GB2105231A - Edge dressing strip steel - Google Patents

Abstract

A method of dressing the edges of narrow band strip steel slit from wide- band, in which the narrow strip comprises drawing the strip 1 through a roller unit having co-operating pairs of both surface rolls 2, 3 and edge rolls 4, 5 and in which cutting tools 8, 9 engage the strip edges between said sets of rolls to machine the edges and impart a desired contour thereto. Steadying rolls 13, 15 may be provided to reduce 'chatter' during the machining operation. <IMAGE>

Description

SPECIFICATION Edge dressing strip steel This invention relates to a method of, and apparatus for, dressing the edges of narrow strip steel which has been slit from wide-band material.

So called narrow strip steel is fabricated and used in the manufacture of many items but such manufacturing processes frequently require the strip to have been subjected to a minimum degree of cold working, particularly the strip edges, since the work hardening which can result from this may cause the steel to crack in these areas on subsequent processing. One particular example of this is in the manufacture of wheel rims for motorcars where cracks can be manifested during the forming and welding steps performed on low carbon steel narrow strip which has suffered work hardening at the edges.

Such work hardening can result for example from the slitting action itself, or more particularly, from the edge rectification processes performed on the slit edge to provide an acceptable edge surface free from burrs. It is for this reason that mill rolled narrow strip of the appropriate width required is preferred because the edges are naturally 'rounded' and have not been subjected to any additional 'work'. Hot rolling narrow strip to the appropriate width described in each instance is however a much more expensive process route than slitting wide band coil and it is an object of this invention to utilise this latter route and to dress the edges in such a manner as to avoid work hardening.

From one aspect, the present invention provides a method of dressing the edges of narrow band strip steel slit from wide-band, in which the narrow strip is drawn through a roller unit having co-operating pairs of both surface rolls and edge rolls, and in which cutting tools engage the strip edges between said sets of rolls minimally to machine the edges and impart a desired shape thereto.

The shape imparted may conveniently simulate that which would be produced should the steel have been produced on a hot narrow strip mill, i.e. with rounded edges.

in accordance with this invention then, the desired edge contour is produced without the edges being worked to any material degree.

In orderthatthe invention may be fully understood, two embodiments thereofwill now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic side elevation of apparatus for performing the method of this invention; Figure 2 is a plan view of this apparatus, and Figures 3 and 4 are elevation and plan views of a modified form of the apparatus.

Referring now to Figures 1 and 2 in the drawings, narrow strip 1 which has been slit from a wide band coil of say 2mm thick low carbon steel passes between two sets of pinch rolls 2, 3 and intermediate edge rolls 4, 5 which serve simply to guide the stock, and thence to a set of rubber-faced support rolls 6 mounted on a cutter head 7. Disposed on this head on opposite sides of the strip are two pairs of carbidetipped cutters 8, 9 which are vertically movable in a slide towards and away from the edge of the strip to predetermined positions whereby the edge is machined to remove a minimal amountfromthesur- face to define a 'rounded' edge contour.The strip then passes between another pair of edge rolls 10 which are each adjustable to provide a minimal degree of pressure on the machined edges to smooth off any sharp edges and thence through a final set of pinch rolls 11.

The two sets of edge guide rolls 4, 5 are each adjustable from one side as also are the pinch rolls 2, 3 and 11, the object of the pinch rolls only being to provide sufficient traction force, indeed a total gauge reduction of less than 2% may be effected through this unit.

In Figures 3 and 4 an alternative form of design is depicted in which the co-operating sets of cutters are displaced from one another. This has been found to reduce the incidence of 'chatter' during the machining operation. In particularthe modified head 12 supports a pair of steadying rolls 13, mounted above the strip, together with a pair of cutters 14 disposed on the opposite edges of the strip to machine a semirounded contour, followed by a further pair of steadying rolls 15 mounted below the strip in this instance, together with a pair of cutters 16 which likewise minimally machine the edges of the strip to complete the rounded contour. The strip then passes through edge rolls 10 and pinch rolls 11 as before.

1. A method of dressing the edges of narrow band strip steel slit from wide-band, in which the narrrow strip is drawn through a roller unit having cooperating pairs of both surface rolls and edge rolls and in which cutting tools engage the strip edges between said sets of rolls minimally to machine the edges and impart a desired shape thereto.

2. A method according to Claim 1, in which the cutting tools are all mounted at a single station.

3. A method according to Claim 1, in which a first pair of cutting tools is mounted at opposite edges of the strip at one station and a second pair of cutting tools is similarly mounted at a different station.

4. A method according to any one of Claims 1 to 3, in which the shape machined on the edges is a rounded contour.

5. A method according to any one of Claims 1 to 4, in which resiliently surfaced steadying rolls are mounted adjacent each cutter and bear on the strip surface.

6. A method of dressing the edges of narrow band strip steel substantially as herein described with reference to the accompanying drawings.

7. Apparatus for performing a method according to any one of the preceding claims, substantially as herein described with reference to Figures 1 and 2 or Figures 3 and 4 of the accompanying drawings.

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

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Edge dressing strip steel This invention relates to a method of, and apparatus for, dressing the edges of narrow strip steel which has been slit from wide-band material. So called narrow strip steel is fabricated and used in the manufacture of many items but such manufacturing processes frequently require the strip to have been subjected to a minimum degree of cold working, particularly the strip edges, since the work hardening which can result from this may cause the steel to crack in these areas on subsequent processing. One particular example of this is in the manufacture of wheel rims for motorcars where cracks can be manifested during the forming and welding steps performed on low carbon steel narrow strip which has suffered work hardening at the edges. Such work hardening can result for example from the slitting action itself, or more particularly, from the edge rectification processes performed on the slit edge to provide an acceptable edge surface free from burrs. It is for this reason that mill rolled narrow strip of the appropriate width required is preferred because the edges are naturally 'rounded' and have not been subjected to any additional 'work'. Hot rolling narrow strip to the appropriate width described in each instance is however a much more expensive process route than slitting wide band coil and it is an object of this invention to utilise this latter route and to dress the edges in such a manner as to avoid work hardening. From one aspect, the present invention provides a method of dressing the edges of narrow band strip steel slit from wide-band, in which the narrow strip is drawn through a roller unit having co-operating pairs of both surface rolls and edge rolls, and in which cutting tools engage the strip edges between said sets of rolls minimally to machine the edges and impart a desired shape thereto. The shape imparted may conveniently simulate that which would be produced should the steel have been produced on a hot narrow strip mill, i.e. with rounded edges. in accordance with this invention then, the desired edge contour is produced without the edges being worked to any material degree. In orderthatthe invention may be fully understood, two embodiments thereofwill now be described with reference to the accompanying drawings, in which: Figure 1 is a schematic side elevation of apparatus for performing the method of this invention; Figure 2 is a plan view of this apparatus, and Figures 3 and 4 are elevation and plan views of a modified form of the apparatus. Referring now to Figures 1 and 2 in the drawings, narrow strip 1 which has been slit from a wide band coil of say 2mm thick low carbon steel passes between two sets of pinch rolls 2, 3 and intermediate edge rolls 4, 5 which serve simply to guide the stock, and thence to a set of rubber-faced support rolls 6 mounted on a cutter head 7. Disposed on this head on opposite sides of the strip are two pairs of carbidetipped cutters 8, 9 which are vertically movable in a slide towards and away from the edge of the strip to predetermined positions whereby the edge is machined to remove a minimal amountfromthesur- face to define a 'rounded' edge contour.The strip then passes between another pair of edge rolls 10 which are each adjustable to provide a minimal degree of pressure on the machined edges to smooth off any sharp edges and thence through a final set of pinch rolls 11. The two sets of edge guide rolls 4, 5 are each adjustable from one side as also are the pinch rolls 2, 3 and 11, the object of the pinch rolls only being to provide sufficient traction force, indeed a total gauge reduction of less than 2% may be effected through this unit. In Figures 3 and 4 an alternative form of design is depicted in which the co-operating sets of cutters are displaced from one another. This has been found to reduce the incidence of 'chatter' during the machining operation. In particularthe modified head 12 supports a pair of steadying rolls 13, mounted above the strip, together with a pair of cutters 14 disposed on the opposite edges of the strip to machine a semirounded contour, followed by a further pair of steadying rolls 15 mounted below the strip in this instance, together with a pair of cutters 16 which likewise minimally machine the edges of the strip to complete the rounded contour. The strip then passes through edge rolls 10 and pinch rolls 11 as before. CLAIMS

1. A method of dressing the edges of narrow band strip steel slit from wide-band, in which the narrrow strip is drawn through a roller unit having cooperating pairs of both surface rolls and edge rolls and in which cutting tools engage the strip edges between said sets of rolls minimally to machine the edges and impart a desired shape thereto.

2. A method according to Claim 1, in which the cutting tools are all mounted at a single station.

3. A method according to Claim 1, in which a first pair of cutting tools is mounted at opposite edges of the strip at one station and a second pair of cutting tools is similarly mounted at a different station.

4. A method according to any one of Claims 1 to 3, in which the shape machined on the edges is a rounded contour.

5. A method according to any one of Claims 1 to 4, in which resiliently surfaced steadying rolls are mounted adjacent each cutter and bear on the strip surface.

6. A method of dressing the edges of narrow band strip steel substantially as herein described with reference to the accompanying drawings.

7. Apparatus for performing a method according to any one of the preceding claims, substantially as herein described with reference to Figures 1 and 2 or Figures 3 and 4 of the accompanying drawings.