Fluid pressure responsive transducer

Claim 2

A pressure-responsive current-modulating device operative over a wide range of pressures and including a displaceable member exposed to a source of variable pressure, multiple-rate spring means acting upon said member to oppose displacement thereof, and a variable impedance means operatively responsive to displacement of said member to vary the electrical circuit impedance presented by said device, said spring means comprising a Belleville spring and a coil spring.

Claim 3

A pressure-responsive device in accordance with claim 1 wherein said Belleville spring has a lower spring rate than said coiL spring.

Claim 4

A pressure sensing and indicating system including a fluid pressure responsive current-modulating device of claim 2 and connected in electrical circuit with a source of electrical power and a current-activated indicating device, said system exhibiting an enhanced sensitivity and indicating response over a low fluid pressure portion of the operating range of the system by reason of the mechanical characteristics of the spring means of the fluid pressure responsive device.

Claim 5

In a fluid pressure responsive current-modulating device operative over a wide range of fluid pressures and including a cup-shaped member, a flexible diaphragm cover for said member, means connected to said member and defining a chamber one wall whereof is constituted by said diaphragm, means defining a passage for admitting pressure fluid to said chamber, spring means acting between one end of said cup-shaped member and said diaphragm, a cuplike retainer for the end of said spring means bearing against said diaphragm, and a variable resistance means having a movable part operatively responsive to movement of said cuplike retainer as influenced by pressures acting against said diaphragm, the improvement wherein said spring means is possessed of different rates of opposition to displacement of said diaphragm over different portions of the operating range of the device and presents a lower rate of opposition to displacement of the diaphragm over a low fluid pressure portion of the operating range of the device than that presented by the spring means for a higher fluid pressure portion of said operating range, said spring means comprising a Belleville spring positioned adjacent the said one end of said cup-shaped member and a coil spring in force transmitting relation with and bearing at one end against the Belleville spring and at its other end against the diaphragm through said cuplike retainer.

Claim 6

In a fluid pressure responsive current-modulating device operative over a wide range of fluid pressures and including a cup-shaped member, a flexible diaphragm cover for said member, means connected to said member and defining a chamber one wall whereof is constituted by said diaphragm, means defining a passage for admitting pressure fluid to said chamber, spring means acting between one end of said cup-shaped member and said diaphragm, a cuplike retainer for the end of said spring means bearing against said diaphragm, and a variable resistance means having a movable part operatively responsive to movement of said cuplike retainer as influenced by pressures acting against said diaphragm, the improvement wherein said spring means is possessed of different rates of opposition to displacement of said diaphragm over different portions of the operating range of the device and presents a lower rate of opposition to displacement of the diaphragm over a low fluid pressure portion of the operating range of the device than that presented by the spring means for a higher fluid pressure portion of said operating range, said spring means comprising a Belleville spring positioned adjacent the said one end of said cup-shaped member and a coil spring in force transmitting relation with and bearing at one end against the Belleville spring and at its other end against the diaphragm through said cuplike retainer.

Claim 7

A fluid pressure responsive current-modulating device in accordance with claim 4 wherein said Belleville spring has a spring rate less than that of the coil spring.