FRANKFORT, Ky. (AP) — Kentucky’s governor has signed legislation aimed at securing the legality of betting on historical racing machines. Gov. Andy Beshear said Monday that the measure protects the state’s thoroughbred industry. But he says more work remains to enact “a more fair and equitable tax structure.” His comments reflect calls by some lawmakers for a higher tax rate on historical racing operations. The slots-style historical racing machines allow people to bet on randomly generated, past horse races. The venture has become a lucrative revenue source for the state’s racetracks.