ACCELERATION STRAIN TRANSDUCER

• US 20090114031A1
• Filed: 11/05/2007
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: Government of the United States of America
• Original Assignee: Government of the United States of America
• Inventors: Maguire, Jason M., Ames, Gregory H.
• Granted Patent: US 7,661,313 B2
• Time in Patent Office: Days
• US Class Current: 73/760
• CPC Class Codes: G01P 15/08 with conversion into electric or magnetic values
• CPC Class Codes: G01P 15/0802 Details
• CPC Class Codes: G01P 15/093 by photoelectric pick-up

Abstract

An accelerometer is provided including a strain sensor with a substantially linear configuration. The strain sensor is mounted on a transducer such that the strain sensor extends laterally across the transducer. The transducer has a base and a plurality of flaps joined at a first end to the base and supporting the strain sensor at a second end. The flaps translate acceleration in a predefined direction to strain in the strain sensor. Further embodiments have flaps defining an interrupted surface with greater height at the center and flaps that have features for enhancing the strain caused by acceleration.

Claims

1. An accelerometer comprising:

a strain sensor having a substantially linear configuration; and

a transducer joined to said strain sensor such that said strain sensor extends laterally across said transducer, said transducer having a base extending along said strain sensor and provided rigidity of said transducer in at least one direction perpendicular to a predefined direction, and a plurality of flaps joined at a first end to the base and supporting said strain sensor at a second end, the flaps being capable of translating acceleration in the predefined direction to strain in said strain sensor.

2. The device of claim 1 wherein said transducer flaps are angled from said transducer base toward a center of said strain sensor.

3. The device of claim 2 wherein said transducer has the same number of transducer flaps on either side of said strain sensor.

4. The device of claim 2 wherein said transducer flap second ends provide an interrupted surface with an increasing height from the transducer base at the center of said strain sensor for supporting said strain sensor.

5. The device of claim 1 wherein said transducer further has mounting portions on either end of said transducer, said strain sensor being joined to said transducer mounting portions.

6. The device of claim 1 wherein said transducer flap comprises:

a flap mass having an enhanced mass proximate the base of said transducer; and

a lever portion extending outward from said flap mass and having a sensor support for supporting said strain sensor, said lever portion having a reduced mass.

7. The device of claim 6 wherein said flap mass and said lever portion are structured with respect to a flap center of gravity such that the distance between the base and the flap center of gravity is less than the distance between the center of gravity and said lever portion sensor support.

8. The device of claim 7 wherein said transducer base and said flap mass have a first thickness and said lever portion has a second thickness, said second thickness being less than said first thickness.

9. The device of claim 6 wherein said flap further comprises a neck positioned between said flap mass and said base, said neck creating a reduced stiffness for deflection of said flap.

10. The device of claim 9 wherein said transducer base, said flap mass and said neck have a first thickness and said lever portion has a second thickness, said second thickness being less than said first thickness.

11. The device of claim 6 wherein said flap further comprises a weight positioned in said flap mass for increasing the mass of said flap mass.

12. The device of claim 1 wherein the strain sensor is a selected one of a fiber optic laser strain sensor, a fiber optic strain sensor, a foil strain sensor or a liquid filled tube strain sensor.

13. The device of claim 1 wherein the strain sensor is joined on said transducer under tension.