US3392566A

US3392566A - Metal rolling

Info

Publication number: US3392566A
Application number: US121653A
Authority: US
Inventors: Claus L Sporck
Original assignee: Lodge and Shipley Co
Current assignee: Lodge and Shipley Co
Priority date: 1961-07-03
Filing date: 1961-07-03
Publication date: 1968-07-16
Anticipated expiration: 1985-07-16
Also published as: BE619719A; FR1327605A; GB1016005A

Description

July 16, 1968 c. L. SPORCK 3,392,566

METAL ROLLING Filed July 5, 1961 4 Sheets-Sheet 1 INVENTOR ATTORNEYS July 16, 1968 c, sPo cK 3,392,566

METAL ROLL ING Fild July 5, 1961 4 Sheets-Sheet 2 mam! 26 INVENT'OR CM 5:? I

July 16, 1968 L, SPORCK 3,392,566

METAL ROLL ING Filed July 5, 1961 4 Sheets-Sheet 5 ATTORNEYS July 16, 1968 c. L. SPORCZK 3,392,566

METAL ROLLING Filed July 5, 1961 4 Sheets-Sheet 4 WAN . we a R d 66 yvzgmnn ATTORNEY United States Patent Office 3,392,566 Patented July 16, 1968 of Ohio Filed July 3, 1961, Ser. No. 121,653 7 Claims. (Cl. 7Z---220) This invention relates to sheet metal working and in particular relates to the working of sheet or strip stock to provide for the removal of the crown, for the widening of either of the length or width of the stock, for the forming of strength configurations such as ribs, tapers or the like and to do any of the foregoing while maintaining an extremely accurate thickness dimension and effecting improvements in the strength properties.

The invention is of especial significance in the production of sheet or strip stock for use in applications where flatness and thickness are critical and must be held within very close tolerances, for example, in aircraft, space vehicles, and missiles.

It is customary to produce sheet or strip stock by rolling in hot or cold mills with the rolled product sheared to size or being wound into coils or bands. Sheet and strip stock produced in the foregoing manner have thickness tolerances of about 10% of the specified thickness at least in thicknesses below A characteristically, rolling operations of the kind mentioned produce crown on the rolled stock and the reduction of crown depth has long been a problem where close thickness tolerances are required. For removing crown material the art has resorted to machining and for the most part to grinding techniques.

Machining is very costly, time consuming, and there are problems connected with the effects of heat generation, and with the difiiculty of holding of the sheet on a table, particularly a thin sheet. With grinding there are the effects of heat, limitation of strip width to about 40", and belt wear causes non-uniformity of thickness, both lengthwise and widthwise. One of the most significant disadvantages of both machining and grinding is the waste of material. For example, in grinding operations it is necessary to remove about of stock in order to make a significant reduction in crown depth. Even with such grinding it is very difficult if not impossible, to hold a 4% tolerance uniformly over the whole sheet.

The present invention provides a method for complete removal of the crown and enables the maintaining of thickness tolerance to a fraction of a thousandth on sheet or strip of any thickness and does this without any of the disadvantages of grinding or machining. While the invention removes the crown, the crown material is not physically separated from the stock and consequently there is no material waste. Further, the invention provides for improvements in the mechanical and strength properties of the material worked.

Beyond the foregoing, the invention provides a versatility of use which is impossible to obtain with grinding and machining. For example, the stock may be contoured as by having a taper extending either lengthwise or widthwise, or the stock can be provided with integral strengthening configurations such as, ribs, patterns, and the like.

One of the most significant features of the invention is that it provides for making sheet or strip stock having a width which is far greater than the widths of commercially available rolled stock, and even with such greater widths having a precise andaccurate thicknessv Insofar as I am aware, sheets of the kind mentioned were heretofore unknown.

The invention will be described in connection with the following drawings wherein:

FIGURE 1 is a perspective view of a machine adapted for practicing the invention;

FIGURE la is a perspective view of a strip being worked by the rollers of a conventional mill;

FIGURE 2 is an isometric view diagrammatically illustrating the widening of a sheet by the operation of a machine such as that of FIGURE 1;

FIGURE 3 is an enlarged broken out end view of the sheet of FIGURE 2;

FIGURE 4 is an isometric View illustrating a sheet having a plurality of ribs formed in accordance with the invention, the ribs running lengthwise of the sheet;

FIGURE 5 is an isometric view illustrating a sheet having a plurality of ribs formed in accordance with the invention, the ribs running widthwise of the sheet;

FIGURE 6 is an isometric view diagrammatically illustrating equipment for practicing the invention to remove crown from long strips;

FIGURE 7 is a diagrammatic representation of other equipment for practicing the invention;

FIGURE 8 is a diagrammatic view illustrating the expansion of the sheet as worked by the equipment of FIGURES 6 and 7;

FIGURE 9 is an isometric view diagrammatically illustrating other equipment for practicing the invention to remove crown from long strips;

FIGURE 10 is a cross section of a portion of the equipment of FIGURE 9;

FIGURE 11 is a fragmentary view diagrammatically showing other equipment for practicing the invention for sheet expansion or removal of crown from long strips;

FIGURE 12 is a plan view taken along the line 1212 of FIGURE 11;

FIGURE 13 is a cross section diagrammatically illus trating other equipment for use in sheet expansion or crown removal; and

FIGURE 14 is a section taken on the line 1414 of FIGURE 13.

In FIGURE 1, I have shown a conventional shaper arrange-d for practicing the methods of the invention. The ram 1 of the shaper has a tool holder 2 rotatably mounting a roller 3'. The rotational axis of the roller is indicated at A. The ram 1 is adapted to reciprocate hack and forth along an axis B, which lies in a plane which is normal to to the axis A. The knee 4 of the shaper mounts a table including the jaws 5 and 6. Between the jaws 5 and 6 is mounted a support 10. The plane through the surface of the support 10 is parallel to the axis B. The support has a clamp 11 which fixedly secures one end of a flat piece of stock 12 to the support 10. The knee 4 is adapted to move the table and the support stepwise in small desired increments, generally in the direction indicated by the arrow C. From the foregoing description, it will be apparent that the roller 3 can be reciprocated back and forth over the sheet in a direction parallel to the axis B, and that the roller can be brought into contact with various portions of the sheet by motion of the knee 4.

The basic concept of the invention is to carry out the working so that the sheet or strip is reduced in very small increments. According to the invention, sheet or strip is engaged with a roller within a limited contact area and the roller is move-d into the sheet so that one small increment after another is displaced or reduced. With an incremental quantum of material being worked at any instant, the force required for working is proportionately smaller. This minimizes the possibility of distortion of the roller, the support and the connected mechanism. Thus the space between the support surface and the roller working surface (this space determining thickness) can be very closely maintained. The reduction of the increments takes place progressively along a path extending fnom one edge of the sheet to the other and this kind of reduction is repeated successively along other parallel paths which are spaced from the first path in a direction normal thereto. The manner in which the foregoing is accomplished will be explained following:

First, referring to FIGURE 1a, a conventional rolling mill has rollers R-1 and R2 rolling the stock S to a width W. A sheet S may be cut from the rolled stock, for example, to a size as indicated by the dot-dash lines. The sheet will have a width W and a length L. Hereinafter, the term width as applied to a sheet or strip, will refer to a width taken in the direction of the width W of FIGURE 1a; also, the term length of a sheet or a strip will refer to a length taken in the direction of the length L of FIGURE 1a. In FIGURE 1, assume that the sheet 12 has been cut from the sheet S of FIGURE 1a and has a width Wl and a length L-l.

FIGURE 2 is an isometric view diagrammatically illustrating the roller 3 and sheet 12 of FIGURE 1; for purposes of description both the roller and the sheet have been enlarged.

In FIGURE 2 the sheet 12 is held in a fixed position, that is to say, there is not any movement of the knee 4 in a direction along the axis C. The edge 13 of the sheet is gripped by the clamp 11 with the opposite edge 14 free. The area 17 of the sheet is positioned to be engaged by the roller 3. Ram 1 is operated so that roller 3 is made to move from the position shown (where it is out of contact with the edge 15 of the blank) in a direction indicated by the arrow f1 toward the edge 15 to engage the sheet and thence move along the path indicated by the dotted lines 170. The roller motion continues until it comes out of contact with the edge 16 and the motion of the ram is stopped. The space between the roller and support is set so that the roller in moving along the reduction path 17 displaces the metal and forms a groove. This groove is indicated by the dotted lines 17b in FIG- URE 2. The knee 4 is then moved towards the left until such time that the area indicated by the dotted line 18 is positioned to be engaged by the roller. The knee is then held fixed and the ram moved so that the roller moves in a direction of the arrows r-1. The roller engages the sheet (edge 16) and then moves toward the edge 15 along the path 18a until it comes out of contact with the sheet at the edge 15. The roller in moving along the reduction path 18a displaces the metal and widens the groove 17]) for example, as indicated at 1811 in FIGURE 3.

The knee 4 moved toward the left until the area of the sheet indicated by 19 is positioned to be engaged by the roller. The ram 3 moves the roller in a direction indicated by the arrow f-2 until it contacts the edge 15 and continues along the path 19a towards the edge 16. The movement continues until the roller leaves the edge 16. The roller displaces the metal and again widens the groove for example, as indicated at 19b in FIGURE 3. The knee moves the portion of the sheet indicated by the dotted line 20 in a position for engagement by the roller. The roller is then moved in the direction indicated by r2 along the path 20a and further widens the groove as indicated at 20b. The foregoing operations are successively repeated until the whole sheet has been worked. For each of the successive reductions, the sheet is positioned with respect to the roller so that the reduction paths 17a-20a etc. are relatively close and each reduction is small. The finish of the surface of the reduced portion is dependent to some extent on the path spacing.

With reference to FIGURE 3, it will be seen that the portion of the sheet worked has been reduced in thickness for example, from original thickness T to reduced thickness T The metal displaced in the reduction causes the sheet to expand or lengthen in the direction of the repeat reductions (or in a direction normal to the original path) and in an amount proportional to the metal displaces for example, in FIGURE 2 the expansion is in the direction as indicated by the arrow E. If the thickness T is 50% of T then the width of the finished sheet will be about double the original width. This is illustrated in FIGURE 2 where it will be seen that the expanded width W2 is about twice the original width Wl. The total amount of reduction may be effected in stages for example, a 30% reduction may be done by working over the blank two times with a 15% reduction each time.

An example of the significance of the expansion feature is illustrated following. Sheets of 1S-8 stainless steel A3" thick (11 gage) are available in widths up to 72 inches. Sheets having about half of this thickness (16 gage) are available in widths up to 60 inches. Commercial tolerances on such sheets is about 10% of specified thickness. With the method of the invention an 11 gage sheet 72" wide can be reduced 50% in thickness and the width will be approximately doubled. Such an expanded sheet width is more than twice the width of the commercially available 16 gage, and furthermore, the thickness of the finished sheet is held within a tolerance of a fraction of a.

thousandths uniformly over the sheet.

As the roller moves along any of the paths 17a through 20a it will be apparent that the blank is reduced in small adjacent increments which lie along the path. For example, in the path 17a the first incremental reduction is taken closely adjacent the edge 15. The next incremental reduction is adjacent the first in a direction towards the edge 16. The various dashes forming the path 17a may be considered as representing the incremental displacements or reductions that are progressively effected along the path by the fact that the roller moves over a finite distance displacing or reducing as it moves. As indicated, the width of each increment taken normal to the reduction path is substantially less than the total width of the stock to be worked. The exact amount of metal being worked on at any instant depends on the configuration of the roller surface, the spacing between the roller surface in the support and the spacing between reduction paths. These factors are varied in accordance with the type of material being worked to effect most efficient operation.

In FIGURE 2, it will be noted that the successive adjacent paths 18a, 19a, and 20a are all parallel to the first path 17a and spaced therefrom in a direction normal thereto and that path 17a lies in a vertical plane extending between the

edges

15 and 16. The vertical plane, of course, contains the thickness dimension of the stock. Also in FIGURES 1 and 2 it will be noted that the sheet 12 is supported on one face by the support 10 with the reduction being taken on the opposite face. The support of course, cooperates with the roller to effect the reduction in the sense that the support provides that the increment being reduced is incapable of motion normal to and away from the face. While the sheet as a whole is supported by the surface of the support 10, it will be observed the arrangement provides that as the roller moves along a path each successive increment is simultaneously supported and reduced. Taken as a whole, the sheet is mounted by the support 10 so that as respects any one path of roller operation support is provided in a small area which can be considered in the nature of a line contact between the support surface and the face of the sheet.

The forming of ribs is another important feature of the invention. Ribbing is accomplished without sacrifice or dimensional accuracy in thickness either in the ribbed sections themselves or in the portions of the sheet which interconnect the ribs. Ordinarily ribs are formed in order to promote additional strength without incurring additional Weight. One kind of ribbing is diagrammatically illustrated in FIGURE 4.

In FIGURE 4 the ribs on the sheet 21 are formed by varying the space between the roller and the support as the roller is moved in the various successive paths. This forms a plurality of spaced sections, each section having preferably the same thickness and the spaced sections constituting the ribs 22. In the areas between the section, the space between the roller and support is made narrower so that the connecting portions 23 have a smaller thickness. In making the ribbed sheet of FIGURE 4 in machines of the kind in FIGURE 1, the space is varied by moving the knee 4 up and down in timed relation with the ram motion. The original sheet is clamped on the side of the sheet indicated at 24 (the area covered by the clamp is cut off after all of the ribs are formed). A roller 25 is passed back and forth over the sheet in directions indicated by the arrows 26. The first series of reductions are taken in the section 22a, then a greater amount of reduction is taken in the connecting portion 23a, and so on until all the sections and portions are formed.

It will be observed that the direction of the ribs is the same as the path of the roller across the sheet. Preferably the sheet is worked so that the sections forming the ribs are of equal thickness. Also the interconnecting portions are of equal thickness. The rib forming operation expands the width for example, if the original sheet has a width W-1 it will be expanded to a width W-3.

In FIGURE 5, I have shown a sheet wherein the ribs are formed in a. direction which is normal to the direction of the roller motion. The roller 30 is made to move along a reduction path indicated by arrow 26 and the space between the support and the roller is varied. For example, in FIGURE 5 the roller 30 reduces the section 31a and then as it progresses across the sheet, the space at 32a is made thinner and this pattern is repeated across the width of the sheet. In each successive path of roller motion the reductions are all taken so that there is a continuity between the sections 31a (and interconnecting portions 32a) whereby in the finished sheet the sections 31a constitute the ribs. In the foregoing operation the width of the original sheet is increased to a width W-4.

Aside from the forming of strengthening ribs as described above, the invention contemplates that the sheet may be formed with a contour, for example, a taper which extends either lengthwise or widthwise of the sheet.

Where the taper is to extend lengthwise, the space between the support and the roller is gradually increased or decreased. For example, in FIGURE 2 as the roller moves along the path 17a the space is made increasingly smaller. The same pattern is repeated with each successive reduction. Thus the finished sheet will have a taper which decreases in the direction from the edge to the edge 16. Where the taper is to extend in the opposite direction or say decreasing from the edge 13 to 14 the space between the roller and the support is decreased in each successive reduction path. In other words, the space along the path 17a is slightly less than along the path 17a and the space along the path 19a is again less, and so on.

In addition to the ribbing and tapering as described above, it will be apparent that the methods of the invention can be used to apply a variety of contours to a sheet. For example, by controlling the space between the roller and the support the sheet is provided with a checker-board pattern, i.e., a series of hills and valleys. So too, a sheet rather than being tapered from one end to the other, may be provided with tapers which start from the center and then decrease in a direction towards two opposite edges. Also the sheet may be worked so that it has a concave or convex cont-our, the curvature of which is precisely controlled.

It will be understood that working the metal as above described will eliminate any crown material that may be on the sheet. Furthermore, as material is worked, strain hardening occurs and the mechanical properties of the sheet are improved.

In addition to the expanding and contouring aspect as mentioned above, the invention finds a special utility in removing the crown from cold or hot rolled coils. Typical equipment for accomplishing this is diagrammatically il lustrated in FIGURES 6 and 7.

In FIGURE 6 the equipment has a frame 40 which carries a roller or support 41 by means of hardened plates 42. Means (not shown) support the working roller 43 and passes the roller back and forth across the sheet in a direction indicated by the arrows 44. During the working operation, roll 41 is immovable being pressed against the bottom plate 42 by the working pressure and supports the strip 45 in the same manner as the support 10 of FIG- URE 1. The strip is advantageously run under a break roll 46 and means, not shown, put the strip under tension and move the strip step-by-step to position the same for each succeeding pass of the roller 43. In order to facilitate movement of the strip without scarring the face engaged with the roll 41, the roll is mounted on brackets, such as shown at 47, which is adapted to be moved slightly upwardly and hence free the roll from the bottom plate 42. The roll is mounted in bearings on the bracket 47 so that as the strip is moved the roll turns freely.

In working with strip, the reduction may advantageously be carried out with rollers operating on opposite faces of the strip. Such an arrangement is diagrammatically illustrated in FIGURE 7. The equipment comprises a top face roller 50 and a bottom face roller 51 which are adapted to be simultaneously moved back and forth in the direction of the arrows 52 across the strip 53. On either side of the

rollers

50 and 51 are top and bottom strip guiding and holding

rollers

54 and 55. The edge holding and guiding rollers 56 are disposed as shown. The strip is preferably put under tension and moved in step-by-step fashion to position the same for each successive reduction.

In the arrangement of FIGURES 6 and 7, a strip is reduced with the roller moving width wise. The effect here is similar to the sheet extension effect explained in connection with FIGURES 2-5. In FIGURES 6 and 7, however, the strip expands lengthwise or in the direction indicated by the arrows 60. This is diagrammatically illustrated in FIGURE 8 wherein the strip 45 (top) is shown to have an original length L The finished strip 45 (bottom) is shown to have a length of L plus E, where E is the expanded or additional length. With regard to lengthwise expansion, the following is to be noted. Since the crown is thicker at the central portion of the sheet than at the ends, the larger volume of metal displaced will have a tendency to cup the expanded strip. In other words, the expanded strip will have a slight concave shape. The strip is easily flattened in a straightening machine.

In the practice of the invention for expanding, contouring and crown removal the stock was moved in stepby-stcp fashion for positioning the desired area with respect to the roller. In other words, in between each succeeding roller pass, the stock was shifted. It will be apparent, however, that the stock can be held fixed while the roller is moved between passes.

Instead of the step-by-step positioning of the stock or roller, the invention may be practiced under conditions of continuous operation; For continuous operation, the invention contemplates that adjacent increments along a reduction path be worked or reduced simultaneously and that successive reductions in the adjacent areas be accomplished by virtue of continuously moving stock. Continuous stock movement is advantageously applied for working coils of hot or cold rolled strip.

One arrangement for the foregoing is shown in FIG- URE 9 wherein the epuipment includes a sup-port in the form of a roller 60 rotatably mounted on the standard 61. The strip 62 is wound up in a coil (not shown) and from the coil runs over the roll 60 and then under the break roll 63 from whence it is cut to desired length or wound into a coil. Preferably the strip is put under tension while continuously moved in the direction indicated by arrow 64.

For carrying out simultaneous reduction along a path and for reducing successively adjacent areas, a plurality of small rollers are mounted so that there is a continuous procession of rollers across the strip while the same is being moved. Thus in FIGURE 9, a plurality of small rollers 65 are linked together and driven with continuous motion about a track mechanism indicated by the dotdash line 66. The arrangement provides that as the rollers are moved across the strip, they are uniformly forced into the metal by reacting against the under surface of a reaction bar 71. The bar has means 72 for retaining the rollers against axial movement. The reaction bar and rollers are adjustable vertically (by means not shown) for controlling the space between the working surfaces of the rollers and the support 60. The rollers move about the track 66 at a speed which is coordinated with the speed of the strip and with the amount of reduction to be effected.

In FIGURES 11 and 12 I have shown an arrangement for practicing the invention involving the concept of a large number of small rollers which are simultaneously rapidly oscillated back and forth over the stock. This arrangement may be advantageously used in equipment of the type described heretofore. In FIGURE 11 the support 75 which can be a roll or a table supports the sheet or strip 76. A large number of relatively small rollers are rotatably supported and confined in the cage 81. A reaction plate 82 bears on the rollers and the plate and rollers are vertically adjustable so as to control the space between the rollers and the support 75. The cage is adapted to be rapidly reciprocated back and forth in the direction indicated by the arrows 83. The magnitude of the reciprocation is preferably equal to slightly more than the diameter of a roller plus the spacing between adjacent rollers. Reciprocating means is mechanical or hydraulic. The motion of the stock 76 to bring successive areas to be reduced within the range of the rollers has a distancetime relationship which is phased with the distance-time relationship of the rollers to take into account the roller dwell (at the end of reciprocation). The dwell of the roller and the strip is coordinated with the magnitude and frequency of reciprocation so that for all practical purposes the reduction is carried out with a continuously moving strip.

In FIGURES l3 and 14, I have diagrammatically illustrated other equipment based on the reciprocating principle. In this arrangement ball-type rather cylindrical type is shown in FIGURES 11 and 12. In FIGURES l3 and 14 a plurality of balls 85 are confined in a bar 86. A sheet or strip extends between the balls 85 and the support of roller 87. A plurality of back up rolls 88 interconnect the bar and a frame 89. The bearing 90 mounted on the supports 91 confine the bar with respect to the frame. The bar and rollers are arranged to be reciprocated in the direction of the arrow 92. The frame, bar and rollers are vertically adjustable for controlling the spacing between the rollers and the support.

Before closing, it is pointed out that the methods of the invention may be practiced for the expanding, contouring, etc. of hot and cold rolled plate stock and is not confined for use only with sheet or strip stock.

I claim:

1. A method of removing crown on metal strip stock comprising the steps of:

taking a piece of strip stock having crown;

working the strip by rolling a groove on one face of the strip, the width of the groove being substantially less than the total width of the portion of the strip to be worked and the rolling of the groove causing the portion rolled to be reduced to a desired thickness dimension and also causing the strip to expand in the plane of the strip and in a direction normal to the groove;

continuing with said working by rolling the strip adjacent first said groove to effect an increase in width of the first said groove, the amount of the increase being substantially less than the width of the portion of the strip to be worked and the rolling causing the portion rolled to be reduced to the desired thickness dimension and also causing the strip to expand in the plane of the strip and in a direction normal to the groove; and

continuing with said working by repeating said second step successively on respectively adjacent areas of the strip to continue said groove widening and said expansion, the worked portion of the strip being free of crown.

2. A method of widening metal sheet stock and providing precise thickness dimension therein, comprising the steps of:

taking a substantially flat piece of sheet stock;

working the sheet by rolling a groove on one face of the sheet, the width of the groove being substantially less than the total width of the portion of the sheet to be worked and the rolling of the groove causing the portion rolled to be reduced to the desired thickness dimension and also causing the sheet to expand in the plane of the sheet and in a direction normal to the groove;

continuing with said working by rolling the sheet adjacent first said groove to effect an increase in width of the first said groove, the amount of increase being substantially less than the width of the portion of the sheet to be worked and the rolling causing the portion rolled to be reduced to the desired thickness dimension and also causing the sheet to expand in the plane of the sheet and in a direction normal to the groove; and

continuing with said working by repeating said second step successively on respectively adjacent areas of the sheet and across the face of the sheet to continue said increase in groove width and said expansion, and thereby cause the worked portion of the sheet to have the desired width and thicknes dimension.

3. A method for providing precise thickness dimension in metal sheet or strip stock comprising the steps of:

taking a substantially flat piece of stock;

working the stock to reduce its thickness to a desired dimension by rolling of adjacent increments of the stock to the desired thickness dimension, the reducing being done simultaneously on each face of the stock and the reducing being progressive along a path lying in a plane containing the thickness dimension of the stock, the width of each said increment taken in a direction normal to said plane being substantially less than the total width of the portion of the stock to be reduced and the reduction along the path causing stock to expand in a direction normal to the plane; and

continuing said working by performing second said step successively on respectively adjacent areas of the stock, the path of each repeat step being parallel to said plane and spaced from the plane in a direction normal to the plane, the worked portion of the stock having said desired thickness dimension.

4. A method of providing ribs on a sheet or strip stock,

comprising the steps of:

taking a substantially flat piece of stock;

Working the stock by rolling to reduce the thickness of adjacent increments of the stock, the reducing being done along a path lying in a plane containing the thickness dimension of the stock, the width of each said increment taken in a direction normal to said plane being substantially less than the total width of the portion of the stock to be reduced and the reduction along the path causing the stock to expand in a direction normal to the plane and effecting the reduction to form, along said path, spaced sections and portions connecting the sections, the thickness of the sections being greater than the thickness of the portions; and

repeating last said step successively in respectively adjacent areas of the stock, the path of each repeat step being parallel said plane and spaced from the said plane in a direction normal to the plane and each repeat step being carried out to effect a continuity of spaced sections and connecting portions extending normal to said plane whereby the spaced sections constitute ribs.

5. A mehod of providing a taper in metal sheet or the stock, the width of the groove being substantially strip stock, comprising the steps of: less than the total width of the portion of the stock taking a substantially flat piece of stock; to be worked and the rolling of the groove causing working the stock by rolling to reduce the thickness of the portion rolled to be reduced to the desired thickadjacent increments of the stock, the reducing being ness dimension and also causing the stock to expand done along a path lying in a plane containing the in the plane of the stock and in a direction normal to thickness dimension of the stock, the width of each the groove;

said increment taken in a direction normal to said continuing with said working by rolling the stock adjaplane being substantially less than the total width of cent first said grove to effect an increase in width of the portion of the stock to be reduced and the reducthe first said groove, the amount of increase being tion along the path causing the stock to expand in a direction normal to the plane and the reducing being done so that the thickness along the path constitutes a taper; and

repeating last said step successively in adjacent areas of the stock, the path of each repeat step being parallel substantially less than the width of the portion of the stock to be worked and the rolling causing the portion rolled to be reduced to the desired thickness dimension and also causing the stock to expand in the plane of the stock and in a direction normal to the groove; and

to said plane and spaced from the plane in a direction normal to the plane.

6. A method of providing a taper in metal sheet or strip stock comprising the steps of:

taking a substantially flat piece of stock;

working the stock by rolling to reduce the thickness of adjacent increments of the stock, the reducing being done along a path lying in a plane containing the thickness dimension of the stock, the width of each said increment taken in a direction normal to said continuing with said working by repeating said second step successively on respectively adjacent areas of the stock and across the face of the stock to continue said increase in groove width and said expansion, and thereby cause the worked portion of the stock to have the desired width and thickness dimension.

References Cited UNITED STATES PATENTS plane being substantially less than the total width of 2 51 1 2 the portion of the stock to be reduced and the reduc- 2367226 1/1945 g d 29 tion along the path causing the stock to expand in a 2165266 7/1939 H a e direction normal to the plane; and u Son 6 a repeating last said step successively in adjacent areas of FOREIGN PATENTS the stock, the path of each repeat step being parallel 154 056 7/1958 Sweden.

said plane and spaced from the plane in a direction 36O767 10/1922 Germany.

normal to the plane and each repeat step effecting 492:230 9/1938 Great Britain reduction so that the thickness of the stock in a direction normal to said plane constitutes a taper.

7. A method of widening metal sheet or strip stock and providing precise thickness dimension therein, comprising the steps of:

taking a substantially flat piece of stock;

working the stock by rolling a groove on one face of CHARLES W. LANHAM, Primary Examiner.

MICHAEL V. BRINDISI, RICHARD J. HERBST LEON PEAR, Examiners.

40 J. E. SCHARDT, C. H. HITTSON, H. D. HOINKES,

Assistant Examiners.

Claims

1. A METHOD OF REMOVING CROWN ON METAL STRIP STOCK COMPRISING THE STEPS OF: TAKING A PIECE OF STRIP STOCK HAVING CROWN; WORKING THE STIP BY ROLLING A GROOVE ON ONE FACE OF THE STRIP, THE WIDTH OF THE GROOVE BEING SUBSTANTIALLY LESS THAN THE TOTAL WIDTH OF THE PORTION OF THE STRIP TO BE WORKED AND THE ROLLING OF THE GROOVE CAUSING THE PORTION ROLLED TO BE REDUCED TO A DESIRED THICKNESS DIMENSION AND ALSO CAUSING THE STRIP TO EXPAND IN THE PLANE OF THE STRIP AND IN A DIRECTION NORMAL TO THE GROOVE; CONTINUING WITH SAID WORKING BY ROLLING THE STRIP ADJACENT FIRST SAID GROOVE TO EFFECT AN INCREASE IN WIDTH OF THE FIRST SAID GROOVE, THE AMOUNT OF THE INCREASE BEING SUBSTANTIALLY LESS THAN THE WIDTH OF THE PORTION OF THE STRIP TO BE WORKED AND THE ROLLING CAUSING THE PORTION ROLLED TO BE REDUCED TO THE DESIRED THICKNESS DIMENSION AND ALSO CAUSING THE STRIP TO EXPAND IN THE PLANE OF THE STRIP AND IN A DIRECTION NORMAL TO THE GROOVE; AND CONTINUING WITH SAID WORKING BY REPEATING SAID SECOND STEP SUCCESSIVELY ON RESPECTIVELY ADJACENT AREAS OF THE STRIP TO CONTINUE SAID GROOVE WIDENING AND SAID EXPANSION, THE WORKED PORTION OF THE STRIP BEING FREE OF CROWN.