Apparatus for splitting wood into kindling
09833918 ยท 2017-12-05
Inventors
Cpc classification
B25G3/26
PERFORMING OPERATIONS; TRANSPORTING
International classification
B25D1/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A specialized wood splitting tool and handle attachment for a striking hand tool. The splitting tool uses leverage in addition to downward momentum of the cutting head to split wood. The metal handle and metal cutting head are preferably formed from a single piece of steel, in a perpendicular configuration similar to an adz. A splitting wedge blade within the handle exerts transverse shear forces to enhance splitting, and flat top surfaces of the cutting head and the handle near the joint provide a striking surface. A particularly advantageous handle extension attachment is disclosed that may be used with other striking hand tools as well as the wood splitting tool. A woodsman's hatchet that provides an additional blade perpendicular to a splitting wedge blade is also disclosed.
Claims
1. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define two side surfaces that converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions; and a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis.
2. The tool of claim 1, wherein the cutting head is adapted to transfer striking force nominally in a striking direction away from said longitudinal axis and passing through a midpoint of said first cutting blade, the handle shaft having a top tang and a bottom tang which extend away from the head nominally in a plane defined by the striking direction and the longitudinal axis and which terminate at respective distal ends thereof, the top tang having a laterally contoured lower surface and the bottom tang having a laterally contoured upper surface, the top tang and the bottom tang being spaced from one another in said plane, the tool further comprising an elongate handle extension having an attachment end, a grip end, a top portion and a bottom portion, the top portion of the handle extension having a laterally contoured upper surface complementary to the laterally symmetric contoured shape of the lower surface of the top tang extending longitudinally from the attachment end toward the grip end of the handle extension for receiving the lower surface of the top tang, and the bottom portion of the handle extension having a laterally contoured lower surface complementary to the laterally contoured shape of the upper surface of the bottom tang and extending longitudinally from the attachment end toward the grip end of the handle extension for receiving the upper surface of the bottom tang, the spacing between the top tang and the bottom tang being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
3. The tool of claim 2, wherein the upper surface of the top portion of the handle extension has a smoothly curved concave shape, the lower surface of the top tang has a smoothly curved convex shape, the lower surface of the bottom portion of the handle extension has a smoothly curved concave shape, and the upper surface of the bottom tang has a smoothly curved convex shape.
4. The tool of claim 2, further comprising one or more fasteners for securing the top tang to the handle extension and the bottom tang to the handle extension.
5. The tool of claim 1, wherein the cutting edge of the second cutting blade becomes closer to the first cutting blade as it becomes closer to the cutting head and defines a substantially smooth curve with increasing distance from the handle shaft.
6. The tool of claim 5, wherein the cutting head and the handle shaft are made of metal.
7. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define two side surfaces that converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions, the handle shaft further having a top tang and a bottom tang that extend away from the head nominally in a plane defined by the longitudinal axis of the handle shaft and the second cutting edge, the top tang and the bottom tang being spaced apart from one another in said plane; a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis; and an elongate handle extension, the handle extension having an attachment end, a grip end, a top portion and a bottom portion, a top groove formed in the top portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the top tang, and a bottom groove formed in the bottom portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the bottom tang, the spacing between the top groove and the bottom groove being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
8. The tool of claim 7, wherein the tangs and grooves have respective substantially laterally symmetric, contoured upper and lower mating surfaces.
9. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define two side surfaces that converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions, wherein the cutting edge of the second cutting blade becomes closer to the cutting head with increasing distance from the handle shaft, the handle shaft further having a top tang and a bottom tang that extend away from the head nominally in a plane defined by the longitudinal axis of the handle shaft and the second cutting edge, the top tang and the bottom tang being spaced apart from one another in said plane; a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis, wherein the second cutting blade is disposed between the first cutting blade and the second cutting blade; an elongate handle extension, the handle extension having an attachment end, a grip end, a top portion and a bottom portion, a top groove formed in the top portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the top tang, and a bottom groove formed in the bottom portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the bottom tang, the spacing between the top groove and the bottom groove being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
10. The tool of claim 9, wherein the tangs and grooves have respective substantially laterally symmetric, contoured upper and lower mating surfaces.
11. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define a substantially flat surface and two side surfaces that extend from the substantially flat surface to converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade and on the opposite side thereof as the substantially flat surface, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions, wherein the cutting edge of the second cutting blade becomes closer to the cutting head with increasing distance from the handle shaft, the handle shaft further having a top tang and a bottom tang that extend away from the head nominally in a plane defined by the longitudinal axis of the handle shaft and the second cutting edge, the top tang and the bottom tang being spaced apart from one another in said plane; a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis; and an elongate handle extension, the handle extension having an attachment end, a grip end, a top portion and a bottom portion, a top groove formed in the top portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the top tang, and a bottom groove formed in the bottom portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the bottom tang, the spacing between the top groove and the bottom groove being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
12. The tool of claim 11, wherein the tangs and grooves have respective substantially laterally symmetric, contoured upper and lower mating surfaces.
13. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define two side surfaces that converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions, wherein the cutting edge of the second cutting blade becomes closer to the cutting head with increasing distance from the handle shaft the handle shaft further having a top tang and a bottom tang that extend away from the head nominally in a plane defined by the longitudinal axis of the handle shaft and the second cutting edge, the top tang and the bottom tang being spaced apart from one another in said plane; a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis, wherein the cutting head and the handle are one unitary element; an elongate handle extension, the handle extension having an attachment end, a grip end, a top portion and a bottom portion, a top groove formed in the top portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the top tang, and a bottom groove formed in the bottom portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the bottom tang, the spacing between the top groove and the bottom groove being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
14. The tool of claim 13, wherein the tangs and grooves have respective substantially laterally symmetric, contoured upper and lower mating surfaces.
15. A tool for splitting wood or similar material, comprising: a cutting head that includes a first cutting blade; a handle shaft having a longitudinal axis that is substantially perpendicular to the first cutting blade, the handle shaft being joined to the cutting head so as to extend away from the cutting head and define two side surfaces that converge to form a second cutting blade on the same side of the handle shaft as the first cutting blade, the second cutting blade having an arcuate cutting edge, wherein the cutting edge of the second cutting blade becomes closer to the longitudinal axis with increasing distance from the cutting head, the second cutting blade being perpendicular to the first cutting blade so that the combined action thereof, when applied to the wood or similar material, first exerts shear forces substantially perpendicular to the first cutting blade and thereafter substantially perpendicular to said longitudinal axis so as to split the wood or similar material in two directions, wherein the cutting edge of the second cutting blade becomes closer to the cutting head with increasing distance from the handle shaft, the handle shaft further having a top tang and a bottom tang that extend away from the head nominally in a plane defined by the longitudinal axis of the handle shaft and the second cutting edge, the top tang and the bottom tang being spaced apart from one another in said plane; a third cutting blade disposed at an end of the cutting head opposite the end that includes the first cutting blade and being oriented substantially perpendicular to the first cutting blade, so that the tool may readily be rotated about the longitudinal axis so as to more readily exert shear forces to said longitudinal axis, wherein the cutting head and the handle shaft are made of metal; an elongate handle extension, the handle extension having an attachment end, a grip end, a top portion and a bottom portion, a top groove formed in the top portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the top tang, and a bottom groove formed in the bottom portion of the handle extension so as to extend longitudinally from the attachment end toward the grip end of the handle extension for receiving the bottom tang, the spacing between the top groove and the bottom groove being such that the attachment end of the handle extension may be inserted longitudinally into the handle shaft.
16. The tool of claim 15, wherein the tangs and grooves have respective substantially laterally symmetric, contoured upper and lower mating surfaces.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
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(27) Beyond mid-section 28, toward distal end 16, the cross section of handle shaft 14 widens near joint 19 to a shape that surrounds a broad, flat, top handle shaft striking surface 30 and a tapered secondary cutting blade 32 on the underside of handle shaft 14 to assist the cutting head 18 in splitting wood. Secondary cutting blade 32 structurally reinforces joint 19 to better withstand the forces generated when prying wood apart. The butt, or top surface, of cutting head 18 is also formed into a flat plane, providing a clean striking surface 34 opposite a primary cutting blade 36. In a preferred embodiment, striking surfaces 30 and 34 form a single, integrated flat plane. If primary cutting blade 36 should become lodged in the wood (because of the presence of knots, for example), removing cutting head 18 is made easier by the availability of the striking surfaces 30 and 34. By striking these flat surfaces with a mallet or other weighty object, an additional downward force is supplied to either finish splitting the wood by prying it apart, or to free cutting head 18 for another attempt.
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(34) In addition to the first cutting edge, the cutting head comprises a top portion 112, having a front face 114 and a back face 116 that are preferably essentially parallel to one another. Essentially is used herein to mean that, while not necessarily precisely parallel, the top portion would be understood to be of uniform thickness from front to back as a practical matter. However, it is to be understood that, while the use of a top portion having uniform thickness is desirable for cutting head strength, a non-uniform thickness may be used without departing from the principles of the invention. The cutting head also comprises a middle portion 118, having a front surface 120 and a back surface 122 that taper from the front surface 114 and back surface 116 of the top portion toward the first cutting edge 108. The cutting edge is formed to be sharp, as for example by grinding the bottom edge of the cutting head.
(35) Referring to
(36) Turning to
(37) It has been found that, while it is preferable for strength that the cutting head and handle be made of metal, such as steel, it is also preferable that the handle extension 106 be made of wood, or material having strength and resiliency characteristics similar to wood, such as suitable plastic, fiberglass or carbon fiber material, for example. The integral metal cutting head and handle also provide an advantage over other impact hand tools that employ a handle, typically made of wood, connected to a separate head having a hole, or eye, in which an end of the handle is inserted for attachment to the head. The advantage is that while an eye in the head will weaken the head's ability to withstand blows from the top, such as those that can be the result of using a hammer to drive the cutting blade further into wood, that is not the case with the integral head and cutting blade.
(38) In this second embodiment, the handle includes recesses 140 on both sides thereof, as shown by
(39) Turning now to
(40) In this case, the handle extension has a top groove 239 and a bottom groove 241 into which the top tang 215 and the bottom tang 217, respectively, fit so as to form a joint between the handle shaft 214 of the cutting head and the handle extension, as particularly shown in
(41) Preferably the fasteners 246 and 248 are threaded fasteners that slip through apertures 242 and 244, respectively, of the top tang 215, and through apertures 252 and 254, respectively, of the grooved portion 250 of the handle extension 206 and engage the apertures 260 and 262 of the bottom tang 217, having complementary threads, to firmly attach the handle extension 216 to the handle shaft 214. However, it is to be understood that other types of fasteners, including bolt and nut combinations as well as opposing wood screws could be used.
(42) The tang, groove and fastener interlocking attachment mechanism described above with respect to
(43) For examples, such devices include, but are not limited to, a mattock 300, comprising a mattock head 302 having a handle shaft 303 including top and bottom tangs 304 and 306, respectively, and a grooved handle extension 308 held in place by fasteners 310 and 312, as shown in
(44) Turning to
(45) Although certain embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a wide variety of alternative or equivalent embodiments or implementations calculated to achieve the same purposes may be substituted for the embodiments illustrated and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that embodiments in accordance with the present invention may be implemented in a very wide variety of ways. This application is intended to cover any adaptations or variations of the embodiments discussed herein.
(46) The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, to exclude equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only the claims that follow.