GB2048144A

GB2048144A - Expander tool for pipe jointing

Info

Publication number: GB2048144A
Application number: GB7915346A
Authority: GB
Original assignee: Oskinen K L J
Current assignee: Oskinen K L J
Priority date: 1979-05-03
Filing date: 1979-05-03
Publication date: 1980-12-10
Also published as: GB2048144B

Abstract

The tool has a head (2) which can be passed through an opening in a pipe (4) and rotated to expand the pipe material around the opening into a collar (12). Threaded onto the shank (3) of the head (2) is a nut (1) which presses a contact ring (5) onto the pipe during the deforming operation. According to the invention a spring (6) is interposed between the nut (1) and contact ring (5) and serves to prevent rotation of the nut (1) with the shank (3). <IMAGE>

Description

SPECIFICATION An improved expander tool for use in pipe jointing This invention relates to an improved expander tool for use in pipe jointing.

In Patents Nos 1,446,616 and 1,155,224 there are described expander tools having a hook shaped head at one end of a threaded shank engaged by an internally threaded sleeve. The head is passed through a hole in a pipe, the sleeve is screwed down into contact with the pipe and then the head is rotated by means of the shank to deform the material of the pipe around the hole into the sleeve to provide an outstanding collar around the hole which facilitates jointing a branch pipe.

Among the objects of the present invention are to improve the previously known tool above described by dividing the sleeve into flexibly connected contact and nut portions, thereby facilitating the use of the tool and ensuring that, in use, the sleeve is firmly restrained against rotation with the shank.

According to the invention there is provided an expander tool comprising a forming head integral with one end of a threaded shank and an internally threaded sleeve engaging the threads on the shank and contactable with a pipe when the head is passed through an opening in the pipe so that on rotation of the shank the head will deform the material of the pipe into the sleeve to form a collar around the opening, wherein the sleeve comprises a nut portion engaging the screwthreads of the shank, a contact portion contactable with the pipe when the head is passed through an opening in the pipe and a flexible coupling between the nut and contact portion adapted to restrain rotation of the nut portion with the shank when the latter is rotated in the deforming operation.

The flexible coupling may comprise a helical spring which closely embraces the nut portion, one end of the spring being connected to the contact portion. Alternatively, the flexible coupling may comprise a helical spring which is connected at one end to the nut portion and at its other end to the contact portion. In the latter construction the contact portion may have a radially inwardly opening annular recess to accommodate the associated end portion of the spring, and the said associated end portion of the spring may be bent to lie in the plane of the recess.

The contact portion of the sleeve may be disconnectable from the flexible coupling for replacement by a contact portion of different internal dimensions.

The end face of the contact portion remote from the nut portion may be formed with diametrically opposed recesses dimensioned to straddle the outer surface of a pipe to prevent rotation of the contact portion relative to the pipe.

Each said recess may be three sided.

Preferred embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a side elevation, partly in section, of a tool in accordance with the invention engaged in a hole in a pipe.

Figure 2 is a perspective view from below, with parts broken away, of the tool shown in Figure 1, and Figure 3 is a view similar to Figure 2 of an alternative tool in accordance with the invention, The tool shown in Figures 1 and 2 comprises a hook-shaped head 2 adapted to be passed through a preformed hole in a pipe 4. A shank 3, with which the head 2 is integral at one end, is externally screw-threaded to be engaged by an internally screw-threaded nut 1. With the nut 1 screwed down the shank 3 until a contact ring 5 firmly abuts the outer surface of the pipe 4 the shank 3 is rotated (e.g. by a spanner engaging its polygonal exposed end) so that the head 2 deforms the material of the pipe 4 around the hole into the contact ring 5 to form an upstanding collar around the hole, as shown as 12 in Figure 1.

This is subsequently used in fixing a branch pipe at right-angles to the pipe 4 as described in Patent No. 1,446,616.

In accordance with the present invention the nut 1 and contact ring 5 are flexibly coupled together by a helical spring 6 which surrounds a reduced-diameter portion of the nut 1 and is connected at 10 at one end to the contact ring 5.

In use of the tool, after the head 2 has been passed through a hole in the pipe 4 the nut 1 is screwed down the shank 3 toward the pipe, rotating it in the direction of arrow b in Figure 2, until the contact ring 5 is pressed firmly against the pipe and the spring 6 is in compression between the contact ring 5 and nut 1. When subsequently the shank 3 is rotated in the direction of arrow a so that the head 2 deforms the material of the pipe 4 into the contact ring 5, as shown in Figure 1, the spring 6 prevents rotation of the nut 1 with the shank 3. On completion of the deforming operation the nut 1 is counter-rotated in the direction of arrow c, slackening the spring 6 and allowing withdrawal of the head 2 from the hole.

In the alternative embodiment of the invention shown in Figure 3 the helical spring 7 has fewer turns than the spring 6 and is fixed at one end to the nut and at its other end to the contact ring 5.

Preferably the connection of the spring 7 to the contact ring 5 is releasable to permit the contact ring 5 to be replaced by one of different internal dimensions, so that the same tool can be used on pipes of different wall thickness. This can be achieved by bending one end portion of the spring 7 to lie in a plane perpendicular to the axis of the spring and trapping this end portion in a circumferential recess 9 in the inner periphery of the contact ring 5.

The end face of the contact ring 5 remote from the nut 1 is formed with diametrically opposite recesses 8 to straddle the pipe exterior and prevent rotation of the contact ring 5 relative to the pipe 4. Preferably and as shown these recesses 8 are three-sided.

It will be appreciated that the flexible coupling between the nut 1 and contact ring 5 need not be in the form of a helical spring but might, for example, take the form of a frustro-conical annular plate spring.

Alternative or additional ways of connecting either a helical or a plate spring to the contact ring 5 are to insert a lug or end portion of the spring into a radial bore in the contact ring 5.

Claims

1. An expander tool comprising a forming head integral with one end of a threaded shank and an internally threaded sleeve engaging the threads on the shank and contactable with a pipe when the head is passed through an opening in the pipe so that on rotation of the shank the head will deform the material of the pipe into the sleeve to form a collar around the opening, wherein the sleeve comprises a nut portion engaging the screwthreads of the shank, a contact portion contactable with the pipe when the head is passed through an opening in the pipe and a flexible coupling between the nut and contact portion adapted to restrain rotation of the nut portion with the shank when the latter is rotated in the deforming operation.

2. A tool as claimed in claim 1, wherein the flexible coupling comprises a helical spring which closely embraces the nut portion, one end of the spring being connected to the contact portion.

3. A tool as claimed in claim 1, wherein the flexible coupling comprises a helical spring which is connected at one end to the nut portion and at its other end to the contact portion.

4. A tool as claimed in claim 3, wherein the contact portion has a radially inwardly opening annular recess to accommodate the associated end portion of the spring.

5. A tool as claimed in claim 4, wherein the said associated end portion of the spring is bent to lie in the plane of the recess.

6. A tool as claimed in any one of the preceding claims, wherein the contact portion of the sleeve is disconnectable from the flexible coupling for replacement by a contact portion of different internal dimensions.

7. A tool as claimed in any one of the preceding claims, wherein the end face of the contact portion remote from the nut portion is formed with diametrically opposed recesses dimensioned to straddle the outer surface of a pipe to prevent rotation of the contact portion relative to the pipe.

8. A tool as claimed in claim 7, wherein each said recess is three sided.

9. An expander tool substantially as herein described with reference to and as shown in Figures 1 and 2 or Figure 3 of the accompanying drawings.