US3603125A

US3603125A - Automatic control system for means for removing roll coating from a rolling mill work roll without removing the roll from the mill

Info

Publication number: US3603125A
Application number: US826240A
Authority: US
Inventors: Joseph N Edwards
Original assignee: Reynolds Metals Co
Current assignee: Reynolds Metals Co
Priority date: 1969-05-20
Filing date: 1969-05-20
Publication date: 1971-09-07
Anticipated expiration: 1988-09-07

Abstract

In a rolling mill having rolls for acting on work passing between the rolls and means for removing coating which tends to accumulate on the rolls, means mounting the coating removing means for shifting movement between operative position in contact with a roll and inoperative withdrawn position and means, which may include control means actuated by entry of the leading end of the work between rolls of the mill, responsive to the position of the leading end of the work for shifting the coating removing means to operative position. The structure may include operating means actuated in response to the position of the trailing end of the work for shifting the coating removing means to inoperative position, desirably before the work leaves the roll. The invention may be employed in a rolling mill having in tandem a plurality of stands of rolls for acting on work passing between the rolls of the successive stands, means for removing mounting coating which tends to accumulate on the rolls and means mounting the coating removing means for shifting movement between operative position in contact with a roll of one of the stands of rolls and inoperative withdrawn position, and may include means responsive to the position of the leading end of the work for shifting the coating removing means to operative position, which may include control means actuated by entry of the leading end of the work between rolls of the first mentioned stand, and operating means actuated by passage of the trailing end of the work from between rolls of a stand of rolls traversed by the work before the work traverses the first mentioned stand of rolls for shifting the coating removing means to inoperative position. The control means and/or the operating means may include load cell, pressductor or current relay means.

Description

iinited States Patent [72] Inventor Joseph N. Edwards Brookfield, Ill. [21 1 Appl. No 826,240 [22] Filed May 20, 1969 [45] Patented Sept. 7,1971 [73] Assignee Reynolds Metals Company Richmond, Va.

[54] AUTOMATIC CONTROL SYSTEM FOR MEANS FOR REMOVING ROLL COATING FROM A ROLLING MILL WORK ROLL WITHOUT REMOVING THE ROLL FROM THE MILL Primary Examiner-Charles Lanham Assistant Examiner-E. M. Combs Attorney-Glenn, Palmer, Lyne, Gibbs & Thompson ABSTRACT: In a rolling mill having rolls for acting on work passing between the rolls and means for removing coating which tends to accumulate on the rolls, means mounting the coating removing means for shifting movement between operative position in contact with a roll and inoperative withdrawn position and means, which may include control means actuated by entry of the leading end of the work between rolls of the mill, responsive to the position of the leading end of the work for shifting the coating removing means to operative position. The structure may include operating means actuated in response to the position of the trailing end of the work for shifting the coating removing means to inoperative position, desirably before the workleaves the roll. The invention may be employed in a rolling mill having in tandem a plurality of stands of rolls for acting on work passing between the rolls of the successive stands, means for removing mounting coating which tends to accumulate on the rolls and means mounting the coating removing means for shifting movement between operative position in contact with a roll of one of the stands of rolls and inoperative withdrawn position, and may include means responsive to the position of the leading end of the work for shifting the coating removing means to operative position, which may include control means actuated by entry of the leading end of the work between rolls of the first mentioned stand, and operating means actuated by passage of the trailing end of the work from between rolls of a stand of rolls traversed by the work before the work traverses the first mentioned stand of rolls for shifting the coating removing means to inoperative position. The control means and/or the operating means may include load cell, pressductor or current relay means.

PATENTEU SEP 7197! 3,603,125

SHEET 1 BF 2 f W JOSEPH N. EDWARDS INVENTOR HIS ATTORNEYS am, um ma W PATENTED SEP 71am SHEET 2 BF 2 MS '2 CONTACTS HIS ATTORNEYS AUTOMATIC CONTROL SYSTEM FOR MEANS FOR REMOVING ROLL COATING FROM A ROLLING MILL WORK ROLL WITHOUT REMOVING TI-IE ROLL FROM THE MILL This invention relates to an automatic control system for means for removing roll coating from a rolling mill work roll without removing the roll from the mill.

It has been proposed to provide means for removing or dislodging roll coating from a rolling mill work roll without removing the roll from the mill. The roll-coating removing or dislodging means may be mounted for shifting movement between operative position in contact with a roll and inoperative withdrawn position. Such means are preferably rotating means which may be driven so that when they are in operative position in contact with the roll they engage and dislodge the roll coating. While the roll-coating removing or dislodging means employed in the present invention may assume a wide variety of forms, such means in a preferred form comprise flexible elements and means for mounting the flexible elements for flailing action so that portions of the elements adjacent the ends thereof engage the surface of the roll together with abrasive particles rubbed over the surface of the roll by the flailing action of the flexible elements. Also means may be provided for catching and carrying or flushing away the dislodged roll coating.

I provide an automatic control system for shifting the coating removing means between operative and inoperative positions. My automatic control system shifts the coating removing means in response to the position of the work in the mill. It may comprise means responsive to the position of the leading end of the work. for shifting the coating removing means to operative position. Such means may include control means actuated by entry of the leadingend of the work. between rolls of the mill. The automatic controlsystem may include operating means actuated in response to the position of the trailing end of the work for shifting the coating removing means to inoperative position. Such shifting of the coating removing means to inoperative position desirably occurs before the workv leaves the roll so that a limited controlled thickness of roll coating is allowed to adhere to the roll to promote gripping of the work. If the roll is completely free of roll'coating when the leading end of the succeeding workpiece is engaged by the roll, slippage may occur between the roll and the work impairing adequate gripping of the work. The time when the coating removing means is shiftedto inoperative position is controlled to permit. adherence to the rollof an optimum thickness of roll coating which is maintained below the thickness which would promote sloughing off of roll coating onto the work.

My invention is applicable to a single-stand reversing mill and also to a mill having in tandem a plurality of stands of rolls for acting on work passing between the rolls of the successive stands. In a tandem mill I provide means mounting the coating removing means for shifting movement between operative position in contact with a roll of one of the stands of rolls and inoperative withdrawn position, means responsive to the position of the leading end of the work for shifting the coating removing means to'operative position and operating means actuated by passage of the trailing end of the work from between rolls of a stand of rolls traversedby the work before the worktraverses the first mentioned stand of rolls for shifting the coating removing means to inoperativeposition. The.

means responsive to the position of the leading end of the work for shifting the coatingremovingmeans to operative position may include control means actuated by entry of the leading end of the work between rolls of the first mentioned stand.

The control means and/or the operating means may includeload cell, pressductor or current relay means.

Other details, objects and advantages of the invention will become apparent as the following descriptionof a present preferred embodiment thereof proceeds.

In the accompanying drawings l have shown a present preferred embodiment of the invention in which FIG. 1 is a diagrammatic elevational view of a tandem mill having my invention applied thereto;

FIG. 2 is an enlarged view partly in elevation and partly in vertical cross section of the upper portion of the left-hand stand of rolls in FIG. 1;

FIG. 3 is an enlarged elevational view, largely diagrammatic, of a portion of the structure shown in FIG. 1 and showing elements of the structure which do not appear in FIG. I because of the relatively small scale of that figure; and

FIG. 4 is a diagram of one form of electrical circuitry which may be employed in the application of my invention.

Referring now more particularly to the drawings, there is shown in FIG. 1 a tandem hot rolling mill having two roll stands designated respectively by the numerals l and 2. The

roll stands may be conventional except for the application of my invention thereto and it is unnecessary to describe in detail conventional elements thereof. Each of the roll stands in the form shown is a 4-high roll stand having relatively small work rolls W and relatively large backing up rolls B. Each of the roll stands has the usual housing 3 and screwdown 3a. The work, designated S, passes through the mill from left to right in the direction of the arrow in FIG. 1.

Mounted in the mill housing 2 are parallel horizontal pivots 4 and S. A lever 6 is mounted intermediate its ends on the pivot 4 and a link 7 is mounted at its upper end on the pivot 5. The lever 6 and the link 7 are parallel. The lever 6 is pivoted at its lower end at 8 to a bracket 9 and the link 7 is pivoted at its lower end at 10 to the bracket 9. The distance between the

pivots

4 and 8 is equal to the distance between the pivots 5 and 10 so that the lever 6 and link 7 form a parallelogram mounting structure for the bracket 9 capable of swinging the bracket toward and from the rolls of the mill while maintaining its orientation. The operative position of the bracket 9 and its associated mechanism is shown in solid lines in FIG. 3 and the withdrawn inoperative position is shown in broken lines. Shifting of the parallelogram mounting structure between operative and inoperative positions is accomplished by a pistonin a cylinder 11 pivoted at 12 to a portion of the mill housing and the piston rod of which is pivoted at13 to the upper end of the lever 6. When the mechanism is to be moved to the broken line withdrawn inoperative position fluid under pressure is admitted to the left hand or upper end of the cylinder 11, and when the mechanism is to be moved to the solid line operative position fluid under pressure is admitted to the right hand or lower end of the cylinder 11. Movement toward operative position is limited by a stop member in the form of a screw or bolt 14 threaded through a nut 15 mounted on the housing. A solenoid operated valve (not shown in FIG. 3but designated SV-2 in the electrical circuitry diagram FIG. 4) controls the flow of fluid to the cylinder 11.

The bracket 9 is rigidly connected with a mounting member 16 carrying a cylinder 17 in which operates a piston having a piston rod 18 carrying at its extremity a plate 19. The plate 19 in turn carries an extension 20 in which is journaled for rotation a shaft 21. The shaft 21 carries means for dislodging coating from the upper work roll W when the shaft 21 is driven. Such means in the form shown comprise flexible sheets 22 which are mounted in groups and secured by their edges to a generally cylindrical elongated member 23 in the form of a slotted hub through which the shaft 21 passes; The hub 23 is keyed to the shaft 21 to rotate therewith. The shaft 21 projects beyond both ends of the hub 23 and is journaled in the extension 20.

Movement'of the plate 19 and extension 20 toward the upper work roll W by operation of the piston in the cylinder 17 is limited by a bolt 24 passing through a hole in a projection 25 carried by the mounting member 16 and having nuts 26 threaded thereon as shown in FIG. 3. When the mechanism is in operative position and the shaft 21 is driven the action of the sheets 22 on the working surface of the upper work roll W is a rubbing, wiping or slapping action which is perhaps best described by the adjective flailing" in contradistinction to brushing action by the ends of brush bristles. The sheets 22, which extend lengthwise of the roll in contradistinction to a brush bristle which terminates in a point, have their end surface portions for a short distance back from the end edges of the sheets drawn over the roll surface, the rapid succession of sheets thus acting on the roll surface effectively dislodging and removing coating from the roll surface.

The sheets 22 may be of any suitable material such as paper, cloth or plastic. The sheets must be flexible to have the desired flailing action. Abrasiye particles, such as grit or sand, are rubbed over the roll surface by the flailing action of the sheets. The abrasive particles may be supplied separately, but I prefer that they becarried by the sheets, like sandpaper or emery cloth. The result of such employment of the flexible sheets to flail the working surface of the work roll is the effective removal or dislodging of coating from such surface. This has previously been proposed. My invention is concerned with the automatic control system for the coating removing means. While I prefer the employment of flailing means as above described other means may be employed for dislodging or removing the roll coating.

Mounted on the mill housing is a motor 27 whose shaft 28 carries a sprocket 29. In line with the sprocket 29 is a sprocket 30 fixed to the shaft 21. A sprocket drive chain 31 is trained about the

sprockets

29 and 30 and drives the shaft 21 when the motor 27 is in operation. The drive chain is maintained taut by a pressure roller 32 carried by a piston rod 33 connected with a piston in a vertical cylinder 34, the roller being urged downwardly against the drive chain by fluid pressure in the cylinder.

The coating removing or dislodging means may be moved between operative and inoperative positions as above described, but when such means are to be rendered temporari- 1y inoperative the mounting member 16 carrying the dislodging means and housing may be withdrawn but a short distance (an inch or two) away from the mill rolls while the shaft 21 continues to be driven by the motor 27. The drive chain 3l will be maintained. taut by the pressure roller 32. Thus the dislodging means and housing may be rendered operative and inoperative at will while the dislodging means are continuously driven. Provision may be made for axial oscillation of the dislodging means when the dislodging means are being driven to insure against longitudinal streaking of the work. When such provision is made the dislodging means will continue to oscillate whether such means are in operative or inoperative position so long as they are being driven. Oscillation may be effected by a piston connected with the dislodging means operating in a cylinder the flow of fluid to which is controlled by valves operated by solenoids SV-2E and SV-ZW, FIG. 4.

When rolls are to be changed or the mill shut down the dislodging means and housing will be completely withdrawn to the broken line position of FIG. 3 and the motor 27 will be stopped. When the dislodging means and housing are in that withdrawn inoperative position with the motor stopped the chain will sag between the

sprockets

29 and 30, but since the motor will not be in operation the sagging of the chain presents no disadvantage.

. FIG. 3 shows the coating removing means applied only to the upper work roll W of the roll stand 2 but similar means may be and preferably are applied also to the lower work roll W. In such case a single control system will suffice for both.

Referring to Fig. 2, the roll stand 1 is shown as having a load cell 35 interposed between the screwdown 3a and the upper roll chock 36 which is energized when the leading end of a workpiece enters between the work rolls W of the roll stand 1 and is deenergized when the trailing end of the workpiece passes out from between the rolls toward the roll stand 2. The roll stand 2 is provided with a similar load cell. In place of load cells, pressductors or current relays may be employed.

Referring now to the diagram FIG. 4, a ll-volt, 60-cycle electrical circuit as indicated may supply the current to operate the automatic control system. The contacts LC-2 of the load cell on roll stand 2 control the current to a relay MS- 2. There is also a manual on-off selector switch SW in series with the contacts L'C--2 and the relay MS-2 as shown together with contacts UV of an under voltage relay which are closed in normal running condition of the mill. The under voltage relay serves as a safety feature to automatically disconnect the power to the automatic control system even though the manual on-off switch remains closed.

When the leading end of the work enters roll stand 2 the load cell LC--2 is energized actuating relay MS-2 which closes contacts MS-2 in the second horizontal circuit of FIG. 4 which then actuates the solenoid valve SV-'2 to move the coating removing means to engage the upper work roll W of roll stand 2 if the contacts LC-l of the load cell on roll stand 1 are also closed. The contacts LC-l open when the work leaves roll stand 1 so as to deenergize solenoid valve SV 2 and retract the coating removing means before the trailing end of the work leaves roll stand 2.

Line voltage is continuously applied across the third (lowermost) horizontal circuit in FIG. 4 to keep the coating removing means oscillating (and it is also kept rotating) whether in retracted or engaged position. The contracts A and B control oscillation of the coating removing means. An electric timing relay (not shown) alternately closes and opens these contacts (A being shown in open condition and B in closed condition to pass current to solenoid valve SV2W). This causes traverse of the coating removing means in one direction for a preset period of time, after which contacts B are opened and A are closed and the direction of oscillation of the coating removing means is reversed. As above explained the SV-2E and SV- 2W solenoid valves control delivery of fluid to the cylinder for oscillating the coating removing means.

The functions performed by the load cell, pressductor or current relay means in the roll stands may be performed by means separate from the roll stands, such as photocell or mechanical switch means. Such means have especial utility when the invention is applied to a single-stand reversing mill. In that case a remote switch or photocell on one side of the mill may be used to detect the trailing end of the work as it ap proaches the mill from that side and thereby disengage the coating removing means. A similar switch or photocell on the other side of the mill serves a comparable purpose for movement of the work in the opposite direction. With such an arrangement there is no need for a load cell or the like in the mill itself because the switch or photocell on the side of the mill from which the work is being discharged can be used to detect the leading end of the work as it leaves the mill and thereby engage the coating removing means.

While I have shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

I claim:

1. In a rolling mill having rolls for acting on work passing between the rolls and means for removing coating which tends to accumulate on the rolls, means mounting the coating removing means for shifting movement between an operative position in contact with a roll and an inoperative withdrawn position and means responsive to the position of the leading end of the work for shifting the coating removing means to said operative position.

2. Structure as defined in claim I in which the last mentioned means include control means actuated by entry of the leading end of the work between rolls ofthe mill.

3. Structure as defined in claim 2 in which the control means include load cell, pressductor or current relay means.

4. Structure as defined in claim 1 including operating means actuated in response to the position of the trailing end of the work for shifting the coating removing means to inoperative position.

5. Structure as defined in claim 1 including operating means actuated in response to the position of the trailing end of the work for shifting the coating removing means to inoperative position before the work leaves the roll.

6 Structure as defined in claim 5 in which the control means and operating means include load cell, pressductor or current relay means.

7. In a rolling mill having in tandem a plurality of stands of rolls for acting on work passing between the rolls of the successive stands and means for removing coating which tends to accumulate on the rolls, means mounting the coating removing means for shifting movement between an operative position in contact with a roll of one of the stands of rolls and an inoperative withdrawn position, means responsive to the position of the leading end of the work for shifting the coating removing means to said operative position and operating means actuated by passage of the trailing end of the work from between rolls of a stand of rolls traversed by the work before the work traverses the first mentioned stand of rolls for shifting the coating removing means to said inoperative position.

8. Structure as defined in claim 7 in which the means responsive to the position of the leading end of the work for shifting the coating removing means to operative position include control means actuated by entry of the leading end of the work between rolls of the first mentioned stand.

9. Structure as defined in claim 8 in which the control means include load cell, pressductor or current relay means.

10. Structure as defined in claim 9 in which the operating means include load cell, pressductor or current relay means.

Claims

2. Structure as defined in claim 1 in which the last mentioned means include control means actuated by entry of the leading end of the work between rolls of the mill.

6. Structure as defined in claim 5 in which the control means and operating means include load cell, pressductor or current relay means.