Structure for protecting a suction cleaner motor from overheating

Claim 1

A SUCTION CLEANER COMPRISING A CASING, SAID CASING HAVING FIRST AND SECOND INLETS FOR AIR AND AN OUTLET FOR AIR, SAID CASING FROM A ZONE INTERMEDIATE SAID OUTLET AND SAID FIRST AND SECOND INLETS HAVING FIRST AND SECOND PASSAGEWAYS EXTENDING THEREFROM WHICH RESPECTIVELY COMMUNICATE WITH SAID FIRST AND SECOND INLETS AND A COMMON PASSAGEWAY EXTENDING FROM SAID ZONE WHICH COMMUNICATES WITH SAID FIRST AND SECOND PASSAGEWAYS AND SAID OUTLET, MEANS IN SAID COMMON PASSAGEWAY FOR FLOWING AIR THROUGH SAID FIRST AND SECOND PASSAGEWAYS AND THENCE THROUGH SAID COMMON PASSAGEWAY FROM SAID FIRST AND SECOND INLETS TO SAID OUTLET, AN AIR PERMEABLE DIRT COLLECTOR IN SAID FIRST PASSAGEWAY FOR COLLECTING DIRT FROM AIR WHICH PASSED THERETHROUGH, VALVE MEANS MOVABLE BETWEEN OPEN AND CLOSED POSITIONS FOR CONTROLLING FLOW OF AIR THROUGH SAID SECOND PASSAGEWAY, MEANS FOR NORMALLY BIASING SAID VALVE MEANS TO ITS CLOSED POSITION, SAID AIR MOVING MEANS INCLUDING AN ELECTRIC MOTOR AND A FAN DRIVEN THEREBY, MEANS INCLUDING A MANUALLY OPERABLE SWITCH MOVABLY BETWEEN CLOSED AND OPEN POSITIONS FOR RESPECTIVELY CONNECTING AND DISCONNECTING SAID MOTOR TO AND FROM A SOURCE OF ELECTRICAL ENERGY, SAID FAN BEING CONNECTED TO RECEIVE AIR FROM SAID FIRST AND SECOND PASSAGEWAYS, MEANS TO FLOW ALL OF THE AIR DISCHARGED FROM SAID FAN THROUGH SAID MOTOR TO EFFECT COOLING THEREOF, MECHANISM FOR MOVING SAID VALVE MEANS FROM ITS CLOSED POSITION TO ITS OPEN POSITION AGAINST THE ACTION OF SAID BIASING MEANS, SAID MECHANISM NORMALLY BEING INOPERABLE TO MOVE SAID VALVE MEANS FROM ITS CLOSED POSITION TO ITS OPEN POSITION WHEN SAID MOTOR OPERATES IN A NORMAL TEMPERATURE RANGE AND SAID AIR PERMEABLE DIRT COLLECTOR NORMALLY FUNCTIONS TO ALLOW AIR TO FLOW THERETHROUGH DURING OPERATION OF THE CLEANER, SAID MOTOR TENDING TO OPERATE AT AN ABNORMALLY HIGH TEMPERATURE ABOVE SAID NORMAL TEMPERATURE RANGE WHEN SUFFICIENT DIRT COLLECTS IN SAID AIR PERMEABLE DIRT COLLECTOR TO OBSTRUCT FLOW OF AIR THERETHROUGH, WHEREBY NORMAL COOLING OF SAID MOTOR IS IMPAIRED, AND MEANS RESPONSIVE TO A TEMPERATURE CONDITION AFFECTED BY SAID MOTOR WHEN THE LATTER OPERATES AT SAID ABNORMALLY HIGH TEMPERATURE TO RENDER SAID MECHANISM OPERABLE TO MOVE SAID VALVE MEANS FROM ITS CLOSED POSITION ITS OPEN POSITION AGAINST THE ACTION OF SAID BIASING MEANS WHILE SAID SWITCH IS IN ITS CLOSED POSITION AND SAID MOTOR IS CONNECTED TO THE SOURCE OF ELECTRICAL ENERGY, SAID VALVE MEANS IN ITS OPEN POSITION FUNCTIONING TO ALLOW AIR TO FLOW SUCCESSIVELY THROUGH SAID SECOND PASSAGEWAY AND SAID COMMON PASSAGEWAY TO PROMOTE COOLING OF SAID MOTOR BY AIR FLOWING THERETHOUGH, WHEREBY SAID MOTOR WILL OPERATE AGAIN IN SAID NORMAL TEMPERATURE RANGE.