Patent US3705718A successfully refreshed from Google Patents.
US3705718A
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High efficiency leaf spring
Assignee: Aichi Steel Corp
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Filing: 1971-01-05
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Granted: 1972-12-12
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Expires: 1991-01-05
Abstract
Abstract A high efficiency leaf spring which has a circularly arcuate shape in transverse cross section, the radius of curvature of said circularly arcuate shape continuously being increased with the bending moment progressively decreasing from a point where it is largest, based upon a logical analysis and development, so that the maximum tensile stress may be uniform over the entire length of the spring.
Inventors
- 👤 Hiroshi Fukui
- 👤 Gakuji Iwatsu
- 👤 Junichi Kato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:45
CPC Classifications
F; F16; F16F; F16F1/00; F16F1/02; F16F1/18; F16F1/185; B; B60; B60G; B60G2206/00; B60G2206/01; B60G2206/40; B60G2206/42; B60G2206/428; B60G2206/80; B60G2206/81; B60G2206/8109
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
85 words
A leaf spring adapted to be suspended from a vehicle frame at both ends and loaded at the midportion thereof and having a circularly arcuate shape in transverse cross section with its convex side directed upwardly, the radius of curvature of said circularly arcuate shape being continuously increased with the bending moment progressively decreasing towards the ends of the spring from the mid-portion where said bending moment is largest, so that the maximum tensile stress may be uniform over the substantial length of the spring.
Claim 2
Dependent Claim
85 words
A leaf spring adapted to be suspended from a vehicle frame at both ends and loaded at the midportion thereof and having a circularly arcuate shape in transverse cross section with its convex side directed upwardly, the radius of curvature of said circularly arcuate shape being continuously increased with the bending moment progressively decreasing towards the ends of the spring from the mid-portion where said bending moment is largest, so that the maximum tensile stress may be uniform over the substantial length of the spring.
Claim 3
Dependent Claim
77 words
A leaf spring according to claim 1, wherein the angle x of the circularly arcuate shape at each longitudinal point of the leaf spring satisfies the equation wherein Z is the modulus of section corresponding to the varying bending moment M, B is the width of the leaf spring and a is the width to thickness ratio of the leaf spring, and the radius of curvature R of said circularly arcuate shape satisfies the equation B B/x.
Claim 4
Dependent Claim
13 words
A leaf spring according to claim 1, including a second leaf laminated therewith.
References Cited (Backward Citations)
US3452974A
Cited
US3490758A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |