US3373588A

US3373588A - Crown control for rolling mill

Info

Publication number: US3373588A
Application number: US480398A
Authority: US
Inventors: Stone Morris Denor
Original assignee: United Engineering and Foundry Co
Current assignee: United Engineering and Foundry Co
Priority date: 1965-08-17
Filing date: 1965-08-17
Publication date: 1968-03-19
Anticipated expiration: 1985-03-19
Also published as: GB1157305A

Description

March 19, 1968 STONE 3,373,588

CROWN CONTROL FOR ROLLING MILL Filed Aug. 17, 1965 2 Sheets-Sheet 1 INVENTOR MORRIS D. STONE ATTORNEY March 19, 1968 M. D. STONE 3,373,588

CROWN CONTROL FOR ROLLING MILL- Filed Aug. 17, 1965 ZSheets-Sheet 2 MORRIS D. STONE FIGZ Midi;

HI ATTORNEY United States Patent 3,373,588 CROWN CONTROL FOR ROLLING MILL Morris Denor Stone, Pittsburgh, Pa., assignor to United Engineering and Foundry Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 17, 1965, Ser. No. 480,398 2 Claims. (Cl. 72--237) ABSTRACT OF THE DISCLOSURE The invention relates to a rolling mill having a housing in which there is formed a window. The rolls of the mill are provided with bearing chock assemblies which are received in the window of the housing. Outward of the bearing chock assemblies, the rolls are engaged by piston cylinder assemblies designed to apply a bending force on the rolls to bend them in a direction to increase the crown of the rolls. The bending forces generated by the piston cylinder assemblies are isolated from the housing by providing rigid beam members arranged between the bearing chock assemblies and the housing insuch a manner that the bending forces are self-contained, and wherein the improvement comprises providing piston cylinder assemblies designed to apply a bending force on the rolls to decrease the crown of the rolls, the last-mentioned piston cylinder assemblies being carried in the beam members so that the resultant forces thereof are taken by the beam members and not by the housing of the mill. In addition piston cylinder assemblies are provided between the bearing chock assemblies to resist the bending loads of the cylinders that exert a pressure to decrease the crown.

This invention relates to a rolling mill, and more particularly, to a mill incorporating roll deflection compensating mechanism, that is a crown control mechanism. One form of mechanism for compensating for the deflection of the rolls of the mill, which deflection results in lateral gauge inaccuracies, is to impose a counteracting bending force on the rolls to resist their tendency to deflect under the rolling loads. A successful device of this type is illustrated in US. patent application Ser. No. 468,468 entitled, Crown Control for Rolling Mill, filed June 30, 1965, by J. W. OBrien.

In OBriens patent application, to speak for a moment with respect to the upper portion of the mill, an independent beam is provided between the mill screws and the top backup roll of a four-high mill. The beam is subject to both forces required to. bend the roll and the reaction of the force which, while equal, is exerted in an opposite direction. In this way the roll bending forces are self contained and not imposed upon the housings or screws of the mill and as a result avoid what can be a very serious problem in certain types of mills incorporating compensating mechanism for roll deflection.

In the foregoing arrangement, however, the backup rolls can be bent or deflected in only one direction; namely, in a direction so that the roll bodies are urged towards the roll gap. This can represent a substantial limitation on the crown control capacity of the roll compensating device. For obvious reasons the elements involved in flexing the rolls to compensate for their deflection, can only compensate for deflections in one direction a limited amount of failure and fatigue of the parts are to be avoided.

It is one of the objects of the present invention to overcome the aforesaid limitation by providing a mill construction which will allow the roll bending forces to be applied in both directions, whereby the crown control capacity will be double that realized heretofore.

It is another object of this invention to provide in a rolling mill incorporating a crown control mechanism and beam construction as disclosed in the aforesaid US. patent application Ser. No. 468,468, a second roll bending mechanism for bending the roll in a direction to deflect the roll body away from the roll gap, wherein said mechanism is arranged so that its reaction force is also taken by the beam, together with means for resisting the roll being displaced towards the roll gap.

It is a still further object of this invention to provide in a rolling mill incorporating a crown control mechanism and beam construction as described in the aforesaid US. patent application Ser. No. 468,468, a second roll bending mechanism for bending the roll in a direction to defiect the roll body away from the material, wherein said mechanism is arranged so that its reaction force is also taken by the beam, wherein the material itself resists the bending force thus serving as a fulcrum for the roll bending forces.

In one form of the invention there is provided in a four-high mill for rolling material a pair of working rolls, each working roll having a backup roll, all of which are provided with chocks which are received in and supported by spaced-apart housings, a pair of power-operated mill screws received in said housings for moving the upper pair of rolls towards the lower ones, two beams extending between the housings and located as to the upper Ibeam between the screws and the adjacent backup roll and as to the lower beam between the housings and the adjacent backup roll, said upper beam being engaged by said screws and the chocks of the upper backing roll, a first forceexerting means connected to the ends of each backup roll for applying a bending force on the rolls in a direction to resist their tendency to deflect away from the material and thereby having the effect of increasing the crown of the rolls, the reaction force of said first force-exerting means being taken by said beams, a second force-exerting means including a first means connected to the ends of the backup rolls and second means spaced inwardly therefrom engaging the backup chocks of the backup rolls for applying a bending force to the rolls in a direction to augment their tendency to deflect away from the material and thereby having the effect of decreasing the crown of the rolls, the reaction force of said second force-exerting means being taken by said beams.

These objects, as well as others, will be more readily understood when the following specification is read in light of the accompanying drawings of which:

FIGURE 1 is an elevational view, partly in section, of a four-high mill illustrating one embodiment of the present invention, and

FIGURE 2 is an end elevational view ofthe mill shown in FIGURE 1, certain components of the mill being shown in section.

With reference to these drawings there is illustrated a four-high mill comprising two vertically arranged, spacedapart housings I1 and 12, the housings having

customary windows

13 and 14, into which is received a pair of

work rolls

15 and 16, each work roll being backed up in turn by a

backup roll

17 and 18, respectively. Either or both of the pairs of rolls are provided with a machine crown, which crown or crowns will increase or decrease by the selective employment of the crown control system of this invention.

As shown best in FIGURE 2, the journals of each roll are received in bearing checks, the work roll chocks being identified by the number 21 and the backup bearing chocks by the number 22. In the customary manner the work rolls are urged away from each other and against their respective backup rolls by balance piston cylinder assemblies 23 mounted in the lower work roll chocks 22. In addition to these piston cylinder assemblies, between the backup roll chocks 22 and mounted in the lower chocks, there are provided a pair of piston cylinder assemblies 24 on each side of the mill. Each pair of these cylinders are directly connected with one of the cylinders of the second crown control force-exerting mechanism, yet to be described, and delivers the same force as the seconcl force-exerting mechanism. In this manner, the rolls are prevented from forcibly contacting each other and causing damage to themselves and the associated parts.

With reference now to the upper portion of the mill, it will be noted that between the housings and extending through the

windows

13 and 14 there is a horizontally arranged beam 25 in which, for brevitys sake, reference will be made to only one side of the mill. The lower surface-of the beam in the vicinity of the chock 22 is provided with a rocker plate 26 which engages a similar rocker plate 27 formed on the top of the adjacent backup roll chock. Directly across from the area where the beam engages the chock and on its upper surface there is provided a raised portion which receives a breaker block 28, the top of the breaker block having a spherical surface which is engaged by a complementary surface formed at the bottom of the screw 29. The screw 29 is received in a nut 32 formed in the housing 11, the screw being rotated sly a worm and wheel not specifically shown on the drawngs.

Drawing attention now specifically to the beam 25, as shown in FIGURE 1, the center is connected to a rod 33, which extends in a vertical direction. To the upper end of the rod 33 there is connected a piston 34 of a piston cylinder assembly 35 mounted on a separator 36 that connects the housings 11 and 12 together at the top of the mill. The piston cylinder assembly 35 is employed to urge the chocks 22 against the beam 25 and the beam against the screws 29. To this end, the beam at its lower end is provided with opposed downwardly extending hooks 37 which cooperate with projections 38 formed at the top of the chocks 22, whereby in operation of the piston cylinder assembly 35 the hooks engage the chocks and bring them into contact with the bottom of the beam.

Still referring to the top of the mill, it will be noted that at the outer portion of the housings there is provided at each side of the mill cylinders 41 which, as shown at the left of FIGURE 1, receives two pistons, 42 and 43, one extending from the top of the cylinder and the other extending from the bottom. The cylinders and piston constitute the first force-exerting crown control mechanism for the top backup roll and are employed as previously noted to deflect the backup roll towards the material, that is to effect an increase in the machine crown of the rolls.

The lower piston 43 engages a rocker plate 44 carried by the beam 25, the rocker plate being provided with a spherical surface which cooperates with a spherical surface formed at the end of the piston, thereby allowing for any relative movement between the two pieces. The upper piston 42, as shown best in FIGURE 2, is connected to a cross member 45, to the ends of which there are connected identically pivotal links 46 which extend downward of the rolls on the outside of the

windows

13 and 14.

With reference now to the upper backup roll 17, and in still referring to but one side of the mill, it will be noted that outward of its main bearing chock 22, there is provided a second bearing chock 47 which, as shown in FIG- URE 2, is provided with opposed projecting horizontal wings 48. The lower ends of the links 46 are formed so .as to engage the wings 48 of the bearing chock 47 whereby :the bending force exerted by the cylinder 41 through the piston 42 is imposed upon the end of the roll 17 causing the center portion of the roll to bend in the direction of the work roll 15.

It will be appreciated that upon the operation of the cylinder 41, a force is imposed upon the beam 25 by the piston 43 in a direction toward the work roll and a force is imposed upon the roll by the piston 42 which imposes a second force upon the beam in a direction opposite from the first force. Hence, there is a closed force circuit de veloped whereby not only are there not any reaction forces 4' imposed upon the housings 11 and 12, but the screws 29 are rendered free from any bending forces.

Turning now to the second force-exerting mechanism for controlling the crown of the

backup rolls

17 and 18, and in still referring to the upper portion of the mill and one side thereof, FIGURE 1 illustrates that between the ends of the backup roll 17 at each side of the mill andthe beam 25 is a second force-exerting means in the form of a piston cylinder assembly 49. The rod end of the piston engages the top of the bearing 47 against which it applies a force to deflect the roll 17 and effect a subtraction of the machine crown of the roll. The cylinder, in turn, is secured to the bottom of the beam 25 so that the beam receives the reaction forces of the cylinder. The pressure of the fluid fed to the piston cylinder assembly 49 as well as its effective pressure area, equals that of the pair of piston cylinder assemblies 24 and the assemblies are directly tied together so that any change in the pressure of the cylinder 49 would effect a change in the pressure of the cylinders 24.

A generally similar arrangement is provided for the lower backup roll, in which connection there is a lower beam 51 which extends between the housings 11 and 12 and through the

windows

13 and 14 thereof, this being best shown in FIGURE 1 which also shows that the beam carries the bearing chocks 22 of the lower backup roll 18. F or completion of the description and in referring to one side of the mill, it will be noted that the chock 22 is separated from the beam by a series of filler plates 52 which are replaceable so as to compensate for the various diameters of the rolls employed in the mill. This, of course, is quite customary in mill design. FIGURE 1 also shows the relationship between the beam 51 and the housing 11 wherein the beam rests upon the housing, there being rocker plates 53 provided so as to allow for relative movement between these two elements. Outward of the ends of the beam there are provided on the housings 11 and 12, cylinders 54. The cylinder, in referring to one side of the mill, as in the case of the cylinders 41, is provided with two opposite arranged

pistons

55 and 56, 55 being the upper piston which engages the lower surface of the beam 51 through a spherical bearing block 57 provided for allowing for relative movement between the beam and the piston 55. The piston 56 extends downwardly from the cylinder 54 and is connected to a cross member 58, to which are pivotally secured at its outer ends, elongated links 59 extending toward the work roll in such a way as to be clear of the

windows

13 and 14.

Outward of the main bearing chock 22 of the lower backup roll 18 is a second bearing chock 62, the chock of which, as shown in FIGURE 2, has horizontal wings 63 engaged by the links 59 and through which means the bending force of the piston cylinder assembly 54 is applied to the lower backup roll 18 in a way to bend the central portion of the roll in a direction of the lower work rolls 16. This arrangement, as in the arrangement provided for the upper backup roll 17, provides a closed force circuit wherein the piston 55 imposes a force on the beam 51 in one direction and the piston56 imposes an equal, but opposite, force on the beam through the chock 22, whereby the bending forces are self contained and are not imposed upon the housings 11 and 12.

As shown in FIGURE 1, the lower backup roll 18 is also provided with a second force-exerting mechanism which takes the form of a piston cylinder assembly'64 at each side of the mill. As in the case of the piston cylinder assemblies 49 at the top of the mill, the cylinders of the assemblies 64 are carried by the beam 51 and the piston thereof engages the adjacent surf-ace of the outer bearing 62 of the lower backup roll 18.

In operation the first force-exerting

cylinders

41 and 54 will be operated in unison whenever it is desired to in crease the effective crown of the roll. To decrease the effective crown of the rolls, the

cylinders

49 and 64 will be operated in unison.

It will be appreciated that various components of the mill illustrated have not been referred to since they are quite common and that some elements have not been shown, since again they are Well known in the art. It will be further appreciated that while the present invention had been illustrated in connection with a four-high mill, it may be used in other types or mills as well as other types of processing equipment, such as rubber and paper calenders.

In accordance with the provisions of the patent statutes, I have explained the princple and operation of my invention and have illustrated and described what I consider to represent the best embodiment thereof. However, I desire to have it understood that Within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

1. In a rolling apparatus including:

a pair of cooperative material reducing rolls having central portions adapted to deflect away from the material being rolled under the rolling loads, the shape of the central portions of said rolls defining crowns of the rolls,

a housing having a window for receiving the rolls,

bearing chock assemblies mounted on the ends of the rolls for rotatably supporting the rolls in said housat least one of said rolls having opposed end portions extending outward of said bearing chock assemblies,

a cross member arranged parallel to said one roll and between its bearing chock assemblies and said housing and having portions extending outward of the bearing chock assemblies of said one roll,

first force exerting means for each extending portion of said one roll having displaceable elements connected to the roll extending portions for imposing bending forces thereon to add to the crown of the roll and cause the central portion of said roll to deflect in a direction towards the material,

said first force exerting means arranged with respect to said cross member that the reaction forces exerted by the displaceable elements are taken by the cross member and not by the housing,

the improvement comprising a second force exerting means for each extending portion of said one roll having displaceable elements connected to the roll extending portions for imposing bending forces thereon to subtract from the crown of said one roll and cause the central portion of said roll to deflect in a direction away from the material, and

pressure exerting means arranged between said bearing chock assemblies constructed and arranged to resist displacement of said one roll in a direction towards the material upon applying the bending force by said second force exerting means.

2. In a rolling mill according to claim 1 wherein said means for resisting displacement of said one roll includes piston cylinder assemblies arranged between an opposed pair of bearing chock assemblies, said piston cylinder assemblies arranged to provide equal and opposite forces with respect to the forces exerted by the second force exenting means.

References Cited UNITED STATES PATENTS 1,935,091 11/1933 Iverson 72-245 3,171,305 3/1965 Stone 72-241 3,212,314 10/1965 Sieger 72225 CHARLES vV. LANHAM, Primary Examiner. A. RUDERMAN, Assistant Examiner.