US3741406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Friction draft gear
Assignee: Miner Enterprises Inc
•
Filing: 1971-06-22
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Granted: 1973-06-26
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Expires: 1991-06-22
Abstract
Abstract A friction draft gear having a housing closed at one end, resilient means in the housing, and a friction clutch in the open end of the housing which is adapted to provide both a relatively smooth or constant friction action and a highly efficient, substantially square-wave work curve. The friction clutch has a friction bore with an inward taper which may vary from a few degrees to zero degrees, at least one set of friction shoes disposed circumferentially in the friction bore, non-metallic friction material disposed intermediate the friction shoes and the friction bore, and a wedge member engageable with the friction shoes and adapted to receive impact forces.
Inventors
- 👤 D Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:50
CPC Classifications
B; B61; B61G; B61G9/00; B61G9/04; B61G9/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
203 words
In a high-capacity, single action spring-friction draft gear for couplers of railway rolling stock, said draft gear being of the type having a capacity in excess of 36,000 ft. lbs. at a wedge travel of 3 1/4 inches and with a reaction force less than 500,000 lbs., and comprising an elongated hollow metallic housing closed at one end and open at the other end, resilient means within and in contact with the closed end of the housing, a wedge member adjacent the open end of the housing and extending outwardly therefrom and interacting along inclined surfaces with a plurality of radially movable friction members arranged inside of and in engagement with the housing, and means for retaining the draft gear in assembled relationship, the improvement wherein to increase the effectiveness of operation of the draft gear the friction members have a housing-engaging-surface of a friction material having a modulus of elasticity in the range of about 63,000 psi to 133,000 psi and which can withstand up to 40,000 psi in compression and about 7,000 psi in shear whereby the draft gear has impact energy dissipating efficiency in excess of 85 percent and the force-travel curve during impact is substantially of square wave configuration.
Claim 2
Dependent Claim
203 words
In a high-capacity, single action spring-friction draft gear for couplers of railway rolling stock, said draft gear being of the type having a capacity in excess of 36,000 ft. lbs. at a wedge travel of 3 1/4 inches and with a reaction force less than 500,000 lbs., and comprising an elongated hollow metallic housing closed at one end and open at the other end, resilient means within and in contact with the closed end of the housing, a wedge member adjacent the open end of the housing and extending outwardly therefrom and interacting along inclined surfaces with a plurality of radially movable friction members arranged inside of and in engagement with the housing, and means for retaining the draft gear in assembled relationship, the improvement wherein to increase the effectiveness of operation of the draft gear the friction members have a housing-engaging-surface of a friction material having a modulus of elasticity in the range of about 63,000 psi to 133,000 psi and which can withstand up to 40,000 psi in compression and about 7,000 psi in shear whereby the draft gear has impact energy dissipating efficiency in excess of 85 percent and the force-travel curve during impact is substantially of square wave configuration.
Claim 3
Dependent Claim
33 words
A draft gear according to claim 1 wherein the improvement further comprises providing either the inclined surface of the wedge or the corresponding mating surface of the friction member with said friction material.
Claim 4
Dependent Claim
34 words
A draft gear according to claim 1 wherein the improvement further comprises said friction members having surfaces of said friction material engaging both the inclined wedge surface and the inside surface of the housing.
Claim 5
Dependent Claim
21 words
A draft gear according to claim 1 wherein the improvement further comprising said frictIon members consisting solely of said friction material.
Claim 6
Dependent Claim
21 words
A draft gear according to claim 1 wherein the improvement further comprises said friction material including a compressed impregnated asbestos cloth.
Claim 7
Dependent Claim
34 words
A draft gear according to claim 5 wherein the improvement further comprises said asbestos cloth being formed by the dry mold method and including relatively long asbestos fibers and an appreciable amount of copper.
Claim 8
Dependent Claim
26 words
A draft gear according to claim 6 wherein the improvement further comprises said friction material having a dry coefficient of friction of the order of 0.48.
Claim 9
Dependent Claim
19 words
A draft gear according to claim 1 wherein the improvement further comprises said housing having a zero degree taper.
References Cited (Backward Citations)
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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) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |