WO1993012917A1

WO1993012917A1 - Pipe cutter

Info

Publication number: WO1993012917A1
Application number: PCT/AU1992/000685
Authority: WO
Inventors: Wayne Noel Doyle
Original assignee: Wayne Noel Doyle
Priority date: 1991-12-23
Filing date: 1992-12-23
Publication date: 1993-07-08
Also published as: AU3251893A

Abstract

A pipe cutting tool has a cutting wire (11, 20) passed around a pipe (10, 16) and via rollers (12, 13, 28, 29) to a remote location whereat ring pulls (14, 15, 21, 22) enable the cutting wire (11, 20) to be pulled to and fro around the pipe (10, 16). The rollers (28, 29) can be mounted in a support means (17) clamped to pipe (10) by a clamping means (18) to hold the tool in place at the level to be cut.

Description

Title: "PIPE CUTTER"

FIELD OF THE INVENTION

THIS INVENTION relates to an apparatus whereby a pipe may be cut at a point which is not readily approached with conventional tools.

BACKGROUND OF THE INVENTION

Plumbers utilising plastic and the like pipes often find that they have a need to cut a pipe at a location which is not readily accessible to permit pipe cutting using any of the usual tools. Whilst plastic pipe might be easily cut, if the required cut is at a point say below floor level, on a pipe passed through a slab, then a considerable amount of slab material may have to be removed to permit a hacksaw or like cutting tool access to the pipe.

OBJECT OF THE INVENTION

It is an object of the invention to provide a pipe cutting apparatus which is able to cut transversely through a pipe from a remote location. OUTLINE OF THE. INVENTION

The invention achieves its objects in provision of a pipe cutting apparatus which comprises: an elongate flexible cutting means passed, in use, about the circumference of a pipe; characterised in that the elongate flexible cutting means being passed around roller means to extend away from the pipe to a location remote from the pipe; the roller means being secured relative to the pipe by a clamping means thereabout; said clamping means locating said roller means relative to the pipe; and the elongate flexible cutting means being passed to engagement means whereby the elongate flexible cutting means may be moved to and fro around the circumference of the pipe to cut into the surface of the p pe.

In a preferred form, the elongate flexible cutting means is a wire like cutting element provided with an abrasive as the cutting means. The roller means can be effective to turn the direction of the cutting wire through 90° to extend parallel to the pipe axis. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an isometric schematic diagram illustrating the basic elements of a cutting apparatus in accordance with the present invention;

FIG. 2 is a transverse section through the cutting apparatus of FIG. 1;

FIG. 3 is a schematic illustration showing how a cutting apparatus in accordance with the invention might be made to operate; and

FIGS. 4 and 5 are more detailed views of elements of the apparatus of FIG. 3.

The illustrations are schematics only. They are not intended to suggest any particular scale of apparatus or any set of relative proportions of parts of the apparatus.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In FIG. 1 a pipe 10 has a cutting wire 11 thereabout. The cutting wire is a length of filamentary material with a cutting or abrasive material bonded thereto. On movement of the cutting wire over the surface of the pipe, the abrasive is selected such that a cut can be effected. The nature of the cutting cord, wire, etc. might be varied. Its basic requirement is a cutting action suited to the material of the pipe 10.

In practice, the cutting action to be effected by the cutting apparatus of this invention is to be effected from a remote location, usually from a point which is axially displaced along the length of the pipe. In order to effect this requirement, the encircling length of cutting wire needs to be passed around rollers 12 and 13 to extend the cutting wire axially to two means 14 and 15 such a pull rings by which the cutting wire can be grasped and pulled. It will be clear that alternate pulls on the two means 14 and 15 pulls the encircling length of cutting wire 11 to and fro around the perimeter of the pipe. This action will effect a cut in the pipe. FIG. 2 further illustrates the basic geometry. A crank mechanism might be provided by which to actio -the pull means 14 and 15.

In FIG. 3 a pipe 16 which is to be cut has a cutting apparatus support means 17 mounted thereto by a clamp 18 encircling the pipe. The clamp 18 is provided with a locking means indicated, generally at 38 whereby the clamp may be opened for application to the pipe and be slid down to where a cut is to be made. At this point the clamp is actioned to lock it onto the pipe and hold the cutting apparatus in place. To effect this the clamp might be a locking band, split at a point whereat a lever actioned, over centre locking means might be actioned to pull the locking band tight to the pipe and the lock it in place until released. To stabilise the top end of the cutting apparatus support means 17, another clamp 19 might be fitted at the top when the support means is extended parallel to the pipe. The cutting wire 20 extends down and around the pipe 16 in the same way as in FIGS. 1 and 2. Means 21 and 22 are provided by which to engage and action the cutting wire 20. The two lengths of cutting wire 23 and 24 pass around roller means 28 and 29 to pass oppositely at 25 and 26 around the pipe inside groove 27 in clamp 18. By this means the surrounds to the pipe 16, slab 31 in the drawings, need be cut back only sufficiently to enable the cutting apparatus to be slid into place into a hole 30 about the pipe which is much smaller than what would be required if the cut was to be made with a hacksaw.

FIG. 4 is a transverse vertical section through clamp 18 which encircles pipe 16 with cutting wire 20 in groove 27. FIG. 5 shows a detailed view of a means whereby the direction of the cutting wire 35 can be changed from axial to circumferential. This device can be used as the roller means 12, 13, 28 and 29 of FIGS. 1 to 3. In this device a supporting annulus 32 is rotationally freely supported in bearing blocks 33 and 34. The annulus 32 supports two rollers 36 and 37. The two rollers 36 and 37 are closely spaced and are narrowed at a waist to create a space for passage of the cutting wire 35 therebetween. In use, as a cut proceeds, and the wire direction changes, the roller support can turn to optimally support the wire.

Claims

1. A pipe cutting apparatus which comprises: an elongate flexible cutting means passed, in use, about the circumference of a pipe; characterised in that the elongate flexible cutting means being passed around roller means to extend away from the pipe to a location remote from the pipe; the roller means being secured relative to the pipe by a clamping means thereabout; said clamping means locating said roller means relative to the pipe; and the elongate flexible cutting means being passed to engagement means whereby the elongate flexible cutting means may be moved to and fro around the circumference of the pipe to cut into the surface of the pipe.

2. A pipe cutting apparatus as in Claim 1 wherein: the flexible cutting means is a wire with an abrasive adhered thereto.

3. A pipe cutting apparatus as claimed in Claim 1 wherein: the flexible cutting means is provided at each end with a ring pull.

4. A pipe cutting apparatus as claimed in Claim 1 wherein: the roller means is a pair of waisted wires which capture the flexible cutting means therebetween.

5. A pipe cutting apparatus as claimed in Claim 4 wherein: the pair of waisted rollers are mounted in a freely rotatable annulus supported in bearing blocks.

6. A pipe cutting apparatus as claimed in Claim.1 wherein: said clamping means is a split band with locking means thereacross by which the split band ends are brought together to clamp a pipe within the band by action of the locking means>

7. A pipe cutting apparatus as claimed in Claim 6 wherein: the split band has a groove therein on the inside for passage of the elongate flexible cutting means.