US3760677A

US3760677A - Shear for steel strip and the like

Info

Publication number: US3760677A
Application number: US00255004A
Authority: US
Inventors: A Campbell
Original assignee: Mesta Machine Co
Current assignee: MESTA ENGINEERING COMPANY APARTNERSHIP OF PA
Priority date: 1972-05-19
Filing date: 1972-05-19
Publication date: 1973-09-25
Anticipated expiration: 1990-09-25

Abstract

A floating shear arrangement comprises a first knife assembly mounted for movement toward a variable path of material to be cut, and a second knife assembly mounted for movement toward the material path and toward the first knife assembly. An arrangement is coupled to the knife assemblies for drawing the knife assemblies toward one another and toward the material path. The arrangement and the knife assemblies are disposed, such that one of the knife assemblies is moved initially into engagement with the material to establish a shearing location within a range of such shearing locations, and thereafter the other knife assembly is moved into shearing engagement with the material and the one knife assembly.

Description

1451 Sept. 25, 1973 United States Patent Campbell SHEAR FOR STEEL STRIP AND THE LIKE Primary ExaminerFrank T. Yost [75] Inventor. Allen B. Campbell, Pittsburgh, Pa. Atmmey D0nn J- Smith Mesta Machine Company, Pittsburgh, Pa.

May 19, 1972 Appl. No.: 255,004

[73] Assignee:

A floating shear arrangement comprises a first knife as- ABSTRACT [22] Filed:

sembly mounted for movement toward a variable path of material to be cut, and a second knife assembly mounted for movement toward the material path and toward the first knife assembly. An arrangement is coupled to the knife assemblies for drawing the knife assemblies toward one another and toward the material path. The arrangement and the knife assemblies are disposed, such that one of the knife assemblies is moved initially into engagement with the material to establish a shearing location within a range of such [56] References Cited UNITED STATES PATENTS shearing locations, and thereafter the other knife as- 83/600 X sembly is moved into shearing engagement with the material and the one knife assembly.

8 Claims, 3 Drawing Figures 83/600 X Petros et 83/557 .K m e m MC 376 5556 9999 1111 2605 0262 54 39 .9 9 O3 74 5 56, 2 2223 SHEAR FOR STEEL STRIP AND THE LIKE The present invention relates to a compact shear arrangement for a strip mill or the like and more particularly to a shear of the character described having floating shear components for adjustment to the angle of strip entry.

Throughout the steel industry strip shears and the like are employed in connection with rolling mills. Shearing of the continuous ribbon or strip in a rolling mill usually is done for one of a variety of reasons. For example, part of a strip coil containing damaged or offgauge material may have to be removed. Large coils are frequently cut into smaller coils for custom orders. The strip may have to be cut before entering the mill owing to cobbling or other equipment malfunction.

Present forms of rolling mill shears normally are located in the vicinity of the mill stand housing. Such locations, however, do not allow adequate access for inspection, servicing and maintenance of the shear. When employed as a cobble shear, conventional shears cause the strip to pile up in front of the shear at a nearly inaccessable location for removal. Previous shears utilize a relatively large number of component parts, with attendent manufacturing difficulties and excessive maintenance.

Most importantly, known forms of rolling mill shears are not capable of cutting the strip at a location in its natural path. That is to say prior shears do not adjust automatically to the particular path of the strip, which may be variable. For example a most accessible location for cutting the strip is prior to the tension bridle on the entry side of the mill. At this location the path of the strip is continuously changing, as the entry strip coil is paid out. However, conventional shears cannot be located here but located downstream of the tension bridle where the strip follows a more or less constant pass line. At this location the shear is relatively inaccessible as mentioned previously.

In accordance with my present invention l provide a floating shear for mill strip and the like which unexpectedly and almost instantaneously adjusts to a changing path of the moving strip, as the entry coil is paid out. This essentially automatic adjustment in the floating shear of the invention eliminates the need for a constant strip or material pass line. The shear of the invention is more compact with fewer parts which lessens manufacturing difficulties and reduces maintenance. The location of the novel shear at the mill entry bridle allows convenient access for inspection, servicing and maintenance. When employed as a cobble shear, the strip inevitably piling up in front of my novel shear is in a completely accessible location for easy removal.

I accomplish these desirably results and overcome the difficulties with the prior art by providing a floating shear arrangement comprising a first knife assembly mounted for movement toward a variable path of material to be cut, a second knife assembly mounted for movement toward said path and toward said first knife assembly, means coupled to said knife assemblies for drawing said knife assemblies toward one another and toward said path, said means and said knife assemblies being disposed such that one of said knife assemblies is moved initially into engagement with said material to establish a shearing location within a range of such shearing locations and thereafter the other of said knife assemblies is moved into shearing engagement with said material and said one knife assembly.

I also desirably provide a similar shear including means for mounting each of said knife assemblies for rotation about a common pivot structure.

I also desirably provide a similar shear wherein said moving means include a prime mover rigidly mounted on one of said knife assemblies and operatively connected to the other of said assemblies through pivoted linkage.

I also desirably provide a similar shear wherein said knife assemblies are disposed about said common pivot line such that said other knife assembly is subject to greater inertial forces at least to aid in inducing initial movement of said one knife assembly.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon during the forthcoming description of certain presently preferred embodiments of the invention and presently preferred methods of practicing the same.

In the accompanying drawings I have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same wherein:

FIG. 1 is a partial front elevational view of one form of strip shear arranged in accordance with my invention;

FIG. 2 is a partial top plan view of the shear as shown in FIG. 1 and is partially sectioned along reference line IIII of FIG. 3; and

FIG. 3 is a cross-sectional view of the shear as shown in FIG. 1 and taken along reference line III-III thereof.

Referring now more particularly to the drawings, the exemplary modification of the strip shear 10 illustrated therein comprises an upper knife assembly 12 and a lower knife assembly I4. The knife assemblies 12 14 are mounted for rotations about a common pivot line 36 at which is mounted in this example a pair of

stub shafts

16, 18. The shafts are stationarily mounted on

bridle frame plates

20, 22. Also mounted on the

bridle frame

20, 22 are entry tension rolls 24, 26, in the conventional fashion.

In the illustrated embodiment each of the

stub shafts

16 or 18 is provided with a

pair ofjournals

28, 30. The lower blade assembly 14 is mounted on the stub shaft journals 28 by connection to a pair of bearing housings 32 (FIGS. 1 and 2) such that the lower knife assembly pivots about the center line of the

stub shafts

16, 18. In like manner the upper blade assembly 12 is rotatably mounted on journals 30 of the

stub shafts

16, 18 by bearing housings 34 (FIG. 2). Thus, the knife assemblies 12, 14 are rotatably mounted on the same stub shafts for pivotal movement about the common center line 36 (FIGS. 1 and 2). Each of the bearing

housings

32, 34 include suitable and conventional bearing arrangements for anti-frictional purposes, as shown more particularly in the sectioned portions of FIG. 1.

A conventional shear blade 38 is mounted on the upper knife assembly 12, for example by means of mounting bolts 40. A mating knife blade 42 is similarly mounted on the lower knife assembly 14. When the upper and lower knife assemblies 12, 14 are pivoted together the

knife blades

38, 42 mate in the usual fashion to shear strip material or the like caught therebetween. The particular movements of the knife assemblies I2, 14 in making such shearing cuts are described more fully below.

As better shown in FIG. 3 the floating shear 10 of the invention is positioned on the entry

bridle frame members

20, 22 upstream rather than downstream of the entry of the strip between the lower tensioning roll 26 and idler roll 44. Although this represents the most accessible location for the shear of the invention, a problem is created for conventional shears in that the path of the incoming strip is continuously varying between a maximum angle approach denoted by arrow 46 and a minimum angle approach denoted by arrow 48. Such problem is created by the absence of a constant pass line 23 such as occurs downstream of the upper tension bridle roll 24. This problem is solved in a surprising manner by the present invention, in that the floating strip shear 10 can adjust automatically to the angle of strip approach (arrows 46, 48).

In furtherance of this purpose a pair of

operating cylinders

50, 52 or other suitable motive means are mounted on one of the

floating knife assemblies

12, 14, in this example on the lower knife assembly 14. The assembly 14 is provided with a pair of mounting plates 54, S6 for this purpose on which the

cylinders

50, 52 are flange-mounted respectively. Piston rods 58, 60 are pivotally connected to the upper knife assembly 12, for the purpose of drawing the

knife blades

38, 42 together for the shearing operation. A pair of the

cylinders

50, 52 are mounted as shown adjacent the ends of the lower knife assembly 14 for balanced application of operating forces. It will be understood however that a different number of operating cylinders can be employed depending upon the application of the invention.

In the arrangement shown, each of the piston rods 58, 60 terminates in a clevis 62 (FIGS. 1 and 3) which is in turn pivotally connected to pivoted link 64 in turn pivoted to the bearing housing 34 of the upper knife assembly 12. This double pivot arrangement permits the

operating cylinders

50, 52 and their pistons to adapt to the rotation of the

knife assemblies

12, 14, as the cylinders proper are rigidly joined to the lower knife assembly 14. It will be understood of course that various operating linkages can be made between the

knife assemblies

12, 14 in keeping with the broad concepts of the invention.

In operation, activation of the operating

cylinders

50, 52 retract the pivoted

linkages

62, 64 including piston rods 58, 60 to pivot the

knife assemblies

12, 14 toward one another upon the proper juxtaposition of the

knife blade

38, 42. The desired shearing action is attained, and a clean and complete cut is made on the strip that passes from pay out coil 66 or 66' at a varying angle (arrows 46, 48) between the upper and

lower knife assemblies

12, 14, i.e. through throat 70 of the floating shear 10. As mentioned previously as the entry coil 66 or 66' is paid out the strip approach angle to the shear l varies (arrows 46, 48). The particular limits of variation as shown in FIG. 3 are purely exemplary and in no way indicate actual or physical limitations, which will vary depending upon the structure of the shear 10, the initial size 66 and final size 66 of the entry coil, and its distance from the shear 10.

The most important consideration is the ability of the shear to adapt automatically to the continuously changing strip approach. Under normal operating conditions, the upper knife assembly will be pivoted under impetus of the one or

more operating cylinders

50, 52, until the upper blade 38 pivots into contact with the moving strip. The strip tension will resist further rotation of the upper knife assembly 12. During this initial movement of the upper knife assembly 12 into contact with the moving strip, the lower knife assembly 14, owing to its disposition about the common pivot line 36 (stub shafts l6, 18) will remain stationary under influence of gravity or other inertial forces. However, following the initial movement of the upper knife assembly 12 into contact with the moving strip and its restraint thereby, the lower knife assembly 14 then pivots toward the strip and the upper knife assembly 12 retained thereby to make the shearing cut.

Inasmuch as the lower knife assembly 14 remains more or less motionless until the upper knife assembly essentially completes its movement to the variable shearing location, the moving components of the shear 10 always adjust themselves quickly and automatically to the particular angle of strip approach when the shearing cut is made. Although described as discrete movements of the upper and

lower knife assemblies

12, 14 it is to be understood that the prepositioning of the upper knife assembly 12 and the subsequent shearing motion of the lower knife assembly 14 are produced by a single operational movement of the operating

cylinders

50, 52, including their piston rods 58, 60 and associated pivoted linkages.

It will be noted also that the amount of preliminary positioning movement of the upper knife assembly 12 will vary from almost nil to almost the full extent of the throat opening of the shear 10 depending on whether the strip approach is at or near the maximum angle (arrow 46) or the minimum angle (arrow 48) respectively, as dictated, of course, by structural limitations in a given embodiment. In any event, the strip is quickly and efficiently sheared irrespective of the particular point in the rotative paths of the blade assemblies l2, 14 at which the

shear blades

38, 42 mate for shearing action.

Desirably stop means 72, 74 are disposed on at least one of the

frame members

20, 22 for determining respectively the initial or starting positions of the blade assemblies 12, 14 (FIG. 3). Location of the stop means 72, 74 is determined by the desired maximum throat opening 70 between the

shear blades

38, 42. The maximum throat opening 70 will, of course, be determined by the range of strip approaches or path variations (arrows 46, 48) in a given application of the invention.

From the foregoing it will be seen that a novel and efficient shear for steel strip and the like has been described herein. The shear is capable of making cuts in the strip at an advantageously accessible location, in contrast to prior apparatus. The described apparatus is susceptible of semiautomatic or completely automated operation as desired. The descriptive and illustrative materials employed herein, therefore, are utilized for purposes of exemplifying the invention and not in limitation thereof. Numerous modifications of the invention will occur to those skilled in the art without departing from the spirit and scope of the invention. It is to be understood that certain features of the invention can be used to advantage without a corresponding use of other features thereof.

I claim:

l. A floating shear arrangement comprising a first knife assembly mounted for movement toward a variable path of material to be cut, a second knife assembly mounted for movement toward said path and toward said first knife assembly, means coupled to said knife assemblies for drawing said knife assemblies toward one another and toward said path, said means and said knife assemblies being disposed such that one of said knife assemblies is moved initially into engagement with said material to establish a shearing location within a range of such shearing locations and thereafter the other of said knife assemblies is moved into shearing engagement with said material and said one knife assembly.

2. The combination according to claim 1 including means for mounting each of said knife assemblies for rotation about a common pivot structure.

3. The combination according to claim 2 wherein said moving means include a prime mover rigidly mounted on one of said knife assemblies and operatively connected to the other of said assemblies through pivoted linkage.

4. The combination according to claim 2 wherein said pivot structure includes a pair of opposed stub shafts, and said blade assemblies are mounted respectively on bearing arrangements disposed longitudinally of said shafts.

5. The combination according to claim 2 wherein stop means are disposed adjacent said pivot line for engagement by said knife assemblies to determine the maximum throat opening thereof.

6. The combination according to claim 2 wherein said knife assemblies are disposed about said common pivot line such that said other knifeassembly is subject to greater inertial forces at least to aid in inducing initial movement of said one knife assembly.

7. The combination according to claim 1 wherein said other knife assembly is subjected to greater inertial forces relative to said one knife assembly at least to aid in inducing initial movement of said one knife assembly.

8. The combination according to claim 7 wherein said other knife assembly is disposed at a lower elevation than that of said one knife assembly such that said other assembly is subjected to greater gravitational forces for the purpose stated.

Claims

1. A floating shear arrangement comprising a first knife assembly mounted for movement toward a variable path of material to be cut, a second knife assembly mounted for movement toward said path and toward said first knife assembly, means coupled to said knife assemblies for drawing said knife assemblies toward one another and toward said path, said means and said knife assemblies being disposed such that one of said knife assemblies is moved initially into engagement with said material to establish a shearing location within a range of such shearing locations and thereafter the other of said knife assemblies is moved into shearing engagement with said material and said one knife assembly.

6. The combination according to claim 2 wherein said knife assemblies are disposed about said common pivot line such that said other knife assembly is subject to greater inertial forces at least to aid in inducing initial movement of said one knife assembly.