GB2285594A - Bevel cutter - Google Patents

Abstract

A bevel cutter comprises an elongate tubular guide member (2) which is adapted to be received on or in a length of pipe. A cutter arm (7) is coupled to the guide member (2) such that it can be rotated manually about the longitudinal axis of the guide member, and a cutting blade (14) is mounted on the cutter arm (7) for forming a bevel on an end of said pipe when the cutter arm (7) is so rotated. The handle (16) may be coupled to the cutter arm via a ratchet mechanism. The blade (14) may be replaceable and angularly and radially adjustable. <IMAGE>

Description

DESCRIPTION BEVEL CUTTER This invention relates to the jointing of plastic piping, and more specifically to a bevel cutter for use in cutting a bevel on the end of a pre-cut length of plastic piping to enable it to be fitted in a mating socket.

Plastic piping is commonly, but by no means exclusively, used in plumbing systems. A wide variety of fittings are available for forming joints, elbows, U-bends, etc. in plastic piping. A widely used type of fitting has mating sockets into which a bevelled end of a length of plastic pipe is inserted and includes means, typically a deformable sealing ring, for forming a watertight seal on the piping. To ensure that a truly watertight seal is achieved, and to allow easy insertion of the plastic piping, the bevelled end needs to be free from burrs, have a smooth surface finish and be of uniform shape.

There are several commonly used methods for producing such a bevelled end, though no method has gained universal acceptance.

The cut end of the piping may, for example be dressed by hand using a file or rasp. However, the plastic of which the piping is made is not easily worked with hand tools, and it is difficult by this method to achieve the necessary smooth surface finish and uniformity of shape. Hand dressing is also a time consuming process.

Electric machine tools are available, in which the piping is clamped while the bevel is machined.

Portable grinding equipment may also be used. The electric tools used are typically expensive and not highly portable.

Piping may be purchased in ready prepared lengths, with finished ends, but mistakes in measuring the required lengths, when the pipe cannot be offered up and trimmed, lead to high wastage.

It is therefore an object of the present invention to provide a relatively cheap, simple and easily portable means for forming a bevel on the end of a length of piping in a short time and without a need for the operator to have special manual skills.

In accordance with the present invention, a bevel cutter comprises a guide member, adapted to be received by a length of pipe, and a cutting blade which, when said guide member is received by said pipe, is contactable with said pipe and rotatable in a circular arc relative thereto.

The blade is held at a constant angle relative to an end of the pipe so that, when the blade is brought into contact with that end of the pipe and is rotated relative to it, a bevel is cut.

Specific embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which Figures 1 and 2 are diagrammatic perspective views of two embodiments of bevel cutters in accordance with the present invention.

In this embodiment, the guide member is in the form of a tubular guide 2 whose external diameter is equal to or slightly less than the internal diameter of the plastic piping to be bevelled, so that the tubular guide 2 can be slid into the piping.

Diagonal cross members 6 are provided at both ends of the tubular guide 2. A bearing support rod 4 extends along the longitudinal axis of the guide 2 and is fixedly retained in holes in the cross members 6, projecting axially beyond the tubular guide 2 at one end thereof.

A cutter arm 7 is pivotally mounted on the projecting end 4a of the bearing support rod 4, such as to be constrained to rotate about the longitudinal axis of the tubular guide only. An outer portion of the cutter arm 7 extends radially beyond the outer surface of the tubular guide 2.

Two mounting brackets 8 are formed on or mounted to the outer portion of the cutter arm 7. A threaded rod 10 which runs parallel to the cutter arm 7, passes through holes in both of the mounting brackets 8 and engages threadedly therewith . The radially outer end of the threaded rod 10 (relative to the axis of the tubular guide 2) is provided with a knurled head 12 while a cutting blade 14 is rigidly attached to its inner end.

The cutting blade 14, which has a straight angled cutting edge, can be advanced or withdrawn in a radial direction by turning the threaded rod 10 using the knurled head 12, so varying the depth of the bevel to be cut. Locking nuts 18, disposed on the threaded rod 10, may be brought into abutment against the mounting brackets 8 to prevent the threaded rod 10 being turned and to lock the cutting blade 14 in position.

An elongate cranking handle 16 of circular section is rotatably mounted on the outer end of the cutter arm 7, so that it can adopt an attitude in which it lies parallel to the longitudinal axis of the tubular guide 2.

Using this embodiment of the invention, a bevel is cut as follows.

The guide drum 2 is inserted into the plastic piping, bringing the cutting blade 14 into contact with an end of the pipe. The position of the cutting blade 14 relative to the pipe, and thus the size of the bevel to be cut, may then be adjusted by turning the threaded rod 10, after which the cutting blade is locked in position using the locking nuts 18. The operator then holds the pipe in one hand while rotating the cutter arm 7, using the cranking handle 16, with the other hand, simultaneously advancing the guide drum 2 into the pipe to cut the bevel.

The bevel is thus cut without machine tools and without the time consuming necessity of clamping the pipe in place.

The cutting blade 14 is preferably removably mounted to provide for sharpening and changing of the cutting blade.

Referring now to Figure 2, there is shown a modified embodiment in which the simple direct drive for rotating the blade in the embodiment of Figure 1 is replaced by a ratchet drive. Identical parts in the embodiment of Figure 2 have been given the same reference numerals as in Figure 1. The principal difference is that, the blade-carrying arm 7 is rigidly coupled to a rotatable support rod 4a and, instead of attaching the handle 16 directly to the radially outer end of the blade-carrying arm 7, the handle 16 is carried by a further radial arm 20 which is coupled to the support rod 4 by way of a conventional ratchet device 22 (not shown in detail) whereby the support rod 4, and with it the bladecarrying arm 7, can be rotated via the ratchet device by small angular displacements of the handle 16. This is particularly useful for achieving a bevelling operation in conditions where space restrictions do not allow full 360O turning of the handle 16. In accordance with conventional designs of ratchet mechanisms, a reversing pin 24 enables the drive direction of the mechanism to be altered whereby bevelling can be performed in both rotational directions.

Preferably, the mounting and adjusting mechanism for the blade is such that the angle of the blade is fixed. This can be achieved by arranging for the rod 10 to be splined, for example in the mounting brackets 8, so that the rod 10 is displaceable longitudinally but not rotationally relative to these mounting brackets 8.

The invention is not restricted to the embodiments illustrated and described above.

Alternative embodiments will be apparent to one skilled in the art.

Claims (15)

1. A bevel cutter comprising a guide member, adapted to be received by a length of pipe, and a cutting blade which, when said guide member is received by said pipe, is contactable with said pipe and rotatable in a circular arc relative thereto.

2. A bevel cutter according to claim 1 wherein said cutting blade is arranged to be rotatable, when said guide member is received by said pipe, only about the longitudinal axis of said pipe.

3. A bevel cutter according to claim 1 or 2 further comprising a handle by which said cutting blade may be rotated.

4. A bevel cutter according to any preceding claim wherein said cutting blade may be advanced or withdrawn in a radial direction.

5. A bevel cutter according to any preceding claim wherein said guide member comprises an elongate component adapted to be slidably received in said pipe.

6. A bevel cutter according to claim 5 wherein said blade is mounted on a cutter arm which extends perpendicularly to, and is rotatable about, the longitudinal axis of the guide member.

7. A bevel cutter a claimed in claim 6, wherein the cutter arm carrying the blade is adapted to be rotated about the longitudinal axis of the guide member by means of a ratchet mechanism.

8. A bevel cutter as claimed in claim 7, wherein the cutter arm is connected to a support rod extending longitudinally of the guide member and the ratchet mechanism is arranged to angularly rotate the support rod and thence the cutter arm connected thereto.

9. A bevel cutter according to claim 6 wherein said cutter arm is pivotally mounted on said guide member.

10. A bevel cutter according to any of claims 6 to 9, wherein said cutting blade is mounted on a threaded rod which threadedly engages with one or more mounting brackets attached to said cutter arm.

11. A bevel cutter according to any of claims 1, 2, 3 and 4 wherein said guide member has an internal aperture adapted to receive said pipe.

12. A bevel cutter according to any preceding claim, wherein the angle between the cutting edge of said cutting blade and the plane of rotation of said cutting blade may be adjusted.

13. A bevel cutter according to any preceding claim wherein said blade is removable.

14. A bevel cutter comprising an elongate guide member which is adapted to be received on or in a length of pipe whose end is to be bevelled, a cutter arm coupled to the guide member such that it can be rotated manually about the longitudinal axis of the guide member, and a cutting blade mounted on the cutter arm for forming a bevel on an end of said pipe when the cutter arm is rotated.

15. A bevel cutter substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawing.