Patent US3774108A successfully refreshed from Google Patents.
US3774108A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic potential detector
Assignee: FRL Inc
•
Filing: 1971-12-13
•
Granted: 1973-11-20
•
Expires: 1991-12-13
Abstract
Abstract Instrument for detecting presence of energized conductors and determining whether conductors are energized by detecting electrostatic fields produced thereby. An attenuator assembly provides means for adjusting the sensitivity of the instrument, and an on/off switch is arranged in such manner that the instrument is in its most sensitive condition when first turned on.
Inventors
- 👤 A Ogilvie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:02
CPC Classifications
G; G01; G01R; G01R29/00; G01R29/24; G01R5/00; G01R5/28
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
151 words
A self-contained portable device of a size readily held in the hand for detecting the presence of an electrostatic potential comprising: an axially extending tubular housing, an electrostatic sensing element mounted at one end of said housing, a power source disposed within said housing, alarm means carried by said housing, electrically energizable circuit means disposed within said housing for actuating said alarm means to indicate an alarm condition when said sensing element is exposed to an electrostatic field of predetermined strength, an axially elongated attenuator sleeve disposed coaxially of said housing and movable between extended and retracted positions relative to said sensing element, the sensitivity of the device increasing as said sleeve is moved toward its retracted position, and switch means operably connected to said sleeve for connecting said circuit means to said power source to energize said circuit means when said sleeve is moved away from its fully retracted position.
Claim 2
Dependent Claim
151 words
A self-contained portable device of a size readily held in the hand for detecting the presence of an electrostatic potential comprising: an axially extending tubular housing, an electrostatic sensing element mounted at one end of said housing, a power source disposed within said housing, alarm means carried by said housing, electrically energizable circuit means disposed within said housing for actuating said alarm means to indicate an alarm condition when said sensing element is exposed to an electrostatic field of predetermined strength, an axially elongated attenuator sleeve disposed coaxially of said housing and movable between extended and retracted positions relative to said sensing element, the sensitivity of the device increasing as said sleeve is moved toward its retracted position, and switch means operably connected to said sleeve for connecting said circuit means to said power source to energize said circuit means when said sleeve is moved away from its fully retracted position.
Claim 3
Dependent Claim
67 words
A device for detecting an electrostatic potential as in claim 1 wherein said sleeve includes an electrically insulative portion and an electrically conductive portion and said switch means includes a pair of electrical contacts which engage the insulative portion of the sleeve when said sleeve is in its fully retracted position and engage the conductive portion of the sleeve when said sleeve is in its other positions.
Claim 4
Dependent Claim
81 words
A device for detecting an electrostatic potential as in claim 1 wherein said circuit means includes an astable multivibrator which normally oScillates between first and second output states when energized, said multivibrator being connected to said alarm means in such manner that said alarm means is actuated when said multivibrator is in its first state, said sensing element being connected for holding said multivibrator in said first state when said element is exposed to an electrostatic field of said predetermined strength.
Claim 5
Dependent Claim
129 words
In a self-contained electrostatic potential detector of a size suitable to be held in the hand, an axially extending body member, an electrostatic sensing element carried by said body member, a power source carried by said body member, alarm means carried by said body member, circuit means energized by said power source connected to said alarm means and to said sensing element for actuating said alarm means to indicate an alarm condition when said sensing element is exposed to an electrostatic field of predetermined strength, adjustable attenuator means carried by said body member for attentuating the field to which said sensing element is exposed, and switch means operably connected to the attenuator means for controlling the energization of the circuit means according to the position of the attenuator means.
Claim 6
Dependent Claim
129 words
In a self-contained electrostatic potential detector of a size suitable to be held in the hand, an axially extending body member, an electrostatic sensing element carried by said body member, a power source carried by said body member, alarm means carried by said body member, circuit means energized by said power source connected to said alarm means and to said sensing element for actuating said alarm means to indicate an alarm condition when said sensing element is exposed to an electrostatic field of predetermined strength, adjustable attenuator means carried by said body member for attentuating the field to which said sensing element is exposed, and switch means operably connected to the attenuator means for controlling the energization of the circuit means according to the position of the attenuator means.
Claim 7
Dependent Claim
52 words
An electrostatic potential detector as in claim 4 wherein said attenuator means includes an attenuator sleeve disposed coaxially of said body member and movable between extended and retracted positions relative to said sensing element, said sleeve providing greater attenuation of the electrostatic field as it is moved toward its fully extended position.
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) | 1976-11-19 | 1977-05-21 | 1977-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-19 | 1981-05-21 | 1981-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-19 | 1985-05-21 | 1985-11-20 | $7700.00 | Window Closed / Lapsed |