Patent Publication Number: US-2021178626-A1

Title: Apparatus and Method for Automated Blade Change for Tissue Saw

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional application of application Ser. No. 16/109,028, filed on Aug. 22, 2018, which claims the benefit of provisional application Ser. No. 62/553,244, which was filed on Sep. 1, 2017, the disclosures of which are incorporated by reference herein. 
    
    
     SUMMARY 
     This disclosure relates to a system for the automatic changing of a blade for a tissue log saw. The blades for the tissue log saw are stored in an array of storage units. Each storage unit in the array is configured to store a blade for the saw. Each storage unit is also extendable from the array to allow a stored blade to be loaded from the storage unit to the cutting head and to allow an expired blade to be received into the storage unit from the cutting head. When the array is interfaced with the saw, at least one storage unit in the array is empty to receive an expired or used blade from the saw, and the remainder of storage units in the array are preloaded with blades for the processing operation. The system facilitates tracking and inventory of blades, and allows the array of storage units to be moved to a location in a converting facility suited for inspection of the blades, removal of the blades from the storage units, and insertion of blades into storage units. The system minimizes the interaction of machine operators and maintenance personnel with the blades. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG. 1  illustrates in a top plan view an array moving into position relative to a saw with the array having an empty storage unit and other storage units in the array each having a blade, with a cutting arm of the saw in an exchange position to transfer an expired blade into the empty storage unit of the array. 
         FIG. 2  illustrates the array releasably connected with the saw, and the empty storage unit in position to enter the saw house to receive the expired blade from the saw cutting arm. 
         FIG. 3  illustrates the empty storage unit entering a saw house of the saw. 
         FIG. 4  illustrates the empty storage unit in position to receive the expired blade from the saw cutting arm. 
         FIG. 5  provides further detail of the exchange of the expired blade between the saw cutting arm and the empty storage unit with a tool holder receptacle of the saw arm activated to engage a tool holder of the saw blade and a tool holder receptacle of the storage unit deactivated prior to engagement of an opposite side tool holder of the saw blade. 
         FIG. 6  provides further detail of the exchange of the expired blade between the saw cutting arm and the empty storage unit with the tool holder receptacle of the saw arm activated to engage the saw blade tool holder and tool holder receptacle of the storage unit activated to engage the opposite saw blade tool holder. 
         FIG. 7  provides further detail of the exchange of the expired blade between the saw cutting arm and the empty storage unit with the tool holder receptacle of the saw arm deactivated to release the saw blade tool holder and tool holder receptacle of the storage unit activated to engage the opposite side saw blade tool holder. 
         FIG. 8  shows the previously empty storage unit with the expired blade moving away from the saw cutting arm. 
         FIG. 9  shows the previously empty storage unit with the expired blade moving back to the array. 
         FIG. 10  shows a full storage unit with a next in queue stored blade moving into the saw house. 
         FIG. 11  shows the full storage unit with the next in queue stored blade advancing toward the saw cutting arm. 
         FIG. 12  provides further detail of the exchange of the next in queue stored blade between the full storage unit and the saw cutting arm with the tool holder receptacle of the saw arm deactivated prior to engagement with the saw blade tool holder and tool holder receptacle of the storage unit activated to engage the opposite side saw blade tool holder. 
         FIG. 13  provides further detail of the exchange of the next in queue stored blade between the full storage unit and the saw cutting arm with the tool holder receptacle of the saw arm activated to engage the saw blade tool holder and tool holder receptacle of the storage unit activated to engage the opposite saw blade tool holder. 
         FIG. 14  provides further detail of the exchange of the next in queue stored blade between the full storage unit and the saw cutting arm with the tool holder receptacle of the saw arm activated to engage the saw blade tool holder and tool holder receptacle of the storage unit deactivated to release the opposite side saw blade tool holder. 
         FIG. 15  shows a now empty storage unit moving away from the saw cutting arm. 
         FIG. 16  shows the now empty storage unit back in the array of storage units. 
         FIG. 17  shows the saw cutting arm returning to a cutting position. 
         FIG. 18  shows a top view of an exemplary blade cleaner associated with the array and storage units. 
         FIG. 19  shows a cleaning member of the blade cleaner of  FIG. 18  in a retracted position with the storage unit arm and blade tool holder not shown for ease of illustration. 
         FIG. 20  shows a cleaning member of the blade cleaner of  FIG. 18  in an extended position with the storage unit arm and blade tool holder not shown for ease of illustration. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary system  20  described below and shown in the drawings includes an array  22  that interfaces with a saw  24  and provides blades  26  for a cutting arm  28  of the saw through a plurality of storage units  30  arranged in the array. Each storage unit  30  in the array  22  is configured to store a blade  26  for the saw  24 . The saw  24  may be configured to cut tissue logs  32  entering a saw house  34  on a conveyor  36 . In a general sense and as further modified as described below, the saw  24  and the cutting arm  28  may be of the type, for instance, as shown by way of example and not in any limiting sense, in U.S. RE30,598, U.S. Pat. Nos. 5,557,997, and 6,123,002 the disclosures of which are incorporated by reference herein. The array  22  of storage units  30  could thus contain many blades  26  for the saw  24  for a particular saw cutting operation or procedure as may be required by the application. As will be described below, each storage unit  30  is configured to store, receive, and transfer the blade  26 , whether a new blade, an expired blade, or partially-used blades for later use. The array may move in a direction generally parallel to the saw blade center axis. The movement may be independent of the saw or the array may move once coupled with the saw  24 . In addition or alternative, the storage units in the array may move in a direction generally parallel to the saw blade center axis relative to the saw once the array is coupled to the saw. In addition or alternative, the storage units may be stationary in the direction of travel of the saw blade center axis once the array is coupled with saw, and the saw may move as necessary. In each case, the array and/or storage unit may move, as needed to receive an expired blade, and load and mount a next-in-queue blade for use on the saw cutting arm. As used herein, the term “expired” means that the blade condition is used such that it is no longer suitable for the particular processing operation currently being conducted on the saw, and not necessarily that the blade is to be scrapped, and the term “new” means blades that have been readied for a particular saw processing operation, and not necessarily that the blades are new from a vendor or supplier or have never been used. 
     The array  22  may comprise a housing  40  configured to hold the plurality of storage units  30 . The array  22  may be portable and may be detachably mounted to the structure comprising the saw  24  and saw house  34 . An interface  42  may be built into a wall panel or other structural member of the saw house  34  to provide a detachable mount for the array  22  of storage units  30 . The interface  42  may allow the array  22  to be physically, mechanically, electrically, and/or electronically detachably mounted to a wall panel or other structural member of the saw house  34 . A system of cooperating connectors, for instance, pneumatic or hydraulic actuators  43  may engage with each and/or cooperate to secure the array  24  to the saw housing  34 . The interface  42  may provide a connection point  44  for the array  22  to mechanically connect with the saw. For instance, in one embodiment, the array may have a linkages or mechanical actuators that connect with cooperating linkages or mechanical actuators on the saw via the interface, thereby allowing the linkages on the array to be actuated via the saw. In other words, the linkages on the array may connect with linkages on the saw when the array is detachably mounted to the saw, so the linkages on the array are an extension of those on the saw. In this manner, movement of the storage unit between the retracted and extended position, and actuation of the storage unit blade tool holder receptacle, all of which will be described below, may be accomplished via mechanical linkages extending from the saw to the array. This would dispense with the need to provide electronic control systems on the array. In addition or alternative, the array  22  may be configured to draw electrical power and/or pneumatic or hydraulic fluid sources from the saw  24 . The array  22  may also have an on-board rechargeable battery to power electrical and electronic equipment on the array or draw electrical power from another external source (not shown). The array  22  may also be equipped with pneumatic or hydraulic actuators. The interface  42  and the connection point  44  may be configured to supply the array  22  with pneumatic or hydraulic fluid from the saw. The array  22  may also draw pneumatic or hydraulic fluid from the facility through external connections (not shown). The array may also have on board pumps to supply pneumatic or hydraulic fluid to respective components on the array. Accumulators, valves, and other conventional equipment needed for pneumatic or hydraulic actuation systems may be provided on the array, as applicable. As will be explained below in greater detail, the array  22  may also be electronically coupled to the saw  24  at the interface  42  and connection point  44  so control signals generated by the saw may be transmitted to the array for certain array based functions, and signals from the array may be transmitted to the saw for certain saw based functions. The transmission may be through a network  46  and may be wireless  48 . The array  22  of storage units  30  may be provided in the form of a cart with wheels (e.g., swivel casters)  50  that may be maneuvered to a position that allows the cart to mount directly with the saw house  34  via the interface  42 . The movement may be manual or automated via a track or other guidance system. The array of storage units in the form of a rolling cart allows the array to be maneuvered into the tight spaces on the converting floor that are usually found around the saw house and structure of the saw. 
     Once all the blades in the array of storage units are expired, the array of storage units can be unmounted from the saw house and transported to an area where blade disposition occurs. The blade disposition location is preferably not on the converting floor, but in a more remote area with plenty of space, lighting, and other support for safe handling and disposal of the expired blades. 
     For a saw or saw cutting process, two or more portable arrays of storage units may be provided. For example, once all the blades in the “in use” array of storage units are expired (e.g., of an unusable diameter for the particular processing operation currently being conducted), the second fully stocked array of storage units with new blades may be brought online, mounted to a wall panel or other structural member of the saw house via the interface, and quickly exchanged with the array of storage units with the expired blades. In this way, the restocking of the array of storage units reduces potential operational bottlenecks in the saw cutting operation. 
     In another aspect, the arrays may be part of a subscription system provided by a supplier. The supplier may have multiple arrays that may be provided to a customer for use. When the blades in a particular array are expired, the customer may return the array to the supplier for a new array of blades. The array may form a part of a shipping container to allow transport of the array between the supplier and the customer. Once an array is returned to the supplier, the array may be restocked with new or refurbished blades and calibrated for reuse. Functional aspects of the array may be checked and repaired as necessary. The supplier may collect and analyze blade operational data from returned arrays and provide recommendations and service bulletins in connection with the array or saw to customers. The data collection and analysis may be used for general product improvement. 
     The array  22  of storage units  30  may have a power supply, sensors, motion detectors, a computer processor, a memory storing data, and computer equipment that allows the array to connect to the network  46  with a like or another computer system or programmable logic control for the saw via the interface  42  and the connection point  44 . The array memory may store data structures of information  52  regarding the blades that are currently stored in the unit. Each storage unit  30  may also be equipped with like equipment so the blade information is maintained at the storage unit level. In one example, the array and/or the storage unit may be configured with a RFID device (e.g., a label or tag). The saw  24  may be configured to read and/or write to the RFID device on the array, storage unit or blade. The information  52  may include blade diameter, blade material, last saw cutting operational data, last inspection, last sharpening, last run-time, cumulative run-time, etc. The blade information  52  may also include information about a specific blade or storage unit that should be bypassed in the array and not used in the saw cutting operation because of a maintenance condition or expired inspection status. Information  52  regarding a blade may be transferred on the network  46  between the saw  24  and the array  22  so the array may correlate specific information about a blade and a storage unit  30 . Information  52  from the saw  24  may be downloaded to the array  22  so the array stores information about each blade and its respective storage unit  30 . The download of information may occur during operation with the array connected to the saw and/or prior to removing the array from the saw. The download of information  52  may occur via the network  46  or via the interface  42  and the connection point  44 . Information  52  including blade data from the array  22  may also be uploaded to the saw  24  once the array is mounted to the saw at the interface  42 . The upload of information  52  may occur via the network  46  or via the interface  42  and the connection point  44 . Storing information about each blade via the array allows for the reuse of blades. For instance, a blade that has been previously used in connection with processing large diameter rolls may still have a diameter sufficient to allow processing for smaller diameter rolls. If a blade became too small for a particular product or processing operation at the time it was in use, it could be retrieved and used again in connection with a subsequent product or processing operation. An array of storage units containing partially used blades could be used in a different saw cutting operation, and the array or storage unit RFID label information may be uploaded to the saw so that the saw and array may synchronize (and/or the storage units may sequence) in a manner necessary to mount the correct diameter blade for the desired process. 
     Each blade  26  may define a plane  60  ( FIG. 5 ) with one side facing the cutting arm  28  of the saw  24  and the opposite side of the plane facing the storage unit  30 . Each blade  26  may be configured with a tool holder  62  on the saw cutting arm  28  facing side of the plane  60  and a tool holder  64  on the storage unit  30  facing side of the plane. The saw  24  may be configured such that the saw cutting arm  28  has a tool holder receptacle  66  adapted and configured to engage the blade tool holder  62  on the saw facing side of the blade. Each storage unit  30  may have a tool holder receptacle  68  adapted and configured to engage the tool holder  64  on the storage unit  30  facing side of the blade. Each storage unit  30  may be configured to store the blade in a generally vertical configuration such that the axis of rotation  70  ( FIG. 1 ) of the stored blade is generally horizontal and parallel to the direction of the log travel  72  ( FIG. 1 ). The array  22  may also include one or more empty storage units  30 ′ ( FIGS. 1-3, 15-17 ) to the extent the saw already has one or more blades already mounted in the saw. Each storage unit  30  may have a hollow interior sufficient to accommodate the geometry of a blade  26  and an opening into the hollow interior sufficient to expose the storage unit tool holder receptacle  68  and allow the blade to be received in the hollow interior of the storage unit. The tool holder receptacle  68  of the storage unit  30  secures the blade in the hollow interior to prevent unwanted movement of the blade in the storage unit. The tool holder receptacle  68  in the storage unit may be similar or cooperate with the tool holder receptacle  64  used on the saw cutting arm to make exchange between the saw cutting arm and the storage unit simple and universal. In one example, the blade  26  may be secured on the saw arm  28  and inside the storage unit  30  with a collet mechanism. In this example, the blade tool holder  62 , 64  may comprise a male end of a collet that is mounted on both sides of the center of the blade  26  at the blade cutting axis  74  ( FIG. 1 ), and both the saw arm and the storage unit tool holder receptacles  66 , 68  may comprise the cooperating female portion of the collet mechanism. The collet mechanism on the saw arm  28  and the storage unit  30  may oppose each other when the storage unit is brought into register with the saw cutting arm. In other words, the male collet on one side of the blade may interface into the saw arm and the male collet on the opposite side of the blade may be for interface into the storage unit. In the alternative to a collet mechanism, the tool holder receptacle on the storage unit or saw cutting arm may be a chuck mechanism, a jaw-chuck mechanism, or other cooperating system of tapered sleeves configured to receive an arbor, tapered sleeve or fixture mounted to the saw blade. 
       FIGS. 1-17  illustrate an exemplary sequence of operations to remove an expired blade from the saw arm  28  and to install the new, next in queue stored blade  26 ′ onto the saw arm. The array  22  may be configured such that motion of one storage unit in the array may be independent of the motion of another storage unit. For instance, each storage unit  30  of the array may be configured to move linearly from the array into the saw house  34  independently of another storage unit. In addition, the array of storage units  30  may also be configured to move in the direction of log travel  72 . When a blade exchange needs to be performed, the saw cutting arm  28  may go to a pre-determined position, for instance, left of the cutting gap  76  ( FIGS. 1-2 ) in the conveyor  36 . The empty storage unit  30 ′ in the array of storage units may move from the retracted position in the array ( FIGS. 1-2 ) to the extended position away from the array and into the saw house such that the empty storage unit is placed in alignment with the saw cutting arm as shown in  FIG. 3 . Then, as shown in  FIGS. 4-5 , the entire array  22  of storage units  30  may move the appropriate distance in a direction  78  parallel to the direction  72  of the travel of the log  32  to bring the empty storage unit  30 ′ to a position immediately adjacent to the saw cutting arm  28 . As shown in  FIG. 6 , the tool holder receptacle  68  on the empty storage unit  30 ′ may then secure the blade tool holder  64  on the storage unit side of the blade  26 . At this point, the storage unit  30  may be physically connected to the saw  24 . As shown in  FIG. 7 , the saw cutting arm tool holder receptacle  66  may then release the blade tool holder  62  on the saw cutting arm  28  side of the blade  26 . At this point, the transfer of the blade from the saw cutting arm to the storage unit is complete. As shown in  FIG. 8 , the array  22  of storage units  30  may then move away from the saw arm  28  in a direction  80  parallel to the log travel direction  72  a distance sufficient to enable the tool holder  62  extending from the saw cutting arm side of the blade  26  to clear from the saw cutting arm  28 . As shown in  FIG. 9 , once clear, the storage unit  30  may move from the extended position in the saw house  34  to the retracted position back into the array  22 . 
     To load the new, next in queue blade  26 ′, the selected storage unit  30 ″ will move from the retracted position within the array  22  to the extended position away from the array into the saw house  34 , as shown in  FIG. 10 . Then, as shown in  FIGS. 11-12 , the array  22  of storage units will move the appropriate distance in the direction  78  to interface and engage the tool holder  62  on the saw side of the blade  26  to the tool holder receptacle  66  on the saw cutting arm  28 . As shown in  FIG. 13 , the saw cutting arm tool holder receptacle  66  will secure the blade tool holder  62  on the saw cutting arm side of the blade. At this point, the storage unit  30  and saw  34  are connected. As shown in  FIG. 14 , once secured on the saw arm  38 , the storage unit tool holder receptacle  68  will release the blade tool holder  64  on the storage unit  30  side of the blade  26 ′. As shown in  FIG. 15 , the entire array  22  of storage units  30  may move in the direction  80  a distance sufficient to allow the tool holder  64  of the storage unit  30  side of the blade  26 ′ to clear the storage unit. As shown in  FIG. 16 , once clear, the storage unit  30  may retract back into the array  22  of storage units. The retracted storage unit  30  is now considered the empty storage unit in the array of storage units and will be the next storage unit to receive an expired blade as shown in  FIG. 17 . Equipped with the next in queue blade  26 ′, the saw  24  can resume cutting operations. The sequence of exchange may reoccur until all the blades in the array of storage units are expired. At this point, a new array of storage units with a complement of new blades may be swapped out with the array of expired blades. Although the description and drawings show the saw cutting arm and storage unit with a tool holder receptacle comprising a female collet portion and the blade tool holder comprising a male collet portion extending from the saw side of the blade and storage side of the blade, the features may be reversed. 
     The array  22 , the storage unit  30 , or the saw  24  may be configured with a blade cleaner  90  to allow for cleaning of the blade  26 .  FIGS. 18-20  shown one embodiment where the storage unit  30  of the array is provided with the blade cleaner  90 . In this configuration, the blade cleaner  90  may be provided with a cleaning member  92  for engaging one or both sides of the blade  26  and removing adhesive or other residue from the saw cutting operation. The cleaning member  90  may comprise a brush, a moistened pad, or sponge. Cleaning fluid may be provided to the cleaning member to assist in the cleaning. As shown in  FIGS. 19 and 20 , the cleaning member  94  may be mounted on a slide  94  having a fixed portion operatively mounted to a side wall or structural member of the array  22  or storage unit  30  and an extension portion slidably connected to the fixed portion to move between a retracted position ( FIG. 19 ) in which the cleaning member  92  is spaced from the blade  26 , and an extended position ( FIG. 20 ) in which the cleaning member engages the blade for cleaning the blade. The slide  94  may be driven with an actuator  96  (e.g., electric, pneumatic, hydraulic) or electric motor and screw (e.g., ball screw, lead screw). The storage unit  30  may be configured to rotate the blade via the blade tool holder  64  while the slide  94  is in the extended position and the cleaning member  92  is engaging the blade  26  so as to allow the edge of the blade and a radial distance inward from the edge of the blade to be cleaned. The cleaning may occur on both sides when a cleaning member is positioned on each side of the blade. A fiber optic sensor (not shown) or feedback position (e.g. encoder) may be used to sense the blade edge and provide signals to the actuator for controlling motion of the slide  94  and the positioning the cleaning members  94  relative to the blade edge, thereby allowing the blade cleaner  90  to extend the slide  94  and the cleaning member  92  at varying distances to clean various diameter blades and to prevent cleaning member from extending too far and the blade  26  from adversely impacting the cleaning member and/or slide. In the alternative to that shown in  FIGS. 18-20 , the cleaning member  92  may be fixed in position within the array or storage unit. As the storage unit is cycled between the extended and retracted positions, the cleaning member may engage and clean the blade as the blade is moved within the storage unit between the extended and retracted positions. The cleaning operation may occur prior to moving a blade from the storage unit to the saw, for instance, as the storage unit moves from the retracted position within the array to extended position, the cleaning member may engage the blade. The cleaning operation may also occur after the blade is transferred from the saw to the storage unit, for instance, as the storage unit moves from the extended position after receiving the blade from the saw to the retracted position within the array, the cleaning member may engage the blade. The saw may also transfer the blade to the storage unit during the saw cutting operation for purposes of cleaning. For instance, the saw may transfer the blade to the storage unit and allow the storage unit to cycle between the extended and retracted positions repeatedly as needed until the blade is cleaned at which point the blade may be returned to the saw via the storage unit and back into service in the cutting operation. The blade may also be rotated in the storage unit (whether in the extended position or retracted position) so as to allow the cleaning member to engage the blade. The cleaning member may also move with rotational or translational motion relative to the blade when engaging the blade for cleaning operations. 
     In view of the foregoing, it will be seen that the several advantages are achieved and attained. The embodiments were chosen and described in order to best explain the principles of the disclosure and their practical application to thereby enable others skilled in the art to best utilize the various embodiments and with various modifications as are suited to the particular use contemplated. As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.