GB2426220A

GB2426220A - Pipe cutter

Info

Publication number: GB2426220A
Application number: GB0510120A
Authority: GB
Inventors: Steven Taylor
Original assignee: HILCREST DESIGN Ltd
Current assignee: HILCREST DESIGN Ltd
Priority date: 2005-05-18
Filing date: 2005-05-18
Publication date: 2006-11-22
Anticipated expiration: 2025-05-18
Also published as: GB0510120D0; GB2426220B; FR2885832A1; FR2885832B1

Abstract

The present invention provides a pipe cutter suitable for manual use to cut an opening into a wall of a pipe and which is adapted to be used in combination with a saddle that mounts over the pipe. The cutter has a cutting head 11 and a moulded plastics body 10 formed with a screw thread that co-operatively engages with a corresponding screw thread of the saddle, whereby the cutting head of the cutter may be advanced to cut into the pipe. The cutting head is formed from a sheet of metal or metal alloy or other suitable material and is cut and bent or pressed out from the sheet to an arcuate cutting shape to cut a circular hole and assembled with the cutter body. The cutting head may be push/ snap- fitted to the body and may be demounted to facilitate recycling. A handle bar/rod may be inserted through an aperture 20, to enable the cutter to be turned.

Description

I

Improved Pipe Cutter

Field of the Invention

The present invention concerns improvements in and relating to pipe cutters that are particularly, but not necessarily exclusively, suitable for cutting laterally into plastics pipework to mount branch pipes, valves or other fittings.

Background to the Invention

In order to form an opening into the circular cylindrical wall of a first pipe to couple a second pipe extending transversely to the first pipe, one method is to mount a saddle onto the first pipe to hold a cutting tool at the required angle (generally orthogonal to the axis of the pipe - i.e. extending in a radial direction).

For cutting such openings in plastics pipework using a saddle one popular tool for the purpose comprises a cutter I that mounts into a two part saddle assembly 2a, 2b which embraces the plastics pipe 6 as shown in Figures Ia, I b and 2 hereinafter.

The cutter I comprises a rigid metal, e.g. steel, cylinder having an external thread 3 around its circumference and with an integrally formed or assembled cutting profile 4 at its cutting end formed by turning and milling of the end of the cylinder but the cylinder may be insert-moulded with a plastics body. The threaded portion 3 of the cutter 1 threadedly engages with a corresponding internal thread 5 of a receiving socket 6 in the saddle 2a, 2b whereby rotation of the pipe cutter I about its longitudinal axis can be used to threadedly advance the pipe cutter I within the saddle 2a, 2b in a controlled manner to cut the required opening into the plastics pipe 6. This type of pipe cutter assembly is particularly suited to manual operation and has at its upper end (i.e. end remote from the pipe being cut) an integral crossbar formation 7 to serve as a handle for manual rotation of the cutter (see Figure IB) Once the cutter I has cut the required hole into the side of the first pipe 6 it is removed from the screw threaded part of the saddle and the second pipe 7 or fitting is mounted therein and secured with its associated screw threaded lock nut collar 8.

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* a a a a * S a * S. S I *.

* a a.. * I S * * I I I S a. * * 2 *** * a This existing system is a fairly cost effective and simple system for joining into existing plastics pipework to fit branch pipes or valves etc, and operates well for most domestic plastics pipework especially, for example, with pipes with outside diameters of the order of 30 to 50mm. Nevertheless, there is scope for improving upon this existing system, reducing the cost of its manufacture and improving its corn petitiveness with existing alternative systems.

A significant component of the cost of the system is the cost of fabrication of the turned and milled metal cutter itself, which in its present form cannot readily be reduced. Another component of the cost is the handling of the device after use.

Summary of the Invention

According to a first aspect of the present invention there is provided a pipe cutter suitable for manual use to cut an opening into a wall of a pipe and which is adapted to be used in combination with a saddle that mounts over the pipe, the cutter having a cutting head and having a moulded plastics body formed with a screw thread that co-operatively engages with a corresponding screw thread of the saddle whereby the cutting head of the cutter may be advanced to cut into the pipe, wherein the cutting head is formed from a sheet of metal or metal alloy or other suitable material, being cut out or pressed out from the sheet and bent to an arcuate cutting shape to cut a circular hole and assembled with the cutter body.

Particularly preferably the body of the cutter is moulded of plastics and suitably the cutting head is formed of metal or metal alloy. Preferably the body of the cutter is moulded to have a receiving formation to receive the cutting head and that suitably has a recess into which a part of the cutting head engages.

The cutting head suitably is formed from a sheet of metal or metal alloy and is cut or pressed out from the sheet to the required shape, suitably being folded into a 3- dimensional form having at least two cutting end portions each suitably with a plurality of cutting teeth and wherein the cutting end portions are joined by a bridging portion suitably transverse and preferably perpendicular to the cutting end portions.

Preferably the body of the cutter is formed as a tube and preferably the cutter head in its arcuate cutting end defines a recess or bore of the cutting end wherein a cut * *.* I.e S II * I I * I I S I I S **I S I ** * I III S I S S * S S I S I I * 3 1S* S 1 out of pipewall of a pipe that is cut out by the cutter in use may be held entrapped in the cutter head and thus withdrawn from the pipe on retraction of the cutter.

Preferably the cutter is further provided with a socket extending there across through which a separate rod or bar may be inserted to serve as a handle for turning of the cutter. Where such a socket is provided it may be formed of two parallel openings in the tubular side wall of a tubular cutter body. Suitably the socket, e.g. opposed apertures, is augmented with lateral projections from the cutter body, suitably in the form of extension sleeves, providing additional support between the handle rod or bar and the cutter body.

In further enhancement of the cutter, it suitably has facets around its outer wall part- way therealong or at one end thereof and which allow for use of a spanner, pliers, wrench or similar means for gripping and turning the cutter if required. In one preferred arrangement this comprises a nut-shaped moulding or formation at the end of the cutter remote from the cutting head end of the cutter.

In a further improvement the cutter body preferably at its end remote from the cutting head end is provided with a socket to receive the cutter head to store the cutter head prior to and/ or after use.

Where the cutter is provided with a socket to receive a separate rod or bar as a handle, the rod or bar may be provided together with the cutter as a modular assembly kit and suitably is moulded of plastics but may be of steel or other suitable material.

Brief DescriDtion of the DrawinQs A preferred embodiment of the present invention will now be more particularly described by way of example with reference to the following drawings, wherein: Figure 1A is a perspective view of the prior art manual pipe cutting system showing the saddle of that system being mounted to a pipe to be cut, Figure 1 B shows the same assembled to the pipe and with the cutter being advanced into screw threaded engagement with the mating screw thread of the saddle in order to cut the required * I,, *.S * t,* * I I I I I *

I I S SI I I IS

I I Ill S I S S * S S * * I I * I 4 *5, I I S hole into the pipe to subsequently receive a joining pipe; and Figure 2 shows the cutter removed and the second pipe mounted in place in the saddle; Figure 3 is a perspective view of a first preferred embodiment of the cutter of the present invention showing the separate cutting head both in its working position at the cutting end of the cutter body and also in its stowed position in the opposing end of the cutter body; Figure 4 is a perspective view similar to Figure 3 but solely of the cutter body and from which the formation of the cutter end of the cutter body to receive the separate cutter head is clearly visible; Figure 5 is a close-up view of the cutting end of the cutter body and of the cutter head being approached to the cutting end; Figure 6 is a perspective view similar to Figure 3 but of a modified form of the cutter body having a nut-shaped formation at one end to assist in use of a tool such as a wrench, spanner or other suitable tool for operation of the cutter and further showing supportive extension sleeves/shoulders around the sockets to receive a separate rod or bar for rotation of the cutter; Figures 7 to 11 are, respectively, a perspective view, front elevation view, side elevation view and bottom and top plan views of the cutter body of the second preferred embodiment; and Figures 12 to 15 are, respectively, first and second perspective views and side elevation and bottom plan views of the cutter head of the cutter.

DescriDtion of the Preferred Embodiments Referring now to Figure 3, this shows a cutter embodying the present invention and which comprises a moulded plastics circular cylindrical tube 10 defining the main body of the cutter and which like the cutter I of the prior art has an external thread 3 around its circumference extending towards the lower, cutting, end. Unlike the cutter I of the prior art, the preferred cutter of the present invention is of modular construction wherein each of the cutting head II of the cutter and the cutting body * ,,, I,. S * I I I * a p * If a p II * p Ips * a a a * * I * I I p * * II* P a a a of the cutter are formed as separate components and where the cutting head 11 is clip-mounted to the cutting end of the pre-formed cutter body 10 at a special receiving formation on the cutting end of the body 10. In this preferred embodiment it is not assembled to the body during moulding formation of the body. However, in an alternative embodiment that is not illustrated, it may be insert moulded, being assembled in the cutter body during formation of the cutter body.

Referring to Figures 12 to 15, whether to be assembled to the cutter body 10 by insert-moulding or by clip-mounting, the cutting head Ills formed as a pressed out or cut out metal component formed from a sheet of metal such as steel. It is shown as having two cutting end portions 11 a, 11 b each with a plurality of cutting teeth I serrations 12 and linked by a bridging length 13. In forming this head 11 from the sheet of steel or other metal or metal alloy (or even a special high strength/hardness plastics or other material) the end portions 11 a and 11 b are effectively bent upwardly to stand substantially perpendicular to the bridging length 13. If the cutting head 11 is to be insert-moulded into the body 10 and has two or more end portions I Ia, 11 b the bridging length 13 is less important and may be omitted.

It will be seen that the end portions ha and lIb are necessarily bent into an arcuate form and oppose each other to define a circular footprint in plan whereby the cutting head serves as an annular cutter.

The bridging portion 13 is shown as being suitably relatively narrower than it is long, or strip-like, as viewed in plan and seats into a correspondingly shaped channel 14 in a mounting formation 15 at the cutting end of the body 10. Referring again to Figures 7 to 11, the cutting end of the cutting body 10 is generally blanked off by an end waIl 17 but with a central circular aperture 16 and the mounting formation 15 is generally a platform that protrudes from the end wall 17 and which is separated into right and left portions by the channel 14.

On the respective opposing faces of the channel 14 defined by the plafform protrusion 15 portions that face each other there are provided respective ridge-like shoulders 18. The shoulders 18 extend along the channel along each one of the respective opposing walls of the protrusions 15 and are generally ramp-shaped in profile whereby when the bridging length 13 of the cutting head II is pressed down into the channel 14 the bridging length 13 may be pressed to slide over the ramp * II. * IS.

* I I I I I

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* S 1.1 V I I * I S S S I I * V 6 ** * * surface of the shoulders 18 and snap fit beneath them and to be held in place by those shoulders 18.

The central aperture 16 through the end wall 17 may, if desired, be used as a means for inserting a tool down the bore of the body 10 to facilitate demounting of the cutting head 11 if required. However, the cutting head 11 need not be demountable. Amongst benefits of demountability is the ability to readily re-use each independently of the other if one is damaged and also the ability to readily separate the components for waste recycling.

It will further be seen from inspection of the cutting end of the body 10 in Figure 14 that the mounting formation/platform 15 is not simply circular in plan but has instepped/recessed circumferential zones 19 into which the cutting head end portions 11 a, 11 b seat in order to better hold the cutting head captive rotationally relative to the cutter body 10 and resist the torsional forces as the cutter head rotates. Thus it will be seen that the cutting head 11 is held securely in place once fitted and is firmly keyed to the body to rotate with it not only by the seating of the bridging portion 13 of the cutting head 11 within the channel 14 that extends diametrically of the body 10 but also by the fit of the cutting head end portions ha, 11 b within their respective recesses 19 in the mounting formation 15 of the body 10.

Also visible from Figure 3 and 4 are provisions in the body 10 for separate mounting of a handle bar / rod (not shown) that may be inserted through opposing apertures that define a socket. The handle bar is suitably a plastics moulding (or of steel or other suitable material) and, with reference to the Figure 6 embodiment, may be further reinforced in its supporting mounting to the body 10 by provision of extension sleeves/shoulders 21 projecting from the perimeter of each aperture 20. Also visible in Figure 6 is the adaptation of the upper end of the cutting body 10 to have a nut-shaped formation 22 suitable for gripping by a wrench or large spanner to provide additional leverage when screwing down the cutter to cut into the plastics pipe.

A further feature of the tool is provision for storage of the cutting head 11 in the remote end of the cutter body 10 prior to use. In Figure 3 it will be seen that the upper end of the tubular cutter body 10 is of an internal diameter that closely accommodates the external diameter of the cutter head 11 and wherein the cutting * ii. II. * Its

I I I S I I I

S S I SI I I II

S S ItS I * S S e S I I S * 7 III I I S S head 11 is stored with the cutting end/edge/teeth of the cutting head 11 safely housed within the cutter body 10. This provides benefits not only in safety of the packaging of the tool and thereby enabling less padding, encasing or protective materials to be used in the packaging but also simplifies the assembly of the tool in manufacture. The manufacturer can leave the user to install/clip-fasten the cutting head 11 in place and instead simply ship the tool with the cutting head 11 slidingly- mounted in the socket in the remote end of the cutter body 10. The socket is preferably of defined depth having a shoulder or wall at its bottom, but may simply be a part of the internal bore of the tubular body 10.

Claims

* l *I* I *** * a I I I * I I * IS I I II * * I*I S * I * * I S I S I * * S 8 a.. * * CLAIMS

1. A pipe cutter suitable for manual use to cut an opening into a wall of a pipe and which is adapted to be used in combination with a saddle that mounts over the pipe, the cutter having a cutting head and having a moulded plastics body formed with a screw thread that co-operatively engages with a corresponding screw thread of the saddle whereby the cutting head of the cutter may be advanced to cut into the pipe, wherein the cutting head is formed from a sheet of metal or metal alloy or other suitable material, being cut out or pressed out from the sheet and bent to an arcuate cutting shape to cut a circular hole and assembled with the cutter body.

2. A pipe cutter as claimed in Claim 1, wherein the body of the cutter is moulded of plastics to have a pre-formed receiving formation at one end to receive the cutting head and hold it against axial rotation relative to the cutter body.

3. A pipe cutter as claimed in Claim 1, wherein the cutting head is assembled to the cutter body in moulding of the cutter body.

4. A pipe cutter as claimed in Claim 2, wherein the cutting head is folded into a 3- dimensional form having at least two cutting end portions and wherein the cutting end portions are joined by a bridging portion substantially transverse to the cutting end portions.

5. A pipe cutter as claimed in Claim 4, wherein each cutting end portion has a plurality of cutting teeth.

6. A pipe cutter as claimed in any preceding claim, wherein the body of the cutter is formed as a tube.

7. A pipe cutter as claimed in any preceding claim, wherein body of the cutter has a socket extending there across through which a separate rod or bar may be inserted to serve as a handle for turning of the cutter.

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S IS * 0 uS * I S S * * I * I S I S 0 9 IS* S S S S 8. A pipe cutter as claimed in Claim 7, wherein the socket is augmented with lateral projections from the cutter body, providing additional support between the handle rod or bar and the cutter body.

9. A pipe cutter as claimed in Claim 3, wherein the body of the cutter has facets around its outer wall part-way therealong or at one end thereof and which allow for use of a spanner, pliers, wrench or similar means for gripping and turning the cutter if required.

10. A pipe cutter as claimed in Claim 9, wherein the body of the cutter has a nut- shaped moulding or formation at the end of the cutter remote from the cutting head end of the cutter.

11. A pipe cutter as claimed in any preceding claim, wherein the body of the cutter has at its end remote from the cutting head end a socket to receive the cutter head to store the cutter head prior to and/ or after use.

12. A pipe cutter as claimed in Claim 11 wherein the socket accommodates the cutter head therein whereby the cutting end of the cutting head does not project out from the socket.

13. A pipe cutter as claimed in any preceding claim and having an arcuate cutting end portion of the cutting head and a head mounting region of the body with a lateral or circumferential recess to receive the cutting head end portion and firmly hold it against rotation of the head relative to the body as the cutting tool is rotated in use

14. A pipe cutter as claimed in Claim 4 and having a channel to receive the bridging portion that may assist to hold the head against rotation of the head relative to the body as the cutting tool is rotated in use

15. A pipe cutter as claimed in any preceding claim, wherein the cutter is provided with a socket to receive a separate rod or bar as a handle, the rod or bar being provided together with the cutter head and body as a modular assembly kit.

I If, .33 * a.a I 4 4 4 I 3 I I II I 4 II I 3 443 3 3 I * 3 I I I 8 S

16. A pipe cutter as claimed in any preceding claim, wherein the cutting head push fits into a channel across an end wall of the cutting end of the body and is retained by shoulders in the channel.

17. A pipe cutter as claimed in any preceding claim, wherein the head is demountable for maintenance, replacement or re-cycling.

18. A pipe cutter as claimed in Claim 17, wherein the body has a bore whereby a tool may be inserted into the body to demount the head.

19. A pipe cutter as claimed in any preceding claim, wherein the cutter head in its arcuate cutting end defines a recess or bore of the cutting end wherein a cut out ofpipewall of a pipe that is cut out by the cutter in Use mä' bëhëld éntraped in the cutter head and thus withdrawn from the pipe on retraction of the cutter.

19. A pipe cutter as claimed in any preceding claim, wherein the cutter head clip fits to the body, being held in place by at least one shoulder on the receiving formation.

20. A pipe cutter as claimed in any preceding claim, wherein the cutter head in its arcuate cutting end defines a recess or bore of the cutting end wherein a cut out of pipewall of a pipe that is cut out by the cutter in use may be held entrapped in the cutter head and thus withdrawn from the pipe on retraction of the cutter.

Amendments to the claims have been filed as follows 1. A pipe cutter suitable for manual use to cut an opening into a wall of a pipe and which is adapted to be used in combination with a saddle that mounts over the pipe, the cutter having a cutting head and having a moulded plastics body formed with a screw thread that co-operatively engages with a corresponding screw thread of the saddle whereby the cutting head of the cutter may be advanced to cut into the pipe, wherein the cutting head is formed from a sheet of metal or metal alloy or other suitable material, being cut out or pressed out from the sheet and bent to an arcuate cutting shape to cut a circular hole and assembled with the cutter body, wherein the uthng had is folded int 3-dimePiohal form i ving at least Fô ëttiè portions and wherein the cutting end portions are joined by a bridging portion substantially transverse to the cuffing end portions.

4. A pipe cutter as claimed in any preceding claim, wherein each cutting end portion has a plurality of cutting teeth.

5. A pipe cutter as claimed in any preceding claim, wherein the body of the cutter is formed as a tube.

6. A pipe cutter as claimed in any preceding claim, wherein body of the cutter has a socket extending there across through which a separate rod or bar may be inserted to serve as a handle for turning of the cutter.

7. A pipe cutter as claimed in Claim 6, wherein the socket is augmented with lateral projections from the cutter body, providing additional support between the handle rod or bar and the cutter body. I-li

8. A pipe cutter as claimed in Claim 3, wherein the body of the cutter has facets around its outer wall part-way therealong or at one end thereof and which allow for use of a spanner, pliers, wrench or similar means for gripping and turning the cutter if required.

9. A pipe cutter as claimed in Claim 8, wherein the body of the cutter has a nut- shaped moulding or formation at the end of the cutter remote from the cutting head end of the cutter.

10. A pipe cutter as claimed in any preceding claim, wherein the body of the cutter has at its end remote from the cutting head end a socket to receive the cutter head ---te-s-tore the cutter head prior to-and! or after user 11. A pipe cutter as claimed in Claim 10, wherein the socket accommodates the cutter head therein whereby the cutting end of the cutting head does not project out from the socket.

12. A pipe cutter as claimed in any preceding claim and having an arcuate cutting end portion of the cutting head and a head mounting region of the body with a lateral or circumferential recess to receive the cutting head end portion and firmly hold it against rotation of the head relative to the body as the cutting tool is rotated in use 13. A pipe cutter as claimed in Claim I and having a channel to receive the bridging portion that may assist to hold the head against rotation of the head relative to the body as the cutting tool is rotated in use 14. A pipe cutter as claimed in any preceding claim, wherein the cutter is provided with a socket to receive a separate rod or bar as a handle, the rod or bar being provided together with the cutter head and body as a modular assembly kit.

15. A pipe cutter as claimed in any preceding claim, wherein the cutting head push fits into a channel across an end wall of the cutting end of the body and is retained by shoulders in the channel.

16. A pipe cutter as claimed in any preceding claim, wherein the head is demountable for maintenance, replacement or re-cycling.

17. A pipe cutter as claimed in Claim 16, wherein the body has a bore whereby a tool may be inserted into the body to demount the head.

18. A pipe cutter as claimed in any preceding claim, wherein the cutter head clip fits to the body, being held in place by at least one shoulder on the receiving formation.