GB2212424A

GB2212424A - Bending elongate metal workpieces

Info

Publication number: GB2212424A
Application number: GB8826980A
Authority: GB
Inventors: John David Smith; William Gentleman
Original assignee: BOLIVAR STAMPING Ltd
Current assignee: BOLIVAR STAMPING Ltd
Priority date: 1987-11-19
Filing date: 1988-11-18
Publication date: 1989-07-26
Anticipated expiration: 2008-11-18
Also published as: GB2212424B; GB8727108D0; GB8826980D0

Abstract

A non-end portion of the workpiece is held against a support surface or pair of surfaces 3, a first pair of contact members e.g. rolls 5 are engaged against the workpiece on the same side and spaced from the support surface(s) and a second set of contact members e.g. rolls 7 are urged against the workpiece on the opposite side and between the support surface(s) 3 and the first set of contact members 5 to bend the workpiece. Further outer rolls 9 bend the outer workpiece ends against surfaces 11. <IMAGE>

Description

THE SHAPING OF ELONGATE METAL WORKPIECES This invention relates to a method of, and apparatus for, shaping elongate metal workpieces to provide a plurality of bends therein.

It is an object of the present invention to provide a method of, and apparatus for producing a multiple bend article from an elongate workpiece.

According to a first aspect of the present invention a method of shaping an elongate metal workpiece comprises the steps of holding a non-end portion of the workpiece against a support surface or spaced apart support surfaces; engaging a first pair of contact members against the workpiece on the same side as the support surface (s) and at respective positions outwardly of the support surface (s) and urging a second pair of contact members against the workpiece on the opposite side to the first pair of contact members at respective regions between the first pair of contact members and said support surface (s) to bend the workpiece at these regions.

At the regions on the workpiece where the second pair of contact members are urged against them, the workpiece is bent out of its original form.

Conveniently the second pair of contact members are moved in a first direction to bend the workpiece relative to the support surface (s) and the first pair of contact members are moved in the direction opposite to the first direction to bend the workpiece relative to the second pair of contact members.

Preferably each end portion of the elongate workpiece is bent out of alignment from the non end portion which is held against the support surface (s).

The end portions may be bent out of alignment prior to the workpiece being bent at the regions between the first pair of contact members and the support surface (s).

According to a second aspect of the invention, a machine for shaping an elongate metal workpiece comprises a member providing a support surface or a pair of spaced apart members each of which provide a support surface for a workpiece; means for holding a non-end portion of the workpiece against the support surface (s); a first pair of contact members engageable with the workpiece on the same side as the support surface (s) and at respective positions outwardly of the support surface (s) and a second pair of contact members engageable with the workpiece on the opposite side to the first pair of contact members and at respective regions between the first pair of contact members and said support surface (5).

The contact members are conveniently in the form of rollers having a concave peripheral surface which are urged against the workpiece by fluid operated pistoncylinder devices.

In order that the invention may be more -readily understood, it will now be described, by way of example only, with reference to the accompanying drawings in which: Figures 1-3 show successive steps in the method of shaping an elongate metal workpiece in accordance with one embodiment of the present invention; and Figures 4-7 show successive steps in the method of shaping an elongate workpiece in accordance with an alternative embodiment of the invention.

Referring to Figures 1-3, the elongate metal workpiece which is to shaped is indicated by reference numeral 1. A first pair of spaced apart rollers 3 are rotatable about fixed axes. These rollers constitute support surfaces against which the workpiece can be held by one or more rams 4.

Outwardly of each fixed roller 3 and on the same side of the workpiece as the rollers 3, there is a roller 5 which together constitute a first pair of contact member. On the opposite side of the workpiece 1 to the rollers 3 and 5 there are a pair of rollers 7 which constitute a second pair of contact members. The rollers of the second pair are outwardly of the rollers 3 and inwardly of the rollers 5. The rollers 7 are mounted on rams (not shown) which enable the rollers to be forced into the regions between the rollers 3 and 5.

Outwardly of the rollers 5 there are positioned a pair of rollers 9 which constitute a third pair of rollers. These rollers are on the same side of the workpiece as the rollers 5. A stop 10 is provided outwardly of one of the rollers 9 and a pair of fixed blocks 11 are positioned almost in line with the rollers 5 but on the opposite side of the workpiece to the rollers 5.

To shape the workpiece 1 it is first supported on all the rollers 3, 5 and 9 with one end of the workpiece abutting stop 10. The ram 4 is engaged so that it holds the workpiece against the support surfaces provided by the rollers 3, Figure 1. The rollers 7 are then urged together against the workpiece at the regions outwardly of the portion held against the rollers 3 in order to force parts of the workpiece between the pairs of rollers 3, 5 as shown in Figure 2. This action forms bends around the rollers 3 and around the rollers 7. The ends of the workpiece are splayed outwardly as shown in Figure 2. The degree of bending applied to the workpiece depends upon the extent of the displacement of the rollers 7 and the position of the rollers 7 with respect to the rollers 3 and 5.

The rollers 9 are then displaced outwardly by rams (not shown) so as to force the ends of the workpiece against the fixed blocks 11 and thus the action of the rollers 9 and the fixed blocks 11 bend the end portions out of alignment with the portions adjacent thereto and so that the end portions are in planes which are substantially at right angles to the portion of the workpiece which is held against the rollers 3. The rollers 7 and 9 are then returned to their original positions and the ram 4 is removed from the workpiece.

The workpiece is then of generally U-shaped form as shown in Figure 3.

In an alternative embodiment of the invention shown in Figures 4 to 7, the pairs of rolls 3, 5 and 7 are as shown in Figures 1 to 3 and the rollers 9 are replaced by rollers 13 and between each pair of rollers 5 and 13 and on the opposite side of the workpiece thereto there is a rigid rod 12.

To shape the workpiece 1 it is held against the pairs of rollers 3, 5 and 13 by the ram 4. The rods 12 are then slid into their positions where they overlie the workpiece. The rollers 13 are then forced against the workpiece and because the rods 12 are off-set slightly from the adjacent edge of the rollers 13, sheer forces are applied to the workpiece to cause the end portions of the workpiece to be inclined upwardly with respect to the remaining portion of the workpiece. This position is shown in Figure 5. The rods 12 are then slid away from the workpiece. Rollers 7 are then urged together against the workpiece at regions outwardly of the portion held against the support surfaces provided by the rollers 3 in order to force parts of the workpiece between the pairs of rollers 3 and 5 leaving the pre-shaped ends of the workpiece splayed outwardly. The degree of bending applied to the workpiece depends upon the displacement of the rollers 7 and the position of the rollers with respect to the rollers 3 and 5. The rollers 5 are then firmly urged against the workpiece so as to force the ends of the workpiece outwardly of the rollers and thus form additional bends on the workpiece. The rollers 5 are displaced sufficiently for the end portions of the workpiece to be bent into planes which are substantially at right angles to the portion of the workpiece which is between the rollers 3 as shown in Figure 7. A limit switch 14 is conveniently provided so that when it is actuated by an end portion of the workpiece the rollers 5 and 7 are returned to their original positions and the ram 4 is removed from the workpiece. The workpiece is then of generally U-shaped form as shown in Figure 7.

In both embodiments of the invention the workpiece 1 can be of any convenient cross-section, but it is usually either of cylindrical tubular form in which case the rollers have concave peripheral surfaces or it can be of channel cross-section in which case the rollers have slots in their outer peripheral surface to accommodate the parallel limbs of the channel section.

Clearly the two rollers 3 can be replaced by a single member which provides the support surface against which the non-end portion of the workpiece is held by the ram 4.

The machine may be arranged so that a plurality of workpieces 1 are held in side-by-side relation against the supports 3 by the ram 4 and all the workpieces are shaped simultaneously by the methods of operation described above.

Claims

1. A method of shaping an elongate metal workpiece comprising the steps of holding a non-end portion of the workpiece against a support surface or a pair of spaced apart support surfaces; engaging a first pair of contact members against the workpiece on the same side as the support surface (s) and at respective positions outwardly of the support surface (s) and urging a second pair of contact members against the workpiece on the opposite side of the first pair of contact members at respective regions between the first pair of contact members and said support surface (s) to bend the workpiece at these regions.

2. A method as claimed in claim 1, in which the second pair of contact members are moved in a first direction to bend the workpiece relative to the support surface (s) and the first pair of contact members are moved in the direction opposite to the first direction to bend the workpiece relative to the second pair of contact members.

3. A method as claimed in claim 1 or 2, in which each end portion of the elongate workpiece is bent out of alignment from the non-end portion which is held against the support surface (s).

4. A method as claimed in claim 3, in which the end portions are bent out of alignment prior to the workpiece being bent at the regions between the first pair of contact members and the support surface (s).

5. A method as claimed in claim 3, in which the end portions are bent out of alignment by third and fourth pairs of contact members which engage opposite sides of the workpiece.

6. A method as claimed in claim 3, in which the end portions are bent out of alignment after the workpiece has been bent at the portions between the first pair of contact members and the support surface (s).

7. A method of shaping an elongate metal workpiece substantially as hereinbefore described with reference to the accompanying drawings.

8. A machine for shaping an elongate metal workpiece comprising: a member providing a support surface or a pair of spaced apart members each of which provides a support surface for a workpiece; means for holding a non-end portion of the workpiece against the support surface (s); a first pair of contact members engageable with the workpiece on the same side as the support surface (s) and at respective positions outwardly of the support surface (s); and a second pair of contact members engageable with the workpiece on the opposite side of the first pair of contact members and at respective regions between the first pair of contact members and said support surface cos).

9. A machine as claimed in claim 8 including means for bending the end portions of the workpiece out of alignment with the part of the workpiece held against the support surface (s).

10. A machine as claimed in claim 9 in which the means for bending the end portions of the workpiece comprise a third pair of contact members engageable with the workpiece on the same side as the first set of contact members and outwardly thereof and a fourth pair of contact members engageable with the workpiece on the same side as the second pair of contact members and at respective positions between the first and third sets of contact members.

11. A machine for shaping an elongate metal workpiece substantially as hereinbefore described with reference to the accompanying drawings.

12. A machine as claimed in claim 8, 9, 10 and 11 in which a plurality of elongate metal workpieces can be shaped simultaneously.