Abstract:
An automated roll handling system includes a cart with an integrated vertical spindle and a plurality of wheels on bottom frame of the cart. A trio of cart locating pads is situated on the bottom frame of the cart, and a cart centering post is situated on the bottom frame of the cart and used in combination with the trio of cart locating pads to locate the spindle in space to a predetermined positioning tolerance that allows for control of five degrees of freedom. A roll transfer system is also provided including a pivot arm, a system frame, a vacuum arm, a plurality of vacuum suction cups affixed to the vacuum arm for holding a sidewall of a stock roll, and a cart locator system on the bottom of the system frame for precise positioning of the cart.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention relates generally to the field of roll handling, and in particular to a system for accurately positioning a roll handling cart, and transferring stock rolls of web to and from a cart.  
       BACKGROUND OF THE INVENTION  
       [0002]     In many kinds of roll handling carts, such as those described in U.S. Pat. Nos. 5,674,040 and 5,934,604, stock rolls are supported on their outside convolution of web, which can damage several of the outer web convolutions of the stock roll. To eliminate the damage to the web, stock rolls are often horizontally supported by a cantilevered support spindle, which supports a stack of stock rolls by the inner diameter of their cores. U.S. Pat. No. 5,165,767 and European Patent No. EP 1 211 554 A1 illustrate such carts. However, in some cases, because the inner diameter of the core is not sufficiently large enough, and the weight of the stack of stock rolls is too great, a horizontal cantilevered support is not practical.  
         [0003]     In U.S. Patent Application Publication U.S. 2002/0054811, an apparatus uses an expansion assembly incorporated within a support mandrel to hold the inner bore of the stock roll&#39;s core. This method can be problematic when transferring some configurations of stock rolls in the vertical orientation, because the stock rolls may have been loosely wound, or the weight of the wound web will pull off its core. Also, when loading or unloading a machine process spindle with a stock roll of web, the stock roll core bore needs to be open and accessible. Sometimes the expansion force against the core bore is too great and damages the core. Therefore, the apparatus described in U.S. Patent Application Publication U.S. 2002/0054811 has limitations, and is not practical for use with large rolls of motion picture film, for example.  
         [0004]     To automatically remove stock rolls from a cart and transfer the stock rolls to an adjacent machine process can require a means to accurately locate the stack of stock rolls which reside on the cart, and a means to accurately position the cart. In many kinds of carts, such as those disclosed in European Patent No. EP 1 211 554 A1, the final located position of the cart requires the wheels, which remain in contact with the floor or a platform surface, to accurately position the elevation of the cart. This can be problematic, because the cart&#39;s wheels are subject to wear and can collect dirt. Therefore, there is a need to accurately locate a cart without the critical setup or alignment of its wheels.  
         [0005]     There is a need for automatic roll handling systems which can “accurately” load or unload stock rolls of web, such as motion picture film, to or from a machine which processes, or performs other operations upon this web. There is also a need to automatically handle a significant number of stock rolls to greatly reduce the operational labor requirements such as manually lifting and transferring stock rolls. There is also a need for an automatic roll handling system, which handles the stock rolls in a safe manner to minimize the creation of handling defects. There is also a need for an automatic roll handling system which can work effectively in a dark room environment, which is required for handling light sensitive materials. Finally, there is need for a simple and low cost system, which can meet these requirements  
       SUMMARY OF THE INVENTION  
       [0006]     The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, an automated roll handling system is provided, comprising a cart with an integrated vertical spindle comprising, and a plurality of wheels on bottom frame of the cart. A trio of cart locating pads situated on the bottom frame of the cart, and a cart centering post situated on the bottom frame of the cart and used in combination with the trio of cart locating pads to locate the spindle in space to a predetermined positioning tolerance that allows for control of five degrees of freedom is provided. A roll transfer system, is also provided comprising a pivot arm, a system frame for supporting the pivot arm, a vacuum arm that is capable of sliding within the pivot arm, a plurality of vacuum suction cups affixed to the vacuum arm for holding a sidewall of a stock roll, and a cart locator system on the bottom of the system frame for precise positioning of the cart using the combination of the trio of cart locating pads and the cart centering post.  
       ADVANTAGEOUS EFFECT OF THE INVENTION  
       [0007]     The present invention provides a means of transferring a stock roll of web without contacting or supporting the outer convolutions of web, and thus eliminates the risk of damaging the outer convolutions of web. The present invention also provides a means of stacking stock rolls on their sidewalls, in a cart, and precisely locating the stack of stock rolls via their cores&#39; inner diameters to protect and accurately position the stock rolls.  
         [0008]     The present invention provides a means to accurately locate the cart without the use of its wheels. A simple and accurate system for loading and unloading stock rolls to and from a cart and onto and off of a machine is also provided.  
         [0009]     These and other aspects, features, and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of the cart.  
         [0011]      FIG. 2  is a side cross sectional view of the cart.  
         [0012]      FIG. 3  is a perspective view of the bottom of the cart.  
         [0013]      FIG. 4  is a perspective view of the top of the cart.  
         [0014]      FIG. 5  is top perspective view of the roll transfer system.  
         [0015]      FIG. 6  is a perspective view of the pivot arm and vacuum arm assemblage.  
         [0016]      FIG. 7  is a side view of the pivot arm and vacuum arm assemblage.  
         [0017]      FIG. 8  is a back view of the pivot arm and vacuum arm assemblage.  
         [0018]      FIG. 9  is a side view of the cart docked in the roll transfer system, adjacent to a processing machine.  
         [0019]      FIG. 10  is another side view of the cart docked in the roll transfer system adjacent to a machine.  
         [0020]      FIG. 11  is a perspective view of the datum locating features of the cart. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0021]     Based on the prevailing needs and inadequate solutions mentioned above, it is desirable in this case to support the stack of rolls on their sides to prevent damage to the stock rolls outer convolutions, and also provide a means to accurately locate the stack of stock rolls via their cores inside diameters, by use of a vertical spindle integrated into the cart. Also, it is desirable to accurately locate a cart and the stack of stock rolls it carries independent of the cart&#39;s wheels.  
         [0022]     Referring to  FIG. 1 , a stock roll transfer system  1  incorporates the use of a cart  2 , which holds a stock roll stack  11 . The cart  2  can be manually positioned by an operator into a docking position of the stock roll transfer system  1 . The cart  2  could also be automatically delivered by any number of means that are not specifically illustrated, and positioned into a docking position of the stock roll transfer system  1 .  
         [0000]     Cart  
         [0023]     The cart  2 , illustrated in  FIGS. 2, 3  and  4 , includes a cart frame  5 , supported by caster wheels  6 . There is a raised section of the cart frame  5  that supports a handle  29 , for manually pushing and positioning the cart. The cart spindle  7  supported on top of the frame  5  is in the vertical orientation, and the three cart locating pads  8 A- 8 C and the bottom cart centering post  12  are fixed to the bottom of the cart frame  5 . The cart spindle  7  is very accurately located perpendicular to the cart reference plane  30 , which is defined by the three cart locating pads  8 A- 8 C (shown in  FIG. 3 ), which are within 0.005 inches, for example. The cart spindle  7  is approximately the length of the height of the stock roll stack  11 , as seen in the side cross sectional view in  FIG. 2 , so it can maintain positional control of each stock roll  9  on the cart  2 . The cart centering post  12  can be constructed at the bottom end of the cart spindle  7 , or the cart centering post  7  can be another component, which is in accurate axial alignment to the cart spindle  7 . The cart spindle  7  prevents movement of the stock roll stack  11  during transit. Also, the cart spindle  7  provides a locator for loading the stock roll cart  2  manually or automatically.  
         [0000]     Stock Roll Transfer System  
         [0024]     The stock roll transfer system  1 , illustrated in  FIGS. 5-10 , is made of a handling system frame  13 , which pivotally supports a pivot arm  20 . A rotary actuator  19  drives the pivot arm  20  in clockwise (CW) and counter-clockwise (CCW) directions. The rotary actuator can be a commercially available pneumatic or hydraulic device, or it can be constructed from an electric rotary drive. The pivot arm  20  rotation is limited by the pivot arm horizontal stop  24  and pivot arm vertical stop  25 , which are fixed to the handling system frame  13 . These stops accurately locate the rotational end positions of the pivot arm  20  at the load and unload positions.  
         [0025]     Inside the tube structure of pivot arm  20 , seen in  FIGS. 6, 7 , and  8  (which is removed from the stock roll transfer system  1  for clarity), a vacuum arm  21  is mounted with a slide  22 , which has its linear motion along the direction of the length of the pivot arm  20 . Also, inside this tube structure is a rodless cylinder  23 , which is also commercially available, which actuates the vacuum arm  21  its extended length. Vacuum arm  21  is made of a long tube structure, which has the slide  22  rail section attached inside its inner wall. Vacuum arm  21  has a head end that supports a plurality of vacuum suction cups  26  (four are illustrated for exemplary purposes). When the vacuum arm  21  is extended to move the core  10  of web stock roll  9 , over the machine spindle  4 , the extended position is controlled by stop cylinder  28 . When stop cylinder  28  is extended, it stops the motion of the rodless cylinder  23  to an intermediate position. It is preferable to stop the vacuum arm  21  in an intermediate position, verses stopping this motion with the stock roll  9  or its core  10  against a stop feature, which may cause damage to the stock roll  9 .  
         [0026]     Vacuum suction cups  26  are designed to support a single stock roll of web by holding the web&#39;s sidewall with sufficient vacuum pressure. The vacuum arm&#39;s  21  tube inner opening is designed to clear the diameter of the cart spindle  7  when acquiring a stock roll  9 .  
         [0027]     The lower section of the stock roll transfer system  1 , as shown in  FIG. 5 , accurately locates the cart and the stock roll stack. There are caster slots  18  in the bottom support plate  27 , which provide clearance for the cart caster wheels  6  shown in  FIG. 9 . The caster slots  18  also limit the rotational movement of the cart, by restricting the cart wheels&#39;  6  motion, which ensures that the cart&#39;s cart locating pads  8 A- 8 C remain in alignment with the three cart lifting devices  14 A,  14 B,  14 C. The cart locator  15  positions the cart centering post  12 . The cart locator latch  16 , which is pivotally mounted to the cart locator  15 , pushes the cart centering post  12  accurately into the cart locator  15 , accurately controlling two degrees of freedom. The cart locator latch  16  is actuated by a locator latch cylinder  17 , which is pivotally mounted to both the cart latch  16  and the support plate  27 . The three cart lifting devices  14 A,  14 B and  14 C, slightly lift the cart wheels  6  off the floor to an accurate locating plane defined by the extended position of the three cart lifting devices, and thereby accurately controlling three additional degrees of freedom. The five degrees of freedom of the cart  2 , accurately positioned by the stock roll transfer system  1 , are illustrated with arrows and labeled X, Y and Z in  FIG. 11 . The cart lifting devices  14 A,  14 B and  14 C can be constructed from commercially available pneumatic or hydraulic cylinders, or from electrically driven linear actuators. Once the cart  2  is accurately positioned, loading or unloading of the cart  2  by the stock roll transfer system  1  can be performed.  
         [0000]     Controls  
         [0028]     The stock roll transfer system  1  uses a vacuum supply, (not shown), for the evacuation of air to the vacuum suction cups  26 , which could be supplied from a factory vacuum, a vacuum pump, a compressed air vacuum generator, or other means. The rodless cylinder  23  can be any pneumatic or hydraulic device, which is commercially available, or it could be configured as linear electrical drive. The control for these devices can be performed by an independent controller or by the one used by the adjacent machine  3 .  
         [0000]     Basic Control Functions:  
         [0029]     Head vacuum on/off  
         [0030]     Pivot arm rotation CW/CCW  
         [0031]     Vacuum arm extension in/out  
         [0032]     Stop cylinder in/out  
         [0033]     Cart latch closed/open  
         [0034]     Cart lifting devices up/down  
         [0035]     The exemplary steps of operation for loading stock rolls  9  onto the machine  3  are as follows:  
         [0036]     (1) The cart  2  is manually pushed into the stock roll transfer system  1  docking location, as initially illustrated in  FIG. 1 . The cart center post  12 , seen in  FIGS. 2 and 3 , stops against the cart locator  15 , seen in  FIG. 5 . The docking position of the cart  2  in the stock roll transfer system  1  can be seen in  FIG. 9 .  
         [0037]     (2) The locator latch cylinder  17  is energized and subsequently actuates the cart locator latch  16  against the cart center post  12  accurately and securely against the locator  15 . This actuation accurately locates the X and Y positions of the cart  2 , as depicted in  FIG. 11 .  
         [0038]     (3) The three cart lifting devices  14  A-C are actuated to engage with the three cart locating pads  8  A- 8 C, and lift the cart  2  slightly off the floor, so the cart wheels  6  no longer have positional control of the cart  2 . Now the cart  2  has been accurately positioned in preparation for the stock roll unload steps, seen in  FIG. 9 . The actuation of three lifting devices  14  A-C accurately locates the three Z positions of the three associated cart lifting pads  8  A-C, as depicted in  FIG. 11 .  
         [0039]     (4) The vacuum arm  21 , which is initially in its vertical position and fully retracted, also shown in  FIG. 9 , is actuated downwards by a controlled force of the rodless cylinder  23 . The vacuum suction cups  26 , attached to the vacuum arm  21 , come in contact with the top-most stock roll  9  of the stock roll stack  11  and stops the motion. Immediately the vacuum suction cups  26 , which are under vacuum pressure hold the sidewall of the top-most stock roll  9 , with more than sufficient force to lift the weight of the top-most stock roll  9 .  
         [0040]     (5) The vacuum arm  21  is now fully retracted by the actuation of the rodless cylinder  23 , as seen in  FIG. 9 .  
         [0041]     (6) The rotary actuator  19  is actuated to rotate the pivot arm  20  in the horizontal position, where it comes to rest against pivot arm horizontal stop  24 , as seen in  FIG. 10 .  
         [0042]     (7) The stop cylinder  28  is actuated to limit the travel of the rodless cylinder  23  forward stroke.  
         [0043]     (8) The vacuum arm  21  is extended outward via the actuation of the rodless cylinder  23 , until it is stopped by the stop cylinder  28 . This motion delivers the stock roll  9  accurately over the machine spindle  4 , which is a collapse state, as seen in  FIG. 10 .  
         [0044]     (9) The machine spindle  4  is activated to grasp the inner diameter of core  10 .  
         [0045]     (10) The vacuum cups  26  vacuum is de-energized to release hold of the stock roll  9 .  
         [0046]     (11) The vacuum arm  21  is fully retracted via the actuation of the rodless cylinder  23 .  
         [0047]     (12) The pivot arm  20  is rotated via the rotary actuator  19 , until the pivot arm  20  comes to rest against pivot arm vertical stop  25 , seen in  FIG. 1 .  
         [0048]     (13) The vacuum suction cups  26  vacuum pressure is energized when the next automatic command is given to acquire and load another stock roll  9  onto the machine spindle  4 .  
         [0000]     Although the steps to unload a stock roll  9  from a machine are not described, it is obvious to those ordinarily skilled in the art that reversing the process steps provides this capability.  
         [0049]     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.  
       Parts List  
       [0000]    
       
           1  Roll transfer system  
           2  Cart  
           3  Machine  
           4  Machine spindle  
           5  Cart frame  
           6  Cart wheels  
           7  Cart spindle  
           8 A- 8 C Cart locating pads  
           9  Stock roll  
           10  Core  
           11  Stock roll stack  
           12  Cart centering post  
           13  Handling system frame  
           14 A-C Cart lifting devices  
           15  Cart locator  
           16  Cart locator latch  
           17  Locator latch cylinder  
           18  Caster slots  
           19  Rotary actuator  
           20  Pivot arm  
           21  Vacuum arm  
           22  Slide  
           23  Rodless cylinder  
           24  Pivot arm horizontal stop  
           25  Pivot arm vertical stop  
           26  Vacuum suction cups  
           27  Bottom support plate  
           28  Stop cylinder  
           29  Handle  
           30  Cart reference plane