Patent US3885655A successfully refreshed from Google Patents.
US3885655A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High conductivity lightweight third rail for electric railways
Assignee: Rucker Co
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Filing: 1973-04-27
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Granted: 1975-05-27
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Expires: 1993-04-27
Abstract
Abstract A third rail is provided having the outer cross-sectional configuration of a conventional solid steel third rail but made hollow and composed of aluminum for high conductivity and lightweight with a stainless steel cap for abrasion resistance. Although the third rail is hollow it has sufficient conductivity and current carrying capacity to supply much heavier trains than conventional steel rails. The surface of the rail on which the steel cap is fastened is slotted but the slot is substantially closed by employing the cap to stress the material of the hollow rail to produce a force pressing the steel cap against the adjacent rail surface to achieve low contact resistance.
Inventors
- 👤 James A Corl
- 👤 Ronald J Kilburg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:49
CPC Classifications
B; B60; B60M; B60M1/00; B60M1/30; B60M1/302
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
A composite electrical conductor comprising: a hollow rail made of lightweight electrically conductive material such as aluminum, the rail having a base, two sides integrally formed with the base and an upper wall integrally attached to the sides, the upper wall being formed in two segments which are slightly spaced from each other when the rail is in an unstressed condition; a U-shaped cap formed of an electricaly conductive material such as steel which wears better than aluminum, the cap being dimensioned to fit onto the upper portion of the rail and stress the rail so as to substantially close the gap between the two segments of the rail upper wall and introduce pressure between the cap and the rail to assure good electrical contact between them, the cap and the rail being sufficiently springy such that they remain under stress so as to continue good electrical contact, means forming rounded internal grooves at the junction between the sides and base of the rail which facilitate moving the walls to close the gap when the cap is snapped onto the rail; and means maintaining the cap on the rail in addition to the spring forces of the material.
Claim 2
Dependent Claim
198 words
A composite electrical conductor comprising: a hollow rail made of lightweight electrically conductive material such as aluminum, the rail having a base, two sides integrally formed with the base and an upper wall integrally attached to the sides, the upper wall being formed in two segments which are slightly spaced from each other when the rail is in an unstressed condition; a U-shaped cap formed of an electricaly conductive material such as steel which wears better than aluminum, the cap being dimensioned to fit onto the upper portion of the rail and stress the rail so as to substantially close the gap between the two segments of the rail upper wall and introduce pressure between the cap and the rail to assure good electrical contact between them, the cap and the rail being sufficiently springy such that they remain under stress so as to continue good electrical contact, means forming rounded internal grooves at the junction between the sides and base of the rail which facilitate moving the walls to close the gap when the cap is snapped onto the rail; and means maintaining the cap on the rail in addition to the spring forces of the material.
Claim 3
Dependent Claim
41 words
A conductor bar as described in claim 1 wherein the rail base is approximately 5 inches wide, 4 inches high and has a wall thickness of approximately 3/8 inch carrying a cap having a thickness between approximately 5/32 inch and inch.
Claim 4
Dependent Claim
86 words
A composite electrical conductor bar including: a hollow rail formed with a substantially closed cross-section except for an elongated gap extending lengthwise along the rail; and a cap interference fitting over the portion of the rail having the gap and stressing the rail in the gap closing direction, the cap being formed to conform to the exterior of the rail and being formed of springy material and dimensioned so that it is under spring tension, thereby assuring good electrical contact between the cap and the rail.
Claim 5
Dependent Claim
86 words
A composite electrical conductor bar including: a hollow rail formed with a substantially closed cross-section except for an elongated gap extending lengthwise along the rail; and a cap interference fitting over the portion of the rail having the gap and stressing the rail in the gap closing direction, the cap being formed to conform to the exterior of the rail and being formed of springy material and dimensioned so that it is under spring tension, thereby assuring good electrical contact between the cap and the rail.
Claim 6
Dependent Claim
35 words
The conductor of claim 3 wherein the cap is formed of spring grade steel and the rail is formed of a material, such as aluminum, which is a better electrical conductor than the steel cap.
Claim 7
Dependent Claim
61 words
The conductor of claim 3 wherein the rail has a supporting base, a pair of sides integrally formed with the base and a rail head integrally formed with the sides with said gap being formed in the rail head, and wherein said cap fits over the rail head and onto the rail sides to form a contact surface for the rail.
Claim 8
Dependent Claim
51 words
The conductor of claim 5 wherein the sides of the rail when unstressed toe outwardly with respect to a line perpendicular to the rail base, and the sides of the cap toe inwardly so as to urge the sides of the rail into position perpendicular to the base of the rail.
Claim 9
Dependent Claim
39 words
The conductor of claim 5 wherein the rail head has a slightly convex surface whereby the force acting between the cap and the rail draws the cap against said surface for close physical contact and low electrical contact resistance.
Claim 10
Dependent Claim
51 words
The conductor of claim 5 wherein the sides of the rail are formed with grooves spaced from the rail head and the cap is formed with crimped edges fitting into said grooves, the cap being sufficiently springy such that it can be pre-formed and then pressed directly onto the rail head.
Claim 11
Dependent Claim
30 words
The conductor of claim 5 including fastening means extending through the sides of the cap and into the sides of the rail to further secure the cap to the rail.
Claim 12
Dependent Claim
35 words
The conductor of claim 5 including means at the junctions between the base and the sides which cause the sides to pivot or bend around these junctions when the cap is snapped onto the rail.
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) | 1978-05-26 | 1978-11-25 | 1979-05-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-26 | 1982-11-25 | 1983-05-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-26 | 1986-11-25 | 1987-05-27 | $7700.00 | Window Closed / Lapsed |