Patent US3745549A successfully refreshed from Google Patents.
US3745549A
Expired / Lapsed
US
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Proximity alarm
Assignee: CRANE PROD Mfg CO Inc
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Filing: 1971-04-19
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Granted: 1973-07-10
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Expires: 1991-04-19
Abstract
Abstract A control device in a proximity alarm system gives warning when an object enters an electrostatic field located around an energized power line. The alarm system itself comprises antenna means for sensing the presence of the electrostatic field thereby inducing an alternating current potential therein. A switching circuit and an induced signal control circuit are electrically connected to each other. The switching circuit includes antenna sensitivity control, test circuitry and alarm circuitry. The induced signal control circuit includes amplifier means, halfwave voltage doubling means, oscillating means, power supply voltage regulating means and frequency filtering means. In a specific embodiment, the switching circuit and the induced signal control circuit are located in a casing composed of a nonmagnetic material. The induced signal control circuit is encapsulated in a resinous material and is removably mounted within the casing.
Inventors
- 👤 R Jepperson
- 👤 C Simmonds
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:07
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/22; G08B13/26; G08B21/00; G08B21/02; G08B21/18; G08B21/182
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
105 words
In a proximity alarm which gives warning when an object enters an electrostatic field, the combination comprising: a. a casing composed of a non-magnetic material, b. a switching circuit portion including test circuitry and alarm circuitry disposed in said casing, c. a signal control circuit portion responsive to any induced signal received from the electrostatic field to form an oscillating response signal effective to operate an alarm, d. said signal control circuit portion being encapsulated and disposed adjacent the switching circuit and being removably mounted in said casing, and e. plug means for electrically connecting the switching circuit portion to the signal control circuit portion.
Claim 2
Dependent Claim
105 words
In a proximity alarm which gives warning when an object enters an electrostatic field, the combination comprising: a. a casing composed of a non-magnetic material, b. a switching circuit portion including test circuitry and alarm circuitry disposed in said casing, c. a signal control circuit portion responsive to any induced signal received from the electrostatic field to form an oscillating response signal effective to operate an alarm, d. said signal control circuit portion being encapsulated and disposed adjacent the switching circuit and being removably mounted in said casing, and e. plug means for electrically connecting the switching circuit portion to the signal control circuit portion.
Claim 3
Dependent Claim
36 words
In an alarm system as defined in claim 1 wherein the signal control circuit portion includes variable resistance means electrically connected to transistor means for establishing and maintaining predetermined induced response characteristics within said transistor means.
Claim 4
Dependent Claim
52 words
In an alarm system as defined in claim 1 wherein the signal control circuit portion includes amplifier means having transistor means for receiving any induced signal emanating from the electrostatic field and a variable resistance means electrically connected to the transistor means for establishing a predetermined biasing potential within said transistor means.
Claim 5
Dependent Claim
44 words
In an alarm system as defined in claim 3 wherein said transistor means is a field effect transistor and said induced signal is received at the gate of the transistor and said variable resistance means is electrically connected to the source of the transistor.
Claim 6
Dependent Claim
38 words
In an alarm system as defined in claim 3 wherein the signal control circuit portion includes filtering means having means electrically connected to the output of the transistor means for filtering extraneous alternating current frequency from the system.
Claim 7
Dependent Claim
30 words
In an alarm system as defined in claim 5 wherein said filtering means includes means for applying the filtered extraneous alternating current frequency to the casing thereby effecting grounding thereof.
Claim 8
Dependent Claim
42 words
In an alarm system as defined in claim 1 wherein the signal control circuit portion includes oscillating means having a uni-junction transistor and a variable resistance means electrically connected to the uni-junction transistor for establiShing a predetermined firing point in said transistor.
Claim 9
Dependent Claim
44 words
In an alarm as defined in claim 1 wherein the signal control circuit portion includes oscillating means and power supply voltage regulating means which controls varying voltage supply to the alarm system thereby maintaining the frequency of the oscillating means at a predetermined level.
Claim 10
Dependent Claim
80 words
In an alarm system as defined in claim 1 wherein the signal control circuit portion is responsive to an induced voltage signal and includes means for amplifying the induced voltage signal, means for converting the amplified induced signal to a doubled half-wave form, oscillating means for producing short duration pulses in response to said double half-wave form, and means for stretching the width of the short duration pulses from the oscillating means to provide satisfactory energizing of the alarm circuitry.
Claim 11
Dependent Claim
156 words
A proximity alarm system which gives warning when a projection from a vehicle enters an electrostatic field located around an energized power line comprising: a. alarm means electrically connected to a normally de-energized relay, b. antenna means for sensing the presence of the electrostatic field, c. means for receiving and amplifying an induced signal sensed by the antenna means, d. means for converting the amplified induced signal to a doubled half-wave form, e. oscillating means for producing short duration pulses in response to said doubled half-wave form, f. means for stretching the width of the short duration pulse from the oscillating means to provide satisfactory energizing of the alarm means, g. means for energizing the relay with the stretched pulse thereby actuating the alarm means, h. means for providing power supply voltage from the vehicle to the alarm system, and i. means for regulating varying power voltage supplied to the alarm system at a predetermined level.
Claim 12
Dependent Claim
156 words
A proximity alarm system which gives warning when a projection from a vehicle enters an electrostatic field located around an energized power line comprising: a. alarm means electrically connected to a normally de-energized relay, b. antenna means for sensing the presence of the electrostatic field, c. means for receiving and amplifying an induced signal sensed by the antenna means, d. means for converting the amplified induced signal to a doubled half-wave form, e. oscillating means for producing short duration pulses in response to said doubled half-wave form, f. means for stretching the width of the short duration pulse from the oscillating means to provide satisfactory energizing of the alarm means, g. means for energizing the relay with the stretched pulse thereby actuating the alarm means, h. means for providing power supply voltage from the vehicle to the alarm system, and i. means for regulating varying power voltage supplied to the alarm system at a predetermined level.
Claim 13
Dependent Claim
24 words
An alarm system as defined in claim 10 wherein said amplifier means includes filtering means for filtering extraneous alternating current frequencies from the system.
Claim 14
Dependent Claim
98 words
An alarm system which gives warning when an object enters an electrostatic field comprising: a. antenna means for sensing the presence of said field which thereby induces an alternating current potential therein, b. a switching circuit including means for controlling the sensitivity of the antenna, circuit means for testing the alarm system, and alarm circuit means, c. a signal control circuit responsive to any induced signal received from the electrostatic field to form an oscillating response signal effective to operate the alarm circuit means, and d. means for electrically connecting the switching circuit to the signal control circuit.
Claim 15
Dependent Claim
98 words
An alarm system which gives warning when an object enters an electrostatic field comprising: a. antenna means for sensing the presence of said field which thereby induces an alternating current potential therein, b. a switching circuit including means for controlling the sensitivity of the antenna, circuit means for testing the alarm system, and alarm circuit means, c. a signal control circuit responsive to any induced signal received from the electrostatic field to form an oscillating response signal effective to operate the alarm circuit means, and d. means for electrically connecting the switching circuit to the signal control circuit.
Claim 16
Dependent Claim
44 words
An alarm system as defined in claim 12 wherein said signal control circuit is encapsulated in a resinous material and disposed in a casing composed of a nonmagnetic material and said switching circuit is disposed in said casing adjacent the encapsulated signal control circuit.
Claim 17
Dependent Claim
35 words
An alarm system as defined in claim 13 wherein said encapsulated signal control circuit is removably mounted in said casing and said circuit connecting means includes a plug means having a plurality of connecting pins.
Claim 18
Dependent Claim
127 words
A proximity alarm control device comprising: a. a casing composed of a non-magnetic material, b. means for receiving an induced input voltage from an electrostatic field around energized power lines, c. a switching circuit disposed in said casing, d. said switching circuit including circuit means for testing the device, alarm circuit means and means for providing a power supply voltage to the control device, e. a signal control circuit responsive to the induced input voltage from the electrostatic field to form an oscillating response signal effective to operate the alarm circuit means, f. said signal control circuit being encapsulated and disposed adjacent the switching circuit and being remOvably mounted in said casing, and g. plug means for electrically connecting the switching circuit to the signal control circuit.
Claim 19
Dependent Claim
127 words
A proximity alarm control device comprising: a. a casing composed of a non-magnetic material, b. means for receiving an induced input voltage from an electrostatic field around energized power lines, c. a switching circuit disposed in said casing, d. said switching circuit including circuit means for testing the device, alarm circuit means and means for providing a power supply voltage to the control device, e. a signal control circuit responsive to the induced input voltage from the electrostatic field to form an oscillating response signal effective to operate the alarm circuit means, f. said signal control circuit being encapsulated and disposed adjacent the switching circuit and being remOvably mounted in said casing, and g. plug means for electrically connecting the switching circuit to the signal control circuit.
Claim 20
Dependent Claim
34 words
An alarm device as defined in claim 15 wherein the signal control circuit includes variable resistance means connected to transistor means for establishing and maintaining predetermined induced signal response characteristics in said transistor means.
Claim 21
Dependent Claim
51 words
A control device as defined in claim 15 wherein the induced input voltage receiving means is the base of a transistor means and the signal control circuit includes amplifier means having a variable resistance means electrically connected to said transistor means for establishing a predetermined biasing potential within said transistor means.
Claim 22
Dependent Claim
43 words
A control device as defined in claim 17 wherein said transistor means is a field effect transistor and said induced voltage is received at the gate of the transistor, and said variable resistance means is electrically connected to the source of said transistor.
Claim 23
Dependent Claim
38 words
A control device as defined in claim 17 wherein the signal control circuit includes filtering means having means electrically connected to the output of the transistor means for filtering extraneous alternating current frequency from the signal control circuit.
Claim 24
Dependent Claim
41 words
A control device as defined in claim 15 wherein the signal control circuit includes oscillating means having a uni-junction transistor and a variable resistance means electrically connected to the base of the uni-junction transistor for establishing a predetermined firing point thereof.
Claim 25
Dependent Claim
46 words
A control device as defined in claim 15 wherein the signal control circuit includes oscillating means and said power supply voltage regulating means control varying voltage in the supply to the alarm circuit means to maintain the frequency of the oscillating means at a predetermined level.
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) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |