US3821639A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Socket ground line testing apparatus
Assignee: LANGIS P DE
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Filing: 1973-03-19
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Granted: 1974-06-28
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Expires: 1993-03-19
Abstract
Abstract Apparatus to test the quality of socket wiring, namely, whether or not a supply socket has a grounded line terminal and the quality of the grounding connection. A load resistance is connected through a first double-pole, double-throw switch and a second double-pole, double throw switch to a 3-prong plug, and a meter is connected so as to measure either the line voltage or the voltage drop in the line grounding system. If there is no ground connection at the supply socket, the meter reads the line voltage. If there is a ground connection at the supply socket, the meter will give a relatively low reading, namely, the voltage drop in the line grounding system, in one switching configuration, and will give the line voltage in another switching configuration.
Inventors
- 👤 Langis P De
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:41
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G01R27/00; G01R27/02; G01R27/16; G01R27/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
315 words
A test apparatus for use with a supply socket of the type having a pair of female line terminals with respective supply line wires, one of which is a power line ground wire, connected to said terminals and a female ground terminal with a system ground conductor presumably connected to said ground terminal, a male plug having line prongs engageable with said female line terminals and a ground plug prong engageable with said female ground terminal, a first double-pole, double-throw reversing switch having its poles connected to said line prongs and having diagonally connected respective pairs of stationary contacts, a load impedance and meter connected in a series circuit to define a common junction, circuit means connecting the outside terminal of the load impedance in said series circuit to one pair of diagonally-connected stationary contacts, a second double-pole, double-throw reversing switch having its poles respectively connected to said common junction and the outside terminal of said meter in said series circuit and having diagonally-connected pairs of stationary contacts, the junction-connected pole being engageable with one of one pair of the last-named diagonallyconnected stationary contacts in one closing position thereof and with one of the other pair oF the last-named diagonally-connected stationary contacts in its opposite closing position, circuit means connecting the ground prong to one pair of diagonallyconnected contacts including said stationary contact of the second double-pole, double-throw switch engageable by the junction-connected pole in said one closing position of said second switch, and circuit means connecting the stationary contact engageable by said junction-connected pole in said opposite closing position to the other pair of diagonallyconnected contacts of the first double-pole, double-throw switch, whereby the system ground wire and the power line ground wire may be individually tested by operating the second double-pole, double-throw switch to apply current drawn by said load impedance to either said system ground wire or said power line ground wire.
Claim 2
Dependent Claim
315 words
A test apparatus for use with a supply socket of the type having a pair of female line terminals with respective supply line wires, one of which is a power line ground wire, connected to said terminals and a female ground terminal with a system ground conductor presumably connected to said ground terminal, a male plug having line prongs engageable with said female line terminals and a ground plug prong engageable with said female ground terminal, a first double-pole, double-throw reversing switch having its poles connected to said line prongs and having diagonally connected respective pairs of stationary contacts, a load impedance and meter connected in a series circuit to define a common junction, circuit means connecting the outside terminal of the load impedance in said series circuit to one pair of diagonally-connected stationary contacts, a second double-pole, double-throw reversing switch having its poles respectively connected to said common junction and the outside terminal of said meter in said series circuit and having diagonally-connected pairs of stationary contacts, the junction-connected pole being engageable with one of one pair of the last-named diagonallyconnected stationary contacts in one closing position thereof and with one of the other pair oF the last-named diagonally-connected stationary contacts in its opposite closing position, circuit means connecting the ground prong to one pair of diagonallyconnected contacts including said stationary contact of the second double-pole, double-throw switch engageable by the junction-connected pole in said one closing position of said second switch, and circuit means connecting the stationary contact engageable by said junction-connected pole in said opposite closing position to the other pair of diagonallyconnected contacts of the first double-pole, double-throw switch, whereby the system ground wire and the power line ground wire may be individually tested by operating the second double-pole, double-throw switch to apply current drawn by said load impedance to either said system ground wire or said power line ground wire.
Claim 3
Dependent Claim
32 words
The test apparatus of claim 1, and wherein said load impedance is of a value such as to draw a current of approximately 10 amperes when connected to the supply line wires.
Claim 4
Dependent Claim
16 words
The test apparatus of claim 2, an a multiplier resistor connected in series with the meter.
Claim 5
Dependent Claim
15 words
The test apparatus of claim 3, and a shunting switch connected across the multiplier resistor.
Claim 6
Dependent Claim
24 words
The test apparatus of claim 4, and wherein the multiplier resistor has a value of approximately nine times the d.c. resistance of the meter.
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) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |