Patent Publication Number: US 6238305 B1
Title: Wound golf ball
Filing Date: October 1, 1998
Priority Date: October 1, 1997
Inventor(s): Junji Umezawa, Shinichi Kakiuchi
Original Assignee / Applicant(s): Bridgestone Sports Co., Ltd.
Link to Patent: US6238305B1
Summary:
This invention claims a wound golf ball comprising a wound core consisting of a solid center and a thread rubber layer thereon, and a cover surrounding the wound core. The golf ball of this invention is claimed to present a contact area of 3.5-4.1 cm2 with the club face of No. 9 iron driven at a head speed of 35 m/s. This specification is said to improve the control, hitting feel and durability of the ball. The publication also discloses a method to determine the contact area, which involves applying Fujifilm Prescale® to the club face, and hitting a ball with the club. The region of the sheet that has contacted the ball changes its color, for example, to red. The area delimited by the boundary of the color changed region is determined.