A passive railroad crossing warning device has two input optical windows that receive light from the headlight of an oncoming locomotive. The light is redirected to an output optical window where a combiner causes it to exit at a predetermined angle to make it visible to motorists approaching the railroad crossing.
申请公布号
US5130848(A)
申请公布日期
1992.07.14
申请号
US19910660788
申请日期
1991.02.26
申请人
MINNESOTA MINING AND MANUFACTURING COMPANY
发明人
MILLER, RICHARD A.;THEIRL, SCOTT G.;AHO, KENNETH A.