Patent US3760402A successfully refreshed from Google Patents.
US3760402A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical installation for protecting movable items
Assignee: Cerberus AG
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Filing: 1972-04-03
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Granted: 1973-09-18
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Expires: 1992-04-03
Abstract
Abstract An electrical installation for protecting articles suspended by suspension means against theft or damage, such installation comprising at least one force transducer means embodying at least one piezo-electric element. The force transducer means is disposed at the suspension means in such a way that it is normally loaded with a force of a steady-state value formed by the weight of the article to be protected. The piezo-electric element possesses a main sensitivity direction and is disposed in such a way that this main sensitivity direction is essentially identical with the direction of the force formed by the weight of the article and applied to said force transducer means. There is also provided charge amplifier means associated with and coupled with said force transducer means for generating a signal when the force acting upon siad force transducer means deviates from the steady-state value by a predetermined small amount either in the sense of an increase or a decrease, and an alarm device means is coupled with and triggered by said signal from said charge amplifier means.
Inventors
- 👤 R Magerle
- 👤 F Datwyler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:34
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/02; G08B13/14; G08B13/1472
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
189 words
An electrical installation for protecting suspended articles comprising track means positionable along a wall or ceiling of a room for receiving a compact detector unit therein, said compact detector unit comprising force transducer means couplEd with a charge amplifier means, means provided on said detector unit for suspending the article to be protected and for loading said force transducer with a force of a steady-state value caused by the weight of said suspended article, said force transducer means including piezo-electric element with a main sensitivity direction oriented in a direction essentially identical with the direction of the force induced by the weight of the article suspended, said coupled charge amplifier means for generating a signal when the force acting upon said force transducer means deviates from said steady-state value by a predetermined value, said track means carrying conductor elements electrically connected to alarm means and constructed with openings to permit variable positioning of said compact detector unit along the length of said track, whereby one or more objects of varying size and weight can be suspended against a wall or the like and readily connected into an existing system.
Claim 2
Dependent Claim
189 words
An electrical installation for protecting suspended articles comprising track means positionable along a wall or ceiling of a room for receiving a compact detector unit therein, said compact detector unit comprising force transducer means couplEd with a charge amplifier means, means provided on said detector unit for suspending the article to be protected and for loading said force transducer with a force of a steady-state value caused by the weight of said suspended article, said force transducer means including piezo-electric element with a main sensitivity direction oriented in a direction essentially identical with the direction of the force induced by the weight of the article suspended, said coupled charge amplifier means for generating a signal when the force acting upon said force transducer means deviates from said steady-state value by a predetermined value, said track means carrying conductor elements electrically connected to alarm means and constructed with openings to permit variable positioning of said compact detector unit along the length of said track, whereby one or more objects of varying size and weight can be suspended against a wall or the like and readily connected into an existing system.
Claim 3
Dependent Claim
22 words
An electrical installation as defined in claim 1, wherein said track has openings at regular intervals for allowing passage of suspension cables.
Claim 4
Dependent Claim
55 words
An electrical installation as defined in claim 1, further comprising a track having a cover and mounted at a wall or the ceiling of a room, said compact unit being mounted behind said cover in said track, and wherein several of said compact units are coupled to said alarm device in parallel with one another.
Claim 5
Dependent Claim
39 words
An electrical installation as defined in claim 1, wherein said charge amplifier means generates a signal only if said force deviates from said steady-state value by a predetermined amount and within a period of time less than 10 seconds.
Claim 6
Dependent Claim
23 words
An installation as defined in claim 1, wherein said charge amplifier means has a lower frequency transmission limit between 0.1 and 2 Hz.
Claim 7
Dependent Claim
30 words
An electrical installation as defined in claim 1, wherein said force transducer means and said charge amplifier means coupled therewith have an upper frequency transmission limit less than 500 Hz.
Claim 8
Dependent Claim
53 words
An electrical installation as defined in claim 1, wherein said force transducer means comprises two piezo-electric elements, and wherein said force formed by the weight of the article to be protected acts at a point between said two piezo-electric elements in the same direction as the main sensitivity direction of the piezo-electric elements.
Claim 9
Dependent Claim
32 words
An electrical installation as defined in claim 1, wherein said charge amplifier means comprises a field-effect transistor having a gate electrode which is connected to one electrode each of said piezo-electric elements.
Claim 10
Dependent Claim
97 words
An electrical installation as defined in claim 1, wherein the input voltage at the gate electrode of said field-effect transistor is normally zero as long as said piezo-electric element is loaded by the steady-state value of the weight of the article to be protected and that said field-effect transistor is operated as a linear amplifier in the surroundings of an input voltage being zero and that the output of said field-effect transistor is connected with a threshold detector having one threshold which is positive and another threshold which is negative relative to an input voltage of zero.
Claim 11
Dependent Claim
45 words
An electrical installation as defined in claim 9, wherein said alarm device means is connected with said charge amplifier means and emits an alarm signal when the input voltage of said field-effect transistor exceeds the first threshold value or drops below the second threshold value.
Claim 12
Dependent Claim
36 words
An electrical installation as defined in claim 1 wherein said compact detector suspending means comprises a connector for receiving a cable attached to said article being protected, said compact detector unit being positioned above said cable.
Claim 13
Dependent Claim
25 words
An electrical installation as defined in claim 11 further including lockable cover means attached to said track for totally enclosing said compact detector unit therein.
Claim 14
Dependent Claim
32 words
An electrical installation as defined in claim 12, furtheR including safety switch means disposed at said track, said safety switch activating an alarm signal when said cover is removed from said track.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-17 | 1977-03-19 | 1977-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-17 | 1981-03-19 | 1981-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-17 | 1985-03-19 | 1985-09-18 | $7700.00 | Window Closed / Lapsed |