Patent EA-000375-B1 (EA)
Title: Monolithic acceleration transducer and accelerometer, comprising transducers
Inventor: LE TRAON OLIVER
IPC: G01P15/097
Filed: 1996-09-23
Abstract: 1. A monolithic transducer including a fixed portion (1e1), movable massive portion (2e1, 4e1) and a resonator (3e1) having ends secured to the movable massive portion, wherein it further comprises a second movable massive portion secured to the other portion of said resonator, a flexible frame (5e1) surrounding the two movable massive portions, and two linking members (6e1, 7e1) connecting the frame (5e1) to the second movable massive portion (4e1) and the fixed portion (1e1). 2. flexible frame has a rectangular form and includes two portions, passing essentially parallel to said transducer, and two other portions passing essentially perpendicular to said transducer, and connected correspondingly to said second movable massive portion the and to a fixed portion by means of said and the second linking members, and said first linking member is wider than said second movable massive portion, and said second linking member has the width less than the length of said other portions and it is preferable that at least one of said linking members has a cross-section essentially equal to the cross-section of the frame portions. 3. Transducer according to Claim 1 or 2, wherein said movable massive portions, flexible frame, resonator, and linking elements have one plane of symmetry perpendicular to the frame plane and said linking elements are arranged accordingly on intersections of the frame and said plane of symmetry. 4. Transducer according to one of the preceding Claims comprising two coplanery plates, each of which has end portions, connected to said movable massive portions and disposed on both sides of said resonator. 5. Transducer according to Claim 4, wherein the length of said plates is shorter than the length of said resonator and, preferably being from 0.1 to 0.5 of the resonator length. 6. Transducer according to Claim 4 or 5, wherein said plates are arranged in the plane perpendicular to said resonator and in the middle of the resonator length. 7. Transducer according to one 4-6 Claims, wherein said plate are thinner than said movable massive portions and are levelled along the general side of said two movable massive portions, and said resonator is levelled along the other general side of two movable massive portions, while said plates and resonator have the same thickness, corresponding to the thickness of said movable massive portions. 8. Transducer according to one of 1-7 Claims, wherein said fixed portion is disposed inside said frame. 9. Transducer according to one of 1-7 Claims, wherein said fixed frame has a U-shaped form, surrounding the frame, except the frame portion connected to said first linking element, and includes the main annular portion, the middle portion of which is connected to said second linking member, and two branches, connected by corresponding end portions to the main portion to fix the transducer to the base. 10. Transducer according to one of 1-7 Claims, wherein comprising two electrodes, supported by said resonator, two contact zones, supported by said fixed portion, and two conductive bands, and supported by said second movable massive portion, said first linking element, said frame, said second linking element and said fixed portion to connect two electrodes to two corresponding contact zones. 11. Accelerometer comprising said first and second monolithic acceleration transducers according to any of the preceding Claims, wherein the position of the first and second transducers are symmetrical to each other towards the axis (Y' Y), parallel axis, passing through the end portions of the first transducer resonator, with the fixed portions being rigidly interconnected. 12. Accelerometer according to Claim 11, wherein said transducers are arranged symmetrically to each other towards the plane, parallel to coplanery sides of said movable massive portions each of the transducers 13. Accelerometer according to Claim 11, wherein said movable massive portions of said frame and said fixed portions of said transducers have coplanery sides, while said transducers are preferably arranged symmetrically arranged to each other towards the axis (Y' Y), parallel to the coplanery sides.