Patent US3857302A successfully refreshed from Google Patents.
US3857302A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission and speed controlled lock-up clutch
Assignee: Caterpillar Inc
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Filing: 1973-06-25
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Granted: 1974-12-31
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Expires: 1993-06-25
Abstract
Abstract A control valve for a lock-up clutch in a transmission assembly including a torque converter normally coupling a power input member with a transmission speed ratio section, the lock-up clutch being operable to effectively bypass the torque converter, the control valve being differentially responsive to fluid pressure from a speed sensing means to maintain the clutch in either positive engagement or positive disengagement. The control valve is also adapted to provide for both engaged and disengaged operation of the clutch while the transmission speed ratio section is conditioned for operation in a selected speed ratio, the control valve being effective to maintain the clutch in a disengaged condition during relatively lower speed gear settings and to maintain the clutch in an engaged condition during relatively higher speed gear settings, the control valve further providing for disengagement of the clutch during each shift between the speed gear settings.
Inventors
- 👤 H Morris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:10
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/14
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
322 words
A transmission assembly comprising a torque converter for coupling a power input member with a transmission speed ratio section, hydraulically actuated lockup clutch arranged to selectively by-pass the torque converter and effectively couple the input means directly with the transmission speed ratio section, and a control valve assembly for regulating engagement of the clutch, the control valve assembly, including a source of fluid under pressure a control valve for selectively communicating the clutch with the source and with a fluid drain, the control valve including a valve body having a bore, a control spool being movable in the bore to communicate the clutch with the source or drain and resilient means urging the spool toward a position where the clutch is in communication with the drain, speed sensing means providing a fluid signal having a pressure proportional to rotating speed of a member in the transmission assembly, conditioning means operatively communicating the fluid signal to the control valve in response to the transmission speed ratio section having a selected speed gear or relatively higher speed ratio established therein, the control valve being responsive to the fluid signal for effecting both disengagement and engagement of the clutch in the selected speed gear, the control valve being responsive to the fluid signal for maintaining engagement of the clutch in each of the relatively higher speed gears, the conditioning means operatively communicating the fluid signal into the bore to act on one end of the control spool and urge it against the resilient means, and means tending to maintaiN positive engagement or disengagement of the clutch, the means for maintaining positive engagement or disengagement of the clutch comprising a reaction piston slidably arranged in a bore of effectively reduced diameter at the other end of the control spool to form a reaction chamber therein and means for selectively communicating the chamber with the fluid signal from the speed sensing means and with a fluid drain.
Claim 2
Dependent Claim
322 words
A transmission assembly comprising a torque converter for coupling a power input member with a transmission speed ratio section, hydraulically actuated lockup clutch arranged to selectively by-pass the torque converter and effectively couple the input means directly with the transmission speed ratio section, and a control valve assembly for regulating engagement of the clutch, the control valve assembly, including a source of fluid under pressure a control valve for selectively communicating the clutch with the source and with a fluid drain, the control valve including a valve body having a bore, a control spool being movable in the bore to communicate the clutch with the source or drain and resilient means urging the spool toward a position where the clutch is in communication with the drain, speed sensing means providing a fluid signal having a pressure proportional to rotating speed of a member in the transmission assembly, conditioning means operatively communicating the fluid signal to the control valve in response to the transmission speed ratio section having a selected speed gear or relatively higher speed ratio established therein, the control valve being responsive to the fluid signal for effecting both disengagement and engagement of the clutch in the selected speed gear, the control valve being responsive to the fluid signal for maintaining engagement of the clutch in each of the relatively higher speed gears, the conditioning means operatively communicating the fluid signal into the bore to act on one end of the control spool and urge it against the resilient means, and means tending to maintaiN positive engagement or disengagement of the clutch, the means for maintaining positive engagement or disengagement of the clutch comprising a reaction piston slidably arranged in a bore of effectively reduced diameter at the other end of the control spool to form a reaction chamber therein and means for selectively communicating the chamber with the fluid signal from the speed sensing means and with a fluid drain.
Claim 3
Dependent Claim
54 words
The transmission assembly of claim 1 wherein the transmission speed ratio section comprises a plurality of clutches and a speed ratio valve means for selectively engaging the clutches to establish the speed gears, the conditioning means being responsive to the speed ratio valve means for disengaging the clutch during each shift between speed gears.
Claim 4
Dependent Claim
55 words
The transmission assembly of claim 2 wherein the transmission speed ratio section also provides a speed gear relatively lower than the selected speed gear, the speed sensing means providing a fluid signal which is ineffective to operate the conditioning means during operation with the relatively lower speed gear established in the transmission speed ratio section.
Claim 5
Dependent Claim
64 words
The transmission assembly of claim 1 wherein the conditioning means comprises a resiliently positioned conditioning spool arranged in axial alignment with the one end of the control spool, the conditioning spool being responsive to fluid pressure established by the transmission speed ratio section for directing the fluid signal from the speed sensing means to effectively act against the one end of the control speed.
Claim 6
Dependent Claim
23 words
The transmission assembly of claim 1 further comprising means defining a restrictive orifice for communicating the reaction chamber with the speed sensing means.
Claim 7
Dependent Claim
256 words
In a transmission assembly including a torque converter for coupling a power input member with a transmission speed ratio section, a hydraulically actuated lock-up clutch arranged to selectively bypass the torque converter and effectively couple the input member directly with the transmission speed ratio section and a speed sensing means providing a fluid signal having a pressure proportional to rotating speed of a member in the transmission assembly, a control valve assembly for positively regulating engagement and disengagement of the clutch, the control valve assembly comprising a source of fluid under pressure, and a control valve communicating the clutch with the source and with a fluid drain, the control valve being responsive to the fluid signal from the speed sensing means for effecting both disengagement and engagement of the clutch, the control valve having a valve body defining a bore wherein a control spool is movable to selectively communicate the clutch with the source and the fluid drain, resilient means urging the spool toward a position for communicating the clutch with the drain, the spool including means having a relatively large effective surface communicated with the fluid signal whereupon the control spool is urged against the resilient means toward a position for communicating the clutch with the fluid source, the control spool also including means having a relatively smaller effective surface in communication with a reaction chamber, the reaction chamber being in selective communication with the fluid signal from the speed sensing means and a fluid drain during movement of the control spool in its bore.
Claim 8
Dependent Claim
256 words
In a transmission assembly including a torque converter for coupling a power input member with a transmission speed ratio section, a hydraulically actuated lock-up clutch arranged to selectively bypass the torque converter and effectively couple the input member directly with the transmission speed ratio section and a speed sensing means providing a fluid signal having a pressure proportional to rotating speed of a member in the transmission assembly, a control valve assembly for positively regulating engagement and disengagement of the clutch, the control valve assembly comprising a source of fluid under pressure, and a control valve communicating the clutch with the source and with a fluid drain, the control valve being responsive to the fluid signal from the speed sensing means for effecting both disengagement and engagement of the clutch, the control valve having a valve body defining a bore wherein a control spool is movable to selectively communicate the clutch with the source and the fluid drain, resilient means urging the spool toward a position for communicating the clutch with the drain, the spool including means having a relatively large effective surface communicated with the fluid signal whereupon the control spool is urged against the resilient means toward a position for communicating the clutch with the fluid source, the control spool also including means having a relatively smaller effective surface in communication with a reaction chamber, the reaction chamber being in selective communication with the fluid signal from the speed sensing means and a fluid drain during movement of the control spool in its bore.
Claim 9
Dependent Claim
23 words
The transmission assembly of claim 6 further comprising means defining a restrictive orifice for communicating the reaction chamber with the speed sensing means.
Claim 10
Dependent Claim
69 words
The transmission assembly of claim 6 further comprising conditioning means operatively communicating the fluid signal to effectively act against the one end of the control spool in response to the transmission speed ratio section having a selected speed gear of relatively higher speed gear established therein, the control spool being responsive to the fluid signal for maintaining engagement of the clutch in each of the relatively higher speed gears.
Claim 11
Dependent Claim
53 words
The transmIssion assembly of claim 8 wherein the transmission speed ratio section comprises a plurality of clutches and speed ratio valve means for selectively engaging the clutches to establish the speed gears, the conditioning means being responsive to the speed ratio valve means for disengaging the clutch during each shift between speed gears.
Claim 12
Dependent Claim
54 words
The transmission assembly of claim 6 wherein the transmission speed ratio section comprises a plurality of clutches which are selectively and hydraulically engaged to establish the speed ratios, the control spool being operatively responsive to hydraulic engagement of the clutches for communicating the clutch with the fluid drain during each shift between speed ratios.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |