Abstract: Various forms of golf clubs are disclosed, which include one or more inflatable bladders in the golf club head and/or golf club shaft, as well as internal and external grooving of the golf club shaft. Such golf clubs have enhanced characteristics for driving a golf ball to move in a desired trajectory. The unique structural components of the golf club provide for reinforcing, rigidifying, reducing weight and more effective control of the golf club during the swing. A higher club head speed when impacting a golf ball, more stability on off center hits, reduced vibration upon ball impact, improved sound characteristics, and improved "feel" can be achieved.

Abstract: A metal wood type golf club head has a substantially hollow metallic body defining a bottom sole extending between a toe and heel, a top wall or crown, a ball striking face having parallel horizontal grooves, and a hosel formed at the heel to receive a shaft. The interior of the hollow body is filled with a foam material. The weight of the metallic body is distributed to establish an optimum impact point or sweet spot at substantially the geometric center of the ball striking face, and further establishes a plurality of substantially elliptical force lines on the face concentric with the sweet spot. Each elliptical force line represents a locus of points operative to impart substantially equal impact forces to a ball struck at a point on the corresponding elliptical force line, the major axis of the concentric elliptical force lines passing generally through the sweet spot substantially parallel to the grooves.

Abstract: Golf club irons of the perimeter weighted type are provided wherein each iron of a set includes a club head having a toe portion, a heel portion having a hosel, a ball-striking face having a plurality of parallel substantially horizontal grooves formed therein, and a generally convex back surface. A cavity is formed in the back surface of each club head and configured to selectively distribute the weight about the perimeter of the head to create a plurality of elliptical force lines concentric with the sweet spot on the club face and having their major axis substantially parallel to the grooves on the club face. Golf irons in accordance with the present invention effectively provide larger sweet spots on the hitting faces of the irons so as to produce results from off-center shots that more closely approach the results produced when balls are struck by the exact sweet spot on the club face.

Abstract: Golf club irons of the perimeter weighted type are provided wherein each iron of a set includes a club head having a toe portion, a heel portion having a hosel, a ball-striking face having a plurality of parallel substantially horizontal grooves formed therein, and a generally convex back surface. A cavity is formed in the back surface of each club head and configured to selectively distribute the weight about the perimeter of the head no create a plurality of elliptical force lines concentric with the sweet spot on the club face and having their major axis substantially parallel to the grooves on the club face. Golf irons in accordance with the present invention effectively provide larger sweet spots on the hitting faces of the irons so as to produce results from off-center shots that more closely approach the results produced when balls are struck by the exact sweet spot on the club face.