US2503824A - Method for rolling strip material - Google Patents

Description

J. L. HUNTER EI'AL METHOD FOR ROLLING STRIP MATERIAL April 11, 1950 2 Sheds-Sheet 1 Filed Dec. 17, 1946 o n m O G fl M O H O0 z E A r E T 0 M n m @747 I IN..#J3 I PWA/ Z Jim Y H B April 11, 1950 J.L. HUNTER ETAL NETH D FOR ROLLING STRIP MATERIAL 2 Sheets-Sheet 2 Filed Dec. 17, 1946 2; .HMMQQ mww n T w v m wm VA. 1 a WM s NA a 6M .1 d ow v, & J57

Patented Apr. 11, 1950 2,503,824 METHOD FOR ROLLING STRIP MATERIAL Joseph L. Hunter, Edwin J. Hunter, and Thomas Martin, Riverside, Calif., assignors, by memo assignments, to Hunter Douglas Corporation, Riverside, Calit., a corporation of Delaware Application December 17, 1946, Serial No. 716,794

2 Claims. 1

Our invention relates to methods and apparatus for rolling thin strip material, and has particular reference to a rolling mill that produces multifold reductions in th thickness of the metal without checking the edge 01' the final product.

While our invention is applicable to most types of malleable metals, it has been found especially satisfactory when applied to reducing the thickness of aluminum sheet material. The invention accordingly will be described with reference to the production of long strips of thin aluminum, particularly when the final strip is to be utilized directly, without trimming the edges. Such aluminum strips are widely used, for example for the slats of lightweight Venetian blinds. Venetian blinds are preferably made from thin sheet material having a thickness on the order of .01". For this purpose a coil of V8" (.125") aluminum strip is passed through a rolling mill. This reduction of substantially 12 to 1 has proved to be expensive in the past inasmuch as the finished strip was frequently checked and cracked along the edges, and presented such a weak and rough section that it was necessary to trim the edges of the final product. Not only was this process expensive and time-consuming, but it resulted in the waste of substantial quantities of metal. y

We have discovered that this checking of the edges of reduced strip has been due to minute irregularities on the edges of the strip of the starting material that is to be reduced. No matter how perfect the shear or knives that formed the edges of the starting material, there were always non-uniform sections in the edge that gave rise to the final checks and cracks. We have further discovered that if a precision edge is formed on the material either before or during an initial reduction, these checks and cracks in the finished product may be avoided. While such an edge cannot be readily formed by rolling or swaging, we have found that when each edge is carefully shaved, a precision edge of the desired type is formed that will not result in checking.

In the manufacture of a rolling mill to carry out our edge-forming invention, considerable difficulty was encountered by following conventional methods of rolling mill design that would give acceptable accuracy and acceptable performance. We therefore found that it was desirable, if not necessary, to develop new types of frames and roller mountings for the various stands of our rolling mill in place of the one-piece frames customarily used. Accordingly our invention includes the provision of accurate and improved rolling mill stands.

2 We have also found it advisable to include a mechanism for automatically stopping the entire rolling mill in the event that the strip of material being reduced becomes broken or splintered. Our invention accordingly includes a mechanism for accomplishing this purpose.

It is a general object of our invention, therefore, to provide rolling mill apparatus and methods for multifold reductions wherein the final product has clean, straight edges that permit the direct utilization of the finished product.

Another object of our invention is to provide a method of reducing strip meta1 that includes the step of forming precision edges on the initial strip metal.

Another object of our invention is to provide a method of rolling strip material including the step of shaving the edges to form a precision edge on the initial strip metal.

Another object of our invention is to provide a rolling mill having a plurality of stands wherein the stands are preceded by a shaving mechanism.

Another object of our invention is to provide a rolling mill having a plurality of stands and in which a. shaver is disposed between two of the stands along the first part of the reducing run.

A further object of our invention is to provide 5 a rolling mill having a plurality of stands wherein a shaver precedes all of the stands and a second shaver is disposed between two of the initial stands.

Another object of our invention is to provide a rolling mill wherein the frames of the stands may be formed of four parts keyed together.

Another object of our invention is to provide stands for a rolling mill wherein the frames are formed of separate front and back members spaced top and bottom by two additional members so that all elements of the frame may be easily machined.

Another object of our invention is to provide a rolling mill having guides through which the strip material ma pass during its travel through the mill.

Still another object of our invention is to provide an automatic mechanism for stopping the entire mill which is operable upon the displacement of the guides due to abnormal strains developed by broken or splintered metal stock.

Other objects and advantages of our invention will be apparent in the following description and claims, considered together with the accompanying drawings, in which Fig. 1 is an elevation view of-a rolling mill embodying our invention;

Fig. 2 is a side view of one of the stands of the rolling mill of Fig. 1:

Fig. 3 is a front view of the stand of Fig- 2;

Fig. 4 n an exploded perspective view of the frame of the rolling mill stand of Figs. 2 and 3;

Fig. 5 is a top view of one of the shaver mechanisms forming a part of our rolling mill invention;

Fig. 6 is an elevation view of the shaver mechanism of Fig. 5;

Fig. 7 is a top view of one of the guides em-- ployed in our rolling mill;

Fig. 8 is an elevation view of of the guide of Fig.7; and

Fig. 9 is a sectional view of the guide taken along the line -IXIX of Fig. 7.

Referring to Figs. 1 through 4, our invention may be embodied in a rolling mill in including a platform H upon which may be secured any desirable number ,of rolling mill stands l2. Each stand I2 may be driven by a gear box l3 which receives power from a chain drive ll driven by a sprocket it. As the material is successively reduced in the various stands, its velocity through the mill will be increased and accordingly there must be a progressive increase of roller speeds as the material drives through the mill. Accordingly, therefore, the sprockets i6 may be of progressively increasing size as noted in Fig. l to obtain the necessary I increase of roller speed. The sprockets may be driven by individual motors I! which may be of the electric type. Power may be furnished to the motors through a conduit I9 connected to a relay box i9. The various sprocket drives may be mechanically interconnected or they may be electrically interconnected as by using synchronous motors for the motors H.

The starting material may be spooled into a coil 2| rotatably supported by a frame 22. The coiled material, which may be of any desired commercially available thickness, for example 34;", may then be passed through two rollers 23 which act not only as guides, but which may also have a manual drive for. starting the material through the entire mill. The material thereafter passes through a first shaver 24 and then through the first and second stands and through a second shaver 24:: disposed between the secondand third stands. The final product will emerge from the right end of the mill (as viewed in Fig. 1) and may be spooled into a coil 26 surrounded by and rotatably, mounted on a frame 21. As previously noted, this final material will be free from cracked edges and may be directly utilized as by cutting of! strips of appropriate length that are apertured for use in Venetian blinds.

Referring particularly to Figs. 2, 3 and 4, it will be noted that each frame l2 may include a forward member 28 which may be identical with a rear member 28a. These two front and back members may be spaced at the bottom by a lower spacer block 29, and may be spacedat the top by an upper spacer block 3!. Each frame [2 may include an upper roller 32 which may be identical with a lower roller 32a. Each roller may be mounted in two bearing blocks 33 of general rectangular outline to fit between the front and back frame members on each side thereof. A spring 34 may urge the two blocks apart and a iackscrew 36 may urge the two blocks together by exerting pressure through a load block 31. The bearing blocks may include appropriate antifriction devices such as roller or needle bearlugs and may be provided with suitable lubricating devices.

The detailed construction of the frame of the stands l2 may best be described with reference to Fig. 4. There it will be noted that the two front and back members 28 and 2812 are each provided with a tunnel 38 through which the material being rolled may pass. Likewise the bottom ends of these frame members may be flanged as at 39 and suitably apertured for the reception of hold-down bolts for securing the stands a to the platform H, as noted in Fig. 1. The frame members 28 and 28a are further provided with a planar inner surface ll which permits the entire surface to be milled and then extremely accurately ground. There are no projections in the surface that would interfere with the formin of an exact and accurate finish thereon.

The bottom spacer block 29 may be provided with a lubricant outlet 42 for directing lubricating liquid under pressure to the lower roll, which outlet may be connected to a bore 43 to which a suitable conduit may be connected, as shown in Fig. 3. The bottom block 29 has two parallel sides 44 which are preferably ground to extreme accuracy.

The upper spacer block 3| may have formed therein a lubricant inlet bore 46 for the introduction of a lubricant to the surface of the rollers 32 and 3211. Also two tapped holes 41 may be formed therethrough for the reception of the jackscrews 36. The two side surfaces may be ground to an accurate dimension in a similar fashion to those of the lower spacer block, as in- I dicated at 48. A central cored hole 49 may be formed in the upper spacer block for the reception of an eye bolt 5|, best shown in Fig. 3. The four frame members are held together by the combination of keys and securing bolts. Accordingly the ground surfaces of the two frame members 28 and 28a may have key-ways 51 accurately milled in the lower portion thereof in a generally horizontal direction, and the lower spacer block 29 may have complementary keyways 52 formed therein. Ground keys 53 may be inserted in these two sets of key-ways and the keys 53 may be ground to fit. In a similar fashion, the upper portions of the frame members 28 and 28a have key-ways 54 accurately formed therein as by milling, and th upper spacer block 31 may have complementary key-ways 56. Ground keys 5] may fit these sets of key-ways and secure the upper spacer block between the two principal frame members. The entire frame is further secured together by means of bolts 58 (Figs. 2 and 3) that pass through apertures 59 formed in the frames 23 and 28a and which thread into tapped holes Si in the upper and lower spacer blocks 3| and 29, respectively.

The bottom surfaces of the principal frame members 23 and 28a are finished so that the frame may be accurately disposed on a planar surface and the side surfaces of the two frame members may be finished also for the attachment of retaining plates 62 held thereon by means of screws passing through th plates and into tapped holes in these finished edges. These retaining plates restrain the bearing blocks 33 from having an endwise movement.

From the foregoing description of the frame of each individual stand I2 it will be apparent that we have provided a muti-element frame wherein all parts thereof may be accurately and easily machined and ground. Accordingly the four elements 28, 23a, 29 and 3! may be cast in ferrous or non-ferrous metals, and thecontacting surfaces thereof may be milled and ground. These milling and grinding operations may take place upon conventional machines requiring little or no tooling for the setup, and accordingly may be inexpensively and quickly accomplished. The result is a frame having extreme accuracy in the portions wherein the bearing blocks 33 ride so that there can be no misalignment of the rollers 32 nor can there be any appreciable play in the positioning of these rollers. We have found that the stands made in accordance with our invention are not only more inexpensive to manufacture, but produce a much more satisfactory product than stands made in accordance with conventional practices.

-As mentioned previously, the preferred embodiment of our invention includes two shaving mechanisms 24 and 24a (Fig. 1), which mechanisms maybe substantially identical and a presently preferred form of which is shown in detail in Figs. 5 and 6. The shavers 24 may be secured to the stands I! or other suitable object by means of a plate 83 having an elongated aperture 64 therein through which the work material may pass. Secured to the bottom of the plate 83 by means of bolts 86 may be an elongated member 61 having a T-shaped cross section. A thin strip 68 of guide material such as hardwood may be applied to the top of the member 61, and an upper uide strip 68' may be yieldingly held adjacent thereto by means of studs ll threaded into the member 81, which studs have a spring 12 thereon compressed by a nut I3.

The material that is to be shaved may be guided edgewise by means of two rollers preferably in the form of roller bearing assemblies 14. The inner race of these bearings may rest upon, a washer 18 disposed upon projecting ears 11 of the member 81, and may be positioned along a horizontal plane by means of an eccentric enlargement 18 formed on the upper part of a hold-down bolt 18 having an enlarged head 8| that may be suitably apertured for the reception of jack bars for the rotation of the bolt. As noted particularly in Fig. 5, it will be seen that the ball bearing assemblies 14 which make contact with the edges of the strip passing through the shaver may be positioned in and out by rotation of the bolt 18 which moves the center of the eccentric section 18 in and out.

The material is drawn through the shaver by curately guided edgewise as just described. The edges of the material may be shaved by blades 82 each secured to a carriage 83 which is slidable on ways 84 in the form of two round rods that are secured to the member 81. A spring 86 may be reoived in a suitable recess in each carriage 83 and may be compressed against the member 61 to urge the carriages outwardly. The carriages may be adjusted inwardly against this spring pressure by means of hand wheels 81 that engage the carriages 83 and that have threaded shanks 88 that may be threaded into and out of the member 61. Thus rotation of the hand wheels 81 causes movement of the blades 82 toward or away from the workpiece passing through the shaver and accordingly may regulate the depth of cut of the blades.

The guides for guiding the material between the stands of our invention are shown generally at 88 in Fig. 1, and are shown in detail in Figs. 7, 8 and 9. The guides may include a lower guide member 8| having a wide channel cross section, the enter- 'the rollers of the subsequent stands and is acv ing mouth of which is flared outwardly as at 83 for centering the end of the strip that may be initially fed through the mill. An upper guide plate 88 may dovetail within the channel-shaped lower plate as shown in Fig. 9, leaving a thin elongated passage 84 between the two plates which is slightly thicker than the material that will pass through the mill, and may be just slightly wider than the material. The upper guide member 83 may be rigidly secured to an appropriate stand i2 by means of a cross bar 88 through which bolts 81 may pass to engage the upper guide member 83. The guides are preferably disposed on each side of each stand and accordingly each stand will employ two separate guides of a general construction shown in Figs. 7, 8 and 9.

As mentioned previously, our invention also includes an automatic shut-oi! device for the entire mill in the event that the strip of metal being reduced is broken or splintered. This control is based upon the fact that broken or splintered strip material will eventually become tangled and intermeshed in the mill so as to exert a considerable force upon the guides 80. Accordingly we hold the bottom guide member 8| to the stationary top guide member 83 by means of very thin screws 98 which may be easily broken or sheared by any unusual force. When the lower guide member 8| is thus broken away from the stationary top guide 83 it will contact the button of a microswitch 88 which may then be closed to complete a circuit.

As shown in Fig. 1, one or both guides of any one stand may be provided with a microswitch 88 to which may lead wires Hill which may pass through a conduit IM to the relay box I8 controlling the flow of current to the motors il.

When one of the microswitches 88 is closed, a circuit will be closed which will actuate a power relay in the relay box IE, thus opening the circult to the motors l7, causing the entire mill to cease operation. The attendant may then determine the trouble, remove the tangled broken material that caused the guide rupture, and again restart the mill.

The operation of the mill of our invention is in many respects similar to an ordinary mill. Referring to Figs. 5 and 6, the operator may first rotate the hand wheels 81 so that the blades'82 will permit the passage of a strip of initial width through each shaver 24 and 24a. If necessary, the hold-down bolt 18 may be rotated by inserting jack bars in its head 8| to rotate the guide assembly 14 sufficiently outward to permit the passage of the material. The jackscrews 36 may then be released, which permits the compression springs 34 to separate the bearing blocks 33 sufiiciently to permit passage of the initial starting material throughout the entire length of the mill Ill. The motor I! of the mill may then be energized and the jackscrews of the stand successively tightened until the desired thickness of the final product is obtained. The drive for this purpose is obtained from the sprocket wheels l6 that drive the chains M to drive the gear boxes l3, which in turn drive the rollers 32 through stub shafts 48 (Fig. 3) that are crosslink connected to the rollers 32 and 32a. The hand wheels 81 of the shavers 24'and 24a are then adjusted to the desired thickness so that a continuous shaving of material is obtained on each edgeat each shaver.

The adjustment operation of the stands 12 is effected by placing jack bars in the apertures of a as'oaaac 38 substantially simultaneously, which presses the bearing blocks 33 toward each other on each side of the stand.- The desired thickness of material may be determined by measuring the thickness of the emerging strip by a micrometer or otherwise.

The adjustment of the shavers may be explained with respect to Figs. and 6. The guiding of the edges of the material passing through the shavers is effected by rotating the ball bearing assemblies 14 into contact with the edges by rotating the bolt II by inserting the jack bars in its head 8|. The eccentric portion of the bolt moves the ball bearing assemblies 14 toward and away from the work. The cutting blades 82 are adjusted by rotating each hand wheel 81 so that the blade approaches the workpiece and cuts a desired thickness of shaving off of the guided strip. The rotation of the hand wheel causes its shoulder to bear against the carriage 83 due to threading ,of the bolt 88 into the member 61.

During normal operation of the mill, the guides 90 (Figs. 7, 8 and 9) act to accurately position the material going toward and away from each stand I2. In the event of breakage or splintering of the strip, however, the material will become tangled and exert force upon the guides, which will cause the breaking of the very small bolts 98 fastenin the two guides together. This breakage of the guides causes the lower guide 9! to contact the microswitch 99, completin a circuit therethrough which may actuate a relay in the relay box l9 (Fig. 1), stopping current to the entire mill.

It will be appreciated that the disclosed embodiment of our invention represents merely the presently preferred form thereof, and in no way constitutes a limitation of our invention. For example, it is possible to obtain satisfactory results with but a single shaving mechanism disposed either before the entire series of stands or between an initial pair of stands. The second shaving mechanism is desirable inasmuch as the starting material may be of a non-uniform thickness which may result in minute disconformities of the edge upon rolling, even though the edge was previously shaved. The accurate construction of our mill insures that there will be a uniform thickness to the metal after it has passed through one of the stands. Various forms of shaving mechanisms could easily be constructed without departing from the true spirit and scope of our invention, and it is contemplated that other precision edge forming mechanisms might also be considered as within the true spirit and scope of our invention. Nor do we limit ourselves to the precise construction of automatic stop for our mill, since it is obvious that various modifications in the guide structure and switch contacting mechanism could readily be made. Accordingly, therefore, we do not limit ourselves to the illustrated embodiment, nor otherwise, except by the terms of the following claims.

We claim:

1. The method of producing a thin strip of metal having a thickness which is a small fraction of its width and having smooth edges requiring no metal-finishing operation which comprises starting with a strip of material of approximately the desired finished width but of substantial thickness, removing from the marginal edges of the starting strip any irregularities extending transversely across said edges by making a shavmg out along said marginal edges by a cutting action which proceeds longitudinally along the edges of said strip, and then rolling said starting strip in a series of rolling steps to effect a substantial reduction in the thickness of the strip to a small fraction of the original starting strip thickness.

2. The method of producing a thin strip of metal having a thickness which is a small fraction of its width and having smooth edges requiring no metal-finishing operation which comprises starting with a strip of material of approximately the desired iinished width but or substantial thickness, removing from the marginal edges of the starting strip substantially all irregularities extending transversely across said edges by making a shaving out along said marginal edges by a cutting action which proceeds longitudinally along the edges of said strip, then rollin said starting strip in a series of rolling steps to effect a substantial reduction in the thickness of the strip to a small fraction oi the original startng strip thickness, and interposing REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 615,151 Ferguson Nov. 29, 1898 1,198,894 Cote Sept. 19, 1916 1,229,774 Moon June 12, 1917 1,360,001 Mathias Nov. 23, 1920 1,439,370 Lambert Dec. 19, 1922 1,499,656 Hein July 1, 1924 1,584,674 Smith May 11, 1926 1,650,607 Cook Nov. 29, 1927 1,686,398 Stoop Oct. 2, 1928 1,939,452 Kachei Dec. 12, 1933 2,012,849 Gardner et al. Aug. 27, 1935 2,116,980 Naish May 10, 1938 2,120,473 Sheperdson June 14, 1938 2,124,386 Malam July 19, 1938 2,150,248 Rosenbaum Mar. 14, 1939 2,210,921 Jones et al Aug. 13, 1940 2,236,743 Anderson Apr. 1. 1941 2,242,815 Darner Ma 20, 1941 2,247,050 Campbell June 24, 1941 2,318,732 Yoder May 11, 1943 2,371,671 Blount et al Mar. 20, 1945 FOREIGN PATENTS Number Country Date 304,479 Italy Jan. 9, 1933 OTHER REFERENCES The Making, Shaping and Treating of Steel, by C. B. Francis, 5th edition, pp. 712, 715, 1296, 1234, 1324 and 1325.

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