Artificial horizon instrument for aircraft operation

Claim 1

AN ARTIFICIAL HORIZON INSTRUMENT FOR AIRCRAFT COMPRISING A CLOSED CYLINDRICAL HOUSING, A SEMICIRCLAR SLOT IN THE WALL OF SAID HOUSING INTERMEDIATE ITS ENDS, AN ELECTRIC LAMP POSITIONED IN SAID HOUSING ADJACENT ONE OF SAID ENDS, A CONICAL REFLECTOR AFFIXED IN SAID HOUSING IN ALIGNMENT WITH SAID ELECTRIC LAMP AND OPPOSITE SAID SEMICIRCULAR SLOT, OPTICAL FOCUSING MEANS POSITIONED IN SAID HOUSING BETWEEN SAID ELECTRIC LAMP AND SAID CONICAL REFLECTOR, A GIMBAL BRACKET ROTATABLY FIXED TO THE STRUCTURE OF SAID AIRCRAFT FOR ROTATION ABOUT A FIRST AXIS, SAID CLOSED HOUSING CARRIED BY SAID GIMBAL BRACKET FOR ROTATIONAL MOVEMENT ABOUT A SECOND AXIS PERPENDICULAR TO SAID FIRST AXIS, AND GYROSCOPIC MEANS CONTROLLING THE MOVEMENTS OF SAID GIMBAL BRACKET ABOUT SAID FIRST AXIS AND THE MOVEMENT OF SAID CLOSED HOUSING ABOUT SAID SECOND AXIS, SAID HOUSING POSITIONED REARWARDLY OF THE WINDSHIELD OF SAID AIRCRAFT WHEREBY A NARROW FLAT BEAM OF LIGHT FROM SAID SEMICIRCULAR SLOT IS PROJECTED TO THE WINDSHIELD OF SAID AIRCRAFT AND EXTENDS ACROSS THE WIDTH THEREOF.