Mill roll changing system including a cantilevered roll assembly
United States Patent 1 Petros Apr. 15, 1975 [75] Inventor: Andrew J. Petros, Oakdale, Pa.  
 [73] Assignee: Mesta Machine Company,  
 Pittsburgh, Pa.  
 [22] Filed: Dec. 28, 1973 [21] Appl. No.: 429,344  
 Moffett 72/238 Shumaker 72/239 Primary Examiner-Milton S. Mehr Attorney, Agent, or Firm-Donn J. Smith 571 ABSTRACT The cantilevered roll assembly comprises a first mill.  
 roll, a first bearing chock rotatably mounted adjacent one end of the first roll, a second mill roll disposed generally above the first mill roll, and a second bearing chock rotatably mounted adjacent one end of the second mill &#39;roll and disposed generally above the first bearing chock. Means are provided for detachably joining the second bearing chock to the first bearing chock such that the second mill roll and the second bearing chock are supported from the first bearing chock in cantilevered fashion whereby the roll assembly can be inserted and withdrawn relative to a stand of the mill without removing strip or the like therefrom.  
 22 Claims, 4 Drawing Figures PATENTEDAPR 1 5:915  
 sum 1 pg 2 Certain aspects of the present invention are related to the invention of my copending, ctrassigned application entitled Mill Roll Changing System Including a Roll Buggy filed concurrently herewith, Ser. No. 429,345  
  The present invention relates to a system for inserting and withdrawing the rolls of a rolling mill and more particularly to a novel form of cantilevered work roll assembly which can be so inserted and withdrawn without removal of the strip or the like from the rolling mill.  
  Although the invention is described&#39;in conjunction with a four-high mill stand of a cold mill, it will be apparent as this description proceeds that the invention can be readily designed for a hot mill and for other types of rolling mills. Thus, each configuration of the roll assembly of the invention involves specific but obvious differences in size and configuration, depending upon a particular form and function of a rolling mill stand. The invention is particularly advantageous in its adaptability to existing rolling mills, as the mill roll assembly of the invention can be substituted readily for conventional roll assemblies.  
  Known forms of roll changing systems suffer from one or more disadvantages and difficulties in operation. The original or manual system involves considerable mill down time, attendant loss of production, and personnel hazard. Changing the rolls of more than one or two mill stands at a time has been virtually impossible owing to equipment and personnel limitations. Many of these known systems require extensive modification of individual rolling mill stands and related equipment, and as a practical matter installation was effectively limited to newly constructed rolling mills.  
  In other roll changingsystems, owing to mechanical complexity and plant area requirements, only one or a limited number of mill stands could be serviced at a time. Prior roll changing systems usually necessitated many structural changes in the floor area surrounding the mill stands and in the mill stands themselves with attendant time-consuming operations and personnel hazards.  
  The roll-changing system of the present invention is admirably and unexpectedly designed to reduce undue mechanical complexity and to facilitate maintenance. The system of the present invention can be installed in conjunction with existing rolling mills without extensive and costly mill shutdown. Roll changing equipment according to the invention can be installed wherever and whenever desirable, at each stand of a given rolling mill, with the result that any or all of the work roll assemblies of the mill can be changed simultaneously. Handling of the work rolls by a crane is eliminated, along with roll damage frequently caused by this and other known handling techniques. Most importantly, a normal roll changing system and roll assembly permit withdrawal and insertion of the roll assembly without the necessity of time-consuming removal and rethreading of the strip or the like from the rolling mill. In most applications, my novel mill roll assembly facilitates transportation of the roll assemblies to and from the roll shop.  
  In the usual type of rolling mill. the reduction of down time resulting from eliminating removal and rethreading of the strip or sheet is obvious. The use of my novel work roll assembly, which can be cantilevered during insertion and removal thereof, permits removal of the assembly without disturbing the strip which remains within the mill stand where it can be suspended at or near the pass line by the conventional strip guides of the stand.  
  In the usual type of cold strip mill, a series of individual coils of strip are normally fed into the mill, with roll changes being made between the coils. As such roll changes can be quite frequent, the number of coils that can be joined end to end to avoid rethreading of the mill is limited, and rethreading of the mill has heretofore been required after each roll change. However, it would be advantageous from many view-points to combine the rolling operation with pre-reduction and/or post-reduction processes, such as pickling, annealing and coating operations. For the postulated combined operation, it would be necessary for the strip to be processed in a continuous ribbon uninterrupted by frequent roll-changing operations. It is imperative, there fore, for the work rolls in such combined operation to be changed with the strip remaining within the individual stands of the mill. The novel roll assembly of the present invention makes this type of combined operation feasible.  
  I accomplish these and other desirable ends of the invention and overcome the disadvantages of the prior art by providing a mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, and means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill without removing strip or the like therefrom.  
  I also desirably provide a similar roll assembly including quick-deactivatable spacing means coupled between said bearing chocks for spacing said chocks and rolls during said insertion and said withdrawal, and means for deactivating said spacing means to permit contact between said rolls and said strip when said roll assembly is positioned within said stand.  
  I also desirably provide a similar roll assembly including mill clamp means on said mill stand, said clamp means having a deflecting member for engaging and deactivating said spacing means upon closure of said mill clamp means upon said bearing chocks.  
  I also desirably provide a similar roll assembly wherein said spacing means include a pair of spacing dogs pivoted to one of said bearing chocks and pivotable to positions of bearing and separating engagement with the other of said bearing chocks, and means for biasing said pivoted dogs towards the bearing engagement positions respectively.  
  I also desirably provide a similar roll assembly including an additional bearing chock rotatably mounted on each of said first and said second rolls adjacent the other ends thereof respectively, and restraining means extending between each of said first and said second bearing chocks and the associated additional bearing chock for maintaining a predetermined rotative attitude of each of said additional bearing chocks.  
  I am aware of other cantilevered roll assemblies, as exemplified by the US. Pats. to:  
 Hermann Leitner, No. 3,718,020  
  Jan. .I. Gawlikowicz et al., No. 3,718,026 I am also aware of the split chock arrangement of Adair U.S. Pat. No. 3,754,426, which chock arrangement is not supported in cantilevered fashion. In general, these Patents do not disclose the novel features of my invention pointed out above and described in detail below.  
  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 an end elevational view of a cantilevered roll assembly arranged in accordance with the invention. FIG. 1 represents in solid outline one disposition of the roll assembly during the roll changing operation, and in partial chain outline the operating position of the roll assembly within a typical mill stand.  
  FIG. 1A is a partial sectional view of the mill roll assembly shown in FIG. 1 and taken along reference line IAIA thereof;  
  FIG. 2 is a side elevational view of the mill roll assembly shown in FIG. 1; and  
  FIG. 3 is a top plan view of the mill roll assembly as shown in FIG. 2.  
  With reference now to the drawings in greater detail, a work roll assembly according to the invention comprises upper work roll 22 and lower work roll 24. The upper work roll is provided with work side and drive side bearing chocks 26, 28 respectively and rotatably mounted on the roll necks. The lower roll 24 is similarly provided with chocks 30, 32 each of which is provided with a pair of railway trucks 34, 36 for engagement with rails 38, 40 of a typical mill stand 42. The rails 38, 40 are aligned with external rails (not shown) disposed adjacent the mill stand 22 for roll changing purposes. The aforementioned external rails can be arranged into a variety of configuration, e.g., as set forth in the aforementioned copending application Ser. No. 429,345, in my copending, coassigned application entitled SlDE-SHIFTING MILL ROLL CHANG- ING SYSTEM Ser. No. 371,766, filed June 20, 1973, or in coassigned U.S. Pat. Nos. 3,691,809 and 3,733,876 of Joseph L. I-Ilafcsak. The work side chock of the lower work roll 24 is further provided with a hook 44 co-operative with suitable traction means (not shown) for inserting and withdrawing the work roll assembly 20 along the rails 38, 40 and the aforementioned external roll changing rail means.  
  The drive side bearing chocks 28, 32 of the roll assembly 20 are essentially conventional in construction and will not be described further save in conjunction with the elongated restraining member or rod 46 and lubricant tube 48 (FIGS. 2 and 3) detailed below. Moreover, owing to the cantilevered support of the work rolls 22, 24 and the drive side bearing chocks 28, 32 during the roll changing operation, as evident from FIG. 2, the drive side chocks 28, 32 are not provided with the usual dogs or other spacing means for supporting the upper drive side chock 28 on the lower chock 32 during movement of the roll assembly 20 along the rails 38, 40 and the aforementioned external rails.  
  In the operating position of the roll assembly 20 within the mill stand 42 the upper and lower bearing chocks 26, 28 and 30, 32 are stabilized by balancing plungers 50, 52 (FIG. 1) in the conventional manner. The work rolls 22, 24 are supported in the usual manner by back up rolls 54, 56 respectively when the work rolls are in their strip-engaging positions, as denoted by chain outlines 22a, 24a thereof.  
  As noted previously the aforementioned cantilevered support of the work rolls 22, 24 together with their drive side bearing chocks 28, 32 is highly&#39;desirable. During withdrawal or insertion of the roll assembly 20 a strip or sheet 54 (FIG, 2), supported for example at a constant pass line 56 (FIGS. 1 and 2), can unexpectedly remain within the several stands of a typical rolling mill. Thus, the necessity for cutting or tailing-out of the strip 54 and rethreading thereof, required in previous roll changing operations, is obviated by use of my novel roll assembly 20 or its equivalent.  
  One arrangement for the aforementioned cantilevered support of the upper work roll 22 and its drive side chock 28 includes a unique modification of the work side bearing chocks 26, 30 such that the upper work roll assembly including its bearing chocks 26, 28 can be supported entirely, and unexpectedly from the lower work side bearing chock 30 during insertion and withdrawal of the roll assembly 20 relative to the mill stand 42.  
  In furtherance of this purpose the lower work side chock 30 is provided with a spaced pair of upstanding arms 58, 60 disposed for slidably engaging complementary surfaces or slideways of the upper work side chock 26. Such surfaces are partially defined by a pair of depending arms 62, 64 secured to the upper work side chock 26 and similarly engaging slideways or other complementary surfaces of the lower chock 30. Slideways for the lower end portions of the upper chock arms 62, 64 are delimited, as better shown in FIG. 2, by the upstanding arms 58, 60 of the lower chock 30 and by wing portions 66 of chock cover 68 secured to the front of the lowerbearing chock 30. Clearance areas 70, 72 are provided on the side surfaces of the upper bearing chock to permit relative movement between the lower chock arms 58, 60 and the upper chock arms 62, 64 as denoted by chain outline 58a (FIG. 2) of the lower chock arm 58. Chain outline position 58A of the lower chock arm corresponds to the closed or operating positions 22a, 240 (FIG. 1) of the work rolls. The clearance areas 70, 72 are defined, in the illustrated case, by the upper ends of the lower chock arms 58, 60, the adjacent edges of the upper chock arms 62, 64 and the adjacent portions of the balancing overhangs 74 of the upper work side chock 26. Similar clearance areas can be provided on the lower chock 30.  
  As evident from the drawings the chock arms 58, 60 and 62, 64 are sufficiently heavily constructed, for example from low or intermediate carbon steel plate, to support the cantilevered mass of the upper roll assembly.  
  To minimize further the time consumed by the roll changing process. it is highly desirable to provide quickly activated and deactivated spacing means between the upper and lower workside chocks 26, 30 in order to space the upper and lower work roll assemblies, including respectively the work rolls 22, 24 and their drive side chocks 28, 32, as shown in FIG. 2. Thereafter the roll assembly can be quickly inserted or withdrawn relative to the sheet or strip 54 which remains threaded through the several stands of the rolling mill. One arrangement of such spacing means includes a pair of gravity dogs 76, 78 the upper portions of which are inserted respectively in recesses 80. 82 for pivotal mounting by means of pivot pins 84. A generous clearance aperture 86 is provided in each of the dogs 76, 78 for insertion of the associated pin 84 so that an upper projection of each of the dogs bears against an upper wall of the recesses 80, 82, as denoted by reference numerals 88, during operative engagement of the dogs 76, 78 with the lower work side chock 30, as denoted by the solid outlines of the dogs 76, 78 in FIG. I. When the spacing dogs 76, 78 are not in use, the lower portions thereof are extended respectively into recesses 90, 92 in the lower work side chock 30, as denoted by chain outlines 76a, 78a thereof in FIG. 1. The dogs 76, 78 are configured such that, in the inactive positions of the dogs 76, 78 their centers of gravity are disposed inwardly of vertical center lines 94 of the pivot pins 84. The dogs 76, 78 are in consequence, subject to biasing forces such that their lower end portions swing outwardly on release from the lower chock recesses 90, 92. When it is desired to activate the spacing dogs 76, 78 to space the work side chocks 26, the work side chocks are separated to their solid outline positions (FIG. 1). Separation of the work side chocks can be effected by a crane (not shown) or other suitable means if the roll assembly 20 is outside the mill stand 42, or if inside, by balancing plungers 50, 52 after first withdrawing mill clamps 96, 98 and back up rolls 54, 56. This separation is terminated when toe portions 100 of the spacing dogs 76, 78 just clear the lower chock recesses 90, 92 respectively. Outward movement of the spacing dogs 76, 78 including their toe portions 100 is terminated by heel or offset portions 102 thereof such that the toe portions rest squarely upon ledge surfaces of the lower chock 30 adjacent its dog recesses 90, 92.  
  After insertion of a new roll assembly 20 within the mill stand 42 the work side chocks 26, 30 are separated a slight additional distance by the plungers 50, 52 such that the toe portions 100 of the dogs 76, 78 stand clear of the lower chock 30 while the heel portions 102 thereof are still retained by the upper edge portions of the dog recesses 90, 92. Thereupon the mill clamps 96, 98 are moved inwardly to engage the chocks 26, 30 in the usual manner. During such inward movement a deflecting bar 104 on each mill clamp 96 or 98 engages the adjacent dog 76 or 78 and moves the same inwardly to its chain outlined position 76b or 78b. At the positions 76B, 783 the spacing dogs are aligned for insertion into the lower chock recesses 90, 92 respectively, when the opening between the work rolls 22, 24 are closed.  
  In operation, when it is determined that a roll change is necessary, the strip 54 running through the rolling mill including the stand 42 is stopped without, however. cutting the strip or otherwise removing the strip from the mill stand 42. If pre-reduction or post reduction operations (not shown) are employed with the rolling mill, a strip accumulator (not shown) of conventional design can be employed to store or to pay-off strip running through these operations. The upper and lower work rolls 22, 24 and their associated chocks are then separated to their solid outline positions shown in FIG. 1 by means of the roll balance plungers 50, 52.  
 I The drive spindles (not shown) at the drive side of the mill stand are jogged to position the drive flats thereof in a predetermined orientation. As the mill clamps 96, 98 are withdrawn together with the deflecting bars 104, the spacing dogs 76, 78 fall by gravity into their operative or solid outline positions of FIG. 1. The upper plungers 50 are then actuated to lower the upper work roll assembly including the upper work side chock 26 slightly so that the toe portions of the spacing dogs bearingly engage the lower work side chock 30 adjacent its recesses 90, 92. The opening between the upper and lower rolls 22, 24 (FIG. 2) is now sufficient to clear the strip 54 as the roll assembly 20 is withdrawn from the mill stand 42.  
  During insertion and withdrawal of the roll assembly 20 it is desirable to stabilize the cantilevered or drive side chock 28, which as noted above is rotatably mounted on the associated roll neck. One arrangement for so stabilizing the upper drive side chock 28 includes the aforementioned restraining bar 46, which can be slip-fitted insuitable apertures therefore extending through the upper bearing chocks 26, 28. Desirably the restraining bar 46 is hollow or otherwise contains a longitudinally extending passage 106 for the transfer of the lubricant therethrough between the upper bearing chocks 26, 28. Lubricant can be supplied from a suitable source,(not shown) detachably joined to a protruding extension 108 of the restraining bar 46 (FIGS. 2 and 3). The restraining bar 46 is closely fitted in the chock apertures therefor so that turning of the cantilevered chock 28 relative to the work side chock 26 is prevented.  
  A lubricant conduit 48 mentioned previously, can be similarly joined to the lower bearing chocks 30, 32 when it is desired to supply lubricant thereto in a similar manner. It is of course not necessary to restrain the lower drive side chock 32 relative to work side chock 30 beyond their engagement with the aforementioned rails. The rails provide a restraint serving essentially the same function as the bar 46.  
  The replacement roll assembly is moved into the mill stand 42 where the drive side roll necks enter the prepositioned drive spindles (not shown). The upper and lower work rolls 22, 24 and associated components of the replacement roll assembly 20 are spaced by the spacing dogs 76, 78 in the manner described previously such that the roll faces of the work rolls 22, 24 readily clear the strip 54 which has remained in the mill stand 42 as aforesaid. The top roll assembly is lifted slightly by the upper roll balance plungers 50, whereupon the mill clamp 96, 98 are engaged and simultaneously repositioned the spacing dogs 76, 78 to their chainoutlined attitudes 76b, 78b. The aforementioned lubrication lines are then connected to the workside chocks 26, 30. The balancing plungers 50, 52 and the back up rolls 54, 56 are then manipulated to bring the work rolls22, 24 into contact with the strip 54 at the constant pass line 56. The strip 54 is then restarted through the rolling mill while the aforementioned strip accumulator (if used) pays off or stores strip until normal operation is attained. As time permits the withdrawn roll assembly is removed to the roll shop where the upper roll and associated chocks can be disassembled from the remainder of the roll assembly by means of a crane or the like.  
  From the foregoing it will be seen that a novel and efficient Mill Roll Changing System Including A Cantilevered Roll Assembly 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. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, and joining means mounted entirely and normally permanently on said bearing chocks for detachably joining said second bearing chock to said first bearing chock so that said second bearing chock and in turn said second mill roll are supported entirely from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported without removing strip or the like from the mill stand.  
  2. The combination according to claim 1 including quick-deactivatable spacing means movably mounted on one of said bearing chocks for spacing said chocks and said rolls in a first position of said spacing means during said insertion and said withdrawal, and means for moving said spacing means to be inactive second position thereof to permit contact between said rolls and said strip when said roll assembly is positioned within said stand.  
  3. The combination according to claim 2 wherein said spacing means include at least one dog pivoted to one of said bearing chocks for engagement with the other of said chocks.  
  4. The combination according to claim 3 including said dog being configured such that the center of gravity thereof tends to pivot said dog to a position of engagement with said other chock.  
  5. The combination according to claim 4 including recess means in said other chock for receiving said dog in an inactive position thereof.  
  6. The combination according to claim 2 wherein said spacing means include a pair of spacing dogs pivoted to one of said bearing chocks and pivotable to positions of bearing and separating engagement with&#39; the other of said bearing chocks, and means for biasing said pivoted dogs towards the bearing engagement positions respectively.  
  7. The combination according to claim 1 including an additional bearing chock rotatably mounted adjacent the other end of said lower roll, rail means for supporting said roll assembly, and rail engaging means rotatably mounted directly on said first and said additional bearing chocks, said rail engaging means when engaging said rail means maintaining a predetermined attitude of said additional bearing chock relative to said first and said second bearing chocks.  
  8. The combination according to claim 7 including a lubricant conduit extending generally along said first roll and coupled to said first and said additional bearing chocks for supplying lubricant to at least one of said first and said additional chocks, said lubricant conduit having sufficient stiffness to restrain rotation of said additional chock relative to said first chock when the rail engaging means thereof are not engaged with said rail means.  
  9. The combination according to claim 1 wherein said detachably joining means include interfitting projection and recess means on said bearing chocks, said projection and recess means being slidably engageable so that said second bearing chock and said second roll can be supported at varying distances from said first bearing chock.  
  10. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported.  
 from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported Without removing strip or the like from the mill stand, an additional bearing chock rotatably mounted adjacent the other end of said second mill roll, and an elongated restraining member extending generally along said second mill rolland joined to said second bearing chock and to said additional bearing chock for maintaining a predetermined attitude of said additional chock relative to said first and said second bearing chocks.  
  11. The combination according to claim 10 including the provision of said restraining member in the form of a stiff conduit for conveying lubricant between said second bearing chock and said additional bearing chock.  
  12. The combination according to claim 11 wherein lubricant passage means for said chocks are extended through said restraining member.  
  13. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported without removing strip or the like from the mill stand, said joining means including a pair of arms secured to at least one of said bearing chocks and engaging slideways therefor on the other of said bearing chocks.  
  14. The combination according to claim 13 including the slideway means of at least one of said chocks being at least partially defined by a winged chock cover therefor.  
  15. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported without removing strip or the like from the mill stand, quick-deactivatable spacing means coupled between said bearing chocks for spacing said chocks and said rolls during said insertion and said withdrawal, means for deactivating said spacing means to permit contact between said rolls and said strip when said roll assembly is positioned within said stand, and mill clamp means on said mill stand. said deactivating means including a deflecting member on said clamp means and positioned for engaging and deactivating said spacing means upon closure of said mill clamp means upon said bearing chocks.  
  16. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported without removing strip or the like from the mill stand, an additional bearing chock rotatably mounted on each of said first and said second rolls adjacent the other ends thereof respectively, and restraining means extending between each of said first and said second bearing chocks and the associated additional bearing chock for maintaining a predetermined rotative attitude of each of said additional bearing chocks.  
  17. The combination according to claim 16 including lubricant conduit means extending from said first and said second bearing chocks to said additional bearing chocks respectively.  
  18. The combination according to claim 17 including said restraining means and said conduit means being quick-detachably joined to said chocks.  
  19. A mill roll assembly comprising a first mill roll, a first bearing chock rotatably mounted adjacent one end of said first roll, a second mill roll disposed generally above said first mill roll, a second bearing chock rotatably mounted adjacent one end of said second mill roll and disposed generally above said first bearing chock, means for detachably joining said second bearing chock to said first bearing chock so that said second mill roll and said second bearing chock are supported from said first bearing chock in cantilevered fashion whereby said roll assembly can be inserted and withdrawn relative to a stand of said mill while the assembly is so supported without removing strip or the like from the mill stand, quick-deactivatable spacing means coupled between said bearing chocks for spacing said chocks and said rolls during said insertion and said withdrawal, means for deactivating said spacing means to permit contact between said rolls and said strip when said roll assembly is positioned within said stand, said spacing means including a pair of spacing dogs pivoted to one of said bearing chocks and pivotable to positions of bearing and separating engagement with the other of said bearing chocks, means for biasing said pivoted dogs towards the bearing engagement positions respectively, a pair of mill clamps on said stand for clamping engagement with said bearing chocks in an operating position of said roll assembly within said stand, and deflecting members on said mill clamps respectively and positioned to move said dogs to inactive positions thereof against said biasing means upon movement of said clamps into engagement with said bearing chocks.  
  20. A mill roll and bearing assembly comprising a mill roll, a first bearing chock rotatably mounted adjacent one end of said mill roll, an additional bearing chock rotatably mounted adjacent the other end of said mill roll, and an elongated restraining member extending generally along said mill roll and joined to said first hearing chock and to said second bearing chock for maintaining a predetermined attitude of said second chock relative to said first bearing chock.  
  21. The combination according to claim 20 wherein said restraining member has a lubricant passage extending therethrough in communication with internal lubricant passages of said bearing chock.  
  22. The combination according to claim 20 wherein said restraining member is quick-detachably joined to said bearing chock.