US3646794A

US3646794A - Method for cold-rolling grating workstock

Info

Publication number: US3646794A
Application number: US814289A
Authority: US
Inventors: Paul Tishken
Original assignee: Tishken Products Co
Current assignee: Tishken Products Co
Priority date: 1969-04-08
Filing date: 1969-04-08
Publication date: 1972-03-07
Anticipated expiration: 1989-03-07

Abstract

A method of forming grating material from elongated, generally flat workstock, comprising the steps of cold-forming a series of adjacently oriented notches or recessed portions along at least one edge of the workstock by peripherally engaging a rotatable externally ribbed or toothed roller element with the workstock, and thereafter passing the workstock between a plurality of spaced rollers and thereby straightening and flattening the workstock, and finally cutting the workstock into preselected lengths preparatory to assembling the same into a unitized grate structure.

Description

United States Patent Tislrken 1 Mar. 7, 1972 4 [54] METHOD FOR COLD-ROLLING GRATING WORKSTOCK [72] Inventor: Paul Tishken, Birmingham, Mich.

[73] Assignee: Tishken Products (30., Detroit, Mich.

[22] Filed: Apr. 8, 1969 [21] Appl. No.: 814,289

[52] US. CL ..72/187, 72/197, 72/198 [51] Int. ..B2lh 8/00 [58] Field ofSearch ..72/184, 196, 197, 198, 190,

[56] References Cited UNITED STATES PATENTS 375,746 H1883 Harris 1,773,836 8/1930 Woelfel ..72/198 2,911,865 11/1959 Brickman ...72/198 1,636,592 7/1927 Cushwa ..29/160 1,678,362 7/1928 Sloan ..29/160 FOREIGN PATENTS OR APPLICATIONS 1,072,925 6/1967 Great Britain ..72/197 Primary Examiner-Lowell A. Larson Att0rneyI-Ia.rness, Dickey & Pierce [57] ABSTRACT A method of forming grating material from elongated, generally flat workstock, comprising the steps of cold-forming a series of adjacently oriented notches or recessed portions along at least one edge of the workstock by peripherally engaging a rotatable externally ribbed or toothed roller element with the workstock, and thereafter passing the workstock between a plurality of spaced rollers and thereby straightening and flattening the workstock, and finally cutting the workstock into preselected lengths preparatory to asembling the same into a unitized grate structure.

9Claims,8DrawingFigures PATENTEDMAR 71912 a, 646,794

SHEET 1 UF 3 HI! IIHIHLTJ IN VEN TOR ATTORNEY PAIENTEBMAR 7 I972 SHEET 2 UF 3 INVENTOR ATTORNEY METHOD FOR COLD-ROLLING GRATING WORKSTOCK BACKGROUND OF THE INVENTION Grating structures, such as are commonly utilized in tire escapes, sidewalk, and sewer grates, and the like, consist of a grid of spaced parallel metal strips arranged on edge and oriented such that a certain number of the strips are disposed at approximately right angles to others thereof, with any suitable joint being provided at the intersection of the series of strips. While such grating constructions have been found extremely useful for many applications, it has been found desirable to provide the upper sides thereof with a nonskid surface to minimize the possibility of a person inadvertently slipping or sliding thereon in the event water, ice, snow, or the like accumulates on the upper side of the grates. While a number of so-called nonskid surface designs have been heretofore proposed to obviate such slipping and/or sliding problems, it has been found that one of the most effective nonskid surfaces can be achieved by forming a series of notches or recessed portions along the upper edges of the strips making up a grating structure, which notches provide or define a plurality of biting edges arranged transversely of the strips and adapted to increase the frictional characteristics between the upper side of the structure and, for example, the sole of the shoe, boot or the like of a person walking thereon.

In order to provide the aforesaid notches or recessed portions in the striplike grating workstock which constitute the majority of grating structures, it has heretofore been the practice to pass preheated strips of workstock through or adjacent a reciprocating cutter or die which function to cut a series of longitudinally spaced notches or recesses in the material. While this procedure has been found to be the best available technique for forming the nonskid notches in the workstock, such a technique has been objectionable for a number of reasons. First of all, such a procedure produces vast quantities of metal chips which, for most purposes, are waste material that cause considerable problems in handling and disposition, to say nothing of the expenses involved in the wasted material itself. Another objectionable feature of the above described method of fonning the notches or recesses in the grating workstock resides in the expenses involved in heating the workstock preparatory to subjecting the same to the reciprocating notch-forming die or cutting tool.

In accordance with the principles of the present invention, a new and improved apparatus is provided for forming grating material which is provided with the aforesaid nonskid notches or recessed portions along either one or both edges thereof. More particularly, the present invention utilizes a cold-rolling operation consisting of passing the strip grating material adjacent a rotatable tool having a plurality of circumferentially spaced, outwardly projecting portions adapted to be forced inwardly into the workstock and thereby form the notches or recessed portions therein, the workstock thereafter passing through an associated straightening and flattening means to remove any eccentricities or curvatures in the workstock that may be produced upon forming the notches therein. Such a cold-fonning operation has been found to be a considerable advance over the above described practice of forming the notches by means of initially preheating the workstock and thereafter subjecting the same to the action of a reciprocating cutting tool or die, since the cold-forming technique entirely obviates the production of any metal chips, the ancillary problems of disposing of such chips, as well as the need for heating the workstock prior to forming the notches therein.

Certain additional advantages of the present invention reside in the fact that the notched or recessed grating workstock produced in accordance therewith will be found to be substantially stronger as a result of the cold-rolling operation, as compared with similar workstock that has heretofore been produced by initially heating the workstock and thereafter cutting the notches therein with a reciprocating tool. It is estimated that the structural integrity of the workstock is increased as much as 10-20 percent as a result of the coldrolling operation, which permits the use'of a smaller number of strips of grating material to support a given load per unit of area. Moreover, as a result of the cold-forming operation, the workstock has been found to be elongated as much as approximately 1 inch per foot, with the result that a given length of strip workstock will produce an even greater length of grating workstock as a result of the notches or recesses being formed thereinpursuant to the teachings of the present invention. Additionally, the actual formation of the nonskid-notches can be performed at a considerably fast rate than has been possible with heretofore known and used methods, thereby substantially increasing the production rate of such grating workstock.

SUMMARY OF THE INVENTION This invention relates generally to a new and improved method of fabricating metal workstock, and more particularly, to a new and improved method of fabricating metal grating material.

It is accordingly a general object of the present invention to provide a new and improved method of forming grating workstock.

It is a more particular object of the present inventionto provide a method of cold-rolling nonskid notches or recessed portions in grating workstock. I

It is another object of the present invention to provide a method of the above character which includes the steps of forming the notches or recessed portions in the grating workstock by passing the workstock adjacent a rotatable element having outwardly extending projections adapted to be forced into the workstock and thereby form the nonskid notches or recesses therein.

It is a further object of the present invention to provide a method of the above character which includes the steps of forming the series of nonskid notches or recessed portions simultaneously along the opposite edges of the workstock.

It is yet another object of the present invention to provide a new and improved method of cold fonning grating workstock which includes the steps of flattening, straightening, and automatically cutting off preselected lengths of the workstock subsequent to the nonskid notches or recessed portions being formed therein.

Other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF 'II-IE DRAWINGS FIG. 1 is an elevated perspective view of a typical grating structure adapted to be manufactured in accordance with the method of the present invention;

FIG. 2 is an enlarged fragmentary elevated perspective view of a portion of the grating structure shown in FIG. 1;

FIG. 3 is an elevated perspective view of a portion of the apparatus utilized in practicing the method of the present inventron;

FIG. 4 is a side elevational view of the portion of the apparatus of the present invention located at the right end of the structure shown in FIG. 3;

FIG. 5 is a side elevational view of a notch-forming roller and associated drive means incorporated in practicing the present invention;

FIG. 6 is a top elevational view, partially schematic, of the roller and associated backup rollers incorporated in the present invention;

FIG. 7 is a view similar to FIG. 6 and illustrates an alternate embodiment of the present invention, and

FIG. 8 is a transverse cross-sectional view taken substantially along the line 8-8 of FIG. 7.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT I Referring now in detail to the drawings, FIGS. 1 and 2 illustrate a typical grate structure which may be provided with an external frame or the like 12 and comprises a series of spaced parallel strips of grating workstock, generally designated 14, which strips 14 are arranged in perpendicularly oriented transverse and longitudinally arranged rows which intersect, via lap joints or the like, as best seen in FIG. 2.

The strips of grating workstock 14, in a typical construction of the grate structure 10, are fabricated of cold-rolled steel or the like and are provided with a series of adjacently oriented inwardly projecting notches or recessed portions, generally designated 16 that function to enhance the frictional charac teristics of the upper surface of the structure 10 whereby to provide a nonskid surface upon which people may traverse without slipping, falling, or otherwise endangering themselves. The present invention deals particularly with a new and improved method for forming the nonskid notches, as will hereinafter be described in detail.

Generallyspeaking, the apparatus of the present invention consists of a feeding station 18 which provides a source of the grating workstock 14 to be notched, a notch forming station 20 into which the workstock 14 is fed and which performs the notch-forming operations hereinafter to be described, a workstock straightening and flattening station, generally designated 22, adapted to receive the workstock 14 from the station 20, and finally a workstock cutoff station 24 which takes the workstock 14 after it has been straightened and flattened via the station 22 and cuts it off into preselected segmental lengths preparatory to assembly thereof into a suitable grate structure such as the structure 10.

Referring now in detail to the workstock-notching station 20, as illustrated in FIGS. 5 and 6, the station 20 is provided with a suitable drive motor or the like 26, that may be energized by any suitable source of electrical or hydraulic power, and has an output shaft 28 that is drivingly connected through a suitable gearbox or transmission 30 and shaft 32 to a pinion gear 34. The gear 34 is meshingly engaged with a primary drive gear 36 which is mounted at one end of a drive shaft 38 that is rotatably supported by a suitable antifriction means (not shown) in an appropriate support structure, representatively designated by the numeral 40. The end of the shaft 38 opposite that-which is connected to the gear 36 is provided with a suitable worm gear 42 that is drivingly engaged to an associated drive gear 44 which is mounted on the lower end of a generally vertically disposed shaft 46. The support structure 40 may be of any suitable construction adapted to support the

various gears

34, 36, 42, and 44, as well as the

shafts

28, 32, 38, and 46 in an efficient, compact, and operativeconfiguratron.

The shaft 46 is adapted to rotatably support a generally cylindrically shaped notch forming element 48 which is adapted to perform a cold rolling or working operation upon the grating workstock 14 and thereby fonn the series of nonskid notches 16 therein. More particularly, the element 48 comprises a generally cylindrically shaped body section 50 defining a central vertically extending bore 52 within which .the upper end of the shaft 46 is received and drivingly connected to the element 48. The outer periphery of the element 48 is formed with a plurality of equally circumferentially spaced, vertically or axially extending outwardly directed notched fonning projections or riblike teeth 54 which preferably extend along the entire length of the element 48. Preferably, the axial length (height) of the element 48 is several times the thickness of the workstock 14, for purposes laterto be described. As best seen in FIG. 6, the notch-forming teeth 54, in transverse section, are generally trapezoid shaped and have a generally axially extending outer surface portion 56 and inwardly diverging face portions 58 and 60. As will be described in detail, in operation of the notch-forming station 20, the teeth 54 are adapted to peripherally engage one edge of the grating workstock 14 and thereby cold-form the notches 16 therein.

As best illustrated in FIG. 5, disposed adjacent the notch forming element 48 is a backup roller assembly, generally designated 62, which comprises a suitable support structure having upper and

lower sections

64 and 66 adapted to support a suitable rotatable shaft 68 in generally spaced parallel relation with respect to the shaft 46. The shaft 68 is provided with a backup roller member 70 which is generally cylindrically shaped and defines an annular, radially inwardly extending guide recess 72 around an intermediate portion thereof. The axial width of the recess 72 is adapted to be slightly-greater than the thickness of the workstock 14, whereby one edge of the workstock 14 may be received therein and thereby guided in peripheral relation with respect to the notch-forming element 48, as shown in FIG. 6. It will be seen that the shaft 68 is spaced radially away from the shaft 46 a preselected distance such that the space between the radially innermost portion of the recess 72 and the outer periphery of the bodysection 50 of the element 48 is approximately equal to the width of the workstock 14, so as to assure that the workstock 14 will be positively peripherally engaged with the element 48 as the notches 16 are formed therein by the teeth 54.

A particular feature of the above invention resides in the fact that means may be provided on either one or bothof the,

shafts

46, 68 for moving the roller assembly 62 and/or element 48 axially of its respective supporting shaft. Such means maybe provided'by one or more large washers or spacing disks 74 disposed between the upper and lower ends of the assembly 62 and element 48 and the adjacent support structure rotatably supporting the

shafts

46, 68. The purpose of such a design is to permit the workstock 14 to selectively peripherally engage the element 48 at different axial positions thereon, whereby to equalize tool wear after continued use of the apparatus of the present invention. More particularly, it will be seen that if one or more spacers are provided beneath the lower side of the assembly 62 and/or above the element 48, the annular guide recess 72 will be located relatively closer to the upper end of the element 48, whereby when the workstock 14 is passed interjacent the recess 72 and element 48, it will peripherally engage the element 48 adjacent the upper end thereof. Similarly, if one or more of the spacing disks 74 are provided adjacent the upper end of the roller member 70 and/or at the lower end of the element 48, the annular guide recess 72 will be axially disposed relatively closer to the lower end of the element 48 so that as the workstock 14 is guided thereby, it will be engaged with the lower end of the element 48. Thus, by properly incrementally axially adjusting or positioning the assembly 62 and/or element 48 along the

shafts

68, 46 through proper selection and periodic changing of the spacing disks 74, the workstock 14 can be made to engage the element 48 at different axial locations thereon so that relatively uniform wear of the element 48 may be achieved, thus maximizing tool life. It will be apparent,-of course, that various alternatemeans may be used for selectively adjusting the axial relationship or relative axial positioning of the annular guide recess 72 with respect to the element 48, such as by providing some type of axial adjustment means on the

shafts

46, 68, as will be apparent to those skilled in the art.

In a preferred construction of the present invention, two pairs of

guide rollers

76, 78 and 80, 82 are provided adjacent the forward and rearward sides of the element 48 and roller assembly 62, which guide rollers are provided upon suitable vertically extending

shafts

84, 86 and 88, 90, respectively, whereby to assure proper orientation of the workstock 14 as it passes toward and away from engagement with the notchforming element 48. If desired, one or more of the pairs of

rollers

76, 78 or 80, 82 may be rotatably driven whereby to push or pull the workstock 14 through the notch-forming station 20. Also, such rollers 76-82 may be formed with radially inwardly extending recesses such as the guide recess 72 to assist in axially aligning the workstock 14 with respect to the element 48, provided, however, that such guide recesses do not impair relative axial positioning of either the element 48 or backup roller assembly 62 pursuant to the above-described feature minimizing tool wear on the element 48. If desired, horizontally disposed rollers (not shown) may be provided adjacent the

guide rollers

76, 78 and 80, 82 for positioning the workstock 14 axially of the element 48.

Referring now to the construction of the workstock feeding station 18, as best seen in FIG. 4, the station 18 comprises a base or support structure 92 adapted to support an upwardly extending pedestal '94 upon which a suitable horizontally disposed support shaft 96 is mounted. The shaft 96 is adapted to support a suitable reel or coil of the workstock 14, representatively designated by the numeral 98, and be provided with suitable radially outwardly projecting coil-supporting arms 100 adapted to operatively support the workstock roll or coil 98, for example, in the manner disclosed in US. Pat. No. 3,022,024, issued Feb. 20, 1962 to the applicant. Suitable braking or clutching means may be provided in the feeding station 18 for preventing rotational momentum of the workstock coil 98 from building up upon rotation thereof, and thereby control selective feeding of the workstock 14 into the notch-forming station 20.

After the workstock 14 has been conveyed from the feeding station 18 into the station 20, wherein the series of notches or recessed portions 16 are formed therein, the workstock 14 progresses or is conveyed to the straightening and flattening station 22 which may be of any suitable conventional construction and preferably comprises one or more longitudinally spaced workstock flattening assemblies, generally designated 102, that are supported on a generally horizontally extending support surface 104 defined by a suitable support or base structure 106. Each of the assemblies 102 comprises suitable roller support means, generally designated 108, adapted to operatively support upper and lower cooperative pairs of rollers 110 and 112, respectively, for rotation about vertically spaced, horizontally extending support shafts or the like (not shown). Suitable means, representatively designated 113, is preferably provided for selectively adjusting the relative proximate positions of the upper rollers 110 with respect to the lower rollers 112 of each of the assemblies 102, whereby to selectively control and adjust the applied pressure exerted by the rollers 110, 112 upon the workstock 14 which passes therebetween in order to effect flattening of the workstock 14, as is well known in the art.

Disposed adjacent the outlet" sides of the flattening assemblies 102 are a plurality of workstock-edging assemblies 114 which may be of any suitable construction and are preferably provided with laterally spaced pairs of rollers 116 rotatable upon vertical extending axes and adapted to have the workstock 14 pass therebetween so as to apply laterally inwardly directed forces thereon to control the conformation or shape of the laterally opposite edges thereof, as is well known in the roll-forming art. The need for such edging assemblies 114 results primarily from the fact that the original coil 98 of workstock 14 is frequently considerably wider than the strips that are subjected to the notch forming operations, and that the edges of the strips of workstock become out of square when they are cut from the original coils 98, thereby necessitating the assemblies 114 for cold-forming the workstock 14 into the desired symmetrical or rectangular configuration.

In a preferred construction of the present invention, the end of the support structure 106 adjacent the notch-forming station is provided with suitable guide roller assembly 118 comprising a pair of horizontally extending, vertically spaced rollers 120 adapted to guide the workstock 14 as it passes from the station 20 into the adjacent flattening assembly 102. Disposed at the opposite end of the support structure 106 from the assembly 118 is a workstock-straightening assembly 122 comprising an elevated support structure 124 adapted to operatively support a plurality of horizontally extending upper rollers 126. The assembly 122 also comprises a lower roller support structure 128 which supports a plurality of lower rollers 130 that are spaced below and in staggered relation with respect to the upper rollers 126, as is illustrated in FIG. 3. The construction and operation of the workstock-straightening assembly 122 is well known in the art and a detailed description thereof will be omitted for purposes of simplicity of disclosure, it being apparent that the workstock 14 is designed to pass between the upper rollers 126 and lower rollers 130 and thereby be accurately straightened as a result of the interaction of the rollers 126, 130 thereon.

Disposed adjacent the assembly 122 is a workstock cutoff assembly, generally designated 132, which is adapted to have the workstock 14 pass therethrough and be cut into segmental sections of predetermined length. The assembly 132 may be of any suitable construction, such as the construction described in US. Pat. No. 3,1 1 1,054, issued Nov. 19, 1963 to the applicant, although various alternate constructions will be apparent to the skilled artisan. After the workstock passes through the assembly 132, it passes between a pair of extraction rollers 134 and 136 which may be suitably powered so as to pull the segmental sections of the workstock 14 away from the cutoff assembly 132 at a relatively faster rate than the workstock 14 is conveyed thereto, whereby to prevent any interference between successive workpieces being out off by the assembly 132. From the extraction rollers 134, 136, the segments of workstock 14 are adapted to pass onto a runoff table, generally designated 138, which is supported adjacent the end of the support structure 106 by suitable support pedestals 140. The runoff table 138 may be provided with suitable means for periodically dumping or otherwise transferring a plurality of workstock sections thereon onto an appropriate conveyor assembly, pallet, or other workstock transferring medium after a preselected number of sections have accumulated on the table 138, as is well known in the art.

In operation, assuming the initial condition that the drive motor 26 is energized and that the straightening and flattening station 22 is properly energized, for example through suitable manually actuatable controls 142, workstock 14 is initially unreeled from the coil 98 and is passed between the

guide rollers

76, 78. Thereafter, the workstock 14 passes between the notch forming element 48 and the backup roller assembly 62, whereby the series of longitudinally spaced notches 16 are cold formed in the workstock 14 as the projections 54 are successively forced inwardly into the adjacent lateral edge of the workstock 14. As the projections 54 thus produce the notches 16, a certain amount of metal adjacent each of the notches 16 cold-flows or is displaced above and below the workstock 14 at each of the notches 16, with the result that there is a certain increase in the overall thickness of the workstock 14 around the edge of each of the notches 16. Moreover, as a result of forming the notches 16 along one lateral side of the workstock 14, the workstock 14 tends to assume a somewhat curvilinear configuration.

After the workstock 14 passes between the element 48 and backup roller assembly 62, it passes between the guide rollers 80, 82 and thereafter between the rollers and through the straightening and flattening station 22. As the workstock 14 passes through the station 22, it alternately passes through the flattening assemblies 102 and the edging assemblies 114, whereby the aforesaid curvilinear shape is removed and the enlarged thickness portions of the workstock 14 at the notches 16 are flattened or removed. Finally, the workstock 14 passes between the straightening rollers 126, which function to straighten the workstock along the plane of the major width thereof, at which time the workstock 14 passes through the cutoff assembly 132 and extraction rollers 134, 136, whereby the workstock 14 is cut into segmental sections that are transferred to the runoff table 138. After a certain number of sections of the workstock 14 have accumulated on the table 138, the same'will be actuated to dispose the workstock sections the case with the workstock l4 processed bythe apparatus shown in FIGS. 5 and 6. In order to accomplish forming the notches 16 along both edges of the workstock 14, the backup roller assembly 62 is replaced with a notch-forming element 48' which may be identical in construction and operation to the hereinabove described element 48 and may be suitably driven by a suitable drive means, representatively designated by the numeral 144, which may be identical in construction and operation to the drive means provided by the drive motor 26, transmission 30, and gears 34, 36, 42, and 44, or any other suitable drive mechanism. The'notch forming elements 48, 48' may be rotatably positioned so as to form the notches 16 along each side of the workstock 14 so that the notches 16 are laterally aligned, or alternatively, staggered or alternated, as is shown in FIG. 7, depending upon the particular type of grating structure desired. A particular feature resulting from the simultaneous forming of the notches 16 along both sides of the workstock 14, as compared with forming the notches 16 along only one side thereof, resides in the elimination of the curved configuration that the workstock l4 assumes when the notches 16 are formed on one side thereof, thereby obviating the need for subsequently laterally straightening the workstock 14.

It will be seen from the above described construction of the present invention that a new and improved method and apparatus is provided for cold-rolling nonskid notches within elongated or strip grating workstock. A particular feature of the present invention resides in the elimination of the formation and subsequent handling of metallic chips which were abundantly produced in the production of grating material on conventional reciprocal cutting machines. Additionally, the present invention eliminates the need for preheating the workstock preparatory to cutting the nonskid notches therein. Also of importance is the fact that cold-rolling the notches 16 in the workstock 14, as well as the cold-working of the workstock 14 as the same is subjected to the straightening, flattening and edging operations, has been found to considerably strengthen the workstock and effect a certain amount of elongation thereof. Accordingly, the grating workstock produced in accordance with the present invention will be capable of supporting a greater load than has heretofore been possible with conventionally manufactured grating material, and a greater amount of grating workstock will be produced for a given amount of workstock utilized. Another feature of the present invention resides in the fact that the notch forming element 48 (48') and associated backup roller assembly 62 may be selectively axially positioned relative to one another, whereby to reduce wear of the element 48 to a minimum. Moreover, by designing the element 48 such that it is of a relatively massive (thick) construction, said element will be extremely strong and not be subjected to chipping or other attrition. Additionally, the relative shape and spacing between the notches 16 on the workstock 14 may be varied considerably by changing the configuration of the notch forming element 48, and

. said notches 16 may be provided along both sides of the gratingworkstock 14 by merely substituting an additional element 48' for the backup roller assembly 62, as above described, whereby to provide for universality of application.

While it will be apparent that the preferred embodiment illustrated herein is well calculated to fulfill the objects above stated, it will be appreciated that the present invention is susceptible to modification, variation and change without departing from the scope of the invention.

lclaim:

1. In the method of manufacturing elongated strips of grating material from generally flat, rectangular cross section workstock, the steps which include,

successively engaging a plurality of irregular notch forming elements on the periphery of a rotating member with the workstock and thereby forming a series of adjacently oriented notch portions along one lateral edge of the workstock and simultaneously cold working the workstock to strengthen the same and effecting preselected elongation of the workstock, whereby workstock of preselected length produces a recessed grating workpiece of predetenninately greater length. 2. The method as set forth in claim 1 which includes the step of straightening and flattening the workstock both longitu dinally and laterally by passing the workstock between spaced I rollers.

of alternatively flattening and straightening the workstock subsequent to forming the notched portions therein.

5. The method as set forth in claim 1 which includes the step of simultaneously forming a series of adjacently oriented notched portions along the laterally opposite edges of the workstock.

6. The method as set forth in claim I which includes the step of guiding the workstock into peripheral engagement with the rotating member by passing the workstock in part through an annular recessed portion formed in a backup roller assembly, which includes the step of straightening the workstock both longitudinally and laterally by passing the workstock between spaced rollers, and which includes the step of successively cutting off preselected segmental sections of the workstock after the same has been straightened and flattened subsequent to formingthe notched portions therein;

7. The method as set forth in claim 6 which includes the step of simultaneously forming a series of adjacently oriented notched portions along the laterally opposite edges of the workstock.

8. The method as set forth in claim 6 which includes the step of adjusting the relative axial positions of the backup roller assembly and rotatable member, whereby to guide the workstock into peripheral engagement with the rotatable member at different axial locations thereon.

9. The method as set forth in claim 1 which includes the step of flattening the grating material subsequent to fonning said notch portions therein, whereby the thickness of the notched grating material is substantially the same as the original workstock.

* i i t

Claims

1. In the method of manufacturing elongated strips of grating material from generally flat, rectangular cross section workstock, the steps which include, successively engaging a plurality of irregular notch forming elements on the periphery of a rotating member with the workstock and thereby forming a series of adjacently oriented notch portions along one lateral edge of the workstock and simultaneously cold working the workstock to strengthen the same and effecting preselected elongation of the workstock, whereby workstock of preselected length produces a recessed grating workpiece of predeterminately greater length.

2. The method as set forth in claim 1 which includes the step of straightening and flattening the workstock both longitudinally and laterally by passing the workstock between spaced rollers.

3. The method as set forth in claim 2 which includes the step of successively cutting off preselected segmental sections of the workstock after the same has been straightened and flattened.

4. The method as set forth in claim 1 which includes the step of alternatively flattening and straightening the workstock subsequent to forming the notched portions therein.

6. The method as set forth in claim 1 which includes the step of guiding the workstock into peripheral engagement with the rotating member by passing the workstock in part through an annular recessed portion formed in a backup roller assembly, which includes the step of straightening the workstock both longitudinally and laterally by passing the workstock between spaced rollers, and which includes the step of successively cutting off preselected segmental sections of the workstock after the same has been straightened and flattened subsequent to forming the notched portions therein.

9. The method as set forth in claim 1 which includes the step of flattening the grating material subsequent to forming said notch portions therein, whereby the thickness of the notched grating material is substantially the same as the original workstock.