GB2181983A

GB2181983A - Shears

Info

Publication number: GB2181983A
Application number: GB08612023A
Authority: GB
Inventors: Frederick Booth
Original assignee: Keeton Sons and Co Ltd
Current assignee: Keeton Sons and Co Ltd
Priority date: 1985-10-11
Filing date: 1986-05-16
Publication date: 1987-05-07
Also published as: GB8525157D0; GB2181983B; GB8612023D0

Abstract

Hand shears for cutting cladding panels comprise an anvil 2 with a cutter blade 3 pivoted thereon, the edge of the anvil towards the blade and the cutting edge on the blade being profiled to suit the profile of the panel to be cut, and the cutting edge on the blade being convexly curved, the arrangement being such that as the panel is cut, a cutting projection 8 on the blade traverses completely a respective indentation 6 on the anvil before the next succeeding cutting projection commences its traverse across the next succeeding indentation on the anvil, and with any point of the cutting edge on a projection over its full periphery in contact with a corresponding point on a trough of a panel being cut, the angle of inclination of the cutting edge at that point is at an acute angle to the angle of inclination of the panel at that point. <IMAGE>

Description

SPECIFICATION Shears This invention relates to shears.

In the construction industry, there is the widespread use or metal cladding or construction panels which have a profiled section such as a generally square wave-form shape in cross-section. Traditionally, such panels are supplied to a standard length and width, and, particularly as to their length need to be cut, on site to a required size.

Traditional methods of cutting such as sawing and cropping inevitably generate distortions at the cut edges and which can cause varying degrees of difficulty in the subsequent assembly of a cut panel, exacerbated by the fact that it is frequently impractical or impossible to provide purpose-built cutting equipment on site, and cutting must be effected with appropriate hand tools.

The object of the present invention is to provide a hand operated shear for cutting panels of the type described and where a clean cut across the width of such panels can substantially be guaranteed.

According to the present invention, a hand operated shear for profiled sheet material comprises an anvil member and a blade member, said members being pivotally secured together at one end, and there being handle means on at least the blade member at the end remote from the pivot, the anvil member at its edge facing the blade member having a profile to conform substantially precisely to the cross-sectional shape of a profiled sheet to be cut, and the blade at its edge facing the anvil housing a convex arcuate configuration and being oppositely profiled to provide a number of projecting cutting formations spaced along its length corresponding to the number of depressions in the edge of the anvil, the arcuate configuration of the edge of the blade member so positioning each cutting projection that the cutting action of one projection across a corresponding depression in the anvil member is completed before a next succeeding cutting projection commences its cutting action across its corresponding depression, and each cutting projection being such that with any point of the cutting edge on the projection over its full periphery in contact with a corresponding point on the trough of a panel being cut, the angle of inclination of the cutting edge at that point is at an acute angle to the angle of inclination of the panel at that point.

Thus, with a panel of generally square wave-form, the cutting formations on the blade are of correspondingly generally square shape, with two side flanks and a bottom edge. In this case, as the blade is closed on to a panel located on the anvil, the side flank closer to the pivot between the blade and anvil of a projection contacts the uppermost corresponding corner of a trough in the panel, and when the angle of inclination of the side flank is at an acute angle to the side face of the trough, preferably 40 to 80. As cutting progresses down the side face of the trough in the panel, the relative angular disposition between the side flank of the cutting projection and the side face of the trough is maintained, until the bottom corner of the cutting projection meets the bottom face, and when the bottom edge of the cutting projection has the self-same angular disposition to the bottom face of the trough in the panel, i.e. preferably 40 to 80. Again, as cutting progresses across the bottom of the trough in the panel the same angular disposition of the bottom cutting edge to the bottom of the trough in the panel is maintained, until the opposite bottom corner on the cutting projection meets the opposite side face of the trough in the panel, and when yet again the same acute angular disposition of that side face of the trough of the panel and the corresponding side flank of the cutting projection is provided, and maintained as cutting progresses across that side face.The location and disposition of all the cutting projections on the blade are such that the above conditions are created as each trough of the panel is progressively cut.

Essentially the same conditions can be created with panels of sinusoidal wave-form. In this case, curved cutting projections are provided on the blade, such that with any point around the periphery of the cutting projection in contact with the corresponding point around the periphery of a curved trough in the panel, the respective tangents on the cutting projection and on the trough at those points are at an acute angle of, e.g. 40 to 80.

Preferably, both the anvil and the blade have their edge profiles formed by a flame cutting technique, the angle of the cut being such as to provide a flank on each profile set at an acute angle, to provide a distinct cutting edge particularly on the blade at its face of closest approach to the anvil.

The invention will now be described in greater detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of one embodiment of shears in accordance with the invention in the open position; and Figure 2 is a plan view of the shears of Figure 1 in the closed position.

In the drawings, a hand-operated shear 1 for profiled sheet material has an anvil member 2 to which a blade member 3 is pivotably secured at one end, the blade member having a handle 4 at the end remote from the pivot.

The anvil member 2 at its edge 5 facing the blade member has a profile incorporating a series of indentations 6 to conform substantially precisely to the cross-sectional shape of a profiled sheet (not shown) to be cut. Thus, with the blade member in its open position, a profiled sheet can be laid on the anvil member and be fully supported over its width.

The blade member 4 has an edge 7 facing the anvil, that is of generally arcuate configuration, the edge 7 being profiled oppositely to that of the edge of the anvil to provide a number of projecting cutting formations 8 spaced along its length and corresponding to the number of indentations 6 in the edge of the anvil.

By virtue of the generally arcuate configuration of the edge 7 of the blade member, the projecting cutting formations 8 each have an orientation such that as the blade member is pivotted to close on to the anvil member, the cutting action of a first projection across the corresponding depression in the anvil member is completed before the next succeeding projection commences its cutting action across its corresponding depression in the anvil member.

As illustrated in the drawings, the profiled sheet to be cut has a generally square waveform, and consequently the profiled edge 5 of the anvil member has a corresponding generally square waveform. In this case, the projecting cutting formations 8 on the blade member are similarly of generally square waveform to provide, on each, two side cutting edges 9 and a bottom cutting edge 10. The arrangement is such that with any point along the cutting edges 9 and 10 over the full periphery of a projection in contact with a corresponding point on the trough of a panel being cut, the angle of inclination of the cutting edge at that point is at an acute angle to the angle of inclination of the panel at that point.

Thus, after pivoting the blade member 4 to an open position and with a profiled panel located on the anvil, as the blade member 4 is closed on to the panel, the side cutting edge 9 closer to the pivot between the blade member and anvil member of a first cutting formation 8 contacts the uppermost corresponding corner of a trough in the panel, and when the angle of inclination of the cutting edge 9 is at an acute angle to the side face of the trough and preferably between 40 and 80. As cutting progresses down the side face of the trough, the relative angular disposition between the cutting edge 9 and the side face of the trough is maintained until the bottom corner of the cutting projection meets the bottom face of the trough in the panel, and when the bottom cutting edge 10 has the self-same angular disposition to the bottom face of the trough of the panel. As cutting progresses across the bottom face of the trough, the angular disposition between it and the bottom cutting edge 10 is maintained until the opposite bottom corner of the cutting formation 8 meets the opposite side face of the trough of the panel and when again the same acute angular disposition between the opposite cutting edge 9 and that side face of the trough of the panel is provided and maintained as cutting progresses across that side face.

To provide stability for the shears during use, it is preferred to provide at least two transverse feet 11 on the lower face of the anvil member. To provide mobility of the shears, two forwardly projecting arms 12 can be provided beyond the pivot between the blade and the anvil between which is rotatably mounted a transport wheel 13, the disposition of the arms 12 being such that with the feet 11 in contact with the ground, the wheel is spaced from the ground.

Claims

1. A hand-operated shear for profiled sheet material comprising an anvil member and a blade member, said members being pivotally secured together at one end, and there being handle means on at least the blade member at the end remote from the pivot, the anvil member at its edge facing the blade member having a profile to conform substantially precisely to the cross-sectional shape of a profiled sheet to be cut, and the blade at its edge facing the anvil housing a convex arcuate configuration and being oppositely profiled to provide a number of projecting cutting formations spaced along its length corresponding to the number of depressions in the edge of the anvil, the arcuate configuration of the edge of the blade member so positioning each cutting projection that the cutting action of one projection across a corresponding depression in the anvil member is completed before a next succeeding cutting projection commences its cutting action across its corresponding depression, and each cutting projection being such that with any point of the cutting edge on the projection over its full periphery in contact with a corresponding point on the trough of a panel being cut, the angle of inclination of the cutting edge at that point is at an acute angle to the angle of inclination of the panel at that point.

2. A hand-operated shear as in Claim 1, wherein the anvil member at its edge facing the blade member has a profile of generally square waveform, and the projecting cutting formations on the convexly arcuate cutting edge of the blade member are correspondingly of generally square waveform.

3. A hand-operated shear as in Claim 2, wherein the side and bottom cutting edges of the cutting projections and the corresponding flanks and base of the indentations in the anvil member are at an acute angle between 40 and 80 during the traverse of a cutting projection across a corresponding indentation.

4. A hand-operated shear as in Claim 1, wherein the anvil member at its edge facing the blade member has a profile of sinusoidal waveform and the cutting projections on the convexly arcuate cutting edge of the blade member are themselves convexly curved.

5. A hand-operated shear as in Claim 4, wherein the sinusoidal profile on the anvil member and the curved nature of the cutting projections are such that as a curved cutting projection traverses a respective trough in the sinusoidal profile on the anvil member, the respective tangents on the cutting projection and the trough at any point are at an acute angle of between 40 and 8 .

6. A hand-operated shear as in any of Claims 1 to 5, wherein stabilising feet are provided on the anvil member.

7. A hand-operated shear as in any of Claims 1 to 6, wherein a transport wheel is provided, which transport wheel is held clear of the ground when the shear is in its position for use.

8. A hand-operated shear substantially as hereinbefore described with reference to the accompanying drawings.