US3364715A

US3364715A - Crown control for rolling mill

Info

Publication number: US3364715A
Application number: US468468A
Authority: US
Inventors: O'brien Jeremiah Wagner
Original assignee: United Engineering and Foundry Co
Current assignee: United Engineering and Foundry Co
Priority date: 1964-07-08
Filing date: 1965-06-30
Publication date: 1968-01-23
Anticipated expiration: 1985-01-23
Also published as: DE1452113B2; DE1452113A1; GB1107727A

Description

CROWN CONTROL FOR ROLLING MILL Filed June 50, 1965 2 Sheets-Sheet 1 1 NVE N TOR. JfQ/FMMI/ 14 OZR/E/V ATTORNEV.

Jan. 23, 1968 J. w. O'BRIEN 3,364,715

CROWN CONTROL FOR ROLLING MILL Filed June so 19 5 2 Sheets-Sheet 2 INVENTOR. JfQA-M/Af/ 14/. 0272/5 United States Patent 3,364,715 CROWN CONTRGL FGR ROLLING MILL Jeremiah Wagner OBrien, Mount Lebanon, Pa., assignor to United Engineering and Foundry Company, Pittsburgh, Pa., a corporation of Pennsylvania Filed June 30, 1965, Ser. No. 4 58, 168 Claims priority, application Great Britain, July 8, 1964, 28,232/ 64 7 Claims. (Cl. 72241) ABSTRACT OF THE DISCLOSURE This 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 control their crowns with reference to their tendency to deflect when subject to the rolling loads. The bending forces are isolated from the housing by providing a rigid beam member arranged between the bearing-chock assemblies and the housing in such a manner that the bending forces are self-contained.

This invention relates to a rolling mill and, more particularly, to the type of a mill in which there is provided roll deflecting means for controlling the crown of the rolls.

In order to obtain close gauge tolerances and flatness, modern mills have been provided with a mechanism for applying roll deflecting forces to the rolls in order to control their contours. It will be appreciated that in a normal rolling mill the rolling loads are applied to the center of the roll which flexes or bends the rolls between their journals. This flexing, unless taken up by a machine crown which will compensate for the deflection, produces a product having a variable thickness across its width.

Not only is such a result objectionable from a thickness standpoint, but in certain cases buckles are formed in the strip which cause the strip to be unflatv In an etfort to alleviate these conditions, as previously mentioned, there have been employed crown control devices which flex the rolls to counteract for the inherent deflection caused by the rolling loads. Such devices have been very successfully employed for the backup rolls of 4-high mills, which includes hydraulic cylinders arranged to take two separate forms. The cylinders were either mounted between the journals of the backup rolls, whereby two cylinders provide equal and opposite forces to bend the rolls, and in the second form the cylinders are mounted on the housings themselves, a cylinder being provided for each roll end. In the latter construction, which has the advantage of allowing quick work roll changing, since in this arrangement the cylinders are not mounted between the journals as is the case in the former, the cylinders are mounted on the housings. In this arrangement the reaction forces of the cylinder are taken by the housings which means that the housings must be built to resist the additional forces, substantially adding to the expanse of the mill. Of equal importance, when the cylinders are mounted on the housing, which is also true when they are arranged between the journals, the screws of the mill are subject to the total bending forces in addition to the rolling loads.

The present invention provides a crown control system for a rolling mill or like device wherein the reaction forces from the bending cylinders are not imposed upon 3,3ti4,715 Patented Jan. 23, 1968 the housing and wherein the screws of the mill are not subject to any bending forces.

Accordingly, one of the objects of the present invention is to provide, say for example, in connection with a 4-high mill, an independent beam positioned between the screws and the chocks of the upper backup rolls. To this beam there is connected at each end a double piston cylinder assembly, each cylinder being mounted on the mill, one piston thereof being connected to the beam and the other to the end of the roll, the arrangement being such that equal and opposite forces are transmitted to the beam, and as a result no forces are imposed on the housings or the mill screws.

In one form, in connection with a 4-high-mil1, at the top of the mill a beam is arranged between the chocks of the upper backup roll and the screws, and at the bottom of the mill at similar beam is provided which is positioned between the chocks of the backup roll and the housings.

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 4-high mill illustrating one embodiment of the present invention; and

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

With reference to these drawings there is illustrated a 4-high mill comprising two vertically arranged, spacedapart housings 11 and 12, the housings having

customary windows

13 and 14 into which is received a pair of work rolls 1S and 16, each work roll being backed up in turn by a

backup roll

17 and 18, respectively.

As shown best in FIGURE 2, the journals of each roll are received in bearing chocks, the work roll chocks being identified by the number 19 and the backup bearing chocks by the number 20. In the customary manner the work rolls are urged away from each other and against their respective backup rolls by balance piston cylinder assemblies 21 mounted in the lower work roll chocks 19.

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 23 which for brevity reference will be made to only one side of the mill. The lower surface of the beam in the vicinity of the chock 20, is provided with a rocker plate 24 which engages a similar rocker plate 25 formed on the top of the adjacent 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 26, the top of the breaker block having a spherical surface which is engaged by a complementary surface formed at the bottom of the screw 27. The screw 27 is received in a nut 28 formed in the housing 11, the screw being rotated by a worm and wheel not specifically shown on the drawings.

Drawing attention now specifically to the beam 23, as shown in FIGURE 1, the center is connected to a rod 31, which extends in a vertical direction. To the upper end of the rod 31 there is connected a piston 32 of a piston cylinder assembly 33 mounted on a separator 34 that connects the housings 11 and 12 together at the top of the mill. The piston cylinder assembly 33 is employed to urge the chocks against the beam and the beam against the screws. To this end, the beam at its lower end is provided with opposed downwardly extending hooks 35 which cooperate with projections 35a formed at the top of the chocks 20, whereby in operation of the piston cylinder assembly 33 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 36 which, as shown at the left of FIGURE 1, receive two pistons, 37a and 37b, one extending from the top of the cylinder and the other extending from the bottom.

The lower piston 37b engages a rocker plate 38 carried by the beam 23, 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 370, as shown best in FIGURE 2, is connected to a cross member 39, to the ends of which there are connected identically pivotal links 40 which extend downward of the rolls on the outside of the window 13.

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 20, there is provided a second bearing chock 41, which, as shown in FIGURE 2, is provided with opposed projecting horizontal wings 42. The lower ends of the links 4t are formed so as to engage the wings 42 of the bearing chock 41 whereby the bending force exerted by the cylinder 36 through the piston 37a 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.

It will be appreciated that upon the operation of the cylinder 36, a force is imposed upon the beam 23 by the piston 37b in a direction toward the work roll and a force is imposed upon the roll by the piston 37a which imposes a second force upon the beam in a direction opposite from the first force. Moreover, the lever arm effect of these two forces imposed on the beam are equal. Hence, there is a closed force circuit developed whereby not only are there not any reaction forces imposed upon the housings 11 and 12, but the screws 27 are free from any bending forces.

A generally similar arrangement is provided for the lower backup roll 18, in which connection there is a lower beam 45 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 20 of the lower backup roll 13. For completion of the description, it will be noted that the chock 20 is separated from the beam by a series of filler plates 46 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 as to one side of the mill the relationship between the beam 45 and the housing 11, wherein the beam rests upon the housing, there being rocker plates 48 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 49. The cylinder, in referring to one side of the mill, as in the case of the cylinders 36, is provided with two oppositely arranged pistons 51:: and 51b, 51a being the upper piston which engages the lower surface of the beam 45 through a spherical bearing block 52 provided for allowing for relative movement between the beam and the piston 51a. The piston 51b extends downwardly from the cylinder 49 and is connected to a cross member 53, to which are pivotally secured at its outer ends, elongated links 54 extending toward the work roll in such a way as to be clear of the window 13.

Outward of the main bearing chock 20 of the lower backup roll 18 is a second bearing chock 55, the chock of which, as shown in FIGURE 2, has horizontal wings 56 engaged by the links 54 and through which means the bending force of the piston cylinder assembly 49 is applied to the lower roll 18 in a way to bend the central portion of the roll 18 in a direction of the lower work rolls 16. This arrangement, as in the arrangement pro vided for the upper backup roll 17, provides a closed force circuit wherein the piston 51a imposes a force on the beam in one direction and the piston 51b imposes an equal, but opposite force on the beam through the chock 20, whereby the bending forces are self contained and are not imposed upon the housings 11 and 12.

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 has been illustrated in connection with a 4-high mill, it may be used in other types of 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 principle 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 adapted to deflect away from the material being rolled under the rolling loads,

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 between its bearing-chock assemblies and said housing and having portions extending outward of the bearing-chock assemblies of said one roll,

force exerting means for each extending portion of said one roll having displaceable elements connectable to the roll extending portions for imposing bending forces thereon to control the deflection of said one roll,

said force exerting means arranged with respect to said cross member that the reaction of the force exerted to displace said elements is taken by said cross memher and not by said housing.

2. In a rolling apparatus according to claim 1 wherein said cross member includes portions adapted to receive the rolling loads from the bearing-chock assemblies of said one roll and transfer them to said housing.

3. In a rolling mill and like apparatus:

a pair of housings,

windows in said housings,

a pair of working rolls received in said windows,

a backup roll for each work roll received in said windows,

bearing-chock assemblies mounted on the ends of the backup rolls for rotatably supporting the ends of the rolls in said housings,

said backup rolls having portions extending outward of said bearing-chock assemblies,

a cross member for each backup roll arranged parallel to the backup rolls and between their bearing-chock assemblies and said housing and having portions extending outward of their bearing-chock assemblies,

a force exerting means for each extending portion of the backup rolls and having displaceable elements connectable to the roll-extending portions for imposing bending forces thereon,

said force exerting means arranged with respect to said cross members that the reaction of the forces exerted to displace said elements is taken by said cross members and not by said housings.

4. In a rolling mill according to claim 3, wherein the said relationship between the backup rolls and said cross members at the effective application. points of the bending forces and reaction forces is such that the lever arms of the bending forces are equal to the lever arms of the reaction forces.

5. In a rolling mill or like apparatus according to claim 3, including a roll adjusting means carried by said housings for adjusting the vertical position of the uppermost backup roll, the construction being such that the roll adjusting means is not subject to any roll bending forces, and

means for urging the member associated with the uppermost backup roll towards the roll adjusting means.

6. In a rolling mill or like apparatus according to claim 3, wherein said force exerting means comprises piston cylinder assemblies each having two pistons, one piston connected to the end of the backup rolls and the other piston engages with said member.

7. In a rolling mill or like apparatus according to claim 6, wherein each said piston cylinder assembly is located in the same vertical plane containing the axes of the rolls and associated with said means for connecting said force exerting means to said roll ends,

said connecting means including a cross member connected to the pistons employed to apply the bending forces to the backup rolls, and wherein said rolling mill further includes,

a pair of arms having their one end pivotally connected to the outer ends of the cross member, the other ends of said arms having projecting portions, and

projecting portions on said bearing-chock assemblies engageable by said projections of said arms.

References Cited UNITED STATES PATENTS 2,897,538 8/ 1959 Shapiro et al. 72-245 X 3,171,305 3/1965 Stone 72-241 3,212,314 10/1965 Sieger 72-225 3,250,105 5/1966 Stone 72240 CHARLES W. LANHAM, Primary Examiner.

20 A. RUDERMAN, Assistant Examiner.