Abstract:
A slab handling apparatus comprising a foundation structure, a plurality of longitudinally spaced buffer members positioned on the foundation structure, and a plurality of longitudinally spaced roller assemblies connected to the respective buffer members with a lost motion connection. The lost motion connections allow relative movement between the buffer members and the roller assemblies between a slab loading position in which the buffer members are supported on the foundation structure with upper edges thereof above the roller assemblies, whereby to allow the loading of a slab onto the upper edges without damage to the roller assemblies, and a slab slitting position in which the roller assemblies are above the upper edges of the buffer members, whereby to allow the roller assemblies to rollably support the slab to facilitate selective longitudinal adjustment of the slab to accommodate the slab slitting operation.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims the priority of U.S. Provisional Patent Application No. 60/507,429, filed on Sep. 30, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     This invention relates to slab slitting apparatus and more particularly to an apparatus for facilitating the handling of heavy steel slabs during a slab slitting operation.  
         [0003]     Slabs emanating from a continuous casting mill are typically cut into slabs which are thereafter selectively slit to produce the desired final slab division.  
         [0004]     One prior art slab slitting procedure utilizes a slitting apparatus including a bed of rollers and a plurality of oxy torches movable selectively relative to the roller bed. A slab to be slit is loaded onto the roller bed whereafter the slab and torches are relatively adjusted to position the torches at desired predetermined locations for the slitting operation. Whereas this procedure is generally satisfactory, there is a problem in that the slabs, which can be extremely heavy, may inflict major damage to the rollers as the slabs are loaded onto the rollers, necessitating extensive equipment downtime and expensive repairs.  
       SUMMARY OF THE INVENTION  
       [0005]     This invention is directed to an improved slab handling apparatus and procedure.  
         [0006]     More specifically, this invention is directed to a slab handling apparatus in which any equipment damage and consequent downtime and repair are minimized.  
         [0007]     The slab handling apparatus of the invention includes a foundation structure; a plurality of longitudinally spaced buffer members positioned on the foundation structure; and a plurality of longitudinally spaced roller assemblies connected to the buffer members with a lost motion connection allowing relative movement between the buffer members and the roller assemblies between a slab loading position in which the buffer members are supported on the foundation structure with upper edges thereof above the roller assemblies and a slab slitting position in which the roller assemblies are above the upper edges of the buffer members. With this arrangement a slab may be loaded onto the upper edges of the buffer members without damage to the roller assemblies whereafter the roller assemblies and buffer members may be relatively moved by virtue of their lost motion connection to the slab slitting position where the roller assemblies support the slab to facilitate selective longitudinal adjustment of the slab to accommodate the slab slitting operation.  
         [0008]     According to a further feature of the invention, each lost motion connection comprises a vertical slot receiving a pin, the pin moving vertically in the slot as the buffer member moves relative to the roller assembly between the loading and slitting positions. In the disclosed embodiment of the invention, the pins are carried by the roller assemblies and the slots are provided in the buffer members.  
         [0009]     According to a further feature of the invention, the apparatus further includes a table defining a window and mounted for pivotal movement between a generally horizontal slab loading position in which the slab window overlies the foundation structure and an upwardly tilted, slab slitting position; the roller assemblies are mounted in longitudinally spaced relation on the table and the buffer members are supported in longitudinally spaced relation on the table by the lost motion connections between the roller assemblies and the buffer member; and with the table in the horizontal slab loading position, the buffer members are positioned in the table window and are supported on the foundation structure.  
         [0010]     According to a further feature of the invention, the table includes a pair of parallel longitudinally extending guide rails; and each roller assembly includes a pair of laterally spaced guide blocks slidably guided on the respective guide rails, a beam structure extending laterally between the guide blocks, and a roller structure extending laterally between the guide blocks in overlying relation to the beam structure and journaled at opposite ends thereof on the respective guide blocks.  
         [0011]     According to a further feature of the invention, each buffer member comprises an upstanding plate supported on the foundation structure with the apparatus in the slab loading position and each lost motion connection comprises a plurality of laterally spaced pins projecting from a beam structure of a roller assembly and received in a respective plurality of vertical slots provided in a buffer member plate.  
         [0012]     According to further feature of the invention, each buffer member comprises forward and rearward longitudinally spaced and coupled upstanding plates flanking a respective roller assembly and each lost motion connection comprises a plurality of laterally spaced pins projecting forwardly and rearwardly from the beam structure of the respective roller assembly and received in a respective plurality of vertical slots in the forward and rearward plates of the buffer member.  
         [0013]     According to further feature of the invention, each roller structure comprises a pair of longitudinally spaced rollers journaled at opposite ends on the guide blocks and each roller assembly further includes an upwardly directed torch position between the longitudinally spaced rollers and means operative to move the torch laterally between the rollers to achieve the slitting operation.  
         [0014]     According to further feature of the invention, the beam structure of each roller assembly comprises a pair of laterally extending and longitudinally spaced beams and each torch extends upwardly between a pair of beams and between a pair of rollers of the respective roller assembly.  
         [0015]     According to further feature of the invention, the apparatus further includes a deburring device positioned in opposition to each torch and movable laterally with the torch to achieve the slitting operation.  
         [0016]     According to further feature of the invention, the apparatus further includes a gantry mounted on the table and including a central bar portion extending longitudinally on the table, and the deburring devices are slidably mounted on the gantry central bar portion in longitudinally spaced relation.  
         [0017]     According to further feature of the invention, the apparatus further includes means for moving the gantry laterally relative to the table whereby to allow the deburring devices to be moved to a location clear of the rollers to allow the loading of a slab onto the rollers and thereafter moved laterally in synchronization with the associated torches to accomplish the slitting operations.  
         [0018]     According to further feature of the invention, the apparatus further includes means for raising and lowering the gantry relative to the table.  
         [0019]     Other applications of the present invention will become apparent to those skilled in the art when the following description of the best mode contemplated for practicing the invention is read in conjunction with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]     The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:  
         [0021]      FIG. 1  is a perspective view of a slab handling apparatus according to the invention;  
         [0022]      FIG. 2  is a somewhat schematic, cross-sectional view of the apparatus of  FIG. 1 ;  
         [0023]      FIG. 3  is a perspective view of a roller and buffer assembly utilized in the apparatus of  FIG. 1 ;  
         [0024]      FIG. 4  is an elevational view of the roller and buffer assembly;  
         [0025]      FIG. 5  is a plan view of the roller and buffer assembly;  
         [0026]      FIG. 6  is a cross sectional view taken on line  6 - 6  of  FIG. 5 ;  
         [0027]      FIG. 7  is a perspective view of a beam structure utilized in the roller assembly;  
         [0028]      FIGS. 8 and 9  are schematic views illustrating the operation of the roller and buffer assembly;  
         [0029]      FIGS. 10, 11 , and  12  are fragmentary, detail views of specific aspects of the handling apparatus; and  
         [0030]      FIG. 13  is a schematic view of a portion of the handling apparatus. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]     The invention slab handling apparatus  10 , broadly considered, includes a base assembly  12 , a table assembly  14 , a pivot assembly  16 , a deburring assembly  18 , torches  20 , and a foundation  22 .  
         [0032]     Base assembly  12  is shown schematically and includes spaced base members  24  and  26  adapted to be fixedly secured to a support structure or floor.  
         [0033]     Table assembly  14  includes end plates  14   a  and  14   b ; side plates  14   c  and  14   d ; a top plate  14   e  defining a rectangular window  14   f , guide rails  28  spaced above top plate  14   e  and running longitudinally along opposite sides of the table assembly proximate side plates  14   c  and  14   d,  respectively; a plurality of roller assemblies  30  positioned slidably on guide rails  28 ; and a plurality of buffer assemblies  31 .  
         [0034]     Each roller assembly  30  includes guide blocks  32  and  33  slidably mounted on respective guide rails  28 ; a beam structure  34  extending between the guide blocks; a pair of longitudinally spaced laterally extending rollers  35  journaled at their opposite ends on guide blocks  32  and  33 ; and a pair of vertical cushions  36  mounted on brackets  37  carried by guide block  33 .  
         [0035]     Beam structure  34  includes a pair of I beams  38  and  39  extending laterally between the guide blocks and spaced longitudinally to define a vertical channel or space  40  therebetween. A plurality of pins  41  extend rearwardly from the web  38   a  of rear I beam  38  and a plurality of pins  41  extend forwardly from the web  39   a  of front I beam  39 .  
         [0036]     Each roller assembly is selectively movable along guide rails  28  by electric motors  42  mounted on the underface of guide blocks  32  and  33  and including pinions  42   a  drivingly engaging longitudinally extending racks  43  provided on top plate  14   e  on opposite sides of the table.  
         [0037]     Each buffer assembly  31  has “U” configuration in cross-section and includes front and rear plate members  46  and cross members  48 . Each plate member  46  has an “E” configuration and the lower ends of each bar  46   a  of the “E” are connected by a respective cross member  48 . Each bar  46   a  of the “E” of each plate member includes a vertical slot  46   b  receiving a pin  41  carried by beam structure  34  whereby to provide a lost motion connection between the buffer assembly and the roller assembly. Specifically, the pins  41  extending rearwardly from the web  38   a  of the rear beam  38  are received in the slots  46   b  defined by the rear plate member  46  and the pins  41  extending forwardly from the web  39   a  of the front plate member  39  are received in the slots  46   b  defined by the front plate member.  
         [0038]     Pivot assembly  16  includes a pair of hydraulic rams  50  proximate each base member  24  and  26  between the respective base member and a table end plate  14   a ,  14   b , and a pair of links  51 ,  52  proximate each end of the table assembly. The piston rod  50   a  of each ram  50  is pivotally connected to a pivot pin  14   i  carried by a respective end plate  14   a ,  14   b  and the other end  50   b  of the ram is pivotally secured to a pin  24   a ,  26   a  carried by a respective base member  24 ,  26 . Each link  51  is pivotally secured at its lower end to a respective base member  24 ,  26 ; each link  52  is pivotally secured at its upper end to a respective end plate  14   a ,  14   b ; and the inboard ends of the links are pivotally secured at  53 .  
         [0039]     Table assembly  14  is pivotally secured to tower portions  24   a ,  26   a  of the base members  24 ,  26  by pivot pins  60  carried by end plates  14   a ,  14   b  and spaced from the pivot axes of the pins  14   i . The parameters of the various aspects of the table assembly are chosen such that contracting movement of the rams  50  has the effect of pivoting the table assembly upwardly about the axes of pins  60  with the extent of upward movement being determined and delimited by run out of the rams and/or by ultimate alignment of links  51  and  52 . For example, the parameters may be chosen such that the table is pivoted upwardly in response to the contraction of the rams to a position in which the upper face of the table lies in a primary plane at an angle α of between 10° and 20° from the vertical plane.  
         [0040]     Deburring assembly  18  includes a gantry assembly  62  and a plurality of deburring devices  64 . Gantry assembly  62  has a “U” configuration including a central horizontal bar portion  62   a  and vertical end bar portions  62   b . Each vertical end bar portion  62   b  is slidably received in a sleeve structure  65  which is slidably mounted on a guide rail  66  mounted on a respective end plate  14   a ,  14   b . An electric motor  67  carried by each sleeve structure includes a pinion  68  engaging a rack  70  mounted on a respective end plate  14   a ,  14   b  whereby to move the sleeve  64  and thereby the gantry along the guide rails  66  in response to actuation of motors  67 . A further electric motor  71  carried by each sleeve structure  65  includes a pinion  72  engaging a rack on the respective end bar portion  62   b  whereby to raise and lower the gantry relative to the sleeve structures  65 .  
         [0041]     Each deburring device  64  includes a sleeve bracket  73  slidably mounted on the horizontal portion  62   a  of the gantry and a deburring device  74  carried by the sleeve bracket and positioned between the rollers  35  of a respective roller assembly  30 .  
         [0042]     A torch  20  is carried by each roller assembly  30  with the torch positioned between the rollers  35  and between I beams  38  and  39 . Torch  20  is carried by a torch bracket  76  which is in turn secured to a ball screw member  78 . Ball screw member  78  is driven in known manner by a screw shaft  80  driven by an electric motor  82  secured to the underface of guide block  32 . The free end of screw shaft  80  is journaled in a bearing  84  positioned on the underface of guide block  33  and ball screw member  78  is mounted on and guides along a downward extension  38   b  of the web  38   a  of beam  38 .  
         [0043]     Foundation  22  is positioned in general underlying conformity with window  14   f  so that, with the table in its horizontal or rest position, base members  46   c  of the buffer structures  36  may rest on the upper face  22   a  of the foundation slab with the various parameters chosen such that, with the table at rest and the base members  46   c  positioned on the upper face  22   a  of the foundation member, the pins  41  are in the lower ends of the respective slots  46   b.    
       OPERATION  
       [0044]     With the handling apparatus in the horizontal or lowered position seen in  FIGS. 1 and 2  and in solid lines in  FIG. 8 , and with the deburring gantry positioned in a lowered position essentially behind table assembly end plate  14   c , a slab S is delivered to the upper face of the table utilizing, for example, an overhead crane employing a magnetic grabber. Previous to such delivery the various roller assemblies  30  have been selectively moved along the guide rails  28  (either manually or by suitable power means  42 / 43 ) to approximate the location of the various cross cuts or slits that are to be made in the slab. The deburring devices  64  are moved along with the roller assemblies to maintain each deburring device  74  in alignment between a respective pair of rollers  35  and thereby in vertical alignment with the torch carried by the respective roller assembly. The deburring devices may be moved manually and separately or, as seen in  FIG. 11 , an indexing finger  73   a  may be provided in association with each sleeve bracket  73  for engagement in a notch  32   a  provided in a bracket  32   b  carried by the upper face of each guide block  32  so that lateral movement of the roller assemblies along the guide rails  28  with the gantry in a lowered position has the effect of moving the deburring devices with the associated roller assemblies so that vertical alignment of each deburring device  74  with its respective torch  20  is always maintained.  
         [0045]     With the table in the horizontal position and the base members of the buffer devices supported on the upper face of the foundation slab  22 , the upper edges  46   d  of the side plates  46  of the buffer devices are positioned above the upper surfaces of the rollers  35  so that, as a slab S is lowered into position on the table, the slab engages the upper edges  46   d  of the buffer devices and there is no contact between the slab and the rollers  35  and therefore no opportunity for a heavy, dropping slab to damage the rollers. After the slab has been positioned on the upper edges  46   d  of the buffer assemblies, the rams  50  are contracted whereby to rotate the table about the axes of the pins  60 . As the table rotates upwardly, and as schematically seen in the dash line position of  FIG. 8 , the base members of the buffer devices lift off from the foundation member and the buffer members move downwardly relative to the rollers  35  by virtue of the lost motion connection provided by the pins  41  and the elongated slots  46   b  so that the rollers move into engagement with the lower face of the slab and the rollers assume the full weight of the slab. This partially raised position is seen in dash lines in  FIG. 8 . In this partially raised position on the table, the position of the roller assemblies along the length of the slab may be fine tuned by vernier movement of the roller assemblies along the guide rails to effect the final precise locations of the cross cuts to be accomplished on the slab. This vernier adjustment of the roller assemblies is achieved by selective energization of motors  42  in coaction with racks  43 . As the vernier adjustment of the roller assemblies is accomplished, and assuming the use of the indexing arrangement of  FIG. 11 , the deburring devices  74  undergo a corresponding vernier adjustment whereby to maintain their central location relative to a respective pair of rollers  35  whereafter the gantry is raised in the sleeves  64  to disengage the indexing fingers  73   a  from the notches  32   a . The upward pivotal movement on the table is now resumed and the table is moved upwardly to its fully upwardly tilted position seen in  FIG. 9 .  
         [0046]     At this time the respective deburring devices  74  and torches  20  are moved in synchronization downwardly along the slab between the respective roller pairs  35  to effect the several cross cuts of the slab with each torch  20  (utilizing for example oxygen and natural gas provided by conduits  90 ) coacting in known manner with a respective deburring device  74  (utilizing for example oxygen provided by a conduit  92 ) to achieve a clean kerf with minimal slag. The movement of the torches is achieved by energization of screw drive motors  82  and the synchronized movement of the deburring devices is achieved by energization of motors  67 . Following the cutting operation the rams  50  are extended to pivot the table downwardly about the axes of pins  60  to the horizontal position. As the table arrives in the horizontal position, the foundation members  46   c  of the buffer devices  44  re-engage the upper face  22   a  of the foundation block to move the buffer devices upwardly relative to the associated rollers  35  by virtue of the lost motion connection provided by the pins  41  and the elongated slots  46   b  so that, as the table reaches the horizontal position, the slab is again supported on the upper edges  46   d  of the buffer devices whereafter the overhead crane and magnetic grabbers may again be employed to remove the cut slab sections from the table whereafter another slab may be loaded onto the upper edges of the buffer devices preparatory to a new slitting operation.  
         [0047]     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is permitted under the law.