Abstract:
A golf ball comprising a center and at least one cover layer, formed from the steps of providing a plurality of centers; providing a top mold plate defining a first plurality of cavities, a bottom mold plate defining a second plurality of cavities corresponding to the first cavities, and a center mold plate disposed between the top and bottom mold plates and comprising a plurality of corresponding protrusions; forming a plurality of shells from a layer material by: i) placing the layer material into the top and bottom mold plate cavities; and ii) molding the layer material around the protrusions of the center plate by applying heat and pressure to the top and bottom mold plates such that the layer material has a different temperature than the mold plates; opening at least one of the top or bottom mold plates from the center plate and placing the centers in the shells; and joining the top and bottom mold plates to join the shells around the centers.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a divisional of U.S. application Ser. No. 09/975,177, which is a continuation of U.S. Pat. No. 6,303,065, filed Aug. 17, 1999, both of which are incorporated herein, in their entirety, by express reference thereto. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention is directed to golf balls and/or golf ball cores. More particularly, the invention is directed to multi-layered cores or golf balls that are formed from a substantially automated process.  
         BACKGROUND OF THE INVENTION  
         [0003]    Generally, golf balls have been classified as solid balls or wound balls. Solid balls are generally comprised of a solid polymeric core and a cover. These balls are generally easy to manufacture, but are regarded as having limited playing characteristics. Wound balls are comprised of a solid or liquid-filled center surrounded by tensioned elastomeric material and a cover. Wound balls generally have good playing characteristics, but are more difficult to manufacture than solid balls.  
           [0004]    The prior art is comprised of various golf balls that have been designed to provide optimal playing characteristics. These characteristics are generally the initial velocity and spin of the golf ball, which can be optimized for various players. For instance, certain players prefer to play a ball that has a high spin rate for playability. Other players prefer to play a ball that has a low spin rate to maximize distance. However, these balls tend to be hard feeling and difficult to control around the greens.  
           [0005]    Manufacturers have molded layers around a solid center by placing a preformed center between two blocks of core material in a spherical compression mold, and closing the mold. This process, however, provides little control over the ultimate placement of the center within the golf ball core. Large variations in the location of the center can result.  
           [0006]    The prior art also provides for the manufacture of double cover golf balls. This is generally accomplished by injection molding a first and then a second cover layer around a core. This system, however, requires complex injection molds, usually with retractable pins within the mold to properly position the core. Moreover, this system generally works better with thermoplastic materials.  
           [0007]    Therefore, what is desired is a method and apparatus for molding multi-layer cores or multi-layer covers that ensures properly centered balls.  
         SUMMARY OF THE INVENTION  
         [0008]    The present invention is directed to a method of making a golf ball core, comprising the steps of providing a plurality of centers; providing a top mold plate defining a first plurality of cavities, a bottom mold plate defining a second plurality of cavities corresponding to the first cavities, and a center mold plate disposed between the top and bottom mold plates and comprising a plurality of corresponding protrusions; forming a plurality of shells from a layer material by placing the layer material into the top and bottom mold plate cavities; and molding the layer material around the protrusions of the center plate by applying at least one of heat and pressure to the top and bottom mold plates such that the layer material has a different temperature than the mold plates; opening at least one mold plate from the center plate and placing the centers in the shells; and joining the top and bottom mold plates to join the shells around the centers.  
           [0009]    Additionally, the step of forming a plurality of shells may further include the step of locating the top mold plate between the center and bottom mold plates so that the cavities in the top mold plate are adjacent to the center mold plate and the top, center and bottom mold plates are vertically aligned.  
           [0010]    In one embodiment, the step of locating the top mold plate further includes vertically moving the center mold plate from an elevated position to a rotate position. The step of locating the top mold plate may further include vertically moving the top mold plate from a lower position to the rotate position. Following the step of applying heat and pressure to the top and bottom mold plates, the center mold plate may be vertically moved from the rotate position to the elevated position, and vertically moving the top mold plate from the rotate position to the lower position.  
           [0011]    In another embodiment, the step of locating the top mold plate further includes horizontally moving the center mold plate from a first position substantially vertically unaligned with the top mold plate to a second position substantially vertically aligned with the top mold plate. Additionally, the step of forming a plurality of core hemispherical shells from elastomeric material further includes providing a lower elevator having a movable upper plate; and after applying heat and pressure to the top and bottom mold plates, separating the mold plates by moving the upper plate upward. The step of forming a plurality of shells may preferably include placing elastomeric material into the top and bottom mold plate cavities.  
           [0012]    The present invention is also directed to a golf ball comprising a center and at least one cover layer, formed from the steps of providing a plurality of centers; providing a top mold plate defining a first plurality of cavities, a bottom mold plate defining a second plurality of cavities corresponding to the first cavities, and a center mold plate disposed between the top and bottom mold plates and comprising a plurality of corresponding protrusions; forming a plurality of shells from a layer material by placing the layer material into the top and bottom mold plate cavities; and molding the layer material around the protrusions of the center plate by applying at least one of heat and pressure to the top and bottom mold plates such that the layer material has a different temperature than the mold plates; opening at least one mold plate from the center plate and placing the centers in the shells; and joining the top and bottom mold plates to join the shells around the centers.  
           [0013]    Preferably, the cover layer is an outer core layer, an inner cover layer, or an outer cover layer and includes a fully-neutralized ionic copolymer or terpolymer. Typically, the fully-neutralized ionic copolymers or terpolymers include methacrylic, crotonic, maleic, fumaric, or itaconic acid.  
           [0014]    The cover layer should have a thickness of between about 0.03 inches and about 0.12 inches and preferably comprises a polyurethane or a polyurea. The center and shells can also be disposed concentrically within a layer of tensioned elastomeric material. Additionally, the center and shells define a core having an outer diameter of between about 1.3 inches and about 1.7 inches, preferably between about 1.5 inches and about 1.6 inches. In another embodiment, the center, shells, and cover layer have an outer diameter of between about 1.3 inches and about 1.7 inches.  
           [0015]    Ideally, the cover layer is an inner cover layer and includes partially- or fully-neutralized ionomers, polyolefins, polyurethanes, polyureas, polyamides, acrylic resins, polyphenylene oxide resins, thermoplastic polyesters, thermoplastic rubbers, or ethylene-, propylene-, butene-, or hexane-based homo- and co-polymers or their functional monomers. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    [0016]FIG. 1 is a cross-sectional view of a liquid-filled ball formed using the method and apparatus of the present invention;  
         [0017]    [0017]FIG. 2 is a cross-sectional view of a solid ball formed using the method and apparatus of the present invention;  
         [0018]    [0018]FIG. 3 is a perspective view of a molding apparatus according to the present invention;  
         [0019]    [0019]FIG. 4 is an enlarged, side view of a lower elevator assembly prior to engaging a bottom mold plate;  
         [0020]    [0020]FIG. 5 is a perspective view of a frame assembly of the apparatus of FIG. 3;  
         [0021]    [0021]FIG. 6 is an enlarged, perspective view of a guide assembly on the frame assembly of FIG. 5;  
         [0022]    [0022]FIG. 7 is an enlarged, perspective view of a slide assembly of the apparatus;  
         [0023]    [0023]FIG. 8 is an enlarged, perspective view of the lower elevator assembly of the apparatus of FIG. 3;  
         [0024]    [0024]FIG. 9 is an enlarged, perspective view of an upper elevator assembly of the apparatus of FIG. 3;  
         [0025]    [0025]FIG. 10 is a partial enlarged, perspective view of a portion of the frame assembly shown in FIG. 3;  
         [0026]    [0026]FIG. 10A is an enlarged, partial, cross-sectional view of a rotating assembly taken along arrow  10 A- 10 A of FIG. 10;  
         [0027]    [0027]FIG. 11 is an enlarged, partial, top view of the rotating assembly of FIG. 10A with a top mold plate retained therein;  
         [0028]    [0028]FIG. 12 is an exploded, enlarged, perspective view of a lock assembly of the apparatus of FIG. 3;  
         [0029]    [0029]FIG. 13 is an enlarged, perspective view of a mold press of the apparatus of FIG. 3, wherein portions are broken away for clarity;  
         [0030]    [0030]FIG. 14 is an enlarged, top view of the bottom mold plate shown in FIG. 4;  
         [0031]    [0031]FIG. 15 is an enlarged, top view of the top mold plate shown in FIG. 4;  
         [0032]    [0032]FIG. 16 is an enlarged, top view of a center mold plate shown in FIG. 4; and  
         [0033]    [0033]FIGS. 17 and 18 are schematic perspective views illustrating step-by-step the method of forming a two-layer core according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0034]    Referring to FIG. 1, ball  2  includes a cover  4  surrounding a core  5 . The core  5  has a center or inner core  6  that is disposed concentrically within the cover and is a fluid center  7  in a cavity within an inner layer  8 . The core  5  also has an outer core  9 , which surrounds the center  6 .  
         [0035]    Referring to FIG. 2, ball  2 ′ includes a cover  4  surrounding a core  5 . The core  5  has a center or inner core  6 ′ that is disposed concentrically within the cover, and which comprises a solid sphere, as set forth below. The core  5  also has an outer core  9 , which surrounds the center  6 ′.  
         [0036]    The cover  4  provides the interface between the ball  2  or  2 ′ and a club and other objects such as trees, cart paths, and grass. Properties that are desirable for the cover are good moldability, high abrasion resistance, high tear strength, high resilience, and good mold release, among others.  
         [0037]    The cover  4  can be comprised of polymeric materials such as ionic copolymers of ethylene and an unsaturated monocarboxylic acid, which are available under the trademark SURLYN® of E. I. DuPont de Nemours &amp; Company of Wilmington, Del. or IOTEK® or ESCOR® from Exxon. These are copolymers or terpolymers of ethylene and methacrylic acid or acrylic acid partially neutralized with zinc, sodium, lithium, magnesium, potassium, calcium, manganese, nickel or the like.  
         [0038]    In accordance with the preferred balls, the cover  4  has a thickness to generally provide sufficient strength, good performance characteristics and durability. Preferably, the cover  4  is of a thickness from about 0.03 inches to about 0.12 inches. More preferably, the cover  4  is about 0.04 to 0.09 inches in thickness and, most preferably, is about 0.05 to 0.085 inches in thickness.  
         [0039]    In one preferred embodiment, the cover  4  can be formed from mixtures or blends of zinc, lithium and/or sodium ionic copolymers or terpolymers.  
         [0040]    The SURLYN® resins for use in the cover  4  are ionic copolymers or terpolymers in which sodium, lithium or zinc salts are the reaction product of an olefin having from 2 to 8 carbon atoms and an unsaturated monocarboxylic acid having 3 to 8 carbon atoms. The carboxylic acid groups of the copolymer may be totally or partially neutralized and might include methacrylic, crotonic, maleic, fumaric or itaconic acid.  
         [0041]    This invention can likewise be used in conjunction with homopolymeric and copolymer materials such as:  
         [0042]    (1) Vinyl resins such as those formed by the polymerization of vinyl chloride, or by the copolymerization of vinyl chloride with vinyl acetate, acrylic esters or vinylidene chloride.  
         [0043]    (2) Polyolefins such as polyethylene, polypropylene, polybutylene and copolymers such as ethylene methylacrylate, ethylene ethylacrylate, ethylene vinyl acetate, ethylene methacrylic or ethylene acrylic acid or propylene acrylic acid and copolymers and homopolymers produced using single-site catalyst.  
         [0044]    (3) Polyurethanes such as those prepared from polyols and diisocyanates or polyisocyanates and those disclosed in U.S. Pat. No. 5,334,673.  
         [0045]    (4) Polyureas such as those disclosed in U.S. Pat. No. 5,484,870.  
         [0046]    (5) Polyamides such as poly(hexamethylene adipamide) and others prepared from diamines and dibasic acids, as well as those from amino acids such as poly(caprolactam), and blends of polyamides with SURLYN®, polyethylene, ethylene copolymers, ethyl-propylene-non-conjugated diene terpolymer, etc.  
         [0047]    (6) Acrylic resins and blends of these resins with poly vinyl chloride, elastomers, etc.  
         [0048]    (7) Thermoplastics such as the urethanes, olefinic thermoplastic rubbers such as blends of polyolefins with ethylene-propylene-non-conjugated diene terpolymer, block copolymers of styrene and butadiene, isoprene or ethylene-butylene rubber, or copoly (ether-amide), such as PEBAX® sold by ELF Atochem.  
         [0049]    (8) Polyphenylene oxide resins, or blends of polyphenylene oxide with high impact polystyrene as sold under the trademark NORYL® by General Electric Company, Pittsfield, Mass.  
         [0050]    (9) Thermoplastic polyesters, such as polyethylene terephthalate, polybutylene terephtha late, polyethylene terephthalate/glycol modified and elastomers sold under the trademarks HYTREL® by E. I. DuPont de Nemours &amp; Company of Wilmington, Del. and LOMOD® by General Electric Company of Pittsfield, Mass.  
         [0051]    (10) Blends and alloys, including polycarbonate with acrylonitrile butadiene styrene, polybutylene terephthalate, polyethylene terephthalate, styrene maleic anhydride, polyethylene, elastomers, etc. and polyvinyl chloride with acrylonitrile butadiene styrene or ethylene vinyl acetate or other elastomers. Blends of thermoplastic rubbers with polyethylene, propylene, polyacetal, nylon, polyesters, cellulose esters, etc.  
         [0052]    Preferably, the cover  4  is comprised of polymers such as ethylene, propylene, butene-1 or hexane-1 based homopolymers and copolymers including functional monomers such as acrylic and methacrylic acid and fully or partially neutralized ionomer resins and their blends, methyl acrylate, methyl methacrylate homopolymers and copolymers, imidized, amino group containing polymers, polycarbonate, reinforced polyamides, polyphenylene oxide, high impact polystyrene, polyether ketone, polysulfone, poly(phenylene sulfide), acrylonitrile-butadiene, acrylic-styrene-acrylonitrile, poly(ethylene terephthalate), poly(butylene terephthalate), poly(ethylene vinyl alcohol), poly(tetrafluoroethylene) and their copolymers including functional comonomers and blends thereof. Still further, the cover  4  is preferably comprised of a polyether or polyester thermoplastic urethane, a thermoset polyurethane, a low modulus ionomer such as acid-containing ethylene copolymer ionomers, including E/X/Y terpolymers where E is ethylene, X is an acrylate or methacrylate-based softening comonomer present in 0-50 weight percent and Y is acrylic or methacrylic acid present in 5-35 weight percent. More preferably, in a low spin rate embodiment designed for maximum distance, the acrylic or methacrylic acid is present in 15-35 weight percent, making the ionomer a high modulus ionomer. In a high spin embodiment, the acid is present in 10-15 weight percent or a blend of a low modulus ionomer with a standard ionomer is used.  
         [0053]    The outer core  9  is preferably made of thermoset rubber base materials, including those conventionally employed in golf ball cores. The conventional materials for such cores include compositions having a base rubber, a crosslinking agent, a filler and a co-crosslinking agent. The base rubber is typically a synthetic rubber like 1,4-polybutadiene having a cis-structure of at least 40%. Natural rubber, polyisoprene rubber and/or styrene-butadiene rubber may optionally be added to the 1,4-polybutadiene. The initiator included in the core composition can be any polymerization initiator which decomposes during the cure cycle. The crosslinking agent includes a metal salt of an unsaturated fatty acid such as sodium, zinc, lithium or magnesium salt or an unsaturated fatty acid having 3 to 8 carbon atoms such as acrylic or methacrylic acid. The filler typically includes materials such as zinc oxide, barium sulfate, silica, calcium carbonate, zinc carbonate, regrind and the like.  
         [0054]    Alternatively, the outer core  9  may be comprised of thermoplastic elastomers such as a thermoplastic polyesterester, thermoplastic polyetherester, dynamically vulcanized thermoplastic elastomers, functionalized styrene-butadiene elastomers, thermoplastic urethanes or metallocene polymers or blends thereof.  
         [0055]    The present invention is not limited to a particular outer core  9  material, and the materials are well known to those of ordinary skill in the art. The present invention is generally directed to the use of a standard thermoset material, but those of ordinary skill will easily know how to convert the process for using thermoplastic materials.  
         [0056]    The outer core  9  preferably has an outside diameter in the range of 80 to 98% of the finished ball diameter and an inner diameter in the range of 30 to 90% of the finished ball diameter. Preferably, the outer core  9  has an inner diameter of approximately 0.8 to 1.5 inches and, more preferably, the inner diameter is approximately 1.0 to 1.5 inches. Yet further still, the outer core  16  has an outside diameter in the range of 1.3 to 1.7 inches and, more preferably, approximately 1.5 to 1.6 inches.  
         [0057]    A golf ball incorporating these measurements can be designed with the various attributes discussed below, such as specific gravity, resiliency and hardness, to provide the desired playing characteristics, such as spin rate and initial velocity.  
         [0058]    Referring to FIG. 3, the method for making golf balls of the present invention uses a molding apparatus  10 . The molding apparatus  10  includes a frame assembly  12 , a guide assembly  14 , a slide assembly  16 , a lower elevator assembly  18 , an upper elevator assembly  20 , a rotating assembly  22 , a light source  24 , sensors  26 , a plurality of lock assemblies  28 , controls (not shown), and a mold press  30 . Preferably a combination of pneumatic, electrical, and computerized systems are used to control the operation of the apparatus, however any conventional manufacturing controls known to those skilled in the art can be used to control the apparatus operation. Referring to FIG. 4, the molding apparatus  10  further includes a bottom mold plate  32 , a top mold plate  34 , and a center mold plate  36 .  
         [0059]    Referring to FIG. 5, the frame assembly  12  includes two frame sections  38  and  40  joined to form a substantially L-shaped frame. Reference is made to a three-dimensional Cartesian Coordinate system including perpendicular x, y, and z axes or directions. The frame sections  38  and  40  include elongated members that form rectangular three-dimensional boxes. The first frame section or slide frame  38  is elongated more in the y-direction than in the x- and z-directions, so the slide frame  38  extends substantially horizontally and longitudinally. The second frame section or elevator frame  40  is elongated more in the z-direction than in the x- and y-directions, so that the elevator frame extends substantially vertically.  
         [0060]    Referring to FIG. 5, the slide frame  38  has a first end  38   a,  a spaced second end  38   b,  and further includes a pair of lower longitudinal members  42 , a pair of upper longitudinal members  44 , four pairs of vertical members  46 , four upper transverse members  48 , four lower transverse members  50 , and a pair of inclined members  52 .  
         [0061]    The pair of upper longitudinal members  44  are longer than the pair of lower longitudinal members  42  such that the upper pair  44  extend beyond the lower pair  42  at the second end  38   b  of the slide frame  38 .  
         [0062]    The pairs of vertical members  46  join the lower and upper longitudinally extending members  42  and  44 . Each pair of vertical members  46  are spaced longitudinally from the adjacent pair.  
         [0063]    The upper transverse members  48  extend between the upper longitudinal members  44 . The lower transverse members  50  extend between the lower longitudinal members  42 . Each inclined member  52  extends from the center of the associated vertical member  46  at the second end  38   b  to the second end  38   b  of the upper longitudinal member  44 .  
         [0064]    The upper longitudinal members  44  and the three upper transverse members  48  closest to the second end  38   b  include spaced frame pads  54  of various sizes attached to the upper surfaces thereof. The various sized pads define either one or two holes, which extend through the entire pad to enable mounting of the guide assembly  14  (as shown in FIG. 3) on the upper surface of the pads using conventional fasteners.  
         [0065]    The slide frame  38  further includes two reflector assemblies  56  attached thereto at the first end  38   a . Each reflector assembly  56  includes an upper mount plate  58 , a lower mount plate  60 , a lower mount member  62 , a vertical member  64 , an upper mount member  66 , a tubular member  68 , and a mirror  70 .  
         [0066]    The upper mount plate  58  is coupled to the upper corner of the slide frame  38  above the vertical member  46  at the first end  38   a . The lower mount plate  60  is coupled to the center of the vertical member  46  at the first end  38   a . The lower mount member  62  is coupled to and horizontally extends from the lower mount plate  60 . The vertical member  64  extends vertically from the upper surface of the upper mount plate  58 . The upper mount member  66  is coupled to and horizontally extends from the vertical member  64 . The lower and upper mount members  62  and  66  are parallel to one another and extend away from the first end  38   a  of the slide frame  38 . The tubular member  68  extends between the lower and upper mount members  62  and  66 . The lower and upper mount plates  58  and  60 , mount members  62  and  66 , the vertical member  64  and the tubular member  68  are joined together using conventional fasteners. The mirror  70  is rotatably mounted to the tubular member  68 .  
         [0067]    Referring again to FIG. 5, the elevator frame  40  is aligned with the slide frame  38 , and includes a lower rectangular frame  72 , a spaced upper rectangular frame  74 , a plurality of vertical members  76 , a rotating assembly mount frame  80 , and a light source/receiver unit  82  (as shown in FIG. 3).  
         [0068]    Referring to FIG. 5, the lower rectangular frame  72  is coupled to the lower longitudinal members  42  of the slide frame  38 . The elevator frame  40  supports the slide frame  38  that extends therethrough. The vertical members  76  join the lower and upper frames  72  and  74  of the elevator frame  40 . One vertical member  76  connects each corner of the lower frame  72  to each corner of the upper frame  74 .  
         [0069]    At least one of the vertical members  76  includes a bracket  84  that is attached thereto. The bracket  84  supports a hydraulic cushion  86  (as shown in FIG. 10) that is attached thereto.  
         [0070]    The upper rectangular frame  74  further includes two pairs of upper elevator support members  88  and  90 . The support members  88  extend longitudinally and are spaced apart. The first pair of upper elevator support members  88  is connected to the upper rectangular frame  74  by brackets  92 . The support members  90  extend transversely between the first pair of upper elevator support members  88 .  
         [0071]    The rotating assembly mount frame  80  includes two pairs of longitudinally extending mount members  94 . The members  94  extend between the vertical support members  76 , respectively. The mount members  94  are vertically positioned between the slide frame  38  and the upper frame  74 .  
         [0072]    Referring to FIG. 3, a pair of sensor array supports  96  extend longitudinally between the vertical members  76 . The supports  96  are located on the upper end of the elevator frame  40  between the rotating assembly mount frame  80  and the upper frame  74 . Each sensor array support  96  is secured to the elevator frame  40  by brackets  98 , which are mounted to the vertical members  76 .  
         [0073]    Referring to FIG. 3, one light source/receiver unit  100  is attached to each of the vertical support members  76  closest to the slide frame first end  38   a . Each unit  100  produces a light beam that travels the longitudinal length of the slide frame  38  toward the mirror  70 . Each unit  100  is in electronic communication with the controls. The mirror  70  reflects the beam of light back toward the unit  100 .  
         [0074]    When the unit  100  receives the light, a circuit is completed. If the light path from the mirror  70  to the unit  100  is obstructed, the circuit will not be completed. An incomplete circuit causes a signal to be sent to the controls from the unit  100 . The signal prevents movement of various parts of the apparatus along the slide frame  38 .  
         [0075]    Referring to FIG. 6, the guide assembly  14  includes three pairs of guide blocks  102 - 106  mounted to the upper surface of the upper longitudinal members  44  of the slide frame  38  on the pads. The first pair of guide blocks  102  closest to the second end  38   b  of the slide frame  38  defines a working station W. The second pair of guide blocks  104  defines an intermediate loading station IL. The third pair of guide blocks  106  defines an end loading station EL.  
         [0076]    Each guide block  102 - 106  is a rectangular track with two sets of cam-follower bearings  108  and  110 . In the first set, the cam-follower bearings  108  are rotatably coupled to the upper surface of each guide block. Cam-follower bearings  108  rotate about an axis z′ that is parallel to the z-axis. In the second set, the cam-follower bearings  110  are rotatably coupled to the inner, side surface of each guide block. Cam-follower bearings  110  rotate about an axis x′ that is parallel to the x-axis. During operation, the second set of cam-follower bearings  110  support the mold plates thereon, and the first set of cam-follower bearings  108  prevent the mold plates from moving in the transverse, or x-direction.  
         [0077]    The first pair of guide blocks  102  further includes two sets of working station lock assemblies  28 W and  28 W′ coupled thereto that secure various mold plates in the working station W. The lock assemblies  28 W and  28 W′ are coupled to the first pair of guide blocks  102  so that they extend transversely therefrom. The first set of working station lock assemblies  28 W is spaced vertically from the second set of working station lock assemblies  28 W′ to allow two mold plates to be secured simultaneously at the working station W. Each set of assemblies  28 W and  28 W′ has a forward pair of assemblies and a rearward pair of assemblies, where one lock assembly in the pair is coupled to the opposing guide block.  
         [0078]    The second and third pair of guide blocks  104  and  106  each have a pair of intermediate and end loading lock assemblies  28 IL and  28 EL, which are vertically coupled to extensions on the guide blocks. The lock assemblies  28 IL and  28 EL secure various plates thereabove in the intermediate or end loading station, respectively.  
         [0079]    Referring to FIGS.  5 - 7 , the slide assembly  16  transports the mold plates longitudinally along the slide frame  38  between the various stations W, IL and EL. The slide assembly  16  includes a base assembly  112 , a sliding member  114 , and a plurality of slide lock assemblies  28 S and  28 S′.  
         [0080]    Referring to FIG. 7, the base assembly  112  includes two spaced support feet  116 , a floor member  118 , and a rectangular side wall member  120 . When the slide assembly  16  is assembled to the slide frame  38 , the support feet  116  are connected to the central, upper transverse members  48  (as shown in FIG. 5). The floor member  118  extends horizontally between the support feet  116  and is connected thereto. The rectangular side wall member  120  is coupled to the floor member  118  and extends vertically therefrom. The side wall member  120  forms a chamber  122  that receives a motorized linear slide  124 . The linear slide  124  causes the sliding member  114  to move longitudinally. One recommended linear slide is commercially available from Thomson Industries Inc. located in Fort Washington, N.Y. and called AccuSlide. However, any conventional motorized slide known to those skilled in the art can be used. Other types of components can also be used to move plates longitudinally instead of the linear slide, such as a belt drive.  
         [0081]    The linear slide  124  has a ball screw  126  operatively connected to a servo motor  128 . The servo motor  128  is connected to a first end of the side wall member  120  for driving the ball screw  126 . A ball bushing bearing  130  is operatively connected to and travels along the ball screw  126  and is coupled to the sliding member  114 .  
         [0082]    The sliding member  114  is H-shaped and includes two spaced mounting plates  132  joined by a plate  134 . The slide lock assemblies  28 S and  28 S′ are coupled to the ends of the mounting plates  132  and releasably couple the mold plates to the sliding member  114 . The sliding member  114  is shown in an extended position, where the sliding member  114  is unaligned with the base assembly  112 . Sensors (not shown) are mounted on the base assembly  112  to detect the position of the sliding member  114 .  
         [0083]    Referring to FIGS. 4 and 8, the lower elevator assembly  18  includes a lower plate  136 , an actuation assembly  138 , and a movable, upper plate  140 . The lower plate  136  is connected to the slide frame  38  within the elevator frame  40 . Each of the lower and upper plates  136  and  140  define first holes (not shown) at the corners for receiving guide rods  142 . Each of the plates also define a second hole (not shown) at the center of each plate for receiving a central shaft  144 .  
         [0084]    The upper surface of the lower plate  136  further includes four ball bushing blocks  146 . The blocks  146  are at the corners for receiving the rods  142 . Each ball bushing block  146  has a bushing  150  secured thereto for receiving each guide rod  142  and allowing smooth vertical movement of the guide rods  142  through the block  146  and lower plate  136 . When each guide rod  142  is disposed through the first holes and bushing blocks, the first end  142 a of each guide rod  142  is below the lower plate  136  and the second end of each guide rod  142  receives a top cap  152  for fixedly connecting the guide rod  142  to the upper plate  140 .  
         [0085]    One of the ball bushing blocks  146  includes a home sensor  154  mounted thereto to indicate when the upper plate  140  is in a lower position. An upper limit sensor (not shown) is mounted in the elevator frame  40  (as shown in FIG. 4) at the rotate or central position to indicate the upper limit of the top plate  140  of the lower elevator assembly  18 . The top plate  140  moves between a lowest position beneath the level of the guide blocks  102  (as shown in FIG. 6) and the rotate position.  
         [0086]    The actuation assembly  138  for moving the upper plate  140  vertically includes a servo motor  154  and a jack screw  156 . The servo motor  154  is connected to the lower plate  136  and operatively connected to the jack screw  156 . The central shaft  144  has a first end  144   a  beneath the lower plate  136  and a second end above the upper plate  140 . A shaft coupling  158  operatively connects the jack screw  156  to the central shaft  146 . A screw cap  160  is connected to the second end of the central shaft  144  to fixedly couple the central shaft  144  to the upper plate  140 .  
         [0087]    The upper plate  140  defines a cutout  162  and includes a plurality of lift elements  164 . As shown in FIG. 3, once the lower elevator  18  is installed, cutout  162  is aligned with the slide assembly  16  to allow the upper plate  140  to move without the slide assembly  16  interfering with the movement of the upper plate.  
         [0088]    Referring again to FIG. 8, the lift elements  164  are disposed at each corner on the upper surface of the upper plate  140 . The lift elements  164  engage the mold plates, upon vertical movement of the upper plate  140  to separate the plates from one another.  
         [0089]    Referring to FIG. 8, each lift element  164  includes a block  166  having an upper surface  168 , and a lift pin  170  extending vertically therefrom. Each lift pin  170  includes a cylindrical base portion  172  and a cylindrical upper portion  174 . The diameter of the base portion  172  is larger than the diameter of the upper portion  174 . The base portion  172  and the upper portion  174  are separated by a shoulder  176 . Each pin further includes a free end  178 .  
         [0090]    Referring to FIG. 9, the upper elevator assembly  20  includes a movable lower plate  180 , an actuation assembly  182 , and an upper plate  184 . The upper plate  184  is connected to the support members  88  and  90  (as shown in FIG. 5) within the elevator frame  40 .  
         [0091]    Each of the lower and upper plates  180  and  184  define first holes (not shown) at the corners for receiving guide rods  186 . Each of the plates also define a second hole (not shown) at the center of each plate for receiving a central shaft  188 . The upper surface of the upper plate  184  further includes four ball bushing blocks  190  at the corners for receiving the rods  186 . Each ball bushing block  190  has a bushing  192  secured therein for receiving each guide rod  186  and allowing smooth vertical movement of the guide rods  186  through the block  190  and lower plate  180 .  
         [0092]    When the guide rod  186  is disposed through the first holes and the bushing blocks, the first end  186   a  of each guide rod  186  is above the upper plate  184 . The second end of each guide rod  186  receives a cap (not shown) for fixedly connecting the guide rod  186  to the lower plate  180 . One of the ball bushing blocks  190  includes a home sensor (not shown) mounted thereto to indicate when the lower plate is in an elevated or home position. A lower limit sensor (not shown) is mounted in the elevator frame  40  (as shown in FIG. 5) at the rotating position to indicate the lower limit of the lower plate of the upper elevator assembly.  
         [0093]    The upper surface of the lower plate  180  includes braces  194  with an X-shape for adding rigidity to the lower plate  180 . The lower plate  180  further includes two spaced, parallel, end walls  196  connected thereto, which extend vertically below the lower surface of the lower plate  180 . Each end wall  196  has a pair of upper elevator lock assemblies  28 UE attached thereto to releasably secure the center mold plate  34  (as shown in FIG. 4) to the upper elevator  20 .  
         [0094]    The upper surface of the upper plate  184  includes braces  198  with an X-shape for adding rigidity to the upper plate. The upper surface also has the actuation assembly  182  disposed thereon. The actuation assembly  182  includes a servo motor  200  and a jack screw  202  for moving the lower plate  180  vertically. The servo motor  200  is connected to the upper plate  184  and operatively connected to the jack screw  202 . The central shaft  188  has a first end  188   a  above the upper plate  184  and a second end (not shown). A shaft coupling  204  connects the jack screw  202  to the central shaft  188 . A bracket  206  is connected to the second end of the central shaft  188  to connect the central shaft  188  to the lower plate  180 .  
         [0095]    Referring now to FIGS. 10 and 10A, the rotating assembly  22  is mounted to the rotating mount frame  80 . The rotating assembly  22  includes an actuator assembly  208 , a pair of rotating subassemblies  210 , and a rotating frame  212 . The rotating assembly  22  is located within the elevator frame  40  so that the rotating frame  212  can rotate within the elevator frame 180° between an upright and an inverted position. To that end, the elevated position of the center mold plate, as discussed below, is spaced from the rotating position more than half the width of the rotating frame to allow rotation of the frame.  
         [0096]    The actuator assembly  208  is connected to a mount plate  214  that is coupled to the outside of the first pair of longitudinally extending mount members  94 . The actuator assembly  208  has a cylindrical shaft  216  that extends through the mount plate  214 . The actuator assembly  208  is a conventional air/oil tandem rotary actuator available from PHD, Inc. However, other components that impart rotary motion can be used. The shaft  216  is coupled to a first pivot shaft  218  by a bore coupling  220 . When the shaft  216  rotates, the first pivot shaft  218  also rotates. The rotation is about a rotate axis RA.  
         [0097]    The pair of rotating subassemblies  210  are mounted to the inside of the longitudinally extending mount members  94  on either side of the elevator frame. Each subassembly  210  includes a mount frame  222 , a horizontal adjustment plate  224 , a vertical adjustment plate  226 , a bearing  228 , and a second pivot shaft  230 .  
         [0098]    The mount frame  222  is coupled to the inside of one of the mount members  94 . As best shown in FIG. 5, the mount frame defines a central bore  232  for receiving the associated shaft  218  or  230 . The mount frame  222  also includes an outwardly extending shelf  234  for supporting the other components of the rotate assembly.  
         [0099]    Referring to FIG. 10A, the horizontal adjustment plate  224  defines a central hole  236  and is mounted adjacent to the mount frame  222 . The horizontal adjustment plate  224  is rectangular and also defines four horizontal slots (not shown) to accommodate screws and allow for horizontal adjustment of the pivot assemblies. The central hole  236  has a sufficiently large diameter to permit the second pivot shaft  230  with a smaller diameter to enter therein.  
         [0100]    The vertical adjustment plate  226  defines a central hole  238  and is mounted adjacent to the horizontal adjustment plate  224 . The vertical adjustment plate  226  is rectangular and defines four vertical slots (not shown) to accommodate screws and allow for vertical adjustment of the pivot assemblies. The central hole  238  has a sufficiently large diameter to permit the second pivot shaft  230  to enter therein and to receive the bearing  228 .  
         [0101]    The bearing  228  has a central hole  240  for receiving and supporting the first and second pivot shafts, respectively, and allowing rotation of the shafts. The combination of the horizontal and vertical adjustment plates  224  and  226  permits the adjustment of the bearing  228  to concentrically align with the first and second pivot shafts  218  and  230  during installation of the rotating frame  212 . The pivot shaft  218  and  230  are coupled to opposite sides of the rotating frame  212  (as best shown in FIG. 11).  
         [0102]    Referring to FIG. 8, the rotating frame  212  includes a pair of longitudinally extending side members  242   a  and  242   b  and a pair of transversely extending end members  244  fastened together to form a substantially square frame. The side members  242   a  and  242   b  include two sets of frame locking assemblies  28 F and  28 F′ secured thereto. The first set of locking assemblies  28 F is vertically spaced from the second set of locking assemblies  28 F′ so that the rotating frame  212  can support two mold plates. The first set of locking assemblies  28 F has two spaced assemblies at either end of the side members  242   a , and two spaced assemblies at either end of the side members  242   b . The second set of locking assemblies  28 F has two spaced assemblies at either end of the side members  242   a , and two spaced assemblies at either end of the side members  242   b.    
         [0103]    As shown in FIGS. 10 and 11, one end of one of the side members  242   a  includes a cushion block  246  and a sensor block  248 . The cushion and sensor blocks  246  and  248  are attached to opposite sides of the side member  242   a . The cushion block  246  is positioned so that when the rotating frame is horizontal, the cushion block  246  contacts the hydraulic cushion  86  to prevent excess rotation of the rotating frame  212 . The sensor block  248  senses when the cushion block  246  contacts the hydraulic cushion  86  to send a signal to the controls to stop rotation of the rotating frame  212 .  
         [0104]    Referring to FIG. 10, the end members  244  are horseshoe-shaped, and each has corner guide blocks  250  secured thereto. The corner guide blocks  250  align the rotating frame  212  with the lower elevator assembly  18  (as shown in FIG. 3) during operation.  
         [0105]    Referring to FIG. 3, light source  24  and sensors  26  are mounted on each sensor array support  96 . The light source  24  produces a light beam. The sensors  26  receive the light beam. If the sensors  26  do not receive the light beam, a circuit is not completed and a signal is sent to the controls. The purpose of the light source and sensors is to determine if any material is on the center mold plate  34  (as shown in FIG. 4), and discussed below.  
         [0106]    Referring to FIGS. 6, 7,  9 ,  11 , the working station lock assemblies  28 W and  28 W′, the loading station lock assemblies,  28 IL and  28 EL, the slide lock assemblies  28 S and  28 S′, the upper elevator lock assemblies  28 UE, and the frame lock assemblies  28 F and  28 F′ will now be discussed. Referring to FIG. 12, each lock assembly mentioned above includes an air cylinder assembly  252 , a cylinder nose  254 , a connector  256 , a floating coupling  258 , a lock body  260 , a pullout dowel  262 , and a bronze bushing  264 .  
         [0107]    The air cylinder assembly  252  includes a bracket housing  266 , an air cylinder  268 , and an air cylinder valve (not shown) for activating the air cylinder  268 . The air bracket housing  266  slidably receives the air cylinder  268 , and the air cylinder  268  extends therefrom.  
         [0108]    The cylinder nose  254  is connected to the free end of the air cylinder  268 . The cylinder nose  254  has a large diameter portion  254   a  and a small diameter portion  254   b . The large diameter portion  254   a  of the cylinder nose is disposed within the notch  270  defined in the floating coupling  258  to secure the nose  254  to the coupling  258 . The lock body  260  is coupled to the air cylinder assembly  252  by fasteners  272  and defines a central slot  274 . The bronze bushing  264  is secured to the opposite side of the lock body from the slot  274 . The pullout dowel  262  is slidably connected to the lock body  260  by the bushing  264 . The floating coupling  258  is, in turn, operatively connected to the pullout dowel  262  by the connector  256 . The slot  274  of the lock body  260  houses the connector  256 , the cylinder nose  254 , and floating coupling  258 .  
         [0109]    During operation of the lock assemblies  28 , the air cylinder  268  extends or retracts by actuation of the air cylinder valve. Consequently, movement of the cylinder  268  also causes the pullout dowel  262  to extend or retract so that the pullout dowel  262  engages and releases the various mold plates.  
         [0110]    Referring to FIG. 13, the mold press  30  is a hydraulic press commercially available from Brodeur Machine Company of New Bedford, Mass. under the name “slab-sided ram” hydraulic press. However, any mold press that is capable of producing the needed heat and pressure can be used. The mold press  30  has a base  276 , a press ram  278 , and a mold support assembly  280 .  
         [0111]    The base  276  includes two side slabs (one slab  282  being shown) that extend vertically to a top block  284 . The press ram  278  is located on the base  276  and moves a platen  279  to produce the pressure during molding. The press ram also supports various other moving platens, a steam platen, heating/cooling platens and insulation, as known by these of ordinary skill in the art.  
         [0112]    The mold support assembly  280  includes two support brackets  286  connected to the mold frame (not shown), pairs of support rods  288  and  290 , and a movable frame  292 . Each bracket  286  has the pair of first support rods  288  and a pair of second support rods  290  attached thereto. The first support rods  288  support an upper press plate  294 . The second support rods  290  support the frame  292  including a pair of spaced guide blocks  296 . The guide blocks  296  have cam-follower bearings  298  and  300  that are similar to those used with the guide blocks of the guide assembly  14  (as shown on FIG. 6).  
         [0113]    When the press ram  278  moves vertically, the platen  282  and frame  292  move vertically. The second support rods  290  guide the movement of the frame  292 . The upper press plate  294  horizontally spans the mold press  30  above the frame  292 . A lower press plate  302  horizontally spans the mold press and is supported by the frame  292 .  
         [0114]    Referring to FIG. 4, the bottom mold plate  32 , the top mold plate  34 , and the center mold plate  36  will now be discussed in detail. The bottom and top mold plates  32  and  34  include a plurality of hemispherical mating cavities  304  that form a sphere when the center mold plate  36  is not disposed between them. The cavities  304  are formed directly in the mold plates or comprised of replaceable mold cavities as set forth in U.S. Pat. No. 4,508,309 issued to Brown. The cavities  304  are formed with a radius substantially equal to the finished core radius. Preferably, this is in the range of about 1.50 inches to 1.65 inches as set forth above. Surrounding each of the cavities  304  is a circumferential groove  306  (as shown in FIGS. 14 and 15) for surplus outer core material.  
         [0115]    The center mold plate  36  includes a plurality of protrusions  307  on opposite sides thereof that correspond with the cavities  304  of the top and bottom mold plates. The protrusions  307  are hemispheres, which are substantially the same size as half of the ball inner core  13  (as shown in FIGS.  1 - 2 ), as set forth above.  
         [0116]    Referring to FIGS. 4 and 14, the bottom mold plate  32  further includes two spaced, transversely extending, side walls  308   a  and  308   b , two spaced, longitudinally extending, side walls  310   a  and  310   b,  a pair of alignment pins  312 , a pair of alignment apertures  314 , four lift apertures  316 , four side lock apertures  318 , two forward slide apertures  320 , two forward lock apertures  322 , and two arms  324 .  
         [0117]    The alignment pins  312  are located diagonally across from each other adjacent to the two longitudinally extending side walls  310   a  and  310   b.  The alignment apertures  314  are defined diagonally across from each other adjacent to the two longitudinally extending side walls  310   a  and  310   b.  The alignment pins  312  and apertures  314  are vertical.  
         [0118]    Referring to FIGS. 4 and 14, the lift apertures  316  extend vertically through the plate adjacent to the two longitudinally extending side walls  310   a - b.  The lift apertures  316  receive the lift pins  170  of the lower elevator assembly  18 . The diameter of the lift apertures  316  is less than the width W of the blocks  166  and greater than the diameter of the upper portion  174  of the pin.  
         [0119]    Referring to FIG. 14, the side lock apertures  318  are defined in the longitudinal side walls  310   a - b  of the bottom plate and extend transversely. The side lock apertures  318  are for engagement of the working station lock assemblies  28 W (as shown in FIG. 6).  
         [0120]    The forward slide apertures  320  are defined through the plate adjacent to the transverse side wall  308   b  and extend vertically. The forward slide apertures  320  are for engagement of slide lock assemblies  28 S (as shown in FIG. 7).  
         [0121]    The forward lock apertures  322  are defined through the plate adjacent sidewall  308   b  and extend vertically. The forward lock apertures  322  are for engagement of the loading station lock assemblies  28 IL and  28 EL (as shown in FIG. 6).  
         [0122]    The arms  324  extend horizontally from the transverse side wall  308   a , and are attached to side wall  308   a  with conventional fasteners. The arms  324  define rear slide apertures  326  vertically therethrough at the free ends. The arms  324  are spaced apart so that the rear slide  6  apertures  326  can be engaged by the slide lock assemblies  28 S (as shown in FIG. 7).  
         [0123]    Referring to FIGS. 4 and 15, the top mold plate  34  further includes two spaced transversely extending side walls  328   a  and  328   b , two spaced longitudinally extending side walls  330   a  and  330   b,  a pair of alignment pins  332 , a pair of alignment apertures  334 , eight lift notches  336 , two sets of side lock apertures  338  and  340 , two forward slide apertures  342 , two rear slide apertures  344 , and two forward lock apertures  346 .  
         [0124]    The alignment pins  332  are located diagonally across from each other and adjacent to the two longitudinally extending side walls  330   a - b.  The alignment apertures  334  are defined diagonally across from each other adjacent to the two longitudinally extending side walls  330   a - b.  The alignment pins  332  and apertures  334  are vertical. Referring to FIGS. 14 and 15, when the top mold plate  34  is inverted over the bottom mold plate  32 , the alignment pins  332  on the top mold plate insert into the alignment apertures  314  of the bottom mold plate  32  and the alignment pins  312  of the bottom mold plate  32  insert into the alignment apertures  334  of the top mold plate  34  to position the mold plates relative to each other.  
         [0125]    One set of four lift notches  336 , as shown, extend vertically, partially through the plate from the upper surface of the plate. These notches  366  are adjacent to the two longitudinally extending side walls  330   a - b.  The other set of four lift notches (not shown) are disposed on the bottom surface of the plate. The lift notches  336  receive the lift pins  170  (shown in FIG. 4) of the lower elevator assembly  18 . The lift notches  336  have a diameter greater than the diameter of the upper portion  74  of the lift pin  170  so that the lift pins are received therein.  
         [0126]    Referring to FIG. 15, outer and inner sets of side lock apertures  338  and  340  are defined in the longitudinal side walls  330   a - b  of the top plate and extend transversely. The side lock apertures  338  and  340  are for engagement of the working station lock assemblies  28 W (as shown in FIG. 6) and the frame lock assemblies  28 F (as shown in FIG. 7) that are transversely oriented.  
         [0127]    The forward slide apertures  342  are defined through the plate adjacent to the transverse side wall  328   b  and extend vertically. The rear slide apertures  344  are defined through the plate adjacent to the transverse side wall  328   a  and extend vertically. The forward and rear slide apertures  342  and  344  are for engagement of slide lock assemblies  28 S (as shown in FIG. 7).  
         [0128]    The forward lock apertures  346  are defined vertically through the plate adjacent to the transverse side wall  328   b . The forward lock apertures  346  are for engagement of the intermediate loading station lock assemblies  28 IL (as shown in FIG. 6). Referring to FIG. 16, the center mold plate  36  further includes two spaced, transversely extending, side walls  348   a  and  348   b , two spaced, longitudinally extending, side walls  350   a  and  350   b,  a set of four alignment apertures  352 , four lift apertures  354 , and two sets of side lock apertures  356  and  358 .  
         [0129]    Referring to FIGS. 14 and 16, the alignment apertures  352  are located in rectangular orientation spaced from each other adjacent to the two longitudinally extending side walls  350   a - b.  The alignment apertures  352  are vertical. When the center plate  36  is disposed between the top and bottom plates  34  and  32 , the alignment apertures  352  receive the respective alignment pins  312  and  332  of the top and bottom plates.  
         [0130]    Referring again to FIGS. 14 and 16, the lift apertures  354  extend vertically through the plate  36  adjacent to the two longitudinally extending side walls  350   a - b.  The lift apertures  354  receive the lift pins  170  of the lower elevator assembly  18 . The diameter of the lift apertures  354  is less than the diameter of the base portion  172  of the lift pin  170  so that the center plate  36  will rest on the shoulder  176 .  
         [0131]    One set of side lock apertures  356  are defined in the longitudinal side walls  350   a - b  of the center plate and extend transversely. The other set of side lock apertures  358  are defined in the transverse side walls  348   a - b  of the center plate and extend longitudinally. The side lock apertures  356  are for engagement of the frame lock assemblies  28 F (as shown in FIG. 11). The side lock apertures  358  are for engagement of the upper elevator lock assemblies  28 UE (as shown in FIG. 9).  
         [0132]    Operation of the molding apparatus will now be discussed. Referring to FIG. 17 (Step  1 ) and FIG. 3, initially the bottom mold plate  32  is located in the end loading station EL on the slide frame  38 , the top mold plate  34  is located in the intermediate loading station IL on the slide frame  38 , and the center mold plate  36  is located in the working station W at an elevated position in the elevator frame  40 .  
         [0133]    The bottom mold plate  32  is held in the end loading station EL by the lock assemblies  28 EL (shown in FIG. 6) engaging the forward lock apertures  322  (shown in FIG. 14). The top mold plate  34  is held in the intermediate loading station IL by the lock assemblies  28 IL (shown in FIG. 6) engaging the forward lock apertures  346  (shown in FIG. 15). The center mold plate  36  is held in the working station W by the lock assemblies  28 UE (shown in FIG. 9) engaging side lock apertures  358 . Referring to FIGS. 9 and 17 (Step  1 ), the lower plate  180  is position in the elevated position and holds the center mold plate  36  in the elevated position. In these positions, outer core material (not shown), such as polybutadiene, is placed in the cavities  304  (as shown in FIG. 4) of the bottom and top mold plates. The material is in the form of preps or preforms. The rotating frame  212  is upright.  
         [0134]    Referring to FIG. 7, the front slide lock assemblies  28 S engage the rear slide apertures  344  (as shown in FIG. 15) of the top mold plate  34  and the forward lock apertures  320  (as shown in FIG. 14) of the bottom mold plate  32 . The sliding assembly  114  is moved toward the elevator frame  40 . As shown in FIG. 17, in Step  2 , the top and bottom plates  34  and  32  are moved at the same time. The top plate  34  comes to rest in the working station W and the bottom plate  32  comes to rest at the intermediate loading station IL.  
         [0135]    As shown in FIGS. 8, 11, and  15 , the lift pins  170  of the lower elevator  18  engage the lower surface lift notches  336  of the top mold plate  34  and the motor  154  via the jack screw  156 , rods  142  and shaft  144  raises the upper plate  140  of the lower elevator  18 . The upper plate  140  is raised (as seen in FIG. 17, Step  3 ) from the lower position to the rotating position where it is aligned with the lower set of frame lock assemblies  28 F of the rotating frame  212 . Once the top mold plate  34  is at the rotating frame  212 , the frame locking assemblies  28 F engage the set of inner side lock apertures  340  to secure the top mold plate  34  to the rotating frame  212  at the rotating position. The upper plate  140  of the lower elevator  18  returns to the lowest position beneath the level of the slide assembly. The slide assembly  16  (as shown in FIG. 7) moves so that the forward slide lock assemblies  28 S are aligned with the forward slide apertures  320  (as shown in FIG. 14) of the bottom mold plate  32 .  
         [0136]    At the same time in Step  3 , the lower plate  180  (as shown in FIG. 9) of the upper elevator  20  moves the center mold plate  34  to the rotating position. Once the center mold plate  34  is aligned with the rotating frame  212 , the upper frame locking assemblies  28 F′ engage the lock apertures  356  (as shown in FIG. 16) of the center mold plate  36  and the locking assemblies  28 UE on the upper elevator disengage the plate. Thereafter, the upper elevator  20  moves the lower plate  180  back to the elevated position.  
         [0137]    As shown in FIG. 17, (Step  4 ) the rotating frame  212  rotates 180° and comes to rest inverted. The center and top mold plates  36  and  34  are rotated together. After this rotation the center plate  36  is beneath the top plate  34  so that the preps in the top mold plate cavities are secured therein. At the same time, the slide lock assemblies  28 S (as shown in FIG. 7) engage the forward slide apertures  320  (FIG. 14) of the bottom mold plate  32  and move the plate  32  into the working station W. Then, the slide assembly  114  (as shown in FIG. 2) moves until the forward lock assemblies  28 S are aligned with the rear lock apertures  326  of the bottom mold plate. Thus, all three plates are vertically aligned, and the center mold plate is between the top and bottom mold plates.  
         [0138]    Referring to FIG. 4, the upper plate  140  of the lower elevator  18  rises so that the lift pins  170  extend through the lift apertures  316  in bottom mold plate  32 . When the lift block  166  engages the lower surface of the bottom mold plate  32 , the bottom mold plate rises with the upper plate  140 . The bottom mold plate  32  is elevated until it is beneath the center mold plate  36  in the rotating position. The alignment pins  312  of the bottom mold plate engage the alignment apertures  352  of the center mold plate and the alignment apertures  332  (as shown in FIG. 14) of top mold plate, thereby bringing all three mold plates into alignment.  
         [0139]    Referring to FIGS. 4 and 11, the rotating frame locking assemblies  28 F and  28 F′ disengage the center and top mold plates  34  and  36  so that these plates rest on the bottom mold plate  32 . Thereafter, the lower elevator upper plate  140  descends (as shown in FIG. 17, Step  5 ) to return the bottom mold plate  34  to the guide blocks  102  (as shown in FIG. 6). Consequently, all three plates descend. The upper plate  140  then descends to the lowest position.  
         [0140]    Now, the assembly is ready for molding. The forward slide assemblies  28 S of the slide (as shown in FIG. 7) engage the rear slide apertures  326  on the bottom mold plate  32  (FIG. 14). The slide plate is moved toward the mold press  30  (as shown in FIG. 3) so that the bottom mold plate and the top and center mold plates thereon are transported onto the guide blocks  296  (as shown in FIG. 13) within the mold press  30 .  
         [0141]    Once the three mold plates are placed into the press  30 , they are heated and compressed. Preferably, the mold plates are heated to a first temperature that makes the polybutadiene material significantly more pliable, but is below the cure activation temperature. Preferably, the temperature is greater than about 150° F., but less that the cure activation temperature. The most preferred temperature is between about 190° F. and 220° F. The mold plates are compressed to a pressure sufficient enough to form hemispheres from the polybutadiene material. Preferably, the mold plates are compressed using a hydraulic preforming pressure of about 230 psi. Using for example, a 28 inch diameter ram for the press that produces 142,000 pounds of force on a mold with 210 cavities, the pressure per cavity is about 675 pounds of force per cavity. However, one of ordinary skill in the art can vary the heat and pressure as necessary. The mold plates are then cooled with cooling water that has a temperature between about 60° F. to 100° F. and preferably the cooling water has a temperature of about 80° F. After molding is complete, the forward slide lock assemblies  28 S (as shown in FIG. 7) engage the rear slide apertures  326  of the bottom mold plate  32  (as shown in FIG. 14) and return the plates to the working station W.  
         [0142]    Referring to FIG. 17 (Step  6 ), and FIGS. 4 and 14- 16 , the upper plate  140  of the lower elevator  18  raises to engage the three mold plates and break the mold plates apart. The working station lock assemblies  28 W and  28 W′, engage the bottom and center mold plate side lock apertures  318  and  338 . The lifting pins  170  insert into the lift pin apertures  316  and  354  of the bottom and center mold plates respectively. The tip of the lift pins  178  engage the notches  336  of the top mold plate  34  and lift the top mold plate  34  off of the center mold plate  36 .  
         [0143]    The working station lock assemblies  28 W release the center plate and the elevator plate  140  continues upward. The lock apertures  356  of the center plate  36  receive the upper portion  174  of the lift pin, but are too small to receive the base portion  172  of the lift pin so that the center plate  36  rests on the shoulder  176  and is raised above the bottom mold plate  32 . The lift apertures  316  of the bottom mold plate  32  receive the base portion  172  of each lift pin and the plate  32  rests on the upper surface  168  of the block  166 . The lock assemblies  28 W′ releases the bottom mold plate.  
         [0144]    The upper plate  140  continues to rise until the top and center mold plates are aligned with the respective frame lock assemblies  28 F and  28 F′ at the rotating position. The lock assemblies  28 F and  28 F′ engage the plates and hold the top plate  34  over the center plate  32 .  
         [0145]    Referring to FIGS. 4 and 6, the upper plate  140  of the lower elevator  18  descends with the bottom mold plate  32  until the bottom mold plate  32  rests on the guide blocks  102 . The upper plate  140  continues to descend to the lowest position. The bottom mold plate  32  contains formed outer core hemispheres in the cavities  304 .  
         [0146]    Referring to FIGS. 7, 14 and  17  (Step  7 ), the slide lock assemblies  28 S engage the forward slide apertures  320  of the bottom mold plate  32  and move it to the intermediate loading station IL. The lock assemblies  28 IL (as shown in FIG. 6) engage the forward lock apertures  322  of the bottom mold plate  32  to hold it in the intermediate station IL. Next in Step  8  (as shown in FIG. 17), the center and top mold plates  36  and  34  are rotated together 180° by the rotating frame  212  until the top mold plate  34  is between the center and bottom mold plates  32  and  36 .  
         [0147]    Referring to FIGS. 4, 9,  11 ,  16 , and  18  (Step  9 ), the lower plate  180  of the upper elevator  20  descends and the lock assemblies  28 UE engage the side lock apertures  358  of the center plate  36 . The lock assemblies  28 F of the rotating frame  212  disengage from the center mold plate  36 . The lower plate  180  is moved by the servo-motor  200 , jack screw  202 , rods  186  and center  188  shaft so that raises the center mold plate  36  to the elevated position again.  
         [0148]    Before reaching the elevated position, the lower plate  180  stops so that the tops of the protrusions  307  (as shown in FIG. 4) on the upper surface of the center mold plate  36  are aligned with the light source  24  and sensors  26  (as shown in FIG. 3). The light source  24  generates a light. If the light is not received by the sensors  26 , then some elastomeric material is on at least one of the protrusions and an incomplete circuit exists. A signal is sent to the controls and/or operator that the quality of the shells is not satisfactory. If the light is received by the sensors  26 , then the cup quality is satisfactory and the circuit is complete. The lower plate  180  continues to rise until the tops of the protrusions  307  on the lower surface of the center mold plate are aligned with the light source  24  and sensors  26 . These protrusions are similarly checked for elastomeric material. Simultaneously, the inner cores  13  (as shown in FIGS. 1 and 2) are placed in the hemispheres in the bottom mold plate  32  in the intermediate loading position IL.  
         [0149]    Referring to FIGS. 7 and 18 (Step  10 ), the rotating frame  212  rotates the top mold plate  34  at 180°. The outer core hemispheres contained in the cavities of the top mold plate remain in the cavities due to the temperature difference between the core material and the plate  34 . Depending on the material used the temperature of the core material can be greater than or less than the temperature of the plate and produce the desired result. In this embodiment, the temperature of the core material is lower than the temperature of the plate. At the same time, the slide lock assemblies  28 S (as shown in FIG. 7) engage the bottom mold plate forward slide apertures  320  and move the bottom mold plate into the working station W.  
         [0150]    Referring to FIGS. 4, 6, and  18  (Step  11 ), the lower elevator  18  raises the bottom mold plate  32  to the rotating frame  212 , in the same manner as previously described in Step  3 . The frame locking assemblies  28 F release the top mold plate  34 . The tip  178  of the lift pins engage the notches  336  of the top mold plate. The upper plate  140  of the lower elevator  18  lowers the bottom and top mold plates  32  and  34  to the guide blocks  102 . The lower plate then descends to the lowest position.  
         [0151]    Turning to FIGS. 7 and 15, the cores are ready for molding. The forward locking assemblies of the slide  28 S engage the rear slide apertures  326  on the bottom mold plate  32 . The slide  114  is moved forward so that the bottom mold plate and the top mold plate thereon is transported onto the guide blocks  296  (as shown in FIG. 13) within the molding press  30 .  
         [0152]    Once the two mold plates are placed into the press  30 , they are heated and compressed. This time, the bottom and top mold plates are heated to a temperature above the cure activation temperature of the polybutadiene hemispheres. Preferably, the mold plates are heated to a temperature of greater than about 290° F. Preferably, the mold plates are compressed using a hydraulic preforming pressure of about 2000 psi. Using for example, a 28 inch diameter ram for the press that produces 615.5 tons of force on a mold with  210  cavities, the pressure per cavity is about 6000 pounds of force per cavity. However, one of ordinary skill in the art can vary the pressure.  
         [0153]    After molding is complete, the forward slide lock assemblies  28 S (as shown in FIG. 7) engage the rear lock apertures  326  (as shown in FIG. 14) of the bottom mold plate  32  and return the plates to the working station W.  
         [0154]    Referring to FIGS. 4 and 18 (Step  12 ), the upper plate  140  of the lower elevator  18  raises and the lift pins  170  separate the top mold plate  34  from the bottom mold plate  32  and both plates are lifted to the rotating frame  212 , as previously described. The top mold plate  34  is retained in the rotating frame  52  in the same manner as described before. Thereafter, the upper plate  140  of the lower elevator descends with the bottom mold plate  34  and the finished cores therein.  
         [0155]    Referring to FIG. 18 (Step  13 ), and FIGS. 4, 7, and  14 , the rotating frame  212  with the top mold plate  34  retained there rotates the top mold plate  34  180° so that the cavities  304  in the top mold plate are facing upwardly. At the same time, the slide lock assemblies  28 S engage the forward slide apertures  320  of the bottom mold plate and the slide assembly  114  moves the bottom mold plate  32  to the intermediate loading station IL.  
         [0156]    Turning to FIGS. 4, 6,  15  and  18  (Step  14 ), the upper plate  140  of the lower elevator  18  raises and the lift pins  170  engage the notches  336  of the top mold plate  34 . The rotating frame locking assemblies  28 F then release the top mold plate. The upper plate  140  descends with the top mold plate  34  until the top mold plate is on the guide blocks  102  in the working station W. The upper plate  140  continues to descend to the lowest position.  
         [0157]    Referring to FIGS. 7, 14,  15 , and  18  (Step  15 ), forward slide lock assemblies  28 S engage the rear slide apertures  344  of the top plate  34 , and the rear slide lock assemblies  28 S′ engage the forward slide apertures  320  of the bottom plate  32 . As the slide assembly  114  moves toward the first end  38   a  of the slide frame  38 , it moves the top and bottom mold plates  34  and  32 . When the slide assembly comes to rest, the top mold plate  34  is in the intermediate loading station IL and the bottom mold plate  32  is in the end loading station EL. The locking assemblies  28 IL and  28 EL (as shown in FIG. 6) engage the lock apertures  346  and  322 , of the top and bottom mold plates respectively. The two-piece cores are removed from the bottom mold plate. Covers are formed on the cores, as discussed above. The process can be repeated to form additional cores.  
         [0158]    While it is apparent that the illustrative embodiments of the invention herein disclosed fulfill the objectives stated above, it will be appreciated that numerous modifications and other embodiments may be devised by those skilled in the art, for example, a series of progressively larger diameter shells can be formed and joined by the methods disclosed. This method can also be used to form additional intermediate layers. This method can also be used to form multi-layered cover layers. This method can also be used with a center plate that is moved horizontally from an initial position unaligned with the top plate to a position substantially vertically aligned with the top plate prior to rotating these plates together. The movements of the plates can be varied to achieve the results of the present invention. Therefore, it will be understood that the appended claims are intended to cover all such modifications and embodiments which come within the spirit and scope of the present invention.