Patent US3754225A successfully refreshed from Google Patents.
US3754225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Portable equipment security system
Assignee: Reaction Instruments Inc
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Filing: 1971-06-03
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Granted: 1973-08-21
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Expires: 1991-06-03
Abstract
Abstract A portable security equipment system having a magnet means mounted on the equipment to be monitored. The magnetic means is supported by means such as a spring so as to vibrate or oscillate at a substantially fixed frequency in response to acceleration caused by movement of the equipment. A magnetometer is located so as to detect the modulation of the magnetic field caused by the vibration of the magnet.
Inventors
- 👤 D Gleason
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:27
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/14; G08B13/1436
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
92 words
A system for detecting transportation of portable equipment comprising a housing for mounting on said equipment; at least one permanent magnetic means; elastic means for supporting said permanent magnetic means in said housing; said elastic means allowing said permanent magnetic means to vibrate at a predetermined frequency in response to minimal accelerations of said equipment; and magnetic field detection means without said housing and remote from said magnetic means and responsive to said predetermined frequency of vibration of said magnetic means, said detection means being nonresponsive to a substantially stable magnetic field.
Claim 2
Independent Claim
92 words
A system for detecting transportation of portable equipment comprising a housing for mounting on said equipment; at least one permanent magnetic means; elastic means for supporting said permanent magnetic means in said housing; said elastic means allowing said permanent magnetic means to vibrate at a predetermined frequency in response to minimal accelerations of said equipment; and magnetic field detection means without said housing and remote from said magnetic means and responsive to said predetermined frequency of vibration of said magnetic means, said detection means being nonresponsive to a substantially stable magnetic field.
Claim 3
Dependent Claim
53 words
The system of claim 1 wherein said permanent magnetic means comprises a plurality of magnets; and said elastic means comprises a plurality of springs equal in number to said magnets, said springs supporting said magnets so that each of said magnets vibrates at a predetermined frequency different from each of said other magnets.
Claim 4
Dependent Claim
25 words
The system of claim 2 wherein said magnetic field detection means comprises a detector for detecting the frequency of vibration of each of said magnets.
Claim 5
Dependent Claim
54 words
The system of claim 1 wherein said magnetic detection means comprises a plurality of magnetometers having their axes of favorable response positioned in varying directions whereby at least one of said magnetometers will respond to the magnetic field created by the vibration of said magnetic means regardless of the orientation of said magnetic means.
Claim 6
Dependent Claim
22 words
The system of claim 1 wherein said elastic means comprises a spring steel reed mounted between said magnetic means and said housing.
Claim 7
Dependent Claim
41 words
The system of claim 1 further comprising a weight; a spring steel reed for supporting said weight in said housing; a finger extending outwardly from said magnetic means; a pick extending outwardly from said weight in plucking relationship with said finger.
Claim 8
Dependent Claim
31 words
The system of claim 1 further comprising a soft iron element mounted within said housing whereby said magnetic means moves to and away from said element as said magnetic means vibrates.
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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) | 1976-08-20 | 1977-02-19 | 1977-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-20 | 1981-02-19 | 1981-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-20 | 1985-02-19 | 1985-08-21 | $7700.00 | Window Closed / Lapsed |