Abstract: Golf club heads (e.g. drivers, fairway woods, wood-type hybrid clubs, or the like) according to at least some example aspects of this invention include a striking face and a rear portion opposite the striking face, the rear portion defining an opening to an interior cavity. A rear body member configured to be inserted into the opening is engaged with the rear portion of the club head. The rear body member may include multiple rear body parts that may be removable and/or interchangeable to permit flexibility in controlling the weight distribution of the golf club head.

Abstract: Multi-piece golf balls containing a multi-layered core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, an intermediate core layer, and a surrounding outer core layer. The layers of the core structure may have different hardness gradients. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof dispersed in a thermoset polymeric matrix. The intermediate core layer is preferably formed from a first thermoplastic composition such as an ethylene acid copolymer ionomer resin; and the outer core layer is preferably formed from a second thermoplastic composition. The resulting ball has high resiliency and good spin control.

Abstract: In a golf ball having a two-layer core consisting of an inner core layer and an outer core layer and a cover of one or more layer, the inner core layer and outer core layer are each formed of a rubber composition made up primarily of a base rubber, the inner core layer has a diameter of not more than 30 mm; and the core has specific hardness ratios (JIS-C hardness/Shore D hardness) at specific points on the cross-section thereof. This golf ball has a reduced spin rate on full shots with a driver and middle irons, thus imparting to an excellent flight performance, and moreover has a good controllability in the short game on approach shots, making it ideal as a golf ball for professional golfers and mid- and high-level amateur golfers.

Abstract: A golf club head comprises a body and at least one self-extracting pressed weight assembly. The body comprises a face plate positioned at a forward portion of the golf club head, a sole positioned at a bottom portion of the golf club head, a crown positioned at a top portion of the golf club head and a skirt positioned around a periphery of the golf club head between the sole and the crown. The body defines an interior cavity. The weight assembly comprises at least three components and is configured for a press fit engagement with the golf club head. The assembly has a drive portion and a threaded portion.

Abstract: Multi-piece golf balls containing a multi-layered core structure are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, an intermediate core layer, and a surrounding outer core layer. The layers of the core structure may have different hardness gradients. In one preferred embodiment, each core layer has a positive hardness gradient. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and alloys thereof. The intermediate core layer is preferably formed from a thermoset composition such as polybutadiene rubber, and the outer core layer is preferably formed from a thermoplastic composition such as an ethylene acid copolymer. The resulting ball has high resiliency and good spin control.

Abstract: Embodiments of a golf club head having a body comprising a first material and a strike face comprising a second material, wherein the density of the first material is greater than the density of the second material, and the ratio of the density of the first material to the density of the second material is greater than or equal to approximately 1.7 are described herein.

Abstract: A forged golf club face has a continuous outer layer of a first material encasing at least one inner layer made of second material. The materials may have differing properties, such as Young's Modulus, density, and strength properties, among others. By incorporating the different materials into the outer layer and the inner layer, the coefficient of restitution (COR) of the golf club face is improved without sacrificing durability. The club face is forged from a pre-formed billet having at least one monolithically encased inner layer.

Abstract: Multi-layered golf balls having a core, intermediate layer, and cover are provided. The ball includes a non-foamed inner core (center) made of a thermoplastic or thermoset composition such as polybutadiene rubber. An intermediate layer comprising a foamed composition, such as polyurethane foam, is disposed about the inner core. The foamed intermediate layer may have a specific gravity gradient within the layer, wherein the outer surface specific gravity is greater than the midpoint specific gravity. Ball constructions having two intermediate layers, wherein at least one layer is a foamed layer can be made. A cover having at least one layer is disposed about the intermediate layer.

Abstract: A golf ball comprising a core comprising an inner core center and an outer core layer disposed over the inner core center. The inner core center has a deflection of greater than 0.210 inch under a load of 100 kilograms, and the entire the core has a deflection ranging from 0.130 inch to 0.105 inch under a load of 100 kilograms. A mantle layer is disposed over the core and a cover is disposed over the mantle.

Abstract: An exemplary golf club head having an increased amount of discretionary mass may be realized by utilizing improved drop angles, an improved average crown height, and/or articulation points. The discretionary mass may be placed low and deep in the club head to improve the location of the center of gravity as well as the inertial properties. A preferred break length may also be utilized to further improve the depth of the center of gravity. In one example, the center of gravity may be positioned to substantially align the sweet spot with the face center of the club head.

Abstract: In a golf club, an apparatus which provides for a shaft to be adjustably secured to a head comprises a skewed axis shaft coupling and a shaft having an intermediate shaft section which joins a nominal shaft section to an offset shaft section such that they are offset one from the other. A shaft indexing mechanism provides for the nominal shaft section to have a plurality of indexed rotational positions in a socket of the skewed axis shaft coupling, thereby providing for the head to have, with respect to the offset shaft section, a plurality of possible sets of spatial and mass distribution properties. Furthermore, the skewed axis shaft coupling provides for the head to have, with respect to the nominal shaft section, a plurality of sets of angular properties.

Abstract: Embodiments of golf clubs, golf club heads, and methods of manufacture are described herein. In one embodiment, a golf club head includes a strike face having one or more grooves with edges, where one or more of the edges is unsmooth. Other embodiments are also described herein.

Abstract: A golf club head where at least a first portion of an exterior surface of the golf club head includes depressions is disclosed herein. More specifically, the golf club head has a body with a striking face, a crown portion, a sole portion, and a skirt portion joining the striking face, crown portion and the sole portion and in accordance with the present invention at least a portion of the exterior surface of the body of the golf club head is further comprised of depressions to reduce the aerodynamic drag force on the golf club head. The depressions may be provided on a first portion of the golf club head on one or more of a crown portion, sole portion, skirt portion or striking face.

Abstract: Multi-piece golf balls containing a dual-layered core and dual-layered cover are provided. The core structure includes a small, heavy inner core (center) having a relatively high specific gravity, and a surrounding outer core layer. The core layers may have different hardness gradients. The center of the core comprises a metal material such as copper, steel, brass, tungsten, titanium, aluminum, and combinations and alloys thereof preferably dispersed in a thermoplastic polymeric matrix. The outer core layer is preferably formed from a thermoset composition such as polybutadiene. The multi-layered cores and covers have selective specific gravity relationships between the different layers. This helps provide the ball with good flight distance and spin control. The resulting balls have good resiliency and other playing performance properties.

Abstract: An iron golf club head includes: a face portion including a ball striking surface and a first reverse surface; and a sole back portion including a second reverse surface connected with the first reverse surface and located below the first reverse surface. The iron golf club head has a first hollow separated from outside by the face portion and the sole back portion. The ratio W/V1 of the weight W (unit: g) of the iron golf club head relative to the volume V1 (unit: mm3) of the iron golf club head is 6.5×10?3 or less. The sole maximum projected width Sw of the iron golf club head is 25 mm or more. The sweet spot height Sh of the iron golf club head is 20 mm or more.

Abstract: A golf club head having a hollow structure includes a face, a crown, and a sole. The sole includes multiple elongated ribs. The ribs includes a first rib, a second rib, a third rib, and a fourth rib that are arranged in order from the toe side to the heel side. An end of the first rib and a first end of the second rib are connected to form a first connection end. A second end of the second rib and a first end of the third rib are connected to form a second connection end. A second end of the third rib and an end of the fourth rib are connected to form a third connection end. Each of the first rib and the fourth rib is longer than each of the second rib and the third rib.

Abstract: A golf training assembly has a plate structure configured for placement on a golf surface, such as a putting green. The training assembly has a mouth for receiving a rolling golf ball. The mouth guides the golf ball against a stop member for stopping and holding the golf ball in place allowing a golfer to practice putting.

Abstract: A golf club head includes a body having an outer surface with a recessed channel formed therein. A weight assembly that includes a weight at least partially disposed within the recessed channel, a cover extending over the recessed channel, and a fastener coupling the cover to the body. The fastener is adapted to retain the weight in the recessed channel only indirectly by the cover. The weight assembly is positionable in an unlocked configuration and a locked configuration. When the weight assembly is in the unlocked configuration, the cover is lifted out of the recessed channel and the weight is selectively slidable within the recessed channel. When the weight assembly is in the locked configuration, the cover is disposed within the recessed channel and the weight is secured within the recessed channel. The weight assembly is coupled to the body in both the unlocked configuration and the locked configuration.

Abstract: Provided is a method for manufacturing an iron golf club head by forging a single round rod member with a pair of dies to form, as a single piece, a body and a neck into which a shaft is to be inserted. The method includes: a first step of heating the single round rod member into a heated material; a second step of placing the heated material in the pair of dies; and a third step of forging the heated material placed in the pair of dies. In the third step, the heated material is prevented from flowing out from parting surfaces of the respective dies at a sole side of the body in the pair of dies, and the heated material blocked at the sole side in the pair of dies flows toward each of a toe of the body and the neck in the pair of dies.

Abstract: Hinges for multipurpose golf training aids, and more particularly, long-wearing, durable low-profile hinges for multipurpose golf training aids, and methods for manufacturing such hinges are disclosed.