US3670301A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle anti-theft device
Assignee: Individual
•
Filing: 1971-03-15
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Granted: 1972-06-13
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Expires: 1991-03-15
Abstract
Abstract A light-weight portable alarm device is readily installed upon a mobile unit and sounds an alarm for a predetermined time interval in the event that an unauthorized person attempts to move the unit. The alarm is operable whether or not the wires of an associated electrical circuit are cut, and it is insensitive to changes in temperature, atmospheric pressures, moisture, dust or vibration.
Inventors
- 👤 Larry D Douglas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:29
CPC Classifications
G; G08; G08B; G08B13/00; B; B60; B60R; B60R25/00; B60R25/10; B60R25/1001; B60R25/1004
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
227 words
A vehicle anti-theft device; said vehicle having a body on which at least one of the devices may be removably mounted; said device comprising, in combination, a source of direct current, means for establishing a direct current relay circuit containing said source; said means comprising a key-operated switch, a relay electrically connected to said switch and consisting of a first relay contact, a second relay contact, an armature, and a springloaded arm for making engagement with said first relay contact and said second relay contact, and a normally closed switch in series with said armature and said source to effect direct current flow from said source of direct current through said keyoperated switch and said relay and said second relay contact upon the energization of said armature, and an alarm circuit comprising said direct current source; said alarm circuit being established upon the opening of said direct current circuit to cause de-energization of said armature and movement of said spring-loaded arm into engagement with said first relay contact and comprising a gate-controlled semiconductor rectifier consisting of a gate and a cathode and an anode, an electrical conductor connecting said first relay contact to said gate and said cathode of said rectifier, an audio alarm unit, and an electrical conductor connecting said anode of said rectifier to said audio alarm unit which is electrically connected to said source.
Claim 2
Dependent Claim
227 words
A vehicle anti-theft device; said vehicle having a body on which at least one of the devices may be removably mounted; said device comprising, in combination, a source of direct current, means for establishing a direct current relay circuit containing said source; said means comprising a key-operated switch, a relay electrically connected to said switch and consisting of a first relay contact, a second relay contact, an armature, and a springloaded arm for making engagement with said first relay contact and said second relay contact, and a normally closed switch in series with said armature and said source to effect direct current flow from said source of direct current through said keyoperated switch and said relay and said second relay contact upon the energization of said armature, and an alarm circuit comprising said direct current source; said alarm circuit being established upon the opening of said direct current circuit to cause de-energization of said armature and movement of said spring-loaded arm into engagement with said first relay contact and comprising a gate-controlled semiconductor rectifier consisting of a gate and a cathode and an anode, an electrical conductor connecting said first relay contact to said gate and said cathode of said rectifier, an audio alarm unit, and an electrical conductor connecting said anode of said rectifier to said audio alarm unit which is electrically connected to said source.
Claim 3
Dependent Claim
31 words
A vehicle anti-theft device as set forth in claim 1, and a current limiting resistor connected into said alarm circuit between said first relay contact and said gate of said rectifier.
Claim 4
Dependent Claim
52 words
A vehicle anti-theft device as set forth in claim 2, and a time-delay unit connected into said alarm circuit between said first relay contact and the output of said rectifier to compensate for the slow mechanical movement of said spring-loaded relay arm between said second relay contact and said first relay contact.
Claim 5
Dependent Claim
19 words
A vehicle anti-theft device as set forth in claim 1 wherein said normally closed switch is a mercury switch.
Claim 6
Dependent Claim
37 words
A vehicle anti-theft device as set forth in claim 1, and a flasher element connected into said alarm circuit for intermittently opening and closing said alarm circuit and thereby effect the intermittent sounding of said audio unit.
Claim 7
Dependent Claim
21 words
A vehicle anti-theft device as set forth in claim 1, and a plurality of visual elements connected into said alarm circuit.
Claim 8
Dependent Claim
54 words
A vehicle anti-theft device as set forth in claim 4, and a plurality of said mercury switches connected into said direct current relay circuit and mounted in a plurality of places on said body of the vehicle for establishing said alarm circuit when at least one of said plurality of mercury switches is opened.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-13 | 1975-12-13 | 1976-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-13 | 1979-12-13 | 1980-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-13 | 1983-12-13 | 1984-06-13 | $7700.00 | Window Closed / Lapsed |