Abstract:
A method and apparatus for finishing automotive wheels having a rotatable turret, a plurality of containers journaled on the turret capable of receiving media and capable of selective rotation independent of the turret, and fixtures in the containers that stably hold automotive wheels in said containers for selective reception of said media. The turrets rotate at speeds from 75 to 500 rpm&#39;s to produce sufficiently high forces on the wheels. The wheels are held in stable position by a fixture that comprises a plurality of plates fixed about the container shaft for stable engagement with the wheels. The plates may be attached with a flanged tube and angled at approximately 45 to 75 degrees from the plate. The invention also has means for reducing the pressure build up caused by the high rotational forces within the container.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to the field of automotive wheel finishing, and more particularly to a machine, process and fixture for surfacing, deburring, radiusing, descaling, polishing, abrading, or otherwise preparing automotive wheels for the application of many types of coating, plating, painting, and also to create a variety of final polishes or “finishes” for automotive wheels. 
     Machines for finishing small work pieces in a rotational barrel configuration are well known; however, a machine with the necessary fixturing and process for finishing automotive wheels through accelerated positive gravity induced burnishing is completely unknown in the automotive wheel manufacturing and finishing industries. In fact, manufacturers of automotive wheels currently use no type of a rotational barrel configuration technology to achieve the necessary pre-finishing preparation or to apply a variety of final “finishes” to automotive wheels. Finishing of large work pieces such as wheels requires a machine and fixturing system for holding the wheels to permit the wheels to receive high energy impacts from slurry mixtures without damaging the surface of the wheel in undesirable ways. Further, there does not exist a means for reducing the heat and pressure buildup in high energy machines running at high rotational speeds and generating large G forces. 
     Finishing small work pieces in a rotational barrel configuration is accomplished by use of slurry mixtures to create forces against the work pierces to grind down imperfections by utilizing gravitational forces to impart the force to the work piece in a desired fashion. Typically, the work pieces are placed loosely in a barrel and allowed to impact each other as well as the slurry mixture. Prior machines and methods for finishing small work pieces used hexagonal barrels mounted within a turret. The barrels typically moved in a counterclockwise fashion from the turret in such a way as to maintain a fixed position of the barrel with respect the horizon. This approach permitted the maximum impacting of the slurry mixture on the work pieces by agitating the system as the barrels rotated. 
     The deficiency of the prior technology is that there has existed no means or method for securing large work pieces such as automotive wheels in the proper position in a rotational barrel configuration machine to achieve an effective result. Further, no large barrels existed to hold automotive wheels and perform at high rotational speeds to achieve the desired results. Consequently, no machines utilizing a rotational barrel configuration have ever been developed with barrels of sufficient size to contain automotive wheels due, in part, to the lack of mechanisms for fixturing the wheels properly. Another problem solved by the instant invention when utilizing the large barrel sizes required to hold automotive wheels is a means for reducing the extreme heat and consequent pressure build-up inside the barrel which would result in unavoidable leakage detrimental to the process. Such means are integrated into the barrels and permit the entry of coolants to the system during rotation. 
     SUMMARY OF THE INVENTION 
     The primary object of the invention is to provide a viable method for machine pre-finishing and final finishing of automotive wheels. 
     Another object of the invention is to provide a method for high force pre-finishing and finishing of automotive wheels. 
     Another object of the invention is to allow automotive wheels going through the pre-finishing or final finishing process to become more controlled, thus making the automotive wheel more concentric. 
     Another object of the invention is to allow automotive wheels going through the pre-finishing or final finishing process to be prepared or finished throughout. The front, the back, the top, the bottom, the sides, inside crevasses, inside holes are radiused and polished creating a pre-finish or finish and otherwise eliminating sharp edges everywhere. 
     Another object of the invention is to provide a method for reduced time in pre-finishing or finishing automotive wheels. 
     Another object of the invention is to provide fixturing methods for automotive wheels which make utilization of the invention and related technology possible. 
     Another object of the invention is to provide a method to introduce a circulating coolant into the barrel while in motion to alleviate the extreme heat and consequent pressure build-up inside the barrel which would necessarily result from the G forces and friction generated to pre-finish or finish an object the size of an automotive wheel. 
     Other objects and advantages of the present invention will become apparent from the following descriptions, taken in connection with the accompanying drawings, wherein, by way of illustration and example, an embodiment of the present invention is disclosed. 
     In accordance with a preferred embodiment of the invention, there is disclosed a machine for finishing automotive wheels having a rotatable turret, a plurality of containers mounted on shafts capable of receiving media that are journaled on the turret and capable of selective rotation independent of the turret, and fixtures in said containers that stably hold automotive wheels in the containers for selective reception of the media. 
     In accordance with another preferred embodiment of the invention, there is disclosed a process for finishing automotive wheels comprising the steps of placing automotive wheels within a rotatable container, inserting slurry media to fill a portion of said container, rotating the container at approximately 75 to 500 revolutions per minute for a duration wherein the wheels are abraded to a relatively shiny appearance. 
     The drawings constitute a part of this specification and include exemplary embodiments to the invention, which may be embodied in various forms. It is to be understood that in some instances various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the invention showing a plurality of generally cylindrical container mounted on a turret. 
     FIG. 2 is a perspective exploded view of the cartridge and barrel for loading automotive wheels in the barrel. 
     FIG. 3 is a block flow chart of the operations that comprise the method for finishing automotive wheels. 
     FIG. 4 is a perspective view of the lower portion of a cartridge with mounting plates for the wheels. 
     FIG. 5 is a perspective view of the cartridge with soft cushioning supports on the lower portion of the wheels. 
     FIG. 6 is a perspective view of the mating upper cushioning supports for use in a cartridge. 
     FIG. 7 is a perspective view of the bottom half of the cartridge with wheels mounted on cushioning supports and fixed in place by tie straps over the top of the wheels. Also shown in FIG. 7A is a alternative support that may be placed under or over the wheels for stable engagement in the container. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner. 
     Turning first to FIG. 1, there is shown a perspective view of a preferred embodiment of the invention. Turrets  10  and  12  are mounted on shafts and driven by motors, not shown, that turn the turrets at high rates of rotational speed. Journaled and mounted on the turrets are a plurality of generally cylindrical barrels  14  which rotate at high speeds and may be operable by additional motors independently of the rotation of the turrets. The barrels may have a variety of internal configurations including hexagonal, octagonal and other shapes to create sufficient agitation of material within during rotation. Mounted within each barrel are workpieces, shown here as relatively large automotive wheels  18 . Wheels  18  are mounted generally perpendicularly to the barrels and are held in place through fixture means further described herein. The wheels may be mounted at an angle relative to the longitudinal axis of the barrel to facilitate the movement of media about the wheels. The barrels may also be lined in rubber or urethane and may be of any other generally cylindrical shape. 
     Upon activation by a motor to the turret, the barrels rotate to create high gravitational forces from rotational speeds of approximately 76-500 revolutions per minute. Barrels  14  are mounted by shaft and pulleys, not shown, to turrets  10  and  12  and may be rotated in a fixed position to counter rotation of the turrets or be separately powered by additional motors not shown. 
     The process for finishing the wheels is generally described below. Wheels  18  are fixtured inside barrels  14  in an appropriate orientation to the longitudinal axis of the barrels. Once the wheels are fixed in the barrel, abrasive media, water, or other materials are added to the barrels. The barrels are sealed to prevent any leakage. As more fully shown in FIG. 2, the barrels are composed of a cylindrical tube  30  having two ends with sealed caps  32  and  34  affixed to the ends of the tube. Caps  32  and  34  are affixed to the tube  30  by a plurality of fasteners  36  to completely seal and close the end of the tube. Caps  32  and  34  have shafts  38  protruding outward along the longitudinal axis to permit mounting of the barrel on the turrets. The tube  30  has displaced within it a cartridge  40  that is affixed with a plurality of separator panels  42 . The workpieces may be placed between the separator panels  42  to mount the workpieces and prevent lateral movement of the workpieces during rotation. Alternatively, the work pieces such as wheels may be mounted on a shaft going through the wheels or fixed in place through support cushions more fully shown in FIGS. 4,  5 ,  6  and  7 . Cartridge  40  has end caps  44  and  46  that are affixed to the cartridge. Cartridge  40  has additional panels  48  and  50  that close the support structure before placement within the barrel. After cartridge  40  is closed with panels  48  and  50  are placed in the tube  30 , door  54  may be latched with latches  56  to close and seal the tube. Once sealed, the tube is ready for high speed rotation and the finishing steps of the inventive method. 
     Due to the high pressure that may result form rotational speeds used in this process input means to the barrel are provided to introduce cooling fluids to the barrel to reduce temperature. The rotating shaft  38  is provided with a central boring hole  39  that runs the longitudinal length of the shaft to permit communication between the inside of the barrel and means for introduction of liquids to the barrel. The shaft  38  may be fitted with hardware, not shown, to allow a tube to run from the shaft to a pump or reservoir for the introduction of liquid into the barrel. Other approaches to entry in the container may be achieved via ports on end caps  32  and/or  34  so long as liquid is introduced in to the container and out of the container. Other input/output mechanisms may be designed so long as the amount of total media may be maintained at desirable is levels throughout the rotation process. As heat or pressure build up, sensors may detect when liquids should be introduced and the means for introducing those liquids is activated and liquid is pumped through the hole  39  into the barrel. Alternatively, the means for introducing liquid may be set to continuously introduce or intermittently introduce liquid over a time period that maintains the temperature or pressure at desired levels. The means for pumping liquids may be any conventional mechanism and are well known in the art. By permitting introduction of liquid during the rotational phase, the high pressure associated with this system may be alleviated. 
     Turning now to FIG. 3, there is shown the overall process for finishing automotive wheels. The first step in the process is a cutting process. FIG. 3 shows, among other things, the steps involved in the cutting process. Wheels are, mounted in the barrel at step  60 . Media and water is introduced at step  62  to the barrel. Any desired media or liquid may be introduced into the barrel depending on the desired finishing outcome. The barrel is locked and sealed at step  64  and prepared for high rotational speeds. The turrets are activated by motors that turn the barrels up to speeds of approximately 75 to 500 rotations per minute at step  66 . Step  66  shows a rotational speed of 500 rpm&#39;s, but anysuitable speed that creates the high energy forces to abrade the wheels may be used. Preferably these speeds range from approximately 75 to 500 rpm&#39;s. Once the proper cycle time is achieved, the rotation is terminated and the cutting process is completed at step  68 . Generally, as the speed of rotation is increased, the cycle time of the finishing process is generally reduced. As the speed of rotation is increased, the G forces on the wheels increase resulting in high pressure being applied to the wheels by the media and water. As the abrasives in the media impact the wheels, surface imperfections are abraded and the wheel obtains a shiny appearance. 
     The key factors affecting the degree of finishing are the amount and type of media and compound used, the speed of the turret, and the cycle time of the overall process. Different media used in the art are capable of achieving different finishes and cycle times depending on the desired results. The key to the inventive process is to stably mount the wheels in large cylinders and achieve high rotational speeds to create the force to drive the media against the wheels to abrade the surface in the desired amount. The media may be removed from the barrels and recycled for another process. 
     After the wheels are processed in the cutting process, they are prepared for the refinement process, if necessary, the finishing process or completion as shown in step  70 . If the refinement process is desired, the wheels are removed, cleaned and reinserted into the barrels and new media is introduced to the barrel at step  72 . Once the new media is introduced, the barrels are locked and sealed and the process proceeds as before at step  64 . During the refinement process step, the wheels are exposed to a milder abrasive media. After the refinement process is finished, the wheels may be removed and plated by conventional means if that look is desired. If plating is not desired, a final finishing or polishing step can be achieved with the inventive process and apparatus. 
     If the refinement process step was not desired at step  70 , the process proceeds to the polishing step at  74 . The polishing steps begin with preparation of the wheels by removing and cleaning them at step  74  and introducing dry media. The finishing or polishing step requires that the wheels be placed in the barrels as before but with a dry media such as crushed walnut shells, comcob, or wood shavings possibly with other additives to give the wheels a polished luster. Once the media is properly introduced and the wheels are in place, the process proceeds as before through steps  64  through  68 . In this process step, the rotating and loading is the same, but no water is used. High rotational speeds are used generating energy that heats the wheels to approximately 100 degrees F. Upon completion of these steps, the wheels are removed at step  76 . 
     FIG. 4 shows a fixturing for stably holding the wheels in the cartridge during the rotational process. Alternatively, the fixturing may be placed directly into the container and no cartridge used. So long as the container can be sealed and media introduced, the wheels may be placed directly into the container and stably fixed therein. Bottom half  90  of the cartridge is shown having an interior surface that is generally cylindrical with a plurality of flat faces making up a portion of the octagonal cartridge shape. A mounting shaft  99  runs the longitudinal length of the cartridge and is mounted on the inside end plates of the cartridge not shown. Shaft  99  is capable of receiving wheel mounting plates  91  via mounting tube  97  which is flanged onto plate  91 . The mounting tube  97  may be situated at a 90 degree angle to the plate  91 , but preferably is mounted at an angle of approximately 45 to 75 degrees relative to the plate. By angling the mounting plate to the shaft, the wheels  100  that are mounted to the plate receive added abrading action during the rotational process. The wheels  100  are mounted onto the plate  91  by conventional means such as a bolt  92  which is screwed into mounting holes  93  through holes that are standard on automotive wheels. The plate  91  may be configured to receive certain configurations of wheels or be universal by having several mounting holes  93  positioned to mate with the variety of mounting holes present in automotive wheels. The plate  91  may be secured to the shaft  99  by a set screw, not shown, or any other conventional means for inhibiting rotational movement of the plate relative to the shaft during the process. Other mechanisms for securing the plate may include a mating wing in the tube  97  that fits into a slot running down the longitudinal length of shaft  99 . Other securing means are well known in the art and need not be set forth here. The fixturing mechanism shown is designed to hold the wheels in a fixed position relative to the rotational movement of the barrels. The wheels are preferably mounted to the plate on their inside surface much the same way that an automotive wheels is mounted with one side affixed to the axle of the car. In this way, the surfaces that are most desirable for finishing are fully exposed to the media and will receive the maximum finishing from the process. 
     FIG. 5 shows an alternative mounting means that may be used in the invention. Bottom half  90  of cartridge is shown with a plurality of soft cushioning supports  102  displaced below each wheel which are part of a two part fixture. The supports  102  may be made of any suitable material that provides a stable support for the wheel and does not impart any excessive abrading to the wheel during the process. Molded urethane, rubber, plastic, and other synthetic materials may be used so long as the wheels are set into the cushion. Cushions  102  have mating upper cushions that are configured in such a way as to cover the top portion of the wheel when the cartridge is closed. The cushions  102  may be shaped on one side to match the outline of the inner surface of the cartridge, in this case, octagonally. The other surface of the cushion is shaped to fits the general contour of the wheel  100 . When both the top and bottom halves of the cushions are in place, the cartridge is closed and the wheels are properly positioned and held in place by friction. The cushions are designed so that upon closing the cartridge the wheels cannot substantially move long the longitudinal axis and are fixed in the rotational axis to prohibit movement of the wheels during the process. The wheels should preferably be spaced approximately 4 inches apart to permit maximum and optimal contact with the media. Although the cushions are shown covering substantially all of the surface of the portion of the wheel that mates with a tire, the cushions need only be large enough to hold the wheels in place. Thus, the cushions could be designed to cover less than the full circumference of the wheel and still hold the wheels in place sufficient for this process. Disadvantages of such an approach would be that certain portions on the wheels would be acted on by the media while other portions would not. However, there may be some applications where this is not a problem and thus a suitable fixturing means. 
     FIG. 6 shows the mating upper cushions that are placed on the upper side of the wheels after insertion into the cartridge. The upper cushions  108  are generally mirror images of the lower cushions having the same outer contour to fit the cartridge and the rounded inner surface to fit the wheels. 
     FIG. 7 shows another fixturing means for holding the wheels in place during the process. The lower half of the wheels is cushioned with a molded cushion support  102  as shown in FIG.  5 . However, rather than use a mating upper cushion, the upper portion of the wheel is held into place by a tie strap  112  that is affixed to the cushioning support or to the side of the cartridge. Tie strap  112  may be of any suitable material such as plastic, metal, or other cord so long as it holds the wheels in place during the process and does not permit excessive movement of the wheel. Such a strap would permit the media to act on a portion of the wheel, but as previously noted this may be acceptable in certain circumstances. 
     Other fixturing means may be accomplished by predetermined mounting hardware on the inside of the cartridge pieces or the container or mounting pieces that are placed into the cartridge or the container as the wheels are loaded. Such a mechanism could be configured of support structures having several legs for supporting the wheel in a position away from the outer edges of the cartridge but doing so in a stable manner that permits the media to reach most portions of the wheel that require finishing. A suitable mounting support  114  is shown in FIG.  7 A. Such a support could be placed into the cartridge upon which the wheel is placed or be fixed to the inside wall of the cartridge. Then a mating support of similar design could be placed on the top of the wheel or fixed to the top inside of the cartridge before dosing the cartridge. Depending on the size of the wheel and the cartridge, the support pair may be configured to provide a tight fit within the container to prevent lateral and rotational movement of the wheel during the rotational process. This would provide stable support to the wheel during rotation and permit the media to reach the desired portions of the wheel. 
     While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.