| 摘要 |
<p>PURPOSE:To give a spin to a golf ball to correct the track of the golf ball shot deviatedly from the center by minimizing the thickness of the back of a ball shot surface at the center portion to increase the thickness toward both ends deviated from the center, or densifying the metal structure toward both ends and coarsening it toward the center, or varying both thickness and metal structure. CONSTITUTION:The thickness of a putter at the center back face of the ball shot surface is minimized, and thickened toward both ends. The cross section of the ball shot surface has a curved surface or taper-cut one. When the putter head is a casting, the metal structure is coarsened toward a gate and densified apart from the gate. Thus, the center portion of the putter head has a weak repulsion compared with that of the end to give a spin to the ball.</p> |
