GB2314317A

GB2314317A - Coil edge protecting strip

Info

Publication number: GB2314317A
Application number: GB9612779A
Authority: GB
Inventors: Ronald Richard Webb
Original assignee: Individual
Current assignee: Individual
Priority date: 1996-06-19
Filing date: 1996-06-19
Publication date: 1997-12-24
Also published as: GB9612779D0

Abstract

A strip for protecting the edge of a coil of material comprises a rigid plastic angle with one leg 3 tapered, this leg being thinner at the outer edge 5 of the leg. A press tool form produces a regular, eg sinusoidal, form over the length of the leg and also over the full width of the leg. The press tool thus has more effect on the thinner part of the leg and thus causes the leg to reduce in length longitudinally more than it will on the thicker side of the leg. The result of pressing the form in this leg is that the leg forms a radius of curvature so that it can be wrapped around the outer edge of a metal coil. If desired both legs may be tapered and the angle between them other than 90{.

Description

A RIGID PLASTIC PROTECTIVE EDGING FOR METAL COILS A protective edging for large diameter coils of metal strip or sheet is well known. The protective edging is usually made of the same material as that being protected. For example a coil of strip steel will have its corners' protected with a right angled section made of steel. The section being rolled into a right angle from flat strip. One leg of the angle is formed into a sinuate form, this one leg of this angle thus being formed in to a radius of curvature. Metal when formed into a sinuate form where the form is made on the one leg of a right angled section, has the effect of reducing the effective length of the inwardly extending leg thus allowing the right angled shape to be formed around a radius. Non metallic materials such as rigid plastics do not follow the same characteristics as metal.

According to the present invention there is provided a rigid plastic angle having one leg tapered. This leg being thinner at the outer edge of the leg. A pressed form produces a sinusoidal form over the length of the extrusion and the sine wave form extends over the full width of the leg. This pressed sinusoidal form provides sufficient flexibility to enable the rigid plastic angle to be formed around the external corner of a coil of metal strip.

A press tool which produces a sinusoidal form on the one leg of a uniform thickness of a plastic angle, does not have the effect of reducing the length of the outer edge of the inwardly extending leg so that the angled section can be formed around a given radius. The sinuate form produced in the leg of uniform thickness therefore does not form a radius of curvature in the leg.

Metal does not have the same memory as plastic and once formed or pressed into a shape, retains that shape and in retaining the shape encourages the inwardly extending leg to form into its natural radius of curvature. In carrying out this operation with an equivalent plastic shape of uniform thickness the sinuate form produced on the inwardly extending leg relaxes and therefore does not naturally produce an annular form where the inwardly extending leg develops a radius of curvature.

In this present invention there is provided a tapered inwardly extending leg where the thin part of the inwardly extending leg is the outer edge of the leg. When carrying out the same pressing operation on the tapered leg, it ends up having the same characteristics as that produced by the metal. The sinuate form that is produced by the press tool ensures that the thin edge of the inwardly extending leg has a more pronounced effect on this part of the inwardly extending leg thus encouraging this inwardly extending leg to form a radius of curvature smaller than the thicker part of the leg. A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows the two views of the coil of strip or sheet with the protective corners in position.

Figure 2 shows the right angle profile with the one leg tapered.

Figure 3 shows the sinuate form as pressed into the tapered leg.

Figure 4 shows the effect of the sinuate form on the tapered leg.

Figure 5 shows an end view of the metal coil with the protective edging in position.

Referring to the drawing of the coiled strip in figure 1, it can be seen that the protective corner section 1. shows the tapered part of the section, ie the inwardly extending tapered leg 3, pointing inwards towards the centre of the metal coil. The tapered inwardly extending leg is formed with the sinuate form which allows the right angled section to be formed around the radius of curvature of the external form of the metal coil. The protective edge 2 as shown in figure 1 that fits around the inside diameter of the metal coil does not require the same treatment since the section can be formed around this radius in view of the fact that the leg is not extending inwardly but extending outwardly. It is not necessary in this instance to use the same design of tapered leg. This section is shown as item 2 in figure 1. Referring to figure 2, the tapered leg is shown as 3 and the leg of constant thickness is shown as 4 and the actual profile is shown as 1.

Figure 3 shows an elevation and a plan view of the angle section 1 where the tapered leg has been formed into the sinuate form.

The effect of pressing the tapered leg is shown by the result in the plan view of figure 3. It can be seen that the sinuate form results in producing a radius of curvature as shown by line 7.

The line 8 follows the radius of curvature of line 7. The leg 4 is at a right angle to leg 3.

Figure 4 shows the cross section 1. The effect produced by pressing the sinusoidal form into the tapered leg 3 can be clearly seen. At the thin end of leg 3 the sinusoidal form has a high amplitude 5 and at the thicker end of the leg the sinusoidal effect has a low amplitude 6. This characteristic ensures that the leg 3 forms a radius of curvature so that the pressed protective edge forms around the outside diameter of the coil of metal strip. Without the taper in this leg 3, the pressed form would not have the effect of producing a radius of curvature. The memory in plastics allows the sinusoidal form to relax over the full width of the leg 3 and the angle section remains in a general straight line.

Claims

1. A rigid plastic angle having one leg tapered. This leg being thinner at the outer edge of the leg. A pressed form produces a sinusoidal form over the length of the extrusion, and the sine wave form extends over the full width of the leg. This pressed sinusoidal form provides sufficient flexibility to enable the rigid plastic angle to be formed around the external corner of a coil of metal strip.

2. A rigid plastic angle as claimed in claim 1 wherein a pressed design of sinusoidal form has the ability to be flexible enough to deal with coils of material of different radii.

3. A rigid plastic angle where the tapered leg can be of a different width and of different tapered angles as claimed in claim 1 and claim 2.

4. A rigid plastic angle as claimed in claim 1 and claim 2 where both legs are tapered.

5. A rigid plastic angle as claimed in claim 1 and claim 2 where the plastic is softer than the British Standard softness 0.

6. A rigid plastic angle as claimed in claim 1 and claim 2 where the angles of the leg are greater than 90 degrees.

7. A rigid plastic angle as claimed in claim 1 and claim 2 wherein the angles of the legs are less than 90 degrees.

8. A rigid plastic angle as claimed in claim 1 and claim 2 where the sinusoidal form is pressed over only part of the width of the tapered leg.

9. A rigid plastic angle substantially as described herein with reference to figures 1 to 5 of the accompanying drawing.

10. A rigid plastic angle claimed in claim 1 and claim 2 where the pressed form is of a regular form other than a sinusoidal form.