| 摘要 |
<p>A magnetic ball (1) comprises a hollow sphere (2) of magnetic material and a resilient covering (3). A target substituting for a golf hole has two parts, a thin plate (4) of permeable magnetic material, and a cylindrical permanent magnetic (5) of significant thickness mounted upon the plate. The plate size is approximately equal to that of a golf hole. The magnet (5) physically obstructs the passage of a ball over the plate, the thickness of the magnet being chosen to give the desired degree of obstruction. The magnet is strong enough positively to locate a ball on the plate. The degree of physical obstruction reduces with increasing distance between the line of travel of the ball and the centre of the disc. In other embodiments physical obstruction to the passage of the ball is provided by a ring 6 or vanes 9.</p> |
