Golf club having a damping element for ball speed control

1. A golf club head comprising:

a striking face;

a back portion behind said striking face extending from a topline to a sole;

a hosel configured to receive a shaft, said hosel located on a heel side of said golf club head, said heel side located opposite a toe side;

a coordinate system centered at a center of gravity of said golf club head, said coordinate system comprising a y-axis extending vertically, perpendicular to a ground plane when said golf club head is in an address position at a prescribed loft and lie, an x-axis perpendicular to said y-axis and parallel to said striking face, extending towards said heel side of said golf club head, and a z-axis, perpendicular to said y-axis and said x-axis and extending through said striking face;

a plurality of scorelines on said striking face;

a damping element comprising a front surface and a rear surface, said rear surface of said damping element opposite said front surface of said damping element;

wherein said striking face comprises a front surface configured to strike a golf ball and a rear surface opposite said front surface;

wherein said front surface of said damping element contacts said rear surface of said striking face;

wherein said striking face comprises a first portion having a constant thickness;

wherein said front surface of said damping element contacts said first portion of said striking face;

wherein said rear surface of said damping element contacts said back portion of said golf club head; and

wherein said front surface of said damping element has a hemispherical shape.

2. The golf club head of claim 1 , wherein said damping element has an elastic modulus of 40 GPa or greater.

3. The golf club head of claim 2 , wherein said damping element has an elastic modulus of 70 GPa or greater.

4. The golf club head of claim 3 , wherein said damping element is made from metal.

5. The golf club head of claim 4 , wherein said damping element is made from aluminum, steel, or titanium.

6. The golf club head of claim 2 , wherein said damping element further comprises an epoxy or a lubricant at said front surface of said damping element.

7. The golf club head of claim 2 , wherein said first portion of said striking face has a thickness greater than 1.5 mm and less than 2.5 mm.

8. A golf club head comprising:

a striking face;

a back portion behind said striking face extending from a topline to a sole;

a hosel configured to receive a shaft, said hosel located on a heel side of said golf club head, said heel side located opposite a toe side;

a coordinate system centered at a center of gravity of said golf club head, said coordinate system comprising a y-axis extending vertically, perpendicular to a ground plane when said golf club head is in an address position at a prescribed loft and lie, an x-axis perpendicular to said y-axis and parallel to said striking face, extending towards said heel side of said golf club head, and a z-axis, perpendicular to said y-axis and said x-axis and extending through said striking face;

a plurality of scorelines on said striking face;

a damping element comprising a front surface and a rear surface, said rear surface of said damping element opposite said front surface of said damping element;

wherein said striking face comprises a front surface configured to strike a golf ball and a rear surface opposite said front surface;

wherein said front surface of said damping element contacts said rear surface of said striking face;

wherein said striking face comprises a first portion having a constant thickness;

wherein said front surface of said damping element contacts said first portion of said striking face;

wherein said rear surface of said damping element contacts said back portion of said golf club head;

wherein said front surface of said damping element comprises a geometric center;

wherein said back portion of said golf club head comprises an adjustment mechanism configured to adjust a compression of said damping element against said striking face; and

wherein said front surface of said damping element has a hemispherical shape.

9. The golf club head of claim 8 , wherein said adjustment mechanism includes an adjustment driver and an adjustment receiver, wherein said adjustment receiver is configured to receive said adjustment driver by threaded engagement.

10. The golf club head of claim 9 , wherein said damping element has an elastic modulus of 40 GPa or greater.

11. The golf club head of claim 10 , wherein said damping element has an elastic modulus of 70 GPa or greater.

12. The golf club head of claim 11 , wherein said damping element is made from steel or titanium.

13. The golf club head of claim 12 , wherein said first portion of said striking face has a thickness greater than 1.5 mm and less than 2.5 mm.

14. The golf club head of claim 13 , wherein said damping element further comprises an epoxy or a lubricant at said front surface of said damping element.

15. The golf club head of claim 14 , wherein said striking face comprises a second portion, said second portion of said striking face having a thickness which tapers from a maximum thickness at a thick end of said second portion to a minimum thickness at a thin end of said second portion, wherein said thick end is located toeward of said thin end.

16. The golf club head of claim 15 , wherein said striking face comprises a third portion, said third portion of said striking face having a thickness which tapers from a maximum thickness at a heel end of said third portion to a minimum thickness at a toe end of said third portion.