MULTI-PIECE SOLID GOLF BALL

摘要

In a multi-piece solid golf ball having a core, an envelope layer, an intermediate layer and a cover, the surface hardnesses of the respective layers are set so as to satisfy specific relationships. Also, the initial velocities measured for the core, for a sphere obtained by forming the envelope layer over the core (envelope layer-encased sphere), for a sphere obtained by forming the envelope layer and the intermediate layer over the core (intermediate layer-encased sphere) and for the ball are set so as to satisfy specific relationships. In addition, the deflection (mm) of the ball when compressed under a given load and the deflection (mm) of the intermediate layer-encased sphere when compressed under a given load are set so as satisfy a specific relationship.

主权项

1. A multi-piece solid golf ball comprising a core, an envelope layer, an intermediate layer and a cover, wherein the core, envelope layer, intermediate layer and cover have respective surface hardnesses which satisfy the relationship:
core surface hardness>envelope layer surface hardness−40≦(envelope layer surface hardness−core surface hardness)≦−5; the surface hardness of the intermediate layer and the surface hardness of the cover, expressed in terms of Shore D hardness, satisfy the relationship:
5≦(cover surface hardness−intermediate layer surface hardness)≦15; the ball and a sphere composed of the core covered peripherally by the envelope layer and the intermediate layer (intermediate layer-encased sphere) have respective initial velocities (m/s) which satisfy the relationship:
−1.0 m/s≦(ball initial velocity−intermediate layer-encased sphere initial velocity)≦0 m/s; the intermediate layer-encased sphere and a sphere composed of the core covered peripherally by the envelope layer (envelope layer-encased sphere) have respective initial velocities (m/s) which satisfy the relationship:
−0.2 m/s≦(intermediate layer-encased sphere initial velocity−envelope layer-encased sphere initial velocity); and the ball satisfies the relationship:
0.86≦A/B≦0.98, where A is the deflection (mm) of the ball when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf) and B is the deflection (mm) of the intermediate layer-encased sphere when compressed under a final load of 1,275 N (130 kgf) from an initial load of 98 N (10 kgf).