US3774145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Studio junction box
Assignee: The Association of Motion Picture and Television Producers Inc
•
Filing: 1972-10-19
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Granted: 1973-11-20
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Expires: 1992-10-19
Abstract
Abstract Each junction box assembly comprises a portable stack of rigidly assembled housing units, one for each cable conductor, typically molded of plastic with individual recesses for the respective cable conductors. Internally interconnected bus-bar formations for receiving the presently used connection lugs are mounted deeply within the respective recesses beyond reach of an inserted finger. Side openings too small for insertion of a finger admit an insulated tool for operating the lug clamping screws.
Inventors
- 👤 P Vlahos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:43
CPC Classifications
H; H01; H01R; H01R11/00; H01R11/11; H01R11/26; H01R4/00; H01R4/24
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
264 words
Safety mechanism for releasably interconnecting a plurality of multiple-conductor electrical power cables for temporarily supplying electrical power to portable apparatus on motion picture sets and the like, said cables including a plurality of insulated conductors the end portions of which are separated and carry individual, axially elongated connection lugs which are axially slotted to embrace blade-like bus-bars and which have clamping screws threaded in one lug arm, said mechanism comprising a plurality of flat, stackable housing units of electrically insulative material, each having a plurality of elongated interior coplanar recesses. opening axially to the exterior of said unit, each recess having a transverse section shaped to freely receive an inserted connection lug, and being deep enough to enclose an inserted lug and a portion of the insulated conductor connected thereto, bus-bar structure of electrically conductive material within each housing unit, said structure including a plurality of rigid blades which are integrally interconnected and which project axially into the respective recesses in position to enter the slot of an inserted lug, each blade terminating at least about 3 1/2 inches inwardly of the recess mouth, an aperture through the side wall of each recess and opening to the exterior of said unit in position to admit a tool for operating the screw of an inserted lug to clamp the same to the blade, the aperture having at least one transverse dimension less than about three-eighths inch, and means for assembling the housing units to form a rigid assembly containing a number of units equal to the number of conductors in each cable to be connected.
Claim 2
Dependent Claim
264 words
Safety mechanism for releasably interconnecting a plurality of multiple-conductor electrical power cables for temporarily supplying electrical power to portable apparatus on motion picture sets and the like, said cables including a plurality of insulated conductors the end portions of which are separated and carry individual, axially elongated connection lugs which are axially slotted to embrace blade-like bus-bars and which have clamping screws threaded in one lug arm, said mechanism comprising a plurality of flat, stackable housing units of electrically insulative material, each having a plurality of elongated interior coplanar recesses. opening axially to the exterior of said unit, each recess having a transverse section shaped to freely receive an inserted connection lug, and being deep enough to enclose an inserted lug and a portion of the insulated conductor connected thereto, bus-bar structure of electrically conductive material within each housing unit, said structure including a plurality of rigid blades which are integrally interconnected and which project axially into the respective recesses in position to enter the slot of an inserted lug, each blade terminating at least about 3 1/2 inches inwardly of the recess mouth, an aperture through the side wall of each recess and opening to the exterior of said unit in position to admit a tool for operating the screw of an inserted lug to clamp the same to the blade, the aperture having at least one transverse dimension less than about three-eighths inch, and means for assembling the housing units to form a rigid assembly containing a number of units equal to the number of conductors in each cable to be connected.
Claim 3
Dependent Claim
32 words
Mechanism according to claim 1, and in which each housing unit comprises two like housing elements in face to face engagement, channeled on their opposing faces to form said recesses and apertures.
Claim 4
Dependent Claim
28 words
Mechanism according to claim 1, and in which said bus-bar structure comprises a unitary metal extrusion having a uniform cross section in the plane of the housing unit.
Claim 5
Dependent Claim
56 words
Mechanism according to claim 1, and in which each housing unit is generally rectangular, with two of said recesses opening inwardly on mutually parallel axes from each of two opposite sides of the rectangle, said bus-bar structure comprising a unitary metal extrusion having a uniform cross section of H-form in the plane of the housing unit.
Claim 6
Dependent Claim
43 words
Mechanism according to claim 1, and in which each housing unit is of generally pentagonal form with one of said recesses opening inwardly from each of the sides of the pentagon and generally parallel and closely adjacent a neighboring side of the pentagon.
References Cited (Backward Citations)
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US2924808A
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US3233209A
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US3189860A
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US3315219A
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US3717840A
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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) | 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 |