US3793862A

US3793862A - Method and apparatus for continuously forming contoured metal strips

Info

Publication number: US3793862A
Application number: US00284699A
Authority: US
Inventors: W Eddy; F Richards; J Thompson
Original assignee: Phillips Petroleum Co
Current assignee: Huhtamaki Consumer Packaging Inc
Priority date: 1972-08-30
Filing date: 1972-08-30
Publication date: 1974-02-26
Anticipated expiration: 1991-02-26

Abstract

This invention resides in the method and apparatus for continuously forming contoured metal strips. In the invention a continuous metal strip package is maintained on a rotatable table, tension is placed on the continuous strip and the strip is fed from the strip package into a contouring zone at which location forces are exerted on the strip by at least one contouring roll set for continuously bending the strip to a preselected configuration. Forces are thereafter exerted on the contoured strip to straighten the strip to form a linear contoured continuous strip and indent said strip at preselected locations. The continuous, linear contoured strip is thereafter severed at preselected locations and assembled for further handling.

Description

United States Patent Eddy et al.

[ METHOD AND APPARATUS FOR CONTINUOUSLY FORMING CONTOURED METAL STRIPS Inventors: William R. Eddy; Frank P.

Richards; James K. Thompson, all r of Kansas City, Mo.

Assignee: Phillips Petroleum Company, Bartlesville, Okla.

Filed: Aug. 30, 1972 Appl. No.: 284,699

US. Cl 72/4, 72/12, 72/16, 72/203 Int. Cl B21d 55/00, B2lb l/OO Field of Search.. 72/4, 203, 365, 366, DIG. 11; 1 13/1 16 R Lawson 113/116 R 3,646,797 5/1972 Overway 72/326 Primary ExaminerCharles W. Lanham Assistant ExaminerRobert M. Rogers [5 7] ABSTRACT This invention resides in the method and apparatus for continuously forming contoured metal strips. In the invention a continuous metal strip package is maintained on a rotatable table, tension is placed on the continuous strip and the strip is fed from the strip package into a contouring zone at which location forces are exerted on the strip by at least one contouring roll set for continuously bending the strip to a preselected configuration. Forces are thereafter exerted on the contoured strip to straighten the strip to form a linear contoured continuous strip and indent said strip at preselected locations. The continuous, linear contoured strip is thereafter severed at preselected locations and assembled for further handling.

19 Claims, 9 Drawing Figures PAIENIEB FEBZ 6 I974 SHEET 1 [IF 5 1 METHOD AND APPARATUS FOR CONTINUOUSLY FORMING CONTOURED METAL STRIPS In order to prevent waste of time, labor, equipment, and space, it is desirable to providean apparatus that will continuously form linear, contoured metal strips from a continuous metal strip. These contoured strips are utilizable for reinforcing the edges of paperboard cartons, for example.

This invention therefore resides in the method and apparatus for continuously forming contoured metal strips. In the invention a'continuous metal strip package is maintained on a-rotatable table, tension is placed on the continuous strip and the strip is fed from the strip package into a contouring zone at which location forces are exerted on the strip by at least one contouring roll set for continuously bending the strip to a preselected configuration. Forces are thereafter exerted on the contoured strip to straighten the strip to form a linear contoured continuous strip and indent said strip at preselected locations. The continuous, linear contoured strip is thereafter severed at preselected locations and assembled for further handling.

Other aspects, objects, and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the drawings.

The drawings are diagrammatic views of the apparatus of this invention. FIGS. 1 and 2 show the apparatus of this invention, FIGS. 3 and 4 show the rotatable tables for continuous strippackages, FIG. '5 shows a brake mechanism for the table, FIGS. 6 7 and 8 show the contouring zone, straightening die, and flying cutter assembly, and FIG. 9 shows an electric control diagram.

Referring to FIGS. 1, 2, 3, and 4, a frame 2 is provided for maintaining the apparatus of this invention. The frame may be a unitary frame, separately con nected frames, or of any form which will maintain the various elements at their'respective locations. I

A strip unwind table 4 is rotatably mounted on the frame 2. In order to save time and labor during machine operations, it is preferred that a pair of strip unwind tables 4, 4 be mounted on the frame 2. By providing the pair of tables 4, 4' one table can be loaded with a metal strip package 6 during the running of the apparatus, thereby reducing shutdown time during mounting of a new package.

It is also preferred that a lift table 8 (FIG. 2) be provided adjacent the unwind tables 4, 4' for assisting in placing a strip package 6 on an unwind table 4.

The unwind table 4 is concentrically attached to a first shaft 10 for rotation of the table 4 preferably in a horizontal plane.'The first shaft has a brake pulley l2 fixedly mounted thereon and can have a shaft collar 14 mountedon the upper end of the shaft for receiving an end of a centering shaft 16. extending from a location higher in elevation than the top of the unwind table 4 and through an opening in the table 4.

A clamp wheel collar 18 is positioned about the centering shaft 16 at an elevation above the top of the table 4 and is movable along said shaft by means of wheel 88 for example. A plurality of centering shoes 20 are pivotally connected to the clamp wheel collar, by for example force rods 22, and are slidably attached to rods 90 projecting from hub 92 for synchronous, transverse wheel 88 and the clamp wheel collar 18 along the centering shaft 16.

A positioning and retaining hook 24 (FIG. 3) can be provided on the opposite sides of hub 92 for engaging spokes 94 extending from the shaft collar 14 to the table rim 96 to maintain the centering and clamping mechanism relative to the table during movement of the shoes into forcible contact with the walls of the strip package 6 for centering and attaching the strip package 6 relative to the unwind table 4. The centering shaft 16 and associated elements can be threaded for moving the'shoes and concentrically locking the package 6 onto the table. j

Referring to FIGS. 2 and 7, a metering roll set '26, comprising adjacent, cooperating

rolls

28, 28 forming a roll nip, is positioned adjacent the unwind table 4 for receiving the continuous metal strip 30 from the strip package 6 and delivering the strip for further processing" at a preselected rate. A power means 32 (FIGS. 2 and 8), such as a variable speed electric motor for example, is associated with the metering roll set 26 for the operation thereof.-

A contouring zone 33 having at least one contouring roll set 34 is positioned adjacent the metering roll set- 26 for receiving the continuous metal strip 30 in the nip of the roll sets, 34, 34, 34", and 34" for example, exerting forces on the metal stripand bending said strip to a preselected configuration defined by the configuration of the roll surfaces of the contouring roll sets.

Where a plurality of contouring rollsets are utilized, as

best seen in FIG. 2, each roll set 34, 34, 34", 34' can have surfaces and a nip' of different configuration for bending the strip 30 differently at each roll set. The contouring roll sets are driven by power means 32.

Referring to FIGS. 6, 7 and 8, a strip straightening die 36 has an opening 38 therethroughv for passing the formed continuous strip through the opening38 (FIG. 8). The die 36 is positioned adjacent the contouring zone and is movable relative to the lattermost contouring roll set nip which bends the strip 30, here roll set 34", for bending the contoured strip and forming a continuous, generally linear contoured strip. The die can be constructed by a plurality of threaded adjusting elements 40 for moving and maintaining said die 36 to and at preselected attitudes.

A set of cooperating

pinch rolls

42, 42' and 42" are positioned adjacent the die 36 for receiving the conselected locations along thecontinuous contoured radial movement of the shoes 20 relative to a hub 92 and the centering shaft 16 in response to movement of strip. It is preferred that-the pinch rolls be synchronously rotated for simultaneously indenting the strip from opposed sides with corresponding protrusions 44 of the opposed pinch rolls 42, 42'. In this construction, the need for protrusion backup is eliminated and the danger of linearly bending the strip is reduced. These indentions are important during stacking of the formed severed strips and feeding of said strips for attachment to a paperboard container. The pinch roll setis driven by power means 32.

A flying cutter 46 having a cutting element 48 is movable along the pathway of the continuous, linear, contoured strip and is actuatable for cutting said strip in two at preselected locations. The cutter element 48 is preferably associated with a cam 50 driven by power means 32 for actuating the cutter element 48 and severing the contoured strip in response to the flying cutter 46 contacting the cam thereby triggering the cutting element 48 to actuate and sever the metal strip at a preselected location along the pathway of the flying cutter and on the continuous contoured metal strip.

As shown in FIGS. 7 and 8, the flying cutter 46 is preferably connected by a crank rod 52 to one of the pinch rolls, 42 for example, for synchronously moving the flying cutter in response to the rotation of the pinch roll. lt is further preferred that the crank rod 52 be of a dimension and be connected to the pinch roll at a location at which the linear speed of the flying cutter 46 during actuation of the cutting element 48 is at least equal to the linear speed of the portion of the contoured strip being cut during the operation of the apparatus. More preferably, the cutter speed will be slightly faster than the contoured strip at the termination of the cut to drive the cut-off piece away from the contoured continuous strip.

It is preferred that a magnetic roll 54 (FIGS. 1 and 2) be positioned adjacent the flying cutter 46 for receiving the cut-off continuous strip, moving the cut-off strip to a preselected stacking location, and depositing the strip at the stacking location. The magnetic roll 54 is rotated to move the cut-off strip to the stacking location by a power means 19 such as an electric motor.

A conveyor 56 (FIG. 1 such as a conveyor belt for example, forms-a floor for the stacking location and is actuatable for moving the severed contoured strips from the stacking location in response to a received signal. A curvalinear guiding chute 57 can be positioned at the stacking location for receiving a cut-off strip and guiding it toward and onto the conveyor and can rotate said strip. This chute 57 is provided for reducing the weight exerted on the bottommost strips by the overlying strips thereby preventing said weight from deforming the strips.

That signal can be from an electric eye system 58 (FIG. 2) positioned a preselected elevation above the stacking location for delivering the signal to the conveyor 36 in response to the strips at the stacking location being at the elevation. A strip counter 49 (FIG. 9) can be associated with the movement of flying cutter 46 by means of switch47 (FlGS. 7 and 9) for delivering a signal to a solenoid carrying an offsetting stop plate 62 (FIG. 1) which can be inserted for positioning the severed contoured strips of one stack in a staggered configuration relative to the severed contoured strips of an adjacent stack for ease in handling.

Referring to FIGS. 2 and 5, a brake mechanism can be associated with the unwind table for terminating the rotation of said table in response to a received signal. In one embodiment, a belt 64, for example a V belt 64, can be caused to move into forcible engagement with a brake pulley 12 for terminating rotation. Here the belt 64 can pass about at least a portion of the belt pulley 12 of the strip unwind table with the belt having a first and second end 65 and 67 (FIG. 4) fixedly attached to the frame and a second central portion 66 (FIG. 3) being movable in response to the signal for moving the belt 64 into forcible contact with the brake pulley l2.

A lever arm 68 having an idle roll 70 rotatably connected thereto can be pivotally connected to the frame 2 and positioned at a location for moving the metal strip to a nonlinear position at a location between the table4 and the metering roll set 26.

A spring 72 or other biasing means can be attached to the lever arm 68 for urging the arm in an opposed direction relative to the force exerted on the arm 68 by the continuous metal strip 30 through the brake idle roll 70. In this construction, should the continuous strip break during operation, the spring 72 will move the lever arm 68 thereby moving the cable 74 connected to the belt 64 at 66 for actuating the table brake and terminating rotation of the table 4. The spring 72 or biasing means can be sized to permit applying of the brake at tensional forces below a preselected value.

A gaging roll 76 (FIGS. 2 and 7) can be positioned adjacent the first metering roll 28 and spaced therefrom by the intervening continuous metal strip 30 during the operation of the apparatus. A lever arm 78 (FIG. 7) is connected to the gaging roll 76 at a first end and is pivotally mounted relative to the first metering roll 28. Microswitches 31 and 86 are associated with the first end of the lever arm 78 and are operably connected to the power menas 32 terminating the rotation of the metering roll set 26 and contouring roll set 34 in response to movement of the second end of the lever arm greater than a preselected distance toward and from the metering roll set. The passage of continuous metal strips toward the metering roll set 26 that is under or over thickness will cause the operation of the apparatus to terminate.

Referring to FIG. 5, a hook arm 84 can be associated with the lever arm 68 and other apparatus for releasably locking the lever arm 68 at a location at which the brake is disengaged. This construction is desirable for placing the brake out of operation when making adjustments in the apparatus, starting up the operation or during various other conditions of operation, for exam- 15 is momentarily closed to lock in relay l7 and start magnetic wheel motor 19. Relay l7 closes switches2l and 23. Relay 17 will remain locked in until push button stop switch 25 is opened. The main drive motor 32 may now be started to run continuously by momentarily closing push button switch 29 if run out switch 31, which is closed when at-least one thickness of strip is present on the gaging roll, and, double strip switch 86 which opens if more than one thickness of strip is present on the gaging roll, are both closed, and, if cage door safety switches 35 and 37 are both closed (cages closed). Closing switch 29 actuates relay 39 closing switches 41, 43 and 45. Switch 41 locks in relay 39 and continues to feed main drive motor 32 when switch 29 is released. The main drive motor may be stopped and relay 39 unlocked by momentarily opening any one of

switches

11, 13, 31, 86, 35, 37, or 25 which would unlock relay l7 and open 23.

in the operation of the apparatus, a continuous metal strip package 6 is maintained on the rotatable table 4, a tension is placed on the continuous strip 30, and said strip is fed from the package 6. The continuous metal strip is passed through a contouring zone 33 at which location forces are exerted on .the strip by at least one contouring roll set 34 with said forces being ofa magnitude sufficient for continuously bending the continuous strip to a preselected configuration. Forces are thereafter exerted on the contoured strip for forming a generally linear, contoured continuous strip and indenting the contoured continuous strip at preselected locations along its length. The continuous contoured linear strip is then severed at preselected locations and the strips are assembled for further processing.

Other modifications and alterations of this invention will become apparent to those skilled in the art from the foregoing discussion and accompanying drawings, and it should be understood that this invention is not to be unduly limited thereto.

What is claimedis:

1. An apparatus for forming contoured metal strips from a packaged, continuous metal strip, comprising:

a frame;

a strip unwind table rotatably attached to the frame;

fixing means connected to the unwind table for maintaining a strip package fixedly centered and attached to said unwind table and rotatable there'- with;

a metering roll set positioned adjacent the unwind table for receiving the continuous metal strip and passing said strip at a preselected rate;

means for driving the metered roll set at the preselected rate;

a contouring zone having at least one contouring roll set positioned adjacent the metering roll set for receiving the continuous metal strip in the nip of the contouring roll set and bending said strip to a preselected configuration defined by the configuration of the roll surfaces of the contouring roll set;

a strip straightening die positioned adjacent the contouring zone, said die having an opening for passing the formed continuous strip therethrough and being movable relative to the contouring roll set nip for exerting forces thereon for bending the contoured strip and forming a continuous, generally linear, contoured strip;

a set of pinch rolls having protrusions on the surface thereof and being rotatable and positioned adjacent the die for receiving the contoured continuous strip in the nip of the said pinch rolls and indenting the contoured strip with the protrusions at preselected locations along said strips;

a flyingcutter having a cutting means and being movable along the pathway of the continuous, linear,

' contoured strip and actuatable for cutting 'said strip in two at reselected locations; and

means for assembling the severed contoured strips.

2. An apparatus, as set forth in claim 1, including a brake attached to the rotatable unwind table for terminating the rotation of said table in response to a received signal; and

.tension means associated with the continuous strip the tension means comprises a brake idle roll, a lever arm rotatably connected to the brake idle roll and pivotally connected to the frame and being at a location for moving the metal strip to a nonlinear position at a location between the table and the metering rolls;

a biasing means attached to the lever arm for urging the arm in an opposed direction relative to the force exerted on the arm by the metal strip through thebrake idle roll; and

means for attaching the central portion of the belt to the lever arm for urging the belt into forcible contact with the belt pulley in response to the force exerted on the brake idle roll being less than a preselected value.

4. An apparatus, as set forth in claim 3, including means for releasably locking the lever arm at a location at which the brake is disengaged.

5. An apparatus, as set forth in claim 1, including a gaging roll positioned adjacent a roll of the metering roll set and being spaced from said roll by the intervening metal strip during operation of the apparatus;

a lever arm rotatably connected to the gaging roll at a first end and being pivotally mounted relative to the metering roll; t microswitches associated with a firstend of the lever arm and being operably connected to the means for driving the metering roll set and adapted to terminate the rotation of the metering rolls in response to movement of the lever arm second end greater than a preselected distance from a preselected location. a

6. An apparatus, as set forth in claim 1, wherein the contouring zone has a plurality of contouring roll sets with the roll surfaces and nip of each set being of a different configuration than the surfaces and nips of the other roll sets for bending the strip differently at each roll set. t

7. An apparatus, as set .forth in claim 1, wherein the strip straightening die is contacted by a plurality of threaded adjustment elements for maintaining the die at preselected positions and moving said die.

8. An apparatus, as set forth in claim I, wherein each of the opposed pinch rolls has a pair of protrusions thereon with said rolls being synchronously rotated.

9. An apparatus, as set forth in claim 1, including a crank rod connected at one end to the flying cutter and the other end to one of the pinch rolls for synchronously moving the flying cutter in response to rotation of the pinch rolls.

10. An apparatus, as set forth in claim 9, wherein the cutter means of the flying cutter is associated with a cam for actuating the cutter means and severing the contoured strip at a preselected location along the pathway of the flying cutter.

11. An apparatus, as set forth in claim 10, wherein toured strip being cut during the operation of the appa-.

ratus.

12. An apparatus, as set forth in claim 1, including a magnetic roll positioned adjacent the flying cutter for receiving the contoured strip severed by the cutter, moving the strip to a preselected stacking location, and depositing said strip at said stacking location.

13. An apparatus as set forth in claim 12, including conveying means for moving the severed contoured strips from the stacking location in response to a received signal; and

electric eye means positioned adjacent and at a higher elevation than the stacking location for delivering the signal to the conveying means in response to the strips at the stacking location being at a preselected elevation.

14. An apparatus, as set forth in claim 12, including means for positioning the severed contoured strips of one stack in a staggered configuration relative to the severed contoured strips of adjacent stacks.

15. An apparatus, as set forth in claim 1, wherein the fixing means comprises a first shaft concentrically connected to the table;

a centering shaft passing through the table and into contact with the first shaft;

a clamp wheel collar positioned about the centering shaft for movement along the centering shaft;

a plurality of centering shoes pivotally connected to the clamp wheel collar for synchronous, transverse movement relative to the centering shaft in response to movement of the clamp wheel collar along the centering shaft; and

means for positioning said maintaining the shoes at preselected locations for centering and attaching the strip package relative to the unwind table.

16. A method for forming contoured strips from a packaged, continuous metal strip, comprising:

maintaining the continuous metal strip package on a rotatable table; placing a tension on the continuous strip and feeding the continuous strip from the strip package;

passing the continuous metal strip through a contour ing zone at which location forces are exerted on the strip by at least one contouring roll set, said forces being of a magnitude sufficient for continuously bending the continuous strip to a preselected configuration;

exerting forces on the contoured continuous strip for forming a generally linear, contoured continuous strip;

indenting the contoured continuous strip at preselected locations along its length;

severing the continuous contoured strip at preselected locations;

assembling the severed contoured strips; and

terminating feed of the continuous strip in response to one of the tension on the strip being less than a preselected value or the thickness of the strip being outside a preselected thickness range.

17. A method, as set forth in claim 16, including moving the severed contoured strips from the stacking location in response to strips at the stacking location being at a preselected elevation.

18. A method, as set forth in claim 16, including moving the severed, stacked, contoured strips from the stacking location in response to a preselected number of actuations of the severing means.

19. A method, as set forth in claim 16, including positioning the severed contoured strips of one stack in a staggered configuration relative to other severed contoured strip stacks.

UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Patent No. 3. ,793,862 Dated February '26, 197A Inventor) WILLIAM R. EDDY, ET AL It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

.Column 7 l ir1e 31, delete "said" and insert therefor and Signed and sealed this 13th dayof August l97l (SEAL) Attest:

MCCOY M. GIBSON, JR. 0. MARSHALL DANN Attesting Officer v Commissioner of Patents USCOMM-DC 603764 69 u.s. GOVIRNMENT rnm'rms omce Illa o-au-lsl.

FORM PO-105O (10-69)

Claims

1. An apparatus for forming contoured metal strips from a packaged, continuous metal strip, comprising: a frame; a strip unwind table rotatably attached to the frame; fixing means connected to the unwind table for maintaining a strip package fixedly centered and attached to said unwind table and rotatable therewith; a metering roll set positioned adjacent the unwind table for receiving the continuous metal strip and passing said strip at a preselected rate; means for driving the metered roll set at the preselected rate; a contouring zone having at least one contouring roll set positioned adjacent the metering roll set for receiving the continuous metal strip in the nip of the contouring roll set and bending said strip to a preselected configuration defined by the configuration of the roll surfaces of the contouring roll set; a strip straightening die positioned adjacent the contouring zone, said die having an opening for passing the formed continuous strip therethrough and being movable relative to the contouring roll set nip for exerting forces thereon for bending the contoured strip and forming a continuous, generally linear, contoured strip; a set of pinch rolls having protrusions on the surface thereof and being rotatable and positioned adjacent the die for receiving the contoured continuous strip in the nip of the said pinch rolls and indenting the contoured strip with the protrusions at preselected locations along said strips; a flying cutter having a cutting means and being movable along the pathway of the continuous, linear, contoured strip and actuatable for cutting said strip in two at preselected locations; and means for assembling the severed contoured strips.

2. An apparatus, as set forth in claim 1, including a brake attached to the rotatable unwind table for terminating the rotation of said table in response to a received signal; and tension means associated with the continuous strip passing from the strip package during the operation of the apparatus and being adapted to deliver the signal to the brake in response to the tension of said strip falling below a preselected value.

3. An apparatus, as set forth in claim 2, wherein the brake mechanism comprises a belt passing about at least a portion of a brake pulley of the rotatable strip unwind table, said belt having ends fixedly maintained at one location and a central portion being movable in response to the signal for moving the belt into forcible contact with the brake pulley; and the tension means comprises a brake idle roll, a lever arm rotatably connected to the brake idle roll and pivotally connected to the frame and being at a location for moving the metal strip to a nonlinear position at a location between the table and the metering rolls; a biasing means attached to the lever arm for urging the arm in an opposed direction relative to the force exerted on the arm by the metal strip through the brake idle roll; and means for attaching the central portion of the belt to the lever arm for urging the belt into forcible contact with the belt pulley in response to the force exerted on the brake idle roll being less than a preselected value.

5. An apparatus, as set forth in claim 1, including a gaging roll positioned adjacent a roll of the metering roll set and being spaced from said roll by the intervening metal strip during operation of the apparatus; a lever arm rotatably connected to the gaging roll at a first end and being pivotally mounted relative to the metering roll; microswitches associated with a first end of the lever arm and being operably connected to the means for driving the metering roll set and adapted to terminate the rotation of the metering rolls in response to movement of the lever arm second end greater than a preselected distance from a preselected location.

6. An apparatus, as set forth in claim 1, wherein the contouring zone has a plurality of contouring roll sets with the roll surfaces and nip of each set being of a different configuration than the surfaces and nips of the other roll sets for bending the strip differently at each roll set.

7. An apparatus, as set forth in claim 1, wherein the strip straightening die is contacted by a plurality of threaded adjustment elements for maintaining the die at preselected positions and moving said die.

8. An apparatus, as set forth in claim 1, wherein each of the opposed pinch rolls has a pair of protrusions thereon with said rolls being synchronously rotated.

11. An apparatus, as set forth in claim 10, wherein the crank rod is of a dimension and is connected to the pinch roll at a location at which the linear speed of the flying cutter during actuation of the cutter means is at least equal to the linear speed of the portion of the contoured strip being cut during the operation of the apparatus.

13. An apparatus as set forth in claim 12, including conveying means for moving the severed contoured strips from the stacking location in response to a received signal; and electric eye means positioned adjacent and at a higher elevation than the stacking location for delivering the signal to the conveying means in response to the strips at the stacking location being at a preselected elevation.

15. An apparatus, as set forth in claim 1, wherein the fixing means comprises a first shaft concentrically connected to the table; a centering shaft passing through the table and into contact with the first shaft; a clamp wheel collar positioned about the centering shaft for movement along the centering shaft; a plurality of centering shoes pivotally connected to the clamp wheel collar for synchronous, transverse movement relative to the centering shaft in response to movement of the clamp wheel collar along the centering shaft; and means for positioning said maintaining the shoes at preselected locations for centering and attaching the strip package relative to the unwind table.

16. A method for forming contoured strips from a packaged, continuous metal strip, comprising: maintaining the continuous metal strip package on a rotatable table; placing a tension on the continuous strip and feeding the continuous strip from the strip package; passing the continuous metal strip through a contouring zone at which location forces are exerted on the strip by at least one contouring roll set, said forces being of a magnitude sufficient for continuously bending the continuous strip to a preselected configuration; exerting forces on the contoured continuous strip for forming a generally linear, contoured continuous strip; indenting the contoured continUous strip at preselected locations along its length; severing the continuous contoured strip at preselected locations; assembling the severed contoured strips; and terminating feed of the continuous strip in response to one of the tension on the strip being less than a preselected value or the thickness of the strip being outside a preselected thickness range.