Accelerometer

Claim 1

A LINEAR ACCELEROMETER COMPRISING: A HOLLOW SOFT IRON CONTAINER; A PERMANENT MAGNET; A PAIR OF POLE PIECES, SAID CONTAINER, SAID PERMANENT MAGNET, AND SAID POLE PIECES BEING CONNECTED TOGETHER SUCH THAT SAID POLE PIECES ARE POSITIONED CONTIGUOUSLY IN A SPACED RELATIONSHIP DEFINING AN ELONGATED GAP THEREBETWEEN, AND SAID PERMANENT MAGNET BEING EFFECTIVE TO CAUSE MAGNETIC FLUX TO FLOW BETWEEN SAID POLE PIECES SUCH THAT A SUBSTANTIALLY UNIFORM MAGNETIC FLUX FIELD IS SET UP IN SAID ELONGATED GAP; A RESISTANCE ELEMENT POSITIONED ADJACENT TO SAID ELONGATED GAP AND COOPERATING WITH SAID POLE PIECES TO FORM AN ELONGATED CHANNEL THEREBETWEEN; A CONDUCTOR ELEMENT POSITIONED ADJACENT TO SAID CHANNEL AND COOPERATING WITH SAID POLE PIECES AND SAID RESISTANCE ELEMENT TO FORM AN ELONGATED PASSAGE THEREBETWEEN; A LIQUID METAL SEISMIC MASS ELEMENT POSITIONED WITHIN SAID PASSAGE AND ADAPTED TO MOVE AXIALLY ALONG AND RELATIVE TO SAID ELEMENTS FORMING SAID PASSAGE IN RESPONSE TO ACCELERATIONS ALONG SAID PASSAGE, SAID SEISMIC MASS ELEMENT HAVING A NORMAL POSITION AT THE CENTER OF SAID PASSAGE, AND SAID POLE PIECES BEING ELECTRICALLY INSULATED FROM SAID MASS ELEMENT, SAID RESISTANCE ELEMENT, AND SAID CONDUCTOR ELEMENT; A GAS RETURN PORT CONNECTING THE ENDS OF SAID PASSAGE; AND A FILTER ELEMENT POSITIONED IN SAID GAS RETURN PORT ADJACENT TO EACH END OF SAID PASSAGE AND PREVENTING SAID MASS ELEMENT FROM ENTERING SAID GAS RETURN PORT; MEANS FOR CONNECTING SAID RESISTANCE ELETO A SOURCE OF ALTERNATING CURRENT, AND SAID RESISTANCE ELEMENT, SAID SEISMIC MASS ELEMENT, AND SAID CONDUCTOR ELEMENT BEING ELECTRICALLY CONNECTED AND DEFINING A CURRENT PATH.