US3492853A

US3492853A - Method and apparatus for shearing rolled metal blanks

Info

Publication number: US3492853A
Authority: US
Inventors: John Gross
Original assignee: EW Bliss Co Inc
Current assignee: BLISS-SALEM Inc A CORP OF
Priority date: 1967-09-06
Filing date: 1967-09-06
Publication date: 1970-02-03
Anticipated expiration: 1987-02-03
Also published as: US3565309A

Description

Feb. 3,1970 .Lnoss 3,

METHOD AND APPARATUS FOR SHEARING ROLLED METAL BLANKS Filed Sept. 6, 1967 o 2 Sheets-Sheet 1 l2 r I/ A Fl G. l

2 II I DIRECTION OF ROLLING I2 DIRECTION OF ROLLING 32 INVENTOR.

JOHN GROSS Y fl lw m, Wham, 22 Body ATTORNEYS Feb. 3, 1970 J. GROSS 3,492,853

' METHOD AND APPARATUS FOR SHEARING ROLLED METAL BLANKS Filed Sept. 6, 1967 2 Sheets-Sheet 2 FIG. 2A 37 Fl G. 4A

I II I FIG. 48 m FIG. 5A

FIG. 5B

INVENTOR. JOHN GROSS ATTORNEYS BY M WI /M,

United States Patent ABSTRACT or THEDISCLOSURE An improved method tand apparatus for shearing hot rolled-metal blanks in which. shear bladeshavinga par ticular' shape are used to shear the metal blank to produoe a tapering transverse edge configuration having a longitudinally extending central portion relative to the top and bottom surfaces of theblank therebyto minimize laminating of the sides in subsequent rolling operations.

This'invention relates to the art of rolling metal blanks and, more particularly, is directed to an improved method and apparatus for shearing rolled metal blanks during the rolling process.

The present invention is particularly adapted for reducing the effect of creep or uneven fiber elongation encountered in hot rolling of aluminum blanks into thin stripsand it will be discussed with particular reference thereto; however, the invention hasbroader applications and is applicable to any process in which metal isbeing reduced in cross. section and lengthened through mechanical working.

Aluminum normally is cast in cakes or blanks up to approximately 20 inches thick and these cakes arehot rolled to form strips by means of a. reversing hot mill normally followed by several mill stands in tandem. The aluminum cakes, as cast, usuallyhavetransverse end surfaces which are perpendicular to the-top and bottom surfaces of the cake. As the cake is passed through the rolling mill, the cake. is progressively reduced in thickness in conventional manner. However, it normally occurs in the hot rolling of aluminum that the surfaces of the cake in engagement with the rolls tend to elongate more thanthe' interior of the cake. 'In other words, the outer fibers ofthe cake elongate more than the inner fibers which produces a lapping or laminated effect at the ends of the resulting sheets. Moreover, with some types of aluminum, these laminated portions tend to spread apart at their outer ends and this condition is known as alligatoring.

*To eliminate the laminated sections aswell as the alligatorpo'rtion, the cakes of aluminum. aresheared periodically. The priorart has conventionally sheared the faces of the cake. Asfurther rolling of the aluminum occurs, additionalla-minating and alligatoring of the sheet occurs, thereby necessitating additional shearing of the cake.

The present invention contemplates minimizing the effects'ofuneven fiber elongation in a metal rolling operation by shearing the blank to produce 'a configuration which'provides for uneven fiber elongation thereby minimizing the undesirable laminating and alligatoring.

In accordance with the present invention, there is provided an improved method of rolling a metal blank which includes the step of shearing the blank to produce a tapered transverse edge configuration having a longitudinally extending central portion relative to the top and 3,492,853 Patented Feb. 3, 1970 2 bottom surfaces of the blank with the remaining portion of the edge tapering rearwardly of the blank.

In accordance with another aspect of the invention, there is provided an improved shearing device for minimizlng laminating and alligatoring of rolled metal blanks. The shearing device comprises two shearing blades mounted, in opposed relationship to one another and means to reciprocate at least one of the blades thereby to shear the metal blanks placed between the blades. Each blade has opposed shearing faces which define therebetweien0an included anglewhich is within the range of 30 to 2 It is, a primary object of this invention to provide a method and apparatus for reducing theefiects of 1aminating and alligatoring ofvmetallblanks during a rolling operation.

. A further object of this invention isto provide novel shearing apparatus which is operative to shear a metal blank in a manner which reduces the effects of laminating and alligatoring in subsequent rolling operations.

Another object of this invention is to provide a method of shearing a rolled metal blank which includes the step of shearing the metal blank to form a forwardly tapering transverse edge configuration.

These and other objects and advantages willbecome more apparent from the following description when taken in connection with the accompanying drawings in which like reference numerals indicate like parts in the various views.

FIGURE 1 illustrates in sequential steps'A through F the laminating and alligatoring of a metal blank as it progresses through the rolling operation.

FIGURE 2 is a perspective view illustrating schematically a metal blank being sheared in accordance with the present invention.

FIGURE 2A is a side elevation view of the sheared end of the metal blank when sheared as shown in FIG- URE 2.

FIGURE 3 is a side elevation view illustrating the shearing ofa metal blank by an alternative form of shear blades.

FIGURE 3A is a side elevation view of the metal blank after the shearing operation of FIGURE 3.

FIGURE 4 is a bottom plan view of a further alternate embodiment of a shearing blade.

FIGURE 4A is a top plan view of a metal blank sheared in accordance with the shearing blade of FIG- URE 4. 1

FIGURE 4B is a side elevation view of the metal blank of FIGURE 4A.

FIGURE 5 is a bottom planview of another alternate embodiment of the shearing blade.

FIGURE 5A is a top plan view of a metal blank sheared with the blade of FIGURE 5.

' FIGURE 5B is aside elevation view of themetal blank of FIGURE 5A.

FIGURE 6 illustrates schematically the shearing operation at an intermediate locationinthe rolling process.

Referring now to FIGURE 1, there'is illustrated schematically the various stages through which a metal blank, generally indicated by the reference numeral 10, passes during a rolling process.Stage' A shows the metal blank prior to rolling and the blank includes opposed top and

bottom surfaces

12 and 14

transverse edge portions

15, 16 It s'hould be noted-that the

edge portions

15, 16 are perpendicular to the opposed'hori'zontal upper and

lower surfaces

12 and 14. i

The stages B through F illustrate the effect of the rolling operation on the metal blank as it is passed through a reversing rolling mill. Thus, stage B shows the blank after the initial rolling operations and it is to be noted that outer fibers of the blank comprising the top and

bottom surfaces

12 and 14 have begun to be elongated while the inner portion of the blank has elongated to a lesser extent. The result is the formation of top and

bottom crests

18 and 20 which are beginning to overlap the central portion 19 of the edge 16. The development of the

crests

18 and 20 relative to the central portion 19 becomes more pronounced as the rolling process continues as is apparent in stage C and ultimately results in the 4 elimination of the valley 19 as the

crests

18 and 20 are further elongated and come together to form a lamination. It should be noted in stage D that the uneven elongation of the metal blank occurs even in the crest portion of the blank so that the extreme outer fibers of the

crests

18 and 20 tend to elongate more than the inner fibers of the crest.

In stage E of the rolling operation, the laminating of the material has become more pronounced and defined top and

bottom layers

22 and 24 have now been formed. These relatively thin top and bottom layers have a tendency to alligator or roll up at their leading edges 26 as is apparent in stage E. The alligatoring effect becomes more pronounced as the rolling process continues and the

layers

22 and 24 tend to separate at the extreme outer ends to form an opened mouth which renders it extremely difiicult to feed the blank into the next rolling station.

In view of the tendency to laminate and alligator, the metal blanks normally are sheared at intermediate stages in the rolling operation and also prior to entry into the tandem hot mill. Traditionally, this shearing of the metal blank has simply entailed removing the laminated portion of the blank to form a transverse edge which is per pendicular to the upper and lower surfaces of the blank. In other words, the shearing operation simply produces an end on the metal blank which is substantially the same as the blank had when it was first formed and further reduction of the blank after the shearing operation simply results in the formation of the same laminated end as previously described.

In accordance with this invention, it is contemplated that the shearing operation will be designed to minimize the subsequent tendency of the metal blank to laminate and alligator. This is accomplished by shearing the metal blank in a particular configuration using specially designed shear blades. Thus, referring to FIGURE 2, opposed

shear blades

30, 32 are provided with the shear blades having a length sufiicient to extend across the width of the metal blank. Both shear blades are identical in the construction of their cutting faces. The cutting faces of the shear blades include opposed beveled side faces or surfaces 33, 34 which converge to define a cutting edge 35. The

surfaces

33, 34 define therebetween an included angle which is preferably in the range of 30 to 120. With each of the

shear blades

30, 32 having an included angle within this range, the resultant cut of the metal blank produces an angle on the leading edge of the sheared blank which has an apex angle in the range of approximately 60 to 150. It is contemplated that the

shearing blades

30, 32 will be restrained in their movement toward each other so that the two blades do not come into contact at the completion of the shearing operation. This separation of the

shear blades

30, 32 results in a small flat section 36 which is defined by a line drawn between the cutting edges 35 of the two blades. The separation of the metal is ultimately accomplished by the wedging action of the

blades

30, 32 since complete penetration of the metal is prevented.

FIGURE 2A illustrates the leading edge of a freshly severed metal blank. This leading edge now includes beveled upper and lower leading

edges

37, 38 terminating in the above described narrow fiat section 36. With this arrangement, the feeding of the metal blank into the rolls of a mill is greatly facilitated. More importantly, however, the tapered leading edge surfaces 37, 38 provide for growth of the outer fibers of the upper and

lower surfaces

12, 14 of the metal blank as the blank is passed through the rolling operation. Thus, as the outer fibers tend to elongate, the crest and valley configuration described above does not occur for a considerable period of time since the growth of the outer fibers along the

surfaces

37, 38 merely tend to return the blank to a condition wherein the leading edge is perpendicular to the upper and lower surfaces. As a result, such lamination as occurs is compensated for and the tendency to alligator is significantly diminished.

Referring now to FIGURES 3 and 3A, there is illustrated an alternate form of a cutting blade. The cutting blades 40 are similar in configuration to the cutting blades of FIGURE 2 in that they do employ opposed side faces 42, 43 which converge to a cutting edge 44. However, the side faces 42, 43 each have a double beveled configuration with a secondary

beveled surface

42a and 43a immediately adjacent the tip so that the included angle between the

surfaces

42a, 43a is larger than the included angle between the

surfaces

42, 43. The use of a double bevel as shown in FIGURE 3 provides relief for the shearing blades as they penetrate the work blank thereby reducing the amount of force required to shear the metal blank. FIGURE 3A illustrates the resultant sheared metal blank which has a correspondingly double

beveled surface

46, 47 tapering to a central portion having a flat section 48.

FIGURES 4 and 5 illustrate further alternate embodiments of the shear blades whereby a triangular or a curved shape may be given to the forward edge portion of the metal blank. Referring first to FIGURE 4, the shear blade 50 is shown in bottom plan view and includes a cutting edge 52 with opposed beveled side faces 53, 54 converging to the cutting edge. However, the shear blade 50 is made in two

pieces

50a, 50b with the two pieces being angularly disposed to form a V-shape configuration. The blades 50 thus make the beveled cut of the metal blank along an angle extending across the metal blank as shown in FIGURE 4A.

FIGURE 5 shows a further modification which is similar to FIGURE 4 in that the shear blade may be made in two parts but, instead of an abrupt angle between the two

pieces

60a, 60b of the shear blade, the blade is curved to provide the beveled cut on the metal blank across a gently curving line as shown in FIGURE 5A. The

blades

50 and 60 are similar to

blades

30, 32 in that the side faces have a continuously beveled surface. It is to be understood that

blades

50, 60 might also employ the double beveled configuration of blade 40 shown in FIGURE 3.

The above described shear blades may be employed in any type of press or other mechanical means whereby at least one of the shear blades is moved toward the other to cause penetration of the metal blank. schematically illustrated in FIGURE 6 is such an arrangement in which a plurality of rolls are illustrated with the metal blank 10 passing through the rolls. The shearing apparatus comprises the

shear blades

30, 32 with the shear blade 32 being fixedly supported in a frame 74. The upper shear blade 30 is mounted for reciprocation between guides 76 along a line coaxial with the shear blade 32. Some form of ram or platen 78 may be used to reciprocate the shear blade 30 with appropriate means to limit the movement of the shear blade 30 toward the shear blade 32. Any appropriate mechanism may be employed to accomplish this purpose, such as a stop mounted on the frame, orother limiting means which limit the movement of the ram 78. For purposes of illustration, a stop 80 has been shown on the guide mechanism 76.

It is to be appreciated that the arrangement shown in FIGURE 6 is purely for purposes of illustration and is not to be construed as limiting since other arrangements for mounting and operating the shear blades are entirely possible. For example the shear blades may be operated without the necessity of guides 76 or both of the

shear blades

30, 32 may be mounted for reciprocation. The

r 5 6 essence of the arrangement is the particular configuration and lower surfaces have elongated beyond the for of the shear blades together with some provision for reward edge of the blank, and ciprocating at least one of the shear blades and means for repeating the shearing operation. limiting the amount of reciprocation to prevent contact 2. A metho of claim 1 wherein the shearing 0f the between the two shear blades when the workpiece is metal blank comprises the p of; sevemi passing cutting blades partially through the metal blank Having thus described my invention 1 claim; from opposed positions on the top and bottom sur- 1. A method of rolling a metal blank comprising the faces of the blanksteps of:

passing the metal blank through a plurality of rolls to 10 References Clted decrease the thickness and increase the length there- UNITED STATES PATENTS of until the upper and lower surfaces of the blanks 1,525,456 2 /1925 L t h t 1 72-203 adjacent the transverse edge have elongated and over- 2,057,928 10/1936 Stahl 83---51 lap the central portion of the edge, 15 2,061,659 11/1936 Iversen 72-203 shearing the metal blank adjacent the transverse edge 3,416,347 12/1968 Walsh et a1. 83-51 to form a generally rearwardly tapering upper and lower surface at the transverse edge of the blank, MILTON MEHR Pnmary Exammer inserting the tapered transverse edge in a roll and con- U.S. Cl. X.R.

tinuing the rolling process until the tapered upper 83-51