Abstract:
A rolling mill rotating entry system (RES) with at least one front end-driven drum that indexes alignment of the RES guide path and drum with the bar stock transfer guide path. The front end drive system is offset from the bar stock transfer path, so that the bar stock has sufficient clearance to enter the guide path. The front end drive system facilitates desired indexed alignment of the RES guide path and the bar stock transfer path without the need for front end braking or damping systems that are customarily used with rear driven drums in known RES systems. Other RES embodiments include a rear drive system that drives the drum in tandem with the front drive system.

Description:
CLAIM TO PRIORITY 
       [0001]    This application claims the benefit of co-pending U.S. provisional patent application entitled “RES WITH FRONT END OR FRONT AND REAR DRIVE SYSTEM”, filed Sep. 23, 2011, and assigned Ser. No. 61/538,340, which is incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    1. Field 
         [0003]    Embodiments of the present invention relate to a rotating entry system (RES) type of product handling system in a bar mill that produces long bar or rod products, wherein as part of a bar handling system the RES can receive long bar product from the rolling mill and then deliver the product onto a cooling bed. More particularly embodiments of the present invention relate to RES front end drive systems, alone or in combination with rear drive systems. 
         [0004]    2. Description of the Prior Art 
         [0005]    A conventional known rotating entry system (RES)-type product handling system is shown and described in U.S. Pat. No. 7,219,521, issued May 22, 2007, the entire contents of which is incorporated by reference herein. As shown in  FIGS. 1 and 2  herein, a conventional known rotating entry system-type (RES) product handling system  10 , has one or more guide channels  18   a,    18   b  with corresponding rotatable drums  20   a,    20   b,  typically about 90 meters (291 feet) long; a support structure  16 ; and a drive motor  30  for each drum that is located at the exit end of the RES. Known RES apparatus locates the drum drive  30  at the rear or downstream end of the drum, for concentric alignment of the drive and its corresponding driven drum shaft A l , A 2 . A concentrically aligned drive cannot be utilized at the front upstream or loading end of the drum as it would block the rolled bar transfer path leading into the guide channel  18   a ,  18   b.    
         [0006]    In the known RES apparatus of  FIGS. 1 and 2 , each drum has at least one drum channel  22   a,    22   b  formed. within the outer drum periphery parallel to its corresponding guide channel  18   a,    18   b.  Each drum  20   a,    20   b  may have a plurality of drum channels  22   a,    22   b : for example four oriented 90° intervals about the drum circumference. During mill operation, a rolled bar enters one of the guide channels  18   a,    18   b  in its receiving position. After the entire bar is inside its corresponding guide  18   a,    18   b  the corresponding rotatable drum  20   a,    20   b,  driven by a rear end motor  30 , rotates and stops to a receiving position to accept the bar in a corresponding drum channel  22   a,    22   b.  Thereafter the drum  20   a,    20   b  rotates to a discharge position—typically at about 90 degrees from its receiving position—to discharge the bar to underlying cooling beds  14 . At the end of the start/stop (or indexing) sequence of the drum  20   a,    20   b,  the adjacent guide channels  18   a,    18   b  are at the receiving position for the next coming bar after time gap of a few seconds The rotatable drum  20   a,    20   b  includes more than 10 modular sub-assemblies that are connected in-line by couplings. A typical six-meter (20 feet) long modular sub-assembly has guide channels mounted on a rotating shaft A 1 , A 2  that is supported by roller bearings (not shown). 
         [0007]    The typical 90 degree indexing of the rotatable drum  20   a,    20   b  during operation occurs in up to a few seconds to meet high tonnage production requirement. For a rear end drive  30  RES, the front end receiving guide can experience a phase lag delay in rotation indexing during an indexing operation performed by the rear drive. The phase lag is attributable to the lengthy rotatable drum, which can be modeled analytically as a series of torsional spring and inertia systems. Due to the delay and the short time indexing the front end of the drum  20   a,    20   b  tends to oscillate, which may cause indexing misalignment between the incoming bar and its corresponding guide channel  18   a,    18   b . If gross indexing misalignment occurs the incoming bar may cobble and block the bar transfer path when its front end misses its corresponding guide channel  18   a,    18   b,  leading to production disruption until the cobbled bar is removed from the bar transfer path. In known RES apparatus drum/guidepath misalignment is suppressed via a damping or a braking mechanism (not shown). The braking or damping systems help reduce or control drum front end oscillation, but they do not prevent such oscillation. Such braking or damping systems add construction and service complexity to the RES apparatus. 
       SUMMARY 
       [0008]    Accordingly, embodiments of the present invention include an RES with a front end-driven drum that indexes alignment of the RES guide path and drum with the bar stock transfer path. The front end drive system is in an offset orientation from the bar stock transfer path, so that the bar stock has sufficient clearance to enter the guide path. In some embodiments the front end drive system incorporates pass-through slots aligned with the bar stock transfer path, for through passage of the stock. Other RES embodiments of the present invention include a rear drive system that drives the drum in tandem with the front drive system. 
         [0009]    More specifically embodiments of the present invention include a rolling mill rotating entry system, having a drum rotatable about an axis. The drum has a front axial end and a rear axial end, and at least one drum channel capable of receiving stock translated into the drum from the front to rear ends along a downstream transfer path that is established when the drum is rotated to a loading position and discharging stock from the drum channel when the drum is rotated to a discharge position. The system also has a drive coupled to the drum proximal the front axial end thereof, for rotating the drum. The drive is oriented offset from and not impeding the stock downstream transfer path. 
         [0010]    Another exemplary embodiment of the present invention includes a rolling mill rotating entry system, comprising coupled in series: a roll stand for translating rolled stock along a transfer path; a stock shear and transfer switch for respectively shearing stock to a desired length and selectively continuing stock translation along at least one downstream transfer path; a guide structure for guiding stock translation along the downstream transfer path; a drum rotatable about an axis; and a cooling bed for receiving stock discharged from the drum. The drum has a front axial end in proximity to the guide structure and a rear axial end, and at least one drum channel capable of receiving stock translated from the front to the rear end along the downstream transfer path when the drum is rotated to a loading position and discharging stock from the drum channel when the drum is rotated to a discharge position. A drive is coupled to the drum proximal the front axial end thereof, for rotating the drum, with the drive oriented offset from and not impeding the stock transfer path. 
         [0011]    Yet another exemplary embodiment of the present invention includes a rolling mill rotating entry system, comprising coupled in series: a roll stand for translating rolled stock along a transfer path; a stock shear and transfer switch for respectively shearing stock to a desired length and selectively continuing stock translation along a plurality of downstream transfer paths; a plurality of respective guide structures corresponding to each downstream transfer path for guiding stock translation along said downstream transfer path; a plurality of respective drums corresponding to each downstream transfer path; and a cooling bed for receiving stock discharged from at least one respective drum. Each drum is rotatable about an axis, having a front axial end in proximity to the respective guide structure and a rear axial end. Each drum has at least one drum channel capable of receiving stock translated from the front to the rear end thereof along the downstream transfer path when the drum is rotated to a loading position and discharging stock from the drum channel when the drum is rotated to a discharge position. A drive is coupled to at least one respective drum proximal the front axial end thereof, for rotating the respective drum. The drive is oriented offset from and not impeding the stock downstream transfer path. 
         [0012]    Further features of embodiments of the present invention, and the advantages offered thereby, are explained in greater detail hereinafter with reference to specific embodiments illustrated in the accompanying drawings. The features of the present invention may be applied jointly or severally in any combination or sub-combination by those skilled in the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0013]    The teachings of the present invention can be readily understood by considering the following detailed description in conjunction with the accompanying drawings, in which: 
           [0014]      FIG. 1  illustrates a schematic plan view of a known RES; 
           [0015]      FIG. 2  illustrates a sectional elevational view of the known RES of  FIG. 1 , taken along  2 - 2  thereof; 
           [0016]      FIG. 3  illustrates a schematic plan view of an RES, in accordance with an exemplary embodiment of the present invention; 
           [0017]      FIG. 4  illustrates a partial plan view of front end drive and driven rotatable drum portions of an RES, in accordance with an exemplary embodiment of the present invention; 
           [0018]      FIG. 5  illustrates a partial elevational view of front end drive and driven rotatable drum portions of FIG.  4 , in accordance with an exemplary embodiment of the present invention; 
           [0019]      FIG. 6  illustrates a front elevational view of a front end drive and guide bracket assembly of the RES of  FIGS. 4 and 5 , in accordance with an exemplary embodiment of the present invention; 
           [0020]      FIG. 7  illustrates a partial cutaway front elevational view of a front end drive of  FIG. 6  without the guide bracket assembly, in accordance with an exemplary embodiment of the present invention; 
           [0021]      FIG. 8  illustrates a radial cross sectional view of the support structure and driven rotatable drum portions of  FIGS. 4 and 5 , taken along  8 - 8  of  FIG. 4 , in accordance with an exemplary embodiment of the present invention; 
           [0022]      FIG. 9  illustrates a cross sectional view of the front end drive and driven rotatable drum portions of  FIGS. 4 and 5 , without the guide bracket assembly, in accordance with an exemplary embodiment of the present invention; 
           [0023]      FIG. 10  illustrates a schematic plan view of an RES with front and rear drive systems, in accordance with an exemplary embodiment of the present invention; and 
           [0024]      FIG. 11  illustrates a schematic plan view of an RES with front and rear drive systems, in accordance with another exemplary embodiment of the present invention. 
       
    
    
       [0025]    To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. 
       DETAILED DESCRIPTION 
       [0026]    To facilitate an understanding of embodiments, principles, and features of the present invention, they are explained hereinafter with reference to implementation in illustrative embodiments. In particular, they are described in the context of being a rotating entry system (RES) in a rolling mill. After considering the following description, those skilled in the art will clearly realize that the teachings of the present invention can be readily utilized in an RES front end drive system. Aspects of the present invention can provide a front end drive rotating entry system (RES) to reduce, if not eliminate, front end oscillation caused by a known rear-end drive RES, and thus enable a smooth and reliable receiving discharging operation. Embodiments of the present invention can index the rotatable drum with two synchronized drive systems mounted one at the front and one at the rear end of an RES. 
         [0027]    RES Subsystem Operational Overview 
         [0028]    With reference initially to  FIG. 3 , in accordance with a preferred embodiment of the present invention a front end drive RES product handling system and its associated bar stock transfer path is generally depicted at 10′ between the last roll stand  12  of a rolling mill and a receiver comprising a conventional carryover cooling bed  14 . The system  10 ′ includes a support structure  16 . At least one rotatable drum (here two drums  20   a,    20   b ) are interposed between the support structure  16  and the cooling bed  14 . The drums  20   a,    20   b  are rotatable about their respective shafts, referenced by axes A 1 , A 2 . Long products such as bars, rods and the like exiting from the last roll stand  12  are directed along a transfer path by a switch  24  to a shear  26  for subdivision into shorter product lengths. The switch  24  and shear  26  act in concert in a known manner to direct the subdivided product lengths along respective downstream transfer paths alternatively to one and then the other of a pair of guide pipes  28   a,    28   b,  having delivery ends aligned respectively with the drums  20   a,    20   b.  As described below, the rotating drums  20   a,    20   b  transfer bar stock product from the guide pipe  28   a,    28   b  outlets to the cooling bed  14 , completing the downstream transfer path. 
         [0029]    As further shown in  FIG. 3 , the front end drive RES  10 ′ in accordance with the present invention includes at least one rotatable drum (here two drums  20   a,    20   b ), each with a corresponding drum channel (not shown) for receipt of bar stock that is fed along a respective downstream transfer path, a support structure  16 , and a corresponding front-end drive system  40 . The front-end drive system  40  can be mounted on a support structure  16  either above or under the corresponding rotatable drum  20   a,    20   b,  offset from the bar stock transport or transfer guide path. With a front end drive  40  RES, oscillation experienced by a drum  20   a,    20   b  front end and its corresponding channel as compared to that of a known rear-end drive RES apparatus is reduced, if not eliminated. After an indexing sequence, an adjacent guide and drum channel can be positioned precisely at their relative receiving position—at the shortest possible time due to a lower (if not functionally insignificant) time delay—as compared to a known rear-driven RES  10  of  FIG. 1 . In embodiments of the present invention any relative oscillation of a drum and associated drum channel now occurs at the rear end of the RES  10 ′, and thus does not affect bar stock receiving/discharging operation, because the bar stock is only ejected circumferentially/laterally out of the drum&#39;s open exposed drum channel onto the cooling bed  14 . Damping or braking mechanisms, previously utilized in known RES apparatus to suppress front drum and guide relative oscillation, are not needed when practicing the present invention. Elimination of such mechanisms reduces RES manufacturing cost, increases potential operational reliability and simplifies the system. 
         [0030]    Further embodiments of the present invention, shown in  FIGS. 11 and 12  can index the rotatable drums  20   a ,  20   b  with two tandem synchronized drive system motors: a first drive system/motor  40  mounted at the front and a second drive system ( 30  or  40 ′) mounted to the rear of the RES, to obtain a stable operation with increased tonnage production demand and lower operating load on each tandem drive ( 40  front drive/ 30  or  40 ′ rear drive) than would be handled by a single drive. 
         [0031]    RES Front End Drive Structure 
         [0032]    Referring to  FIGS. 4-10  each individual modular drum  20   a,    20   b  section is a known, fabricated structure of circumferentially arrayed, parallel, and generally U-shaped open-ended drum channels  22   a,    22   b  that are affixed to and axially aligned with rotating drum shafts (designated by respective rotational axes A l  and A 2 ). As shown in  FIG. 8 , the modular drum sections are aligned and coupled together axially in tandem in known fashion to form the complete drum structures  20   a,    20   b.  The respective first and second drums  20   a,    20   b  are aligned axially and in series between its respective corresponding guide pipe  28   a,    28   b  discharge outlet and the cooling bed  14 . As shown in  FIG. 8 , channel guides  18   a,    18   b  are offset from and abut drums  20   a,    20   b,  in order to block the open ends of the corresponding drum channels  22   a,    22   b  between the bar stock loading and dropping positions, so that the bar stock product transported therein does not drop prematurely from the drum channels. 
         [0033]    In the present invention embodiment the drums  20   a ,  20   b  relative rotation and indexing operations are performed by a front end drive  40  that is coupled to and separately drives each respective drum shaft A 1 , A 2  proximal the drum axial front end (i.e., the portion of the bar stock transfer path that is upstream of the drum). The drums  20   a,    20   b  and their corresponding guide pipes  28   a,    28   b  outlets, are aligned for receipt of bar stock in the drum channels  22   a ,  22   b,  in a loading position that constitutes a portion of the bar stock transfer path. The front end drive  40  rotates the drums  20   a,    20   b  to their respective discharge or dropping positions for subsequent transfer dropping/discharge of the stock to the cooling bed  14 . The drums  20   a,    20   b  respective indexing and timing sequences for loading and discharging stock are performed by the front end drive  40  in a similar fashion as was performed by the known rear end drive  30  described in U.S. Pat. No. 7,219,521, that is incorporated by reference herein. 
         [0034]    As previously noted the front end drive  40  is oriented offset from the bar stock transfer path between the guide pipes  28   a,    28   b  and their corresponding drums  20   a,    20   b . Referring to  FIGS. 4-10 , the front end drive  40  includes a drive support structure and shroud  42  that is coupled to the RES support structure  16 . The drive includes a pair of servo motors  44 , each of which separately drives one of the drums  20   a,    20   b  via a separately dedicated gear train  46 . The servo motors  44  drive the drums  20   a,    20   b  in previously described step-like start/stop fashion. Within each gear train  46  the drive gear  48 , of known construction, is coupled to the servo motor  44  and transfers rotational power to driven gear  52  through intermediate gear  50 . One or more intermediate gears may be incorporated in the gear train between the drive gear  48  and driven gear  52 . A suitable gear ratio between the drive gear  48  and driven gear  52  is 40:1. Each driven gear  52  is coupled to its respective drum shaft A 1 , A 2  and defines axial pass-through slots  54  within its hub structure corresponding to the number and radial orientation of drum channels  22   a,    22   b.  The individual slots  54  are in communication with its corresponding drum channel  22   a,    22   b  as well as the outlet portions of the guide pipes  28   a,    28   b.    
         [0035]    The previously described components and materials herein as making up the various embodiments are intended to be illustrative and not restrictive. Many suitable components and materials that would perform the same or a similar function as the materials described herein are intended to be embraced within the scope of embodiments of the present invention. While embodiments of the present invention have been disclosed in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention and its equivalents, as set forth in the following claims.