Abstract:
A system and method for finishing a series of golf balls is disclosed herein. The system automatically transfers each of the golf balls from station to station on the system. The system has at least one coating station that has at least one spray gun that moves in relation to a golf ball being conveyed through the coating station. The spray gun moves in a track extending from a position below the golf ball to a position above the golf ball. The system has a transfer means that includes a series of transport pucks. Each transport puck has a plurality of shafts with spindles attached to the top of each of the shafts. Each spindle holds a golf ball for processing through the system. The spindles are rotated at relatively high rates during the coating process. In order to reduce tip marks on the finished golf ball, the golf balls are transferred from each spindle utilizing a high pressure gas. The system may be used to coat each golf ball with a basecoat, an indicia and a topcoat.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     Not Applicable 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a system for painting golf balls. More specifically, the present invention relates to an automated system for applying a base coat, a logo indicia and a clear coat to a golf ball. 
     2. Description of the Related Art 
     Golf balls are painted to enhance durability and improve the appearance thereof. Most golf balls are painted white with a base coat, then printed with a logo indicia and covered with a clear coat. Such a procedure has been used in the golf industry for many years. 
     In the prior art, a chain-on-edge conveyor was used to transport the unfinished golf balls through the painting system. This led to high maintenance due to the length of the chain, the need for continuous lubrication, and inefficient chain movement necessitated by the serpentine layout of the conveyor. These prior art systems would also use pick-and-place robotics for transfer of the golf balls from one station to another thus leading to numerous pick and tray marks on the golf balls during the process. Such marks would detract from the appearance of the golf ball, sometimes rendering the golf ball unsuitable for sale, especially higher priced premium golf balls. 
     Prior art processes also use inefficient in-line curing ovens. The work-in-process inventory also builds up during the process due to the use of many collection hoppers and gondolas. The prior art systems also utilize ineffective cleaning procedures to maintain the equipment in working order. 
     Further, the prior art systems convey a golf ball past a series of stationary spray guns resulting in inefficient coating applications. The prior art systems also result in the pooling of paint or other coatings in the dimples which deters from the aerodynamic performance of the golf ball. Current dimple patterns have shallower dimples and require a specific coating thickness to achieve better aerodynamic performance of the golf ball. 
     Thus, there is a substantial need for a finishing system that can overcome the problems associated with the prior art systems. 
     BRIEF SUMMARY OF THE INVENTION 
     One aspect of the present invention is a method for finishing a series of golf balls. The method includes transferring the golf balls to a coating station that has a booth with a spray gun assembly within the booth. The spray gun assembly has at least one spray gun. The method also includes coating each of the golf balls with a coating through movement of the spray gun about each of the golf balls. The method also includes transferring each of the coated golf balls from the coating station to a curing station and curing each of the coated golf balls at the curing station. 
     Another aspect of the present invention is a system for finishing a series of golf balls having an unfinished surface. The system includes a means for transferring each of the golf balls throughout the system, at least one coating station and a means for curing the coated golf balls. The coating station is disposed along the transferring means. The coating station has a booth, a conveyance line for transferring each of the golf balls through the booth, and at least one coating applicator for coating each of the golf balls within the booth. The one coating applicator is capable of movement transverse to the conveyance line. The curing means is disposed subsequent to the coating station. 
     Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a schematic view of the golf ball painting system of the present invention. 
     FIG. 2 is a perspective view of a golf ball finished on the system of the present invention. 
     FIG. 3 is a isolated side view of a transfer means of the system of the present invention. 
     FIG. 4 is an isolated side view of a transport puck of the system of the present invention. 
     FIG. 5 is a top plan view of the transport puck of FIG.  4 . 
     FIG. 6 is an isolated top plan view of a spindle of the system of the present invention. 
     FIG. 7 is a side plan view of the spindle of FIG.  6 . 
     FIG. 8 is an isolated cross-sectional view of a transport puck of the system of the present invention. 
     FIG. 9 is an isolated view of the walking beam conveyance system for the coating station of the system of the present invention. 
     FIG. 10 is a top plan view of FIG.  9 . 
     FIG. 11 is a side plan view of FIG.  9 . 
     FIG. 12 is an isolated side view of the coating station of the system. 
     FIG. 13 is a front view of FIG.  12 . 
     FIG. 14 is an isolated side view of the spray gun mechanism of the system. 
     FIG. 15 is a top plan view of FIG.  14 . 
     FIG. 17 is an isolated perspective view of a transfer mechanism of the system. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in FIG. 1, a golf ball painting system is generally designated  20 . The system  20  is completely automatic thereby allowing for the finishing, or painting, of golf balls without operator involvement in the process. The system  20  includes a transfer means  22  for transferring a plurality of golf balls  25  from and to each of the stations of the system  20 . The transfer means may be a conveyor system that transfers each of the golf balls  25  individually, or a conveyance system that transfers the golf balls  25  in groups throughout the system. The golf balls  25  are transferred from other processes to a collection hopper  23  for finishing of the golf ball  25  on the system  20 . The other processes may include core forming processes and cover forming processes. The cover may be composed of a thermoplastic material such as an ionomer material or a thermoset material such as a polyurethane material. Prior to placement in the collection hopper  23 , the golf balls  25  may be fed through a vibratory wash to remove any dust particles or other foreign matter from the surface of each of the golf balls  25 . 
     The collection hopper  23  automatically loads the golf balls  25  onto a conveyor for transfer through a surface treatment station  24 . The surface treatment station  24  increases the surface tension of the exterior of each of the golf balls  25 , and chemically alters the surface material of each of the golf balls  25 . The higher surface tension on the exterior of each of the golf balls  25  assures a uniform flow of paint, thereby eliminating or at least reducing pooling of paint in the dimples of each of the golf balls  25 . Preferably, the surface treatment station is a plasma treatment. However, alternative surface treatments include flame ionization, flame reduction/oxidation, corona discharge, and the like. The plasma treatment process consists of bombardment of air with a high-energy electrical plasma arc that creates ionized gases that contain ions, electrons, radicals, excited molecules and atoms. The ionized gases react with the surface of each golf ball  25  to cause polymer chain scission, ablation, cross-linking and oxidation to a depth ranging from fifty to five-hundred Angstroms from the surface of the golf ball  25 . Essentially highly reactive and potential bonding sites are created on the surface of the golf ball  25  in order to increase adhesion of the basecoat or primer. The plasma treatment process is performed at ambient air temperatures and at standard atmospheric conditions (25° C. and 1-atm.) as opposed to high temperature and vacuum conditions associated with conventional plasma treatment devices. The residence time in the plasma treatment station  24  may be regulated according to the chemistry requirements of the surface material. Such a plasma treatment system is described in Leach et al., U.S. Pat. No. 3,428,801, which is hereby incorporated by reference in its entirety. 
     After the surface treatment station  24 , each of the golf balls  25  is transported at a first transfer station  26  to the transfer means  22  for conveyance to the next station. A tamping device  27 , not shown, secures each golf ball  25  on the transfer means. The tamping device will be described in greater detail below. Once on the transfer means  22 , each of the golf balls  25  is conveyed to a first coating station  28 . At the first coating station  28 , a basecoat is applied to each of the plasma treated golf balls  25 . The basecoat is typically a two-component polyurethane white paint or an ultraviolet light curable paint. One example of a two-component polyurethane white paint is based on DESMODUR® polyol and urethane resins available from the Bayer Corporation of Pittsburgh, Pennsylvania. The first coating station  28  will be described in greater detail below. After the first coat or basecoat is applied to each of the golf balls  25 , the golf balls  25  are conveyed by the transfer means  22  to the first curing station  30 . In a preferred embodiment, the first curing station  30  is a typical convection heating oven for curing the basecoat that was previously applied to each of the golf balls  25 . Alternatively, the first curing station  30  may be an ultraviolet light curing chamber. The first curing station  30  cures the golf balls  25  for application of an indicia thereon at the next station. 
     After curing, the golf balls  25  are conveyed on the transfer means  22  to the second transfer station  32 . Once the golf balls  25  are unloaded at the second transfer station  32 , the individual transport units, which will be described in greater detail below, may be conveyed to a changing station  34 , which will be described in greater detail below. From the second transfer station  32 , each of the golf balls  25  is transferred to an indicia application station  36  for application of an indicia onto each of the golf balls  25 . In a preferred embodiment, the indicia application station  36  is a pad printing station. As shown in FIG. 2, each of the golf balls  25  may be marked with an indicia  37  using an ink. A preferred ink is an ultraviolet light curable ink such as UVA available from Trans Tech of Chicago, Ill. From the indicia application station  36 , each of the golf balls  25  is conveyed to an indicia curing station  38 . In a preferred embodiment, the indicia curing station  38  is an ultraviolet light curing station. 
     From the indicia curing station  38 , each of the golf balls  25  is conveyed to a third transfer station  40 . At the third transfer station  40 , each of the golf balls  25  is transferred to the transfer means  22  for conveyance to the second coating station  42 . In a preferred embodiment, the second coating station  42  is a topcoat application station. The topcoat is typically a two-component polyurethane coating that may be based on DESMODUR® polyols and urethane prepolymers available from the Bayer Corporation of Pittsburgh, Pennsylvania. Alternatively, the topcoat may be an ultraviolet light curable clearcoat. The second coating station  28  will be described in greater detail below. After the second coat or topcoat is applied to each of the golf balls  25 , the golf balls  25  are conveyed by the transfer means  22  to a second curing station  44 . In a preferred embodiment, the second curing station  44  is a typical convection heating oven for curing the topcoat that was previously applied to each of the golf balls  25 . Alternatively, the second curing station  44  may be an ultraviolet light curing chamber. After curing, each of the golf balls  25  is conveyed to a fourth transfer station  46 . At the fourth transfer station  46 , the golf balls  25  are transferred from the system  20  for packaging thereof. Once the golf balls  25  are unloaded at the fourth transfer station  46 , the individual transport units may be conveyed to a second changing station  48 , which will be described in greater detail below. 
     As illustrated in FIG. 3, the golf balls  25  are transferred along the system  20  by a transfer means  22 . In a preferred embodiment, the transfer means  22  is an SKF conveyor  50  utilizing a plurality of transport pucks  52  to move groups of the golf balls  25  along the system  20 . The speed of the SKF conveyor  50  is controllable for proper movement timing of the transport pucks  52  between stations. The SKF conveyor  50  is typically not enclosed and thus the transport pucks  52  are open to the environment during movement between stations. This open conveyance allows for easier maintenance of the transfer means  22 . Further, the SKF conveyor  50  is modular, and thus can be structured to accommodate adjustments in the length and placement of the system  20 . 
     As shown in FIGS. 4-8, each transport puck  52  has a plurality of golf ball holding fixtures  54  and a base  56 . In a preferred embodiment, each transport puck  52  has four fixtures  54 . The fixtures  54  are disposed on the base  56 , and each fixture  54  may be removable or permanently attached to the base  56 . Each base  56  is disposed on the SKF conveyor  50  for movement about the system  20 . Each of the fixtures  54  has a shaft  58  topped with a spindle  60 . Each of the spindles  60  rotates about an imaginary fixed vertical axis  62  through the center of each corresponding shaft  58 . Each spindle  60  has a plurality of prongs  64  for holding a golf ball  25  as the golf ball  25  is processed through the system  20 , and each spindle  60  is removable form each corresponding shaft  58 . The prongs  64  project upward from a spindle base  66 , and are shaped to accommodate a golf ball  25 . In a preferred embodiment, each of the spindles  60 , including the prongs  64  and the base  66 , is composed of a glass-filled nylon material. 
     As shown in FIGS. 6 and 7, each of the spindles  60  holds a golf ball  25 ′ (indicated by dashed lines) at a tip  68  of each of the plurality of prongs  64 . The tips  68  engage the golf ball  25 ′ halfway between a pole of the golf ball  25 ′ and the equator of the golf ball  25 ′. It is preferable that the contact area with the golf ball  25  be a minimum to avoid tip marks that deter from the appearance of the golf ball  25 . Further, during each cycle of the system  20 , each spindle  60  accumulates an amount of paint, basecoat or topcoat, that will eventually lead to tip marks or in some other manner interfere with the painting of a golf ball  25  on the system  20 . Thus, it is necessary to remove each spindle  60  for cleaning and maintenance after a predetermined number of cycles on the system  20 . Removal of the spindles  60  is performed at each of the spindle changing stations  34  and  48  on the system  20 . Each transport puck  52  has a unique binary code that is transmitted to a signal receiver at a designated spindle changing station  34  or  48 . If the transport puck  52  has been through the portion of the system the predetermined cycles, then the transport puck  52  is off-loaded from the transfer means  22  at the designated spindle changing station  34  or  48  for removal and replacement of its spindles  60 . After replacement of its spindles  60 , the transport puck  52  is on-loaded to the transport means  22  to cycle through the system  20  again. 
     Referring again to FIGS. 6 and 7, in a preferred embodiment each spindle  60  has three prongs  64  equally spaced from each other. Each prong  64  extends upward and outward from the base  66  in an arc, then upward at approximately a ninety degree angle, and finally upward and inward at approximately a thirty degree angle relative to the equator of the golf ball  25 ′. However, those skilled in the pertinent art will recognize that the number of prongs  64  may vary and the structure of each prong may vary without departing from the scope and spirit of the present invention. A United States Golf Association approved golf ball  25  has a diameter of at least 1.680 inches. In the preferred embodiment, the prongs  64  form a phantom diameter  70  (indicated by dashed lines) that is 1.437 inches in diameter. In the preferred embodiment, the height of each spindle  60 , from the bottom of the base  66  to the tip  68 , is 2.111 inches. Each of the spindles  60  engage the corresponding shaft  58  through mating of a pin  74  projecting from the top of the shaft  58  with a cavity  72  located in the bottom of the base  66 . The spindle  60  is also rotated through this mechanism. 
     Additionally, the tamping device  27  secures each of the golf balls  25  within the spindles  60  at precise levels to hold the golf balls tightly during the processing. The tamping device  27  eliminates or at least reduces the movement of the golf ball  25  during processing thereby resulting in the elimination or at least reduction of tip marks on the golf ball  25 . 
     In a preferred embodiment of the system  20 , there are two coating applications, a basecoat application and a topcoat application. However, those skilled in the pertinent art will recognize that the system  20  may have only one coating application or more than two coating applications without departing from the scope and spirit of the present invention. The transfer means  24  has a first track that operates in relation to the first coating application and a second track that operates in relation to the second coating application. The printing of the indicia will have a integral transfer means. In the preferred embodiment, the first coating station  28  and the second coating station  42  are the same except for the coating applied to each of the golf balls  25 . Thus, the description of the first coating station  28  will apply equally to the second coating station. 
     As shown in FIGS. 9-11, the golf balls  25  are conveyed through the first coating station  28  while disposed on transport pucks  52 . The transfer means  24  conveys each transport puck  52  to a walking beam conveyance system  72  that is an integral component of the first coating station  28 . The waling beam conveyance system  72  conveys each of the transport pucks through the first coating station  28 , and assists in the rotation of each of the spindles  60 . Each spindle  60  rotates at a predetermined rate through the first coating station  28  in order to effectuate the coating of the entire golf ball  25 . In a preferred embodiment, each golf ball  25  rotates at a speed of two-hundred rotations per minute as it is coated with the basecoat or topcoat. However, the rotation speed may vary from fifty to five-hundred rotations per minute while the golf ball  25  is still maintained on the spindle  60 . 
     FIGS. 12-15 illustrate the servo-driven spray gun motion control mechanism  74  of the first coating station  28 . The spray gun mechanism  74  is disposed within an enclosed housing  76  of the first coating station  28 , and which lies on a base  78 . The enclosed housing  76  has a viewing window  82  for monitoring the coating application of each golf ball  25 . The spray gun mechanism  74  has an arm mechanism  84  that is driven by a drive mechanism  86 , with both the drive mechanism  86  and the arm mechanism  84  mounted on a frame  88 . The drive mechanism  86  moves the arm mechanism  84  about the golf balls  25  as the golf balls  25  are conveyed through the enclosed housing  76 . In a preferred embodiment, the arm mechanism  84  moves in an arc from below the golf balls  25  to a position above the golf balls  25 . As mentioned previously, the golf balls  25  are rotated at a predetermined rate as the arm mechanism  84  moves about the golf balls  25 . At the end of the arm mechanism is the spray gun base that holds a plurality of spray guns  92 . The spray guns  92  apply the coating to each of the golf balls  25  as each golf ball  25  is rotated in the spindle  60 . The shaft  58  ensures that each golf ball  25  is disposed at a sufficient height above the walking beam conveyance system  72  to ensure proper application of the coating on the lower portion of each golf ball  25 . The range and speed of the arm mechanism  84  may be adjusted and controlled to maximize transfer efficiency of the coating to the golf ball  25 , and to produce an evenly coated golf ball  25  to validate aerodynamic expectations for a particular golf ball dimple pattern. The motion of the arm mechanism  84  may be in an arc ranging from twenty degrees to one-hundred fifty degrees. The spray pattern and the arc-like motion require that the speed of the movement of the arm mechanism  84  vary in order to have proper application of the coating. Thus, the arm mechanism  84  is slower about the equatorial region of the golf balls  25  as opposed to the polar regions of the golf balls  25  to assure precise uniformity and thickness of the coating. As shown in FIGS. 14 and 15, the arm mechanism  84  has a plurality of horizontal links  94   a  and  94   b  and a plurality of vertical links  96   a  and  96   b  that hold and assist in maneuvering the spray gun base  90 . The links  94  and  96  allow for the arc-like motion of the spray gun base from below the golf balls  25  to above the golf balls  25 . The drive mechanism  86  for the arm  84  may be an AC motor, a servomotor, a robot driver, or the like. 
     FIG. 16 is an exploded view of a spray gun  92  utilized in the present invention. The spray gun  92  has a body  100 , a clamp  102 , an air cap  104 , a liquid injector  106  having a passageway, a rear insert  108 , a front insert  110 , a first O-ring  112  and a second  0 -ring  114 . This construction of each spray gun  92  allows for proper application of the coating to the golf ball  25 . The diameter of the passageway of the injector  106  is approximately 0.035 inches. The injector  106  produces a small orifice outflow having a conical spray pattern with a tip atomization pressure of less than ten pounds per square inch. The transfer efficiencies of the spray gun  92  of the present invention are as high as sixty percent as compared to fifteen percent for coating systems of the prior art. The coating fluid is delivered to each spray gun  92  by a corresponding tube, not shown, utilizing gear pumps that precisely regulate the volume of fluid through each spray gun  92 . The spray gun mechanism  74  has a gun-purge and tip-clean trough to maintain clear passages and clean nozzles for application of the coating to the golf balls  25 . A face spray array cleans the gun nozzle tips and flushes the inner chamber of the guns at regularly programmed intervals. The purge trough contains twelve spray jets that deliver a cleansing solvent for cleaning of the spray guns  92   
     FIG. 17 is a perspective view of a transfer mechanism  116  that is the main component of each of the transfer stations  26  and  40  of the system  20  of the present invention. The transfer mechanism  116  has a central channel  118  for receiving the golf balls from the transfer means  22  or from a station such as the plasma treatment station  24 . The central channel is angled to utilize gravity to move the golf balls  25  to a plurality of chutes  120   a-d . The chutes  120   a-d  distribute the golf balls  25  into transfer groups of a set number for processing or for placement on the transport pucks  52 . During off-loading from the transport pucks  52 , the system  20  utilizes high pressure de-ionized air to gently remove each golf ball  25  from each corresponding spindle  60  for further processing on the system  20  or for packaging. 
     From the foregoing it is believed that those skilled in the pertinent art will recognize the meritorious advancement of this invention and will readily understand that while the present invention has been described in association with a preferred embodiment thereof, and other embodiments illustrated in the accompanying drawings, numerous changes, modifications and substitutions of equivalents may be made therein without departing from the spirit and scope of this invention which is intended to be unlimited by the foregoing except as may appear in the following appended claims. Therefore, the embodiments of the invention in which an exclusive property or privilege is claimed are defined in the following appended claims.