Log saw machines can be used to cut long rolls of paper products, such as paper towels and toilet paper into shorter rolls for marketing to consumers. As shown in
Conventional grinding wheels 102 & 104 used on tissue log saw machines employed a vitrified surface that causes the problems of sparking, loose grit, and a constant need for cleaning and adjustment. As the industry changes and the papers being cut become softer and lighter, the rolls of paper become more difficult to cut, and fires also become a problem.
Grinding wheels with cubic boron nitride (CBN) were introduced, generally in six inch or four inch diameters with a one-quarter inch face. The CBN grinding wheels sharpen better with less nicking and chipping than those with previously used abrasives. But due to conventional types of grinding systems, it is very difficult to design a bond between the grinding wheel and the CBN surface that breaks down properly under operational circumstances.
Besides the problem of designing a wheel that breaks down properly, there are three types of glue involved in the operation that affect the grinding wheels: transfer glue, the tail tie, and core glue. These glues load up on the face of the blade causing poor cut quality. Attempts to improve conventional grinding wheels have met little success. For example, using multiple types of CBN generally fails, as the various glues load up both types of CBN used. Lubricants were also introduced to help fight the glue problems, but provided little improvement. Costs to shut down and clean is a large cost to the industry in both production and safety. For example, the average cost of a production line can be around $1500.00 USD per hour. Moreover, there have been numerous accidents at all mills while operators cleaned the sharp blades and grinding wheels.
Conventionally, operators need to manually set the grinding wheels 102 & 104 to the orbital blade 100 for sharpening. This procedure is conventionally performed every 4-5 hours of production. Conventional metal pneumatic cylinders may be used to bring the grinding wheels 102 & 104 into the close vicinity of an orbital blade 100 for a sharpening cycle, and then used to remove or “pull back” the grinding wheels 102 & 104 after sharpening.
Air pressure is not conventionally used to tension the grinding wheels 102 & 104 against the orbital blade 100 during the sharpening itself. Conventionally, mechanical sharpening pressure, or tension, must be custom-set by hand and by human judgment. As shown in
Conventionally, if the stones, i.e., the grinding wheels 102 & 104 are not setup correctly then the orbital blade 100 becomes damaged and must be changed prematurely. Moreover, the setup of the grinding wheels 102 & 104 and adjustment is not a reliably safe procedure for human operators, as the exquisitely sharp orbital blade 100 and other potentially hazardous hardware are nearby at all times during the adjustment processes.
Overview
This disclosure describes a blade sharpening system for log saw machines. The example blade sharpening system has multiple advantageous components and features. Example grinding wheels and an example tensioning system are described below.
Example Grinding Wheels
In an implementation, the example multiphase grinding wheels 300 described herein each include a grinding face that has two or more concentric contact rings. For example, a first concentric contact ring 302 has a relatively hard grinding abrasive, such as particles or grit of cubic boron nitride (CBN), wurtzite boron nitride, silicon carbide, ceramic, or diamond (CBN will be used herein as an example to represent all hard abrasives), and is combined on the grinding face of the multiphase grinding wheel 300 with a second concentric contact ring 304 of a fiber pad. Such a two-phase contact surface can provide numerous advantages, such as:
The second concentric contact ring 304 made of a fiber pad or padding can be constructed of a solid-woven or nonwoven abrasive pad (e.g., as available from Norton or 3M) bonded to a flexible or non-flexible backing pad. The term “fiber abrasive pad” will be used representatively herein to designate the class of possible nonwoven and solid-woven fiber pads that can be used, including those with various degrees of abrasiveness ranging from almost zero to slightly aggressive. The second concentric contact ring 304 has less abrasive quality than the first concentric contact ring 302 that grinds the cutting edge during sharpening. However, the fiber abrasive pad of the second concentric contact ring 304 hones and polishes the sharp cutting edge created by the more aggressive first concentric contact ring 302. The fiber abrasive pad may have its own abrasive agents, such as a sparse fine powder of CBN impregnated in the fibers, or nano-, microscopic, or fine particles of another abrasive grit, but these are not as aggressively abrasive as those of the first concentric contact ring 302.
The second concentric ring 304 consisting of the nonwoven fiber pad is wide enough to spread the contact pressure between the grinding wheel 300 and the log saw blade 100 over a larger surface area than the contact surface area of the first concentric ring 302 would have if alone, and thereby reduces distortion and deformation of the blade 100 caused by the contact pressure. This improvement over conventional blade deformation also reduces squaring and scalloping of the blade 100.
The nonwoven fiber pad of the second concentric ring 304 can hone and polish the cutting edge of the log saw blade 100 as the same edge is being sharpened by the first concentric ring 302 of the grinding face that has the more aggressive abrasive for sharpening.
The nonwoven fiber pad of the second concentric ring 304 can also reduce sparking caused by the grinding and sharpening and reduces the risk of fire. In addition, the nonwoven fiber pad can buffer the tensioning adjustment between the grinding wheel 300 and the log saw blade 100 since the nonwoven fiber pad makes the contact surface broader and also changes the feel when the grinding wheel 300 and the blade 100 make contact. This slight difference in the contact between grinding wheel 300 and blade 100 can simplify setup of the grinding wheels 300 against the log saw blade 100.
The nonwoven fiber pad can also remove glues and varnishes picked up by the log saw blade 100 from the paper rolls being cut, even while the first concentric ring 302 of the grinding face is maintaining the bevel angle of the cutting edge of the log saw blade 100.
In an implementation, the backing plate of the grinding wheel 300 may also be made flexible to increase the flexibility of the pressure contact between the grinding wheel 300 and the log saw blade 100.
In an implementation, the second concentric ring 304 of the grinding face and its fiber pad reduces and tempers the aggressiveness of the first concentric ring 302 in sharpening the cutting edge of the log saw blade 100. As shown in
Single and combination grinding wheels 300 may use variations in the width of the grinding face, and in the grit and bonding combinations. In an implementation, the fiber pad can be either a solid-woven or a nonwoven material. In an implementation, the fiber material is fixed to the backing plate, instead of being fixed to the conventional narrow race of a conventional grinding wheel 102 & 104. The backing plate itself may be one of numerous materials that can be flexible, non-flexible, solid, or slotted.
The abrasive for use on a concentric contact ring 302 can consist at least in part of CBN, diamond, or ceramic particles, for example, and can be bonded to a cloth material or to the backing plate by electroplating, coatings, resins, glues, fibers ceramics, vitrification, or other types of bonding. Thus, conventional or non-conventional grinding materials can be combined with cloth and the backing plate.
In an implementation, an example grinding wheel with a wider grinding face than conventional grinding wheels increases the surface area of contact with the cutting blade, the surface area of contact calculated to minimize deflection of the blade 100 off a narrow point.
In an implementation, a grinding wheel 300 with an increased coarseness of the grinding surface 302 allows longer run times, reducing glue buildup. The cut quality improves and persists for longer periods of time, and fire hazards are also reduced. A longer-running grinding wheel 300 also reduces human entry into the saw house or booth, improving safety and production.
In an implementation, the wider combined contact surfaces 302 & 304, as compared with conventional grinding wheels, allows coarser CBN or other abrasive to be bonded to the backing plate for more aggressive grinding and/or a longer grinding surface life. The backing plate can be metal, plastic, or a ferrous or non-ferrous material.
Example Tensioning System
For tensioning the multiphase grinding wheels 300 (or conventional grinding wheels) against the orbital cutting blade 100, an example air bladder system provides a dynamically correct sharpening tension between the grinding wheels 300 and the orbital blade 100 being sharpened.
With the example air bladder system using fluidic muscles 804, the sharpening tension can also be adjusted remotely, to remove human operators from the hazards of manual adjustments made around sharp and dangerous blade edges 100. In an implementation, the remote adjustment may even be automated. Further, when both improvements are used together, i.e., multiphase grinding wheels 300 used together with the fluidic muscle tensioners 804, superior blade sharpening is achieved and the longevity of both the orbital cutting blade 100 and the multiphase grinding wheels 300 is increased.
The example system using air bladders 804 has some advantages. First, there are no rigidly mechanical parts to wear down as in a piston-style pneumatic cylinder. Second, the air bladder 804 and its air contents maintain some elasticity so that the grinding wheel 300 is not forced into the orbital blade 100 with an unyielding force that damages either the blade 100 or the grinding wheel 300 when maladjusted. Third, since the sharpening pressure being applied is more likely optimal, and self-adjusts in real-time because of the elasticity of the air bladder 804, all the interfacing parts last much longer.
In an implementation, the example system may include remote control that takes human operators out of the “saw house” or saw booth, the enclosure in which the sharp blades and potentially hazardous machinery reside. The remote control capability allows the operator to adjust the pneumatic sharpening tension from a safe distance. In an implementation, the adjustment of sharpening tension is handed over to computer control, or to a programmable logic controller (PLC).
In an implementation, the grinding wheels 300 & 300′ are set a distance of 0.060 inch from the blade 100 before being brought into contact with the blade 100 by the fluidic muscles 804 for sharpening.
The air bladders 804 actuate the grinding wheels 300 into the orbital blade 100. The regulators 1102 & 1102′ control the amount of maximum pressure between a grinding wheel 300 and the orbital blade 100.
In an implementation, an adjustable shaft 802 with lock can set the grinding wheel 300 to a specific distance from the blade 100. These features allow the grinding wheels 300 & 300′ to make contact at the same time with the blade 100. Then, the grinding wheels 300 & 300′ float with any lateral motion of the blade 100 as the air bladders 804 & 804′ apply the sharpening tension.
An operator or machine performs an example setup procedure consisting of 1) setting the “chord length” or the overlap of the grinding wheel to the blade; 2) setting each grinding wheel approximately 0.060 inch away from the blade; 3) starting the blade rotating and actuating the grinding system; 4) increasing the air pressure until one grinding wheel starts to spin lightly; 5) bringing in the second grinding wheel until it starts to spin; 6) and adding, for example, another two PSI of air pressure to the sharpening tension of each grinding wheel, e.g., using a pressure indicator. This example technique has the advantage that the blade is rotating when adjusting the grinding wheels. This eliminates frequent visits into the saw house to adjust the grinding wheel tension, and improves production up-time.
Example Method
At block 1302, a fluidic muscle is operatively connected to a grinding wheel for sharpening a blade of a log saw machine.
At block 1304, a fluid to the fluidic muscle is regulated to maintain an effective sharpening pressure between the grinding wheel and the blade of the log saw machine.
Example Control Environment
The example blade sharpening system uses a programmable logic controller (PLC) or other computing device for electronic control of pneumatic and mechanical components.
Example device 1400 includes one or more processors or processing units 1402, one or more memory components 1404, the sharpening controller 1406, a bus 1408 that allows the various components and devices to communicate with each other, and includes local data storage 1410, among other components.
Memory 1404 generally represents one or more volatile data storage media. Memory component 1404 can include volatile media (such as random access memory (RAM)) and/or nonvolatile media (such as read only memory (ROM), flash memory, and so forth).
Bus 1408 represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. Bus 1408 can include wired and/or wireless buses.
Local data storage 1410 can include fixed media (e.g., RAM, ROM, a fixed hard drive, etc.) as well as removable media (e.g., a flash memory drive, a removable hard drive, optical disks, magnetic disks, and so forth).
A user interface device may also communicate via a user interface (UI) controller 1412, which may connect with the UI device either directly or through the bus 1408.
A network interface 1414 may communicate outside of the example device 1400 via a connected network, and in some implementations may communicate with hardware.
A media drive/interface 1416 accepts removable tangible media 1418, such as flash drives, optical disks, removable hard drives, software products, etc. Logic, computing instructions, or a software program comprising elements of the sharpening controller 1406 may reside on removable media 1418 readable by the media drive/interface 1416.
One or more input/output devices 1420 can allow a user to enter commands and information to example device 1400, and also allow information to be presented to the user and/or other components or devices. Examples of input devices 1420 include keyboard, a cursor control device (e.g., a mouse), a microphone, a scanner, and so forth. Examples of output devices include a display device (e.g., a monitor or projector), speakers, a printer, a network card, and so forth.
Various processes of the sharpening controller 1406 may be described herein in the general context of software or program modules, or the techniques and modules may be implemented in pure computing hardware. Software generally includes routines, programs, objects, components, data structures, and so forth that perform particular tasks or implement particular abstract data types. An implementation of these modules and techniques may be stored on or transmitted across some form of tangible computer readable media. Computer readable media can be any available data storage medium or media that is tangible and can be accessed by a computing device. Computer readable media may thus comprise computer storage media.
“Computer storage media” designates tangible media, and includes volatile and non-volatile, removable and non-removable tangible media implemented for storage of information such as computer readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other tangible medium which can be used to store the desired information, and which can be accessed by a computer.
Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the subject matter. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.
This divisional patent application claims the benefit of priority to U.S. patent application Ser. No. 14/274,561 to Baker, filed May 9, 2014, which in turn claims the benefit of priority to U.S. Provisional Patent Application No. 61/821,628 to Baker, filed May 9, 2013, entitled, “Blade Sharpening System for Log Saw Machine,” both incorporated herein by reference in their entireties.
Number | Name | Date | Kind |
---|---|---|---|
1551167 | Orlow | Aug 1925 | A |
2309016 | Ryan | Jan 1943 | A |
2451295 | Metzger | Oct 1948 | A |
2867063 | Metzger | Jan 1959 | A |
4173846 | Steiner | Nov 1979 | A |
5090281 | Paulson | Feb 1992 | A |
5496209 | Gaebe | Mar 1996 | A |
5503592 | Neumann | Apr 1996 | A |
5626065 | Cattini | May 1997 | A |
6062958 | Wright | May 2000 | A |
6312325 | Van Osenbruggen | Nov 2001 | B1 |
6419574 | Takahashi | Jul 2002 | B1 |
6749496 | Mota | Jun 2004 | B2 |
7004823 | Kisboll | Feb 2006 | B2 |
7527546 | Nishihara | May 2009 | B2 |
8801497 | Schwappach | Aug 2014 | B2 |
20030162488 | Bancon | Aug 2003 | A1 |
20040235406 | Duescher | Nov 2004 | A1 |
20060211353 | Kodani | Sep 2006 | A1 |
20120184186 | Graham, Jr. | Jul 2012 | A1 |
20130324014 | Dovel | Dec 2013 | A1 |
20140154961 | Fiore | Jun 2014 | A1 |
Number | Date | Country | |
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20160236369 A1 | Aug 2016 | US |
Number | Date | Country | |
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61821628 | May 2013 | US |
Number | Date | Country | |
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Parent | 14274561 | May 2014 | US |
Child | 15138211 | US |