Visual-audible alarm for a vacuum cleaner

Claim 1

IN COMBINATION, A SUCTION CLEANER HAVING A CASING WITH AN AIR INLET AND AN AIR OUTLET, A FILTER IN SAID CASING INTERPOSED BETWEEN SAID INLET AND SAID OUTLET, SUCTION MEANS IN SAID CASING FOR CAUSING AIR FLOW FROM SAID INLET THROUGH SAID FILTER TO SAID OUTLET, AND A COMBINED VISUALAUDIBLE SIGNAL DEVICE FOR INDICATING CLOGGING OF SAID FILTER, SAID SIGNAL DEVICE COMPRISING A HOUSING, A PRESSURE RESPONSIVE MEMBER MOVABLE IN SAID HOUSING IN RESPONSE TO A DIFFERENTIAL PRESSURE BETWEEN THE INSIDE AND OUTSIDE OF SAID CASING, SAID HOUSING HAVING AIR PASSAGE MEANS COMMUNICATING BETWEEN THE INSIDE AND OUTSIDE OF SAID CASING, AND EFFECTIVE TO EXPOSE OPPOSITE PORTIONS OF SAID MEMBER TO THE PRESSURES AT THE INSIDE AND OUTSIDE OF SAID CASING, MEANS PROVIDING A VISIBLE SIGNAL IN RESPONSE TO MOVEMENT OF SAID MEMBER UPON PARTIAL CLOGGING OF SAID FILTER, MEANS OPERATIVE IN RESPONSE TO MOVEMENT OF SAID MEMBER BEYOND A PREDETERMINED POSITION UPON FURTHER CLOGGING OF SAID FILTER FOR INCREASING THE FLOW OF AIR FROM OUTSIDE SAID CASING THROUGH SAID HOUSING TO THE INSIDE OF SAID CASING, AND MEANS PROVIDING AN AUDIBLE SIGNAL IN RESPONSE TO THE INCREASED AIR FLOW.