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US4754644A Expired / Lapsed US ⏱️ 0.0 years remaining

Variable-reluctance accelerometer

Assignee: ITW Fastex Italia SpA
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Filing: 1987-03-03
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Granted: 1988-07-05
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Expires: 2007-03-03
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Abstract

Abstract An accelerometer comprising a permanent magnet which, when idle, is maintained dynamically balanced by virtue of magnetic fields acting on opposite sides in relation to its poles, and which is designed to travel along a respective guide. The accelerometer has a coil arranged coaxially in relation to the traveling direction of the magnet, and is designed to generate an electric signal, the intensity of which depends on the relative acceleration of the coil in relation to the magnet and in the traveling direction of the same.

Inventors

  • 👤 Mario Valentini

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 05:16
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/11

Claims Analysis

Total Claims: 5
Claim 1
Independent Claim 160 words
An accelerometer comprising a main permanent magnet, a guide housing said main magnet and enabling it to travel in a given prearranged direction, first and second magnetic field generating means wherein the respective north and south poles are arranged facing identical north and south poles on said main magnet, said first and second magnetic field generating means exerting respective repelling forces on the said main magnet which, when idle, maintain the said main magnet dynamically balanced inside said guide, a coil located between said first and second magnetic field generating means and coaxial in relation to said main magnet and in said traveling direction, an input signal means or providing a constant supply current to said coil including a common base connected transistor having a resistor-capacitor network connected in series across its emitter-base terminal and said coil connected in parallel with the resistor of said resistor-capacitor network, and signal comparator means for comparing the output signal generated by said coil.
Claim 2
Dependent Claim 160 words
An accelerometer comprising a main permanent magnet, a guide housing said main magnet and enabling it to travel in a given prearranged direction, first and second magnetic field generating means wherein the respective north and south poles are arranged facing identical north and south poles on said main magnet, said first and second magnetic field generating means exerting respective repelling forces on the said main magnet which, when idle, maintain the said main magnet dynamically balanced inside said guide, a coil located between said first and second magnetic field generating means and coaxial in relation to said main magnet and in said traveling direction, an input signal means or providing a constant supply current to said coil including a common base connected transistor having a resistor-capacitor network connected in series across its emitter-base terminal and said coil connected in parallel with the resistor of said resistor-capacitor network, and signal comparator means for comparing the output signal generated by said coil.
Claim 3
Dependent Claim 27 words
An accelerometer as defined in claim 1, wherein said signal comparator means comprises several threshold comparators, each having a comparing input connected to a respective reference voltage.
Claim 4
Dependent Claim 26 words
An accelerometer as defined in claim 2 further comprising a number of optical signaling means, each connected to the output of one of said threshold comparators.
Claim 5
Dependent Claim 18 words
An accelerometer as defined in claim 3, wherein each of said optical signaling means comprises a light-emitting diode.

References Cited (Backward Citations)

US2852243A Cited
US3100292A Cited
US3129347A Cited
US3483759A Cited
US3987392A Cited
US4446741A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-07-05 1992-01-04 1992-07-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-07-05 1996-01-04 1996-07-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-07-05 2000-01-04 2000-07-05 $7700.00 Window Closed / Lapsed

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