Planar ring and blister diaphragm for improved diaphragm-type pressure sensor

Abstract

A Pressure Sensing Apparatus is disclosed. Also disclosed is a diaphragm-type pressure sensor comprising a planar ring with a blister formed on said planar ring. The planar ring diaphragm-type pressure sensor is designed to function as an integral part of the overall larger pressure sensing apparatus, although it also has other uses. The planar ring diaphragm type pressure sensor may have a blister which is either larger or smaller than the width of the planar ring depending on the intended use. Furthermore, the blister on the planar ring may be light reflective.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional application of application Ser. No. 10 / 638,586, filed Aug. 11, 2003, which is a continuation-in-part of application Ser. No. 09 / 357,056, filed Jul. 19, 1999 and issued as U.S. Pat. No. 6,604,427 on Aug. 12, 2003.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] This invention relates generally to pressure sensors and, more specifically, to a Pressure Sensing Apparatus. [0004] 2. Description of Related Art [0005] The bellows-type pressure sensor is widely used in high sensitivity applications. Essentially, what is involved is a very small bellow that is configured to reflect light onto a detector. When the bellow stretches or contracts in response to a pressure change, the detector will sense a corresponding change in the light intensity. [0006]FIG. 1 is a perspective view of a prior art bellow assembly 10. As can be seen, from its outer dimensions, the bellow assembly 10 comprises a ste...

AI Technical Summary

Benefits of technology

[0013] In light of the aforementioned problems associated with the prior devices, it is an object of the present invention to provide a Pressure Sensing Apparatus. It is an object that the improved apparatus provide increased pressure sensitivity without added cost and complexity in the electronic detector circuitry. It is a further object that the apparatus be less sensitive to gravity, vibrations or other external influences. It is a still further object that the apparatus be available with either concave or convex reflective surfaces, or a lens. It is a further object that the signal strength be increased. Other versions of the apparatus should have a deflectable focusing diaphragm that permits pressure detection responsive to the curvature of the diaphragm in response to pressure differentials across the diaphragm.

Problems solved by technology

In fact, in order to sense this changed distance, detector 20 must be extremely sensitive (and therefore expensive).

As such, where the sensor is experiencing vibrations they might actually be sensed as pressure changes but in fact this is not necessarily the case.

This, again, adds expense because the detector must be isolated for many external acceleration-type forces.

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