JP4084064B2 - Selectively weighted golf balls - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates generally to golf balls, and more particularly to selectively weighted golf balls.
[0002]
[Technical background]
Conventional golf balls have been designed to provide special competitive characteristics. These characteristics typically include the initial speed, compressibility and spin of the golf ball and can be optimized for various types of players. For example, some players prefer a ball with a high spin rate to control the ball's flight and stop the golf ball on the green. However, this type of ball usually does not give the maximum flight distance. Other players prefer balls that exhibit low spin speed and high resiliency to maximize flight distance.
Early solid golf balls generally consisted of a hard core and a hard cover. Generally, when the golf ball includes a soft core and a hard cover, the ball has a low spin rate. When the golf ball includes a hard core and a hard cover, the ball exhibits a very high resiliency to obtain flight distance, but exhibits a “hard” feel and is difficult to control on the green. Further, if the golf ball includes a hard core and a soft cover, the ball will have a high spin rate. The most recently developed solid ball is composed of a core, at least one intermediate layer and a cover. The intermediate layer improves the playing characteristics of the solid ball and can be made of a thermoset or thermoplastic material.
[0003]
Typically, a solid golf ball core is spherical and solid. In an effort to improve the spin rate of the ball, the mass distribution within the golf ball was changed by concentrating the mass in the spherical inner core or mantle near the ball surface. Accordingly, it is desirable to provide a golf ball with a symmetric non-spherical mass distribution that provides unique spin rate characteristics.
Some patents are directed to an inner core that has been modified by non-spherical features such as holes or protrusions.
US Pat. No. 720,852 to Smith discloses an inner core having small solid protrusions protruding from the core. The core is housed in a rubber layer, and the core has small solid protrusions protruding therefrom. A silk layer is wrapped around this and then the ball is housed in an outer cover. These non-spherical core protrusions anchor the rubber and silk layers and increase the resiliency of the ball as a whole, but do not exhibit a mass distribution function.
[0004]
US Pat. No. 1,524,171 to Chatfield discloses a core with a hollow spherical center that supports a cylindrical solid lug. A spherical casing surrounds and is in contact with the tip of the lug. The lug and casing are designed such that the casing compresses the lug within the finished ball. A fluid or wrapped rubber band occupies the space around the lug between the spherical center and the casing. The non-spherical lug allows accurate placement of the center by facilitating uniform and spherical winding of the rubber band around the center, but has a mass distribution function Absent. An outer shell surrounds the casing.
UK Patent Application 2,162,072 to Slater discloses a golf ball having a non-spherical inner core, which includes a solid support member or strut that branches off from a common center. . The struts generally form a cubic, tetrahedral or octahedral core. The struts position the inner core symmetrically within the mold cavity but do not perform mass distribution. The partial core is molded around the inner core, and a cover is formed thereon. The inner and outer cores are formed from the same or similar material.
[0005]
U.S. Pat.No. 5,480,143 to McMurry discloses a substantially spherical practice ball that includes members that are orthogonal to each other, the members connecting a plurality of them together. Have a wall. These walls increase the resistance on the ball and, as a result, allow for the use of a smaller playing area.
U.S. Pat.No. 5,836,834 to Masutani et al. Is a two-piece including a two-layer solid core composed of a low hardness inner core and a high hardness outer core joined around the inner core. Or a three-piece golf ball is disclosed. Protrusions are formed on the inner surface of the high hardness outer core such that they extend substantially along the normal direction. On the other hand, grooves corresponding to these protrusions are formed on the outer surface of the low hardness inner core. The low hardness inner core and the high hardness outer core are joined together such that the protrusion is inserted into the groove.
Other patents disclose adding peripheral mass to the golf ball to increase its moment of inertia. U.S. Pat. No. 5,984,806 discloses a golf ball having a visible peripheral mass provided on a spherical inner cover.
However, these patents do not disclose golf balls having structures as described herein that provide the improved golf balls of the present invention.
[0006]
[Problems to be solved by the invention]
It is an object of the present invention to provide a golf ball having a core geometry designed to provide improved playing characteristics, such as spin speed.
It is an object of the present invention to provide a golf ball having an inner core that further includes a preformed and selectively weighted insert.
The present invention further provides a golf ball including a pre-molded, selectively weighted insert suitable for having an outer core molded over the inner core.
[0007]
[Means for Solving the Problems]
Accordingly, the golf ball of the present invention comprises a preformed and selectively weighted inner core insert, an outer core formed on the inner core insert, and a cover provided around the outer core. It is characterized by including. According to one aspect of the invention, the preformed insert includes a high specific gravity central hob and a low specific gravity external element, resulting in a ball of low moment of inertia and high spin speed. According to another aspect of the invention, the preformed insert includes a high specific gravity external element that produces a ball of high moment of inertia and low spin rate.
According to a further aspect of the invention, the inner core insert includes an outer pocket thereon. These pockets are suitable for receiving a portion of the outer core material. When the outer core material has a high specific gravity, the golf ball has a high moment of inertia, and when the outer core material has a low specific gravity, the golf ball has a low moment of inertia.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in more detail below with reference to the accompanying drawings which form a part of this specification and should be read in combination with this specification. In the accompanying drawings, like reference numerals are used to indicate like parts in the various drawings.
Referring to FIG. 1, the golf ball 5 of the present invention includes a cover 25 that is substantially spherical and has a number of dimples 27 formed on the outer surface. 2-4, the golf ball 5 includes an inner core 10, outer cores 15 and 20, and a cover 25 (shown without dimples). The inner core 10 includes a three-dimensional outer surface, a center C, a center portion 30, and a plurality of protrusions 35. The central portion 30 and the protrusion 35 are preferably integrally formed so that the inner core is an integral part. Preferably, the inner core 10 is a pre-molded insert that can be overlaid with other materials to form the core of the golf ball.
Referring to FIG. 4, the outer surface 28 of the inner core 10 is defined by a radial distance from the center C. At least two radial distances around the outer surface, r_cpAnd r_pIs different. The central portion 30 of the inner core 10 is indicated by an arrow r_cpThe radius extends from the core center C to the outer surface of the central portion. The central portion 30 is solid in this embodiment, but may be hollow as discussed below.
[0009]
With reference to FIGS. 3 and 4, each of the protrusions 35 extends radially outward from the central portion 30 and is spaced from one another to define a gap 40 therebetween. The protrusion 35 is shaped so that the inner core 10 is substantially symmetrical. Each projection 35 has a large free end 45 and has a substantially conical shape. Each free end 45 has an open groove 50. Each protrusion is an arrow r_pThe radius extends from the core center C to the outer surface 28 at the free end 45. Radius r of this protrusion_pIs the radius r of the central portion_cpIs different.
Referring to FIG. 3, each groove 50 is formed by three integrated side walls 55. Each side wall 55 is shaped on a flat quadrant. This quadrant includes two straight ends 60 joined by a curved end 65. In each projection 35, each of the side walls 55 is joined at the linear end 60. The end 65 with the curvature of each protrusion allows the inner core to have a spherical contour.
[0010]
In relation to the three-dimensional Cartesian coordinate system, there are x, y, and z axes that are orthogonal to each other, forming eight octants. There are eight projections 35, one for each octant of this coordinate system. As a result, each of the protrusions 35 forms an octant of the skeletal sphere. Thus, the inner core is symmetric. The gap 40 includes three orthogonal concentric rings 70._x, 70_yAnd 70_zIs defined. The subscript number 70 indicates the central axis that the ring bounds.
Returning to FIGS. 2 and 4, the outer core includes a first portion 15 and a second portion 20. The first portion 15 fills the gap 40 around the protrusion 35 and is disposed between the side walls 55 of adjacent protrusions 35. The diameter of the core, including the inner and outer cores, has a diameter ranging from about 2.54 cm (1.00 in) to about 4.17 cm (1.64 in) for a ball having a diameter of about 4.27 cm (1.68 in). It is preferable to have it.
[0011]
The second portion 20 fills the groove 50 of each protrusion 35 and is provided between the side walls 55 of the single protrusion 35. The outer core terminates the free end 45 of each projection 35 at the same height. The outer core has a substantially spherical outer surface. The cover 25 is formed around the inner core 10 and the outer core portions 15 and 20. Accordingly, both the inner and outer cores are in contact with the cover.
Referring to FIG. 2, golf ball formation begins with the manufacture of the inner core 10. As discussed above, the inner core 10 is preferably preformed as an insert. The inner core 10, outer core portions 15 and 20, and the cover 25 are manufactured by compression molding, injection molding and casting. These methods for producing such cores and covers are well known in the art.
[0012]
These inner and outer core materials preferably have substantially different material properties so that there is a predetermined relationship between the inner and outer cores, and the desired athletic properties of the ball, For example, the spin rate of the ball is achieved. For example, the inner core 10 can be manufactured from a low specific gravity material having a specific gravity of less than 0.9, preferably less than 0.8. On the other hand, the outer core portion 20 is preferably made of a high specific gravity material having a specific gravity preferably greater than 1.2, more preferably greater than 1.5, and most preferably greater than 1.8. Since the outer core portion 20 has a higher density and is located more radially inward than the inner core 10, the ball 5 has a high moment of inertia and a low spin rate.
[0013]
As with the inner core 10, the outer core portion 15 can be made of a low specific gravity material. In this example, the outer core 20 has the greatest specific gravity and contributes most to the high moment of inertia of the ball. On the other hand, the outer core portion 15 can have the same specific gravity as the outer core 20 as long as the total mass of the ball does not exceed the USGA nominal mass of about 45.9 g (1.62 oz). Alternatively, as shown in FIG. 6, the outer core portion 15 can be divided into two bands 15a and 15b. Preferably, zone 15b has a high specific gravity greater than 1.2, more preferably greater than 1.5, and most preferably greater than 1.8. The band 15b can have a specific gravity similar to that of the inner core 10. Similarly, the outer core portion 20 can have a high specific gravity band and a low specific gravity band. Alternatively, the protrusions 35 of the inner core 10 can be made of a high specific gravity material, while the remainder of the inner core 10 is made of a low specific gravity material so as to have a high moment of inertia.
[0014]
Further, to distribute mass towards the outer core, the inner core 10 can include a hollow cavity 72, as shown in FIG. The cavity 72 of the inner core 10 can be filled with a low density liquid such as inorganic or lubricating oil, vegetable oil, methanol, ethanol, ammonia, etc., as long as the selected liquid does not react with surrounding materials.
On the other hand, to produce a low moment of inertia or high spin speed ball, the central portion 30 of the inner core 10 can be made of a high specific gravity material, while the protrusion 35, the outer core portion 15 or the core portion 20 or these three types Any combination of these parts can be made of a low specific gravity material. Preferably, the central portion 30 can have a specific gravity greater than 1.2, more preferably greater than 1.5, and most preferably greater than 1.8. Preferably, the low specific gravity material has a specific gravity of less than 0.9 and more preferably less than 0.8. The central portion 30 can also be preferably filled with a non-reactive high density liquid such as glycerin or carbon tetrachloride. As shown in FIG. 8, the cavity 72 of the central portion 30 has an envelope 74 that contains a fluid 76. Advantageously, the envelope 74 can be made of a material capable of containing and isolating the reactive liquid so that it can be used.
[0015]
Suitable fluids that can be used in terms of specific gravity include air, aqueous solutions, liquids, gels, foams, hot melts, other fluid materials, or combinations thereof. Examples of suitable liquids include aqueous salt solutions, corn syrup, aqueous salt solutions and corn syrup, glycol and water or oil. The liquid may further comprise a paste, a colloidal suspension, such as clay, barite, carbon black, or a salt in a water / glycol mixture dispersed in water or other liquid. Examples of suitable gels include gels comprising water gelatin gels, hydrogels, water / methylcellulose gels, and materials based on styrene-butadiene-styrene rubber and copolymer rubbers such as paraffinic and / or naphthenic oils. To do. Examples of suitable melts include waxes and hot melts. Hot melt is a material that is solid at or near normal room temperature but becomes liquid at high temperatures. A high melting point is desirable because the liquid core is heated to a high temperature during molding of the inner core, outer core, and the cover. Alternatively, the liquid can be a selectively reactive liquid system that combines to form a solid. Examples of suitable reactive liquids are silicate gels, agar gels, peroxide cured polyester resins, two-part epoxy resin systems, peroxide cured liquid polybutadiene rubber compositions, reactive polyurethanes, silicones and polyesters.
[0016]
Suitable inner and outer core materials include thermosetting resins such as rubber, polybutadiene, polyisoprene; thermoplastic resins such as ionomer resins, polyamides or polyesters; or thermoplastic elastomers. Suitable thermoplastic elastomers are commercially available from Pebax (Pebax, commercially available from Elf-Atochem, DuPont, various manufacturers and Shell, respectively.^TM), Hytrel^TM), Thermoplastic urethane, and Kraton^TM). The inner and outer core materials can also be castable materials. Suitable castable materials include urethane, polyurea, epoxy and silicone. Other suitable core and cover materials are also described in US Pat. No. 5,919,100. The entire contents of the patent are incorporated herein by reference.
More specifically, the low specific gravity material can be made of a plastic polymer in which a density reducing filler such as a hollow sphere or a microsphere is embedded, or the density can be reduced by foaming or the like. In addition, suitable materials include nucleated reaction injection molded polyurethane or polyurea, where a gas, typically nitrogen gas, is essentially added before the components are injected into a closed mold. Polyurethane is typically blown into at least one component of the prepolymer. All reactions occur within the mold, giving a cured polymer with reduced specific gravity. These materials are called reaction injection molding (RIM) materials. On the other hand, the high specific gravity layer can be made from a high density metal or from a high density metal powder encased in a polymer binder. High density metals such as steel, tungsten, lead, brass, bronze, copper, nickel, molybdenum or alloys thereof can be used.
[0017]
The cover 25 should be high toughness and high cut resistance and should be selected from materials conventionally used as golf ball covers based on predetermined performance characteristics. This cover can be formed of one or more layers, such as the ball shown in FIG. Cover materials such as ionomer resins, blends of ionomer resins, thermoplastic or thermosetting urethanes, and balata can be used as is known in the art.
In another embodiment of the present invention, the inner core 10 itself is pre-molded and selectively weighted. Preferably, this preformed and selectively weighted structure is a solid, unitary element for ease of manufacture. However, the present invention is not limited to this. For example, as described above, the protrusion 35 can be made of a material different from that of the core 30 to achieve a predetermined mass distribution. This selectively weighted structure can be overmolded with the outer core material in any suitable manner to produce the golf ball 5 core. Some preferred manufacturing methods are injection molding, compression molding, reactive injection molding and casting. This preformed insert in the present invention can concentrate the mass of the ball at a discontinuous location near the center of the ball or the outer surface of the ball. These discontinuous positions are arranged symmetrically with respect to the outer surface of the ball so as not to affect the aerodynamic and rotational properties of the ball. The core and other mantle layers surround the preformed insert, so that they completely surround the preformed insert or most of the insert, but some part of the surface By aligning, the portions can be exposed or visible on the final surface of the ball.
[0018]
Referring to FIG. 9, another embodiment of the inner core is shown. The inner core 78 includes a spherical central portion and a plurality of protrusions 80 extending radially outward from the central portion. These protrusions 80 include a base and a free end of the point. These protrusions 80 are preferably conical, i.e. tapered from the base towards the free end of the peak. These protrusions 80 can also have other forms such as polygons. Examples of polygons include triangles, pentagons and hexagons.
Inner core 78 is an example of the preformed insert of the present invention, which provides a ball with a high moment of inertia and a low spin rate. Preferably, the protrusions 80 that protrude from the surface 82 are made of a high specific gravity material, as described above, and the inner core 78 can be solid or filled with a low density material or liquid. More preferably, the spherical surface 82 of the core 78 is made from the same material as the protrusions 80. In this embodiment, the spherical surface 82 and the protrusions 80 are placed near the surface of the ball to maximize the moment of inertia of the ball.
[0019]
FIGS. 10a, b, c and d show another embodiment of the preformed insert according to the invention, which gives a ball with a high moment of inertia. An example of a ball-rod insert is shown in FIG. Preferably, the insert 84 is made of a high density material. Since the ball 86 is considerably larger than the rod 88 and is located further in the radial direction from the golf ball than the rod 88, the ball 86 imparts a higher moment of inertia to the golf ball. Advantageously, the ball 86 and the rod 88 are preferably made of the same material, thus simplifying the manufacturing process. In order to further increase the moment of inertia, the rod 88 can be hollow. Alternatively, the hollow rod 88 can be filled with a low density fluid, or the rod 88 can be made of a low density material or filled with a low density filler.
[0020]
Similarly, in order to further increase the moment of inertia, the ball 88 has a mushroom-shaped structure as shown in FIG. 10b or an anchor structure as shown in FIG. 10c. Can be bigger. The above discussion regarding the ball-rod insert 84 also applies to these mushroom type inserts 90 and anchor type inserts 92. FIG. 10d shows another variation of the ball-rod structure. This web-loaded ball-rod insert 94 includes a plurality of balls 88 connected together by web-shaped legs 96. Advantageously, the mass of these balls 88 and web leg 96 is distributed towards the outer periphery of the golf ball to maximize its moment of inertia. It is also possible to enlarge the ball 88 of the insert 94 to have a mushroom type or anchor type shape.
[0021]
FIGS. 11a-e show low moment of inertia aspects for an inner core comprising a preformed insert according to the invention. FIG. 11a is substantially the same as the ball-rod insert shown in FIG. 10a. The preformed insert 98 includes a plurality of low specific gravity balls 100 connected to a high specific gravity hob 104 by rods 102. The hob 104 preferably has a specific gravity that is significantly higher than the specific gravity of the ball 100. Suitable high and low specific gravity materials are discussed above. Preferably, the rod 102 is also made of a low specific gravity material. Alternatively, the ball 100 or the rod 102 or both can be hollow. The insert 98 can also have a mushroom shape or an anchor shape. The high specific gravity insert 106 shown in FIG. 11b is substantially the same as the insert shown in FIG. 10d. However, the ball 108 is made of a low specific gravity material. Ball 108 and web-formed leg 110 define a center 112. Center 112 is suitable for receiving high specific gravity elements such as metal ball bearings or other heavy objects. Alternatively, the center 112 can be filled with a high specific gravity moldable material. The ball 108 can also be hollow. The web-loaded leg 110 preferably centers the ball bearing and maintains it in place during the molding process. Alternatively, the insert 106 can also have a mushroom or anchor shape.
[0022]
FIG. 11c shows a hob-rod insert 114, which is similar to the insert 98 of FIG. 11a, but the insert 114 has a hob 116 and a rod 118 but is provided at the end of the rod 118. Does not include low specific gravity balls. The insert 114 is preferably made of a high specific gravity material as described above.
FIG. 11d shows the insert 120, which includes a high specific gravity center 122 surrounded by a plurality of rings 124. FIG. The ring 124 serves to position and center the insert 120 within the mold cavity. Similarly, the insert 126 shown in e of FIG. 11 has a high density hob 128 surrounded by a plurality of centering pins 130 extending in the radial direction.
[0023]
In yet another aspect of the present invention, FIGS. 12a-c show another embodiment of the preformed insert as a continuous structure with a chamber, which can be solid, hollow or partially filled. An aspect is shown. As shown in FIG. 12a, the insert 132 includes a shell 133 that includes an opening 134 on its surface. A core material can be molded around the open shell 133 and the material can enter the shell through the opening 134. The insert 132 can be made of a low specific gravity material or can be hollow, and the core material can be made of a high specific gravity material to provide a ball of low moment of inertia. On the other hand, the insert 132 can be made of a high specific gravity material, and the core material can be made of a low specific gravity material to provide a ball of high moment of inertia. Alternatively, as shown in FIG. 12b, the insert 132 can include a chamber 136 that is completely or partially filled with a high specific gravity material to obtain a weighted ball at the periphery. On the other hand, the insert 132 shown in FIG. 12 c can have a high density hob 138 located in the center of the open shell 133. The hob 138 can be made of a high specific gravity material, such as a metal ball bearing, and the shell 133 can be made of a low specific gravity material, or it can be hollow. Preferably, the shell 133 can be sized and dimensioned so that it can be placed near the cover 25 of the golf ball 5.
[0024]
  Further, the balls 86, 100, 108, the mushroom and anchor type heads and chambers 136, and the hobs 104, 116, 122, 128 and 138 and the center 112 shown in FIGS. The position can be maximized when these structures are positioned with respect to the center of gravity radius of the ball. The centroid radius is the radial distance from the center of the ball and, as a result of mass redistribution, the moment of inertia at this centroid radius is , Turn from increase to decrease. In other words, if more ball weight or mass is redistributed to the volume of the ball from its center to the radius of the center of gravity, the moment of inertia is reduced, resulting in a high spin ball. If more ball weight or mass is redistributed from its center of gravity radius to the outer cover volume, the moment of inertia increases, resulting in a low spin ball. This center of gravity radius is filed on March 23, 2001 and is entitled "Golf Ball and a Method for Controlling the Spin Rate of Same".09/815753Pending patent applications with(US Patent No. 6494795 No., JP 2002-325863 )Are described in detail. The entire contents of this patent application are incorporated herein by reference.
[0025]
Here, the balls 86, 100, 108, the mushroom and anchor type heads, and the chamber 136 are disposed between the cover of the ball and the center of gravity radius, and the hobs 104, 116, 122, 128 and 138, and It is advantageous to place the chamber 112 between the center of the ball and the radius of the center of gravity.
Furthermore, although only six types of balls 86, 100, 108, six types of mushroom-type and anchor-type heads and four types of chambers 112 are shown in the drawing, the preformed insert 10 may be any number of balls, Mushroom-type and anchor-type heads and chambers can be provided as long as they are arranged symmetrically on the golf ball.
While it will be appreciated that the exemplary embodiments of the invention described herein will meet the above objectives, it will be apparent that many variations and embodiments can be devised by those skilled in the art. One such modification is that the outer surface may be aligned with or extend beyond the free end of the inner surface. Accordingly, the appended claims should be construed to include all such modifications and embodiments that fall within the spirit and scope of the present invention.
[Brief description of the drawings]
FIG. 1 is a side view of a golf ball of the present invention.
2 is a cross-sectional view of the golf ball of the present invention taken along line 2-2 of FIG.
3 is a side view showing an inner core of the golf ball shown in FIG. 2. FIG.
4 is a plan view taken along arrow 4 of FIG. 3 showing the inner core of the present invention.
FIG. 5 is a cross-sectional view of the various embodiments shown in FIGS.
6 is a cross-sectional view of the various embodiments shown in FIGS.
7 is a cross-sectional view of the various embodiments shown in FIGS.
FIG. 8 is a cross-sectional view of the various embodiments shown in FIGS.
FIG. 9 is a side view of another embodiment of an inner core according to the present invention.
FIG. 10a is a side view of an inner core according to the present invention for other aspects.
FIG. 10b is a side view of an inner core according to the present invention in relation to other aspects.
FIG. 10c is a side view of the inner core according to the present invention in other aspects.
FIG. 10d is a side view of an inner core according to the present invention in relation to other aspects.
FIG. 11a is a side view of yet another embodiment of an inner core according to the present invention.
FIG. 11b is a side view of yet another embodiment of the inner core according to the present invention.
FIG. 11c is a side view of yet another embodiment of the inner core according to the present invention.
FIG. 11d is a side view of yet another embodiment of an inner core according to the present invention.
FIG. 11e is a side view of yet another embodiment of an inner core according to the present invention.
FIG. 12a is a side view of an inner core according to the present invention relating to another embodiment, a cross-sectional view relating to a modification of the embodiment shown in FIG. 12a, and another embodiment of the embodiment shown in FIG. It is sectional drawing in connection with a change.
FIG. 12b is a side view of the inner core according to the present invention relating to another embodiment, a cross-sectional view relating to a modification of the embodiment shown in FIG. 12a, and another embodiment of the embodiment shown in FIG. It is sectional drawing in connection with a change.
FIG. 12c is a side view of the inner core according to the present invention relating to another embodiment, a cross-sectional view relating to a modification of the embodiment shown in FIG. 12a and another embodiment of the embodiment shown in FIG. It is sectional drawing in connection with a change.
[Explanation of symbols]
5 ... Golf ball; 10, 78 ... Internal core; 15, 20 ... External core; 25 ... Cover; 27 ... Dimple; 28 ... 3D outer surface; 30 ... Central part; ... Projection; 40 ... Gap; 45 ... Free end; 50 ... Open groove; 55 ... Integrated side wall; 60 ... Linear end; 65 ... End with curvature; Hollow cavity; 74 ... Envelope; 76 ... Fluid; 84, 90, 92, 98, 106, 114 ... Insert; 86, 100, 108 ... Ball; 88, 102, 118 ... Rod; 104, 116 , 122, 128, 138... Hob; 110... Leg with web; 112... Center; 133 ... Shell;

Claims (24)

A preformed and selectively weighted inner core insert, an outer core formed on the inner core insert, and a cover provided around the outer core;
The insert includes a high specific gravity hob and a low specific gravity external element;
The high specific gravity hob has a specific gravity greater than 1.8;
A golf ball characterized in that the low specific gravity external element has a specific gravity of less than 0.8.   The golf ball of claim 1, wherein the outer element includes a plurality of balls arranged symmetrically with respect to the cover.   The golf ball of claim 1, wherein the outer element includes a plurality of mushroom shaped heads disposed symmetrically with respect to the cover.   The golf ball of claim 1, wherein the outer element includes a plurality of anchored heads disposed symmetrically with respect to the cover.   The golf ball of claim 1, wherein the external element is connected to the hob by a corresponding rod.   The golf ball of claim 1, wherein the external element is hollow.   The golf ball according to claim 5, wherein the rod is hollow.   The golf ball of claim 1, wherein the outer elements are connected together by web-like legs.   The golf ball of claim 5, wherein the external element is hollow.   The golf ball of claim 8, wherein the web-bearing leg aligns and centers the hob.   The golf ball of claim 1, wherein the external element includes a plurality of positioning rings provided on the hob.   The golf ball of claim 1, wherein the external element includes a plurality of locating pins provided on the hob.   The golf ball of claim 1, wherein the insert defines a hollow cavity.   The golf ball of claim 13, wherein the hollow cavity includes an envelope.   The golf ball of claim 13, wherein the cavity is filled with a fluid.   The golf ball of claim 15, wherein the fluid is a high specific gravity liquid. The golf ball of claim 15 , wherein the fluid is a low specific gravity liquid.   The golf ball of claim 1, wherein the insert includes a plurality of radially extending protrusions, and the specific gravity of the protrusions preferably exceeds 1.2.   The golf ball of claim 18, wherein the specific gravity of the protrusion exceeds 1.5.   The golf ball of claim 19, wherein the specific gravity of the protrusion exceeds 1.8.   The golf ball of claim 18, wherein the protrusion includes a plurality of pyramidal elements and the pyramidal elements are disposed proximate to the cover.   The golf ball of claim 1, wherein the insert is an open shell including at least one opening, and the outer core material is molded over the shell and penetrates into the shell.   The golf ball of claim 22, wherein the open shell includes a plurality of high specific gravity chambers disposed symmetrically with respect to the cover, wherein the specific gravity of the chamber exceeds 1.2.   The golf ball of claim 22, wherein a high specific gravity hob is provided in the open shell, and the specific gravity of the hob exceeds 1.2.

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