GB2270021A

GB2270021A - Joining tubular components

Info

Publication number: GB2270021A
Application number: GB9218103A
Authority: GB
Inventors: Anthony Bouncer
Original assignee: VERSADUCT SHEET METAL Ltd
Current assignee: VERSADUCT SHEET METAL Ltd
Priority date: 1992-08-26
Filing date: 1992-08-26
Publication date: 1994-03-02
Also published as: GB9218103D0

Abstract

A joggle is formed at one end of a first tubular component and a flange is then formed at one end of a second tubular component by working the components, in sequence, by means of a first pair of rolls 14, 15. During working, the mutual inclination of respective axes of the rolls is varied. The flange is then placed in the joggle and the joggle is worked by a second pair of rolls 28, 29. During working of the joggle, the mutual inclination of respective axes of the rolls 28 and 29 is varied. <IMAGE>

Description

Title: Method of joining and apparatus for use in the method Description of Invention The present invention relates to joining of tubular components end-toend. The invention has been developed primarily for use in connecting end-toend components of ducting which is generally circular in transverse cross section and has a diameter in the range 250 to 1000mm. Such ducting is usually formed from sheet metal, for example galvanised steel strip.

The invention is useful in the production of bends to be incorporated in ducting. It is usual to assemble a bend from a number of tubular components, each of which is tapered in a direction from a position at one side of a longitudinal axis to a position at an opposite side of the axis. These tapered members are generally referred to as segments. The overall length of a segment, that is the length measured at the side of the axis where the length is greatest, is typically less than the diameter of the segment. A 900 bend typically comprises at least three, tapered segments and may further include relatively short, nontapered collars, all united into a single assembly by joining successive members of the assembly together. The length of a collar may be considerably less than the radius of the collar.

According to a first aspect of the present invention, there is provided a method of joining end-to-end first and second tubular components wherein there is formed on the first component at one end thereof by bending a radially outwardly projecting flange, there is formed on the second component at one end thereof by bending a radially outwardly projecting joggle, the flange is seated in the joggle to form an assembly comprising the first and second components and the joggle is bent around the flange to trap the flange between the leaves of a two-leaf flange formed from the joggle, the method being characterised in that at least one of the assembly and the components is worked between a pair of rolls which rotate about respective, mutually inclined axes and in that the inclination of the axis of one roll relative to the axis of the other roll is varied during working.

It will be understood that it is also necessary for the separation between the rolls of the pair to be decreased during working, in order to gradually form the material of one or both of the first and second components to the required shape by bending. We have found that relative movement of the rolls during working which involves both mutual approach of the rolls towards each other and variations in the inclination of the respective axes of the rolls to each other is advantageous, as compared with relative movement of the rolls which is simple straight-line reciprocation, without any change in angular relation.

By a joggle is meant herein a formation at one end of a tubular component which comprises both a radially outwardly projecting portion and an axially extending portion. A step is an alternative description for a joggle.

In the preferred method, the first flange and the joggle are formed in succession by the same pair of rolls working the first component and the second component respectively. The position of one of the rolls relative to the other is preferably adjusted along its axis between working the first component and working the second component. Such adjustment can be effected relatively quickly, as compared with substitution of a first pair of rolls by a second pair of rolls which will generate a formation different from the formation generated by the first pair of rolls.

According to a second aspect of the invention, there is provided apparatus for use in a method embodying the first aspect, the apparatus comprising a first pair of rolls supported for rotation about respective axes which are mutually inclined when the apparatus is used, means for varying the mutual inclination of the rolls during use and means for driving at least one of the rolls.

The apparatus preferably comprises first and second pairs of rolls and means for driving each pair of rolls whilst the rolls of the other pair remain in a drivable relative with other parts of the apparatus. Either one or both rolls of each pair may be driven directly. It will be understood that, in a case where only one roll of a pair is driven directly, the other roll will be driven indirectly during use of the rolls, for example by contact with a moving component which is being worked.

An example of a method embodying the invention and of apparatus embodying the invention will now be described, with reference to the accompanying drawings, wherein: FIGURE 1 shows a side elevation of the apparatus, FIGURE 2 shows diagrammatically and on an enlarged scale a first pair of rolls of the apparatus, together with adjacent parts, FIGURE 3 is a view similar to Figure 2 representing a second pair of rolls of the apparatus and FIGURE 4 is a perspective view of the apparatus and an assembly which is being worked by the second pair of rolls of the apparatus.

The apparatus illustrated in the accompanying drawings comprises hollow body 10 incorporating a base which rests on a floor, when the apparatus is in use. The body supports first and second pairs of rolls which are spaced apart horizontally, both lie near to the top of the body and both of which are spaced from both ends of the body. By the ends of the body, we mean those extremities of the body which are spaced apart in the same direction as the first pair of rolls is spaced from the second pair of rolls. Each of the rolls is rotatable relative to the body about a respective axis which extends generally upwardly and downwardly.

The apparatus further comprises a table 11 which is supported on the body 10 for adjustment relative thereto at least upwards and downwards in the vicinity of the first pair of rolls. The table may pivot about a horizontal axis remote from the rolls. The table has an horizontal, upwardly facing surface which is exposed at the upper side of the body and two stabilisers 12, 13 extend upwards from the table. The stabilisers are spaced from each other in a direction transverse to the length of the body and lie nearer to one end of the body than do at least all but one of the rolls of the first and second pairs. The stabilisers may be adjustable relative to the body both vertically and horizontally.

The rolls of the first pair are identified by the reference numerals 14 and 15. The roll 14 has at its periphery a step between a larger diameter portion 16 and a smaller diameter portion 17 which extends upwards from the larger diameter portion. The axis of rotation of the roll 14 is identified by the reference numeral 18.

Provision is made for relative adjustment of the table 11 and roll 14 in a direction along the axis 18. The permitted range of adjustment extends at least from a position in which the upper surface of the table 11 is level with the step between the portions 16 and 17 of the roll to a position in which the table lies substantially below the roll 14. Conveniently, the table 11 is adjustable upwardly and downwardly on the body 10 and the roll 14 is supported in a fixed position with respect to the body 10. Known means, for example screws, are provided for holding the table 11 in the position to which it has been adjusted.

The roll 14 is mounted in a fixed position on a respective shaft 19 which is supported in a fixed position by the body 10. The roll 15 is mounted on a respective shaft 20 for adjustment along the shaft. For adjusting the position of the roll 20 along its shaft and holding the roll releasably in a selected position, there is provided a screw and nut mechanism 21. By means of this mechanism, the roll 15 can be adjusted upwardly and downwardly relative to the body 10 and relative to the roll 14.

The shaft 20 and the roll 15 are supported by the body 10 for tilting relative to the body about an horizontal tilt axis 22 which is spaced downwards from the roll 15 and from the top of the body 10. For tilting the shaft 20 about the axis 22 relative to the body, there is provided a pneumatic piston and cylinder unit 23. Air under pressure may be applied to the cylinder unit 23 from a manually operable pump or from an external source of supply, under the control of a manually operable valve or under the control of an automatically operated valve. Return springs (not shown) act between the body 10 and the shaft 20 to oppose the action of the pneumatic piston and cylinder unit 23 and to urge the shaft 20 towards a position in which it bears a predetermined angular relation to the shaft 19. This predetermined relation may be a mutually parallel relation or a mutually inclined relation.The inclination of the shaft 20 relative to the shaft 19 can be varied by means of the pneumatic unit 23 within a range of, for example, 50.

Drive means is provided for driving the rolls 14 and 15. In the example illustrated, the drive means includes a single, variable speed, electric motor 25 mounted in a fixed position on the body 10 and driving the shafts 19 and 20 through a gear-train which includes bevel gears and a pair of spur gears 26 and 27. The gears 26 and 27 are enmeshed with each other throughout the permitted range of angular movement of the shaft 20 relative to the shaft 19 but the degree of mesh varies during angular adjustment of the shaft 19. The speed of the motor 25 may be controlled manually or automatically.

The rolls of the second pair are identified by the reference numerals 28 and 29. The roll 28 is mounted on a carrier 30 via an annular thrust bearing 31 and a roller bearing 32. The roll 28 has a shaft 33 which extends through a central opening in the carrier 30. The roll 28 lies below the roll 29 and has a flat, annular, upwardly-facing surface 34 and a peripheral surface 35 which is perpendicular to the surface 34.

The upper roll 29 of the second pair of rolls is mounted on a carrier 36 for rotation relative thereto about an axis 37. The carrier 36 is tiltable relative to the body 10 and the roll 28 about a horizontal axis 38 which extends transversely of the body 10 and is perpendicular to the axis 37. The axis 38 lies above, but close to, the surface 34 of the lower roll and near to the peripheral surface 35. The axis 38 is substantially a tangent to the surface 41 of the roll 29.

A pneumatic piston and cylinder unit 39 is provided for tilting the carrier 36 relative to the body 10 about the axis 38. Air may be supplied under pressure to the unit 39 from a manually actuated pump, a remote source of air under pressure via a manually operated valve or from a remote source via an automatically operated valve. Return springs act between the carrier 36 and the body 10 to oppose the action of the unit 39 and return the carrier to a lower position (not represented in the drawing).

The roll 29 has a downwardly-facing, annular, flat face 40 which, when the roll 29 is in its lower position, rests on the surface 34 of the roll 28. When the roll 29 is in its lower position, its axis 37 coincides with the axis about which the roll 28 rotates relative to its carrier 30. By means of the piston and cylinder unit 39, the carrier 36 and the roll 29 can be tilted upwards from the lowered position through an angle within the range 150 to 300 to the raised position represented in Figure 3. At the periphery of the annular face 40, the roll 29 has a peripheral face 41 which is frusto-conical. The apex angle defined by this frusto-conical face is the compliment of twice the angle through which the carrier 36 is tilted between the lowered and raised positions.The surface 41 extends radially outwards past the axis 38 to a position spaced from the axis of the roll 28 by a distance substantially equal to the radius of the peripheral surface 35 of the roll 28.

Adjacent to the frusto-conical surface 41 of the roll 29 at the periphery of the roll, there is a further frusto-conical surface 42 which intersects the surface 41 at a right angle. As shown in Figure 3, at one position around the axis 37, a portion of the surface 42 is substantially a continuation of the peripheral surface 35 of the roll 28. This position is turned during the working position.

The apparatus further comprises a guide roller 43 mounted on an arm 44 for rotation relative thereto about an axis 45. The guide roller has a cylindrical, peripheral surface which is parallel to the axis 45 and which lies immediately adjacent to the working position defined by the rolls 28 and 29. The arm 45 is mounted on the body 10 for pivoting relative thereto about a horizontal axis 46 which is adjacent to the base of the body and is spaced relatively far from the working position. By rocking of the arm 44 about the axis 46 relative to the body, the guide roller 43 can be moved towards and away from the rolls 28 and 29 at the working position. The arm 44 is one arm of a lever comprising a second arm 47 which is adjacent to the base of the body. A pneumatic piston and cylinder unit 48 acts between the body and the arm 47 to rock the lever about its axis 46.The piston and cylinder unit 48 is preferably supplied with air under pressure from a remote source via a manually controlled valve incorporated in the apparatus.

Drive means is provided for driving the rollers 28 and 29 of the second pair. The drive means comprises a variable-speed, electric motor 49 mounted in the body 10 and connected with the shaft 33 via a gear-train. Thus, the lower roll 28 is driven directly by the motor 49. The upper roll 29 is driven indirectly by the motor 49. When the upper roll is in its lower position, friction between the rolls 28 and 29 drives the roll 29 with the roll 28. When material is being worked by the rolls 28 and 29, as hereinafter described, and the roll 29 is tilted towards its raised position, the work is driven by friction between the work and the roll 28 and the friction between the work and the roll 29 drives the roll 29. Friction between the work and the guide roller 43 drives the guide roller.

In preparation for use of the apparatus in the joining of first and second tubular components, the table 11 is set at a level below the step between the smaller diameter portion 17 and the larger diameter portion 16 of the stepped roll 14. The roll 15 is retracted from the roll 14. The tubular component is placed with one end resting on the table 11, the roll 14 being inside the component and the roll 15 being outside the component. The stabilisers 12 and 13 also lie inside the tubular component and may engage the wall of that component.

The rolls 14 and 15 are driven by the motor 25 and the roll 15 is then tilted towards the roll 14 into engagement with the external surface of the tubular component. The tubular component is driven against the larger diameter portion 16 of the roll 14 and is then deformed over the step of the roll 14 as the roll 15 is tilted further towards the roll 14. Eventually, the tubular component is nipped firmly between the roll 15 and the smaller diameter portion 17 of the roll 14 and also between the larger diameter portion 16 and the roll 15, by which stage a joggle has been formed on the tubular component.

For forming a radially outwardly projecting flange on the other tubular component, this other component is worked by the rolls 14 and 15. However, in preparation for this working, the table 11 is raised to a position in which it is level with the step of the roll 14 and the height of the roll 15 above the table is adjusted. The second tubular component is placed on the apparatus with an end of the component resting on the table 11 and the motor 25 is used to drive the rolls 14 and 15. The roll 15 is tilted towards the roll 14 into engagement with the second component and the component is worked by the rolls 14 and 15 until it is nipped firmly between the roll 15 and the smaller diameter portion 17 of the roll 14. The second component then has a single, radially projecting flange.

The second component is removed from the apparatus and assembled with the first component so that the flange of the second component is received in the joggle of the first component. To prevent the components being inadvertently separated from each other, the joggle of the first component may be deformed slightly at a few positions around the component to retain the flange of the second component in assembled relation with the joggle. The assembly is then placed on the apparatus with the joggle of the first component received in the tapered gap between the frusto-conical surface 41 of the roll 29 and the flat surface 34 of the roll 28. It will be understood that the roll 29 is in its lowered position when the assembly of first and second tubular components is introduced into the apparatus.The guide roller 43 is then moved by the piston and cylinder unit 48 towards the rolls 28 and 29 to maintain the assembly in the required position relative to the rolls 28 and 29.

Further support for the assembly is provided by adjustable idler rolls 50 and 51. Respective mounts for the idler rolls are slidably carried on respective arms of the body 10. The idler rolls can be positioned in engagement with a lower edge of the assembly.

After the joggle of the first component, containing the flange of the second component, has been introduced into the gap between the rolls 28 and 29, driving of the roll 28 is commenced and tilting of the upper roll 29 is commenced.

Since the guide roller 43 holds the assembly against the lower roll 28, the assembly turns and imparts motion to both the guide roll and the upper roll 29.

The joggle is worked by the rolls 28 and 29 and is progressively bent around the flange of the second component to form a two leaf flange from the joggle with the flange of the second component trapped between these two leaves.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A method of joining end to end first and second tubular components wherein there is formed on the first component at one end thereof by bending a radially outwardly projecting first flange, there is formed on the second component at one end thereof by bending a radially outwardly projecting joggle, the flange is seated in the joggle to form an assembly comprising the first and second components and the joggle is bent around the flange to trap the flange between the leaves of a two-leaf flange formed from the joggle, characterised in that at least one of the assembly and the components is worked between a pair of rolls which rotate about respective, mutually inclined axes and in that the inclination of the axis of one roll relative to the axis of the other roll is varied during working.

2. A method according to Claim 1 wherein the first flange and the joggle are formed in succession by the same pair of rolls working the first component and the second component respectively.

3. A method according to Claim 2 wherein the position of one of the rolls relative to the other is adjusted along its axis between working the first component and working the second component.

4. A method according to Claim 2 or Claim 3 wherein the assembly is worked by a second pair of rolls whilst the first pair of rolls remains in a driveable relation with a driving motor for the first pair of rolls.

5. A method according to Claim 4 wherein, during working of the assembly, the axis of one roll of the second pair is tilted relative to the axis of the other roll of the second pair.

6. A method according to Claim 5 wherein the axis of one roll is tilted through an angle in excess of 150 relative to the axis of the other roll.

7. Apparatus for use in a method according to any preceding claim and comprising a first pair of rolls supported for rotation about respective axes which are mutually inclined when the apparatus is used, means for varying the mutual inclination of the rolls during use and means for driving at least one of the rolls.

8. Apparatus according to Claim 7 wherein the angular movement of the axis of one roll of the first pair relative to the axis of the other roll of the first pair is limited to a range of less than 100.

9. Apparatus according to Claim 7 further comprising a second pair of rolls supported for rotation about respective axes which are mutually inclined when the apparatus is used, means for varying the mutual inclination of the rolls of the second pair during use and means for driving at least one of the rolls of the second pair, wherein the range of permitted relative angular movement of the axes of the rolls of the second pair is in excess of 200.

10. Apparatus according to Claim 7 wherein one of the rolls has a frustoconical surface adjacent to a periphery of the roll and wherein the rolls are supported for relative tilting of their axes about a tilt axis which is a tangent to or is substantially a tangent to the frusto-conical surface.

11. Apparatus substantially as herein described with reference to and as shown in the accompanying drawings.