A ball striking device, such as a golf club head, has a face with a striking surface configured for striking a ball; an elongated channel extending across a portion of the sole, wherein the sole has an elongated channel recessed from adjacent surfaces of the sole that has a plurality of troughs within the channel to help improve the efficiency of the impact with a golf ball.

Embodiments of putter-type golf club head comprising a striking surface capable of achieving consistent ball speeds across the striking surface to account for various ball impact locations are described herein. The striking surface has at least two materials that differ in concentration away from the geometric center of the striking surface to provide this consistency. Consistent (or uniform) ball speed is achieved throughout the striking surface as the portion of the golf ball that contacts the striking surface interacts with at least two materials having a differing material characteristic.

In an aspect, a sports ball includes a core including a negative Poisson's ratio (NPR) foam material, in which the core has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR polymer foam; and a cover layer surrounding the core. In an aspect, a golf club includes an elongated shaft; a grip disposed at a first end of the elongated shaft; and a head connected to a second end of the elongated shaft, the head having a flat face configured for contact with a golf ball, in which the flat face is formed of a negative Poisson's ratio (NPR) foam material, in which the head has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.

Examples of golf club heads and methods to manufacture golf club heads are generally described herein. In one example, a body portion of a golf club head may include a front portion. A face portion may be coupled to the front portion. The face portion may include a central strike portion and a perimeter. A plurality of projections may extend from the face portion to provide a ball striking surface for impacting a golf ball. The plurality of projections may be aligned in one or more directions across the face portion and may increase in size in one or more directions from the central strike portion to the perimeter of the face portion. Other examples and examples may be described and claimed.

Golf club heads include at least one weight port situated to retain weights and positioned above an approximate club face geometric center with the club in a standard address position. One, two, or more weight ports can be located above the club face center in a club crown or other portion of a club body. Club head vertical center of gravity can be selected to compensate dynamic loft associated with locating the club head center of gravity well behind the club face. Three-dimensional adjustment of club head center of gravity is possible.

A golf club head with a crown comprising an inner crown portion and an outer crown portion. The inner crown portion may be made of a low density or low elastic modulus material. The outer portion of the crown defines an opening to the cavity, a riser extending into the cavity, and a ledge extending from the edge of the riser. The ledge may define a first channel and a second channel that extend around the ledge. The first channel is filled with adhesive to secure the inner portion of the crown to the ledge. The inner portion of the crown is attached to the ledge such that the opening is covered by the inner portion of the crown. The golf club head may also have a sole comprising an inner sole portion and an outer sole portion.

Embodiments of a co-molded putter-type golf club head comprising a high-density chassis made of a first material and a low-density putter-type body made of a second material. The first material can be a high density metal (i.e., steel or tungsten, but not limited to). The second material can be a low density thermoplastic composite (i.e., polyphenylene sulfide (PPS), polyamide (PA), but not limited to). The chassis comprises a flow aperture, and one or more interlocking features. The putter-type body portion encases the entirety of the at least one interlocking feature. Further, the putter-type body encapsulates the chassis such that the body extends through, and completely fills the flow aperture, to interlock the body and chassis, and thus form the club head. Other embodiments may be described and claimed.

A golf club with a multi-material face is disclosed herein. More specifically, the golf club head in accordance with the present invention has a multi-material striking face portion that is made out of a backing layer having a frontal pocket, made out of titanium, and an insert, made out of a composite material, adapted to be inserted into the frontal pocket. The frontal pocket and the insert could have complementary dovetail shaped undercut features to create a mechanical bond between these two components.

A golf club with a multi-material face is disclosed herein. More specifically, the golf club head in accordance with the present invention has a multi-material striking face portion that is made out of a backing layer having a frontal pocket, made out of titanium, and an insert, made out of a composite material, adapted to be inserted into the frontal pocket. The frontal pocket and the insert could have complementary dovetail shaped undercut features to create a mechanical bond between these two components.

A golf club head that is capable improving on the inertia properties of a golf club head all while also improving the Center of Gravity (CG) location is disclosed herein. More specifically, the golf club head in accordance with the present invention achieves a relative low Moment of Inertia (MOI) about the Z-axis (MOI-Z) as well as a relatively low MOI about the Shaft-axis (MOI-SA), all combined with a high MOI about the X and Y-axis (MOI-X and MOI-Y) and maintaining a consistently and relatively low CG location measured along a direction tangent to the hosel axis along the X-Y plane (CG-B). The golf club head includes a frontal portion and a rear portion, each including one or more cantilevered extensions and one or more elongate protrusions that collectively constitute a snap fit mechanism adapted to removably couple the frontal portion to the rear portion.