Lubrication warning signal

Claim 1

IN A LUBRICATING SYSTEM FOR AN AUTOMOBILE ENGINE, A FILTER FOR LUBRICATING FLUID, A PUMP CONNECTED WITH THE UPSTREAM SIDE OF SAID FILTER FOR PUMPING PRESSURIZED LUBRICATING FLUID THERETHROUGH, A GALLERY CONNECTED WITH THE DOWNSTREAM SIDE OF SAID FILTER FOR DISTRIBUTING FILTERED LUBRICATING FLUID TO SAID ENGINE, A PAIR OF FLEXIBLE DIAPHRAGMS SPACED TO DEFINE A CHAMBER THEREBETWEEN, MEANS FOR CONDUCTING THE PRESSURE OF SAID GALLERY TO SAID CHAMBER FOR APPLYING SAID GALLERY PRESSURE TO SAID DIAPHRAGMS, MEANS FOR CONDUCTING THE DISCHARGE PRESSURE OF SAID PUMP AT A LOCATION UPSTREAM OF SAID FILTER TO ONE OF SAID DIAPHRAGMS EXTERIORLY OF SAID CHAMBER TO APPLY SAID DISCHARGE PRESSURE TO SAID ONE DIAPHRAGM IN OPPOSITION TO SAID GALLERY PRESSURE WITHIN SAID CHAMBER, SAID ONE DIAPHRAGM BEING THEREBY ACTUATED BY THE DIFFERENTIAL IN FLUID PRESSURES ACTING THEREON FROM WITHIN SAID CHAMBER AND EXTERIORLY THEREOF, FIRST AND SECOND RESILIENT BIASING SPRINGS ASSOCIATED WITH SAID ONE AND THE OTHER OF SAID DIAPHRAGMS RESPECTIVELY FOR BIASING SAID ONE DIAPHRAGM IN OPPOSITION TO SAID PUMP DISCHARGE PRESSURE AND FOR BIASING SAID OTHER DIAPHRAGM IN OPPOSITION TO SAID GALLERY PRESSURE, AN ELECTRICAL WARNING CIRCUIT INCLUDING FIRST AND SECOND SIGNAL ELEMENTS, FIRST ELECTRICAL CONTACT MEANS ASSOCIATED WITH SAID ONE DIAPHRAGM AND FIRST SIGNAL ELEMENT FOR ACTUATING THE LATTER WHEN SAID DIFFERENTIAL IN FLUID PRESSURE EXCEEDS A PREDETERMINED MAXIMUM VALUE DETERMINED BY SAID FIRST BIASING SPRING, AND SECOND ELECTRICAL CONTACT MEANS ASSOCIATED WITH THE OTHER OF SAID DIAPHRAGMS AND SECOND SIGNAL ELEMENT FOR ACTUATING THE LATTER WHEN THE FLUID PRESSURE WITHIN SAID CHAMBER FALLS BELOW A PREDETERMINED MINIMUM VALUE DETERMINED BY SAID SECOND BIASING SPRING.