1. Field of the Invention
This invention is directed to a grinding apparatus for resurfacing of a rubber belt or roller while the belt or roller remains on the production line.
2. Background of the Invention
Sanforizing is a process of finishing fabric that enhances the appearance and feel of the fabric. The process ensures that the fabric will not shrink when laundered. Sanforizing is performed on fabric prior to cutting and assembling clothing. Through the sanforizing process, the fabric is heated and compressed, which causes the fibers to relax, or shrink. In this way, sanforized fabric will resist shrinkage during ironing, wearing, and especially, washing.
A sanforizer employs a seamless or endless rubber belt in a shrink zone as part of the preshrinking process. A typical endless rubber belt will have an inside circumference of 13 feet, a thickness of approximately 2.625 inches, a width of between 60 inches and 144 inches, and a weight of between 1,300 pounds and 1,700 pounds. The belt typically moves through the shrink zone at between 40 yards per minute (ypm) and 100 ypm. In the shrink zone, the belt is subjected to substantial compressive, tensile, and thermal forces. At the nip point, the belt experiences 10,000 pounds of compression per linear inch of width and as much as 22% elongation stretch. Additionally, the belt is exposed to temperatures ranging from 240° F. to 295° F. The high operating speed, extensive stresses, and elevated temperatures deteriorate the surface of the belt during the course of operation. Thus, a typical endless rubber belt will need to be resurfaced every 500,000 yards to 1,000,000 yards. As such, the belt requires resurfacing every 200 to 400 hours of use, resulting in a loss of production hours.
Resurfacing is performed to produce a pattern on the rubber belt surface, such as a scale-like pattern, and to renew the surface rubber's essential characteristics. The scale provides the necessary friction between the fabric and belt to draw the fabric through the sanforizer. The type and depth of the scale on the rubber belt surface affect the traction between the rubber belt and cloth, which is essential to the mechanical compacting of the cloth. Different fabrics can require different scales for proper compaction. The scale also allows for cooling water to be carried by the rubber belt.
Conventional resurfacing techniques involve either on-line or off-line grinders. For instance, off-line stationary lathes can be used to resurface a rubber belt or roller. However, the heavy belt or belt and roller assembly must be removed from the production line and carried to a lathe. This method requires personnel to move products that can weigh over a ton, and this method requires an extended period of downtime for the sanforizing process.
One on-line method for resurfacing belts and rollers is to use another roller with an abrasive grinding surface. Currently, this method is, by far, the most popular method for resurfacing rubber belts. The roller has a size that is approximately the same size as the width of the belt or roller that is to be ground. The roller is filled with a liquid coolant. Strips of silicon carbide grinding cloth are spirally wound around the roller to provide an abrasive surface. As the roller rotates counter to rotation of the belt, the grinding roller abrades the entire width of the belt at the one time. This method also requires the use of a solid lubricant, such as talcum power. Conventionally, up to 50 pounds of talcum powder is required to properly lubricate the resurfacing process.
However, using an abrasive grinding roller has several disadvantages. First, this method typically produces an uneven scale on the belt. Because of the large area of contact between the belt and roller, the belt surface tends to bounce away from the grinding roller, which produces horizontal chatter marks. Second, roller requires an electric motor with 15-25 hp, which increases the energy costs associated with the resurfacing process. Third, this method generates a lot of heat, causing rubber reversion, in which the rubber reverts to the gum state. Reversion causes the surface properties of the belt to change detrimentally. Poor surface properties negatively affect the cloth appearance and necessitate more frequent resurfacing.
Third, the talcum powder is difficult to contain. A large amount of talcum powder is necessary to lubricate the rubber belt and grinding roller. During resurfacing, talcum powder can spread over an area having a radius of 50 feet or more. The powder is an irritant to nearby workers, settles in the surrounding machinery, coats finished fabric, and creates a workplace hazard. In practice, the cleanup procedure for the talcum powder can take several hours after resurfacing.
Finally, the roller grinding method takes at least four hours (sometimes longer than eight hours) to complete. Often, the process has to be stopped so that the grinding cloth can be tightened and so talc and rubber dust can be removed from between the grinding cloth and the roller.
Another, less popular on-line method uses abrasive grinding belts that are essentially akin to belt sanders. The grinding belts are a few inches in width, and the grinding belts traverse the length of the belt or roller. However, grinding belts are known to have a poor rubber removal rate, they generate a large amount of heat (which can lead to rubber reversion and its associated problems), and the grit on the grinding belt quickly builds up rubber shavings.
Thus a need exists in the art for a grinding apparatus that can operate on-line, provide a uniform scale on a rubber belt, minimize sanforizer downtime, reduce energy consumption and labor costs, consistently provide high quality rubber surface, and decrease the amount of cleanup associated with the resurfacing process.
An object of the present invention is to overcome the disadvantages of conventional grinding apparatuses designed to resurface the rubber belts and rollers used in the sanforizing process.
Another object of the present invention is to provide a grinding apparatus that can grind a rubber belt or roller while the belt or roller remains on the production line. A feature of the present invention is that the grinding apparatus uses a relatively small grinding wheel that traverses a track in front of the rubber belt or roller. An advantage of the present invention is that the heavy rubber belt or roller does not have to be removed from the production line when it needs to be resurfaced. A further advantage of the present invention is that danger to personnel during resurfacing and the downtime of the machinery is substantially reduced.
Still another object of the present invention is to provide an improved grinding surface. A feature of the present invention is that the grinding apparatus uses a grinding wheel instead of a grinding roller or grinding belt. Another feature of the present invention is that the grinding wheel is made of steel with a tungsten carbide grit coating. An advantage of the present invention is that the grit of the grinding wheel does not accumulate rubber particles, the grinding wheel does not produce a large amount of heat, and the grinding wheel is able to maintain good contact with the surface of the rubber belt or roller. Additionally, the tungsten carbide grinding wheel has a long life, which reduces the lifetime operation costs associated with this method.
A further object of the present invention is to provide an automated system to grind a rubber belt or roller. A feature of the present invention is that the grinding apparatus is mounted on a motorized track that automatically and precisely traverses the grinding apparatus along the width of the rubber belt or roller. Another feature of the present invention is that the angle of the grinding apparatus and the depth of the cut can be preprogrammed or adjusted. An advantage of the present invention is that the grinding apparatus can be operated by a single person and the resurfacing process takes considerably less time to complete.
Yet another object of the present invention is to provide a grinding apparatus that greatly reduces the downtime of the sanforizer. Features of the present invention that help reduce the downtime include: the grinding apparatus operates on the production line; the grinding apparatus is automated; the grinding apparatus does not require any lubricant; and the grinding apparatus works in conjunction with an efficient dust collection means. Advantages conferred by the present invention include: the grinding time and downtime are approximately one to two hours; there is virtually no clean up time required at the conclusion of the resurfacing process because there is no lubricant to collect and the dust collection means captures almost all of the ground rubber; and the process can be initiated by one employee, who does not need to oversee the resurfacing process.
Yet another object of the present invention is to provide an easy to install grinding apparatus that can be used on multiple machines. A feature of the present invention is that the grinding apparatus has a more compact size, smaller power requirements, and lower weight as compared to conventional resurfacing techniques. An advantage of the present invention is that the grinding apparatus can be installed in much less time, moved more easily between machines, and used with existing power sources without additional modification.
The present invention provides an apparatus for resurfacing a rotating elastomer substrate, said apparatus comprising a motorized grinding wheel, said motorized grinding wheel rotating in a direction counter to the rotating elastomer substrate and having an axis of rotation parallel to the axis of rotation of the rotating elastomer substrate, wherein the perpendicular distance between the motorized grinding wheel and the rotating elastomer substrate is adjustable so as to control the amount of elastomer substrate that is removed; and a mount for said motorized grinding wheel, wherein said mount is located proximal to the rotating elastomer substrate that comprises a part of a production line and wherein the mount is capable of traversing parallel to the rotating elastomer substrate.
The invention together with the above and other objects and advantages will be best understood from the following detailed description of the preferred embodiment of the invention shown in the accompanying drawings, wherein:
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings.
As used herein, an element step recited in the singular and preceded with the word “a” or “an” should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. Furthermore, the references to “one embodiment” of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.
While the embodiments described herein relate to the sanforizing application, the grinding apparatus can be used in any technical field where a refinishing of a work piece surface is beneficial.
The present invention is directed to a grinding apparatus 10 (shown in
The presently invented grinding apparatus is placed proximal to where the belt 2 rounds the first roller 3a. As can be seen in
Typically, the grinding wheel 15 has a diameter of between six and seven inches and a grinding surface 33 width of between one and three inches; however, larger or smaller grinding wheels could be used depending on the application.
In a preferred embodiment, the grinding wheel 15 has a steel body with a tungsten carbide grit coating. However, other grinding wheels having grinding surfaces with abrasives such as alumina-zirconia, silicon carbide, boron carbide, corundum, ceramic iron oxide, diamond powder, cubic boron nitride, and ceramic aluminum oxide, among others, could also be used. Different grinding wheels, including grinding wheels with different grit sizes, can be used to produce different scales on the rubber belts or rollers. Additionally the rotational speed of the grinding wheel can be adjusted to produce a different scale. In this embodiment, the slower rotational speeds produce rougher scales.
The profile of the edge of the grinding wheel is shown in
Returning to
The grinding wheel 15 confers an important advantage on the present invention, namely that the grinding wheel 15 has a much longer operational life. Other grinding apparatuses, such as those that use abrasive wraps, abrasive belts, or ceramic stones, will need to have the abrasive element replaced or dressed with an abrasive powder, such as diamond powder, several times during the lifetime of the apparatus. Thus, the present invention reduces the cost of the resurfacing process by diminishing downtime and decreasing the cost of operation. Nevertheless, some fabrics require a specific scale on the endless rubber belt to provide the proper amount of friction. In those instances, the grinding wheel 15 can more easily and more quickly be replaced than other conventional abrasive elements. In one embodiment, the wheel 15 is removed and replaced by a wheel having a different grit type or size.
The motor 20 is secured to a mount 25. The motor 20 and mount 25 can be separate components that are joined together, or the motor and mount 25 can be integrally formed into a single piece. The mount 25 engages the track 30. The track 30 runs parallel to the width of the belt or roller. The mount 25 traverses the width of the belt or roller via the track 30. The mount 25 can travel along the track 30 using a variety of systems, including a rack and pinion system; a worm gear; or a rodless cylinder; or a carriage and rail system with the carriage driven by a linear electric motor, hydraulic or pneumatic arm, electromagnetic force, conveyor belt, or a pulley system, among others. A preferred embodiment of the track 30 and mount 25 uses a rack and pinion system, which will be described for illustrative purposes below.
As can be seen in
The grinding apparatus 10 will run along the track 30 at a constant speed set by the pinion motor 70. The grinding apparatus 10 stops automatically after reaching either end of the track 30. As can be seen in
Returning to
The motor 20, pinion motor 70, and dust collector are all electrically powered. These systems can be connected to a single control system 90; or they can operate as separate systems. As depicted in
In one embodiment, the control system 90 also includes sensors to track the status of the endless rubber belt. In one embodiment, the control system 90 accepts historical data regarding the belt and measures current use. Accordingly, the control system 90 can signal the user when the belt needs resurfacing or replacing, based on historical, current, and extrapolated future use. In one embodiment, the control system 90 is in communication with a depth sensor, such as a scanning laser or a probe tip. If the depth sensor senses that a preprogrammed limit for the difference in measured highs and lows has been exceeded, then the control system will signal to the operator that a resurfacing needs to be performed. Additionally, the control system tracks the time between resurfacing, such as by monitoring the yards of cloth that are sanforized or the revolutions of the rollers. In another embodiment, the control system 90 includes a camera which records information about the surface of the rubber belt to determine if a resurfacing is required. Additionally, as can be seen in
The amount of material removed from the belt is user-controlled, either directly or through input to the control system 90. In one embodiment of the invented grinding apparatus 10, the depth of the resurfacing is set using a manually operated wheel crank 95. In a preferred embodiment, the wheel crank 95 has a dial indicator that allows for the user to measure the high and low spots prior to grinding. Preferably, the user then sets the wheel crank 95 to a depth just deep enough to bring the belt or roller surface even with the low spots as measured on the dial. In one embodiment, the measurement is performed by bringing the grinding wheel into contact with the belt surface at various test areas to find a local minima. In this embodiment, the grinding wheel includes a sensor to determine that it has made contact with the belt, such as by determining that there is resistance during turning of the wheel.
As depicted in
Movement of the movable base 100 relative to the mount 25 is controlled using the wheel crank 95. The wheel crank 95 is in mechanical communication with a threaded rod 115. A flat projection 117 reversibly extends from a groove in the underside of the movable base 100. Extending upwardly from the flat projection 117 is a first vertical block 120, and extending upwardly from the top surface of the movable base 100 is a second vertical block 125. In one embodiment, both vertical blocks 120, 125 have collinear threaded apertures extending through the thickness of their horizontal surfaces parallel to the axis of rotation for the endless rubber belt. In another embodiment, only one vertical block 125 is threaded. In this embodiment, the threaded block 125 is fixed axially to the non-threaded block 120 with two thrust bearings, allowing screw rotation but not translation.
Beginning at the point farthest from the endless rubber belt, the wheel crank 95 engages the threaded rod 115, which extends through the first vertical block 120 on the mount 25 and then through the second vertical block 125 on the movable base 100. Rotation of the wheel crank 95 will cause the threaded rod 115 to rotate inside the threaded apertures of the first and second vertical blocks 120, 125. Because the mount 25 and first vertical block 120 are stationary, the rotation of the threaded rod 115 will cause the movable base 100 to slide towards or away from the endless rubber belt depending on what direction the wheel crank 95 is rotated. Moving the movable base 100 towards the endless rubber belt will allow for a deeper cut during each pass, while moving the movable base 100 away from the endless rubber belt will create a shallower cut during each pass. In this way, depth of the cut can be set. Further, as shown in
In addition to adjusting the perpendicular distance of the grinding wheel 15 from the endless rubber belt, the angle at which the grinding wheel 15 contacts the endless rubber belt is also subject to adjustment in some embodiments. In a default setting, the horizontal axis a of the wheel 15 (as shown in
As can be seen in
In an exemplary application, the grinding apparatus 10 can resurface a belt having a width of 80 inches in about an hour. During this time, the grinding apparatus 10 removes approximately 0.5 to 1 mm of rubber during each pass. Each pass takes between 1 hour for a smaller rubber belt and 2 hours for a larger rubber belt to complete. The grinding wheel 15 spins at approximately 4000 rpm to 7000 rpm with 5000 rpm in one embodiment. Throughout the process, the grinding wheel 15 is tilted as it traverses from side to side. The tilting of the wheel, even if the tilt angle is only moderate, allows for elimination of visible and undesirable spiral line that would be formed by the trailing edge of the wheel if it did not include the curved lip 44 shown in
While the foregoing discussion has primarily considered endless rubber belts 2 used in a sanforizing process, the presently invented grinding apparatus 10 has applicability in other industries where rubber or urethane belts or rollers need resurfacing. For instance, paper mills and printing presses use rubber rollers that need resurfacing from time to time. The present invention can be used for these applications, and other applications are easily inferred.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the invention, they are by no means limiting, but are instead exemplary embodiments. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112(f) unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
The present methods can involve any or all of the steps or conditions discussed above in various combinations, as desired. Accordingly, it will be readily apparent to the skilled artisan that in some of the disclosed methods certain steps can be deleted or additional steps performed without affecting the viability of the methods.
As will be understood by one skilled in the art, for any and all purposes, particularly in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as “up to,” “at least,” “greater than,” “less than,” “more than” and the like include the number recited and refer to ranges which can be subsequently broken down into subranges as discussed above. In the same manner, all ratios disclosed herein also include all subratios falling within the broader ratio.
One skilled in the art will also readily recognize that where members are grouped together in a common manner, such as in a Markush group, the present invention encompasses not only the entire group listed as a whole, but each member of the group individually and all possible subgroups of the main group. Accordingly, for all purposes, the present invention encompasses not only the main group, but also the main group absent one or more of the group members. The present invention also envisages the explicit exclusion of one or more of any of the group members in the claimed invention.
Number | Name | Date | Kind |
---|---|---|---|
1169377 | Barnhart | Jan 1916 | A |
1429317 | Louis | Sep 1922 | A |
1689656 | Williams | Oct 1928 | A |
1968550 | Barnes | Jul 1934 | A |
2016590 | Bussing | Oct 1935 | A |
2579391 | Minarik et al. | Dec 1951 | A |
3165865 | Bousquet et al. | Jan 1965 | A |
3456394 | Welsh | Jul 1969 | A |
3653162 | Clark | Apr 1972 | A |
3775241 | Justus et al. | Nov 1973 | A |
3889424 | Buhayar et al. | Jun 1975 | A |
4206422 | Fein | Jun 1980 | A |
4322916 | Richmond | Apr 1982 | A |
4329192 | White, Jr. | May 1982 | A |
4575972 | Ohki et al. | Mar 1986 | A |
4941294 | Nagaki | Jul 1990 | A |
5214881 | Borchardt | Jun 1993 | A |
5386665 | Heim | Feb 1995 | A |
5414963 | Watanabe | May 1995 | A |
5597449 | Vestola et al. | Jan 1997 | A |
5738571 | Kitahama | Apr 1998 | A |
5853318 | Thom | Dec 1998 | A |
6213850 | Hashino | Apr 2001 | B1 |
6257964 | Helgren | Jul 2001 | B1 |
6616511 | Mori et al. | Sep 2003 | B2 |
6875080 | Gast, Jr. | Apr 2005 | B2 |
20080108283 | Poling, Sr. | May 2008 | A1 |
20080271384 | Puthanangady | Nov 2008 | A1 |
20120122374 | Honold et al. | May 2012 | A1 |
20130005226 | Watanabe | Jan 2013 | A1 |
Number | Date | Country |
---|---|---|
2038392 | Feb 1972 | DE |
Number | Date | Country | |
---|---|---|---|
20160375539 A1 | Dec 2016 | US |