Pressure-sensing transducer

Claim 1

A pressure-sensing transducer which can be used to continuously measure the cylinder pressure in an internal combustion engine, said pressure-sensing transducer comprising a pressure-transmitting element which includes a generally tubular seat having a bottom end and a top end and defining a longitudinal axis therethrough, and a metallic plate which closes off the top end of said seat so as to form a cavity within said seat into which hot gases from an internal combustion engine can flow, said metallic plate including a centrally located projection portion extending away from its side opposite the cavity in said seat, a generally M-shaped force transmitting member having two outer legs and two inner legs, the bottom ends of the two inner legs being connected together and the top ends of the two inner legs being respectively connected to the top ends of the two outer legs, the bottom ends of the two outer legs being connected to opposite portions of the top end of said seat and the bottom ends of the two inner legs being connected to the projection portion of said metallic plate, and a force-sensing member connected between the top ends of the two outer legs of said generally M-shaped force-transmitting member so as to be oriented generally perpendicularly with respect to said longitudinal axis, said force-sensing member comprising a plate having four apertures therein, two of the apertures supporting an excitation winding and two of the apertures supporting a measuring winding, such that pressure forces acting along said longitudinal axis on said metallic plate from within said cavity will be transmitted by said force-transmitting member so as to create tensile forces in said force-sensing member measurable by said measuring winding.