EP2687335A1

EP2687335A1 - Nail removal tool head and removal tool for nails

Info

Publication number: EP2687335A1
Application number: EP13151959.7A
Authority: EP
Inventors: Nigel Carr
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-07-17
Filing date: 2013-01-18
Publication date: 2014-01-22
Anticipated expiration: 2033-01-18
Also published as: EP2687335B1

Abstract

The invention provides a nail removal tool head comprising a tool head body having an end portion and a chisel front portion. The chisel front portion comprises two jaws which run together in a tapered slot towards a concave backside joint. The end portion comprises at least one drive hole, the hole axis of which runs substantially perpendicular to the direction of extension of the tool head body. The drive hole has a cross-section having a chamfered edge, the crosss-section being formed by a a coplanar superposition of a square shape, a first regular hexagon shape and a second regular hexagon shape. The chamfered edge is shaped according to the outmost edges of the coplanar superposition of the square shape, the first regular hexagon shape and the second regular hexagon shape.

Description

CROSS REFERENCE OF THE APPLICATION

The application claims benefit of the European patent application number EP 12 176 792 filed on 17th July 2012 .

FIELD OF THE INVENTION

The invention pertains to a nail removal tool head and a removal tool for nails and nail-like items, the removal tool having a nail removal tool head.

BACKGROUND TO THE INVENTION

Conventional claw hammers are used for extracting a nail, spike or pin from wood or other material. A claw hammer is useful where the fixed handle, or hammer shaft, provides leverage and thereby a mechanical advantage to defeat the resistance of the nail being extracted. Those hammers usually have a fixed handle, a club head fitted to one end of the handle, and a nail pulling claw fittted to the end of the handle next to the club head. The nail pulling claw has an associated convex fulcrum surface.
The difficulties with such a conventional claw hammer might be:

the fixed handle might obstruct or interfere with the ability to engage the claw of the hammer with the nail;
the fixed handle being permanently fixed to the claw has limited leverage moment for extracting nails;
a claw hammer being manufactured with the size of the claw being of a fixed size relative to the size of the fixed handle necessitates a fixed relationship thereby potentially limiting the mechanical advantage of leverage;
the fulcrum point of the leverage is affected by the club head geometry;
the commercial sizes of claw hammer and their relative sizes of claw are restricted according to commercial availability.

There have been several attempts to change the topology of claw hammers - however, improvements achieved by the state of the art have been hitherto either limited to adapt the conventional claw with a fixed handle construct or to form the tool with moving parts.
Document WO 1999/059780 A1 discloses a claw hammer head having a body, a neck extending from the front of the body and having a face, and a claw extending from the back of the body.
Document NL 9301607 extends the claw fulcrum to replace the club end.
Document US 4,216,808 discloses a semi-circular claw.
Document WO 1983/003568 A1 discloses an adjustable fulcrum hammer with a handle having a grip at one end, a head fixed about the other end and a fulcrum rod extending into the hollow of the handle through a bore in the head.
Document WO 2006/045035 discloses a tool having a head repositionably mounted to an end of an elongate handle.
Document EP 0 205 682 discloses a hammer head adapted to be fixed to a hammer shaft and fitted with a a claw for extracting nails from a work surface.
Document US 2,643,854 A1 and US 2,657,903 disclose an extendable ratcheted fulcrum.
Document NZ 208329 discloses pivoting handles.
Document US 6,298,512 B1 discloses a hinge pin and plastic clip remover which alternatively serves as hammer and pry bar. The remover has a V-notched pry ridge end, a transition shaft and a central shank serving as tool handle. The transition shaft includes a threaded hole for reception of a plurality of different tools.
Document US 7,367,545 B1 discloses a multi-purpose lever type tool having a notched pry claw connected to a handle. The pry claw is perforated with a nail pulling slot cut through the top and bottom sides of the pry claw.
Document US 2008/ 0217592 A1 discloses a hand tool bar for pulling nails and the like having a perforated pry end connected a a bar shank member.
Document US 6,913,246 B1 discloses a pry bar tool having a notched bar end and a bar shank portion including threaded holes for releasably fixing a bar handle to the tool.
Document US 7,628,382 B2 discloses a tool head member, for example a nail extractor, that may be indexably and releasably coupled to a handle member.
Document US 2004/ 0069978 A1 discloses a prying tool having a head portion and a handle portion, the handle portion comprising an aperture with a pre-determined polygonal shape to be mated with an appropriately shaped projection of a handle bar.
Thus, there is a need for an improved solution for exraction of nails or nail like items from a nail holding material which a) has no moving parts, b) is light weight and easy to store, c) provides better leverage, d) facilitates a detachable handle of any useful size and e) is simpler to fabricate/manufacture than the above.

SUMMARY OF THE INVENTION

Accordingly, a first aspect of the invention relates to a nail removal tool head, comprising a tool head body having an end portion and a chisel front portion. The chisel front portion comprises two jaws which run together in a tapered slot towards a concave backside joint. The end portion comprises at least one drive hole where the axis of that hole runs substantially perpendicular to the direction of extension of the tool head body. The drive hole has a cross section having a chamfered edge, the cross section being formed by a coplanar superposition of a square shape, a first regular hexagon shape and a second regular hexagon shape. The three shapes are superposed in such a way that the length between two opposite sides of the first regular hexagon shape is the length of a side of the square shape, the two opposite sides of the first regular hexagon shape coinciding with the two first opposite sides of the square shape, and that the length between two opposite sides of the second regular hexagon shape is the length of a side of the square shape, the two opposite sides of the second regular hexagon shape coinciding with two second opposite sides of the square shape. The chamfered edge is shaped according to the outmost edges fo the coplanar superposition of the square shape, the first regular hexagon shape and the second regular hexagon shape.
A second aspect of the invention relates to a removal tool for nails and nail like items, the removal tool comprising a nail removal tool head according to the first aspect of the invention, and a handle comprising engaging means releasably engaged with the drive hole of the nail removal tool head.
The invention is set forth and described with the characteristics of the invention in the claims. One main idea of the invention is to provide a removal tool head for the removal of nails, pins, spikes, bolts or other pin-shaped sharp objets having an elongated body portion serving as a frictionally engaged fastening means. The removal tool head includes a front end portion appropriately shaped to facilitate the removal of nails by means of leveraging the front end portion around a fulcrum located in an end portion of the tool head. The end portion includes a drive hole designed and manufactured so that the tool head can be engaged by a protruding engaging means of a socket wrench, a gripping handle or an Allen key. The fulcrum for leveraging the front end portion runs in parallel with the axis through the extension of the drive hole within the end portion.
According to the invention, the drive hole has a cross section which is chamfered to facilitate locating the engaging means in the drive hole so to provide proper torque transfer from the handle to the tool head.
Advantageous modifications and developments are set forth in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a schematic illustration of a perspective view on a nail removal tool head according to an embodiment of the present invention.
Figure 2 shows a schematic illustration of two exemplary tool handles which may be engaged with the nail removal tool head as shown in Figure 1 according to a further embodiment of the present invention.
Figure 3 shows a schematic illustration of an exemplary topology of the cross section of the drive hole of the nail removal tool head as shown in Figure 1 according to yet another embodiment of the present invention.

The drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of the description. The drawings illustrate the embodiments of the present invention and serve to explain the principles of the invention together with the description. Other embodiments of the present invention and many of the intended advantages of the present invention will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

DETAILED DESCRIPTION OF THE INVENTION

Although specific embodiments have been illustrated and described herein, it wil be appreciated by those of ordinary skill in the art that a variety of alternative and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. Generally, this application is intended to cover any adaptations or variations of the specific embodiments discussed herein.
Nail within the meaning of the invention may comprise any pre-shaped sharp object having an elongated body portion to be driven into and possibly through a work part in order to provide for frictionally engaged fastening of the work part to another component. In particular, nails may also include bolts, pins, spikes, brads, tacks, gibs, gudgeons, pegs and similar nail like fasteners. These terms may be used interchangeably within the sense of the invention.
With reference to Figure 1, a nail removal tool head comprises a tool head body 3 having a generally convex, in particular semi-circular, end portion 10 and a chisel front portion with two jaws 4 and 5. The tool head body 3 may be manufactured from any suitable material having the necessary strength and rigidity for its function as a nail removal tool head. In particular, the material may be resistant to corrosion, strong enough to be strikable and strong enough for withstanding extracting forces. The tool head will have sufficient strength so that it may be driven by impact to its end portion 10 into the material holding the nail to be extracted. For example, the tool head body 3 may be manufactured from metal, metal alloys, carbon fibres, hard plastic or compounds of these materials. The tool head body 3 may in particular be formed integrally, that is as a unary component. This allows the tool head to be easier and cheaper to be manufactured than a respective claw hammer intended for the same use.
The jaws 4 and 5 comprise respectively bevelled inner ridges 7 which run together in a V shaped notch or tapered slot 9. The tapered slot 9 ends in a generally concave backside joint 8. The front ends 6 of the jaws 4 and 5 are respectively bevelled or slanted towards their ends. The bevelled ridges 6 may for example be inclined at an angle 6a with respect to the line of extension running perpendicular to the direction of extension of the jaws 4 and 5.
The shape and dimansions of the jaws 4 and 5 and the corresponding tapered slot 9 may in particular be manufactured to facilitate putting the tool head into place for extracting a nail. The bevelled or slanted ridges 6 may allow the front end portion of the tool head body to be forced into the work part holding the nail to be extracted. The angle 6a of the bevelled ridges 6 of the jaws 4 and 5 may allow for access to spatially restricted places such as a corner. The bevelled inner ridges 7 of the jaws 4 and 5 and the tapered slot 9 may in combination have the function of guiding the chisel front portion of the tool head onto a nail to be extracted. The concave back portion 8 serves as a receptacle for the nail head.
The end portion 10 of the tool head includes an outer surface which may be convex. The end portion may comprise a drive hole 1 having an axis perpendicular to the direction of extension of the tool head towards the front portion. For example, the drive hole 1 may be configured as a through-hole or via into the end portion 10. It may be possible to form a recessed drive hole 1 from one side surface of the end portion 10, and another recessed drive hole 1 from the opposing side surface of the end portion 10. In this case, it may be particularly useful to form the different recessed drive holes 1 with different sizes in order to allow for different tool handles to engage the tool head.
The tool head does not necessarily have a permanently attached handle so that the tool head is easy to store, lighter than a functionally similar claw hammer, and can be brought into spatially restricted or confined places before the handle needs to be attached. In particular, the jaws 4 and 5 might be brought into engagement with a nail to be extracted before attaching a handle or gripping means to the tool head. The handle specifically may be attached in a piecemeal operation, in a confined space or just to pass a restriction on access to the nail.
The drive hole(s) 1 may be suited to engage protruding engaging means of a socket wrench, a gripping handle or Allen key. The fulcrum for leveraging the front end portion runs in parallel to the axis through the extension of the drive hole(s) 1 within the end portion 10. When a handle is applied in the drive hole 1, torque may be aplied to the handle, so that the tool head is pivoted around the fulcrum and the jaws 4 and 5 are continuously turned around the axis of the drive hole(s) 1. Any nail that is engaged in the concave back portion 8 of the tool head will thus be extracted from the material on which the bottom surface of the tool head is rested.
Figure 2 shows schematic illustrations of exemplary handles or engaging means. Figure 2(a) shows a ratchet socket wrench 11 having a protruding engaging means 12 with a substantially square cross section. The socket wrench 11 may for example include a ball bearing 13. Alternatively, as shown in Figure 2(b) the handle may comprise an Allen key 14 having a protruding end portion 15 of substantially hexagonal cross section.
Once engaged with the drive hole 1 of the tool head, the socket wrench 11 or Allen key 14 or any other handle with a return action such as a hexagon rod or a prying grip, a turning motion may be initiated for the tool head. Alternatively, the handle may be engaged and disengaged a number of times to allow a continuous arc of leverage. The handle may be engaged with the tool head, for example with an extension bar between the handle and the tool head. The tool formed by the tool head and the engaged handle may be capable of any degree of rotation driven in a constant and axial direction, since the bottom surface of the invention allows for turning motion along a large path of leverage.
The tool head might be used to withdraw the nail completely from the material by way of the unrestricted turning and the unrestricted turning moment provided by a ratchet socket wrench having a return action, or alternatively a socket wrench or other handle that is engaged and disengaged a number of times. The tool head and the corresponding size of the drive hole(s) 1 may be chosen freely scaled to any dimension depending on the size of nails to be extracted. For example, a larger version of the tool head may be used to extract tent pegs or the like.
Figure 3 shows a schematic illustration of an exemplary topology of the cross section 2 of the drive hole 1 of the nail removal tool head as shown in Figure 1. The cross section 2 may in particular be chamfered in a polygonal fashion in order to provide the chamfered inner surface 1a of the drive hole 1.
The dimensions of the cross section 2 may vary acording ot the desired functionality of the tool head. For example, the hexagonal shapes may be in accordance with a 9 mm (or 3/8") hexagonal Allen key 14 and so the square shape used may be dimensioned according to the desired engagement with a socket wrench 11. In the case of two drive holes 1 on opposite side surfaces of the end portion 10 of the tool head, the dimension of the two drive holes may be different in order to be able to engage the tool head with different handles which may be engaged with the respectively dimensioned hole accordingly.
The cross section 2 is formed by a coplanar superposition of a square shape 20, the first regular hexagon shape 21 and a second regular hexagon shape 22. The superposition of the different shapes is chosen in such a way that all superposed shapes have a coninciding centre of mass. The length between two opposite sides of the first regular hexagon shape 21 corresponds to the length of a side 20b of the square shape 20. With the coincidence of the centres of mass of the square shape and the first regular hexagon shape, two opposite sides of the first regular hexagon shape 21 coincide with two first opposite sides 20a of the square shape 20. This results in the formaton of two diametrically opposite vertices c of the first regular hexagon shape 21 that lie outside the perimeter of the square shape 20 at the two second opposite sides 20b of the square shape 20. Two sides of the first regular hexagon shape 21 intersect a respective second side 20b of the square shape 20 at points a and b, and the same two sides of the first regular hexagon shape 21 join outside of the square shape 20 at vertex c. This means that the points a, b and c form vertices of triangles 23b with sides A, B and C, wherein side A is the segment of the square shape side between a and b, side B is the segment of the first regular hexagon shape side between a and c, and side C is the segment of the first regular hexagon shape side between b and c.
Similarly, the length between two opposite sides of the second regular hexagon shape 22 corresponds to the length of a side 20a of the square shape 20, so that the two opposite sides of the second regular hexagon shape 22 coincide with two second opposite sides 20b of the square shape 20. In a manner analogous to that described for the first regular hexagon shape 21, this results in the formation of two diametrically opposite vertices c of the second regular hexagon shape 22 that lies outside the perimeter of the square shape 20 at the two first opposite sides 20a of the square shape 20, and hence in the formation of two more triangles 23a with sides A, B and C at the two first opposite sides 20a of the square shape 20.
The triangles are thus formed at each side of the suare shape 20.
This means that the cross section 2 of the drive hole 1 has four peaks formed from the B sides and C sides at the outside of the square shape 20 and the segments W, X, Y and Z of the first regular hexagon shape 21 inside the square shape 20 are removed. Similarly the inner segments of the second regular hexagon shape 22 inside the square shape 20 are removed, so that cross section 2 of the drive hole 1 comprises sixteen sides, with rotational symmetry of order four and four lines of reflection symmetry.
The cross section 2 of the drive hole 1 may extend in a linear fashion into the recess formed by the respective drive hole 1, either through the whole end portion 10 of the tool head body 3 or, in the case of two opposing drive holes 1, up to a predetermined depth in the end portion 10.
The shape of the cross section 2 is conveniently formed to receive square or heagonal engaging means alike, so that a great variety of commonly used socket wrenches 11 or Allen keys 14 may be used as gripping or torque handle for the nail removal tool head.
The chamfered edge 1a is shaped according to where one side surface of the end portion 10 should be joined to the outmost edges of the coplanar superposition of the square shape 20, the first regular hexagon shape 21 and the second regular hexagon shape 22; that is, the recess of the chamfered edge 1a corresponds to the shape of the perimeter of the drive hole 1 extended to the side surface of the end portion 10.
It is here stated that this invention shall not be limited in its applicaion to the details of construction and/or to the arrangement of the elements set out in the claims or description of the invention or illustrated in the mosaics; nor restricted to nails. The invention is capable of other embodiments and/or being practiced and/or carried out in other ways. It is also here stated that the choice of terminology employed herein is for the purpose of description and should not be treated as limiting.
With respect to the above description, it is intended that the optimum geometry for the pans of the invention, to include variations in size, material, shape, form, application and use are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings are intended to be encompassed by the present invention.
Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

Nail removal tool head, comprising:
a tool head body (3) having an end portion (10) and a chisel front portion;

the chisel front portion comprising two jaws (4) and (5) which run together in a tapered slot (9) towards a concave backside joint (8); and

the end portion (10) comprising at least one drive hole (1), the hole axis of which runs substantially perpendicular to the direction of the extension of the tool head body (3),

characterized in that the at least one drive hole (1) has a cross section (2) having a chamfered edge (1a), the cross section (2) being formed by a coplanar superposition of a square shape (20), a first regular hexagon shape (21) and a second regular hexagon shape (22), wherein the length between two opposite sides of the first regular hexagon shape (21) is the length of a side (20b) of the square shape (20), the two opposite sides of the first regular hexagon shape (21) coinciding with two first opposite sides (20a) of the square shape (20), wherein the length between two opposite sides of the second regular hexagon shape (22) is the length of a side (20a) of the square shape (20), the two opposite sides of the scond regular hexagon shape (22) coinciding with two second opposite sides (20b) of the square shape (20) and

wherein the chamfered edge (1a) is shaped according to the outmost edges of the coplanar superposition of the square shape (20), the first regular hexagon shape (21) and the second regular hexagon shape (22).
Nail removal tool head according to claim 1, wherein the two jaws (4, 5) comprise respectively bevelled inner ridges (7) as side portions of the tapered slot (9).
Nail removal tool according to claim 1 or 2, wherein the front ends of the two jaws (4, 5) are respectively bevelled or slanted towards their ends to form bevelled ridges (6).
Nail removal tool according to claim 3, wherein the bevelled ridges (6) are inclined at an angle (6a) with respect to the line of etension running perpendicular to the direction of extension of the two jaws (4, 5).
Nail removal tool according to one of the claims 1 to 4, wherein the end portion (10) includes two drive holes (1) recesed in respectively opposite side surfaces of the end portion (10).
Removal tool for nails and nail like items, comprising:
a nail removal tool head according to one of the claims 1 to 5; and

a handle (11; 14) comprising engaging means releasably engaged with the drive hole (1) of the nail removal tool head.
Removal tool according to claim 6, wherein the engaging means comprise protruding engaging means (12) having a substantially square cross section.
Removal tool according to claim 6, wherein the engaging means comprise a protruding end portion (15) of substantially hexagonal cross section.
Removal tool according to one of the claims 7 and 8, wherein the handle (11; 14) comprises a socket wrench (11) or an Allen key (14).