Abstract:
An alignment device for aligning guiding apparatus with the main axis of a rolling mill comprising a camera and a video display communicating with the camera. The camera is mounted in the steel mill at the position of the guiding apparatus and the camera is moved until it is on the axis of the mill. The camera is then removed to a bench which duplicates the physical characteristics of the mill. The guiding apparatus is mounted on the bench adjacent the camera. The guiding apparatus is physically moved until it is located on the camera axis, which is the mill axis. The guiding apparatus is then remounted in the mill.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Multi-stand rolling mills require critical alignment of the reducing rolls and the guiding devices which feed the work product to the reducing rolls. If for some reason, misalignment between the guide and reducing rolls occurs during a rolling process, the result is often a damaged or “off-gauge” product which may not be marketable. It is therefore essential to have the guiding device in exact alignment with the reducing rolls during a reduction process. Because of the location of the main reducing rolls and the low light levels existing at this location, the adjustment of the guide rolls to their proper setting can present a challenge to a mill technician.  
         [0002]     Rolling mills traditionally present an environment which tends to be hostile for most alignment instruments. Usually alignment of the guides and reduction rolls must be accomplished in the shortest possible time under conditions which are less than ideal. The mill usually operates at an elevated temperature with coolant water being copiously applied to the surface of the guide rolls and the reduction rolls.  
         [0003]     In most instances the “throat” of the guide is obscured by auxiliary apparatus and the levels of light existing at the guide throat and the main roller “nip” leaves a lot to be desired.  
         [0004]     It is therefore seen that even if one was able to adjust the alignment of the guide and its rollers to the correct position to feed the reduction rolls of the mill, the adjustment procedure places an almost impossible task on the mill technician due to the fact that the critical zones of the mill i.e. the main roller gap and the guide throat are almost inaccessible to the human eye.  
       SUMMARY OF THE INVENTION  
       [0005]     This invention makes use of cordless video camera mounted on a special base which is so shaped as to be received for mounting on the mill bed in the same manner and in the same place as the guide assembly which is usually mounted in the mill. The camera itself is completely self contained and contains its own power supply. Focal length adjustment is possible by a slide apparatus mounted in the camera which is activated from outside the camera. Illumination of critical areas of the mill is made possible by means of a plurality of infra red (IR) light sources powered by the camera battery and mounted on the camera housing. This provides IR lighting to enhance the images produced by the output video device (monitor), which might otherwise lack clarity due to the low levels of lighting.  
         [0006]     The monitor provides the user with a video display of the image gathered by the camera as well as a preprogrammed display of an image previously selected and stored in circuitry in the monitor. The monitor is provided with circuitry and software so that the preprogrammed image may be superimposed on the image received from the camera, so that a comparison of the two images produced in the monitor may be made.  
         [0007]     When the camera is properly set up in such a manner to view the gap between a pair of mill rolls, an image may be produced in the monitor of the actual configuration of the rolls, and their associated gap. Any offset between the rolls will become immediately apparent and the roll gap may be adjusted to any desired value by viewing the image produced in the monitor. If it is desired to check for wear on the mill is rolls, the actual image of the roll profile may be immediately compared to a superimposed preprogrammed image overlaid on the actual roll image to determine if the roll profile is satisfactory or if it is not, to exchange the rolls for a new set.  
         [0008]     To begin the alignment procedure, the alignment of the video camera of this invention must be checked to see that it is in suitable condition for alignment of the guide assembly and the rolls of the mill. To check the camera alignment the camera is mounted on a special base member which itself is mounted on the bed of a test bench.  
         [0009]     The bench is made to be an exact replica of the bed of a steel mill assembly where a guide is to be ultimately mounted on a base plate to guide the work product into the reducing rolls of the mill.  
         [0010]     The camera is mounted on the special base member of the test bench and a “test” target (the position of which is known to be at a predetermined axial position on the test bench) is mounted on the test bench bed to check the camera alignment. The camera alignment is checked by means of the image of the “test” target produced in the video monitor. The monitor may be preprogrammed with a display in the form of crosshairs to enable swift determination of the camera alignment. If the “test” target is correctly portrayed on the monitor, the camera is in correct alignment and the target may be removed from the test bench and the camera may then be used to align a guide assembly which will now be mounted on its special mounting base on the test bench. (If the camera and “test” target are not properly aligned it will be assumed that the camera has lost its alignment and must be sent to a laboratory for suitable adjustment).  
         [0011]     When it has been determined that the camera is in correct alignment with the “test bed”, the guide assembly which is to be used in the steel mill is now mounted on the bench at a second station. The camera (now in the prescribed alignment with the bench bed) is now focused on the rolls of the guide assembly. The gap profile is plainly shown on the monitor and the gap may be adjusted and precisely set using the video image provided by the monitor. When the operator is satisfied with the setting of the guide assembly, the camera and guide assembly are removed from the bench.  
         [0012]     The camera is now mounted on a saddle of the mill bed where the guide assembly is to be ultimately mounted. The camera is aimed and focused on the gap existing at the main reduction rolls. The gap existing at the main rolls may be magnified and the preprogrammed image of the roll profile may be superimposed upon the image of the rolls as seen by the camera in order for the mill operator to make a judgment comparison of roll wear. The image on the monitor will give a good indication of the setting of the main rolls, or if further adjustment of the main rolls is required. The axis of the main rolls may not be coplanar and adjustment of the main rolls may have to be undertaken. The image produced by the monitor is a convenience for mill roll adjustment.  
         [0013]     At the same time the monitor may show that although the axis and the roll profile of the main rolls is satisfactory, the axis of the camera does not appear to be aligned with the axis of the main reducing rolls (i.e. the mill axis). If this situation exists the operator will instantly know that the saddle on which the camera is mounted is requires adjustment. This saddle is provided with a lateral adjustment to permit the camera to be laterally shifted (yaw axis) until it is in perfect alignment with the axis of the mill.  
         [0014]     When the camera axis and the mill axis are coincident as seen on the monitor, the camera may be removed from the saddle and the previously aligned guide assembly is mounted on the saddle in place of the camera. Because of the previous calibration of the guide achieved on the “bench”, it will be found that the guide is now in perfect alignment with the mill axis. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]      FIG. 1  is a plan view of the test bench assembly of this invention.  
         [0016]      FIG. 2  is an elevational view of the test bench assembly of  FIG. 1 .  
         [0017]      FIG. 3  is a perspective view of the test bench assembly of  FIGS. 1 and 2 .  
         [0018]      FIG. 4  is a perspective view of a display device.  
         [0019]      FIG. 5  is a perspective view of camera  16 .  
         [0020]      FIG. 6  is an exploded perspective view of camera  16 .  
         [0021]      FIG. 7  is an elevational sectional view of camera  16 .  
         [0022]      FIG. 8  is a schematic illustration of camera  16 .  
         [0023]      FIG. 9  is an exploded view of the monitor of  FIG. 4 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]     The test bench mounted apparatus  10  of this invention is shown in  FIGS. 1-3 . Bench bed  12  replicates the bed of one stage of a multi-stand reducing steel mill. The bed  12  is provided with a standard “T” groove  14  for mounting various components about to be described on the bed  12 .  
         [0025]     At one end of test bench  10  a camera  16  on is mounted on pedestal  20 . Camera  16  is housed in a robust housing  18  to protect the somewhat fragile components housed in camera  16 . Pedestal  20  has a clamping adjustment screw  22  to rigidly clamp camera  16  in place on pedestal  20  of the bench  10 . Camera  16  is also provided with a focusing adjustment provided by knob  24 .  
         [0026]     Preliminary checking of the camera  16  on pedestal  20  is provided by mounting a temporary “test” target (not shown) mounted on the bed  12 . The test target is provided with a predetermined test pattern centered on the axis of the test bench. The camera  16  is focused on the test pattern of the target to produce an image on the video monitor (shown as 50 in  FIG. 4 ). If the monitor shows the test pattern correctly portrayed on the monitor  50  the calibration of the video camera  16  on the pedestal  20  is deemed to be within tolerance and video inspection of the guide assembly may now be undertaken.  
         [0027]     The temporary “test” target is next removed from bed  12  and the camera  16  is now focused on the roller opening existing in guide assembly  30  mounted on the other pedestal  40 . The gap existing between the rolls  32  of guide assembly  30  may now be conveniently displayed on monitor  50 . The roll gap of the guide assembly  30  may be accurately adjusted by means of adjustment screw  34 , and because of the magnification provided on monitor  50  the adjustment is swift and accurate. Guide assembly  30  shown having rollers  32 , gap adjusting screw  34 , funnel entrance guide  36 , and coolant pipes and nozzles  38  is mounted on pedestal  40  on the bed  12  of bench  10 . Guide assembly  30  is held firmly in place by clamping eccentric  42 .  
         [0028]     A monitor  50  is provided to display the image as produced by camera  16 . Camera  16  and monitor  50  are both self-contained powered wireless devices utilizing rf data transmission.  
         [0029]     Camera  16  may be provided with an infra red illumination devices  28  surrounding the camera leans to improve the quality of the image displayed on monitor  50  under low level lighting conditions.  
         [0030]     The apparatus functions as follows: After adjusting the rolls  32  of the guide assembly  30  to the desired setting while being mounted on pedestal  40 , the guide assembly is now removed from pedestal  40  and camera  16  is also removed from pedestal  20  and taken to the mill where the guide assembly  30  is to be ultimately installed.  
         [0031]     Camera  16  is now installed in the mill on the saddle on which the guide assembly is to be ultimately mounted. It will usually be found that the saddle on which the camera  16  is mounted will require adjustment in the “yaw” axis. (It is to be remembered that the physical characteristics of the mill have been carefully duplicated in bench bed  12  so that the camera  16  and guide assembly  30  may be quickly and easily installed in the mill knowing that both items have been previously correctly aligned.) When the camera apparatus  16  has been installed and securely fastened to the saddle attached to the mill bed, the camera  16  is energized to produce a video image of the gap existing between the reduction rollers of the mill on monitor  50 . Camera  16  may have to be refocused to sharply define the roll gap. IR illumination may be supplied to the gap by devices  28  on camera  16 . At this time the gap image displayed on video monitor  50  may be compared with the image of the rolls and roll gap previously stored in the overlay circuitry of the monitor. The gap image may show that the planes of the rolls are not coincident; the gap between the rolls may be too large or too small; or it may be found that the camera itself may not be correctly positioned on the roll axis; or the surface profile of the rolls has deteriorated sufficiently to require roll replacement. At this time adjustments may be made to change the position of the mill rolls to correct for gap misalignment, and/or to the saddle upon which the camera is mounted to permit lateral positioning of the camera  16  on the mill axis until the correct alignment of the camera on the mill axis is achieved. At this time the position of the saddle will be locked.  
         [0032]     The camera  16  may now be now removed from the locked saddle of the mill bed and the guide assembly  30  may now be installed on the mill saddle where the camera  16  was previously mounted. Because of the previous calibration of the camera  16  and guide assembly  30  on the test bench, the guide assembly  30  will now be found to be perfectly aligned with the mill axis and the gap existing between the guide rollers  32  will be that which was set previously on bench  10 .  
         [0033]     The characteristics of the camera  16  used for the device are best described in  FIGS. 5, 6 ,  7  and  8 . Camera  16  has a housing  18  in which the CCD device  62  is housed. CCD device is held in a bezel  64  which is held in place in carrier block  66  is movable laterally with respect to lens assembly  80 . The CCD device  62  moves with bezel  64  and block  66  when control knob  24  which is mounted on shaft  70  is twisted. Shaft  70  is mounted in camera  16  in bearings  74 . End  75  of shaft  70  remote from knob  24  is threaded to engage a block  76  which moves back and forth within camera when shaft  70  is twisted. A dowel  77  is secured to block  76  to move block  66  back and forth in concert with block  76  on stationary base  78 . Movement of block  66  causes bezel  64  to move with it which in turn causes the CCD device  62  to move back and forth with respect to the lens  66 . Bezel  64  has provision for adjustably mounting the CCD device therein ( 8  set screws).  
         [0034]     The camera is supplied with a battery pack  80 , electronic circuit board and associated components  82 , a transmitter  84  and an antenna  86 . An on-off switch  88  is supplied to energize the camera  16 . Hook  90  allows the camera to be securely mounted on bench  12  or other platform such as the guide saddle in a steel mill.  
         [0035]     The camera  16  and monitor of this invention must be robust and capable of self energization to be operable at remote locations where sources of power may be difficult to locate. Both devices may be in communication by wireless electronic transmission or a cable may link the camera and monitor if desired.  
         [0036]     It is imperative that camera  16  be capable of being mounted on the bed or bench at two positions 180 degrees apart i.e. facing in opposite directions in order to provide correct alignment of reduction rolls and the guide rolls.  
         [0037]     The illumination of the critical mill parts with IR is invaluable; with the magnification it is possible to view the image on monitor  50  enlarged many times and with the added illumination provided by the IR source, the adjustment of the rollers may be extremely precise.  
         [0038]     The monitor  50  is shown in an exploded view of  FIG. 9  to illustrate some of the critical parts necessary for successful operation of this invention.  
         [0039]     Monitor  50  is shown having a case  90  in which the circuitry is mounted. This circuitry includes a receiver board  92  shown with antenna  94  attached thereto, and a video overlay board  96  for producing a preprogrammed overlay image, a battery pack  98  and an interconnect board  100 .  
         [0040]     The camera image is captured and reproduced in receiver board  92  and is displayed on a video reproduction device (not shown in  FIG. 9 ).  
         [0041]     It will be seen that this invention permits the video camera and guide apparatus to be previously aligned and set before being installed on the steel mill itself. This feature alone preserves valuable mill operating time. The alignment and profile inspection of the main rolls of the steel mill is an added bonus made possible by the magnification provided by the monitor. The instant comparison of the roll profile with a previously programmed profile of the desired roll profile is invaluable for the determination of when the steel mill rolls must be replaced.