Force transducer

• US 20030000317A1
• Filed: 08/14/2002
• Published: 01/02/2003
• Est. Priority Date: 02/22/2000
• Status: Active Grant

• Current Assignee: Office National D'Etudes et de Recherches Aerospatiales
• Original Assignee: Office National D'Etudes et de Recherches Aerospatiales
• Inventors: Bernard, Lecorre, Denis, Janiaud, Serge, Muller, Olivier, Le Traon
• Granted Patent: US 6,807,872 B2
• Time in Patent Office: Days
• US Class Current: 73/862.637
• CPC Class Codes: G01L 1/106 Constructional details

Abstract

The invention concerns a transducer constituting the sensitive member of a sensor whose frequency varies as a function of the intensity of force applied to it. The force transducer comprises a beam having length and rectangular cross-section with thickness and width and flexionally vibrating. The beam has a thickness reduced over a central portion of its length, its width remaining constant.

Claims

1. A force transducer comprising a beam (30) of length (L30) and having a rectangular cross-section of thickness (e) and width (l) vibrating flexionally, characterized in that the thickness (e) of said beam is reduced over a central portion (32) of its length and its width (l) is constant.

2. A force transducer according to claim 1, characterized in that the thickness (e2) in the middle of the length (L30) of the beam lies between one third and two thirds the greatest thickness (e1) at the ends of the beam.

3. A force transducer according to claim 2, characterized in that the beam (30) comprises, disposed along its length (L30), an odd integer number of parallelepiped-shaped portions (31, 32) whose thickness (e1, e2) decrease from the ends of the beam toward its central portion.

4. A force transducer according to claim 3, characterized in that there are three portions (31, 32) including two end portions (31) which are substantially identical and a central portion (32), the length (L2) of the central portion (32) lying between half and twice the length (L1) of each of the end portions (31).

5. A force transducer according to claim 4, characterized in that the thickness (e2) of the central portion (32) is substantially half the thickness (e1) of the end portions (31), and the length (L2) of the central portion (32) is substantially equal to the length (L1) of each of the end portions (31).

6. A force transducer according to claim 1 or 2, characterized in that the thickness of the beam decreases continuously from the ends of the beam to the middle of its length.

7. A force transducer according to any one of the preceding claims, characterized in that the means for imparting vibration to the beam comprise electrodes disposed on the beam in the vicinity of its ends.

8. A force transducer according to claim 7, characterized in that the end electrodes are connected by tracks having only an electrical connection role.