US3583195A

US3583195A - Roll changing apparatus

Info

Publication number: US3583195A
Application number: US793783*A
Authority: US
Inventors: William George Sherwood
Original assignee: Gulf & Western Ind Prod Co
Current assignee: BLISS-SALEM Inc A CORP OF
Priority date: 1969-01-24
Filing date: 1969-01-24
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08
Also published as: DE2003166A1; FR2029076A1

Abstract

Apparatus for removing work-roll and backup roll sets from fourhigh rolling mills. The disclosed apparatus includes a rotatable platform positioned adjacent a mill stand and arranged for selective horizontal rotation and/or elevation. Additionally, there is disclosed a mill stand provided with means for shifting rolls and roll sets vertically to facilitate changing.

Description

United States Patent lnventor William George Sherwood Salem, Ohio Appl. No. 793,783 Filed Jan. 24, 1969 Patented June 8, 1971 Assignee Gulf 8: Western industrial Products Company Grand Rapids, Mich.

ROLL CHANGING APPARATUS 13 Claims, 22 Drawing Figs.

US. Cl 72/239, 72/245 Int. Cl B2lb 31/08, 8211) 31/32 Field of Search 72/237, 238, 239, 241, 243, 245;108/94, 103,139,141; 104/35, 36, 37, 47

[56] References Cited UNITED STATES PATENTS 1,031,055 7/1912 Edwards... 72/238 2,987,008 6/1961 Melmer..... 104/36 3,208,260 9/1965 Sieger et al. 72/239 3,394,576 7/1968 Shumaker 72/239 Primary Examiner-Charles W. Lanham Assistant Examiner-R. M. Rogers Attorney-Meyer, Tilberry and Body PATENTEnJun amen 35 3195 sum USUF 12 INVENTOR. WILLIAM C. SHERWOOD "iz yn, 74W #34;

A TTOF/VEVI PATENTED JUN 8 1971 SHEET 05 [1F INVENTOR. WILLIAM G. SHERWOOD PATENTEDJIJN 8:971 3,5831% sum UBUF 12 INVENTOR.

WILLIAM G. SHERWOOD PATENTEDJUN 8|97| sum D7UF 12 92 8 N 3 INVENTOR! 8 7 WILLIAM G. SHERWOOD A TTOF/Vf Y5.

Pmmw JUN 8197:

SHEET 08 0F 12 OmN m T N E V m LLIAM G. SHE RWOOD 777 if A 7 TUBA/Z PATEN-TEDJUN 8B7! SHEET 3583195 INVENTOR. WILLIAM G. SHERWOOD imy PATENTEDJUN am 3583.195

' sum -100F 12 PATENTEDJUN 8|97l $583,195

sum MM 12 F. Z BYWILLIAM c. SHERWOOD PATENTEDJUN 8I97| 3583.195

SHEET 120F 12 INVENTOR. WILLIAM G. SH ERWOOD ROLL CHANGING APPARATUS The present invention is directed toward the rolling mill art and, more particularly, to an improved apparatus for changing the rolls in a mill stand.

The invention is especially suited for use in changing both the backup rolls and the work-rolls in a four-high mill stand and will be described with particular reference thereto; however, it will be appreciated that the invention is capable of broader application and could be used for changing the rolls in a variety of types of mill stands for example, two and threehigh stands.

Apparatus for changing the work-rolls in a four-high mill stand is known which includes a horizontal, rotatably mounted platform. The platform is positioned adjacent to the mill stand with its axis of rotation offset from the plane containing the axes of rotation of the rolls. Additionally, the top surface of the platform is in generally the same plane as the lower surface of the lower work-roll.

To use the described apparatus for changing work-roll sets (i.e. a "set" including both an upper and a lower work-roll), a new or reconditioned roll set is positioned on the platform at one side out of alignment with the set in the mill stand. The used work-roll set is then moved from the stand onto the diagonally opposite side of the platform. Thereafter, the platform is rotated 180 to bring the new set into alignment with the stand to allow it to be pushed or pulled directly into position in the stand.

The above-discussed apparatus is advantageous in that it permits work-roll sets to be changed relatively quickly; however, it does present substantial problems when it is desired to change the backup rolls. Although backup rolls must be changed at relatively less frequent intervals than work-rolls, none-the-less, the loss in production time and the labor cost involved in changing the backup rolls can be considerable. The noted apparatus does nothing to facilitate backup roll changing and, in fact, can add to the time and problems involved. As can be appreciated, with the top surface of the platform in generally the same plane as the lower surface of the bottom work-roll, the body of the platform effectively prevents movement of the bottom work-roll out of the mill stand. For this reason, the apparatus must be substantially dismantled prior to backup roll removal. Additionally, with the apparatus removed it is still necessary to remove the backup rolls by the use of a C-hook or sled, procedures which can be both difficult and somewhat dangerous.

The present invention provides an improvement to the above-discussed apparatus which allows both work-rolls and backup rolls to be rapidly changed without the necessity of dismantling any structure; further, this is accomplished with a minimum of additional structure and only a nominal increase in first cost.

Specifically in accordance with the invention, the combination of a mill stand including a plurality of generally horizontal rolls and a rotatably mounted platform having a generally horizontal roll support surface is provided with the improvement which includes means for selectively producing relative vertical movement between the support surface and the rolls whereby the support surface can be brought into position for receiving all of the rolls in the stand.

In accordance with a more limited aspect of the invention, means are provided to shift the support surface of the platform between at least two predetermined elevations and power means are provided for rotating the platform about its axis of rotation in both of the two predetermined elevations.

Accordingly, aprimary object of the invention is the provision of a rotatable platform type roll changing apparatus which can be utilized for changing either the work-rolls or backup rolls ofa four-high mill stand.

Another object is the provision ofa mill and rotary-type roll changing apparatus which are arranged to permit relative vertical movement between the rolls in the stand and the roll support surface of the apparatus so that all of the rolls can be changed.

A still further object is the provision of apparatus of the type described wherein the roll inserting and removing apparatus can be used for charging both the backup rolls and the workrolls in a four-high mill.

Yet another object is the provision of a four-high mill stand with backup rolls which can be inserted as a set and, after insertion, be automatically separated to receive work-rolls therebetween as a set.

Still yet another object is the provision of a four-high mill stand and associated roll changing apparatus which permit sequential removal of work-rolls and backup rolls without modifying or disassembling the mill stand or roll changing apparatus.

Other objects are the provision of an apparatus of the type described which is relatively simple and reliable in operation and which greatly reduces mill down time during backup roll changing in a four-high mill.

These and other objects and advantages will become apparent from the following description when read in conjunction with the accompanying drawings wherein:

FIG. I is a side elevation of a four-high rolling mill stand provided with a roll changing apparatus formed in accordance with a preferred embodiment of the invention;

FIG. 2 is a plan view taken on line 2-2 of FIG. 1;

FIG. 3 is an enlarged side view of the mill stand shown in FIG. 1 showing the rolls in their working position;

FIG. 4 is a view similar to FIG. 3, but showing the rolls in a position wherein the work-rolls can be removed;

FIG. 5 is a view similar to FIGS. 3 and 4 but showing the mill stand when the work-rolls have been removed and the backup rolls are in position for removal;

FIG. 5a is a detailed sectional view taken on line 5a-5a of FIG. 5;

FIGS. 6 and 7 are plan views similar to FIG. 2 but showing the apparatus functioning to remove the work-rolls, and backup rolls, respectively;

FIG. 8 is a partial side elevational view similar to FIG. 1 but showing in somewhat more detail the connection arrangements for engaging the rolls and removing them;

FIG. 9 is a view taken on line 9-9 of FIG. 6 and showing the connection arrangement between the backup roll and the inserting and removal apparatus;

FIG. 10 is a view taken on line 10-10 of FIG. 7 showing in detail the connection arrangement between the work-rolls and the inserting and removal apparatus;

FIG. 11 is a cross-sectional view taken through the top of the mill stand and showing an upper roll balance mechanism which has been modified for raising the rolls during the roll changing operation;

FIG. 12 is an end view of that portion of the apparatus shown in FIG. 11;

FIG. 13 is a cross-sectional view through the bottom of the mill stand and showing the apparatus used for supporting the roll assemblies in a raised position during insertion and removal of the roll assemblies from the stand;

FIG. 14 is a cross-sectional view taken on line 14-14 of FIG. 13;

FIG. 15 is a cross-sectional view taken through the bottom of the mill stand on a vertical plane parallel with the roll axes to show the mechanism utilized to raise and lower the roll removing track sections used in the preferred embodiment of the present invention;

FIG. 16 is a view taken on line l616 ofFIG. 15;

FIG. 17 is an enlarged plan view of the roll removing and inserting platform;

FIG. 18 is a cross-sectional view taken on line 18-18 of FIG. 17 and showing the structural details of the roll removing platform;

FIG. 21 is an enlarged cross-sectional view taken on line 2I-2l of FIG. 19.

Referring now more particularly to the drawings wherein the showings are for the purpose of illustrating a preferred embodiment of the invention only and not the purpose of limiting same, FIGS. 1 and 2 show the overall arrangement of a roll receiving and handling assembly A associated with a mill stand B. Positioned on the side of the mill stand 8 opposite from the roll receiving and handling assembly A is an inserting and withdrawing apparatus C which functions to move the rolls and roll sets into and out of the mill stand.

The Roll Receiving And Handling Apparatus A As shown, the assembly A includes a rotatable platform 10 which is mounted adjacent the mill stand B for rotation about a vertically extending axis identified with the reference letter P. The axis of rotation of the platform 10 is offset from the vertical plane which contains the axes of the rolls of the mill stand B. This plane is noted by reference numeral 12 in FIG. 1.

Broadly, this general arrangement is well known in the art and has previously been used for facilitating changing of workroll sets. In the past however, the platform was positioned so that its top or roll receiving surface 14 was generally at the same level as the lower edge of the bottom work-roll of the work-roll set. In operation, a new work-roll set would be positioned on the platform at a location indicated by the dotted line showing 16 in FIG. 7. The used work-roll set would then be moved out of the mill stand into the dotted line position identified as 17 in FIG. 7. Thereafter the platform would be rotated to bring the new work-roll set 16 into alignment with the mill stand window. This new set could then be inserted into the mill stand and the used set taken from the platform for reconditioning.

This prior arrangement was generally satisfactory for removing work-rolls; however, as can be seen in FIG. I, with the top of the platform aligned with the bottom of the lower work-roll set, the lower backup roll is effectively blocked and can not be removed without disassembling at least a portion of the platform. Obviously, the platform could not be used for backup roll removal thus necessitating the use of overhead cranes and other similar apparatus. Alternately, an extremely complex multilevel removing apparatus was required.

The subject invention overcomes the prior problems and provides a roll removing and handling platform arrangement which can be used for removing both the work-roll set and the backup rolls. Although, as will become apparent as the description proceeds, a roll-receiving and handling platform A formed in accordance with the invention could have a variety of specific structural configurations, the preferred construction of the platform is as shown in FIGS. 17-20.

Referring particularly to the FIGS. 17 and 18, it is seen that the platform 10 includes a main top support member in the form of a generally circular plate 20. Plate 20 has a circumferentially positioned frame member 22 extending downwardly from its lower surface and terminating in a transversely extending circumferential flange 24. As will subsequently be described, flange 24 serves as a drive member for the platform rotating drive unit.

The platform 20 is supported from an intermediate frame assembly 30 which, as best shown in FIGS. 18 and 19, includes four beams 31 through 34 connected to form a generally square frame. A similar beam member 35 is connected diagonally between the side members 32 and 34 and a short beam member 36 extends between the side frame member 33 and the diagonal member 35. Similarly, two

other beam members

37 and 38 are connected between the side member 31 and the diagonal member 35. Diagonally positioned in each comer of the main frame are four members 39.

The platform 10 is rotatably supported on the intermediate frame 30 by roller members 40 which are carried on the intermediate frame at the locations shown in FIG. 19. These roller members are arranged to engage the transversely extending flange 24 on the platform 10. The platform is also provided with a sleeve 44 which extends vertically downwardly from the center of plate 20 and receives a upwardly extending spindle 42 connected to frame member 35. Consequently, as can be seen, the platform 20 is freely rotatable relative to the intermediate frame 30.

The platform is enclosed by a rectangular housing defined by four vertically extending plates 50-53 which are respectively connected to the top surfaces of the frame members 3l-34. Additionally, similar plates 54 are positioned angularly in each corner between the sideplates, and a top cover 56 is joined to the upper edges of the sideplates 50-53 at an elevation corresponding to the elevation of the circular plate 20.

Power means are provided for selectively rotating the support platform l0 relative to the intermediate frame 30. These means could take a variety of forms; however, as best shown in FIGS. l8, l9, and 21, the preferred drive arrangement comprises a friction drive unit 60 which includes a main, relatively large diameter friction wheel 62 having its outer surface 64 covered with rubber or similar material. Wheel 62 is keyed to shaft 66 which is rotatably mounted in

suitable bearings

68 and 70. As shown in FIGS. 19, and 21, the bearings are supported by

members

72 and 74 which extend between the

members

37 and 38 of the intermediate frame 30. The wheel is located so as to be in vertical alignment with the lower surface of the platform flange 24.

Referring to FIG. 21 it is seen that the bearing 68 is carried by a U-shapcd member 76 which is seated over the support member 72 and carried on spacer washer 77. The member 76 is merely seated on member 72 so as to be capable of slight pivotal movement about member 72. It is prevented from moving longitudinally on member 72 by a pair of vertically extending stop members 79 (See FIG. 19).

The bearing 70 is similarly mounted on a U-shaped support or mounting member 78 which is carried from the support member 74 by Belleville springs 80. These springs function to maintain a desired preload between the friction wheel and the flange and, additionally, when the platform deflects slightly under load, the springs permit a slight deflection of the friction wheel 64. Consequently, the proper drive engagement is maintained between the friction wheel 62 and the flange 24 at all times.

The drive or friction wheel 62 could be driven in many different ways; however, in the embodiment under consideration, a conventional reversible electric motor 86 provided with a brake unit 88 is used. As shown, the'motor and

brake

86, 88, are supported from a platform carried by the intermediate frame 30. The output shaft of the motor 86 is connected with a right-angle gear unit 84 carried by

intermediate frame members

37 and 38. The right-angle drive unit 84 is drivingly connected with the wheel 62 by couplings 82 and shaft 83. As can be appreciated, this drive assembly permits the platform 10 to be rotated in either direction about its vertical axis and stop at substantially any desired location.

In order to permit the platform to be locked in desired positions of rotation during roll changing, a lock unit 90 is provided. Referring to FIGS. 18 and 19, it is seen that the lock unit 90 includes a vertically reciprocable lock pin 92 having a tapered upper end. The lock pin 92 is carried in a sleeve or guide member 93 for reciprocation by a fluid cylinder 94. The guide sleeve 93 and the fluid cylinder 94 are both connected to and carried by a support plate 96 mounted to the intermediate frame member 36. Tapered pin receiving openings are provided on the underside of platform 10 for locking engagement by the upper end of the pin 92. Referring to FIG. 18, it is seen that a pin receiving member 98 is positively connected to the underside of the platform. Any number of such receiving members can be provided at desired locations under the platform. Consequently, after the platform has been rotated to the desired location, actuation of the cylinder 94 will cause engagement of the lock pin 92 to thus lock the platform 10 against rotation.

For reasons which will hereafter become apparent, the entire intermediate frame 30 and the platform are supported from a main base frame assembly indicated generally with the reference number 100. Referring to FIGS. 18 and 20, it is seen that the main base frame is formed primarily by four large beams 101 through 104 which are positioned about an access or inspection pit 106.

As previously mentioned, according to the invention, the platform 10 is arranged to be raised and lowered so that both work-rolls and backup rolls can be changed. Although many different arrangements could be provided, according to the subject embodiment, this is accomplished by supporting the intermediate platform 30 from the main base frame 100 by four scrcwjuck units 108. As noted in FIGS. 19 and 20, the screwjuck units 108 are positioned so as to engage the under surfaces

ofintermediatc frame members

31 and 33 at location 109. The jacks 108 are simultaneously driven by a reversible electric motor and brake unit 110 which is connected with the scrcwjacks 108 by right-angle drives 113 and 114 and drive shafts 116 interconnected by conventional couplings. Con sequently, the platform 10 can be moved to any desired vertical position; and, because the rotating drive unit also moves with it, it can be rotated at any vertical position.

To assure proper guiding of the intermediate frame 30 during its vertical movement, four vertically extending guide posts 120 are supported from the base frame 100 by pedestals 122 (See H6. As shown in FlG. 19, the guide posts 120 extend upwardly through guide sleeves 124 carried by plates 126 positioned in the corners of the intermediate frame as shown in FIG. 19. As is apparent, this arrangement prevents lateral shifting of the intermediate frame or platform during its vertical movement.

Although not of importance to the present invention, support posts 128 (See FIGS. 18 and 20) are provided to support the platform 10 when it is in its lower position as shown in FIG. 18. These support posts 128 extend vertically upward from the access or pit 106 and are positioned to engage the under surface of the platform 10. Accordingly, the screwjacks must carry only the weight of the intermediate frame when the platform is in its lower position. This avoids possible damage to the support rollers 40 or the screwjacks 108 when the roll assemblies are being transferred to and from the platform by an overhead crane.

As can be appreciated, roll changing support platforms formed according to the invention can be readily utilized for changing both the work-rolls and the backup rolls in a fourhigh mill. Merely by providing the platforms with sufficient vertical movement to allow them to shift to the height corresponding to all of the rolls, the rolls can be simply moved from the mill directly into the platform. However, because of the substantial height of some mill stands, a platform capable of moving to all the desired levels would require an extremely large elevating mechanism. For this reason, according to a further aspect of the invention, it is preferable to use the roll removing platform in combination with a specially designed mill stand which is provided with means to allow the rolls and rolls sets to be shifted to different horizontal elevations within the stand. For reasons which will hereafter become apparent, this combination provides substantial advantages.

Mill Stand B Broadly, the construction and operation of mill stand B can best be understood by reference to FIGS. 1 through 4. in general, the mill stand 13 includes a basically conventional frame 150 which includes a pair of side frames 152 and 154 having the usual access openings or windows." The side frames 152, 156 are joined at their upper end by a crown member 156. Conventional screwdown screws and drive

mechanisms

158 and 160 are provided to provide the necessary rolling forces.

The embodiment shown is a four-high mill and includes a pair of relatively small diameter work-

rolls

162a and 162b.

The work-rolls are each associated with a corresponding backup roll 164a and l64b. The work-rolls are driven in a conventional manner by releasable spindles 166 which extend from a main gear housing 168 driven by a prime mover not shown. Additionally, a conventional spindle support assembly 169 is provided to maintain the spindles in position when the work-rolls are removed.

Referring to FIGS. 3 and 4, it is seen that the upper backup roll 164a is carried in chocks 170. Although only the left-hand chock (as viewed in FlG. 1) is shown, it is to be understood that the right-hand chock is of basically the same construction. lt will be noted that the chock 170 is mounted for vertical sliding movement in the side frame window and retained therein in a conventional manner by keeper plates 172 which engage vertically extending grooves formed in the chock. The keeper plates 172 are, of course, arranged so that they can be moved laterally to permit the backup roll and its chucks to be moved transversely through the mill window. In the embodiment shown, the keeper plates 172 are provided with elongated mounting openings which receive releasable stud bolts 173.

The lower backup roll l64b is similarly provided with chocks 174 which are engaged by keeper plates 176. Keeper plates 176 are received in vertical grooves formed in the lower backup roll chocks 174. A recess 177 is formed centrally of each keeper plate for passage of wheel assemblies 252 when the lower backup roll is in the position shown in FIG. 5. Additionally, as best shown in H6. 5a, the plates are tapered at surfaces 179 to guide the backup roll chock into its proper transverse position when it is lowered from the position shown in FlG. 5 to the position shown in FIG. 3.

The work-rolls 162a and l62b are provided with chocks 180 and 182 which are related so that the work-rolls can be removed from the mill stand as a set or a unit. In particular, it is seen that the lower work-roll chocks 182 are engaged by transversely driven keeper plates 184 which can be selectively actuated by fluid cylinders 186. As best shown in H0. 3, the upper work-roll chock is carried by the lower work-roll chock between a pair of upwardly extending legs 188 formed on the lower work-roll chock. Keeper plates 190 extend from legs 188 into engagement with vertical grooves formed in upper work roll chock 180. Conventional sets of

counterbalance cylinders

191, 192, and 193 are built into the various roll chocks.

As can be appreciated, FIG. 3 shows the rolls in their normal working position. To permit the work-rolls to be removed from the mill stand it is, of course, necessary that the backup rolls be separated or removed from engagement with the work-rolls. In the subject embodiment, this is accomplished by a novel roll lifting and elevating assembly. Referring specifically to FlGS. 4, 11, and 12, it is seen that carried within the mill frame crown 150 is a lift assembly 200 adapted to lift the upper backup roll and its chocks away from the upper workroll. Although the lift assembly 200 could be a variety of different arrangements, in the preferred embodiment it includes a large diameter hydraulic cylinder 202 supported from a frame 204 carried in the crown 150. The hydraulic cylinder 202 is positioned with its piston rod 206 extending vertically upwardly. The upper end of the piston rod 206 is connected by a pin 207 to a pair of plate members 208 which are connected by transversely extending plates 209. Pinned to the outer end of the plates 208 and extending downwardly therefrom are a pair of support or hanger rods 210. The lower ends of hanger rods 210 are each pinned to a pair of support plates 212 which extend between members 214. As best shown in FIG. 12, the outer ends of the members 214 are each welded or otherwise positively connected to chock hanger members 216. Referring to F103. 4 and 11 it is seen that the chock hanger members 216 extend in parallel relationship through the top of the mill between the windows of side frames 152 and 154. Each of the hanger members 216 includes an inwardly extending lip or flange portion 128. Support plates or bearing surface members 219 are carried generally at the opposite ends of each of the members 216.

Referring to FIG. 12 is is seen that the upper backup roll chock includes outwardly extending flange or lip portions 220 which extend outwardly over the bearing surfaces 219 carried on the flanges 218. Consequently, by controlling the actuation of the lift cylinder 202 the upper backup roll 164a can be lowered into position on the upper work-roll as shown in FIG, 3. Alternately it can be lifted away from the work-rolls to the position shown in FIG. 4 so as to free the work-rolls.

As can be appreciated, in order to permit the work-rolls to be easily moved out of the mill stand, not only must the upper backup roll be lifted away from the work-rolls, but also, means must be provided to permit free movement of the work-rolls relative to the lower backup roll. For this reason, each ofthe lower work-roll chocks 182 are provided with a pair of rollers 222 mounted for rotation about a horizontally extending axis. A second pair of rollers 224 are also carried on the lower work-roll chock and positioned with their axis of rotation extending vertically. The

rollers

222 and 224 are arranged to engage elongated truck forming members 226 carried in the lower backup roll chocks I74. Referring to H65. 1 and 3, it is seen that the track forming members 226 are carried in grooves or slots formed in the top of each of the lower backup roll chocks and extend transversely through the mill. To lift the work-rolls away from the lower backup roll, the trackforming members 226 are arranged to be actuated between a lowered position shown in FIG. 3 and a raised position shown in FIG. 4. This could be accomplished with different arrangements; however, the subject utilizes hydraulic cylinders 228 carried in each of the backup roll chocks 174.

Referring more particularly to FIGS. 2 and 17, it is seen that the track sections 226 are positioned so that their outer ends meet with corresponding track members and wear plates 230 carried on the top of the platform 10. Platform is alsoprovided with parallel grooves or slots 232 arranged to receive the guide rollers 224 which extend downwardly from the lower surface of the lower work-roll chock 182. Accordingly, when the platform 10 has been moved to an elevation corresponding to the elevation of the track member 226 the work-rolls can be moved or rolled directly from the mill stand onto the platform. Thereafter, the platform can be rotated 180 to bring the new or reconditioned work-roll set which has previously been positioned on the other pair oftrack members 230 into alignment with the mill stand. This new work-roll set can then be moved into the mill.

As previously discussed, it would be possible to arrange the platform 14 so that it could have an amount of vertical adjustability sufficient to allow it to be moved to elevations that would permit it to receive the backup rolls from their normal working positions. In accordance with a further aspect of the subject invention however, the lower backup roll is arranged to be shifted a substantial distance vertically while it is in the mill stand. This allows a smaller amount of vertical adjustability of the roll receiving platform to satisfy the need for backup roll removal. Moreover, the resulting combination is more advantageous for several other reasons.

Referring to FIGS. 4, l5 and 16 the structural details of the preferred embodiment of the backup roll elevating assembly 250 will be described. As shown, in FIGS. 4 and the lower backup roll chock is provided with small wheeled carriages 252 each of which include support rollers 254 and guide rollers 256. The rollers are positioned to engage an elevating track section or platform 258 mounted transversely in the base of the mill stand. As shown, platform 258 has transversely extending tracks 260 carried thereon. The elevation track section 258 is arranged to be actuated upwardly by a large diameter hydraulic cylinder 262 carried in the base of the mill stand. As best shown in FIG. 15, the piston rod 264 of the cylinder 262 is positioned to engage the center of the elevating track section 258.

To assure that the track section 258 moves upwardly without lateral shifting or tilting, an equalizing unit is provided. This unit includes a pair of guide rods 266 which extend downwardly from the bottom of track section 258. The guide rods 266 pass through guide sleeves or openings in the base of the mill stand. Additionally, the guide rods are mechanically inner connected so as to require that they both move simultaneously. In particular, it will be noted that the lower end portion of each of the guide rods 266 has a track gear section 268 formed thereon. A pair of pinion gears 270 engage the gear section 268 of each of the guide rods 266. The pinion gears 270 are keyed or otherwise positively connected to a horizontally extending shaft 272 which is rotatably carried by a bracket 274 extending downwardly from the base of the mill stand. Accordingly, when the hydraulic cylinder 262 is actuated to move the elevating platform 258 upwardly, the guide rods 266 are both constrained to move upwardly an equal amount, thereby assuring precise guided movement of the platform.

Although, it would of course be possible to support the platform 258 in various selected elevational positions through the use of the hydraulic cylinder 262, it is preferable that there be a positive mechanical support. For this reason, support units 290 are provided at each end of the track 260. The support units 290 are identical in construction and accordingly, only one will be described in detail. Referring to FIGS. 13 and 14, it is seen that each of the support units 290 includes a pair of

oscillatible arms

292 and 294 which are pivotally connected through

respective pins

296 and 298 to a base frame member 300. Referring to FlG. 13 it will be noted that each of the

arms

292 and 294 include two spaced support surfaces 301 and 301', 302 and 302'. When the arms are in the solid line position shown in H0. 13 the tracks 260 are in their lower most position. When the tracks are moved upwardly to the elevation indicated by small letter a, the arms can be oscillated to the dotted line position identified with the

reference numerals

304 and 304. ln this position the support surfaces 301 and 301'; are under the track sections 260 as shown by dotted lines. Consequently, the track sections are given a positive mechanical support.

When the tracks 260 have been moved to the elevation indicated by small letter b, the arms are actuated to the dotted line position identified by reference numerals 306 and 306'. In this position the support surfaces 302 and 302' are directly under the tracks and serve to provide the desired mechanical support.

The means for oscillating the arms could take a variety of forms; however, the preferred embodiment the means utilized preferably comprised a fluid cylinder 310 which is pivotally supported from a frame 312 which depends from the support frame 300. The piston rod 314 of the cylinder 310 extends into pivotal engagement with a pair of lever arms 316 which are connected to the arms 392. Additionally, the

arms

292 and 294 are drivingly connected by

mating gear segments

318 and 320 attached to their inner or lower most ends. This arrangement, of course, assures, that movement of arm 302 under the influence of cylinder 310 produces a corresponding movement of arm 294.

Roll Inserting and Removing Apparatus C Although many different types of devices could be provided for moving the rolls into and out of the mill stand, the preferred arrangement is as best shown in F165. 6-10. Referring particularly to FIG. 6 it will be seen that the roll removing and inserting apparatus C includes a pair of long stroke

hydraulic cylinders

350 and 352. The

cylinders

350 and 352 are positioned in generally parallel relationship and have their

respective piston rods

354 and 356 extending toward the mill stand. Mounted at the ends of the piston rods are connectors or

roll engaging elements

352 and 360. Referring to FIG. 8 it is noted that the two

cylinders

350 and 352 are at slightly different elevations.

The manner in which the connecting

members

358 and 360 engage the work-rolls can best be understood by reference to FIGS. 7 and 10. Note that the connecting member 360 extends outwardly a distance greater than the connecting member 358. The member 360 terminates in a pusher unit 362 arranged to engage a short outwardly extending portion 364 connected to a chock of the lower work-roll. The connccting member 358 however, is relatively shorter and has an overhanging anddownwardly extending lip 364 carried on its outer end. A outwardly extending arm or connector 366 is welded or otherwise positively connected to the chock of the lower work-roll. This arm has an upwardly extending lip 368 at its outer end. FIG. l8 shows the normal relationship between the connector 358 and the arm 366. When the workroll assembly is to be removed from the mill however, it is moved upwardly a short distance by actuation of the elevating cylinder 262 and the track elevating cylinders 228 (See FIGS. 4 and 15). The upward movement of the work-rolls causes the lip portion 368 of arm 366 to move under the downwardly extending lip portion 364 of the connector 358. Additionally, the member 364 comes into alignment with pusher 362 (See FIG. 7). Thereafter, actuation of the

cylinders

350 and 352 will cause the work-roll set to be pushed out of the mill. Because of the relative length differences between the

connectors

358 and 360, the platform can be rotated without disconnecting or moving the

cylinders

350 and 352. Additionally, the new work-roll assembly which has similar arm and pusher portions will rotate directly into engagement with the

connectors

358 and 360. During the period that the used work-roll is being rotated away from the connecting elements the

piston rods

354 and 356 would normally be relatively unsupported. For this reason, a leg portion 370 depends from each connector is provided to engage the track and support the free end of the piston rod.

The

connector elements

358 and 360 are also arranged to be selectively connected to the lower backup roll chock. Referring to FIGS. 6, 9 and 10 it is seen that pins 372 and 374 extend transversely through openings formed in each of the connecting

units

358 and 360. These pins are arranged so they can be manually moved into and out of the openings. Vertical lock pins 376 are manually insertable to lock the

pins

372 and 374 in position. In FIG. 8, the lower backup roll assembly is shown as being provided with

arms

380 and 382 which terminate in end portions having pin-receiving grooves. As the lower backup roll is moved vertically, these grooves receive the transversely extending

pins

372 and 374. It is important to not in FIG. 6 that the arm portions engage the connector 360 are double and which receive the outer most end of the connector (which end is the pusher for the work-roll assembly). After the backup rolls have been moved to the platform the

pins

372 and 374 are manually removed so that an overhead crane may take the backup roll set from the platform. The new backup roll set can thereafter be lowered into position directly over the arms and the pins reinserted.

Typical Cycle of Roll Changing Operation As previously mentioned, the subject apparatus can be utilized for changing only the work-rolls or, changing both the backup rolls and the work-rolls. The most often used procedure is, of course, changing the work-rolls. A preferred procedure for changing work-rolls will be described; however, it should be understood that the described procedure is merely one way in which the equipment can be utilized to change work-rolls.

When it is desired to change work-rolls, the platform 10 is rotated to bring one of its sets of tracks into alignment with the mill stand. The platform locking pin 92 (Sec FIG. 18) is preferrably extended to lock the platform in position. The counterbalance and contour cylinders between the work-rolls and the backup rolls are shut off. The screwdown screws are actuated to their uppermost position and the upper backup roll is elevated by actuating the lift cylinder 202 (See FIG. 11). Thereafter, the tracks 226 in the lower work-roll chocks are actuated upwardly and lift the work-roll set away from the lower backup roll. Subsequently, the elevating mechanism 250 is actuated to raise the lower backup roll a distance indicated by the reference letter a in FIG. 13. The lower backup 10 roll is then locked in this position by actuation of the support assembly 290.

Of course, during the movement of the lower backup roll to the elevation a, the connector arms 364 and 366 (See FIGS. 7 and 8) move into engagement with the latching

member

360 and 358. Thereafter, the

cylinders

350 and 352 are actuated to push the used roll assembly out of the mill and on to the platform.

Normally, a new work-roll set will have been previously positioned on the platform. Consequently, the platform is then rotated and the new work-roll set brought into alignment with the mill stand. The rotation of the platform causes the engaging arms on the chocks of the new work-roll set to enter the connectors on the inserting removing apparatus C. Thereafter the

cylinders

350 and 352 are actuated to move the new set to the mill. The above-described sequence of operations regarding the lifting and separating of the rolls is then carried out in reverse order and the work-rolls brought to their final working position.

If it is desired to change the backup rolls, the same basic sequence of operations required for changing the work-roll set is carried out; however, after the used work-roll set has been moved to the platform, the platform is lowered and the

cylinders

350 and 352 retracted. The used work-roll set is thereafter taken away by an overhead crane leaving the platform in front of mill window free and clear. Subsequently, the elevating assembly 250 shown in FIG. 15 is actuated to move the lower backup roll set to a position indicated by reference line b in FIG. 13. The support assembly 290 is then actuated to its upper most support position to support the lower backup roll.

With the lower backup roll assembly in the raised position the lifting mechanism 200 (Shown in FIG. 11) is operated to lower the upper backup roll into position on the lower backup roll (See FIG. 5).

Note that the upper backup roll chocks have small extended legs 380 which engage the lower backup roll chock to assure alignment and support the upper backup roll spaced above the lower. The upward movement of the lower backup roll has, of course, brought the

connectors

360 and 358 into engagement with the connector pins 372 and 374 (See FIG. 6) the

cylinders

350 and 352 are then actuated to push the backup roll set from the mill. Once the set is on the platform it is preferably immediately taken away by an overhead crane and a second backup roll set lowered into position over the connecto. members. This set is then pulled back into the mill and the upper backup roll lifted into position by the elevating assembly and the lower backup roll moved down to elevation at of FIG. 13.

Thereafter

cylinders

350 and 352 are actuated back through the mill into position for receiving a work-roll set. Preferably, a new work-roll set has been or was brought into position during the time of the backup rolls were changed. Platform 10 can then be rotated to swing this new set into engaged relationship to the inserting and removing apparatus. After being pulled into the mill the new workroll set is taken to its working position in the manner previously described. I

The subject invention has been described in great detail sufficient to enable one of ordinary skill in the rolling mill art to make and use the same. Obviously, modifications and alterations of the preferred embodiment and its use will occur to others upon understanding of this specification and it is my intention to include all such modifications and alterations as part of my invention in so far as they come within the scope of the appended claims.

lclaim:

1. Apparatus for changing the rolls in a mill stand comprising: a horizontally positioned, generally circular platform provided with a pair of generally parallel roll-receiving guideway forming means positioned substantially equal distances from the vertical centerline of said platform for receiving rolls moved onto said platform from said mill stand; a support frame means subjacent said platform and supporting said platform for free rotation about its vertical centeriine; power means for selectively moving said platform relative to said support frame means between at least two vertically spaced e evations so that said platform can be horizontally aligned wath at least one of said rolls; lock means for selectively locking said platform in at least one predetermined position of rotation; and, drive means movable vertically with said platform for rotating said platform through a circumferential extent of at least l80 at either of said two vertically spaced positions.

2. The apparatus as defined in claim 1 including an intermediate frame means positioned between said platform and said support frame, said intermediate frame rotatably supporting said piatform and movable vertically therewith relative to said support frame; and, means for preventing relative rotation between said support frame and said intermediate frame.

3. The apparatus as defined in claim 2 wherein said drive means is carried by said intermediate frame.

4. The apparatus as defined in claim 2 wherein said lock means is actuable to prevent rotation between said platform and said intermediate frame.

5. The apparatus as defined in claim 2 wherein said power means include jacks positioned between said support frame and said intermediate frame.

6. In the combination ofa mill stand including a plurality of generally horizontal rolls arranged in vertical alignment and a rotatably mounted platform having a generally horizontal roll support surface positioned adjacent the mill stand with its axis of rotation extending vertically and offset from the plane containing the axes of the rolls, the improvement comprising: power means for selectively producing relative vertical movement between the support surface and the rolls whereby the support surface and at least two of the rolls can be brought in to horizontal alignment; said power means including first means for selectively moving said support surface between at least two vertically spaced elevations and second means for moving said rolls vertically in said stand.

7. The improvement as defined in claim 6 wherein said mill stand is a four-high mill having a pair of work rolls with backup rolls associated therewith, and wherein said power means includes first means for lift ng the upper backup roll independently of said lower backup roll.

8. The improvement of claim 6 wherein said power means further includes a second means for lifting the lower backup roll to at least two different vertical positions.

9. The improvement as defined in claim 6 wherein said support surface is mounted for vertical movement between at least two positions and rotating means are provided for rotating said surface at either of said two positions.

.10. The improvement as defined in claim 9 including means for locking said surface in selected positions of rotation.

11. The improvement as defined in claim 9 wherein said rotating means moves with said platform.

12. Apparatus for changing the rolls in a mill stand comprising: a horizontally positioned, generally circular platform provided with a pair of generally parallel roll receiving guideway forming means positioned substantially equal distances from its vertical centerline; a support frame means subjacent said platform and supporting said. platform for free rotation about its vertical centerline; power means for selectively moving said platform relative to said support frame means between at least two vertically spaced elevations; lock means for selectively locking said platform in at least one predetermined position of rotation; and, drive means movable vertically with said platform for rotating said platform through a circumferential extent of at least l at either of said two vertically spaced positions, said drive means including a motor carried by an intermediate frame positioned between said platform and said support frame means.

13, The apparatus as defined in claim 12 wherein said intermediate frame is supported from said support frame by a plurality ofjack means.

Claims

1. Apparatus for changing the rolls in a mill stand comprising: a horizontally positioned, generally circular platform provided with a pair of generally parallel roll-receiving guideway forming means positioned substantially equal distances from the vertical centerline of said platform for receiving rolls moved onto said platform from said mill stand; a support frame means subjacent said platform and supporting said platform for free rotation about its vertical centerline; power means for selectively moving said platform relative to said support frame means between at least two vertically spaced elevations so that said platform can be horizontally aligned with at least one of said rolls; lock means for selectively locking said platform in at least one predetermined position of rotation; and, drive means movable vertically with said platform for rotating said platform through a circumferential extent of at least 180* at either of said two vertically spaced positions.

2. The apparatus as defined in claim 1 including an intermediate frame means positioned between said platform and said support frame, said intermediate frame rotatably supporting said platform and movable vertically therewith relative to said support frame; and, means for preventing relative rotation between said support frame and said intermediate frame.

6. In the combination of a mill stand including a plurality of generally horizontal rolls arranged in vertical alignment and a rotatably mounted platform having a generally horizontal roll support surface poSitioned adjacent the mill stand with its axis of rotation extending vertically and offset from the plane containing the axes of the rolls, the improvement comprising: power means for selectively producing relative vertical movement between the support surface and the rolls whereby the support surface and at least two of the rolls can be brought in to horizontal alignment; said power means including first means for selectively moving said support surface between at least two vertically spaced elevations and second means for moving said rolls vertically in said stand.

7. The improvement as defined in claim 6 wherein said mill stand is a four-high mill having a pair of work rolls with backup rolls associated therewith, and wherein said power means includes first means for lifting the upper backup roll independently of said lower backup roll.

10. The improvement as defined in claim 9 including means for locking said surface in selected positions of rotation.

12. Apparatus for changing the rolls in a mill stand comprising: a horizontally positioned, generally circular platform provided with a pair of generally parallel roll receiving guideway forming means positioned substantially equal distances from its vertical centerline; a support frame means subjacent said platform and supporting said platform for free rotation about its vertical centerline; power means for selectively moving said platform relative to said support frame means between at least two vertically spaced elevations; lock means for selectively locking said platform in at least one predetermined position of rotation; and, drive means movable vertically with said platform for rotating said platform through a circumferential extent of at least 180* at either of said two vertically spaced positions, said drive means including a motor carried by an intermediate frame positioned between said platform and said support frame means. 13, The apparatus as defined in claim 12 wherein said intermediate frame is supported from said support frame by a plurality of jack means.