Abstract:
An automated flash/overflow removal system for the manufacturing of golf balls, including a gripping assembly mounted on a motion system. The gripping assembly includes a plurality of gripping members capable of clamping and releasing the flash/overflow from a golf ball mold portion.

Description:
FIELD OF THE INVENTION 
   This invention relates generally to the method and apparatus of golf ball production and, more particularly, to the removal of flash or overflow in molding a golf ball portion. The golf ball portion may be a golf ball core, an outer core layer, a cover, an intermediate layer between the core and the cover, an inner cover layer, or an outer cover layer. 
   BACKGROUND OF THE INVENTION 
   The United States Golf Association (“USGA”) provides five (5) regulations to keep golf balls consistent. Specifically, the golf ball must weight no more than 1.62 ounces and measure no less than 1.68 inches in diameter. The initial velocity of the ball as test on a USGA machine at a set club head speed must not exceed 255 ft/sec. The overall distance of the ball as tested with a USGA specified driver at 160 ft/sec and a 10 degree launch angle must not exceed 296.8 yards. And the ball must pass a USGA administered symmetry test. Within the confines of these regulations, other performance characteristics of the ball, including distance, durability, feel, spin, sound, etc., may be modified through alterations in material compositions, constructions, diameters and/or thickness, and surface configurations of various portions of the ball, such as the core(s), cover(s), and intermediate layer(s) therebetween. Other physical, mechanical, chemical, and/or optical properties of the portions, including color stability, compression, density, flexural modulus, gas or vapor permeability, hardness, stiffness, tear resistance, weight, etc., may also be affected by these alterations. 
   Various portions of a golf ball, including cores, centers, outer core layers, intermediate layers, inner cover layers, and outer cover layers, are usually formed through a molding method. Suitable molding methods known to one of ordinary skill in the art include, but are not limited to, compression molding, injection molding, reaction injection molding (“RIM”), casting, or combinations thereof. A process common to these molding methods is the removal of flash or overflow attached to the molded golf ball portion that is generated during the molding process. Due to the random nature of the flash/overflow formation, and the fact that the flash/overflow volume of a golf ball mold is not filled completely to ensure quality and consistency of the molded portion, the shape and dimension of the flash/overflow are irregular and inconsistent. This in turn makes it difficult to remove the flash/overflow automatically. Conventional method of removing the flash/overflow is manual (by hand), which requires direct labor input, increases manufacturing cost, and reduces production rate. Manual removal of the flash/overflow may also inadvertently contaminate the surface of the molded golf ball portion. For example, the loose fragments of the flash/overflow may come in contact with the molded golf ball portion, adhering to or cured to the portion. Such contamination adversely affects the quality of the molded golf ball portion and the final product formed therefrom. 
   Therefore, a need exists for an automated method and apparatus to remove the flash/overflow from the molded golf ball portions effectively, efficiently, and reliably. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to a method and apparatus for automated removal of flash/overflow from a mold portion during golf ball production. The flash/overflow is integrally attached to a molded golf ball or precursor thereof and situated on a mold portion immediately after molding. The molded golf ball or precursor thereof is removed first the flash/overflow is retained on the mold portion. This is accomplished by positioning a suction cup over the molded golf ball or precursor thereof and applying a vacuum suction to the suction cup. The molded object is picked up, but the flash/overflow is retained, thereby separated from the molded object. The suction cup holding the molded object is moved to a predetermined position, where the vacuum is removed, and the molded golf ball or precursor thereof falls under gravity into a container for collection. 
   To remove the retained flash/overflow from the mold portion, a gripping assembly is used, which includes at least one gripping member capable of clamping and releasing the flash/overflow. Preferably, the gripping assembly has between 2 to about 20 gripping members arranged in a one-dimensional or two-dimensional array. The gripping members are operated independently or synchronously. More preferably, the gripping assembly comprises 4 co-planar and synchronized gripping members arranged in a 2×2 array. The gripping assembly is mounted on a motion system, which moves the gripping assembly pneumatically from a starting position to an alignment position directly over the mold portion, and then lowers the gripping assembly towards the mold portion for docking. The motion system may involve one-dimensional motions, two-dimensional motions, three dimensional motions, linear motions, rotational motions, or combinations thereof. 
   An alignment portion at the end of the gripping member is lowered into a cavity of the mold portion so that a brink of the gripping member is pressed against a rim of the mold portion. At the same time, the gripping member is loaded with a compressed energy through a spring mechanism for later ejection of the flash/overflow. The alignment portion has a substantially spherical side surface and a substantially flat bottom surface, and fits snuggly into the cup-shaped mold cavity. Preferably, the brink and the rim are both substantially annular, and the brink is no wider than the rim. With such a construction, the gripping member can easily align and dock to the mold portion. 
   The gripping member also has a center clamping portion positioned inside the flash/overflow, and a plurality of perimeter clamping portions positioned about the center clamping portion and outside the flash/overflow. The center clamping portion is substantially tapered, having an outward surface with a convex curvature facing the perimeter clamping portions, to facilitate the discharge of the flash/overflow from the gripping member. The convex curvature is preferably inverted frustoconical. The plurality of perimeter clamping portions can be between 2 to 10 fingers disposed substantially uniformly about the center clamping portion. Each of the plurality of perimeter clamping portions has an inward surface with a concave curvature facing the center clamping portion. The concave curvature of the perimeter clamping portions is preferably flatter than or equal to the convex curvature of the center clamping portion. The perimeter clamping portions are moved inward pneumatically in a concentric and synchronous manner, to clamp the flash/overflow securely between the center clamping portion and the perimeter clamping portions. 
   The gripping assembly with the flash/overflow secured by the gripper members therein is moved using the same motion system to disengage from the mold portion and moved away therefrom to an ejection position, which can be the same as the starting position. The plurality of perimeter clamping portions is disengaged from the flash/overflow by moving outward concentrically, releasing the compressed spring mechanism which ejects the flash/overflow off the gripping member. The expelled flash/overflow then falls under gravity into a container for collection. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a prospective view of an automated flash/overflow removal apparatus; 
       FIG. 2  is a front view of the apparatus of  FIG. 1 ; 
       FIG. 3  is an explosive view of the components incorporated in the apparatus of  FIG. 1 ; 
       FIG. 4  is a front view of a gripping assembly; 
       FIG. 5  is a bottom view of the gripping assembly of  FIG. 4 ; 
       FIG. 6  is a collection of aspect views of a core post; 
       FIG. 7  is a collection of aspect views of a finger; 
       FIG. 8  is a collection of aspect views of another finger; 
       FIG. 9  is a cross-sectional view of a gripping member sitting on a bottom mold portion to retrieve the flash/overflow; 
       FIG. 10  is a prospective view of a gripping member engaged with the flash/overflow; 
       FIG. 11  is a prospective view of a gripping member expelling the flash/overflow; and 
       FIG. 12  is a flow chart of removal of molded golf ball or precursor thereof from the molded portion prior to removal of flash/overflow. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Referring now to the figures, a discussion of the above features with respect to exemplary embodiments is provided below. It should be understood that such embodiments are for illustrative purposes, and should not be construed as limiting the scope of the invention. 
     FIGS. 1–3  illustrate an example of the automated flash/overflow removal system  10  (“AFORS”) of the present invention, comprising a mechanical joint rodless cylinder  20 , a compact guided cylinder  30 , and a gripping assembly  50 . Rodless cylinder  20  is connected to a first pressure source (not shown) such as a gas tank or cylinder via inlet/outlet  24 , which provides pneumatic power to drive a piston table  22  of rodless cylinder  20  in between a pair of end stops  26 . Piston table  22  is connected to the internal piston of rodless cylinder  20  by means of a magnetic or mechanical coupling system, and serves as an external carriage. Positioning of piston table  22  along rodless cylinder  20  is controlled by two sensors embedded within rodless cylinder  20 . A set of anchoring plates  28  is used to mount rodless cylinder  20  directly onto a golf ball production line (not shown here). 
   Guided cylinder  30  is mounted onto table  22  of rodless cylinder  20  at a stationary end  36  via an anchoring member  32 . Gripping assembly  50  is mounted onto a mobile (extendable) end  38  of guided cylinder  30  via a set of anchoring plates  40 . Guided cylinder  30  is connected to a second pressure source (not shown) such as a gas tank or cylinder via inlet/outlet  34 , which provides pneumatic power to guided cylinder  30  and allows mobile end  38  to extend out of and retract into guided cylinder  30 . Guided cylinder  30  utilizes a guide rod mounted in parallel with the piston rod to provide stable, non-rotating, high side load performance. The vertical positioning of mobile end  38  is controlled by a pair of sensors embedded within guided cylinder  30 . Guided cylinder  30  may be replaced by any other cylinders or actuators having similar capabilities, may be operated using an electronic motor or other systems, and may be powered by mechanical, electrical, hydraulic, or other means. 
   The combination of rodless cylinder  20  and guided cylinder  30  provides the attached gripping assembly  50  with two-dimensional maneuverability. One of ordinary skill in the art would understand that linear rodless cylinder  20 , guided cylinder  30 , or combination of the two may be substituted with other means or automated devices having at least one degree of freedom (at least 1-axis control) and being capable of spatial transport. Alternative devices suitable for the AFORS of the present invention may be driven by pneumatic power, hydraulic power, magnetic power, mechanical power, or combinations thereof, and include, but are not limited to, robotic arms, crane-like devices comprising rotary actuators, various cylinders, rotators, sliders, or actuators (linear, rotary, or multi-motion), or combinations thereof capable of one-dimensional, two-dimensional, or three-dimensional movements. Preferable rodless cylinders  20  and guided cylinders  30  are supplied by SMC Corporation of America in Indianapolis, Ind. Other comparable cylinders or alternatives are also commercially available to the skilled in the art. 
   Gripping assembly  50  comprises a plurality of gripping members  60 , arranged in a format so that each gripping member  60  corresponds to a bottom mold cavity  110  in a bottom mold platen  100 . Referring to  FIGS. 4 and 5 , each gripping member  60  comprises a substantially cylindrical gripper body  62  having three jaws  68  integrated therein at a flat end, the jaws  68  being spaced substantially equilaterally; a spring actuated part ejector  66  coupled to gripper body  62  covering partially the same flat end without overlapping with jaws  68 ; two fingers  80  and a third finger  90  each mounted on a jaw  68 ; a core post  70  mounted on ejector  66  opposite to gripper body  62 ; and a pair of inlet/outlet  64  fashioned on the curved side of gripper body  62 . This concentric stacking of gripper body  62 , ejector  66 , and core post  70  allows the spring(s) of ejector  66  to be compressed (pre-loaded) when core post  70  moves toward gripper body  62 , and extended (un-loaded) when core post  70  moves away from gripper body  62 . Fingers  80  and  90  are mounted such that they are adjacent to the perimeter of core post  70  and are substantially equilateral as well. Designated pair of inlet/outlet  64  is connected to a third pressure source (not shown) such as a gas tank or cylinder to provide pneumatic power to jaws  68  and allow parallel and synchronous operation of fingers  80  and  90  as described below. Materials for components of gripping member  60  are preferably metals, treated metals, metal alloys, ceramics, or durable plastics. Parallel grippers encompassing a gripper body  62  made of hardcoated aluminum with three jaws  68  made of hardened steel and a part ejector  66  made of steel are supplied by PHD, Inc. of Fort Wayne, Ind. Other comparable grippers or alternatives are also commercially available and known to the skilled in the art. 
   Referring to  FIGS. 6–8 , the spatial configurations of core post  70  and fingers  80  and  90  are illustrated. Core post  70 , as shown in  FIG. 6 , has a gripping portion  71  and an alignment portion  75 . Gripping portion  71  is generally tapered downward, preferably inverted frustoconical in shape, having three recesses  72  on its upper periphery to accommodate portions of fingers  80  and  90 . A concave side portion  73  is fashioned to accommodate a neighboring gripping member  60 . A lower outer surface  74  is substantially tapered downward, preferably inverted frustoconical, and is in contact with a flash/overflow  200  during flash/overflow retrieval and removal. Alignment portion  75  is concentrically recessed from the bottom perimeter of gripping portion  71 , leaving a brink  76  about alignment portion  75 . Brink  76  is fashioned to be complementary to top rim  112  of bottom mold portion  110 , as described below. An outer surface  78  of alignment portion  75  is fashioned to have a spherical contour that fits snuggly with an upper inner wall  116  of bottom mold cavity  110 . 
   Fingers  80 , as shown in  FIG. 7 , each have a tip portion  82  and a body portion  84 . Body portion  84  is shaped to fit loosely in one of the recesses  72  of core post  70 , so that finger  80  can move radially with respect to a longitudinal axis C of gripping member  60  (see  FIG. 9 ). Tip portion  82  has a flat outer surface  86  and a substantially inverted frustoconical concave inner surface  88 . A first radius of inner surface  88  can be less than a second radius of lower outer surface  74  of core post  70  at equal altitude, but preferably greater than or equal the second radius. Most preferably, the curvature of inner surface  88  is complementary to or slightly less arched than lower outer surface  74  of core post  70 . Finger  90 , as shown in  FIG. 8 , has a tip portion  92  and a body portion  94 . Body portion  94  is shaped to fit loosely in one of the recesses  72  of core post  70 , so that finger  90  can move radially with respect to axis C (see  FIG. 9 ). Tip portion  92  has a substantially inverted frustoconical convex outer surface  96  and a substantially inverted frustoconical concave inner surface  98 . A first radius of inner surface  98  can be less than a second radius of lower outer surface  74  of core post  70  at equal altitude, but preferably greater than or equal the second radius. Most preferably, the curvature of inner surface  98  is complementary to or slightly less arched than lower outer surface  74  of core post  70 . The curvature of outer surface  96  is preferably in parallel with that of inner surface  98 . Fingers  80  and  90  are further shaped to accommodate neighboring gripping members  60  so that each can operate properly without hindrance. For example, an outer vertical edge of fingers  80  and  90  are flattened. 
     FIGS. 9–11  shows the interoperation between the elements of the AFORS.  FIG. 9  depicts the retrieval of flash/overflow  200  by gripping member  60  from a bottom mold portion  110 . Bottom mold portion  110  is cup-shaped cavity, preferably substantially spherical, having a top rim  112  and a ledge  114  extending horizontally outward slightly beneath top rim  112 . Preferably both top rim  112  and ledge  114  are annular in shape. Ledge  114  sits on a flange  102  of bottom mold platen  100 , and bottom mold portion  110  is secured onto platen  100  with any means such as screws. During a molding process, flash/overflow  200 , typically substantially annular, is formed about top rim  112  of bottom mold portion  110  and rests on ledge  114 . After the molding process, bottom mold portion  110  is separated from other mold portions that form the mold cavity. Because of gravity interaction, the molded object such as golf balls or precursor thereof and flash/overflow  200  are usually left in or on bottom mold portion  110 . The molded object is preferably removed from bottom mold portion  110  first, using methods such as cup suction. The AFORS is then engaged to remove flash/overflow  200  from bottom mold portion  110 . 
   First, gripping assembly  50  is transported by rodless cylinder  20  from a starting position to an alignment position directly over bottom mold platen  100 . Guided cylinder  30  then extends downward to move gripping assembly  50  toward bottom mold platen  100 . Because alignment portion  75  of core post  70  has a circular and flat bottom surface that is concentric to and less in size than the top opening area of bottom mold portion  110 , alignment portion  75  is effectively inserted into bottom mold portion  110 . Referring to  FIG. 9 , outer surface  78  of alignment portion  75  is in contact with upper inner wall  116  of bottom mold portion  110 , and brink  76  of gripping portion  71  is in contact with top rim  112  of bottom mold portion  110 . This construction allows core post  70  to perfectly self-align or center with its corresponding bottom mold portion  110 . Guided cylinder  30  is extended further to fully compress part ejector  66  between gripper body  62  and core post  70  of gripping member  60  (pre-loading). Pneumatic power supplied to guided cylinder  30  is properly regulated to be enough to achieve full compression of part ejector  66 , but not too much to cause excessive wear between core post  70  and bottom mold portion  110 . 
   In this pre-loaded position, fingers  80  (shown) and  90  (not shown) are located so that tip  82  and  92  just clear top surface  106  of bottom mold platen  100  without actual contact. Fingers  80  and  90  are moved concentrically toward axis C until inner surfaces  88  and  98  are pressed firmly against flash/overflow  200 , which is in turn pressed firmly against lower outer surface  74  of gripping portion  71  of core post  70 . In this way, flash/overflow  200  is securely held between fingers  80  and  90  and core post  70 . Immobilized fingers  80  and  90  keep ejector  66  compressed between gripper body  62  and core post  70  through flash/overflow  200  and lower outer surface  74  of core post  70 . Movements of fingers  80  and  90  are controlled through jaws  68  on which they are mounted. Such movements are preferably synchronized so that fingers  80  and  90  operate in parallel, or optionally the jaws  68  are independently controlled. 
     FIG. 10  illustrates gripping member  60  holding flash/overflow  200 . After gripping members  60  retrieve flash/overflow  200 , guided cylinder  30  retracts its mobile end  38  to bring gripping assembly  50  upward and away from bottom mold platen  100 . Rodless cylinder  20  is engaged to move guided cylinder  30  and gripping assembly  50  from the alignment position back to a pre-determined position, preferably the starting position.  FIG. 11  shows the discharge of flash/overflow  200  from gripping member  60 . Fingers  80  and  90  of gripping member  60  are moved concentrically outward to loose their grip on flash/overflow  200 . Part ejector  66  decompresses to propel core post  70  downward, effectively expelling flash/overflow  200  off from core post  70 . The inverted frustoconical profile of lower outer surface  74  and recessed alignment portion  75  eliminate any friction that may retain flash/overflow  200  during expulsion. Flash/overflow  200  is preferably dropped into a chute and collected in a waste bin for disposal. Gripping members  60  are now ready for further flash/overflow retrieval. 
   To improve efficiency and reduce wear of the AFORS of the present invention, it is preferred to move multiple bottom mold platens  100  carrying flash/overflow  200  through a stationary construction that houses the AFORS. Mold platens  100  are preferably placed on a conveyor (with rolling pins or belt) to pass through the AFORS. Any other moving means known to the skilled in the art may be used as well. Two or more conveyor lines are arranged in parallel, each with its own designated AFORS and independent operation, to multiply processing capacity. Preferably, one conveyor carries top mold platens, and the other conveyor carries bottom mold platens. 
   An automated inspection system is optionally employed to check the presence of flash/overflow  200  on each bottom mold portion  110  prior to engaging the AFORS. In one embodiment, a cylinder is lowered over mold portion  110  toward a pre-determined position just above ledger  114 . When flash/overflow  200  is present, it prevents the cylinder from reaching the pre-determined position. The AFORS is in turn signaled for flash/overflow removal. When flash/overflow  200  is absent, the cylinder does reach the pre-determined position, and signals the AFORS not to engage for removal. In another embodiment, the inspection system may employ an imaging system that differentiates optical differences (color, reflection, etc.) between flash/overflow  200  and mold portion  110 , thereby detecting the presence of flash/overflow  200 . In a further embodiment, a laser diode-based or ultrasound-based distance measurement system can be used to verify the presence of flash/overflow  200 . When flash/overflow  200  is absent on a particular bottom mold portion  110 , the corresponding gripping member  60  is signaled not to engage for retrieval, thereby reducing wear. Alternatively, the AFORS is signaled to be idol only when flash/overflow  200  is missing from all of the mold portions  110  on the same mold platen  100 . 
   Material wear mostly occurs in core post  70  and fingers  80  and  90 , because of their direct and repeated contact with flash/overflow  200 . Durable materials are desired to construct these components, so as to reduce replacement cost and related downtime. Suitable materials for core post  70  and fingers  80  and  90  can be metals or plastics, having a material hardness and a flexural modulus greater than that of flash/overflow  200 , and a low coefficient of friction so that flash/overflow  200  does not stick during expulsion. The material hardness is preferably greater than about 55 Shore D, more preferably about 60 Shore D to about 95 Shore D. The coefficient of friction is preferably less than about 0.4, more preferably about 0.05 to about 0.3. The flexural modulus is preferably greater than about 70,000 psi, more preferably about 100,000 psi to about 4,500,000 psi. Fingers  80  and  90  preferably have a tensile strength of greater than about 5,000 psi, more preferably greater than about 10,000 psi. Exemplary plastic materials for core post  70  include, but are not limited to, thermoplastics and thermosets such as acetal homopolymers and copolymers, polytetrafluoroethylene, polyperfluoroalkoxyethylene, fluorinated ethylene propylene, ethylene tetrafluoroethylene, ethylene chloro-trifluoroethylene, polyvinylidiene fluoride, polyketones, polyetheretherketones, polyamides, polyamideimides, polyetherimides, high density polyethylene, polyphenylene sulfide, ultra-high-molecular-weight polyethylene, and all plastics available from Quadrant Engineering Plastic Products of Reading, Pa. In a preferred embodiment, core post  70  is made from high density polyethylene, and fingers  80  and  90  are made from acetal homopolymer (Delrin® by DuPont). 
   The pneumatic pressure supplied to the AFORS can be any pressure high enough to allow all the operations described above. Preferably, the pneumatic pressure is about 90 psi. Changes in the pressures that lead to all mechanical movements in the AFORS are regulated by single and/or double solenoid valves that are disposed along the hoses that connect the gas tanks or cylinders to the inlets/outlets. Other designs and features suitable for the AFORS are well known to one of ordinary skill in the art, and can be incorporated into the present invention whenever appropriate. 
   All patents and patent applications cited in the foregoing text are expressly incorporated herein by reference in their entirety. 
   The invention described and claimed herein is not to be limited in scope by the specific embodiments herein disclosed, since these embodiments are intended as illustrations of several aspects of the invention. Any equivalent embodiments are intended to be within the scope of this invention. Indeed, various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art from the foregoing description. Such modifications are also intended to fall within the scope of the appended claims.