US4911679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tensioner for belts
Assignee: Tsubakimoto Chain Co
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Filing: 1989-07-13
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Granted: 1990-03-27
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Expires: 2009-07-13
Abstract
Abstract A hydraulically damped tensioner for a belt transmission system. A piston slidable with clearance in a cylinder form front and rear oil-filled chambers communicating through a passage in the piston with a check valve for restricting flow from the rear chamber to the front chamber. A piston rod is urged through the front chamber and against a roller by a spring in the rear chamber imparting tension on the belt. An opening, sealed by a removable plug, communicate with the front chamber to provide access for filling oil in both chambers.
Inventors
- 👤 Hiroyuki Inoue
- 👤 Yuichi Futami
- 👤 Hiroshi Saisho
- 👤 Kazuharu Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:21
CPC Classifications
F; F16; F16H; F16H7/00; F16H7/08; F16H7/10; F16H7/12; F16H7/1209; F16H7/1236; F16H2007/0802; F16H2007/0806; F16H7/0848; F16H2007/0859; F16H2007/0889; F16H2007/0891
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
60 words
A tensioner for a belt comprising, in combination: a piston rod extending from a piston slidably fitted in a cylinder which is divided by said piston into front and rear chambers filled with oil, said piston rod being biased in a protruding direction by a spring, and port means adjacent to said front chamber for filling said chambers with oil.
Claim 2
Dependent Claim
60 words
A tensioner for a belt comprising, in combination: a piston rod extending from a piston slidably fitted in a cylinder which is divided by said piston into front and rear chambers filled with oil, said piston rod being biased in a protruding direction by a spring, and port means adjacent to said front chamber for filling said chambers with oil.
Claim 3
Dependent Claim
22 words
A tensioner according to claim 1 wherein said port means includes an opening to an oil reservoir communicating with said front chamber.
Claim 4
Dependent Claim
64 words
In a tensioner for a belt drive system including a rod extending from a piston slidable in a cylinder with clearance therebetween, the piston dividing the cylinder into first and second chambers filled with oil and a spring urging the rod through the first chamber against the belt, the improvement comprising: port means communicating with the first chamber for filling said chambers with oil.
Claim 5
Dependent Claim
64 words
In a tensioner for a belt drive system including a rod extending from a piston slidable in a cylinder with clearance therebetween, the piston dividing the cylinder into first and second chambers filled with oil and a spring urging the rod through the first chamber against the belt, the improvement comprising: port means communicating with the first chamber for filling said chambers with oil.
Claim 6
Dependent Claim
39 words
The tensioner improvement according to claim 3 wherein the tensioner further includes an oil reservoir communicating with said front chamber, and wherein said port means further comprises: an opening to said reservoir; and a plug for sealing said opening.
Claim 7
Dependent Claim
90 words
A tensioner for a belt transmission system comprising, in combination: a cylinder closed at each end; a piston slidable in said cylinder with clearance and forming front and rear chambers at either end of said cylinder; a spring urging said piston toward the front chamber; a rod extending from said piston and through said front chamber for imparting tension to the belt; an oil reservoir communicating directly with said front chamber, and including an opening for filling said chambers and reservoir with oil; and a plug for sealing said opening.
Claim 8
Dependent Claim
90 words
A tensioner for a belt transmission system comprising, in combination: a cylinder closed at each end; a piston slidable in said cylinder with clearance and forming front and rear chambers at either end of said cylinder; a spring urging said piston toward the front chamber; a rod extending from said piston and through said front chamber for imparting tension to the belt; an oil reservoir communicating directly with said front chamber, and including an opening for filling said chambers and reservoir with oil; and a plug for sealing said opening.
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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) | 1993-03-26 | 1993-09-25 | 1994-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-26 | 1997-09-25 | 1998-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-26 | 2001-09-25 | 2002-03-27 | $7700.00 | Window Closed / Lapsed |