GB2433048A

GB2433048A - Hand tool with wedge-shaped recesses

Info

Publication number: GB2433048A
Application number: GB0624300A
Authority: GB
Inventors: Charles Whitfield; Robert Townsend; Graham Godfrey
Original assignee: Carl Kammerling International Ltd
Current assignee: Carl Kammerling International Ltd
Priority date: 2005-12-06
Filing date: 2006-12-05
Publication date: 2007-06-13
Anticipated expiration: 2026-12-05
Also published as: DE102006006462A1; DE202006014527U1; GB2433048B; GB0624300D0; IE20060886A1; IE86070B1

Abstract

A hand tool 10 comprises two parts 11, 12 connected together by a pivot 16. Each part has an operative portion provided with a receiving recess 28, 29 that extends across its whole thickness. Each recess is generally wedge-shaped in cross-section, with slanting generally flat opposite sides (28a, 29a, fig 4) extending from an outer surface of the operative portions which faces the other of the two operative portions to a generally flat base (28c, 29c, fig 4). Each operative portion may be provided with a through hole 18 positioned to be in alignment when the hand grips are open (fig 3), and which can be used to shear a bolt upon closing of the handles.

Description

Hand tool The present invention relates to a hand tool comprising two

parts connected together by a pivot so that the two parts can be pivotally moved relative to one another about the pivot axis, respective portions of the said parts on one side of the pivot constituting hand grips, and respective further portions of the said parts which are closer to the pivot than the hand grips constituting operative portions.

An aim of a first aspect of the present invention is to provide a hand tool that can readily and effectively facilitate an electrical connection between electrical conductors.

In accordance with the first aspect of the present invention, this aim is addressed by the provision of a hand tool having the construction set out in the opening paragraph of the present specification, in which each of the said two operative portions is provided with a receiving recess, which extends across the whole thickness of the operative portion, the receiving recess being located opposite and adjacent to the receiving recess in the other of the said two operative portions when the hand tool is in a closed position so that the two recesses can together receive a wire end, the recess in cross-section being generally wedge-shaped, with slanting generally flat opposite sides extending from an outer surface of the operative portion which faces the other of the two operative portions to a generally flat base of the recess, so that the sides are closer together at the base than they are at the said outer surface.

This design element makes it possible to use the hand tool for bending the end of a wire. This makes it possible, for example, after stripping the insulation from the wire, to bend it to such an extent that the wire will be provided with a V-shaped end. This V-shaped end is then placed with the free end of the wire into one of the receiving recesses and with the remainder into the other receiving recess. By bringing the hand tool into a closed position, the two wire ends are bent towards each other, resulting in the free end being in close contact with the remaining wire. In this way, an excellent connection can be obtained at the contact point.

Advantageously, the operative portions have respective planar surfaces which are adjacent to one another and which define a shearing plane, and each operative portion has at least one through-hole which extends through it parallel to the pivot axis, which opens at one end in the said planar surface of the operative portion, and which is defined by a cylindrical internal surface of the operative portion, the through- holes being so positioned that they are in alignment with one another when the hand grips are in an open position, enabling an elongate member such as a bolt to be inserted into the through-holes and subsequent pivotal movement of the parts about the pivot which brings the hand grips closer together, by the user gripping the hand grips, to shear the elongate member into two parts at the shearing plane.

As a result of the through-holes being located closer to the pivot than the hand grips and as the through-holes are aligned with each other when the hand tool is in an open position, relatively large steel rods or bolts can easily be cut in two or shortened, at right angles to their longitudinal axis.

Furthermore, a tool incorporating an arrangement of this type is required for installation work where building components are to be fixed using bolts which are too long and which must therefore be shortened. Such bolts can easily be shortened by inserting them into the through-holes, without causing any damage to the threads.

For this purpose, it is recommended that the bolts should be of a diameter which is only slightly smaller than the diameter of the through-holes.

Hitherto such shearing of bolts has been accompanied by a degree of bending before the bolt is broken in two, with consequent damage to any screw thread on the bolt and with consequential burrs at the ends of the two parts of the broken bolt.

It is an aim of a second aspect of the present invention to provide a hand tool which is less susceptible to this problem.

Accordingly, the second aspect of the present invention is directed to a hand tool having the construction set out in the opening paragraph of the present specification, in which the operative portions have respective planar surfaces which are adjacent to one another and which define a shearing plane, and each operative portion has at least one through-hole which extends through it parallel to the pivot axis, which opens at one end in the said planar surface of the operative portion, and which is defined by a cylindrical internal surface of the operative portion which cylindrical internal surface has a length which is at least one and a half times its cross sectional diameter, the through-holes being so positioned that they are in alignment with one another when the hand grips are in an open position, enabling an elongate member such as a bolt to be inserted into the through-holes and subsequent pivotal movement of the parts about the pivot which brings the hand grips closer together, by the user gripping the hand grips, to shear the elongate member into two parts at the shearing plane.

During the shearing process, the bolts are held securely and exactly at right angles to the shearing plane, without any bending or slant in the cutting line occurring at the shearing plane. This is of special importance in the case of machine screws, as with such screws nuts may be added later, or they may be screwed into a threaded hole. The specific design of the through-holes which includes a shearing edge ensures a safe and reliable shearing action, even after long use, as the surfaces at the shearing plane of the hand tool can be made exceptionally hard. The cylindrical design of the through-holes, specifically in relation to the area of the shearing edge, means that the part to be sheared or cut is held exactly in place.

S It is especially advantageous, if the through-holes are provided with chamfers at their ends further from the shearing plane.

This chamfered design permits the through-hole to be shaped in such a way that it can be cylindrical for almost the whole of its length, whilst having an end part of the through-hole shaped to facilitate easy insertion of the bolt or other article to be severed.

It is advantageous for the hand tool to be capable of multiple uses, for example it should not be necessary for several tools to be used when carrying out installation work for which the hand tool is intended.

Furthermore, its design should be simple and it should be reasonably cheap to produce.

Advantageously therefore, each operative portion has a cutting edge on the opposite side of the pivot to the hand grips, in which the respective cutting edges of the said two parts touch when the hand grips are in a closed position, whilst, when hand grips are in the said open position viewing the hand tool in a direction along the pivot axis, the two cutting edges face each other in a V-position, the through-holes being on the same side of the pivot as the hand grips.

It is preferable that the two cutting edges of the hand tool have at least two insulation stripping notches for stripping the insulation of insulated wire ends when the hand tool is in a closed position.

In this way provision is made in a simple manner for stripping insulation from insulated wires, whilst at the same time the cutting function of the hand tool is not affected in any way. However, its range of application is extended in this way.

Positioning the through-holes below the pivot or centre pin also makes it possible to make good use of the area created in the case of an angled design of the said two parts of the hand tool, as a result of which there is no need to reduce the length of the cutting edges.

This is advantageous for users, as, on one hand, they can sever the wire with the cutting edges, and on the other hand, and in addition, they can make a connection with a connector.

It is especially advantageous, if the two hand grips are sheathed in respective insulating sleeves having two stepped safety projections respectively located in adjacent positions, whereby, when the hand tool is in a closed position, one safety projection is positioned beneath the other safety projection. In this way, protection is provided vis--vis the actual head portion of the hand tool, in such a way that parts of fingers are protected from being crushed beneath the pivot of the hand tool. Additionally the stepped safety projections keep the fingers at an adequate distance from the bare metal of the hand tool to reduce risk of electrocution An example of hand tool embodying the present invention will now be described in greater detail with reference to the accompanying drawings, in which:-Figure 1 is a front view of an example embodiment of hand tool in accordance with the present invention, in a closed position; Figure 2 is a front view of portions of the hand tool shown in Figure 1, in a closed position; Figure 3 is a front view of the portions shown in Figure 2, in an open position; Figure 4 is a front view of the portions shown in Figures 2 and 3, in a slightly open position; and Figure 5 is a sectional view of the portions of the hand tool shown in Figure 3, along the line V-V thereof.

Figures 1 to 5 show a hand tool 10 comprising a side cutter. It comprises two parts or plier halves 11, 12, each having an angled portion 13, which acts as part of a bridging portion between a hand grip portion 14 of the plier half 11, 12 and a head portion 15. The head portion 15, the angled portion 13, and a further portion of each plier half between the angled portion 13 and the hand grip portion 14 together constitute an operative portion of the plier half. Adjacent to its angled parts 13, the side cutter is provided with a centre pin 16, which acts as a pivot connecting together the two plier halves 11, 12 so that they can be moved pivotally relative to one another.

Each head portion 15 is provided with a cutting edge 17. The two cutting edges of the two plier halves touch in a closed position of the hand tool, whilst they are separated from each other in an open position. Beneath the centre pin 16, yet close to it (see Figure 3 and Figure 4), the two plier halves 11, 12 are both provided with respective through-holes 18. The through-hole 18 of the first plier half 11, is, when the hand tool 10 is in its open position, in alignment with the through-hole 18 of the second plier half 12. It should be mentioned at this point that the two respective adjacent ends of the two through-holes 18 open onto adjacent planar surfaces 19 of the plier halves which define a shearing plane. The transition from the inner surface of the through-hole to the planar surface is a sharp right angle, providing a sharp shearing edge.

When the hand tool 10 is in its open position, a bolt can be inserted into the through-holes 18. For this reason, each through-hole 18 is defined by a smooth cylindrical internal surface of the plier half 11 or 12, and should be of the same diameter as that of the bolt or of only very slightly greater diameter than that of the bolt. The length of the cylindrical internal surface of each through-hole 18 should be at least one and a half times its cross sectional diameter. In the example illustrated in the drawings, the diameter of each through-hole 18 is substantially 3.39mm, and its length is substantially 5.5mm. Thus in this case it length is S substantially 1.62 times its cross sectional diameter.

As the pliers are being closed, a clean cut is obtained in the shearing plane 19, whereby the external thread of the bolt will not be damaged.

At a position further from the pivot 16 than the through-holes 18, on the same side of the pivot 18 as the through-holes 18, and viewing the hand tool 10 from the front, there are provided two prismatic receiving recesses 28 and 29, located respectively in the plier halves 11 and 12 and constituting a bending device 32 of the hand tool 10. The prismatic wedge-shaped receiving recesses 28, 29 extend over the entire thickness of the plier halves 11, 12. Thus each recess 28, 29 as viewed from the front of the tool as in Figure 6, or in cross-section, is defined by opposite slanting generally flat sides 28a, 29a which extend from an outer surface 28b, 29b of the plier half 11, 12 that faces the other plier half, to a generally flat base 28c, 29c of the recess 28, 29, so that the sides 28a, 29a are closer together at the base 28c, 29c than they are at the outer surface 28b, 29b. The recesses 28, 29 serve as receiving recesses which provide locations for receiving wire ends.

One wire, which has already been stripped of its insulation, is initially pre-bent into a V-shape within the area of the cutting edge 17, following which the free end of the wire is placed in the receiving recess 28, with the remaining part of the wire being placed in the receiving recess 29, so that this action will always be S carried out with the hand tool 10 still in its open position. When the hand tool 10 is gripped and thus moved into its closed position, the free end of the wire is then bent onto the remaining wire, whereby the free end will then be located in a position which is in an opposite direction of precisely 180 to the remaining wire. A bent end of this type is especially advantageous when contact points are to be connected, as it facilitates secure connection.

It should also be mentioned that the hand grips 14 of the plier halves 11 and 12 are sheathed in respective insulating sleeves 34 covering the hand grips 14, with the insulating sleeve incorporating a slip-guard 35 in the direction of the head portion 15. This slip-guard 35 also acts as a support during the operation of the hand tool 10. In addition, both insulating sleeves 34 of the hand tool 10 are provided with two stepped safety projections 40, 41, which are both designed in such a manner that they are located opposite the stepped safety projections 40, 41 of the insulating sleeve 34 of the other plier half. On each insulating sleeve 34, the safety projection 41 is below and offset from the safety projection 40. As a result, when the hand tool 10 is gripped and thus moved into its closed position, the safety projection 40 of the insulating sleeve 34 of the plier half 11 is placed onto the safety projection 41 of the insulating sleeve 34 of the other plier half 12.

In Figure 5, the stepped design of the safety projections 40, 41 of the plier half 12 can be more clearly discerned.

The safety projection 41 of the insulating sleeve of the plier half 11 engages, in the closed position of the hand tool 10, beneath the safety projection 40 of the insulating sleeve of the other plier half 12, and the safety projection 41 of the plier half 12 engages beneath the safety projection 40 of the plier half 11. As the safety projections extend towards each other, protection is obtained when the hand tool 10 is gripped and thus moved into its closed position, and this ensures that a finger or hand of the user is protected from being crushed during the closing action.

It should also be pointed out that, as is clear from Figure 4, the safety projections 40 and 41 of the two plier halves 11, 12 already overlap before the hand tool is in its fully closed position. It is no longer possible for fingers to slip into the operative region of the hand tool 10 when the latter has been gripped to move it into its closed position.

At each head portion 15 of the plier halves 11, 12, a cutting edge 17 is provided, the two cutting edges 17 being provided with two pairs of insulation stripping notches 26 at their ends closer to the pivot or centre pin 16, whereby these notches 26 form two generally circular apertures when the hand tool 10 is in its closed position. Thus, these two apertures of different diameter can be used to remove insulation sheaths from wires of different diameters. When the hand tool 10 18 opened again, the insulation stripping notches 26 are separated in such a manner that there is half of the insulation sheath at each of the two cutting edges 17.

Figure 3 shows the hand tool 10 in the corresponding open position. The two plier halves 11 and 12 with their angled parts 13 can be clearly seen, where, as a result of the angular shape of the angled parts 13, the left plier halt 11 turns into the right part of the head portion 15 incorporating the cutting edge 17, whilst the right plier half 12 turns into the left part of the head portion 15, which results in the creation of an approximately V-shaped opening, where the sections or wires to be separated can be placed. As can also be seen, the two plier halves 11, 12 are pivotably movable relative to one another about the pivot or centre pin 16.

It should also be pointed out that the head portion 15 is angled in such a way that the cutting edges 17 are positioned in a V-shaped arrangement with respect to one another.

In the position shown in Figure 3, the two through-holes 18 of the plier halves 11, 12 are in alignment with one another. The wedge-shaped notches or recesses 28 and 29 are spaced apart in this position.

In Figure 5, the angled part 13 of the plier half 11 can be seen, with the angled part having a hole 27, in which the centre pin of the pivot 16 is located. Beneath the hole the two through-holes 18 are located and are in alignment with each other.

A head portion 15 is shown with one cutting edge 17.

As shown in this sectional representation, the head portion 15 is slightly inclined in a direction towards the centre pin 16 so that the greater part of it is on one side of the cutting edge 17. This cutting edge 17 is provided with the two insulation stripping notches 26.

The lower insulation stripping notch 26 has a larger diameter than the upper notch 26.

As already mentioned, the illustrated embodiment represents only an example of the reduction of the present invention to practice. The invention is in no way limited to this embodiment. On the contrary, several other modifications and applications are possible. For instance, it would be possible to move the insulation stripping notches even closer to the centre pin which would mean that they would virtually form the ends of the cutting edges. On the other side of the centre pin, a pair of differently sized bending devices could be spaced apart, so that there are two differently sized wedge-shaped recesses or notches in each plier part.

Also, a second pair of through-holes could be provided, adjacent to but of a different diameter from the illustrated pair of through-holes 18, the second pair being brought into alignment with one another at a different degree of opening of the hand tool 10 or at the same degree of opening. This facilitates the shearing of bolts of different respective diameters by the same tool.

Indeed, the hand tool could be provided with many such pairs of differently sized through-holes.

Claims

Claims: 1. A hand tool comprising two parts connected together by a

pivot so that the two parts can be pivotally moved relative to one another about the pivot axis, respective portions of the said parts on one side of the pivot constituting hand grips, and respective further portions of the said parts which are closer to the pivot than the hand grips constituting operative portions, characterisad in that each of the said two operative portions is provided with a receiving recess, which extends across the whole thickness of the operative portion, the receiving recess being located opposite and adjacent to the receiving recess in the other of the said two operative portions when the hand tool is in a closed position so that the two recesses can together receive a wire end, each recess in cross-section being generally wedge-shaped, with slanting generally flat opposite sides extending from an outer surface of the operative portion which faces the other of the two operative portions to a generally flat base of the recess, so that the sides are closer together at the base than they are at the said outer surface.

2. A hand tool comprising two parts connected together by a pivot so that the two parts can be pivotally moved relative to one another about the pivot axis, respective portions of the said parts on one side of the pivot constituting hand grips, and respective further portions of the said parts which are closer to the pivot than the hand grips constituting operative portions, characterjeed in that the operative portions have respective planar surfaces which are adjacent to one another and which define a shearing plane, and each operative portion has at least one through-hole which extends through it parallel to the pivot axis, which opens at one end in the said planar surface of the operative portion, and which is defined by a cylindrical internal surface of the operative portion the length of which cylindrical internal surface is at least one and a half times its cross sectional diameter, the through-holes being so positioned that they are in alignment with one another when the hand grips are in an open position, enabling an elongate member such as a bolt to be inserted into the through-holes and enabling subsequent pivotal movement of the parts about the pivot which brings the hand grips closer together, by the user gripping the hand grips, to shear the elongate member into two parts at the shearing plane.

3. A hand tool according to claim 1, characterjged in that the operative portions have respective planar surfaces which are adjacent to one another and which define a shearing plane, and each operative portion has at least one through-hole which extends through it parallel to the pivot axis, which opens at one end in the said planar surface of the operative portion, and which is defined by a cylindrical internal surface of the operative portion, the through-holes being so positioned that they are in alignment with one another when the hand grips are in an open position, enabling an elongate member such as a bolt to be inserted into the through-holes and enabling subsequent pivotal movement of the parts about the pivot which brings the hand grips closer together, by the user gripping the hand grips, to shear the elongate member into two parts at the shearing plane.

4. A hand tool according to claim 2 or claim 3, characterjged by the provision of a chamfer at that end of each through-hole which is further from the shearing plane.

5. A hand tool according to any preceding claim, characterjsed in that each operative portion has a cutting edge on the opposite side of the pivot to the hand grips, wherein the respective cutting edges of the said two parts touch when the hand grips are in a closed position, whilst, when the hand grips are in the said open position viewing the hand tool in a direction along the pivot axis, the two cutting edges face each other in a V-position, the through-holes being on the same side of the pivot as the hand grips.

6. A hand tool according to claim 4, characterised in that the two cutting edges of the hand tool have at least two insulation stripping notches, for stripping the insulation of insulated wire ends when the hand tool is in a closed position.

7. A hand tool according to any preceding claim, characterised in that the two hand grips are sheathed in respective insulating sleeves having two stepped safety projections respectively, located in adjacent positions, whereby, when the hand tool is in a closed position, one safety projection is positioned beneath the other safety projection.

8. A hand too], substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.