom, as best seen in FIG. 15A through FIG. 16B. This concave shape of the gripping surfaces 150a, 150b helps the forward jaws 120a, 120b to maintain a grip on a fastener head being held in the forward jaws during extraction of the fastener. In this embodiment, the inward facing gripping surfaces of the forward jaw may have grooves, as shown in FIG. 8A and FIGS. 10A and 10B, or the gripping surfaces may be relatively smooth, as shown in FIGS. 15A and 15B.
FIG. 18A, FIG. 18B, and FIG. 18C show a preferred design of the rearward jaws of a fastener extraction tool of the present invention having non-complementary surfaces for gripping without cutting a fastener during extraction. Non-complementary surfaces, as used herein, are any surfaces which do not match up when the jaws are fully closed such that at least one gap is formed between the non-complementary surfaces when the jaws are fully closed. The left jaw 180a has a gripping surface 182 with a concave curved shape, and the right jaw 180b has a gripping surface 184 with multiple angled regions, as best seen in FIG. 18C. The non-complementary surfaces 182, 184 allow gaps between the jaws when the jaws are in a closed position to aid in gripping a fastener without cutting it during extraction. The non-complementary surfaces may be reversed such that the curved surface 182 is on the right jaw 180b and the angled surface 184 is on the left jaw 180a to provide the same function within the spirit of the present invention. Although FIG. 18A through FIG. 18C show a curved surface and a multi-angled surface, any pair of non-complementary surfaces without edges sufficiently sharp enough to cut a fastener in the rearward jaws may be used within the spirit of the present invention. Other shapes to the non-complementary surfaces include, but are not limited to, any non-complementary curved surfaces, any non-complementary multi-angled surfaces, and any combinations of curved and angled features. Although FIG. 18A through FIG. 18C show each gripping surface having the same contour from front to back, the gripping surfaces may also vary from front to back within the spirit of the present invention.
FIG. 19 shows a fastener extraction tool designed for demolition work in an embodiment of the present invention. In this embodiment, the top surfaces 190 of the tool head are substantially flat from the back of the tool head to the tips rather than curving upward toward the tips. This allows a greater force to be transmitted to the tips 192 when using the striking surface 30 to drive the tips 192 under a fastener head or into a workpiece.
FIG. 20 shows a fastener extraction tool with flat tips 200a, 200b on the forward jaws in an embodiment of the present invention. In this embodiment the tips 200a, 200b are formed to flare out as the tips of a cold chisel or the time of a regular flathead screwdriver. This alternative formation of the tips provides multi-purpose functions to the tool.
FIG. 21 shows a fastener extraction tool with handles extending out the back of the tool head in an embodiment of the present invention. In this embodiment, the tool is preferably forged with the handles 210 coming horizontally out the back of the tool head 212 and later bent upward 214 as shown in FIG. 21, which lowers the production cost of the tool. The handles 210 may be bent upward at about a 45-degree angle as shown in FIG. 21 or they may be additionally bent to the handle shape as shown in FIG. 1. Alternatively, the fastener extraction tool may be cast with the handles 210 coming out the back of the tool head 212 and extending upward as shown in FIG. 21 or FIG. 1 within the spirit of the present invention.
It is to be understood that the embodiments of the invention herein described are merely illustrative of the application of the principles of the invention. Reference herein to details of the illustrated embodiments is not intended to limit the scope of the claims, which themselves recite those features regarded as essential to the invention.
Patent Grant
7950627
