Florida prepares to execute killer of mother, two daughters*)Jackie H allifaxTHE ASSOCIATED PRESSThirteen hours before Davis was the first in a new electric chair.TALLAHASSEE — Seventeen vears after Allen Lee ‘Tiny” Davis broke into a Jacksonville home, bludgeoned a woman and shot her two young daughters, the condemned killer waited in vain Wednesday for a stay of execution.scheduled to go to Florida’s electricchair at 7 a.m. today, the U.S.Supreme Court rejected two petitions asking for delays. No other appeals were pending.Florida has not had an execution for 15 months. If carried out, Davis' execution will be the first under a warrant signed by Gov. Jeb Bush and expires.The nation’s high court refused Tuesday night to stop the execution of Thomas Provenzano, originally set for Wednesday morning. A short time later the Florida Supreme Court granted Provenzano a two-day delay. His execution was set for 7:01 a.m. Friday, a minute after the stayProvenzano, condemned for the 1984 shooting of an Orlando bailiff, won his stay with a claim of insanity. But his allegation that the electric chair wouldn’t work properly was rejected by both the U.S. Supreme Court and the Florida Supreme Court.Davis isn’t claiming insanity. Both appeals he had before the U.S. Supreme Court Wednesday werebased on allegations that the electric chair won’t work properly — especially with a man the size of Davis.Davis, 54, stands 6-foot-2 and weighs about 350 pounds.His lawyers aren’t concerned about the chair itself but the related electrical equipment.The state replaced the oaken chair.See EXECUTION page 6A