US2056409A

US2056409A - Rolling mill

Info

Publication number: US2056409A
Application number: US679608A
Authority: US
Inventors: William G Ross
Original assignee: Individual
Current assignee: Individual
Priority date: 1933-07-10
Filing date: 1933-07-10
Publication date: 1936-10-06
Anticipated expiration: 1953-10-06

Description

W. G. ROSS ROLLING MILL Oct. 6, 1936.

Filed July 10, 1955 3 Sheets-Sheet 1 INVENTOR wl/ham fios:

A TTORNEY Oct. 6, 1936. w 3 055 2,056,409 I ROLLING MILL Filed July 10, 1933 3 Sheets-Sheet 2 IN VEN TOR ATiORNEY W////am 6. E055.

W. G. ROSS ROLLING MILL Oct. 6, 1936.

Filed July 10, 1935 3 Sheets-Sheet 3 INVENTOR W////am 6. Ross 7 A ORNEY Patented Oct. 6, 1936 UNITED STATES PATENT- OFFICE 10 Claims.

My invention relates in its broadest aspect to the metal rolling industry and in particular it is concerned with the provision of an accurate mechanism for reducing the gauge of materials such as metal. Although my invention is hereinafter described with particular reference to the reduction of metals by rolls, it will be understood that my improved apparatus is susceptible of various other applications within the spirit and scope of the appended claims.

In the development of metal rolling practice considerable time and effort have been directed towards the proper temperatures and speeds at which various metal alloys should be rolled in order to obtain the required metallurgical and physical properties in the finished product. It has been further found that the grain size and various other metallurgical phenomena are, at least in 'part, a result of the strain to which the metal is subjected by the rolls of a rolling mill during the reduction thereof.

Rolling mill equipment, in its present stage of development, has, to a certain degree, met the requirements of temperature and speed control, but only at the expense of inferior accurate pressure-applying mechanisms. For example, hot mills, accurately controlled roll temperature mechanisms, and variable speed mills are quite common mechanisms in the rolling industry. These apparatus are, however, equipped with the conventional mechanical screw-down devices in the majority of designs and in some few cases provided with fluid-operated screw-downs. In other words, one of the most important features of rolling mill equipment, namely; the pressureapplying mechanism, has experienced very little, if any, major improvement since its inception, with the result that difficulty is being experienced in the production of rolled products, wherein pressure is such an important factor.

With reference to the general type of rolling mill equipment now in use, and with particular reference to mechanical screw-down devices, it will be seen that the pressure applied to a product passing between the rolls of a conventional mill is a reaction pressure produced by the metal upon the rolls. In mills of this type the vertical pressure-applying screws are subjected to the reaction pressure which is transmitted directly to the screw threads. It will be obvious then that the weakest portion of the screws carries the load on the mill and that considerable wear of an important feature of the mill results. The wear on the screws of a mill is cumulative. in effect and it will be understood by those versed in this art that it is almost, if not impossible to return the screws of a mill to a predetermined pass opening between the rolls thereof without considerable difficulty on the part of an operator.

In mills employing fluid-operated screw-down mechanisms, wherein a fluid pressure is adapted to apply pressure to the movable roll of a mill, the pressure is usually supplied by a suitable pump and accumulator mechanism. Such mechanisms employ large quantities of fluid and, as is well known, are sluggish in operation. Furthermore, the application of fluid pressure from pumps is pulsating in nature, which pulsations, even though transmitted through an accumulator, are directly transmitted to the rolls of the mill with the resultant deleterious effect of uneven pressure on the product being-rolled.

By my improved rolling mill I have overcome the disadvantages of prior equipment and provided a mechanism which is accurately controllable from a pressure-applying standpoint.

It is an object of my invention to provide a pressure-applying mechanism for rolling mills which permits the accurate application of variable pressures to the rolls of the mill.

It is a further object of the invention to provide a simple and economically constructed pressure-applying mechanism which is adaptable to conventional rolling mills without undue reconstruction of the same.

Another object of my invention is to provide a rolling mill the pressures on the rolls of which may be accurately known at all times during a metal-reducing opelation.

A further object is to provide a metal processing mechanism which incorporates, as a feature of its construction, an accurately controllable, variable pressure-applying mechanism.

Other objects and advantages will present themselves on consideration of the following description.

In the drawings accompanying this specification and forming a part thereof, certain preferred embodiments have been illustrated. Although the novel features which are believed to be characteristic of the invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and advantages, the mode of its operation, and the manner of its organization may be better understood by referring to the following description thereof with reference to the accompanying drawings. in which:

Fig. 1 represents an elevational view of a variable pressure-applying mechanism, embodying the principles of my invention, associated with a to an enlarged scale taken along the line IV-IV of Fig. 1;

Fig. 5 represents a fragmentary sectional view to an enlarged scale taken along the line V-V of Fig. 1;

Fig. 6 represents an end view in partial section as viewed in the direction of the arrows VI--VI in Fig. 1;

Fig. 7 represents an end elevation of arolling mill in which the variable, pressure-applying mechanism of Fig. 1 is adapted to the bottom roll thereof;

Fig. 8 represents, in side elevation, a. modification of the variable, pressure-applying mechanism shown in Fig. 1;

Fig. 9 represents a top plan view of an organized rolling mill in which a variable, pressure-applying mechanism, embodying the principles of my invention, has been incorporated as an integral part of the mill structure;

Fig. 10 represents an end elevational view of the mechanism shown in Fig. 9, features being shown in section to more clearly illustrate the mode 01! construction employed;

Fig. 11 represents a section taken along the line XI-XI of Fig. 10;

Fig. 12 represents a fragmentary exterior end view of a portion of the mechanism shown in Fig. 1;

Fig. 13 represents, in diagrammatic form, a plurality of rolling mills arranged in tandem and adapted to be operated in conjunction with the accurate pressure-applying. mechanisms illustrated in Figs. 1 and 8.

In describing my invention I have elected to disclose it in connection with a two-high rolling mill of conventional construction. The general form of the mill selected is well known to those versed in this art. It will be quite manifest that the invention is readily adaptable to various other forms of metal processing or rolling equipment incorporating any suitable number of rolls, it usually being only necessary to have at least one roll which is movable with respect to an adjacent roll.

In the following detailed description of the invention, like reference numerals have been employed to designate similar parts of the illustrated mechanisms.

Referring to the drawings, and in particularity to Figs. 1 to 6 inclusive, a two-high rolling mill is illustrated in end elevation having a mechanism associated therewith for the purpose of providing variable pressures .to the movable top roll of the mill. The mill, as shown, is of conventional form, its customary screw-down mechanism being replaced by a device which adapts the mill to the principles of my invention.

The mill, one end only of which is shown, comprises end housings l0 supported in the customary manner upon guide shoes ll. The end housings are provided with windows l2 within which two rolls l3 and II are suitably supported. The lower roll i3 is joumalled in bearings I! mounted within bearing blocks l6 which are stationary with respect to their adjacent parts but which be understood that fluid pressure from the accumulator 2| to cylinders 20, through the connecting conduit 22, will be supplied in suflicient amount to just overcome the dead weight of the upper roll l4 and its associated parts to thus maintain the upper and lower rolls separated except when pressure is applied to the upper roll.

Fluid cylinders 24 are provided within the top portions of the housings 10 where normally are located threaded members to receive the conventional screws of a mill. These cylinders are preferably provided with brass or other suitable liners 25 and receive pistons 26 formed at their lower ends with spherical bearing portions 21 for the purpose of contacting bearing blocks 28 within which the upper hearings or journals 29 are suitably secured. The bearing blocks 28-are slidably mounted within the windows l2, and the bearing portions 21 of the pistons 26 are preferably weakened, as by annular grooves 30, to permit fracture under excessive load, and thereby protect the mill against damage. The upper ends of cylinders 24 are suitably sealed or closed by fluid-tight caps 3|, whereas the lower or bottom ends are open to permit the aforementioned contacting of the pistons 26 with the bearing blocks 28. Also a fluid inlet. conduit 32 is provided adjacent the upper ends of the cylinders, the purpose of which will be hereinafter observed.

Located adjacent the mill previously described is a mechanism for accurately supplying variable, fluid pressures to the cylinders 24. This mechanism is of unitary construction and comprises a base member 33 within the legs of which two vertically

adjustable screws

34 and 35 are mounted. Each screw is supported in threaded engagement within a nut member 36 suitably positioned within cavities 31 in the legs of the base member 33, and the exterior peripheries of these nuts are constructed in the form of worm wheels which are arranged to mesh with worms 38 (Figs. 3 and 6) formed as by machining the same on the horizontal shaft 39. The shaft 39 is journalled at its ends in suitable bearings 40 inserted within the legs of the base 33, and preferably end thrust washers 4| are provided to take up the end thrust exerted by the shaft during its rotation by a. reversible motor 42 directconnected to the shaft 39 through the medium 01' I the intermeshing gears 43, 44. By this construction the

screws

34, 35 may be vertically adjusted in unison.

A beam member, represented in its entirety by the reference numeral 45, is pivotally associated with the vertical screw 34 and is connected thereto by forming the screw 34 with an eye 46 at its upper end. A fulcrum pin 41 extending through the webs of spaced I sections 48, constituting the beam, also extends through the eye 46, and spacer tubes 49 (Fig. 5) mounted on the pin 41, on either side of the eye 46, insure the central location of the beam with respect to the screw 34. The proper spaced relationship of the I sections 48 isobtained by means oticro'ss plates 5| suitably secured to the upper or top flanges of the Is 48.

Bearings in the form of suitable pillow blocks 5| secured to the plates 50 provide means for supporting a horizontal lead screw 52 the ends of which are reduced in diameter and secured against axial movement within the pillow blocks. The end of lead screw 52, adjacent the vertical screw 34, extends through its pillow block hearing an appreciable distance where it is coupled, by means of a suitable coupling 53, to the shaft of a reversible motor 54 mounted upon a bracket 55 secured in any suitable manner to the PS 48, this construction providing means for rotating the screw 52 in either direction. A weight 56 provided with an internal threaded portion 51 is mounted upon the lead screw 52 and is equipped with flanged wheels 58 adapted to roll upon the top flanges of the 1's 48.

Intermediate the

screws

34 and 35, and preferably adjacent the screw 34, a fluid cylinder 59 is provided within the base 33. In the particular illustration being described, the cylinder 59 is formed integral with one of the legs of the base 33 and is provided with a suitable corrosion-resistant liner 60. A plunger or ram 6! slidably received within the liner 60 is link-connected to the beam 45 by means of a clevis 62 supported upon a pin or shaft 63 extending through the webs of the Is 48, a second pin 64 pivotally connecting the clevis to an eye in the upper end of the ram 6! (Fig. 4). Spacer tubes 65 mounted upon the pin 63 on opposite sides of the clevis 62 insure coincidence of the axis of the ram 6! and beam 45. This link connection provides for vertical movement of the plunger 6| for various positions of the beam 45 with respect to oscillatory movement thereof about its fulcrum or pivot center 41.

The aforementioned conduits 32, communicating with cylinders 24, are connected in any suitable manner to the cylinder 59 (Fig. 2) as by means of the line of conduit 66, and it is apparent that there may be a separate pressureapplying mechanism for each cylinder'24 or one mechanism as described herein. It is preferable to provide for a supply of fluid to the system, and in the mechanism herein shown a suitable tank 61 is connected through a check valve 68, or other suitable operating valve, to the fluid system which permits replenishment of any fluid lost as by leakage past the pistons 26 and ram As has been previously described, the

screws

34 and 35 are vertically adjustable and move in unison during their adjustment. It is a feature of my mechanism, however, that the upper end of screw 35 be spaced from the beam 45 when the beam is in its horizontal position (Fig. 1). Fur thermore, the position of weight 56, with respect to the axis of screw 34, is accurately indicated by means of any suitable form of indicating meter 69 which is illustrated as direct connected to lead screw 52 and supported upon a suitable bracket 10 secured to the beam 45. In this connection it is preferred that the meter 69 be calibrated in pounds per square inch pressure so that the weight may then be translated along the beam 45 to a definite position for an accurate pressure at the rolls, as indicated by the meter 69. Furthermore, it will be apparent that the meter 69 may be direct connected to the motor 54, if desired, or located at some remote position with respect to the actual screw 52, any suitable mechanical or electrical indicating means being considered satisfactory and adaptable to the present mechanism.

In the operation of my improved rolling mill, the weight 56 is positioned over the screw 34, by means of actuating the electric motor 54,wherein the axes of the screw and weight are coincident and the beam 45, which is balanced in this particular position of weight 56, floats or rides horizontally on its pivot 41. The

screws

34 and 35 are thereafter raised or lowered through the motor-driven shaft 39 and its worm and

worm wheel connections

38, 36, until the desired mill pass or roll opening is obtained. In this connection an indicating mechanism, in the form of a micrometer scale H secured to screw 34 (Fig.

12), and cooperating with a suitable pointer 12', fixed on the housing 33, is preferably provided for the purpose of indicating the pass opening between the rolls I3 and i 4. The raising or lowering of the

screws

34, 35 automatically distributes the fluid -contained within the closed system represented by the

cylinders

24 and 59 and the line of conduit 66. With the raising of the

screws

34, 35 or beam 45, the accumulator 2| automatically functions to raise the top roll 14, and the reverse action on the beam 45 will overcome the accumulator pressure. Assuming that the desired pass opening has been acquired, the weight 56 is now translated away from its position over the screw 34 to a desired pressureapplying position as indicated by the meter 69. This action automatically oscillates the beam 45 until the bracket 10 comes in contact with the screw 35 and actually closes the rolls or at least brings them closer together than the pass opening desired. Introduction between the rolls i3 and 14 of a slab or strip of material, such as 13 (Fig. l) will cause the beam to immediately assume its horizontal or floating position, which normal operating position represents a definite and accurate pressure at the rolls. Exemplary of the operation of the mechanism, assuming the weight 5 Fig. 1) to weigh 10,000 pounds, the horizontal distance of the center of gravity of weight 56 from pivot center 4'! to be 10 feet, the distance from the axis of pivot center 41' to the axis of the ram 6| to be 1 foot, and the cross sectional area of ram 6! to be 20 square inches, the magnitude of the pressure applied on the pistons 26 will be: I

we 1X20 or 5,000 pounds per square inch.

It will be obvious that the pressures applied in this manner may be varied and that the in numerable positions of the weight 56 along the beam 45 permit a wide range of pressures for each increment of adjustment of the

screws

34 and 35. The pressures thus applied are also extremely accurate since, unlike the conventional screw-down mechanisms, there is no direct accumulation of errors, such as wear on the screws, since the reaction pressures of the metal on the rolls are not transmitted into a mechanical thread but into a fluid, the lead screw 52 in my improved mechanism never being subjected to the reaction pressures at the rolls, as is the case in standard or conventional mill screw-downs. It is also of extreme importance that the elimination of wear makes it possible to reproduce a given pressure at a given metal gauge, which reproduction is practically impossible in mechanisms now in use.

Referring now to Fig.7, an end elevational view of a twohigh mill is disclosed in which the line of conduit 66 of the mechanism above described and shown in Fig. 1 is connected to cylinders 14 formed as integral parts of the end housings I5 adjacent the base of the mill. In this modification of my invention the top roll I6 is conventionally supported upon a lower bearing 11 resiliently mounted in a cradle structure I8, and the usual screw-down mechanism I9 is provided in direct contact with the upper bearing blocks 80 slidably mounted within the mill windows 8I, bearings or brasses 82- being suitably secured within the blocks 80.

The lower roll 83 in this instance is supported by means of bearings or brasses 84 mounted within the slidable bearing blocks 85, and pistons 8B, slidably mounted in the aforementioned cylinders I4 are adapted to exert accurate pressures on the lower roll as previously described in connection with the mechanism disclosed in Fig. 1.

It will be quite manifest that the advantages of accurate control and duplication or reproduction of pressures is possible with the arrangement shown in Fig. '7, as is the case in the previously discussed mechanism, and that a. wider range of pass opening may be obtained in that the screw-down mechanism I9 permits a separate means of opening and closing the rolls I6 and 83.

In Fig. 8 a modified form of variable pressureapplying mechanism is illustrated which is adaptable to finishing mills wherein the pass opening between the rolls remains constant and it is only required to vary the pressure for this given pass opening. The mechanism herein shown comprises a base member 81 having a vertically projecting standard 88 at one of its ends to which a beam 89, similar in all respects to the beam 45 shown in Fig. 1, is pivotally attached as at 90. A cylinder 9| is formed integral with said base and receives a piston or ram 92 which is linkconnected to the beam 89 as at 93. The opposite end of the base has a vertically projecting standard 94 formed thereon to limit the downward movement of the beam 89 as the reaction pressure on the mill rolls is relieved by the discharge of a strip of metal. In this manner the standard 94 (Fig. 8) performs the same function as the screw 35 (Fig. 1).

In the operation of the mechanism shown in Fig. 8, the cylinder 9I is suitably connected to a mill the pass opening of which remains constant, as in finishing operations, and the weight 95 is translated along the beam 89 into its various positions to provide accurate pressures on the metal being processed. There is no adjustment provided for in the position of the ram 92 within its cylinder 9|, as provided for by the screws 34, 35 (Fig. 1), and the only adjustment for pass opening in this particular modification of my invention must be made in the mill in which this mechanism is incorporated. The mill shown in Fig. 7 could be readily adapted to this purpose in that the screw-down I9 would permit adjustment of the pass opening whereas the mechanism in Fig. 8 would provide for variable and accurate pressures on the rolls.

Referring now to Figs. 9, 10, and 11, an organ-. lzed rolling mill is disclosed in which the variable pressure-applying mechanism is incorporated as a unitary construction. The mill comprises end housings 98 provided with the customary windows 91 within which a pair of

rolls

90, 99 are supported in suitable bearings. As in the illustration shown in Fig. 1, the top roll is supported upon a cradle structure I and is balanced by means of the accumulator I 0| or similar constant pressure-applying mechanism, which is in direct communication with the pistons I02 operating in the cylinders I03, the pistons being attached to the cradle structure I00. This construction permits the balancing of the top roll .98 out of contact with-the lower relatively stationary roll 99 as will be well understood by those versed in this art.

Mounted upon the top surface of the mill is a beam I04 which is similar in all respects to that shown in Figs. 1 and 8, vertically adjustable screws I05 and I06 being provided for supporting the beam, the pivot center I0I for the same incorporating the screw l05 and the connection to the beam being similar to that shown in Fig. 5. Likewise a cylinder I08 is formed or provided within the mill casting adjacent the screw I05, a suitable corrosion-resistant liner I09 being provided within the cylinder. A ram or piston H0 is slidably mounted within the lined cylinder and is link-connected to the beam I04, as at III, similarly to the connection shown in Fig. 4.

The screws I05 and I05 are mounted in thread- ;ed engagement with nuts II2 suitably mounted in cavities II9 formed in the projecting portions H4 01' the main mill casting. The peripheries of the nuts II2 are in the form of worm wheels and are adapted to engage worms II5 mounted, or otherwise formed, on shafts IIB suitably journalled in the projecting portions II4. These shafts II6 are driven in unison in any suitable manner (not shown) whereby the beam may be raised or lowered for the purpose of adjusting the pass opening between the

rolls

98 and 99.

Provided in the upper portions of the end housings 96 are cylinders III in which corrosion-resisting liners II8 are secured. These cylinders open into the mill windows 91 and are sealed or capped at their opposite ends by suitable cap members H9. Pistons I20 having weakened bearing portions I2I are slidably mounted in these lined cylinders, the bearing portions being adapted to contact the bearing blocks of the upper roll 98. Communicating passages I22 connect the cylinder I08 with cylinders III whereby the pressure exerted by the ram I I0 is equally distributed on the pistons I20.

Fig. 11 shows a safety guard construction which may be incorporated in any one or all ofthe mechanisms shown in Figs. 1, 8, and 10. This mechanism comprises a channel-shaped member I28 secured to the vertical screw I06, the upstanding legs of the channel being turned inwardly as at I24 to limit the movement of the beam I04 in a counterclockwise direction about its pivot center I01. Such movement of the beam is not contemplated in the actual operation of my mechanism but is susceptible of occurring if for any reason material of a gauge too great for the particular pass opening between the rolls is inserted therebetween, which action would cause a quick movement of the beam in a counterclockover the pivot center ill! to maximum pressure at the extreme right of the beam.

In Fig. 13 aplurality, four in number, of twohigh rolling mills 128 are arranged in tandem, in

which arrangement they are positioned to receive a strip of metal I29 to continuously reduce the gauge thereof in each successive mill, reading from left to right. Each mill is provided with a cylinder I30 and cooperating piston l3l adjacent the top roll thereof, and the cylinders 130 are supplied by pressure through a suitable conduit I32 from any one of the pressure-applying mechanisms shown in Fig. 1 or 8. In this modification of my invention the cylinders I30 are proportioned from left to right in such a manner that a constant pressure produced by the mechanisms illustrated in Figs. 1 and 8 will automatically provide a definite pressure upon each of the pistons i3! in accordance with the cross-sectional area thereof. In this manner it is possible to operate a continuous mill, such as represented by the tandem arrangement herein shown, and provide a series of definite pressures at each mill for each position of the

weight

56 or 95 in Figs. 1 and 8, respectively, The above arrangement illus trates that the pressure in each succeeding mill is increased as the gauge of the material I29 is decreased. It willbe apparent, however, that the opposite result can be obtained by introducing the material from right to left.

In the various illustrations of my invention described heretofore, it is of importance to note that the reaction pressure upon the rolls of the mill is transmitted directly into the fluid within the pressure-applying cylinders. The actual load-applying device comprises a pivotally mounted beam upon which a weight, adjustable with respect to its position relative to the pivot center of the beam, is supported. This construction does not involve excessive amounts of fluid or mechanical devices which offer the disadvantages of the equipment now in use, and by proportioning the length of the pivotally mounted beam, with respect to the distance of the pivot center from the pressure-applying ram axis, a variation in pressure between wide limits may be accurately obtained through the use of a relatively small weight. Other of the many advantages of my mechanism include the ease of adapting the pressure-applying mechanism to conventional rolling mills and the accuracy with which a pressure may be applied to the rolls of a mill and thereafter reproduced as required in subsequent rolling operations. Also the speed at which the weight may be accurately moved into position on the pivotally mounted beam is far superior to any of the mechanisms now in use, which, for the most part, are cumbersome and require a longer time-interval to adjust and set in operation. This is particularly the case in hydraulic installations employing large quantities of fluid.

It is apparent that the principles of my invention may be incorporated in various forms and types of rolling mill equipment for reducing gauge and obtaining definite physical properties under known rolling conditions. For example, the variable pressure-applying mechanisms illustrated and described could readily be employed for aplying ac"urate pressures to a line of mills, all

of which would be connected to a pressure main which received its pressure from a single pressureapplying mechanism as herein described. Other arrangements will undoubtedly suggest themselves to those familiar and versed in this art, and it is not necessary to illustrate and describe the numerous modifications and embodiments in which my invention may be practiced.

Having thus described and explained my invention and its mode of operation, it is to be understood that the mechanisms herein described were selected merely for purposes of illustration and that numerous variations in the form and arrangement of parts shown and described may be made without departing from the nature and scope of my invention, except as defined in the appended claims.

What I claim is:

1. A fluid pressure-applying mechanism comprising a beam member pivotally mounted adjscent one of its ends upon a vertically adjustable screw, a second vertical screw adjacent the opposite end of said beam and spaced therefrom, said screws being adapted to be moved in unison to permit the raising and lowering of the beam, a ram connected to said beam and received within a cylinder, a weight movably supported upon said beam and adapted to be translated along the same to apply a variable turning movement of the beam about its pivot, said' turning movement being resisted by fluid contained within said cylinder below said ram, and said second-mentioned screw providing a stop limiting the movement of the beam.

2. In combination with a rolling mill, pressureapplying means including a pivotally mounted beam member associated with the rolls of said mill, said beam member being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any desired constant gauge of material rolled thereby.

3. In combination with a'rolling mill, pressureapplying means including a pivotally. mounted beam member associated with the rolls of said mill, an adjustable weight member supported by said beam and adapted to normally oscillate the same, said beam member being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any desired constant gauge of material rolled thereby.

4. In combination with a rolling mill, pressureapplying means including a pivotally mounted beam member associated with the rolls of said mill, a weight supported by said beam member and adapted to normally oscillate the same, and means for translating said weight along said beam member, said beam member being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any desired constant gauge of material rolled thereby.

5. Incombination with a, rolling mill, pressur applying means including a pivotally mounted beam member associated with the rolls of said mill, fluid pressure-transmitting means associated with said beam member and rolls, said beam member being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any constant gauge of material rolled thereby.

6. In combination with a rolling mill, pressureapplying means comprising a pivotally mounted beam member, fluid pressure-transmitting means '7. In combination with a rolling mill, pressureapplying mechanism for applying pressure at the rolls or said mill, said mechanism including a pivotally mounted beam member, a piston connected with said beam member, said piston being disposed within a fluid cylinder in pressure communieation with the rolls of said mill, a weight member movably supported on said beam member, said weight being adapted to exerta pressure upon fluid within the fluid cylinder, and said beam being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any desired constant gauge oi! material rolled thereby.

8. In combination with .a rolling mill, a pressure-applying mechanism including a fluid pressure-transmitting system in pressure communication with the rolls of said mill, a beam member pivotally mounted and adapted to exert a pressure in said pressure-transmitting system, and a weight movably supported on said beam member for translation along said beam to vary the pressure exerted thereby, said beam member being adapted to assume a horizontal position in balanced relationship with the pressure exerted at said rolls for any desired constant gauge of material rolled thereby.

9. In combination with a plurality of rolling mills arranged in tandem, a pressure-applying mechanism comprising a fluid pressure-transmitting system in pressure communication with a fluid cylinder and the rolls of said mills, a piston reciprocally disposed within said cylinder adapted to exert a pressure upon fluid within said pressure-transmitting system, a beam member piv.- otally supported and interconnected with said piston, a weight member associated with said beam member and adapted to be variably positioned along the length of said beam member, said beam member for all positions of said weight being adapted to assume a horizontal position in balanced relationship with the pressure exerted at the rolls of said mills,

10. In a method of rolling, the steps comprising, providing a metal working means in the form of a roll and a pressure-applying instrumentality in the form of a pivotally mounted weight-supporting beam, pressure-loading said beam member by positioning said weight along the same, and

maintaining said beam member in horizontal position for all positions of said weight to exert a constant pressure on the metal being worked.

WILLIAM G. ROSS.