US3842639A

US3842639A - Side-shifting mill roll

Info

Publication number: US3842639A
Application number: US00371766A
Authority: US
Inventors: A Petros
Original assignee: Mesta Machine Co
Current assignee: MESTA ENGINEERING COMPANY APARTNERSHIP OF PA
Priority date: 1973-06-20
Filing date: 1973-06-20
Publication date: 1974-10-22
Anticipated expiration: 1991-10-22

Abstract

Mill roll changing apparatus for positioning transversely of a rolling mill pass line and arranged for receiving and inserting mill rolls relative to a juxtaposed mill stand comprises a movable floor section normally covering a roll changing pit adjacent the mill stand, a support structure for the floor section and positionable within the pit, and a number of rails on the floor section. Driving mechanism is provided for moving the floor section laterally of the support structure in a direction generally parallel to the mill pass line so that selected pairs of the floor section rails can be laterally aligned with a pair of rails within the mill stand. An elevating mechanism mountable within the pit is structured for elevating the floor section to a first position above an existing floor surrounding the pit so that the floor section can be moved laterally thereof and to a second position whereat the floor section is flush with the existing floor and to a third position whereat the floor section is recessed within the roll-changing pit.

Description

Petros States Patent 91 Oct. 22, 1974 SIDE-SHIFTING MILL ROLL Andrew J. Petros, Oakdale, Pa.

[73] Assignee: Mesta Machine Company,

Pittsburgh, Pa.

[22] Filed: June 20, 1973 [211 Appl. No.: 371,766

[75] Inventor:

Primary Examiner-Milton S. Mehr Attorney, Agent, or Firm-D0nn J. Smith 5 7 ABSTRACT Mill roll changing apparatus for positioning transversely of a rolling mill pass line and arranged for receiving and inserting mill rolls relative to a juxtaposed mill stand comprises a movable floor section normally covering a roll changing pit adjacent the mill stand, a support structure for the floor section and positionable within the pit, and a number of rails on the floor section. Driving mechanism is provided for moving the floor section laterally of the support structure in a di rection generally parallel to the mill pass line so that selected pairs of the floor section rails can be laterally aligned with a pair of rails within the mill stand. An elevating mechanism mountable within the pit is structured for elevating the floor section to a first position above an existing floor surrounding the pit so that the floor section can be moved laterally thereof and to a second position whereat the floor section is flush with the existing floor and to a third position whereat the floor section is recessed within the roll-changing pit.

10 Claims, 5 Drawing Figures SlDE-SHIFTING MILL ROLL The present invention is an improvement upon certain aspects of the roll changing arrangement described and claimed in coassigned U.S. Pat. No. 3,451,244 granted to W. L. Stover et al. The invention is also an improvement over certain roll changing systems illustrated in Mesta Machine Company brochure entitled Mesta Work Roll Changing Systems, copyright 1966.

The present invention relates to a side-shifting mill roll changing system or apparatus, and more particularly to a system of the character'described having novel means for effecting the side-shifting of one of both assemblies of withdrawn and replacement mill rolls.

The system of my present invention enables mill rolls to be changed quickly and efficiently utilizing components of simplified mechanical construction. Although the mill roll changing system is described primarily in connection with the work and back-up rolls of a four high mill stand, it will be evident that the principles of the invention are applicable to other types of rolling mills and other types of roll assemblies. It will also be readily apparent as this description proceeds that the present .roll changing system can be used in conjunction with either hot or cold rolling mills.

Numerous systems have been proposed heretofore for changing mill rolls in various types of rolling mills. For the most part these prior systems have been limited in applicability, have consumed valuable manufacturing space, in many cases have created personnel hazards, and have been unduly and mechanically complicated both from a first procurment point of view as well as for continuing maintenance. Frequently, there are unnecessary losses in production and personnel time during the roll-changing operation.

The conceptualization of the present invention extends considerably the applicability of mechanized roll changing operations to a wide range .of roll sizes and floor line to pass line dimensions. The'roll-changing procedures involved in my present invention are simplified in comparison with previous systems and require fewer mechanical components. Unnecessary complexities in the roll changing apparatus are thereby avoided, and operation and maintenance are considerably improved. The side-shifting technique, upon which my novel roll changing system is based, clears the mill area floor of usual roll changing components and provides a flush floor structure when the roll changing system is not actively in use. In consequence, the overall production time of a given rolling mill is enhanced, and many personnel hazards, such as tripping, are eliminated.

I overcome the disadvantages of the prior art and accomplish the aforementioned desirable results and improvements by providing mill roll changing apparatus for positioning transversely of a rolling mill pass line and-arranged for receiving and inserting mill rolls relative to a juxtaposed mill stand, said apparatus comprising a movable floor section normally covering a roll changing pit adjacent said mill stand, a support structure for said floor section and positionable within said pit, a number of rails on said floor section, driving mechanism for moving said floor section laterally of said support structure in a direction generally parallel to said pass line so that selected pairs of said rails can be laterally aligned with a pair of rails within said mill stand, and an elevating mechanism mountable within 2 said pit and structured for elevating said floor section to a first position above an existing floor surrounding said pit so that said floor section can be moved laterally thereof and to a second position whereat said floor section is flush with said existing floor'and to a third position whereat said floor section is recessed within said pit.

I also desirably provide a similar roll-changing apparatus wherein said pit is elongated in a direction transversely of said mill pass line and extends beneath said existing floor, and guideways are mounted in said pit and beneath said existing floor, said guideways being aligned with the lowermost position of said floor section, and traction means are provided for drawing said floor section and its support along said guideways to a position beneath said existing floor and away from the open area of said pit.

I also desirably provide a similar roll-changing apparatus wherein said pit is shaped to receive a lower backup roll assembly from said mill stand and said traction means are coupled to said lower assembly for drawing said assembly into said pit simultaneously with withdrawal of said floor section and said support to their position beneath said existing floor.

I am aware of a number of previous efforts in this field typified for example by the patents to Simmonds U.S. Pat. No. 3,611,779; Sevenich et al. U.S. Pat. No. 3,695,080; and Eibe U.S. Pat. No. 3,698,226. These patents, however, do not disclose the novel features of the invention as set forth above.

During the foregoing discussion, various objects, features and advantages of the invention have been set forth. These and other objects, features and advantages of the invention together with structural details thereof will be elaborated upon during the forthcoming description of certain presently preferred embodiments of the invention and presently preferred methods of practicing the same.

In the accompanying drawings I have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same, wherein:

FIG. 1 is a side elevational view, partially in vertical section, of one form of roll changing system according to the invention; 1

FIG. 2 is a top plan view of the apparatus shown in FIG. 1;

FIG. 3 is a vertically sectioned view of the apparatus as shown in FIG. 1 but taken along reference lines III- -III thereof;

FIG. 4 is apartial view similar to FIG. 1 but showing the system in a raised operating position; and

FIG. 5 is a view similar to FIG. 1 but showing components of the changing system in a lowered and withdrawn position for back-up roll changing. 7

With reference now initially to FIGS. l3 of the drawings, in greater detail, an exemplary form of my novel mill roll changing system 20 is illustrated therein in connection with a mill stand shown partially at 22 and a replacement work roll assembly 24. The mill stand 22 typically can be a four-high stand, of which the upper backup roll has been omitted for purposes of illustration. The work roll assembly 24' includes a

pair ofwork rolls

26, 28 each of which is provided with a pair of

bearing chocks

30 or 32. The bearing chocks 32 of the lower work roll 28 desirably are provided with

railway trucks

34, 36 respectively for engagement with pairs of rails 38, 40 (FIG. 2) on side-shifting floor plate 42. Depending upon the particular chain-outlined position 44 or 46 (FIG. 2) of the side-shifting plate 42, one pair or the other of the

rails

38, 40 is aligned with upper internal rails 48 of the mill stand 22, and with additional rails (not shown) leading from the side-shifting floor plate 42 to the roll shop.

The mill stand 22 additionally is provided with a lower pair of rails 50 located beneath the work roll rails 48 for reception of the lower back-up roll 52, the bearing chocks 54 of which are likewise provided with railway trucks 56. The work roll assembly 24' located within the mill stand 22 is of course similarly constructed relative to the replacement work roll assembly 24 described briefly above.

The side-shifting floor plate 42 is mounted upon support plate 58 by means of a number of slides or tychoway type bearings or the like denoted generally by the reference character 60. The movable floor plate 42 is shifted between its limit positions denoted by the aforementioned chain-

outlines

44, 46 in FIG. 2 by suitable drive mechanism denoted by reference numeral 62 and slung from the underside of the support blade 58 as better shown in FIGS. 1 and 3. The drive mechanism 62,

in this example including electric motor 64 and reducer 66, are thus mounted for movement with the support plate 58.

Linear motion is transmitted to the floor plate 42 in effecting the aforementioned movements thereof by means of output pinion 68 of the reducer 66, a pair of

idler pinions

70, 72 mounted on common shaft 74 for rotation therewith, and a pair of

gear racks

76, 78 affixed to the underside of the floor plate 42 and enmeshed respectively with the

idler pinions

70, 72. The common shaft 74, as part of the drive mechanism 62, likewise is mounted on the underside of the support plate 58 for movement therewith, for example, by a pair of pillow blocks 80. To prevent exessive loadings upon the bearings 60 and the gear racks 76, 78 particularly in the lateral directions thereof, i.e., longitudinally of the work roll assembly 24, a pair of slides and slideways denoted generally by the referenced numeral 82 are formed cooperatively on the floor plate 42 and the support plate 58 to absorb inertial loadings owing to starting and stopping of the roll assembly 24 or 24' whenever positioned on the side-shifting floor plate 42.

The floor plate 42 and its supporting plate 58 are movable in this example to three elevational positions represented in FIG. 1 by the solid outlines of the

plates

42, 58 and by chain-

outlines

84, 86 thereof. The uppermost or operating position 84 is seen more clearly in FIG. 4.

At the floor level elevation of the side-shifting plate 42 and its support plate 58, as denoted by the solid outlines thereof in FIGS. 1 and 3, the floor plate 42 is flush with the surrounding floor areas of the mill, which areas are denoted by reference numeral 88 (FIG. 3). At this inactive position of the roll changing components the floor plate 42 virtually eliminates any tripping hazard and any obstruction of normal mill activities in or about the roll changing area. In furtherance of this purpose, as evident from FIG. 3, the pairs of

rails

38, 40 desirably are machined into the upper surface of the side-shifting floor plate 42.

As evident from both FIGS. 1 and 3 at the solid outline or floor elevation of the

plates

42, 58 the rails 38,

40 of the side-shifting plate 42 are depressed below the elevation of the upper or work roll mill rails 48. In order to secure alignment of the plate rails 38, 40 with the upper mill rails 48, and to permit lateral shifting of the floor plate 42, the floor plate and its supporting plate 58 are raised to its uppermost elevation 84 (chain outline in FIG. 1, solid in FIG. 4). At this elevation the floor plate 42 can be shifted between its positions 46, 44 (FIG. 2) in order to align first its rails 38 with the upper mill rails 48 for withdrawal of the used work roll assembly 24' onto the rails 38. The drive mechanism 62 is then energized in the opposite direction to align the plate rails 40 at position 44 with the mill stand upper rails 48 so that the placement assembly 24 can be inserted into the mill stand 22.

At the lowermost elevation 86 of the side-shifting floor plate 42 and its supporting plate 58, slide blocks 90 (FIG. 3) are lowered to their chain outline position 92 to rest on slideways 94 of the below floor level foundation structure. At this elevation the entire roll changing system 20 can be withdrawn rearwardly on the slideways 94 as the lower backup roll assembly 52-54 is withdrawn from the mill stand 22 along the mill stand lower rail sections 50 and along a pair of rails 96 aligned therewith in the roll-changing pit 97.

The side-shifting floor plate 42 and its support plate 58 are elevated to the three positions described above by convenient and unexpected elevating means mounted generally beneath the floor opening 98 and within the roll-changing pit 97 (FIGS. 1, 3, and 4). The elevating means are arranged to permit sliding of the support plate 58 thereover, when the support plate 58 and the floor plate 42 thereontogether with the lower backup roll 52 and withdrawn from the mill as shown in FIG. 5. Provision is also unexpectedly made by the present invention for withdrawing both the floor plate 42 and the support plate 58 by the same traction mechanism used in withdrawing and replacing the lower backup roll 52.

In furtherance of this purpose drawbar 100 for the lower backup roll 52 is provided with a pedestal 102 rigidly mounted thereon as best shown in FIGS. 1 and 4. The pedestal 102 is slidably inserted into a generally tubular driving connection 104 secured to the underside of the support plate 58 adjacent the forward end thereof. The sliding connection between the

components

102, 104 allows elevation of the side-shifting floor plate 42 and its support 58 without decoupling from the traction mechanism for the lower backup roll bearing chock 54, including the drawbar 100. Suitable traction means, such as a long stroke piston and cylinder arrangement 106 are coupled to the drawbar 100 for withdrawing and replacing the lower backup roll assembly 52-54 and for simultaneous movements of the side-shifting plate 42 and its support 58 along the slideways 94.

One form of the aforementioned elevating means for the side-shifting floor plate 42 includes a pair of cylinder arrangements 108, 110 (FIGS. 1 and 3) which are pivotally mounted on, and suspended between, respective pairs of

abutments

112, 114. A pair of the

cylinder arrangements

108, 110 and associated components are utilized such that the driving mechanism 62 for the laterally shifting floor plate 42 can pass therebetween as evident from FIG. 3.

Each of the

cylinder arrangements

108, 110 in this example includes first and

second cylinders

116, 118 of which the cylinder 116 is of relatively longer stroke and the cylinder 118 is of relatively shorter stroke. In other spatial arrangements of the invention it is conceivable that the strokes of the

pistons

116, 118 can be the same or that the stroke ralationship can be reversed. in the illustrated example, the distal end 120 of each pistoncylinder arrangement 116 is pivoted to the associated forward abutment 112 while distal ends 122 of the shorter stroke piston-cylinders 118, are pivoted respectively to cranks 124 which in turn are pivoted by means of fulcrum pins 126 to the rear abutments 114.

Similarly positioned cranks 128 are likewise pivoted at 130 to the forward abutments 112 respectively and are slaved to the rearward cranks 124 through pivoted linkages 132. At the points of their contact with the underside of the support plate 58, the

cranks

124, 128 are provided with rollers to reduce frictional engagement, particularly when the supporting plate 58 and the floor plate 42 thereon are moved between the forward and rearward positions thereof, as shown respectively in FlGS. l and 5. At the lowermost position of the roll changing components (chain-outline 86, FIG. 1) the forward rolls of the

cranks

124, 128 are aligned with the slideways 94 such that the support plate 58 first rolls along the

cranks

124, 128 and then engages the slideways 94 by virtue of the aforementioned slide blocks 90 affixed to the underside of the support plate 58.

Following on from the earlier operational description of the side-shifting plate 42, the operation of the remainder of the roll-changing components, including the elevational means, will now be described. In the solid outline positions of the elevating means 110 (FIG. 1) the longer stroke cylinders 116 have been fully extended to position the

cranks

124, 128 at their solid outline position corresponding to the intermediate or inactive, floor level position of the side-shifting floor plate 42. Whenever it is desired to align the floor plate rails 38 or 40 with the upper mill rails 48 the smaller stroke cylinders 118 are likewise extended (while the longer stroke cylinder 116 are maintained in their extended condition) to move the rear cranks 124 to their chain outline positions 130 (the front crank 128 are similarly moved) at which positions the rear rollers 132 thereof contact the underside of. support plate 58 to move both the support plate 58 and the floor plate 42 to the uppermost or chain outline position 84 thereof. On the other hand to permit withdrawal of the lower backup roll 54 both of the

cylinders

116, 118 are fully retracted to move the rear cranks 124 to their chain outline position 134 at which point their front rollers 136 are engaged with the underside of the support plate 58 (as in the intermediate or solid outline position thereof) and in addition are aligned with the slideways 94 as aforesaid. The front cranks 128 are moved to similar positions corresponding to the chain outline positions 130, 134 of the rear cranks 124 by means of the linkages 132.

The divided nature of the elevating means including the cylinder arrangement 110 permits the lower backup roll assembly to be moved therebetween. In consequence it is not necessary to withdraw the aforementioned elevating means with the remaining components of the roll changing system 20. Upon operation of the traction means 106 such remaining components, by virtue of their sliding connection 102-104 with the drawbar 100, are moved to the rear or away from the mill stand 22 along with the lower backup roll assembly 52. When the backup roll assembly has been fully withdrawn, the movable components of the roll changing apparatus 20, including the floor plate 42 and its support plate 58 are moved entirely beneath the fixed floor area 88 as shown in FIG. 5. The latter roll changing components are thus moved to a position of minimal interference with other mill activities, including removal and replacement of the lower backup roll, and also are fully protected by the overlying floor structure From the foregoing it will be seen that a novel and efficient side-shifting mill roll changing system has been described herein. The descriptive and illustrative materials employed herein are utilized for purposes of exemplifying the invention and not in limitation thereof. Accordingly, numerous modifications of the invention will occur to those skilled in the art without departing from the spirit and scope of the invention. Moreover, it is to be understood that certain features of the invention can be used to advantage without a corresponding use of other features thereof.

I claim:

1. Mill roll changing apparatus for positioning transversely of a rolling mill pass line and arranged for re ceiving and inserting mill rolls relative to a juxtaposed mill stand, said apparatus comprising a movable floor section normally covering a roll changing pit adjacent said mill stand, a support structure for said floor section and positionable within said pit, a number of rails on said floor section, driving mechanism for moving said floor section laterally of said support structure in a direction generally parallel to said pass line so that selected pairs of said rails can be laterally aligned with a pair of rails within said mill stand, and an elevating mechanism mountable within said pit and structured for elevating said floor section to a first position above an existing floor surrounding said pit so that said floor section can be moved laterally thereof and to a second position whereat said floor section is flush with said existing floor and to a third position whereat said floor section is recessed within said pit.

2. The combination according to claim 1 wherein said floor section rails are machined into the surface thereof. t

3. The combination according to claim 1 wherein said driving mechanism is mounted on said support structure for movement therewith.

4. The combination according to claim 1 wherein said elevating mechanism includes at least one pair of piston-cylinder arrangements mounted back to back.

5. The combination according to claim I wherein said pit is elongated in a direction transversely of said mill pass line and extends beneath said existing floor, and guideways are mounted in said pit and beneath said existing floor, said guideways being aligned with the lowermost position of said floor section, and traction means are provided for drawing said floor section and its support along said guideways to a position beneath said existing floor and away from the open area of said pit.

6. The combination according to claim 5 wherein said pit is shaped to receive a lower backup roll assembly from said mill stand and said traction means are coupled to said lower assembly for drawing said assembly into said pit simultaneously with withdrawal of said 9. The combination according to claim 8 wherein said elevating means include a pair of elevating mechanisms spaced laterally of one another and of the central area of said pit in order to accommodate passage of said driving mechanism therebetween.

10. The combination according to claim 1 wherein said driving mechanism includes rack and pinion means mounted on said floor section and support structure and extending generally parallel to said mill pass line.

Claims

1. Mill roll changing apparatus for positioning transversely of a rolling mill pass line and arranged for receiving and inserting mill rolls relative to a juxtaposed mill stand, said apparatus comprising a movable floor section normally covering a roll changing pit adjacent said mill stand, a support structure for said floor section and positionable within said pit, a number of rails on said floor section, driving mechanism for moving said floor section laterally of said support structure in a direction generally parallel to said pass line so that selected pairs of said rails can be laterally aligned with a pair of rails within said mill stand, and an elevating mechanism mountable within said pit and structured for elevating said floor section to a first position above an existing floor surrounding said pit so that said floor section can be moved laterally thereof and to a second position whereat said floor section is flush with said existing floor and to a third position whereat said floor section is recessed within said pit.

2. The combination according to claim 1 wherein said floor section rails are machined into the surface thereof.

5. The combination according to claim 1 wherein said pit is elongated in a direction transversely of said mill pass line and extends beneath said existing floor, and guideways are mounted in said pit and beneath said existing floor, said guideways being aligned with the lowermost position of said floor section, and traction means are provided for drawing said floor section and its support along said guideways to a position beneath said existing floor and away from the open area of said pit.

6. The combination according to claim 5 wherein said pit is shaped to receive a lower backup roll assembly from said mill stand and said traction means are coupled to said lower assembly for drawing said assembly into said pit simultaneously with withdrawal of said floor section and said support to their position beneath said existing floor.

7. The combination according to claim 5 wherein said support structure is coupled to said traction means through a sliding pedestal and sleeve arrangement so that said support structure and said floor section remain coupled to said traction means irrespective of the elevation thereof.

8. The combination according to claim 5 wherein said driving mechanism is mounted on the underside of said support structure for movement therewith.

9. The combination according to claim 8 wherein said elevating means include a pair of elevating mechanisms spaced laterally of one another and of the central area of said pit in order to accommodate passage of said driving mechanism therebetween.