Patent Publication Number: US-7219521-B1

Title: Rolling mill product handling system

Description:
BACKGROUND 
   1. Field of the Invention 
   This invention relates generally to continuous hot rolling mills producing long products such as bars, rods, and the like, and is concerned in particular with an improved product handling system for longitudinally receiving subdivided lengths of such products as they issue from the rolling mill, and for transferring the product lengths to a receiver which typically will comprise a cooling bed. 
   2. Description of the Prior Art 
   In known product handling systems, such as for example those described in U.S. Pat. No. 3,621,696 (Norlindh) and U.S. Pat. No. 4,307,594 (Steinbock), successive product lengths are received in guide channels provided in the surfaces of rotatable drums. The drums are rotated, either continuously or intermittently, to deliver the thus received product lengths to underlying cooling beds. 
   Continuous drum rotation requires complicated upstream switching systems and mechanisms to reliably deliver the product lengths into the continuously moving guide channels. On the other hand, intermittent drum rotation requires heavy duty drives to overcome system inertia during the stop/start sequences, as well as precise controls to insure that the guide channels are stopped in proper alignment with the delivery path of the incoming product lengths. 
   The objective of the present invention is to provide a product handling system that in comparison to known prior art systems, is less complicated and easier to coordinate and control. 
   SUMMARY OF THE INVENTION 
   A product handling system in accordance with the present invention comprises a support structure defining a pair of stationary inverted first channels with downwardly facing open sides. At least one cylindrical drum is interposed between each of the first channels and an underlying receiver. The drums are rotatable about their axes, with their surfaces arranged to close the open sides of the respective first channels. The drum surfaces are interrupted by second channels, with the first and second channels and the drum axes being arranged in a parallel relationship. Successive product lengths are alternately delivered longitudinally into one and then the other of the first channels. The drums are rotated about their axes resulting in the thus delivered product lengths being sequentially: (i) temporarily retained in the first channels by the rotating drum surfaces; (ii) deposited from the first channels into the second channels when the second channels rotate into radial alignment and communication with the first channels and (iii) downwardly deposited from the second channels to the receiver when the second channels rotate to discharge positions over the underlying receiver. 
   These and other features and attendant advantages of the present invention will now be described in further detail with reference to the accompanying drawings, wherein: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic plan view of a product handling system in accordance with the present invention; 
       FIG. 2  is a sectional view on an enlarged scale taken along taken along line  2 - 2  of  FIG. 1 ; and 
       FIGS. 3A to 3C  are views similar to  FIG. 2  depicting sequential stages in the handling of products received from the rolling mill. 
   

   DETAILED DESCRIPTION 
   With reference initially to  FIGS. 1 and 2 , a product handling system in accordance with a preferred embodiment of the present invention 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 includes a support structure  16  defining a pair of inverted first channels  18   a ,  18   b  with downwardly facing open sides. Cylindrical drums  20   a ,  20   b  are interposed between each of the first channels  18   a ,  18   b  and the cooling bed  14 . The drums are rotatable about their respective axes A 1 , A 2  with the drum surfaces arranged to close the open sides of the respective first channels. 
   Each drum surface is interrupted by at least one second channel  22   a ,  22   b  with the first channels  18   a ,  18   b , second channels  22   a ,  22   b  and drum axes A 1 , A 2  arranged in parallel relationship. 
   Long products such as bars, rods and the like exiting from the last mill stand  12  are directed by a switch  24  to a shear  26  for subdivision into shorter product lengths. The switch and shear act in concert in a known manner to alternatively direct the subdivided product lengths to one and then the other of a pair of guide pipes  28   a ,  28   b  having delivery ends aligned respectively with the first guide channels  18   a ,  18   b.    
   As can be best seen in  FIG. 1 , a plurality of the first and second drums  20   a ,  20   b  are aligned axially in series between each of the first channels  18   a ,  18   b  and the cooling bed. Drive motors  30  serve to rotate the drums of each series. 
   The drums may be rotated intermittently, but most preferable are rotated continuously, with the drums of one series being rotated in a direction opposite to that of the other series. 
   At the operational stage depicted in  FIG. 2 , a first bar b 1  has been delivered to the first channel  18   a  via guide pipe. The first channel is closed by the rotating surface of drum  20   a . The first bar is thus temporarily retained in the first channel while the other rotating first channel  22   b  remains empty as it approached the empty first channel  18   b . Drum  20   a  is rotating in a counter clockwise direction, and drum  20   b  is rotating in a clockwise direction. 
   At the stage depicted in  FIG. 3A , the second channel  22   a  has rotated into radial alignment and communication with first channel  18   a , allowing the first bar b 1  to be deposited in the second channel. The second channel  22   b  has rotated past the first channel  18   b , which has now received a second bar b 2 . 
   At the stage shown in  FIG. 3B , the second channel  22   a  containing the first bar b 1  has now rotated out of alignment with first channel  18   a , the latter again having again been closed by the drum surface and filled with a third bar b 3 . 
   At the stage shown in  FIG. 3C , the second channel  22   a  has rotated to a discharge position, allowing the first bar b 1  to be transferred downwardly to the cooling bed  14 . The second channel  22   b  of drum  20   b  is approaching the first notch  18   b , where it will pick up the second bar b 2  for delivery to the cooling bed as it continues to rotate to its discharge position. These sequences will be repeated to handle successively delivered product lengths. 
   The support structure  16  preferable includes shrouds  32   a ,  32   b  that partially envelop the drum circumferences from the first channels  18   a ,  18   b  to the respective discharge positions. 
   In light of the foregoing, it will be understood by those skilled in the art that various modifications of the above described system may be made without departing from the inventive concept defined by the appended claims. Non limiting examples of such modifications include, for example, the use of more than two parallel first channels acting in concert with the same number of drum series. Receivers other than cooling beds may serve to gather and/or transport product lengths being discharged from the respective second channels. Also, the drum surfaces may be provided with additional second channels.