Patent US4682534A successfully refreshed from Google Patents.
US4682534A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic servo for friction coupling element of automatic transmission
Assignee: Aisin AW Co Ltd
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Filing: 1985-07-29
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Granted: 1987-07-28
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Expires: 2005-07-29
Abstract
Abstract Described herein is a hydraulic servo suitable for friction coupling elements in automatic transmissions. The hydraulic servo of the invention is compact in construction and reduced particularly in axial dimensions, and essentially comprises: an annular drum rotatably or fixedly mounted in a transmission case and having a press-formed annular plate member with an first cylinder portion and a second cylinder member joined to the first cylinder portion by fully encircling welding; a piston fitted between the first cylinder portion and the second cylinder member; and a reaction area formed by extending the annular plate member of the drum radially inward to support return springs.
Inventors
- 👤 Koji Sumiya
- 👤 Takenori Kano
- 👤 Seitoku Kubo
- 👤 Kazuaki Watanabe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:15
CPC Classifications
F; F16; F16H; F16H63/00; F16H63/02; F16H63/30; F16H63/3023; F16H63/3026; Y; Y10; Y10T; Y10T74/00; Y10T74/21; Y10T74/2186
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
134 words
A hydraulic servo for a friction coupling element in an automatic transmission including a casing, said hydraulic servo, comprising: an annular drum having a first cylinder, a second cylinder, and a side wall connecting said first and second cylinders all integrally formed together as a single piece by press forming, said first cylinder having a plurality of splines on its outer cylindrical surface and being fixed to the interior of the casing through said splines and said second cylinder having a plurality of splines on its inner cylindrical surface; a press-formed third cylinder joined to the side wall of said annular drum by a fully encircling weld; a piston fitted between said first cylinder and said third cylinder; and biasing means provided between said third cylinder and said second cylinder for returning said piston.
Claim 2
Dependent Claim
134 words
A hydraulic servo for a friction coupling element in an automatic transmission including a casing, said hydraulic servo, comprising: an annular drum having a first cylinder, a second cylinder, and a side wall connecting said first and second cylinders all integrally formed together as a single piece by press forming, said first cylinder having a plurality of splines on its outer cylindrical surface and being fixed to the interior of the casing through said splines and said second cylinder having a plurality of splines on its inner cylindrical surface; a press-formed third cylinder joined to the side wall of said annular drum by a fully encircling weld; a piston fitted between said first cylinder and said third cylinder; and biasing means provided between said third cylinder and said second cylinder for returning said piston.
Claim 3
Dependent Claim
21 words
The hydraulic servo of claim 1 further comprising a one-way brake having an inner race splined to said inner cylindrical surface.
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) | 1990-07-27 | 1991-01-26 | 1991-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-07-27 | 1995-01-26 | 1995-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-07-27 | 1999-01-26 | 1999-07-28 | $7700.00 | Window Closed / Lapsed |