Patent US3794947A successfully refreshed from Google Patents.
US3794947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Line protector for a communication circuit
Assignee: Reliable Electric Co
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Filing: 1971-10-06
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Granted: 1974-02-26
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Expires: 1991-10-06
Abstract
Abstract A plug-in line protector for a communications circuit provides protection for over voltage and over current conditions of the line. A cup and slug module containing carbon blocks provides an air gap for grounding high voltage transients. For an over current condition, a solder pellet melts causing the cup and slug to engage due to spring pressure and ground the line through a grounding strip. The grounding strip has plastic insulation bonded to a portion thereof and interposed between the line and ground. In an over current condition heat from one of the carbon blocks is transferred through the cup to the metalic strip. This heat may cause the plastic to melt to provide a back-up or secondary low resistance path to ground. The protector may also have a resettable over current responsive mechanism in the form of a heat coil in the line. When the heat coil breaks, a printed circuit board, on which the heat coil is mounted, is moved by a volute spring. In over voltage and in over current conditions, the volute spring conducts current from the printed circuit board to the slug and cup and to ground.
Inventors
- 👤 B Baumbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:42
CPC Classifications
H; H01; H01H; H01H71/00; H01H71/10; H01H71/12; H01H71/14; H01H71/20; H01H71/205; H01T; H01T1/00; H01T1/14
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
254 words
In a line protector for communications circuitry, said protector having a base of insulating material, first and second conductive terminals mounted on said base, means forming a conductive connection between said first and second terminals to provide a line circuit through said protector, a conductive ground terminal, and a shunt circuit for over voltage and over cuRrent fault conditions in said line circuit; said shunt circuit including normally spaced apart contact members, one of said contact members being in conductive connection with said ground terminal, spaced blocks defining an air gap, spring means urging said contact members toward their engaged positions, and a solder element that normally maintains said contact members apart in opposition to said spring means, whereby an over voltage of short duration at either of said first or second terminals produces an arc at said air gap and current flow therethrough to said ground terminal, and an over voltage of longer duration causes the solder element to melt and causes said spring means to urge said contact members into engagement to provide a current path to said ground terminal; a grounding strip conductively connected to said ground terminal and to one of the contact members and forming part of said shunt circuit, and an insulating strip interposed between said line circuit and said grounding strip for melting upon heating due to an over current condition in the line circuit to provide an auxiliary, low resistance, short current path from said line circuit through said grounding strip and to said ground terminal.
Claim 2
Dependent Claim
254 words
In a line protector for communications circuitry, said protector having a base of insulating material, first and second conductive terminals mounted on said base, means forming a conductive connection between said first and second terminals to provide a line circuit through said protector, a conductive ground terminal, and a shunt circuit for over voltage and over cuRrent fault conditions in said line circuit; said shunt circuit including normally spaced apart contact members, one of said contact members being in conductive connection with said ground terminal, spaced blocks defining an air gap, spring means urging said contact members toward their engaged positions, and a solder element that normally maintains said contact members apart in opposition to said spring means, whereby an over voltage of short duration at either of said first or second terminals produces an arc at said air gap and current flow therethrough to said ground terminal, and an over voltage of longer duration causes the solder element to melt and causes said spring means to urge said contact members into engagement to provide a current path to said ground terminal; a grounding strip conductively connected to said ground terminal and to one of the contact members and forming part of said shunt circuit, and an insulating strip interposed between said line circuit and said grounding strip for melting upon heating due to an over current condition in the line circuit to provide an auxiliary, low resistance, short current path from said line circuit through said grounding strip and to said ground terminal.
Claim 3
Dependent Claim
17 words
In a line protector according to claim 1, said insulating strip being bonded to said grounding strip.
Claim 4
Dependent Claim
18 words
In a line protector according to claim 2, said one contact member being seated on said grounding strip.
Claim 5
Dependent Claim
42 words
In a line protector according to claim 1, said one contact member being a cup-shaped piece that contains one of said spaced blocks such that heating of said one spaced block in turn heats said contact member in said over current condition.
Claim 6
Dependent Claim
56 words
In a line protector according to claim 1, said one contact member being a cup and the other contact member being a slug, an insulating sleeve surrounding said cup and slug, and said spaced blocks and solder element being within said insulating sleeve, the slug being movable in said sleeve upon melting of said solder element.
Claim 7
Dependent Claim
23 words
In a line protector according to claim 1, said grounding strip being a generally T-shaped piece with the insulating strip being bonded thereto.
Claim 8
Dependent Claim
27 words
In a line protector according to claim 1, said spring means being a contact constituting said means forming the conductive connection between said first and second terminals.
Claim 9
Dependent Claim
14 words
In a line protector according to claim 1 said spring being a volute spring.
Claim 10
Dependent Claim
60 words
In a line protector according to claim 8, said means forming a conductive connection between said first and second terminals including aboard having printed circuits thereon and a heat responsive mechanism operable to break said conductive connection of said line circuit in an over current condition thereof, said volute spring engaging said printed circuit and imposing force on said board.
Claim 11
Dependent Claim
176 words
In a line protector for communication circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means also including another shunt circuit that includes blocks defining an air gap, contact members in conductive connection with said blocks, spring means urging said contact members together, and a solder element maintaining said contact members apart in opposition to said spring means, one of said contact members housing one of said blocks and engaging said grounding strip so that heat from said one block may be transmitted through said one contact to said insulating strip.
Claim 12
Dependent Claim
176 words
In a line protector for communication circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means also including another shunt circuit that includes blocks defining an air gap, contact members in conductive connection with said blocks, spring means urging said contact members together, and a solder element maintaining said contact members apart in opposition to said spring means, one of said contact members housing one of said blocks and engaging said grounding strip so that heat from said one block may be transmitted through said one contact to said insulating strip.
Claim 13
Dependent Claim
61 words
In a line protector according to claim 10 said spring means Including a volute spring, said protector also including a circuit board of insulating material with printed circuits thereon, said printed circuits being in said line circuit, and said volute spring being in said other shunt circuit and engaging said board and being in conductive connection with a printed circuit thereon.
Claim 14
Dependent Claim
32 words
In a line protector according to claim 10, said spring means comprising a metallic portion forming said conductive means, said spring means having opposed end portions with said contact members confined therebetween.
Claim 15
Dependent Claim
155 words
In a line protector for communications circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means adjacent to said strip also includes a spring-pressed member in another shunt circuit from said line circuit to said ground terminal for urging said grounding strip into electrical contact with said conductive means that connects said line terminals to provide a low resistance short current path from the line circuit to said ground terminal.
Claim 16
Dependent Claim
155 words
In a line protector for communications circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means adjacent to said strip also includes a spring-pressed member in another shunt circuit from said line circuit to said ground terminal for urging said grounding strip into electrical contact with said conductive means that connects said line terminals to provide a low resistance short current path from the line circuit to said ground terminal.
Claim 17
Dependent Claim
137 words
In a line protector for a communications circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means adjacent to said strip also including a component in another shunt circuit from said line circuit to said ground terminal and responsive to an over current fault in said line for heating said insulating strip.
Claim 18
Dependent Claim
137 words
In a line protector for a communications circuitry, said protector having a line circuit with terminals and conductive means connecting said line terminals, a ground terminal, and a shunt circuit from said line circuit to said ground terminal and responsive to an over current fault at either of said circuit terminals, said shunt circuit including a grounding strip and an insulating strip laminated thereto, said insulating strip normally interrupting said shunt circuit, and means adjacent to said insulating strip and responsive to an over current condition in said line circuit for melting said insulation strip and closing said shunt circuit; said means adjacent to said strip also including a component in another shunt circuit from said line circuit to said ground terminal and responsive to an over current fault in said line for heating said insulating strip.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |