# US 9,039,545 B2 · Multi-piece solid golf ball > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,039,545 B2 - Document ID: US9039545B2 - Status: Granted - Kind: B2 - Application number: 12/910,395 - Filed: 2010-10-22 - Published: 2012-04-26 - Granted: 2015-05-26 - Earliest claimed: 2010-10-22 - Assignees: Bridgestone Sports Co., Ltd. - Applicants: Hideo Watanabe; Junji Umezawa - Inventors: Hideo Watanabe; Junji Umezawa - Web page: https://patentgrep.com/patent/US9039545B2 ## CPC - A63B 37/0031: {Hardness} - A63B 37/0033: {Thickness} - A63B 37/0043: {Hardness} - A63B 37/0045: {Thickness} - A63B 37/00621: {Centre hardness} - A63B 37/00622: {Surface hardness} - A63B 37/0065: {Deflection or compression} - A63B 37/0076: {Multi-piece balls, i.e. having two or more intermediate layers} - A63B 37/00922: {whereby hardness of the cover is lower than hardness of the intermediate layers} - A63B: APPARATUS FOR PHYSICAL TRAINING, GYMNASTICS, SWIMMING, CLIMBING, OR FENCING; BALL GAMES; TRAINING EQUIPMENT (apparatus for passive exercising, massage A61H) ## Abstract A multi-piece solid golf ball having a core, an envelope layer having an inner envelope layer, intermediate envelope layer and outer envelope layer, an intermediate layer, and a cover having a plurality of dimples formed on a surface thereof, arranged in that order. The three envelope layers, intermediate layer and cover are each formed primarily of a resin material of the same or different types. The core is formed primarily of a rubber material, and has a material hardness higher than the core center hardness. One of the inner layers has a material hardness higher than either or both of the cover material hardness and the average core hardness. The golf ball lowers the spin rate on full shots with a driver, increases the distance traveled by the ball, has good controllability, maintains a straight path particularly on full shots, has a good feel on impact and excellent scuff resistance. ## Claims ### Claim 1 A multi-piece solid golf ball comprising a core, an envelope layer encasing the core, an intermediate layer encasing the envelope layer, and a cover which encases the intermediate layer and has formed on a surface thereof a plurality of dimples, wherein the envelope layer consists of an inner envelope layer, an intermediate envelope layer and an outer envelope layer, such that the total number of layers in the multi-piece solid golf ball is six; the inner, intermediate and outer envelope layers, the intermediate layer and the cover are each formed primarily of a resin material which may be of the same or different types; the core is formed primarily of a rubber material; the cover has a material hardness (Shore D) which is higher than a core center hardness (Shore D); and one of the inner layers has a material hardness (Shore D) which is higher than either or both of the cover material hardness (Shore D) and the average core hardness (defined as the arithmetic mean of the core surface hardness and the core center hardness), wherein the intermediate envelope layer is formed so as to be harder than the inner envelope layer and to have a material hardness difference (Shore D) with the inner envelope layer of from 1 to 4, and so as to be softer than the outer envelope layer and to have a material hardness difference (Shore D) with the outer envelope layer of from 1 to 4, wherein the inner envelope layer, intermediate envelope layer and outer envelope layer have thicknesses which satisfy the following relationship: inner envelope layer thickness>intermediate envelope thickness>outer envelope layer thickness, and wherein the ratios (intermediate envelope layer thickness)/(outer envelope layer thickness) and (inner envelope layer thickness)/(intermediate envelope layer thickness) are each at least 1.1. ### Claim 2 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the intermediate layer and the cover have thicknesses which satisfy the following relationship: 1.3≦intermediate layer thickness/cover thickness≦4.0. ### Claim 3 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the intermediate layer is formed of a material which includes an ionomer resin having an acid content of at least 16 wt %. ### Claim 4 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the core center, outer envelope layer, intermediate layer and cover have hardnesses (Shore D) which satisfy the following relationship: cover material hardnessouter envelope layer material hardness>core center hardness. ### Claim 5 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the core center, inner envelope layer, intermediate envelope layer, outer envelope layer, intermediate layer and cover have hardnesses (Shore D) which satisfy the following relationship: cover material hardnessouter envelope layer material hardness>intermediate envelope layer material hardness>inner envelope layer material hardness>core center hardness. ### Claim 6 (depends on 1) The multi-piece solid golf ball of claim 1, wherein the core, inner envelope layer, intermediate envelope layer, outer envelope layer, intermediate layer and cover have thicknesses which satisfy the following relationship: cover thickness