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US4798563A Expired / Lapsed US ⏱️ 0.0 years remaining

Self-contained type automatic belt tensioner

Assignee: Toyota Motor Corp
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Filing: 1987-12-08
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Granted: 1989-01-17
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Expires: 2007-12-08
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Abstract

Abstract A self-contained type automatic belt tensioner adjusts a tension of an engine timing belt for automobiles. The tensioner comprises a body, a plunger slidably mounted in the body, a reservoir chamber located in the plunger, a pressure chamber disposed between the plunger and a closed wall of the body, a rod member fixed to the plunger, a bellows shaped elastic diaphragm located in the reservoir chamber with one end thereof being fixed to the rod member and the other end being fixed to the body, a check valve allowing a fluid flow only from the reservoir chamber to the pressure chamber, and a return spring interposed between the plunger and the closed wall of the body so as to bias said plunger in the direction of the rod member.

Inventors

  • 👤 Yoshio Okabe
  • 👤 Yukimori Kobayashi
  • 👤 Makoto Ishikawa
  • 👤 Tamotsu Kamiya
  • 👤 Tomiaki Atsumi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 12:27
CPC Classifications
F; F16; F16H; F16H7/00; F16H7/08; F16H7/10; F16H7/12; F16H7/1209; F16H7/1236; F16H7/1254; F16H7/1281; F16H2007/0802; F16H2007/0812; F16H7/0848; F16H2007/0859

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 184 words
A self-contained type automatic belt tensioner for automobiles comprising: a body having an axially extending blind bore therein with an opening at one end, a closed wall at the other end; a plunger slidably mounted in said blind bore of said body; a reservoir chamber located in said plunger; a pressure chamber disposed between said plunger and said closed wall of said body; a rod member fixed at one end thereof to said plunger and protruding at the other end thereof from said opening of said body; a bellows shaped elastic diaphragm located in said reservoir chamber with one end thereof being fixed to said rod member and the other end being fixed to said body; a fluid passage connecting said reservoir chamber and said pressure chamber with each other; a check valve disposed in said fluid passage so as to allow a fluid flow only from said reservoir chamber to said pressure chamber; and a return spring interposed between said plunger and said closed wall of said body so as to bias said plunger in the direction of said opening of said body.
Claim 2
Dependent Claim 184 words
A self-contained type automatic belt tensioner for automobiles comprising: a body having an axially extending blind bore therein with an opening at one end, a closed wall at the other end; a plunger slidably mounted in said blind bore of said body; a reservoir chamber located in said plunger; a pressure chamber disposed between said plunger and said closed wall of said body; a rod member fixed at one end thereof to said plunger and protruding at the other end thereof from said opening of said body; a bellows shaped elastic diaphragm located in said reservoir chamber with one end thereof being fixed to said rod member and the other end being fixed to said body; a fluid passage connecting said reservoir chamber and said pressure chamber with each other; a check valve disposed in said fluid passage so as to allow a fluid flow only from said reservoir chamber to said pressure chamber; and a return spring interposed between said plunger and said closed wall of said body so as to bias said plunger in the direction of said opening of said body.
Claim 3
Dependent Claim 43 words
A self-contained type automatic belt tensioner according to claim 1, wherein said one end of said diaphragm is fixed to said rod member through a seal member and said other end of said diaphragm is fixed to said body through a seal member.
Claim 4
Dependent Claim 28 words
A self-contained type automatic belt tensioner according to claim 2, wherein said both ends of said diaphragm are prevented from moving by means of a stopper member, respectively.
Claim 5
Dependent Claim 32 words
A self-contained type automatic belt tensioner according to claim 1, wherein a stopper member is secured to said body to prevent said plunger from moving in the direction of said reservoir chamber.
Claim 6
Dependent Claim 20 words
A self-contained type automatic belt tensioner according to claim 1, wherein a fluid passage is formed in said rod member.
Claim 7
Dependent Claim 33 words
A self-contained type automatic belt tensioner according to claim 1, wherein a rotation stopper member is fixed at both ends thereof to said body so as to prevent said rod member from rotating.
Claim 8
Dependent Claim 25 words
A self-contained type automatic belt tensioner according to claim 1, wherein said check valve comprises a ball member and a spring supported by a retainer.

References Cited (Backward Citations)

JPS59126144A Cited
US4539001A Cited
US4674996A 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) 1992-01-17 1992-07-18 1993-01-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-01-17 1996-07-18 1997-01-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-01-17 2000-07-18 2001-01-17 $7700.00 Window Closed / Lapsed

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