PIPE PREPARING TOOL IIIThis invention relates to pipe preparing tools, and more particularly to a novel pipe preparing tool suitable for cutting, scoring or penetrating a surface of a plastic pipe.
Composite plastics pipes comprising an inner core and an outer protective layer are known. The outer protective layer may, for example, provide environmental protection, or protection against mechanical damage when the pipe is laid in a trench. In joining sections of such a pipe, it has been proposed to remove the outer protective layer in the regions surrounding the pipe ends to be joined in order to permit the installation of a pipe coupler, such as, for example, an electrofusion pipe coupler. Examples of such pipes with outer protective layers are described in WO-A-9300212, WO-A-9215818, European Patent Application No 0474583 and in WO-A9622485 the entire disclosures of which are incorporated herein by reference for all purposes.
In practice it has proved to be extremely difficult to remove the outer protective layer cleanly from the pipe inner core without damaging the inner core when using conventional tools such as knives, scrapers etc.
In GB1487033 there is described a tube cutting and chamfering tool comprising an adjustable C-shaped frame, a pair of spaced cutting wheels arranged in a common plane, supporting rollers for the tube, and a chamfering cutter adjustably located between the two cutting wheels.
This tool is quite complex in design and is not readily adapted to remove the outer protective layer of a composite pipe.
GB1458366 describes a tool for cutting a cable sheath which comprises a loop-like frame, including at least two hingedly connected parts, means for releasably holding the frame parts in closed loop form, a handle connected to the frame, and a cutter assembly mounted for adjustment both inwardly and outwardly of the loop and angularly about the axis of its inward and outward movement. The cable sheath is supported by rollers mounted on the frame and, in some embodiments, also on the cutter assembly. This tool is complex both in design and operation.
In GB2296886 there is described and claimed a pipe preparing tool which comprises:a frame having an opening adapted to receive a pipe or a portion thereof; a first tapered roller means mounted transversely on the frame;a second tapered roller means mounted transversely on the frame and spaced apart from the first tapered roller means;the arrangement being such that the first and second tapered roller means have opposed directions of taper;a cutting, scoring or penetrating means mounted on the frame and spaced apart from the first and second roller means; andclamping means adapted to apply a clamping force to the pipe such that the first and second tapered roller means and the cutting, scoring or penetrating means are brought into contact with the pipe and the cutting, scoring or penetrating means penetrates a surface layer of the pipe;the arrangement being such that the pipe and the tool can be rotated relatively to one another about the axis of the pipe whereby the cutting, scoring or penetrating means produces a helical groove in at least a surface layer of the pipe.
This tool works well in practice, and can be used to strip off the outer layer of a composite pipe, but again some further simplification of the design would be desirable. In particular, it would be desirable to provide a cheaper tool and one wherein the number of moving parts, such as rollers, can be reduced or eliminated.
The present invention provides a pipe preparing tool of relatively simple construction capable of cutting or scoring a helical groove in a pipe outer surface. In appropriate embodiments, the outer protective layer only can be penetrated, so that it can readily be peeled cleanly away from the inner core without any substantial damage to the inner core.
In a first aspect, the present invention provides a pipe preparing tool which comprises:a body portion,a handle or grip attached to or integral with the body portion,cutting, scoring, or penetrating means mounted on or in the body portion, or integral therewith, a bearing means adapted, in use, to bear against the surface of the pipe, anddepth control means whereby the depth to which the cutting, scoring, or penetrating means penetrates the pipe can be controlled.
Preferably, the bearing means is mounted on or integral with the body portion. Preferably, the depth control means is mounted on the body portion, and is variable in position so that the depth to which the cutting, scoring, or penetrating means penetrates the pipe can be varied.
In a preferred embodiment of a tool according to the invention the body portion, bearing means and handle or grip are all comprised in an integral moulded structure.
Preferably the cutting, scoring, or penetrating means is mounted in the body portion and protrudes therefrom. The cutting, scoring, or penetrating means is preferably fixedly mounted in the body portion, although the possibility that the cutting, scoring, or penetrating means can be moved between fixed positions relative to the body portion is not excluded.
Preferably, the depth control means comprises a pivotally mounted second bearing means which can be moved between two or more positions by means of a hand-operated lever. Preferably the depth control means is pivotally mounted on or in the body portion.
In a preferred embodiment of a tool according to the invention, the bearing means and depth control means are arranged on either side of the cutting, scoring, or penetrating means, and, preferably, in the plane thereof.
Preferably, the bearing means is adjacent the leading edge of the cutting, scoring, or penetrating means, and the second bearing means of the depth control means is positioned adjacent to the trailing edge of the cutting, scoring, or penetrating means.
Any suitable cutting, scoring, or penetrating means can be used in the pipe preparing tool of the invention.
As examples, there may be mentioned, a tool bit comprising a fixed blade with a straight bottom, a tool bit comprising a fixed blade with a V-shaped bottom, or a tool bit having a knife edge and a lifting action.
Other types of cutting, scoring or penetrating means can also be used, for example, knife blades, cutting wheels, points and similar devices. A combination of two or more cutting, scoring, or penetrating means may be used. For example, the tool may be provided with a sharp point for scoring or penetrating an outer layer of the pipe, together with a knife blade for cutting or peeling an outer layer of the pipe. Particularly where a knife blade is used, guard means, may be used to protect the operator, if desired.
Once the tool has been placed against the pipe, the cutting, scoring or penetrating action is obtained by relative rotation of the tool and the pipe. The tool handle or grip can, for example, allow the tool to be rotated about the pipe and also to be moved along the length of the pipe.
The depth control means can allow the cutting, scoring or penetrating means to penetrate the pipe surface layer to a predetermined depth, for example, to the depth of the outer layer of a composite pipe.
An embodiment of a preparing tool of the invention will now be described, by way of example only, with reference to the accompanying Drawings in which:Figure 1 shows a side elevational view of a preparing tool according to the invention partly in section, with the depth control means set for a deep cut; andFigure 2 shows a side elevational view of the tool of figure 1 partly in section, with the depth control means set for a shallow cut.
Referring firstly to figure 1, there is shown a hand tool illustrated generally at 1 in use to score a cut in the outer surface 2 of a pipe 3.
The tool has a body portion 4 which has a handle 5 integral therewith. Also integral with the body portion 4 is a generally cylindrical bearing surface 6.
A cutting blade 7 is mounted within the body portion 4 with a blade tip 8 protruding therefrom. Pivotally mounted behind the blade tip 8 is a second cylindrical bearing surface 9 which has a spring steel cover 10. The second bearing surface 9 is carried on an arm 11 which is attached at a pivot point 12 to the body portion 4. The end of the arm 11 remote from the second bearing surface 9 is attached to a lever 13 which extends through a slot 14 in the body portion 4, so that the arm 11 can be moved by the lever 13 between the extremities 15 and 16 of the slot 14.
In figure 1, the lever 13 is shown adjacent the end 16 of the slot 14. In this position the bearing surface 9 is pivoted away from the cutting tip 8, thereby allowing the tip 8 to cut more deeply into the surface 2 of the pipe 3 as shown. In figure 2 the lever 13 has been moved in the slot 14 toward the end 15 thereof, such that the bearing surface 9 has been shifted by the pivotal movement of the arm 11 into a position adjacent to the cutting tip 8, thereby reducing the depth of cut as shown.
In use the tool is moved around or along the pipe to make the desired cut in the outer layer of the pipe.
Removal of the outer layer may be effected by scoring the outer layer with a helical rotary action of the tool in order that a single complete strip can be unwound from the pipe, for example to allow electrofusion couplings to be fitted, or by a zig zag action, for example, to cut a window for the fusion of a tapping tee. A portion of the outer layer can be removed with the aid of a lifting device which can prise the outer layer from the base pipe so that sufficient of the outer layer is lifted to allow the operative to obtain a grip and continue removal by hand.
The invention provides a simple and economical tool for making spiral and ring cuts in the outer surface of a pipe, and which is particularly suitable for assisting in the peeling back and removal of the outer layer of a composite pipe, for example, when the pipe is to be joined using an electrofusion coupler. Removal of the outer surface layer can be achieved to expose a clean pipe surface for electrofusion without damaging the underlying body of the pipe.
Whilst the invention has been described with references to a tool for cutting a groove in an outer protective layer of a pipe, it will be apparent that the tool could also be used to cut a groove throughout the entire thickness of the pipe to cut the pipe to length or to produce a helical plastics strip, should such be desired.
The reader's attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
All the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps or any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.