What I claim and desire to protect by Letters
1. A cutting tool including a body member, first and second wheels mounted on said body member and rotatable in a common plane, a plurality of radial teeth projecting from the periphery of the first wheel, and the periphery of the second wheel comprising at least one cutting element, the arrangement being such that, on pressurised rotation of said wheels over a sheet of material, the teeth of the first wheel perforate said sheet and the at least one cutting element of the second wheel scores along the line of said perforations formed by the first wheel.
2. A cutting tool as claimed in claim 1 in which the body member comprises an elongate shank, one end extent of which is bifurcated, the wheels being mounted one behind the other for rotation in the slot between the two branches so formed.
3. A cutting tool as claimed in claim 2 in which the first wheel projects forwardly beyond the one end of the shank.
4. A cutting tool as claimed in claim 2 in which the bifurcated one end extent of the shank is angled from the remainder of said shank.
5. A cutting tool as claimed in claim 1, a plurality of equi-spaced, substantially pointed teeth being formed around, to project radially-outwardly from, the periphery of the first wheel, the second wheel being of greater diameter than the first wheel.
6. A cutting tool as claimed in claim 5, a plurality of equi-spaced, equi-length arcuate cutting edges being provided around the periphery of the second wheel.
This invention relates to a tool for cutting, scoring or perforating preparatory to severing, thin sheets of paper, foil or like materials, and has particular, though not exclusive, application to the trimming of wallpaper, primarily after pasting and prior to drying.
The accurate trimming of the top and bottom edges, adjacent the ceiling (or picture rail) and skirting board respectively, of a slightly over-size length of wet-pasted wallpaper just hung on a wall, or a vertical edge at a corner of the wall often proves a difficult job.
Heretofore it has been common practice to mark or crease the required edge, whether straight or undulating, on the paper and subsequently attempt to cut along said mark or crease, usually with scissors. The resultant cut is often inaccurate, the wet paper often tends to tear, and particular problems occur at the corners of a room being decorated.
According to the present invention there is provided a cutting tool including a body member, for example an elongate shank, on which are mounted first and second wheels rotatable in a common plane, the first wheel having a toothed periphery and the periphery of the second wheel including one or more cutting or perforating elements, the arrangement being such that, on pressurised rotation of said wheels over a sheet of material, the teeth of the first wheel perforate said sheet and the cutting or perforating element or elements of the second wheel score along, cut through or further perforate the line of said perforations formed by the foremost wheel.
Conveniently one end extent of the shank is bifurcated, the wheels being mounted for rotation in the slot between the two branches so formed. Further, for ease of operation, said bifurcated end extent may be angled from the remainder of the shank.
In a preferred embodiment of the invention, the first wheel may be of relatively small diameter and may be provided around its circumference with a plurality, for example of the order of 15 to 20, of equi-spaced teeth, while the second wheel is of greater diameter, the periphery of said second wheel being notched to provide of the order of 12 equi-spaced, equi-length arcuate cutting edges. Alternatively, the periphery of said second wheel may be continuous to provide a continuous cutting edge.
By way of example only, an embodiment of the invention will now be described in greater detail with reference to the accompanying drawings of which:
FIG. 1 is a side view of the one end extent of the shank of a tool according to the invention, showing the two sheels;
FIGS. 2 and 3 are views in the directions of arrows A and B respectively of FIG. 1.
Referring to the drawings, the cutting tool includes an elongate shank of, for example, square transverse section, only the lower end extent 2 of which is shown. The other, upper end extent is provided with a handle (not shown) which forms an extension of the shank and which may be permanently secured to, or alternatively, may be removably secured to, said upper end extent. In the latter case, said handle may be adapted to receive therein any one of a plurality of other similarly-sectioned shanks comprising parts of screw-drivers and like tools.
For ease of use, the lower end extent 2 of the shank is angled, as seen in FIG. 1, from the rest of the shank and from the axis of the handle, said end extent 2 being bifurcated along its length to provide parallel branches 4, 6 and an intermediate slot 8 as best seen in FIG. 3.
A pair of spindles 10, 12, one adjacent the front and one adjacent the rear of said end extent 2, are fixedly secured to extend between the branches 4, 6, a pair of bushes 14, 16 being mounted to be rotatable on said spindles 10, 12 respectively within the slot 8.
Two co-planar wheels, indicated generally at 18 and 20, are mounted one behind the other on the bushes 14, 16 respectively thereby to be freely rotatable on the spindles 10, 12 within the slot 8.
The foremost of these wheels, 18, extends beyond the front end of the slot 8 and includes a body part 22 of relatively small diameter, typically of the order of 10mm, and of width substantially equal to that of the slot 8. Formed around the periphery of said part 22 are a plurality (in the illustrated embodiment 16 are shown) of equi-spaced radially-outwardly projecting teeth 24 the outer ends of which are substantially pointed.
The body part 26 of the rearmost wheel 20 is of relatively large diameter, typically of the order of 15mm, and of width substantially equal to that of the slot 8. Formed around the periphery of the body part 26 are a plurality (in the illustrated embodiment 12 are shown) of equi-spaced, radially-outwardly projecting teeth 28 each having an arcuate cutting edge 30. The cutting edges 30 of the wheel 20 and the pointed outer ends of the teeth 24 of the wheel 18 are all contained within a common plane.
The tool of the invention can be used in connection with any one of a number of sheet materials, but has particular application to the trimming of wet wallpaper. After a slightly over-size length of pasted wallpaper has been hung in position it is necessary to trim the upper and lower edges. The described tool facilitates such trimming. The two wheels 18, 20 are pressed against the paper and the tool is pushed along so that said wheels rotate, one after the other, along the line defining the required edge. As the tool is moved along said line, the teeth 24 of the rotating wheel 18 perforate the paper, the cutting edges 30 of the teeth 28 of the following wheel 20 then scoring the paper along the line of said perforations. The surplus paper can then readily be pulled away from the main length along this pre-perforated and pre-scored line, thus leaving an accurate edge, whether straight or undulating, to said length.
As mentioned above, the front wheel 18 projects beyond the front end of the shank of the tool thus enabling said wheel to be used in corners.
In a further embodiment of the invention, the cutting edge of the wheel 20 is continuous.
Clearly the tool of the invention can be used to prepare vertical edges as well as substantially horizontal edges.