GB2071539A

GB2071539A - Method of Swaging Tubes and Pipes Using Corrugation Techniques

Info

Publication number: GB2071539A
Application number: GB8002654A
Authority: GB
Original assignee: Clements G M
Current assignee: Clements G M
Priority date: 1979-01-25
Filing date: 1980-01-25
Publication date: 1981-09-23

Abstract

The method alters the external dimensions of the cross-section of a tube for a short distance along from the end, such that the end is modified to form a new cross-section of reproduceable shape and dimension. The cross-section remains substantially the same except for dimensions but will differ from normal swaging by the fact that the extra material or unwanted material has been displaced by the formation of corrugations or folds thus allowing the reduction in dimension to take place. To avoid high stresses especially at corners rollers are used. The avoidance of 'scuffing' allows this method to be ideally suited for the reduction of pre-coated tube and pipe of non-round section to be swaged. <IMAGE>

Description

SPECIFICATION Method of Swaging Tubes and Pipes Using Corrugation Techniques.

Swaging is the act of reducing the diameter of a tube or pipe, normally the cross-section of the pipe is round. There are many important objectives in doing this; perhaps the best example is to reduce one tube such that it is a sliding fit into a mating tube such as a TENT POLE: alternatively a long pole might need to be tapered in order to save on material and produce a more aethetically pleasing shape such as a LAMP POST. Swaging of round tube has been undertaken for many years with several different methods of production.

The Swaging of Square and rectangular tube especially with sharp corner radii presents its own problems and no satisfactory method exists for the rapid and repeatable and inexpensive production of this type of tube.

The inventors have developed a technique for forming tubes of this type using corrugations along the surfaces (4) in order to cause the shape of the tube to reduce thereby reproducing the approximate shape but with smaller dimensions.

The corners of the tube itself (1) must be controlled inwards by the use of rollers (8) whilst the corrugations (2) are produced by another set of rollers (6). In order that the shape demanded is maintained and the tube does not collapse inwards a centre mandrel 1 (7) is required. The rollers (6) and (8) are mounted into a housing (9) which moves along the tube with the mandrell (7). Such an arrangement would be able to produce a reduction of any length along the tube within the limitations of the machine being used.

There are no limitations on the material to be used provided that the material has sufficient ductility to be worked.

The kind of joints between two tubes as shown at (5) is envisaged. Such a form should be produced at production rates similar to the production of swages produced in round tube.

Claim

The Method of Swaging Tubes and Pipes using corrugation Techniques requires the altering of the external dimensions of the tube such that the final cross-section of the swaged portion is the desired shape allowing for local deviations due to the presence of the corrugations.

The corrugations are defined as: folds, wrinkles, distortions, waves and any term which can be used to describe such forms in the tube wall. The corrugations do not necessarily have to be caused solely by the rollers or dies present; that is folds may occur, which are naturally occuring when say the corner dies (8) are used alone.

The final shape of the swaged form does not necessarily have to be a reproduction of the original tubular cross-section; that is, it may be desirable to produce a square cross-section on a rectangular tube.

The method can encompass tubes of any shape; external dimensions, wall thickness, material, whether pre-coated, having a prior 'heat treatment or not.

The method can be done either hot or cold with or without lubricants neither quality having any bounds providing it is necessary for the swage to be performed.

The method can be used for any application, the use of the tube defining only which of the above aspects mentioned in lines 6-1 9 are needed, and with no limitations on the actual usage.

The design of the roller housing may or may not be such as to allow the swage to be performed in either direction, that is when the die is being pushed or pulled onto the tube or when it is being removed or a combination of both that is a partial swage forwards and a partial swage to complete on return.

Should the corrugations not be visible, which is a condition occuring when a soft material is used and the compressive forces are high enough to cause the material to thicken without visible corrugations the swage shall still be said to be caused by this method, provided that the form is produced with a die and roller combination or rollers but not with a solid die, unless such a die is used to produce corrugations as previously described.

The method does not stipulate dimensional tolerances on the finished component as these will be determined by (a) the use to which the component is put and (b) whether any further finishing such as painting, plating, plastic coating, adhesive or any other medium is required.

Tolerances on the tools are determined by (a) ths use to which the component is to be put (b) the aethetic appearance, (c) any further requirement of the specification of the component (d) any tolerance which is required to enable the component to be a manufacturing proposition.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

SPECIFICATION Method of Swaging Tubes and Pipes Using Corrugation Techniques.

Swaging is the act of reducing the diameter of a tube or pipe, normally the cross-section of the pipe is round. There are many important objectives in doing this; perhaps the best example is to reduce one tube such that it is a sliding fit into a mating tube such as a TENT POLE: alternatively a long pole might need to be tapered in order to save on material and produce a more aethetically pleasing shape such as a LAMP POST. Swaging of round tube has been undertaken for many years with several different methods of production.

The Swaging of Square and rectangular tube especially with sharp corner radii presents its own problems and no satisfactory method exists for the rapid and repeatable and inexpensive production of this type of tube.

The inventors have developed a technique for forming tubes of this type using corrugations along the surfaces (4) in order to cause the shape of the tube to reduce thereby reproducing the approximate shape but with smaller dimensions.

The corners of the tube itself (1) must be controlled inwards by the use of rollers (8) whilst the corrugations (2) are produced by another set of rollers (6). In order that the shape demanded is maintained and the tube does not collapse inwards a centre mandrel 1 (7) is required. The rollers (6) and (8) are mounted into a housing (9) which moves along the tube with the mandrell (7). Such an arrangement would be able to produce a reduction of any length along the tube within the limitations of the machine being used.

There are no limitations on the material to be used provided that the material has sufficient ductility to be worked.

The kind of joints between two tubes as shown at (5) is envisaged. Such a form should be produced at production rates similar to the production of swages produced in round tube.

Claim

The Method of Swaging Tubes and Pipes using corrugation Techniques requires the altering of the external dimensions of the tube such that the final cross-section of the swaged portion is the desired shape allowing for local deviations due to the presence of the corrugations.

The corrugations are defined as: folds, wrinkles, distortions, waves and any term which can be used to describe such forms in the tube wall. The corrugations do not necessarily have to be caused solely by the rollers or dies present; that is folds may occur, which are naturally occuring when say the corner dies (8) are used alone.

The final shape of the swaged form does not necessarily have to be a reproduction of the original tubular cross-section; that is, it may be desirable to produce a square cross-section on a rectangular tube.

The method can encompass tubes of any shape; external dimensions, wall thickness, material, whether pre-coated, having a prior 'heat treatment or not.

The method can be done either hot or cold with or without lubricants neither quality having any bounds providing it is necessary for the swage to be performed.

The method can be used for any application, the use of the tube defining only which of the above aspects mentioned in lines 6-1 9 are needed, and with no limitations on the actual usage.

The design of the roller housing may or may not be such as to allow the swage to be performed in either direction, that is when the die is being pushed or pulled onto the tube or when it is being removed or a combination of both that is a partial swage forwards and a partial swage to complete on return.

Should the corrugations not be visible, which is a condition occuring when a soft material is used and the compressive forces are high enough to cause the material to thicken without visible corrugations the swage shall still be said to be caused by this method, provided that the form is produced with a die and roller combination or rollers but not with a solid die, unless such a die is used to produce corrugations as previously described.

The method does not stipulate dimensional tolerances on the finished component as these will be determined by (a) the use to which the component is put and (b) whether any further finishing such as painting, plating, plastic coating, adhesive or any other medium is required.

Tolerances on the tools are determined by (a) ths use to which the component is to be put (b) the aethetic appearance, (c) any further requirement of the specification of the component (d) any tolerance which is required to enable the component to be a manufacturing proposition.