Patent Publication Number: US-8534593-B2

Title: Method and apparatus for aligning a paper roll

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates generally to machines used for handling paperboard, which is typically used in forming corrugated paperboard. More particularly, the present invention relates to an alignment mechanism for aligning rolls of paperboard with one another. Specifically, the invention relates to a method and apparatus for aligning one edge of a given roll of paperboard with a corresponding edge of another roll of paperboard. 
     2. Background Information 
     Machines for handling rolls of paperboard are well known in the art, including corrugating machines (corrugators), splicing machines (splicers) and the like. Each of these machines handles two or more rolls of paperboard such that the web of paperboard from one roll is ultimately combined with the web from one or more other rolls of paperboard. For instance, corrugators combine a corrugated medium with a flat web of paperboard to form corrugated paperboard. Splicers splice the trailing end of the web of one roll of paperboard with the leading end of the web of another roll of paperboard in order to create a continuous web formed from the two rolls. In these cases and in other instances, it is necessary to suitably align the rolls of paperboard with one another. Improper alignment ultimately results in a paperboard product which does not have clean or sharp edges and thus must typically be trimmed in order to provide such edges. This is a very common problem in the art inasmuch as the actual width of a given roll of paperboard is often slightly different than the width ordered by the customer, typically by ⅛ or ¼ inch or the like. Although known machines typically align the paperboard rolls with one another generally, they nonetheless align them in such a manner that the left and right edges of the rolls are slightly offset relative to one another such that both the left and right edges ultimately need to be trimmed. Thus, it would be desirable to have an alignment mechanism for aligning, for example, the left edges of the rolls in order to eliminate the need for subsequent trimming along the left edges. The present invention addresses this need in the art. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a method comprising the steps of: providing a paperboard handling machine comprising a frame and a roll support assembly having left and right roll support arm assemblies which are movably mounted on the frame; mounting a first paperboard roll having left and right ends on the roll support assembly between the left and right arm assemblies; measuring with a first distance sensor a first axial distance from a first reference point to one of (a) the left end of the roll, and (b) a second reference point on the left arm assembly; calculating with a logic circuit a first axial position of the roll based on the first axial distance; comparing the calculated first axial position with a predetermined correct axial position; and if the first and correct axial positions are different from one another, adjusting the roll axially while mounted on the roll support assembly to move the roll from the first axial position to the correct axial position. 
     The present invention also provides a method comprising the steps of: providing a paperboard handling machine comprising a frame and a roll support assembly having left and right roll support arm assemblies which are movably mounted on the frame; mounting a first paperboard roll having left and right ends on the roll support assembly between the left and right arm assemblies; ascertaining a first value representing an ordered axial width of the roll; 
     measuring a first axial distance from a first reference point to a second reference point, wherein the first reference point is to the left of the left end of the roll and the second reference point is to the right of the left end of the roll; determining a second axial distance from the first reference point to the left end of the roll; calculating a calculated value including subtracting the second axial distance from the first axial distance; and moving the roll axially while mounted on the roll support assembly to a position at which the calculated value equals the first value. 
     The present invention further provides a paperboard handling machine configured for handling a paperboard roll having left and right ends, the machine comprising: a frame; left and right axially spaced roll support arm assemblies mounted on and axially adjustable relative to the frame; a roll-receiving space which is defined between the left and right arm assemblies and comprises a left side adjacent the left arm assembly and a right side adjacent the right arm assembly; the space adapted to receive therein the paperboard roll with the left and right ends respectively adjacent the left and right sides of the space; and a first distance sensor configured to measure a first axial distance from a first reference point to one of (a) the left side of the roll-receiving space, and (b) a reference point on the left arm assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       A preferred embodiment of the invention, illustrated of the best mode in which Applicant contemplates applying the principles, is set forth in the following description and is shown in the drawings and is particularly and distinctly pointed out and set forth in the appended claims. 
         FIG. 1  is a side elevational view of the paperboard handling machine of the present invention showing one of the rolls of paperboard mounted thereon. 
         FIG. 2  is an end elevational view of the lower portion of the machine. 
         FIG. 3  is a top plan view of the machine showing one roll of paperboard mounted on the machine and a second roll of paperboard being positioned for mounting on the machine. 
         FIG. 4  is a sectional view taken on line  4 - 4  of  FIG. 3 . 
         FIG. 5  is a sectional view taken on line  5 - 5  of  FIG. 3 . 
         FIG. 6  is a top plan view of the machine showing the second roll of paperboard mounted on the machine out of alignment with the first roll. 
         FIG. 7  is a top plan view of the machine showing the machine having moved the second roll into alignment with the first roll. 
     
    
    
     Similar numbers refer to similar parts throughout the drawings. 
     DETAILED DESCRIPTION OF THE INVENTION 
     The paperboard handling machine of the present invention is shown generally at one in  FIG. 1 . Machine  1  is configured for handling and aligning first and second rolls  2  and  4  of paperboard. Machine  1  may also be configured to handle and align additional rolls of paperboard using the alignment mechanism described further below. 
     Machine  1  includes a rigid stationary frame  6  which typically includes several rigid uprights which support longitudinal rails with rigid horizontal beams extending therebetween to form a rigid structure on which the various moving parts of the machine are mounted. Machine  1  has upstream and downstream ends  8  and  10  defining therebetween a longitudinal direction and more particularly a downstream direction (arrow A in  FIG. 1 ) in which the webs of paperboard ultimately travel after unwound from rolls  2  and  4 . Machine  1  has left and right sides  12  and  14  ( FIGS. 2 ,  3 ) defining therebetween an axial direction. Machine  1  includes first and second roll loading or support assemblies  16  and  18  each including left and right roll support arm assemblies which respectively include left and right roll loading or support arms  20  and  22  which are axially spaced from one another. Each arm  20  and  22  adjacent one end is pivotally mounted on frame  6  at a respective pivot  24  whereby the arms of each assembly  16  and  18  are respectively pivotally mounted about horizontal parallel axially extending axes passing through pivots  24 . More particularly, a pair of parallel axially elongated support shafts  26  are pivotally mounted on frame  6  about the axes of pivots  24  with the corresponding set of arms  20  and  22  mounted on and extending radially outwardly from the corresponding shaft  26  in order to rotate therewith. Axially elongated keyways  28  are formed in each support shaft  26  for receiving therein respective keys  30  of arms  20  and  22  whereby arms  20  and  22  are movable in the axial direction relative to shaft  26  with keys  30  sliding within the respective keyways  28 . Mounted adjacent the terminal outer end of each arm  20  and  22  are respective chucks  32  extending outwardly from a respective annular collar  34  having an annular generally vertical stop or stop surface  36 . Each chuck  32  is rotably mounted about a pivot or pivot axis  38  which is horizontal and axially extending whereby axes  38  are parallel to axes  24 . The rotatable nature of chucks  32  thus allows for a given roll  2  or  4  when mounted thereon to rotate about the corresponding axis  38  to allow the web to unwind from the roll of paperboard. A brake  40  is also mounted adjacent the outer end of each arm  20  and  22  to provide braking ability to slow or stop the rotation of chucks  32  of the corresponding roll mounted thereon. 
     Actuators  42  ( FIG. 4 ) are provided for driving the pivotal movement of arms  20  and  22  respectively about axes  24  in order to raise and lower the outer ends of set arms and rolls  2  or  4  therewith. In the exemplary embodiment, each actuator  42  is in the form of a piston-cylinder combination wherein the cylinder is pivotally mounted on frame  6  and the cylinder is pivotally mounted on a respective one of arms  20  and  22  whereby extension and retraction of the piston (arrows B) drives the pivotal movement of the respective arm. In the exemplary embodiment, a hydraulic system  44  including a hydraulic pump is provided to power actuators  42 . A control unit or controller  46  is provided to allow the operator of machine  1  to control the various operations thereof and thus typically includes various control buttons, knobs, switches and the like. Controller  46  includes a suitable computer or logic circuits for making calculations described further below. A display monitor or screen  7  is in electrical communication with controller  46 . In addition to lift actuators  42 , clamping actuators  48  ( FIG. 3 ) are mounted on frame  6  to drive the axial movement of the left and right arms  20  and  22  relative to support shaft  26 . In the exemplary embodiment, actuators  48  are in the form of piston-cylinder combinations and are hydraulically operated. Thus, the hydraulic system  44  is in fluid communication with actuators  42  and  48  to provide hydraulic fluid thereto. 
     In accordance with the invention, machine  1  includes an alignment mechanism or assembly which includes first and second distance sensors  50  and  52  which are in electrical communication with controller  46  via respective electrical wires  54 . Sensors  50  and  52  are parts of measurement devices for measuring axial distance as discussed further below. Sensors  50  and  52  in the exemplary embodiment are ultrasonic sensors each of which produces an ultrasonic wave (dashed lines in  FIGS. 6 and 7 ) which reflect respectively off the left side  56  of arm  20  and left end  60  of roll  4 , thereby allowing the ultrasonic waves to determine the distance from the sensor to the respective reference point. Other suitable sensors may be used. Each sensor  50  is securely mounted on frame  6  or adjacent frame  6  so that sensor  50  is fixed relative to the frame and is configured for measuring the horizontal axial distance from a reference point such as the right side of sensor  50  to another reference point such as the left side  56  of the corresponding left arm  20 . Sensor  52  is configured to measure the horizontal axial distance from a reference point such as the right side of sensor  52  or right side  58  of left arm  20  to a reference point such as the left end  60  of the corresponding roll  2  or  4 . Each roll further has a right end  62  whereby left and right ends  60  and  62  also serve as the left and right edges of the web  64  of paperboard which unwinds from the respective roll. The reference point represented by the right side of sensor  50 , which is axially fixed with respect to frame  6 , is to the left of the left arm assembly  20 , the left end  60  of roll  4  and the various other reference points mentioned herein. The reference point on left arm assembly  20  represented by left side  56  is to the left of the reference points  58  and  60 , and is axially movable as left arm  20  moves axially although reference point  56  is axially fixed when the left arm assembly is secured against axial movement and thus fixed relative to frame  6  at a given time. Reference point  58  is similarly axially movable and may be fixed in the same manner as reference point  56 , and is to the left of reference point  60 . 
     The operation of machine  1  is now described. As shown throughout the Figures, the first roll  2  has already been mounted on first assembly  16  and aligned in the axial direction to the desired position in the same manner as will be described below with respect to second roll  4 . The lift actuator  42  associated with second assembly  18  is extended or retracted in order to pivot the arm along with its corresponding chuck  32 , collar  34  and brake  40  about pivot axis  24  to raise or lower the chucks  32  to the correct height needed for mounting roll  4  thereon. Roll  4  is then inserted (arrow C in  FIG. 3 ) into a roll receiving space  66  defined between the left and right arm assemblies of assembly  18 . This insertion of roll  4  into space  66  is done so that a central passage  68  defined by a cylindrical core  70  of roll  4  is aligned ( FIG. 6 ) with chucks  32  on either end thereof. Web  64  of paperboard is wound around core  70  to form roll  4 . Once the chucks  32  are aligned with passage  68 , actuators  48  are operated to insert chucks  32  axially into the left and right ends of passage  68  (arrows D in  FIG. 6 ) to mount roll  4  on assembly  18 . At this stage, left end  60  and right end  62  of roll  4  is typically closely adjacent or abutting the opposed stop surfaces  36  of the corresponding collars  34 . Once roll  4  is mounted in this fashion, the axial distance between arms  20  and  22  is fixed throughout the following steps of the process until it is time to remove core  70  (and roll  4  if necessary) from assembly  18 . As illustrated in  FIG. 6 , the left edge  60  of roll  4  is axially offset from the left edge  60  of roll  2  such that the left edges  60  are not axially aligned with one another. Thus, actuators  48  are operated to move the left and right arm assemblies of assembly  18  axially in a coordinated fashion at the same rate to the right (arrow E of  FIG. 7 ) so that left edges  60  are aligned with one another as clarified by the dot-dashed line F. Although the left edges  60  are axially aligned with one another,  FIG. 7  also illustrates that the right edges  62  of rolls  2  and  4  are not aligned with one another inasmuch as the axial width of the rolls  2  and  4  in the exemplary embodiment are different. More particularly, roll  4  has an axial width A 1  defined between its left and right end  60  and  62  which is less than the axial width A 2  of roll  2  defined between its left and right end  60  and  62 . The difference between axial width A 1  and axial width A 2  is typically no more than about one ½ inch although this may vary, and these widths may be equal. 
     The alignment mechanism of the present invention is configured to ensure that the left edges  60  are aligned with one another. The use of the alignment mechanism is discussed primarily with reference to  FIG. 6 . Sensor  50  is positioned so that its right edge is an axial distance W from a reference point which is axially between the left and right arm assemblies and the left and right ends  60  and  62  of roll  4 . This reference point is preferably a center line CL of machine  1  which is generally midway between left and right sides  12  and  14 . Reference point CL is axially fixed relative to frame  6 , is to the right of all the other reference points mentioned herein, is to the right of the left arm assembly and left end  60 , and is to the left of the right arm assembly and right end  62 . Width W is a fixed distance which is measured with a suitable measuring device. Sensor  50  is configured to measure an axial distance X defined between the right side of sensor  50  and left side  56  of left arm  20 . Axial distance X varies depending on the axial position of arm  20 . Left and right sides  56  and  58  define therebetween an axial width Y of arm  20 , which is a fixed distance measured by a suitable measuring device. Sensor  52  is configured to measure an axial distance Z defined between the right side of sensor  52  or right side  58  of arm  20  and the left end  60  of roll  4 . Distance Z will vary depending on the axial position of roll  4  relative to arm  20  and sensor  52 . In many cases, distance Z will be substantially the same as the distance between the right side of sensor  52  or right side  58  and the right stop surface  36  of collar  34  mounted on left arm  20  inasmuch as left end  60  of roll  4  may abut said surface  36 . However, left end  60  may be axially spaced from surface  36  such that distance Z is different than the axial distance between right side  58  or the right side of sensor  52  and surface  36 . In any case, controller  46  uses as inputs the axial distances W, X, Y and Z as respective measured values in order to calculate the axial position of left edge  60  so that it may be properly aligned depending on the width of a given roll. In the paperboard industry, one of the standard axial roll widths is 110 inches and another standard width is 98 inches. More particularly, each of these standard widths represents an ordered width which has been ordered by the operator or customer using machine  1 . However, as previously noted, the actual width is often slightly greater than the ordered width by a ⅛ inch, ¼ inch or so forth. 
     In the exemplary embodiment, in order to determine the axial position of roll  4 , controller  46  calculates the ordered axial width of roll  4  based on axial distances W, X, Y and Z. More particularly, the ordered axial width of roll  4 , which is equal to or slightly less than the actual axial width A 1 , is two times the difference between axial distance W and the sum of axial distances X, Y and Z. Thus, controller  46  includes a computer program which utilizes this mathematical formula to calculate the ordered axial width of roll  4  and display the value of this axial width on screen  7 , as shown in  FIG. 7 . Although  FIG. 7  shows the calculated value of 110 inches corresponding to the ordered axial width of roll  4  when it is aligned properly relative to frame  6  so that the left ends  60  of rolls  2  and  4  are axially aligned, the calculated value will obviously be different when the axial position of roll  4  is not at the aligned position. Thus, the value which would be displayed on screen  7  when roll  4  is in the position shown in  FIG. 6  would be different than the ordered axial width of roll  4 . In the exemplary embodiment, the operator of machine  1  thus loads roll  4  on support assembly  18  as previously described and then watches or views screen  7  to see if the value displayed thereon as calculated by controller  46  matches the ordered axial width which the operator knows in advance. Thus, in the example shown, the roll  4  is moved axially to the right from the position of  FIG. 6  to the position of  FIG. 7  while mounted on support assembly  18  while controller  46  performs real time calculations based on the various inputs and displays the value in real time on screen  7  associated with any given axial position of roll  4 . When the value displayed on screen  7  equals the known or predetermined ordered axial width of roll  4 , the operator stops the axial movement of support assembly  18  and roll  4  at the correct axial position at which the roll is properly aligned and secures support assembly  18  against axial movement in order to ensure that the rolls  2  and  4  remain properly aligned during the subsequent operation of machine  1 . 
     Alternately, controller  46  may be configured to make the comparison between the measured axial width of roll  4 , and thus its axial position, and the ordered axial width and thus the correct aligned position. More particularly, the ordered axial width value may be input into controller  46  whereby the logic circuits of controller  46  compare this value with the measured axial width of roll  4  so that when they match, controller  46  controls actuators  48  to automatically stop the axial movement of assembly  18  and roll  4  at the correct or aligned axial position. 
     As previously noted, reference point CL is preferably a center line of the machine, which makes the mathematical formula noted above apply equally to any given ordered axial width. Thus, the alignment mechanism may be used as well with the 98 inch roll or any other axial width of the roll to properly calculate the axial position of the roll. 
     In the foregoing description, certain terms have been used for brevity, clearness, and understanding. No unnecessary limitations are to be implied therefrom beyond the requirement of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed. 
     Moreover, the description and illustration of the invention is an example and the invention is not limited to the exact details shown or described.