Pressure gradient transducer

Claim 2

A pressure gradient electroacoustic transducer comprising a transducer element assembly having a pair of parallel surfaces, separate vibratile diaphragm means coupled to each of said parallel surfaces, means responsive to an application of substantially equal alternating mechanical forces upon said diaphragms and saiD parallel surfaces for causing said transducer element to generate two separate and substantially equal alternating voltages, and means for connecting said transducer elements for applying said separate and substantially equal alternating voltages in subtractive relationship one to the other, whereby an application of substantially equal mechanical forces upon said diaphragms produces a zero output.

Claim 3

A pressure gradient electroacoustic transducer comprising a transducer element assembly having a pair of parallel surfaces, separate vibratile diaphragm means coupled to each of said parallel surfaces, means responsive to an application of substantially equal alternating mechanical forces upon said diaphragms and saiD parallel surfaces for causing said transducer element to generate two separate and substantially equal alternating voltages, and means for connecting said transducer elements for applying said separate and substantially equal alternating voltages in subtractive relationship one to the other, whereby an application of substantially equal mechanical forces upon said diaphragms produces a zero output.

Claim 4

A pressure gradient electroacoustic transducer comprising a transducer element assembly having a pair of parallel surfaces, separate vibratile diaphragm means coupled to each of said parallel surfaces, means responsive to an application of substantially equal alternating mechanical forces upon said diaphragms and saiD parallel surfaces for causing said transducer element to generate two separate and substantially equal alternating voltages, and means for connecting said transducer elements for applying said separate and substantially equal alternating voltages in subtractive relationship one to the other, whereby an application of substantially equal mechanical forces upon said diaphragms produces a zero output.

Claim 5

The invention of claim 1 wherein said electroacoustic transducer includes a tubular housing with an opening at each end of said tubular housing, said transducer element assembly being positioned centrally within said tubular housing, and said separate vibratile diaphragm means being attached to seal the open ends of said tubular housing.

Claim 6

An electroacoustic transducer comprising a tubular housing with an opening at each end of said tubular housing, a transducer element assembly having a pair of parallel surfaces, said transducer element assembly being positioned centrally within said tubular housing, separate vibratile diaphragm means coupled to each of said parallel surfaces, said separate vibratile diaphragm means being attached to seal the open ends of said tubular housing, said transducer element assembly includes a tubular piezoelectric element having electrode surfaces on both the inside and outside peripheral walls of said tubular piezoelectric element, means responsive to an application of substantially equal alternating mechanical forces upon said diaphragms and said parallel surfaces for causing said transducer element to generate two separate and substantially equal alternating voltages, means for applying said separate and substantially equal alternating voltages in subtractive relationship one to the other, whereby an application of substantially equal mechanical forces upon said diaphragms produces a zero output.

Claim 7

An electroacoustic transducer comprising a tubular housing with an opening at each end of said tubular housing, a transducer element assembly having a pair of parallel surfaces, said transducer element assembly being positioned centrally within said tubular housing, separate vibratile diaphragm means coupled to each of said parallel surfaces, said separate vibratile diaphragm means being attached to seal the open ends of said tubular housing, said transducer element assembly includes a tubular piezoelectric element having electrode surfaces on both the inside and outside peripheral walls of said tubular piezoelectric element, means responsive to an application of substantially equal alternating mechanical forces upon said diaphragms and said parallel surfaces for causing said transducer element to generate two separate and substantially equal alternating voltages, means for applying said separate and substantially equal alternating voltages in subtractive relationship one to the other, whereby an application of substantially equal mechanical forces upon said diaphragms produces a zero output.

Claim 8

The invention of claim 3 wherein at least one of said electrode surfaces on one of said peripheral walls of said tubular element is divided into two substantially equal and electrically separated areas.

Claim 9

The invention of claim 4 further characterized in that said voltage applying means is arranged to apply the voltages generated in each of said electrically separated areas in a subtractive relationship of one with respect to the other.

Claim 10

The invention of claim 3 further characterized in that the electrode surface on one peripheral wall of said tubular piezoelectric element is divided into two electrically separated areas of substantially equal size and still further characterized in that the electrode surface on the opposite peripheral wall is divided into four separated areas of substantially equal size.

Claim 11

The invention of claim 6 further characterized in that the wall of said tubular piezoelectric element is polarized in the same direction throughout the entire length of the tube.

Claim 12

The invention of claim 7 further characterized in that four separate voltages are generated between the two separated electrodes on one peripheral wall and the four electrodes on the opposite peripheral wall of the piezoelectric tube, and means for combining the four voltages so that each is subtractive one from the other.

Claim 13

The invention of claim 1 further characterized in that said transducer element assembly includes two similar piezoelectric plates, said plates each having two plane parallel surfaces, said piezoelectric plates being polarized so that opposite polarities appear at opposite surfaces, electrodes on each of said plane parallel surfaces, rigid bonding means between one of said electroded surfaces of said first plate and one of said electroded surfaces of said second plate, and separate vibratile diaphragm means rigidly connected to each of the other electroded surfaces of said rigidly bonded plates.

Claim 14

The invention of claim 9 further characterized in that said two piezoelectric plates are mechanically bonded together with electrodes of opposite polarity facing each other and still further characterized in that one electrical connection is made to said common facing electrodes and a second electrical connection is made in common to said opposite facing electrodes.