GB2258286A

GB2258286A - Forming bends in a planar tube array

Info

Publication number: GB2258286A
Application number: GB9116590A
Authority: GB
Inventors: Anthony Alan Fitzgerald
Original assignee: Ford Motor Co
Current assignee: Ford Motor Co
Priority date: 1991-08-01
Filing date: 1991-08-01
Publication date: 1993-02-03
Also published as: GB9116590D0

Abstract

A process for forming bends in a planar array of tubes (1, 2 and 3) linked together by webs (4 and 5) including the step of removing the web over a section (6) of the array where the change in orientation and/or direction is required, and forming the bend, for example by a heat forming process. Preformed arrays of tubes are particularly useful in the automotive industry. The webs may be defined by an outer cover. <IMAGE>

Description

FORMING BENDS IN A PLANAR TUBE ARRAY The invention relates to a process for forming bends in a planar array of tubes which are linked together by webs between adjacent tubes. It is known to extrude a number of parallel tubes linked by webs. Japanese patent 57/53,328 shows a known way of forming bends in webbed tubing. However, such a method requires the total removal of the web and cannot be easily adapted for shaping webbed tube so that it changes direction for example by 90 in either orientation or in the same plane.

The present invention seeks to overcome such problems without unduly weakening or stressing the tubing. It will be appreciated that if multiple planar tubing which has been extruded as a linear array is required to be formed through 904 whilst retaining the same plane on entry and exit of the bend, then the outside tube will be considerably stretched and possibly unduly narrowed and weakened by the substantially longer path traversed by the outer tube compared with the inner tubes.

THE INVENTION According to the present invention there is provided a process for forming bends in a planar array of tubes linked together by webs between adjacent tubes, said process comprising forming the array into a predetermined shape by first interrupting the web between adjacent tubes over a first section of the array and deforming the orientation and/or, direction of the tubes within the first section so that the web does not constrain the spatial relationship of the tubes within said first section.

References herein to interrupting of the web include not only the cutting and physical removal of the whole or part of the web over an area between adjacent tubes, but also include the interruption of the integrity of the web by slitting it along its length without removing any material.

The tubes may be formed by extrusion of a thermoplastics material to produce the planar array of tubes joined by webs.

The webs may be interrupted subsequently over predetermined sections by means of cutting blades, a laser cutter or any other cutting means.

Preferably the process comprises two steps after the web has been cut. The array of tubes is twisted in one step about an axis generally parallel to the length of the tubes and then the array is bent out of the original plane of the tubes to form a compound angle between the array on one side of the first section and the array on the opposite side.

The tubes may be of the same or differing sizes, and the sequence of tubes in the array at one end of the first section may be maintained or interchanged relative to the other end of the section during the forming process.

The invention also relates to tubes formed according to the invention.

The invention will now be described by way of example, with reference to the accompanying drawings in which: Figure 1 shows in plan and in section an array of tubes linked by adjacent webs; Figure 2 shows the array of Figure 1 after formation of a 90e bend; Figure 3 shows the array of Figure 2, viewed in the direction of arrow A; and Figure 4 is a view corresponding to Figure 3, but showing the array turned through 180' relative to the array shown in Figure 3.

REFERRING NOW TO THE DRAWINGS; Figure 1 shows in plan and cross section a planar tube array consisting of three tubes, 1, 2 and 3 interlinked by webs 4 and 5 formed during the extrusion process. After the extrusion process parts of the web over sections 6 and 7 are removed by means of cutting blades or similar suitable web removal means such as laser cutters.

Referring now also to Figure 2 the tube array is shaped around a former [not shown] to form a first bend by twisting the tube array in an nati-clockwise direction through 90' over section 6 at the approach to the former. The array is wrapped around the former to form a second so bend and at section 7 as it leaves contact with the former a third bend is made by twisting in a clockwise direction through 90 to its original plane of orientation. It will be seen that as the web is cut away from sections 6 and 7 on figure 2 that the tubes are not constrained by the position of adjacent tubes over these sections.This permits the tubes to be twisted more readily about the axis of the array (through 90") before - and after - being bent through 90 about an axis trnsverse to the array. The shaping process is a heat forming process well known for treating thermoplastics material.

Figure 3 shows the array of tubes rotated in direction through 90' whilst maintaining the same plane of orientation. As the web has been removed over the section 6 the tubes 1 and 3 will be laterally displaced to accommodate the change of direction as the array is rotated through 90'.

If necessary, and as shown in Figure 4 the order of the tubes may be reversed during the change of direction. This is achieved by making the first and third bends both in a clockwise or both in an anti-clockwise direction.

As mentioned earlier the tubes may be formed by an extrusion process or the array may be formed by a co-extruded jacket or cover surrounding a set of preformed individual tubes which are then held together by the co-extruded cover. It will be appreciated also that the tubes formed by the present invention are particularly useful in the automotive industry where it is a particular advantage to maintain a neat and orderly array of pipes for example, in the fuel supply system.

Claims

CLAIMS:

1. A process for forming bends in a planar array of tubes linked together by webs between adjacent tubes, said process comprising forming the array into a predetermined shape by first interrupting the web between adjacent tubes as a first section of the array, and deforming the orientation and/or direction of the tubes within the first section, so that the web does not constrain the spatial relationship of the tubes within said first section.

2. A process as claimed in Claim 1 in which the array of tubes is formed by an extrusion of thermoplastics material.

3. A process as claimed in Claim 2 in which the extrusion of thermoplastics material forms a cover over individual tubes.

4. A process as claimed in any preceding claim in which at least one of the tubes differs in size from other tubes in the array.

5. A process as claimed in any preceding claim in which the orientation and/or direction of the tubes is formed by a heating process.

6. A planar array of tubes made by a process as claimed in any preceding claim in which the plane of the array is rotated through a predetermined angle.

7. A planar array of tubes made by a process as claimed in any of the Claims 1 to 6 in which the plane of the array is maintained between entry and exit of the formed section.

8. A planar array of tubes as claimed in Claims 6 or 7 in which the sequence of tubes on entry to the formed section is interchanged during the change in orientation and/or direction.

9. A process for forming ends in a planar array of tubes linked together by webs between adjacent tubes substantially as herein before described with reference to the drawings.

10. A planar array of tubes linked together by webs between adjacent tubes substantially as herein before described with reference to the accompanying drawings.