Illuminator cooling system

Claim 1

IN AN ILLUMINATOR FOR MICROSCOPES, A HOUSING INCLUDING FRONT, REAR, TOP BOTTOM AND SIDE WALLS, DEFINING AN ENCLOSURE WITH SAID REAR WALL HAVING UPPER AND LOWER OPENINGS, A CONDENSER LENS ASSEMBLY EXTENDING THROUGH SAID FRONT WALL AND SLIDABLY RECEIVED THEREIN, A LIGHT CHAMBER ENVELOPE MOUNTED WITHIN SAID HOUSING IN REARWARDLY SPACED RELATION TO SAID FRONT WALL AND HAVING AN OPENING THEREIN RECEIVING THE REARWARD EXTREMITY OF SAID CONDENSER LENS ASSEMBLY, A LIGHT SOURCE MOUNTED IN SAID ENVELOPE FOR PROJECTING LIGHT THROUGH SAID CONDENSER LENS ASSEMBLY, SAID ENVELOPE EXTENDING FROM CLOSELY ADJACENT ONE OF SAID SIDE WALLS TO CLOSELY ADJACENT THE OPPOSITE SIDE WALL OF THE HOUSING AND BEING SPACED FROM BOTH THE TOP AND BOTTOM WALLS THEREOF, FAN MEANS MOUNTED IN SAID ENCLOSURE REARWARDLY OF SAID ENVELOPE AND POSITIONED TO DIRECT AIR THROUGH SAID LOWER OPENING IN THE REAR WALL OF THE HOUSING AGAINST THE LOWER REGION OF SAID ENVELOPE AND TOWARD SAID FRONT WALL OF THE HOUSING WHEREBY TO CHANNEL INCOMING AIR BELOW SAID ENVELOPE, UPWARDLY ACROSS THE FRONT THEREOF, AND REARWARDLY OVER THE TOP THEREOF TOWARD SAID UPPER OPENING IN SAID REAR WALL OF THE HOUSING, SAID ENVELOPE HAVING OPENINGS IN THE UPPER AND LOWER REGIONS THEREOF TO PERMIT RESTRICTED AIR FLOW UPWARDLY THERETHROUGH, SAID ENVELOPE HAVING A FRONT WALL EXTENSION OVERLYING THE OPENING IN THE UPPER REGION OF THE ENVELOPE AND SPACED BELOW THE TOP WALL OF THE HOUSING.