WO1999038635A1

WO1999038635A1 - Pipe preparing tool

Info

Publication number: WO1999038635A1
Application number: PCT/GB1999/000104
Authority: WO
Inventors: Anthony Robert Shelton
Original assignee: Uponor Innovation Ab
Priority date: 1998-01-28
Filing date: 1999-01-27
Publication date: 1999-08-05
Also published as: GB0018460D0; AU2173299A; GB2333733A; GB2348846A; GB9801845D0

Abstract

A wraparound pipe preparing tool which comprises: a flexible strap of a length sufficient to pass around a pipe, releasable fastening means for securing the strap at selectable points along the length of the strap, preferably, the ends of the strap, and a cutter assembly mounted on the strap and comprising a cutting, scoring or penetrating means, the cutter assembly being adapted in use to contact the outer surface of the pipe and to cut, score or penetrate an outer layer of the pipe by relative movement of the pipe preparing tool and the pipe.

Description

PIPE PREPARING TOOL

This 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 O-A- 9622485, 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 movemen . 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.

US Patent No. 3943626 describes a pipe cutter adapted to be mounted on a chain pipe wrench. The pipe cutter comprises a cutter bit which projects adjustable beyond a rigid body member mounted on guide wheels. GB2207377 describes a plastic pipe cutter which comprises a set of pipe grips and a cutting tool ring. The cutting tool ring comprises two half round steel bands which are hinged and have a fastening clamp. The cutting tool is housed in a rigid slotted boss. GB2145647 describes a tool for removing a surplus bead of material from a pipe. The tool comprises a blade carried in a rigid blade holder formed in two half body portions carried on releasable clamping means comprising a pair of semicircular steel straps.

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; and clamping 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 wraparound pipe preparing tool which comprises:

a flexible strap, of a length sufficient to pass around the pipe,

releasable fastening means for connecting the ends of the strap, a flexible base plate connected to the strap, and

a cutter assembly mounted on the base plate and comprising a cutting, scoring or penetrating means,

the cutter assembly being adapted in use to contact the outer surface of the pipe and to cut, score or penetrate an outer layer of the pipe by relative movement of the pipe preparing tool and the pipe.

A second aspect provides a wraparound pipe preparing tool which comprises :

a flexible strap of a length sufficient to pass around a pipe,

releasable fastening means for securing the strap at selectable points along the length of the strap, said points being preferably at the ends of the strap, a flexible base plate connected to the strap, and

The pipe preparing tool of the present invention is wraparound, that is to say that it extends, in use, completely around the pipe. In a preferred embodiment of the invention the flexible strap passes around the pipe and is provided, at least at one end, with releasable fastening means for connecting the ends of the strap together. The fastening means preferable is adjustable, such that the flexible strap can be fastened at several positions along its length in order to accommodate different diameters of pipe. Preferably the strap has a free end which can be passed through or around the releasable fastening means and locked at any position along its length in order to allow for complete adjustability.

The flexible strap can be formed, for example, from any suitable fabric material, reinforced fabric material, or thermoplastic material, or any combination thereof. The length of the flexible strap will, of course, depend upon the diameter of the pipe or the range of diameters of pipe for which the tool is to be used, and the width of the strap is preferably from 40mm to 90mm, for example, about between 50mm and 60mm. The strap may have any suitable thickness consistent with the necessary flexibility, and, for example, a thickness of from 1mm to 3 mm, such as, about 2.5mm, has been found to be very suitable. It will be appreciated that the thickness and/or width of the strap can be varied according to the characteristics of the material or materials used to realise the strap or according to the construction of the strap.

The releasable fastening means can, for example, be of a belt buckle type, or it can have a friction lock or any other suitable fastening device.

The cutter assembly is mounted on a base plate which can itself form part of the length of the flexible strap. The base plate is also flexible, and can, for example, comprise a sheet of plastics material. Any suitable plastics material may be used, although it is often an advantage if the material is transparent. A suitable plastics material is, for example, perspex, and the plastics material can have a thickness of from 1mm to 3mm mm, preferably, 1.25mm or 1.5mm. In a preferred embodiment according to the invention, the base plate is joined to an end of the flexible strap, and also carries the releasable fastening means in addition to the cutter assembly. In certain embodiments the base plate may be readily removable from the flexible strap in order that it can be used with straps of different length.

The cutter assembly preferably comprises the cutting, scoring or penetrating means, and means for locating the cutting, scoring or penetrating means on the base plate.

Any suitable cutting, scoring, or penetrating means can be used in the wrap-around 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 similarly devices . In a preferred embodiment of a wrap-around tool according to the invention, a combination of two or more cutting, scoring, or penetrating means is 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. Individual cutting, scoring or penetrating means are preferably provided in spaced apart locations on the base plate, although this is by no means essential. Particularly where a knife blade is used, guard means, for example, a transparent perspex cover, may be used to protect the operator.

Once the wrap-around tool has been assembled on the pipe, the cutting, scoring or penetrating action is obtained by relative rotation of the tool and the pipe. The tool can, for example, be provided with a knob or handle which allows the tool to be rotated about the pipe and also to be moved along the length of the pipe.

The pipe preparing tool of the invention is preferably provided with a depth control means such that the cutting, scoring or penetrating means penetrates the pipe surface layer to a predetermined depth, for example, to the depth of the outer layer of a composite pipe. The cutting, scoring or penetrating means can, for example, be mounted on a hollow screw-threaded boss member, and be provided with a co-operating screw thread, such that the depth of cut can be varied by rotation of the cutting, scoring or penetrating means.

Embodiments of a wrap-around pipe 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 sectional side elevational view of a wrap-around pipe preparing tool according to the invention;

Figure 2 shows a plan view of the tool of figure 1 taken from the top;

Figure 3 shows a plan view of the tool of figure 1 taken from below;

Figure 4 shows an end elevational view of the tool of figure 1; and

Figure 5 shows a perspective view of a pipe prepared using a tool according to the invention, illustrating the peeling off of an outer protective layer.

Referring firstly to figure 1 the tool, illustrated generally at 1, comprises a flexible nylon strap 2, of width 50mm and thickness 1mm, which is attached to a base plate 3 formed from a flexible transparent perspex sheet of thickness 1.5mm. The strap 2 and base plate 3 overlap in the region 4 wherein are located a cutter assembly 5 and a knife assembly 6. The cutter assembly 5 comprises a cutter 7, comprising a socket grub screw provided with a sharpened point, which is positioned in a threaded hole 8 in a flat aluminium bar 9. The bar is clamped to the base plate 3 and flexible strap 2 by means of screws 10 which pass through the base plate and flexible strap and join the bar 9 to a lower bar 11. The socket grub screw 7 can be locked in position by means of a lock nut 12.

Referring now to figures 2 and 3, the knife assembly 6 comprises a stainless steel cutting blade 13 which is clamped to the base plate 3 and flexible strap 2 by means of screws 14 which pass through the base plate and the flexible strap from a second lower aluminium bar 15. The screws also carry a protective perspex cover 16 which is mounted above the knife blade 13.

The fastening means, illustrated generally at 20, comprises an upper aluminium locking bar 21 and a lower aluminium bar 22 joined by means of screws 23 which pass through the base plate 3. Steel washers 24 act as spacers between the locking bars 21 and 22 and enable a locking device 25, comprising a profiled aluminium bar, to be inserted between them, as shown in figure 1. In use, by slackening off the nuts on the screws 23 the flexible strap 2 can be pulled through the fastening means to the appropriate position and then locked by the locking device 25 whilst the screws 23 are tightened.

The tool as illustrated does not have a handle or knob, but it will readily be understood that this could easily be provided either on the base plate or the flexible strap to enable the tool to be 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.

An example of a composite pipe prepared in accordance with the invention is shown in Figure 6. The composite pipe 60 has an outer layer 61 in which a spiral groove 62 has been cut using a tool in accordance with the invention. A portion of the outer layer 61 has been peeled back as shown at 63.

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.

Claims

CLAIMS 1. A wraparound pipe preparing tool which comprises :

a flexible strap of a length sufficient to pass around a pipe,

releasable fastening means for securing the strap at selectable points along the length of the strap, said points being preferably at ends of the strap, a flexible base plate connected to the strap, and

A tool according to claim, in which the flexible strap is provided, at least at one end, with releasable fastening means for connecting the ends of the strap together.

A tool according to claim 2, in which the fastening means is adjustable, such that the flexible strap can be fastened a several positions along its length in order to accommodate different diameters of pipe.

4. A tool according to claim 2 or 3 , in which the strap has a free end which can be passed through or around the releasable fastening means and locked at any position along its length.

5. A tool according to any of the preceding claims, in which the releasable fastening means is provided with a friction lock.

6. A tool according to any of the preceding claims, in which the base plate which itself forms part of the length of the flexible strap.

7. A tool according to claim 6, in which the base plate comprises a sheet of plastics material .

8. A tool according to claim 6 or 7 , in which the base plate is transparent.

9. A tool according to any of claims 6 to 8, in which the base plate is joined to an end of the flexible strap, and also carries the releasable fastening means in addition to the cutter assembly.

10. A tool according to any of claims 6 to 9, in which the cutter assembly comprises the cutting, scoring or penetrating means, and means for locating the cutting, scoring or penetrating means on the base plate .

11. A tool according to any of the preceding claims, in which the cutting, scoring or penetrating means comprises 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.

12. A tool according to any of the preceding claims, which comprises a combination of two or more cutting, scoring or penetrating means.

13. A tool according to any of the preceding claims, which also comprises guard means for the cutting, scoring or penetrating means.

14. A tool according to any of the preceding claims, which is provided with a knob or handle whereby the tool can be rotated about the pipe and also moved along the length of the pipe.

15. A tool according to any of the preceding claims, which is provided with a depth control means such that the cutting, scoring or penetrating means penetrates the pipe surface layer to a predetermined depth.

16. A tool according to claim 15, wherein the cutting, scoring or penetrating means is mounted on a hollow screw-threaded boss member, and is provided with a co-operating screw thread, such that the depth of cut can be varied by rotation of the cutting, scoring or penetrating means.

17. A tool according to any of the preceding claims substantially as hereinbefore described with reference to and as illustrated in the accompanying Drawings .

18. A wraparound pipe preparing tool substantially as hereinbefore described.