Cutting Guide

The invention relates to a cutting guide and more particularly to a cutting guide for use in making a cut in a flexible sheet member, such as a carpet. The cutting guide is of especial value when a neat and tidy seam or joint is to be provided between two portions of carpet. The invention also extends to a method of using the guide.

In my patent application PCT/GB 88/00805 Agents ref 2718 PCT, I have described and claimed a guide for use in making a cut in a flexible sheet member such as a carpet, the guide comprising a base having a substanitally flat upper surface portion, an elongate channel to receive a cutting device such as the blade of a knife, extending adjacent the upper surface portion, the flexible sheet being arranged in use to overlie the upper surface portion and the channel, wherein an inner side wall of the channel extends at an oblique angle to the upper surface portion and the cutting device in use is urged towards that inner side wall to produce a cut which is at an oblique angle to the plane of the sheet.

When the guide is used to form a seam between two portions of carpet, skill is required by the user to ensure that the cut edges are parallel to one another and are correctly spaced apart, so that when the guide is removed, the cut edges fall together and abut each other.

It is one object of the invention to avoid or minimize that problem.

According to one aspect of the invention, there is provided a guide for use in making a cut in two flexible sheet members such as carpets which are to be placed in edge to edge contact, the guide comprising a base having a substantially flat upper surface portion, an elongate channel extending adjacent the upper surface portion to receive the blade of a cutting device such as a knife, a side wall of the channel being at an oblique angle to the upper surface portion, wherein a substantially vertical wall portion extends longitudinally along the base substantially in vertical alignment with, and parallel to the mouth of the channel.

Preferably the base comprises an upper and a lower portion which include releasable interengaging means so as to be movable relative to each other in the direction of their length, the upper surface portion and the channel are located on the upper base portion, and the vertical wall is located on the lower base portion.

In another aspect of the invention there is provided a method of joining two portions of carpet or like sheet material in side-by-side relationship comprising the steps of:

placing a guide according to the invention underneath the margin of the first portion of carpet;

inserting the blade of a knife in the channel and urging the blade towards the oblique inner side wall while drawing the knife along the channel;

discarding the marginal strip thereby provided;

turning the guide about 180.degree. and placing the vertical wall portion adjacent the cut edge of the first carpet portion;

placing the margin of the second portion of carpet over the channel, inserting the blade therein, drawing it therealong and discarding the marginal strip thereby produced;

removing the guide and allowing or causing the two cut edges to fall together;

adhering the cut edges to the floor or otherwise joining them together.

In this way, the lower base may be retained adjacent a cut edge of the first portion of carpet while the upper base portion is moved along underneath the second portion of carpet to thereby ensure that the cut edges always remain parallel to one another.

In order that the invention may be better understood it will now be described with reference to the accompanying diagrammatic drawings in which:

FIG. 1 is a perspective exploded view of a cutting guide of the invention;

FIG. 2 is an end view of the guide of FIG. 1 at a stage of use; and

FIG. 3 is the same as FIG. 2 at a further stage of use.

In FIG. 1 a cutting guide comprises an elongate lower base portion 1 having a substantially flat underside 2. One longer side of the lower base 1 defines a ramp portion 3 which is inclined upwardly from one side edge 2A of the base 1. The opposing side of the base defines a vertical wall 4. The upper surface 5 of the base 1 is generally parallel to the underside 2, but is formed with an integral rail 6 which extends along the length of the base 1 and is generally of a broad "T"-shape in cross-section. The end face 7 of the lower base 1 may include interlocking lugs (not shown), whereby a plurality of such bases 1 may be placed in end-to-end relation, so as to extend the length of the track 6.

An elongate upper guide portion 8 overlies the lower base portion 1 and has a substantially flat underside 9 including a slot 10 which is of a generally "T"-shaped section and which is complementary to the rail 6 on the lower base 1. The upper portion 8 includes a side ramp portion 11 on the upper surface which is inclined upwardly from one side. A channel 12 extends along the base 8, at the top of the ramp 11 parallel to the edge 2A. The channel 12 includes an inner side wall 13 which is inclined at an oblique angle to the adjacent ramp portion 11. The upper and lower base portions 1, 8 are dimensioned so that when the rail 6 is received in the slot 10 to form a longitudinal slideway, the vertical wall portion 4 lies "vertically" (see the comments herein after) below the mouth of the channel 12 with which it is parallel. The upper surface 14 of the upper base 8 beyond the channel 12 is horizontal and ends in a vertical side wall 15. The side wall 15 defines an inwardly extending "T"-shaped slot 16 to receive a complimentary "T"-shaped extension 17 of a stop 18 or upstanding side wall which extends above the level of the upper surface 14. Each base portion 1, 8 may be formed as an extrusion from aluminium or like alloy, or may be formed from plastics material.

In use of the guide, the upper portion 8 is slid into position above the lower base 1 and the stop 18 is fixed in the slot 16. The guide is then placed underneath the margin of the first piece of carpet 20 to be joined, with the free edge in contact with the stop 18. The blade of a knife 21 is inserted in the channel 12 and urged towards the oblique side wall 13. The knife 21 is drawn along the channel 12 to cut off the margin of the carpet 20. In the case where a plurality of lower bases 1 are joined end to end, the upper base 8 may be periodically moved along the slideway formed between the 6 and slot 10 and relative to the lower base 1, as the cut is made. The margin is then discarded. The guide is then turned about through 180.degree., to the condition shown in FIG. 3, and the vertical wall 4 placed against the cut edge 22 of the first portion of the carpet 20. The second portion 23 of the carpet to be joined is then lain over the channel 11 with the edge thereof in contact with the stop 18. The blade of the knife is then inserted in the channel and drawn therealong as before, to produce a cut edge 24. The margin thereby produced is discarded. Because the vertical wall 4 is "vertically" (see below) beneath the mouth of the channel 12, once the guide has been removed, the two cut edges 22, 24 fall together in abutting edge to edge contact. It will be appreciated from the foregoing that for the two cut edges 22 and 24 to fall together in abutting edge to edge contact, the length of the carpet 23 extending over the ramped surfaces 3 and 11 to its cut edge 24 should substantially correspond to the width of the underside 2 of the base portion 1. Consequently to allow for the ramps 3 and 11, the mouth of the channel 12 will be offset from vertical alignment with the wall 4 and located slightly closer (in a horizontal plane) to the longitudinal edge 2A formed between the ramp 3 and underside surface 2 then the horizontal spacing between that longitudinal edge 2A and the wall 4. In practice this difference in horizontal spacing is likely to be extremely small so that the mouth of the channel 12 may be considered as being substantially in vertical alignment with the wall 4; for example in a practical embodiment the overall height of the base 1 and guide portion 8 (fitted thereto through the slideway) may be 13 millimeters with the ramps 3 and 11 subtending an angle of approximately 20.degree. with the underside face 2 and for the cut carpet portions to fall together with their edges 22 and 24 in abutment, the mouth of the channel 12 may be offset as aforementioned by approximately 1.5 millimeters out of absolute vertical alignment with the wall 4. Consequently the spacing from the edge 2A over the profile of the ramped surfaces 3 and 11 to the channel 12 is substantially the same as the spacing from the edge 2A over the flat underside surface 2 to the vertical wall 4. The two cut edges 22, 24 may be adhered to the floor or otherwise attached together.

The invention is not limited to the embodiment shown. For example, the cutting device may be integrally formed with the base.