Abstract:
A web press rotary equipment protection device is disclosed. The device includes a roller that is slotted to receive a media used as part of a rotary process. The device remains in a stationary position, allowing the media to pass through the slot of the roller, until a break in the medium occurs. Upon such an occurrence, the roller rotates, thereby engaging the media and allowing the media to wrap around the roller rather than being drawn back into the rotary device of the rotary process. The device is useful in any rotary-type process, such as printing, converting plastic and textile industries where it is desirable to have a medium to be wrapped rather than be withdrawn back into the source of the media roll or dispensed directly onto a floor after a medium break. The device is useful to prevent damage to rotary systems resulting from the media being pulled back into the rotary system.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    The present application claims the benefit of U.S. Provisional Application No. 60/331,836 filed Nov. 20, 2001, which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates generally to protection devices for web press rotary equipment. More specifically, the present invention relates to a system and methodology for preventing wrap ups and damage to web press rotary equipment as a result of web breaks in the medium used in web printing or other rotary press.  
           [0003]    In industrial process applications, particularly in automatic processes on web printing presses, maintaining continuity of the web is critical to proper operation of the web press rotary equipment. It is common for various web materials or medium (e.g., paper, textile, plastic, etc.) to be unwound and fed through a rotary process as part of an industrial operation (e.g., printing press, die cutter, perforating unit, gluing unit, coating unit, etc.). In some applications, a web printing press will utilize a rotary printing press that uses a continuous roll of paper that travels through the press.  
           [0004]    In many of these industrial applications, the medium can tend to break when exiting from the rotary application due to, for example, a defect in the medium itself, or fatigue in the medium which may be caused by the industrial process. As press speeds increase, the need to protect the print unit from a potentially damaging web break also increases.  
           [0005]    Breaks in the web medium can result from bad paper splices (splices are used when one roll is depleted and a new roll is started). Also, ineffective joints formed between the old paper rolls and new paper rolls, defective paper, and slime hole defects (a natural defect in the paper during the paper making process which leaves a hole in the paper which weakens the paper as it goes through the press) all contribute to breakage in the web medium.  
           [0006]    Referring to FIG. 1, a schematic illustration of a web break is shown in a prior art rotary process without use of a web press rotary equipment protection device. In this figure, after a web medium  1  passes through a rotary process  2 , and enters a dryer device  3 , a web break  4  occurs. Therefore the continuity in the web medium  1  is disrupted.  
           [0007]    As a result of the medium breaking after the rotary process, the medium will be pulled back into the last cylinders from which the web medium exited following the rotary process. This “pull back” causes “wrap ups” of the medium onto the rotary cylinders within the rotary process equipment. The result of wrap ups may include, among other things, damage to the rotary cylinder and cylinder journals. Additionally, other damage can be caused by the medium continuing to build up on the cylinders until the process is stopped by an operator or detection device. Further, damage that is caused to the rotary printing unit from a web wrap up after a web break can create the following problems for the printer: excessive down time caused by attempts to remove the paper from the cylinder; damage to rubber blankets associated with the printing apparatus; cylinder slippage resulting from printing cylinders that go out of time synchronization in relationship to other cylinders in the unit; and finally, bending of the printing cylinder journals. The removal and repair of cylinders increases down-time, labor costs, part costs and lost production.  
           [0008]    [0008]FIG. 2 shows a schematic illustration of a resulting wrap up from the web break of FIG. 1. Web medium  1  following a break is shown wrapping up around a cylinder  5  of rotary process  2 . The wrap up occurs because of the continued rotation of cylinder  5  in a direction indicated by arrow  6  even after the web medium  1  has been broken.  
           [0009]    Also, a web press printing system will often include, in addition to one or more rotary printing operations, a final drying operation that dries the paper or other web medium that is fed through the web press. Web breaks that occur in or around the dryer can result in similar problems caused by the post-break medium entering the drying area.  
           [0010]    In general, prior solutions included rollers that were constantly in motion that pushed the web onto a roller when a web break was detected.  
           [0011]    In the past, high-speed web (paper) detection systems have been used to detect web breaks. These systems would monitor the status of the paper going through the press and determining if the paper was in tact or if it had broken. As a result of the web break being detected, the web detection system would send a signal to shut down the press and also to activate a severing device to cut the paper in a strategic location. These systems had limited success to catch each web break in time, particularly as press speeds increased.  
           [0012]    Other systems, upon a break in the web, pulled paper out of the rotary application by two pinch rollers that would push the paper onto the floor causing clutter, and potentially unsafe conditions.  
           [0013]    Therefore, it would be desirable to be able to, following a break in the web medium, prevent the web medium from being pulled back into a rotary process, and prevent “wrap ups” of the web medium onto the cylinders and journals used in the web process. Also, it would be desirable to retrieve the broken web medium from a dryer unit in the printing process.  
         SUMMARY OF THE INVENTION  
         [0014]    Disclosed herein is a protection device for web press rotary equipment. In one aspect of the invention, a web press rotary equipment protection device for use with a rotary system and a web medium is disclosed, the device comprising: a roller having a web medium passage slot, the roller capable of receiving the web medium through the medium passage slot; wherein upon a break in the web medium, the roller rotates and engages the web medium in the medium passage slot such that the web medium wraps around the roller, thereby preventing the web medium from being pulled back into the rotary system.  
           [0015]    In another aspect, a method of protecting a rotary web press disclosed, the method comprising: providing a roller having a web medium passage slot for receiving a web medium therethrough from the rotary web press; passing the web medium through the web medium passage slot of the roller.  
           [0016]    Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The drawings illustrate several embodiments presently contemplated for carrying out the invention.  
         [0018]    In the drawings:  
         [0019]    [0019]FIG. 1 is a schematic illustration of a web break in a prior art rotary process without use of a web press rotary equipment protection device;  
         [0020]    [0020]FIG. 2 is a schematic illustration showing a resulting wrap up from the web break of FIG. 1;  
         [0021]    [0021]FIG. 3 is a schematic illustration of a web break in a rotary process using the web press rotary equipment protection device according to one aspect of the present invention;  
         [0022]    [0022]FIG. 4 is a schematic illustration showing the web press rotary equipment protection device engaged according to one aspect of the present invention;  
         [0023]    [0023]FIG. 5 is a schematic illustration of web press rotary equipment protection system according to one aspect of the present invention;  
         [0024]    [0024]FIG. 6 is a front view of the web press rotary equipment protection device with pneumatic motor drive in accordance with one aspect of the present invention.  
         [0025]    [0025]FIG. 7 is a side view of FIG. 6;  
         [0026]    [0026]FIG. 8 a front view of the web press rotary equipment protection device with electric motor drive in accordance with one aspect of the present invention;  
         [0027]    [0027]FIG. 9 is a side view of FIG. 8; and  
         [0028]    [0028]FIG. 10 is schematic overview of the press rotary equipment protection system with pneumatic motor drive in accordance with one aspect of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0029]    Referring to FIG. 3, a schematic illustration of a web break in a rotary process using the web press rotary equipment protection device, generally identified by the numeral  10 , is shown. The device  10  is positioned between the rotary application, such as a printing press  2 , and dryer device  3 . Web medium  1  is shown fed into and through device  10 . Web medium  1  is shown breaking at location  4  within dryer  3 .  
         [0030]    Now turning to FIG. 4, a schematic illustration showing the web press rotary equipment protection device  10  in an engaged position is provided. Cylinder  12  of device  10  rotates in a direction indicated by arrow  14  to engage web medium  1  following a break, thereby tensioning medium  1  and removing them from the cylinders of rotary application  2 , as well as from the drying unit of FIG. 3.  
         [0031]    [0031]FIG. 5 is a schematic illustration of web press rotary equipment protection system according to one aspect of the present invention. The present invention may be provided as part of a new rotary press system, or alternatively, used as a retrofit to existing rotary press systems. Although the present invention is shown as used in a printing operation, it is contemplated that the present invention may be used in any industry in which protection of the rotary components is desired. These industries may include the web converting (paper making), textiles, plastics or other industries in which the rotary components used as part of printing, embossing, calendaring or extruding operations could become damaged as a result of a break in the material being used in the process  
         [0032]    Rotary process  2  generally includes rotating cylinders  6  and  7 , rotating in opposite directions in a conventional manner to move a web medium  1  away from rotary cylinders  6  and  7 . Web medium  1  may include any suitable medium, including paper, plastic or textiles. Web medium  1  travels through a roller or cylinder  12  having a web medium passage slot or opening  14  that permits the web medium  1  to pass through roller  12 . During unbroken web operation, roller  12  does not rotate and utilizes toothed knife blades  16  located above and below the web medium  1  on opposite ends of roller  12  to provide support for, and if necessary cut in an emergency, web medium  1 .  
         [0033]    During operation, a detector or sensor  18  is used to monitor the continuity of web medium  1  and detect any breaks in the web medium Detector  18  may be supplied as part of a package with the roller  12 , or may be an existing detector already present in the rotary system. Preferably, detector  18  is an ultrasonic sensor that uses ultrasound to detect breaks in the web medium  1 . Upon the occurrence of a break in web medium  1 , as indicated by  20 , resulting in a break-off of the web medium, shown as dashed line  22 , roller  12  rotates (in the embodiment shown in a clockwise fashion (arrow  24 )) so as to wrap web medium  1  (broken web medium  22 ) around roller  12  and prevent the web medium from going back into the rotary process  2 . End shaft portion  16 , and its counterpart on the opposite end of roller  12 , allow roller  12  to rotate without preventing web medium  1  from travelling backward through roller  12 .  
         [0034]    Referring to FIGS.  6 - 7 , an embodiment of the physical apparatus  30  incorporating the web press rotary equipment protection device  10  (alternatively “roller” or “cylinder”) is illustrated. In this embodiment, device  10  is driven by a pneumatic system when engaged. The roller  10  includes a frame  32  supported by a base  34 . Preferably, frame  32  is constructed from modular extrusion material. Roller  10  is supported by a shaft portions  36   a - b  which engage clutch bearings  38   a - b , which are secured to frame  32 . Roller  10  is preferably aluminum and includes a web medium opening  11  (e.g., a milled slot) in order to accommodate passage of a web medium. Preferably, the medium passage slot is substantially transverse to a length of the roller. In general, the medium passage slot is located along a diameter of the roller such that the web medium may pass through a central axis of the roller along the diameter. Because the system is driven by pneumatics, a pneumatic solenoid  40  is used to index roller  10  to assure that web medium opening is level. In one aspect, the solenoid  40  can be of a single acting variety with spring return. Solenoid  40  is mounted to frame  30  and when its pneumatic piston is extended it comes in contact with an alignment hole located in coupler  42  which consists of two aluminum couplings connected by a flexible rubber insert for alignment of roller  10 . Shaft portion  36   b  is driven by motor  44  which is preferably a pneumatic vane-type directional motor. Medium sensor  46  monitors for breakage of the medium as it passes through opening  11 . Reserve air can be supplied to and controlled by air regulator  50  by ballast tank  48 . In this embodiment, air is supplied to solenoids  52  and  54 , which are preferably 115 VAC ⅛″ and 115 VAC ½″ for indexing solenoid and motor input, respectively. Solenoids  52  and  54  are both mounted to electrical enclosure  56 , which contains all of the necessary electrical components, included, in a preferred embodiment, timing relays, interlock relays, transformers, emergency stop relays, fuse block assemblies, on-off switch, etc. Switch  58  is used to turn roller  10  on or off as desired. Use of the present invention with a pneumatic drive system is preferred for press speeds up to approximately 2000 feet per minute.  
         [0035]    Turning to FIGS.  8 - 9 , another embodiment of the present invention is shown. As shown, a similar frame  32  to that of FIGS.  6 - 7  is included. In this embodiment, roller  10  is driven by an electric motor  60 . The motor  60  works with clutch  62  and clutch bearing  64  to drive roller  10 , preferably in a single direction (i.e., lock up occurs when roller  10  is driven in the opposite direction so as to protect the web medium). Again, sensor  66  monitors the medium for breaks. Control for motor  60  can be accomplished using electrical interface box  66 , which includes PLC and drive motor drive control components. In order to synchronize the press speed with the roller speed, a speed-following tachometer or encoder  68  is interfaced with box  66 . Use of the present invention with an electric drive system is preferred for press speeds greater than approximately 2000 feet per minute.  
         [0036]    [0036]FIG. 10 is an operational diagram of one embodiment of press rotary equipment protection system  100  with pneumatic motor drive in accordance with one aspect of the present invention. An electric motor driven version is also contemplated. The pneumatic version of the anti-wrap system works off of a principal of compressed pneumatic air. In operation, house air is brought into the anti-wrap systems by air regulator  102 , preferably set at 100-120 PSI, from the resident air supply  104   a . From the regulator the air is sent to air ballast tank  104 . The ballast tank  104  supplies air in this embodiment when system  100  is activated (i.e., when it is desired to rotate roller  10 ). Air leaves the ballast tank  104  and is directed via tubing  106  (e.g., ½″ ID plastic tubing) to the dual electro-pneumatic solenoids  108 , which are used as the Main Motor Feed. It is important to note that air, while available, is not used to rotate the roller  10  until after a break in the web medium is detected. To that end, air pressure is blocked off at the entrance to the solenoids  108  until the ultrasonic or other sensor  110  detects a break in the web or other type of material. When system  100  is inactive (i.e., no web medium break detected), an indexing pin  112  is engaged which maintains medium opening  114  in a parallel position with respect to the web medium. Once the press reaches an arming speed of 15-20%, the indexing pin  112  is retracted and the system remains in a ready state.  
         [0037]    If no breaks in the web (or other type of material) occur, the system  100  remains ready to be activated. When a break occurs, the high-speed ultrasonic sensor  110  receives a change in condition and sends a signal to the electrical interface box  116  where, in a preferred embodiment, two timing circuits (not shown) are triggered. In this case, the first timing circuit is for the pneumatic motor  118  and is used to engage the dual electro-pneumatic solenoids  108 , which supply the air necessary for the motor to run. The first timer is set to run for approximately six seconds. Two solenoids are required due to the airflow requirements of the motor. Once the motor  118  is activated, the roller  10  will start to gain momentum, in this embodiment turning clockwise—as viewed from the operator side. Once the roller  10  contacts the loose web, the lead edge of the front and back slots which contain the two respective knife blades  120  puncture the web and hold it as the web is wrapped around the cylinder. The roller  10  then increases speed until it attains a speed corresponding to the speed at which the press is running (same surface speed) at which time the roller surface speed will be limited by the speed of the press as the press starts to slow down. In this way, medium exiting the rotary printing unit can act as a breaking mechanism which in turn can serve to restrain the pneumatic motor  118  via the taught or tightened paper. This results in the roller surface speed being equal or substantially equal to the press speed.  
         [0038]    The second timer can also be simultaneously activated to keep the indexing pin  112  in a retracted position until the motor  118  and roller  10  come to a complete stop. In a preferred embodiment, this timer can be set for approximately a fifteen second delay. After each timer reaches its time-out the respective timer resets itself and the system is ready to be reset. In order to remove the paper that is wrapped up around the roller, such as with a knife, the operator turns the power to the system off. Once the web medium is removed, the roller  10  can be turned by hand until the indexing pin  112  contacts the indexing stud located on the drive coupler. Electrical connections electrical interface box  116  include: A) 115 VAC Power, B) 15-20% Press Speed Interlock, C) Optional Emergency Stop Input From Press, D) Output to Main Electro-Pneumatic Solenoids, E) Electrical Connection to Ultrasonic Sensor, and F) Connection to Indexing Electro-Pneumatic Solenoid.  
         [0039]    Another version of the system employs the use of an electronic servo drive motor, which takes the place of the pneumatic system entirely. The electronic servo drive option is for higher speed applications and the drive motor runs at 30% higher speed than the press for the first four revolutions and then matches press speed exactly by using a reference encoder.  
         [0040]    A method of protecting a rotary web press is also disclosed. The method comprises: providing a roller having a web medium passage slot for receiving a web medium therethrough from the rotary web press; and passing the web medium through the web medium passage slot of the roller. The addition, the method can further include: detecting a break in the web medium; rotating the roller in response to detecting the break; engaging the medium passing through the medium passage slot of the roller; and wrapping the web medium around the roller.  
         [0041]    The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.