ROLLING MILL STANDS

Abstract: A rolling mill stand has a pair of work rolls which are movable axially. Actuators mounted on the mill housing are engageable and disengageable with the roll chock assemblies of the work rolls and, when they are engaged in latching relation, one part of the actuator is moved in one direction to axially displace one of the rolls in one direction and another part of the actuator is moved in the opposite direction to axially displace the other roll in the opposite direction.

Description: ROLLING MILL STANDS This invention relates to rolling mill stands and, in particular, to means for axially displacing one or more of ; ' the rolls of the mill stand. It is sometimes desirable that a roll, usually a work roll, can be displaced axially relative to a co-operating roll and very often it is desirable that a pair of co-operating rolls, such as work rolls, should each be moved axially, but in opposite directions, in order to provide a limited axial displacement between the two co-operating rolls. Furthermore, it is sometimes desirable that an existing rolling mill stand, which does not have the facility for axial movement of its rolls, should be readily modified so that this facility can be provided. According to a first aspect of the invention, a rolling mill stand comprises a housing; at least two rolls each rotatably mounted at its ends in respective bearing chock assemblies which are supported in the housing; and actuator means ' mounted on the housing and including a latch displaceable in a first direction, and means for displacing the latch in a second direction into and out of latching arrangement with the chock assembly at one end of one of the rolls whereby displacement of the latch in the first direction when it is in latching arrangement with the chock assembly causes the chock assembly and the roll to be moved relative to the mill housing in the axial direction of the roll. The actuator means has to have the facility for withdrawing the latch from latching arrangement with the chock assembly so that the chock assembly and the roll can be withdrawn from the mill housing at roll change time. An existing mill which does not have the facility of moving one of its rolls can be provided with the actuator means whereby the latch can be displaced into and out of latching arrangement with a modified chock assembly at one end of one of the rolls whereby displacement of the latch in its first direction when it is latching arrangement with the chock assembly causes the chock assembly and, hence, the roll to be be moved relative to the mill housing in the axial direction of the roll. In a convenient embodiment of the invention, the actuator means includes apart fixed to the housing, the latch which is slidable with respect to the fixed part in the second direction, and a double- acting piston-cylinder device for sliding the latch relative to the fixed part in the second direction. The latch is conveniently slidable along a shaft carried by the fixed part and the latch is also pivotable about the shaft and the actuator means includes piston-cylinder means for pivoting the latch about the shaft, said pivoting movement providing movement of the latch in the first direction. It is desirable, however, that both work rolls should be displaced axially but in opposite directions and, to this end, according to a second embodiment of the invention, a rolling mill stand comprises a housing; a pair of horizontal work rolls arranged one above the other and each supported at their ends in bearing chock assemblies; and actuator means mounted on the housing and including a latch structure displaceable in a first direction and means for displacing the latch structure in a second direction into and out of latching arrangement with the chock assemblies at a corresponding end of the work rolls whereby displacement of the latch structure in the first direction when it is in latching arrangement with the chock assemblies causes one chock assembly and the roll suppported therein to be moved relative to the mill housing in one axial direction of the roll and the other chock assembly and the roll supported therein to be moved relative to the mill housing in the opposite axial direction of the roll. In order that the invention may be more readily understood, it will now be described, by way of example only, with reference to the accompanying drawings, in which:- Figure 1 is a schematic horizontal plan view of part o -a rolling mill stand; Figure 2 is an elevation, partly in section, of an actuator for axially displacing a pair of work rolls; Figure 3 is a sectional side elevation of the apparatus shown in Figure 2 taken on the line III-III; and Figure 4 is a sectional plan view on the line IV-IV. Referring to Figure 1, a work roll 1 of a rolling mill has its usual neck portion 3 at each end, with each neck portion rotatably mounted in a bearing chock assembly 5 of which one is shown in Figure 1. This bearing chock assembly is vertically slidable in a window defined by a massive mill housing 7. The neck portion 3 of the roll has an axial extension 9 of reduced diameter and this, in turn, is rotatably mounted in a bearing chock assembly 11 located outside the mill housing. The chocks 11 and 5 may be integral. The additional chock 11 has a pair of vertical slots 13 formed in it on opposite sides of the axis of the roll. On the outside vertical walls of the housing 7, a pair of actuators 15 are positioned for axially displacing the roll 1. In Figure 1, only one of these actuating devices is illustrated, the other being similar. The actuating device has to be able to displace the roll 1 to a limited extent in its axial direction by sliding the chock 5 relative to the housing 7, but the acutating device has to be disengageable from the roll and its chocks so that, at roll changing, the roll, its chock assemblies 5, and the additional chock assembly 11 can be withdrawn as a unit from the mill housing. Each actuating device 15 is shown in more detail in Figures 2 to 4 and consists of a block 17 which can be removably bolted to the end wall of the housing 7. This block rotatably supports a pivot pin 21 which is arranged substantially horizontal. Pivotally mounted on this pin is a latch in the form of a yoke 23 which has a pair of limbs 25, one of which is located between the block 17 and the slot 13 in the chock 11. The block 17 has at least one cylinder 27 containing a double-acting piston 28 which protrudes rom opposite ends of the block and bears against the opposite limbs of the yoke. By introducing fluid under pressure into one part or other of each cylinder, the piston therein can be caused to project from one end or other of the block to slide the yoke 23 towards and away from the vertical slot 13 in the additional chock. The limb 25 of the yoke which is adjacent the roll carries a roller 29 which is introduceable into and out of the slot 13. When the roller is withdrawn from the slot, the roll 1 with its bearing chock assemblies can be displaced axially out of the mill housing in the normal way for roll changing but, when the roller 29 is introduced into the slot 13, it is in latching arrangement with the chock and sideways movement of the roller will cause limited axial movement of the roll within the housing. A front plate 31 forming part of the yoke 23 overlies four piston-cylinder devices 33 located in the block 17, two of them being above the axis of the pin 21 and two below this axis. When the piston-cylinder devices 33 above the pin 21 are energised, their pistons abut against the inner surface of the front plate 31 and pivot the yoke about the pin in a clockwise direction, causing the roller 29 to have a component of movement in the right- hand direction, as shown in Figure 1. Similarly, when the pistons below the pin 21 are energised, they bear against the inside surface of the front plate and cause the yoke to pivot in an anti-clockwise direction, thus providing a component of movement to the roller 29 which is to the left, as shown in Figure 1. By selectively energising the pistons, the yoke can be caused to pivot about the pin 21, thus displacing the roll 1 by a limited extent in its opposite axial directions. It is usual for both work rolls of a rolling mill to be moved axially simultaneously but to be moved in opposite directions. In this way, the two rolls are arranged one above the other and the slots 13 in the additional chock 11 on one roll are vertically aligned with the vertical slots in the additional chock on the lower work roll. The yoke 23 carries a pair of rollers 29, (see Figure 2), one above the axis of the pin 21 and one below this axis, and the two rollers engage in the respective vertical slots. As the yoke is pivoted, one roller moves in a clockwise direction while the other moves in an anti-clockwise direction, causing one roll to be moved axially in one direction by a limited extent and the other roll to be moved axially in the opposite direction by the same extent. A transducer 35 connected between the block 17 and the yoke gives an electrical indication of the .position of the yoke and, hence, the axial position of the roll.

Claims: Claims : 1. A rolling mill stand comprising a housing; at least two rolls each rotatably mounted at its ends in respective bearing chock assemblies which are supported in the housing; and actuator means mounted on the housing and including a latch displaceable in a first direction, and means for displacing the latch in a second direction into and out of latching arrangement with the chock assembly at one end of one of the rolls whereby displacement of the latch in the first direction when it is in latching arrangement with the chock assembly causes the chock assembly and the roll to be moved relative to the mill housing in the axial direction of the roll. 2. A rolling mill stand as claimed in claim 1, in which the actuator means includes a part fixed to the housing, the latch which is slidable with respect tp the fixed part in the second direction and a double- acting piston-cylinder device for sliding the latch relative to the fixed part in the second direction. 3. A rolling mill stand as claimed in claim 2, in which the latch is slidable along a shaft carried by the fixed part and the latch is also pivotable about the shaft and the actuator means includes piston- cylinder means for pivoting the latch about the shaft, said pivoting movement providing movement of the latch in said first direction. 4. A rolling mill stand comprising a housing; a pair of horizontal work rolls arranged one above the other and each supported at their ends in bearing chock assemblies; and actuator means mounted on the housing and including a latch structure displaceable in a first direction and means for displacing the latch structure in a second direction into and out of latching arrangement with the chock assemblies at a corresponding end of the work rolls whereby displacement of the latch structure in the first direction when it is in latching arrangement with the chock assemblies causes one chock assembly and the roll suppported therein to be moved relative to the mill housing in one axial direction of the roll and the other chock assembly and the roll supported therein to be moved relative to the mill housing in the opposite axial direction of the roll. 5. A rolling mill stand as claimed in claim 4, in which the actuator means comprises a part fixed to the housing, a horizontal shaft carried by the fixed part, said latch structure being displaceable along the shaft in said second direction and also rotatable about said shaft, double-acting piston-cylinder means for sliding the latch structure along the shaft, said structure having first and second latches positioned above and below the shaft, respectively, which are engageable with a chock assembly of the upper and lower work rolls, respectively; and piston-cylinder means for pivoting the latch structure about said shaft, said pivoting movement causing the first and second latches to be displaced in opposite directions. 6. A rolling mill stand as claimed in any preceding claim, in which the or each latch is introduced into a slot in the bearing chock assembly to constitute a latching arrangement therewith, said slot extending transverse to said first direction.

Inventors: HOBSON DAVID, PEARSON WILLIAM JAMES, HOBSON, DAVID, PEARSON, WILLIAM, JAMES
Applicants: DAVY MCKEE POOLE, DAVY MCKEE (POOLE) LIMITED
Application year: 1986
Main classification: B21B31
IPC codes: B21B31