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US4795123A Expired / Lapsed US ⏱️ 0.0 years remaining

Wideband electromagnetic damping of vibrating structures

Assignee: United States Department of the Air Force
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Filing: 1987-05-14
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Granted: 1989-01-03
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Expires: 2007-05-14
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Abstract

Abstract The damping of vibrations in a mechanical structure is accomplished while minimizing the impact on the design and operation of the structure through the use of a plurality of attachable vibration damping elements. Each vibration damping element contains: an accelerometer, an integrator, mixer, power amplifier, and a force actuator. The accelerometer measures the motion of the vibration in the structure at its attachment point and produces an acceleration measurement signal. The integrator integrates the acceleration measurement signal to produce a velocity measurement signal. The mixer produces a composite motion signal by mixing the acceleration measurement signal with the velocity measurement signal. The power amplifier adjusts the phase and amplitude of the composite motion signal to drive the force actuator to damp the sensed vibration along one dimension at the attachment point of the force actuator. By placing three vibration damping element at right angles to each other at a location on the structure, three dimensional vibration damping is obtained at that point.

Inventors

  • 👤 Robert L. Forward
  • 👤 William S. Griffin

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 23:22
CPC Classifications
F; F16; F16F; F16F15/00; F16F15/02

Claims Analysis

Total Claims: 2
Claim 1
Independent Claim 239 words
A vibration damping system which damps motion-induced vibration in a mechanical structure using a plurality of vibration damping elements, each of which forms an axis by being fixed to said mechanical structure at a contact point, each of said vibration damping elements producing a mechanical force to dampen vibration along said axis at said point of contact, said plurality of vibration damping elements thereby collectively damping said motion-induced vibration in said mechanical structure, each of said vibration damping elements comprising: an accelerometer which is housed in said vibration damping element and which produces an acceleration measurement signal by measuring acceleration along said axis of its vibration damping element; an integrator which produces a velocity measurement signal by integrating said acceleration measurement signal received from said accelerometer; a mixer which produces a combined motion signal by mixing said velocity measurement signal received from said integrator with said acceleration measurement signal received from said accelerometer; a power amplifier which produces a composite motion signal by amplifying and adjusting the phase of said combined motion signal received from said mixer; a means for attaching said vibration damping element to said mechanical structure; and a force actuator which contains said accelerometer and is attached to said structure by said attaching means at one end, and which is electrically attached to said power amplifier at its other end, said force actuator receiving and translating said composite motion signal into mechanical force to dampen vibration.
Claim 2
Dependent Claim 239 words
A vibration damping system which damps motion-induced vibration in a mechanical structure using a plurality of vibration damping elements, each of which forms an axis by being fixed to said mechanical structure at a contact point, each of said vibration damping elements producing a mechanical force to dampen vibration along said axis at said point of contact, said plurality of vibration damping elements thereby collectively damping said motion-induced vibration in said mechanical structure, each of said vibration damping elements comprising: an accelerometer which is housed in said vibration damping element and which produces an acceleration measurement signal by measuring acceleration along said axis of its vibration damping element; an integrator which produces a velocity measurement signal by integrating said acceleration measurement signal received from said accelerometer; a mixer which produces a combined motion signal by mixing said velocity measurement signal received from said integrator with said acceleration measurement signal received from said accelerometer; a power amplifier which produces a composite motion signal by amplifying and adjusting the phase of said combined motion signal received from said mixer; a means for attaching said vibration damping element to said mechanical structure; and a force actuator which contains said accelerometer and is attached to said structure by said attaching means at one end, and which is electrically attached to said power amplifier at its other end, said force actuator receiving and translating said composite motion signal into mechanical force to dampen vibration.

References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-01-03 1992-07-04 1993-01-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-01-03 1996-07-04 1997-01-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-01-03 2000-07-04 2001-01-03 $7700.00 Window Closed / Lapsed

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