US3750023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Visual and rf beacon for miner{40 s hat with control circuit
Assignee: Friemann and Wolf GmbH
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Filing: 1971-08-05
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Granted: 1973-07-31
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Expires: 1991-08-05
Abstract
Abstract A lamp and a radio transmitter are connected in parallel across a battery in a miner''s hat to provide a visual and radiofrequency beacon enabling finding him in an emergency situation. In order to prevent the lamp from depleting the battery which would cut off the radio beacon, an involuntarily opened nonresettable switch is provided that disconnects the battery from everything but the transmitter. A voltage detector connected across the lamp senses when the voltage applied to this lamp drops below a predetermined level and closes a circuit to pass current through an electrically actuatable element for opening the switch. This element can be a minute squib or a fuse-type device forming the switch itself.
Inventors
- 👤 D Weissenborn
- 👤 O Bock
- 👤 N Werding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 07:56
CPC Classifications
H; H04; H04B; H04B13/00; H04B13/02; A; A42; A42B; A42B3/00; A42B3/04; A42B3/0406; A42B3/0433; A42B3/046; F; F21; F21L; F21L2/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
An electrical warning apparatus comprising: a battery; transmitter means connected across said battery and in circuit therewith for emitting a radio signal; a lamp connected across said battery and illuminable thereby; voltage-detector means connected to said battery for detecting a drop in voltage output thereof below a predetermined threshold level; and switch means including a rupturable element in series with said lamp across said battery and external of the circuit between said transmitter means, said voltage-detector means being connected to said switch means for rupturing said element to open the circuit to said lamp and extinguish same upon said voltage output of said battery dropping below said predetermined threshold level, while permitting said transmitter means to remain connected to said battery.
Claim 2
Dependent Claim
121 words
An electrical warning apparatus comprising: a battery; transmitter means connected across said battery and in circuit therewith for emitting a radio signal; a lamp connected across said battery and illuminable thereby; voltage-detector means connected to said battery for detecting a drop in voltage output thereof below a predetermined threshold level; and switch means including a rupturable element in series with said lamp across said battery and external of the circuit between said transmitter means, said voltage-detector means being connected to said switch means for rupturing said element to open the circuit to said lamp and extinguish same upon said voltage output of said battery dropping below said predetermined threshold level, while permitting said transmitter means to remain connected to said battery.
Claim 3
Dependent Claim
25 words
The apparatus defined in claim 1 wherein said voltage-detector and switch means present a resistance of at most 2 milliohms in series with said battery.
Claim 4
Dependent Claim
42 words
The apparatus defined in claim 1 wherein the switch means includes an electrically actuatable element connected to said voltage-detector means and operable to permanently break said rupturable element, said voltage-detector means being connected across said battery in series with said rupturable element.
Claim 5
Dependent Claim
55 words
The apparatus defined in claim 3 wherein said rupturable element includes a pair of contacts fused together and a spring biasing said contacts apart, said electrically actuatable element including a heater energized by an electric current and being connected electrically to said voltage-detector means for heating said contacts and enabling said contacts to pull apart.
Claim 6
Dependent Claim
19 words
The apparatus defined in claim 3 wherein said electrically actuatable element is a squib disposed adjacent said rupturable element.
Claim 7
Dependent Claim
33 words
The apparatus defined in claim 3 wherein said voltage-detector means includes a voltage-divider network connected across said lamp and at least one transistor connected to said network and to said electrically actuatable element.
Claim 8
Dependent Claim
37 words
The apparatus defined in claim 6 wherein said voltage-detector means includes a first transistor connected to said network as a sensor and at least one second transistor connected between said element and said electrically actuatable first transistor.
Claim 9
Dependent Claim
43 words
The apparatus defined in claim 7 wherein said voltage-detector means includes two such second transistors directly coupled with one another, one of said second transistors being connected to said first transistor and the other of said second transistors to said electrically actuatable element.
References Cited (Backward Citations)
US3181135A
Cited
US3321754A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |