Load measuring system

Claim 1

IN COMBINATION, MEANS DEFINING A CHAMBER, A WAVE PROPAGATION MEDIUM FILLING SAID CHAMBER, AN ELECTROACOUSTIC TRANSDUCER IN SAID CHAMBER, MEANS PROVIDING A WAVE REFLECTING SURFACE IN SAID CHAMBER OPPOSITE SAID TRANSDUCER, SAID SURFACE AND SAID TRANSDUCER BEING MOVABLE RELATIVE TO EACH OTHER TO VARY THE DISTANCE THEREBETWEEN, LOAD RECEIVING MEANS, SAID LOAD RECEIVING MEANS BEING ADAPTED TO PRODUCE RELATIVE MOVEMENT OF SAID SURFACE AND SAID TRANSDUCER TOWARD EACH OTHER UPON APPLICATION OF LOAD THERETO A DISTANCE PROPORTIONAL TO THE MAGNITUDE OF THE LOAD APPLIED THERETO, MEANS FOR ELECTRICALLY EXCITING SAID TRANSDUCER TO TRANSMIT AN ACOUSTIC WAVE TOWARD SAID SURFACE, WHEREBY THE WAVE IS REFLECTED FROM SAID SURFACE TOWARD SAID TRANSDUCER, MEANS FOR DETECTING WHEN THE REFLECTED WAVE STRIKES THE TRANSDUCER AND ELECTRICALLY EXCITES SAID TRANSDUCER IN RESPONSE THERETO, AND MEANS FOR MEASURING THE TIME REQUIRED FOR A PREDETERMINED NUMBER OF WAVES TO BE REFLECTED FROM SAID SURFACE TO SAID TRANSDUCER.