Document Type and Number:
Japanese Patent JP3921553
PROBLEM TO BE SOLVED: To provide a novel rotation indicator for athletes checking whether or not the rotation is rightly performed and constantly grasping the rotation in a single operation without depending on the memory of a person such as a judge in a ball game wherein the rotation of athletes is performed.
SOLUTION: This apparatus which grasps, when the right of service to serve a ball B is changed, respective positions of players in a ball game changing the respective positions is provided with a service right change operating part operated when the service right is changed, and rotating display boards 3R and 3L displaying by changing the rotation of respective players' positions determined by the operation of the service right change operation part 4.
March 02, 2007
November 19, 2003
A63B71/06; A63B71/06; (IPC1-7): A63B71/06