US4881927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluidic tensioner
Assignee: Tsubakimoto Chain Co
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Filing: 1989-05-19
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Granted: 1989-11-21
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Expires: 2009-05-19
Abstract
Abstract A hydraulic ball-type check valve tensioner includes a plunger internally provided with an oil chamber and slidably fitted in a housing in association with a spring biasing the plunger in a protruding direction, and a ball-type check valve between the housing and oil chamber to permit oil flows into the oil chamber while blocking oil flow in the reverse direction. A relief valve includes a sleeve slidably fitted in an auxiliary oil chamber in communication with the oil chamber, a spring biasing the sleeve into a depressed position, and a discharge port to be opened when the sleeve is slided against the biasing spring action. A no-return mechanism includes a rack formed on the outer surface of the plunger, and a ratchet rotatably supported in the housing in meshing engagement with the rack and biased by a spring in a direction opposite to the protruding direction.
Inventors
- 👤 Tadasu Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:23
CPC Classifications
F; F16; F16H; F16H7/00; F16H7/08; F16H7/0848; F16H2007/0802; F16H2007/0806; F16H2007/0812; F16H2007/0814; F16H2007/0853; F16H2007/0859; F16H2007/0889; F16H2007/0891
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
118 words
A hydraulic ball-type check valve tensioner including a plunger internally provided with a first fluid chamber and slidably fitted in a housing in association with a first spring biasing said plunger in a protruding direction, a ball-type check valve provided between said housing and said first chamber to permit fluid flow into said first chamber while blocking fluid flow in the reverse direction, characterized in that said tensioner comprises: a relief valve having a sleeve slidably fitted in an auxiliary fluid chamber in communication with said first chamber, a second spring biasing said sleeve into a depressed position, and a discharge port to be opened when said sleeve is slided against the biasing action of said second spring.
Claim 2
Dependent Claim
118 words
A hydraulic ball-type check valve tensioner including a plunger internally provided with a first fluid chamber and slidably fitted in a housing in association with a first spring biasing said plunger in a protruding direction, a ball-type check valve provided between said housing and said first chamber to permit fluid flow into said first chamber while blocking fluid flow in the reverse direction, characterized in that said tensioner comprises: a relief valve having a sleeve slidably fitted in an auxiliary fluid chamber in communication with said first chamber, a second spring biasing said sleeve into a depressed position, and a discharge port to be opened when said sleeve is slided against the biasing action of said second spring.
Claim 3
Dependent Claim
14 words
The tensioner of claim 1, wherein said relief valve is provided in said housing.
Claim 4
Dependent Claim
46 words
The tensioner of claim 2, further comprising: a rack formed on the outer surface of said plunger, and a ratchet rotatably supported on said housing and meshed with said rack, said ratchet being biased by a third spring in a direction opposite to said protruding direction.
Claim 5
Dependent Claim
14 words
The tensioner of claim 1, wherein said relief valve is provided on said plunger.
Claim 6
Dependent Claim
46 words
The tensioner of claim 4, further comprising: a rack formed on the outer surface of said plunger, and a ratchet rotatably supported on said housing and meshed with said rack, said ratchet being biased by a third spring in a direction opposite to said protruding direction.
Claim 7
Dependent Claim
157 words
A fluidic tensioner for a wrapped power transmission device between rotating members, comprising, in combination: a housing having a first fluid-filled chamber therein; a plunger slidably fitted in said first chamber and extending therefrom for bearing against said device to regulate the tension between the rotating members, said plunger having a second fluid-filled chamber therewithin; a first spring biasing said plunger in a protruding direction toward the wrapped power transmission device; a ball-type check valve between said first and second chambers for permitting fluid transfer from said first chamber into said second chamber, and for blocking fluid transfer from said second chamber into said first chamber; and relief valve means having an auxiliary chamber communicating with said first chamber and having a discharge port, a sleeve slidable in said auxiliary chamber for opening and closing said port, and a second spring biasing said sleeve to close said port, for eliminating excessive fluid pressure in said second chamber.
Claim 8
Dependent Claim
157 words
A fluidic tensioner for a wrapped power transmission device between rotating members, comprising, in combination: a housing having a first fluid-filled chamber therein; a plunger slidably fitted in said first chamber and extending therefrom for bearing against said device to regulate the tension between the rotating members, said plunger having a second fluid-filled chamber therewithin; a first spring biasing said plunger in a protruding direction toward the wrapped power transmission device; a ball-type check valve between said first and second chambers for permitting fluid transfer from said first chamber into said second chamber, and for blocking fluid transfer from said second chamber into said first chamber; and relief valve means having an auxiliary chamber communicating with said first chamber and having a discharge port, a sleeve slidable in said auxiliary chamber for opening and closing said port, and a second spring biasing said sleeve to close said port, for eliminating excessive fluid pressure in said second chamber.
Claim 9
Dependent Claim
18 words
A fluidic tensioner according to claim 6, wherein: said relief valve means is integrally formed within said housing.
Claim 10
Dependent Claim
67 words
A fluidic tensioner according to claim 7, further comprising: no-return means having a rack formed on the outer surface of said plunger, a ratchet rotatably supported on said housing for meshing with said rack, and a third spring biasing said ratchet in a direction opposite of said protruding direction, for maintaining tenson in the wrapped power transmission device in the event of a loss of fluid pressure.
Claim 11
Dependent Claim
18 words
A fluidic tensioner according to claim 7, wherein: said relief valve means is integrally formed within said plunger.
Claim 12
Dependent Claim
66 words
A tensioner according to claim 9, further comprising: no-return means having a rack formed on the outer surface of said plunger, a ratchet rotatably supported on said housing for meshing with said rack, and a third spring biasing said ratchet in a direction opposite of said protruding direction, for maintaining tension in the wrapped power transmission device in the event of a loss of fluid pressure.
References Cited (Backward Citations)
JPS49451A
Cited
US3812733A
Cited
GB2065265A
Cited
JPS5951A
Cited
JPS596650A
Cited
US4708696A
Cited
US4708696B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |