GB2378913A

GB2378913A - Portable hand tools

Info

Publication number: GB2378913A
Application number: GB0217809A
Authority: GB
Inventors: Peter Graham
Original assignee: IMI Yorkshire Fittings Ltd
Current assignee: Aalberts Integrated Piping Systems Ltd
Priority date: 2001-08-03
Filing date: 2002-08-01
Publication date: 2003-02-26
Anticipated expiration: 2022-08-01
Also published as: GB0217809D0; GB2378913B; GB0118960D0

Abstract

A portable hand tool 1 for preparing the end 2 of a metal tube 3 between 10mm and 55mmm outside diameter for plumbing and like purposes. The tool 1 comprises a cup member 4 whose external profile has a first closed end 5 and a second open end 6, and whose internal profile is defined by a blind bore 10. The bore 10 has a first cylindrical bore portion 11 at the open end 6 connected by a radiussed corner 12 to a radially-extending shoulder 13 which forms at least part of the closed end of the bore 10. The arrangement is such that when a tube end 3 is inserted into the cylindrical bore portion 10 to abut the shoulder 13, a force applied externally to the first end 5 acts to deform the tube end 3 at the radiussed corner 12 to produce a smooth and chamfered surface.

Description

PORTABLE HAND TOOLS This invention relates to portable hand tools for preparing ends of tubes, particularly copper tubes used for plumbing.

In plumbing it is of course necessary to connect tubes together by coupling devices. Tubes are usually cut on-site by a plumber, and may be cut using a pipe-cutter or just a hacksaw. Where the coupling device uses solder to connect to the tube, the profile of the cut end does not matter greatly. However, where the coupling device is of the press fit type, or the push fit type, both of which use a sealing member such as an 0-ring, to seal between the outside of the tube and the inside of the coupling device, the tube end needs to be smooth and chamfered, so as not to damage the O-ring as the tube end is inserted into the coupling device.

A suitable end can be produced by using a rotary pipe-cutter with a sharp wheel, but this can be expensive to purchase, and time-consuming to use.

Other tube-cutting methods require a final preparation step. If a hacksaw is used to cut the tube, burrs must be removed from the end, and a chamfer applied. Cutting the tube using a straight pipe-cutter also requires a chamfer to be applied. A deburring tool is used for this final preparation. The tube end is inserted into the deburring tool, which has one or more blades acting to produce a smoothed chamfered end as the tube is rotated. Using the deburring tool is time-consuming, and tends to produce slivers of metal, which must be removed from the tube end to ensure that they cannot damage the O-ring. The deburring tool may also produce a chattered finish, which is not completely smooth and may also damage the O-ring.

According to a first aspect of the present invention, a portable hand tool for preparing the end of a metal tube between 10mm and 55mm outside

diameter comprises a cup member whose external profile has a first closed end and a second open end, and whose internal profile is defined by a blind bore having a first cylindrical bore portion at the open end connected by a radiussed corner to a radially-extending shoulder forming at least part of the closed end of the bore, the arrangement being such that, when a tube end is inserted into the cylindrical bore portion to abut the shoulder, a force applied externally to the first end acts to deform the tube end at the radiussed corner to produce a smooth and chamfered surface.

The portable hand tool is easy and quick to use, as the tube end is simply inserted into the tool, whose closed end is then hit with a hammer or other suitable tool. The tube end is thereby prepared to the correct shape, without creating slivers of metal. Furthermore, the tube end is always completely smooth, and free from chattering. The final preparation step using the tool according to the invention therefore results in a tube end which is immediately ready to join to a coupling device, and which will not damage an O-ring or other sealing member in the device.

A further advantage is that, because the tube end is always the correct shape, the force needed to insert the tube end into the coupling device is substantially constant, and not excessive.

Preferably the first closed end of the external profile of the cup member is provided as a first substantially cylindrical portion of smaller diameter, the second open end is provided as a second substantially cylindrical portion of larger diameter. The first and second portions are connected by an intermediate frustoconical portion. The smaller diameter portion at the closed end ensures that the force is applied evenly round the tool when it is hit.

Preferably the blind bore is of stepped outline, with the radially-extending shoulder leading to a second cylindrical bore portion of smaller diameter than the first bore portion, at the closed end of the bore.

This has the advantage that a portable hand tool for a smaller diameter tube can easily be nested inside one for a larger diameter tube, as the first cylindrical portion of the external profile of the smaller tool can be received in the second bore portion of the larger tool. A nesting set of tools can therefore be provided, which is of advantage to the user, as they can all be kept together easily.

According to a second aspect of the present invention, we provide a set of two or more portable hand tools according to the first aspect of the invention, each hand tool being for preparing a different diameter of metal tube, and being adapted so that a hand tool for a tube of smaller diameter nests inside a hand tool for a tube of larger diameter.

The second aspect of the invention therefore provides a nesting set of tools, which is advantageous to the user, as providing a set for different tube sizes, which can easily be kept together. Preferably the portable hand tools are adapted to nest by providing the first closed end of smaller diameter, and a step in the blind bore to receive the closed end of a smaller size tool.

Embodiments of both aspects of the invention are illustrated in the accompanying drawings, in which: Figure 1 shows a cross-section through a metal tube and portable hand tool according to the first aspect of the invention after preparation of the tube end;

Figure 2 shows a cross-section through a modified tool; Figure 3 is a perspective view of three tools of different sizes; and Figure 4 shows the tools of Figure 3 in a nested position.

Figure 1 shows a portable hand tool 1 for final preparation of the end 2 of a metal tube 3 (e. g. copper tube) between 10 mm and 55 mm outside diameter for plumbing and like purposes. The tool 1 prepares the end 2 by smoothing and chamfering it, so that it is suitable for use with a tube coupling device (not shown) of the press fit or push fit type, where an 0ring is used as a sealing member to seal between the outside of the tube 3 and the inside of the coupling device. It is necessary with these tube coupling devices for the tube end 2 to be smooth and chamfered, so that the O-ring is not damaged as the tube end is inserted into the coupling device. The portable hand tool 1 prepares the tube end 2 without creating swarf (slivers of metal), and can be used regardless of how the tube end 2 has been cut (by hacksaw or pipe-cutter).

As shown in Figure 1, the tool 1 comprises a metal cup member 4. The cup member 4 has a first closed end 5 and a second open end 6 into which the tube end 2 can be inserted.

Externally the first end 5 has a cylindrical portion 7 of smaller diameter, the second end 6 has a cylindrical portion 8 of larger diameter, and the two portions 7,8 are joined by an intermediate frustoconical portion 9.

The internal profile of the cup member 4 is defined by a blind bore 10, with a first cylindrical bore portion 11 at the open end 6 terminating in a radiussed shoulder 12 connecting to a radial surface 13 forming the closed end of the bore 10. The inside diameter of the first bore portion is

determined by the outside diameter of the metal tube: it is necessary for the tube to fit snugly in the bore portion 11.

In use, the user inserts a tube end 2 into the bore portion 11 until it abuts the shoulder 12. The tube end 2 may have burrs if it has been cut with a hacksaw. If it has been cut with a pipe-cutter it may not have burrs, but may have other imperfections. The user holds the tube 3 and then hits the closed end 5 with a copper hammer or other suitable tool. This causes the tube end 2 to deform, following the contour of the radiussed shoulder 12, so that it assumes the smoothed and chamfered form shown in Figure 1. The tube 3 is then removed from the tool 1, and is ready for insertion into a coupling device without any further preparation, as no swarf has been generated. The tool ensures that the tube ends 2 are prepared consistently, and are such that they are easy to insert into the coupling device. It is also very easy and quick to use.

The provision of the smaller diameter portion 7 at the closed end 5 ensures that the force from the hammer is applied evenly to the tube end 2. If the closed end 5 were of the same diameter as the larger portion 8, it would be easier to strike the closed end 5 off centre, so that the tube end 2 would not be deformed evenly.

Figure 2 shows a modification of the portable hand tool 1 of Figure 1 and corresponding reference numerals have been applied to corresponding parts.

In Figure 2 the profile of the blind bore 10 is modified at its closed end.

Thus, the blind bore 10 is stepped, with the radial surface 13 being annular, and leading to a second cylindrical bore portion 15 of smaller diameter than the first bore portion 11. In fact, the radial surface 13 is connected to the bore portion 15 by a small angled surface 16. The

diameter of the second bore portion 15 is less than the outside diameter of the closed first end 5. It will also be noted that the open end of the first bore portion 11 is slightly chamfered at 17, to aid insertion of the tube end 2.

The tool of Figure 2 is used in the same way as that of Figure 1, with the tube end 2 being deformed at the radiussed shoulder 12.

The provision of the second bore portion 15 makes it easier to nest a smaller tool 1 inside a larger one, as the closed end 5 of the smaller tool will fit into the second bore portion 15. Figures 3 and 4 show three tools 1 of different sizes.

Figure 3 shows the tools 1 separated, and Figure 4 shows them nested inside each other, with the closed end 5 of the smallest tool fitting into the second bore portion 15 of the middle size tool, and the closed end 5 of the middle size tool fitting into the second bore portion 15 of the largest tool.

It is extremely convenient for the tools to nest in this way, as they are easy to keep together. The user may buy a selection of tools 1 of the sizes that he or she uses most often, and nest them together for storage.

Claims

CLAIMS 1. A portable hand tool for preparing the end of a metal tube between 10mm and 55mm outside diameter comprises a cup member whose external profile has a first closed end and a second open end, and whose internal profile is defined by a blind bore having a first cylindrical bore portion at the open end connected by a radiussed corner to a radially-extending shoulder forming at least part of the closed end of the bore, the arrangement being such that, when a tube end is inserted into the cylindrical bore portion to abut the shoulder, a force applied externally to the first end acts to deform the tube end at the radiussed corner to produce a smooth and chamfered surface.
2. A portable hand tool according to Claim 1, in which the first closed end of the external profile of the cup member is provided as a first substantially cylindrical portion of smaller diameter and the second open end is provided as a second substantially cylindrical portion of larger diameter.
3. A portable hand tool according to Claim 2, in which the first and second portions being connected by an intermediate frustoconical portion.
4. A portable hand tool according to any preceding claim, in which the blind bore is of stepped outline, with the radially-extending shoulder leading to a second cylindrical bore portion of smaller diameter than the first bore portion, at the closed end of the bore.
5. A set of two or more portable hand tools as claimed in any preceding claim, each hand tool being for preparing a different

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diameter of metal tube and being adapted so that a hand tool for a tube of smaller diameter nests inside a hand tool for a tube of larger diameter.
6. A set of portable hand tools according to Claim 5, in which the portable hand tools are adapted to nest by providing the first closed end of smaller diameter, and a step in the blind bore to receive the closed end of a smaller sized tool.
7. A portable hand tool substantially as described herein with reference to and as illustrated in Figures 1 and 2 of the accompanying drawings.
8. A set of two or more portable hand tools substantially as described herein with reference to and as illustrated in Figures 3 and 4 of the accompanying drawings.