US3834503A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual hydraulic coupling
Assignee: ZF Friedrichshafen AG
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Filing: 1973-04-02
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Granted: 1974-09-10
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Expires: 1993-04-02
Abstract
Abstract A dual hydraulic clutch, mounted on a shaft for operatively connecting same with either of two pinions seated thereon, has a central partition flanked by two axially movable pistons adapted to co-operate with respective sets of clutch plates. An axial displacement of either piston entrains two interconnected rings on opposite sides of the partition, each ring carrying a pair of spring-loaded plungers normally bearing on the partition for biasing both pistons into a retracted position. Upon the admission of pressure fluid to a piston for the engagement of its clutch plates, the corresponding plungers unblock a pair of normally blocked ports in the partition for the circulation of lubricant to the respective clutch assembly.
Inventors
- 👤 G Maurer
- 👤 F Geiger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:47
CPC Classifications
F; F16; F16D; F16D25/00; F16D25/10; F16D25/06; F16D25/062; F16D25/063; F16D25/0635; F16D25/0638
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
152 words
A dual hydraulic coupling comprising: a central structure forming a pair of oppositely facing hydraulic cylinders; a pair of pistons in said cylinders; a pair of transmission elements on opposite sides of said structure; a pair of associated coupling assemblies respectively interposed between said pistons and said transmission elements for operatively connecting the latter with said structure, said pistons being hydraulically shiftable into respective working positions for actuating the associated coupling assemblies; a carriage slidably guided in said structure for entrainment by either of said pistons upon displacement thereof into its working position, said carriage being provided with resilient means normally bearing upon said structure for biasing said pistons into a retracted position; a source of ancillary fluid for said assemblies; and valve means controlled by said biasing means for establishing a flow path from source through either of said assemblies upon displacement of the associated piston into said working position thereof.
Claim 2
Dependent Claim
152 words
A dual hydraulic coupling comprising: a central structure forming a pair of oppositely facing hydraulic cylinders; a pair of pistons in said cylinders; a pair of transmission elements on opposite sides of said structure; a pair of associated coupling assemblies respectively interposed between said pistons and said transmission elements for operatively connecting the latter with said structure, said pistons being hydraulically shiftable into respective working positions for actuating the associated coupling assemblies; a carriage slidably guided in said structure for entrainment by either of said pistons upon displacement thereof into its working position, said carriage being provided with resilient means normally bearing upon said structure for biasing said pistons into a retracted position; a source of ancillary fluid for said assemblies; and valve means controlled by said biasing means for establishing a flow path from source through either of said assemblies upon displacement of the associated piston into said working position thereof.
Claim 3
Dependent Claim
44 words
A coupling as defined in claim 1 wherein said structure comprises a shaft and an annular partition rigid with said shaft, said pistons and assemblies being annular and coaxially mounted on said shaft, said carriage being an annular cage centered on the shaft axis.
Claim 4
Dependent Claim
23 words
A coupling as defined in claim 2 wherein said transmission elements are pinions carried on said shaft on opposite sides of said partition.
Claim 5
Dependent Claim
17 words
A coupling as defined in claim 2 wherein said source includes a supply conduit in said shaft.
Claim 6
Dependent Claim
39 words
A coupling as defined in claim 4 wherein said shaft is part of a power train driven by an engine, said source further including a pump driven by said engine and working into said conduit with a speed-depending pressure.
Claim 7
Dependent Claim
78 words
A coupling as defined in claim 4 wherein said cage comprises a pair of end rings each provided with at least two spring-loaded plungers normally bearing upon said partition at peripherally spaced points, said valve means including a pair of entrance ports and a pair of exit ports in said partition obstructed by said plungers in the retracted position of the associated pistons, said entrance ports communicating with said supply conduit, said exit ports opening into respective drains.
Claim 8
Dependent Claim
75 words
A coupling as defined in claim 6 wherein said shaft is provided with two channels alternately connectable to the high-pressure side and the low-pressure side of a circulation system for hydraulic fluid, each of said channels communicating with a respective cylinder for operatively displacing the associated piston upon being connected to said high-pressure side, the drain of each exit port opening into the channel communicating with the cylinder on the opposite sIde of said partition.
Claim 9
Dependent Claim
40 words
A coupling as defined in claim 6 wherein said cage comprises a set of threaded rods connected with said end rings and spacer tubes surrounding said rods between said end rings, said spacer tubes being slidably mounted in said partition.
Claim 10
Dependent Claim
40 words
A coupling as defined in claim 6 wherein said cage comprises a set of threaded rods connected with said end rings and spacer tubes surrounding said rods between said end rings, said spacer tubes being slidably mounted in said partition.
Claim 11
Dependent Claim
19 words
A coupling as defined in claim 4 wherein said supply conduit passes through said shaft along the axis thereof.
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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |