US2007533A - Method and apparatus for shearing - Google Patents

Description

July 9, 1935; 4 L. NERsEN 2,007,533

METHOD AND APPARATUS FOR SHEARING Filed July 23, 1952 s Sheets-Sheet 1 July 9, 1935.

L. IVERSEN METHOD AND APPARATUS FOR SHEARING s Shets-Sheet 2 Filed July 23, 1932 July 9, 1935. NERSEN 2,007,533

METHOD AND APPARATUS FOR SHEARING Filed July 25. 1932 s Sheets-Sheet 3 QMMQQ Patented July 9, 1935 PATENT OFFICE 2,007,533 ME'rnon AND APPARATUS FOR SHEARING Lorenz Iversen, Pittsburgh, Pa., assignor to Mesta Machine Company, Homestead, Pa., a corporation of Pennsylvania Application July 23, 1932, Serial No. 624,174

'1 Claims. (01. 164 68) The present invention relates broadly to the shearing of material, and more particularly to an improved method and apparatus efiective for shearing material in motion. Claims to certain subject matter common to this disclosure and that of my copending application Serial No. 628,878 filed August 15, 1932, for Feeding and shearing apparatus, appear in the latter.

With the increasing use of high speed continuous mills such as utilized for the production, for example, of strip material, the problem of making satisfactory disposition of the product as fast as it is rolled, or atleast of putting such 7 product into such form that it may be conterial.

veniently shipped or stored in a more or less semi-finished condition ready for subsequent finishing operations is becoming increasingly important. At the present time, there are several methods in general use for handling such a product.

In the case of strip, for example, it may be coiled as it is delivered from the mill, or it may be sheared into lengths by a flying shear located directly behind the mill andpiled hot, or

it may be run onto a cooling bed of suitable design and sheared, after sufiicient cooling, by plate or bar shears of the conventional or stationary type. Each of these methods has certain useful applications as well as certain disadvantages and limitations.

Hot rolled coiled material is well adapted for subsequent cold rolling or other finishing operations where the material may be readily fed to the finishing or forming machines from the coils. It is, however, not so well adapted for the production of fiat sheets, inasmuch as the materialmust be uncoiled, leveled and sheared after the coils have been cooled sufliciently to permit the performance of these steps. Hot shearing at the mill with hot piling is'suitable for certain classes of product, but for others it frequently leaves much to be desired in the way of accuracy, flatness and grain structure. Cold shearing' from a cooling bed by means of stationary plate or bar shears has serious limitations in speed andeconomy. Not being continuous in operation, itis usually not well adapted to serving the requirements of a high speed continuous mill.

The present invention relates to a method and apparatus for the continuous leveling and shearing of accurate lengths of metal or other ma- In the case of metal, the desired result is accomplished by taking the metal directly from a roller table or other cooling bed which bed lengths for example, after it has been delivered from the mill, and leveling and shearing such material to desired lengths in a continuous operation. As practiced in accordance with the 10 disclosure of the present application, it over--' comes disadvantages of the character above referred to and obviates the limitations with respect to fiat sheared material.

Certain of the'objects of the present invention 15 are to accomplish a leveling and shearing in a substantially continuous manner at a speed which is greater than customary in the art and such as to keep pace with the production of a present day highspeed continuous mill. It also pro- 20 duces flat sheets accurately sheared to the desired predetermined length, and includes means for easily and conveniently varying the lengths within predetermined limits. It also makes suitable provision for cropping any desired predeter- 25 mined length from the front or leading end of the strip or other shape, regardless of the length of the subsequent regular or uniform cuts. It also provides means for conveniently indicating the length which the equipment is 30 set to out, together with means insuring greater accuracy of shearing without undesirable marking of the material.

In the accompanying drawings there is illustrated more or less diagrammatically, a preferred 35 embodiment of the present invention. In the drawings: a

Figure 1 is a top plan view of one form of apparatus constructed in accordance with the present invention;

Figure 2 is a longitudinal sectional view, partly in elevation, along the line 11-11 of Figure 1;

Figure 3 is a detail view, on an enlarged scale, partly section and partly in plan, of a form of limit switch utilized in. accordance with the present invention;

Figure 4 is a side elevational view with the limit switch illustrated in Figure 3 shown in section; and

Figure 5 is an end elevational view of the limit switch of Figures 3 and 4.

Referring more particularly to Figure l of the drawings, there is illustrated a portion of a runout table 2 of the roller type adapted to feed material from a continuous mill, not shown, in the direction indicated by the arrow A. At a predetermined point in its travel, the material comes into an alinement with a cooling bed 3 across which it may be conveyed in any desired manner as by suitable transfer chains 4, as well understood in the art. The cooling bed may be of any standard construction and of such dimensions and such speed of operation as to insure cooling of the material to the desired temperature at the time it leaves the end of the cooling bed. From the cooling bed the material may be transferred in any desired manner to a roller table 5 comprising a series of rollers, any number of which may be positively driven through suitable gearing from a line shaft 6, the direction of travel of the rolls being such as to feed the material in the direction indicated by the arrow B.

In line with the roller table 5 is a piler l of any desired construction. Intermediate roller table and piler is a pair of pinch rolls 8, a roller leveler 9 and a rotary shear I 0, these pieces of equipment being so located as to be engaged by the material in the order mentioned.

Inasmuch as the shear constitutes one of the more important parts of the equipment, it will first be described in detail. The shear is preferably of the rotary type comprising an upper rotor II and a lower rotor l2, each of which carries a shear blade M. The rotors are geared together after the usual manner in shears of this type in the ratio of the pitch diameters of the rotating heads or rotors so that the blades come together at recurrent intervals.

In accordance with the present invention, the gear ratio is .such as to effect a condition of operation in which if the rotation of the rotor I2 is considered as unity, the rotation of the rotor II will be an even multiple of unity. This may be accomplished, for example, by a 2 to 1, 3 to 1, a 4 to 1 ratio or the like. With such a construction, and assuming a 2 to 1 ratio, a shearing operation will be accomplished once during each rotation of the rotor l2, this requiring two complete revolutions of the rotor ll. Cooperating with the rotors II and I2 is a suitable feed-in table l5 along wihch the material is adapted to travel, the surface of the feed-in table preferably being slightly convcxed or arched upwardly, and having its discharge portion substantially tangent to the surface of the rotor I2, whereby the material leaving the table will be supported by the body of the rotor l2.

In this position it will normally lie well below the point of maximum projection of the blade M in the rotor ll so that regardless of the number of idle revolutions of the rotor. I I, the blade carried thereby will not be effective for marking or marring the material. At the shearing period,

the blade H in the lower rotor will lift the material vertically into such a position that the blade in the upper rotor will become effective thereon, thus enabling the desired shearing to be accomplished. The important consideration in a shear of this type is that a out be made each time the blade in the lower head rotates to the cutting point and lifts the material. At all other times the material is carried through the shear at such a level that it is cleared by the rotating upper blade without any danger of marking the material. The same result is thus accomplished as if both rotors were of the same diameter as the larger rotor, with the advantage, however, that the shear is much less bulky and the rotative speed of the small rotor is usually better .adapted without a high ratio gear reduction to the most the suitable speed of a driving motor Hi. This driving motor is shown as interconnected to the shear through a suitable gear train I"! as well understood in the art.

A portion of the gear train ll includes a shaft l8 preferably connected through a flexible coupling l9 to a displacement hydraulic pump 20 of any suitable type, the displacement of which is determined by a suitable adjustment 2!. The function of the hydraulic pump is to provide a convenient positive variable speed transmission between the shear drive and the roller leveler and pinch rolls. This is effected by connecting the hydraulic pump through suitable pipes 22 to a hydraulic motor 23, whereby the hydraulic motor will be driven by the hydraulic pump at a speed dependent upon and determined by the displacement of the pump. Inasmuch as a pump of this character, the constructional and operating characteristics of which are well known to those skilled in the art, may be adjusted to give an almost infinitesimal increase or decrease in the displacement at the pleasure of the operator, it provides extremely sensitive means for imparting a variable speed drive to the motor 23. This motor is in turn connected through suitable flexible couplings 24 to a shaft 25 projecting from a gear box 26. The hydraulic drive described above is also disclosed and claimed in my United States Patent No. 2,004,871, granted June 11, 1935.

Projecting from the gear drive box 26 are shafts 21 connected through suitable flexible couplings 28 to'pinion shafts 29 effective for driving a train of pinions 30. This pinion train is in turn effective through universal spindles 3| for driving the leveler rolls 32 of the roller leveler 9.

Also projecting from the gear drive box 26 is a shaft 33 suitably connected to the pinch rolls 8 for driving the same.

While I have herein referred to an hydraulic transmission, it will be apparent to those skilled in the art that other forms of variable speed transmissions such as belt and cone pulleys, the so-called Reeves transmission or mechanical tumbler gears such as provided in the head stocks of lathes and other machine tools and as shown in my co-pending application Serial No. 378,205, filed July 15, 1929, might be utilized if desired. The important characteristic of an hydraulic drive, however, is that it is positive and yet enables the speed ratio to be easily and conveniently changed, not in successive increments or steps of predetermined fixed differences, but continuously by infinitely small graduations as the displacement of the pump is varied.

The particular arrangement of parts herein described is extremely advantageous in that the pinch rolls provide effective means for feeding material from the roller table 5 into the roller leveler. The roller leveler in turn, after the material has been engaged thereby, cooperates with the pinch rolls, by reason of the large area of contact afforded by the leveler, in preventing slipping of the material in the pinch rolls. Heretofore it has been found that due to the undulations, inequalities, surface coatings, and other characteristics of material such as pinch rolls are frequently called upon to handle, the feeding speed of the material when fed entirely by pinch rolls has not always been exactly uniform, or exactly equal to the peripheral speed of the pinch rolls. This difference in speed and uniformity has obviously represented slip between the material and the pinch rolls which has not only Cil tended to mar the material, but has produced such a variable feeding movement of the material as 'to result in variations in the lengths sheared. By combining pinch rolls with a roller leveler, however, the possibility of slippage is prevented and the feeding speed of travel of the material corresponds exactly to the peripheral speed of the pinch rolls.

The roller leveler in this combination is further of importance in that it levels the material and passes it to the shears in leveled condition. In such condition each surface of the material represents a substantially truly flat surface and makes it possible to feed the material at such a height with respect to the shear blade in the upper rotor as to prevent marring of the material by such shear blade. With uneven material, such a feeding characteristic is not possible.

If the speeds of the several units are so proportioned and adjusted that the strip is fed to the shear by the pinch rolls and leveler at the same speed as the pitch line speed of the shear knives, the length cut by the shears will be equal to the pitch circumference of the larger head in the case of a ratio such as previously described, where the large head carries but one knife.- If the strip is fed at a relatively faster rate, longer lengths will be cut, while if it is fed at a relatively slower rate, shorter lengths will be the result. The combination of a positive variable speed drive for the leveler and pinch rolls interconnected with the shear drive so as to maintain a definite but adjustable speed relation between the two, provides means for easily and conveniently varying the length cut within the predetermined limits prescribed by the design of the apparatus.

The combination of the pinch rolls and leveler serving not only as feeding means for the material but as straightening means therefor, forms the most effective means for a combination of this character, in that a movement of the strip or other material exactly conforming to the peripheral speed of the rolls in engagement therewith is insured. Furthermore, such a method of continuous leveling and shearing in a single opera- 7 tion enables strip or other material to be taken from a roller table or cooling bed at the rate at which it is delivered from a high production continuous mill without interruption or intervening storage or delay other than that necessary to permit the desired cooling while that material is traversing the cooling bed. After leaving the shear, the sheared lengths are ready for inspection, so that it is possible to make shipment of material directly from the shear.

The present apparatus is also of such nature as to make possible the cropping of the leading end of the material. This may be effected by utilizing the roller table to bring the material against and into the bite of the pinch rolls so that the slightest movement of the pinch rolls will engage the front end of the material. The running speed of the table is preferably adjusted to the speed of the pinch rolls and the speed of the leveler. The pinch rolls, leveler and shear being driven by a common motor, are accelerated together -(by the closing of a manual switch, for example) from a predetermined initial position, so that by the time the knives have rotated to their cutting position the front end of the material has run through the shear to the extent required to effect the desired length of crop. After the front end has been cropped, the shear, leveler, pinch rolls and table will continue to run, the shear cutting uniform lengths until the entire length of the material has been leveled and sheared.

In order to insure a condition of operation such that the cropping will be uniformly effected, it is necessary to stop the shears with the knives in predetermined position. This is conveniently accomplished by the provision of a limit switch 36', preferably of the drum type, which stops the shear in the correct position to cut the desired length of crop from the front end of the following piece of material.

It is evident that the setting of the limit switch will determine the lengthof crop end out, since the peripheral travel of the shear knives from the starting position to the position for cutting the front crop must occur while the material is travelling from the pinch rolls to the cropping position. This distance of travel is constant, being determined by the design of the apparatus, while the peripheral travel of the shear knives is variable and depends upon the speed relation between the shear and the feeding means and hencev upon the length being cut. Provision must therefore be made for changing the limit switch setting in accordance with the desired crop length. As indicated in Figure 1, the limit switch is so positioned as to be driven by one of the shear heads or rotors whereby it is rotated at a speed which always bears a definite relation to the speed of operation of the shear itself.

Since the ratio between the speed of the shear and that of the'pinch rolls may be varied by means of the hydraulic drive, it willbe evident that it is necessary to compensate the adjustment of the limit switch to maintain the desired crop length, if the speed ratio is changed to vary the length of pieces out after cropping. If no compensating adjustment were made, a change in the ratio of the speeds of the shear and the pinch rolls would result in the cropping of a longer or shorter length than that for which the limit switch is initially adjusted. If it is assumed that the limit switch is adjusted to crop a certain length L, if the'hydraulic drive is adjusted to increase the length of pieces out after cropping, the length of the crop will be correspondingly increased. To prevent this, a compensating adjustment of the limit switch is made.

In Figures 3, 4 and 5 of the drawings the construction of one type of limit switch is illustrated in detail. As illustrated in these figures, the limit switch may include a rotating drum 36 carried by a shaft 3? to which is secured a disk 33. The disk adjacent its periphery carries anannular ring 3% provided with internal gear teeth meshing with planet gears fit on stub shafts ill secured in a suitable frame t2. Journaled within this frame is a shaft 33 by means of which the limit switch is connected to the rotary shears. The shaft d3 carries a sun gear M meshing with the planet or idler gears M. By'reason of this construction, rotation of the sun gear it will efiect rotation of the planet gears M, which rotation will be transmitted to the internal gear and thence to the contact drum 3E1.

The ratio between the sun gear and the internal gear is preferably such that the limit The desired adjustment having been effected, the parts are held in adjusted position and against further relative movement by a locking screw 46. This locking screw is carried by a stationary housing 4'! and is adapted to engage any one of a series of locking openings 48 in the periphery of the frame 42.

It will be apparent to those skilled in the art that by adjusting the frame 42 circumferentially in one direction or the other, the limit switch drum may be advanced or retarded in its relation to the shear knives to thereby change the time at which the limit switch will become eifective. I prefer to utilize this adjustment of the limit switch to compensate for changes in the ratio of the speeds of the shear and pinch rolls, to maintain constantly a predetermined length of crop. The frame 42 will preferably be provided with a suitable index or scale 49 corresponding to the range of length cut so that such frame may conveniently be set to a suitable pointer or index for any length being cut so as to maintain a constant length of front crop, regardless of the ratio be-' tween the speed of the shear and the pinch rolls. In like manner, the hand adjustment 2| for the hydraulic pump may be provided with a similar scale 50 to indicate the proper setting for the length to be cut.

The limit switch drum 36 carries a contact strip 5| which is provided with a beveled or inclined end 52 adapted to cooperate with brushes 53. These brushes in turn may be adjusted by means of a suitable hand wheel 54 so as to cooperate with different portions of the contact strip and thereby break the circuit at correspondingly different times. I prefer to use this adjustment of the limit switch to change the length of crop for any, given ratio between the speeds of the shear and pinch rolls.

In order to insure stopping of the shears within a predetermined time interval after the breaking of the circuit, a suitable brake 55 may be provided, this brake being indicated in Figure l as effective directly on the end of the armature shaft of the driving motor l6. As is customary in devices of this general character, the brake may be of the electrical type normally held open when the circuit is energized and adapted to be applied when the circuit is broken. Such structures are well understood in the art. The structure may be generally of the character disclosed 'in my Patent No. 1,680,048 of August 7, 1928,

although it will be understood that any other well known form of control may be utilized.

To those skilled in the art it will be understood that I have provided a system including flying shears in which the shears perform no feeding function whatsoever on the material being sheared, the main bodies of the rotors being spaced to such an extent that the material is not gripped by the rotors.

In case the peripheral speed of the'rotors at the instant of cutting is exactly equal to the linear speed of the material, there will be no interruption in the material travel such as would tend to buckle or form a loop in the material. Should the rotor speed be less, however, it will tend to hold back the material at-the instant of shearing. The upwardly arched or curved table l5 in such cases insures proper initial deflection of the material traveling thereover.

While I have throughout the specification referred to strip or generally similar material, it will be understood that the utility of the invention is not limited with respect to the particular material being handled, it being suitable for the shearing of either metallic or non-metallic material and for rods, bars, strips and other shapes.

The word strip, therefore, where used is used generically as a word of definition including material which is relatively long as compared to its cross sectional dimensions, and not'as a word of limitation.

Certain advantages of the present invention arise from the provision of a method and apparatus effective for giving accurate shearing into lengths which may be easily and conveniently varied, the shearing being effected simultaneously with a straightening or leveling operation.

Other advantages arise from the provision of a method and apparatus effective for shearing long material at a relatively high speed such, for example, as to make it effective for keeping pace with the production of a high speed continuous mill.

Further advantages arise from the provision of an apparatus effective for cropping any desired predetermined length from the front or leading end of the material regardless of the length of the regular or uniform cuts, together with means for conveniently indicating the length for which the equipment is set to cut.

Still further advantages arise from the means provided for feeding and shearing material concomitantly with a leveling operation, and under such conditions that marring due to slippage or the operation of the shears is obviated.

Still other advantages arise from the combined shear and roller leveler-pinch roll drive combination with means whereby the relative speeds may be accurately controlled and varied by progressive amounts of almost negligible amount, as distinguished from successive speed changes by predetermined increments or steps each of preliminarily predetermined and invariable order.

While I have herein illustrated and described the preferred embodiment of the present invention, it will be understood that changes in the construction and operation herein illustrated may be made without departing either from the spirit of the invention or the scope of my broader claims.

I claim:

1. In a rotary shear, rotary shear heads each carryinga shearing blade, and means for driving said rotary heads so that one of the heads rotates through an integral number of complete revolutions greater than one for each revolution of the other head.

2. The combination with a rotary shear ineluding upper and lower rotating heads. of different diameters carrying shearing means and geared together in the ratio of the pitch diameters of the rotating heads whereby the shearing means come together at every revolution of the lower head.

3. The combination with material-feeding means, of a shear including upper and lower rotating blades adapted to cooperate at intervals to execute a cutting operation on the material, a drive for said blades effective to bring the blades into cooperating, cutting relation on every revolution of the lower blade, and means for supporting the material between cuts on a level below the lowermost point in the path traversed by the edge of the upper blade.

4. In a shear, upper and lower rotors, blades carried on said rotors adapted to cooperate at intervals in effecting a cut, and means for driving said rotors at different angular velocities so related that the blades coperate to make a cut on each revolution of the lower rotor.

5. Apparatus for shearing metal lengths comprising a rotary shear, feeding means for advancing metal to the shear, a variable speed drive between said means and the shear, means for adjusting said drive to enable the shear to cut metal into various lengths, a motor for operating said drive, a limit switch for so controlling the motor as to stop the shear at a predetermined point, a drive for actuating the limit switch in accordance with the rotation of the shear, and means for adjusting the limit switch to correspond with the setting of said adjusting means to compensate for a change in the ratio of the speed of the feeding means to that of the shear, said means including a scale graduated in the various lengths to be cut by the shear, and an index cooperating with said scale.

6. The apparatus defined by claim 5 wherein the adjusting means for the limit switch comprises a shiftable drive for the latter.

7. The apparatus defined by claim 5 wherein said adjusting means comprises a planetar drive between the limit switch and the shear.

LORENZ IVERSEN.

Images