US3739661A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic transmission system
Assignee: ZF International UK Ltd
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Filing: 1972-03-01
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Granted: 1973-06-19
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Expires: 1992-03-01
Abstract
Abstract A circuit for controlling an automatic transmission system for an engine includes a resistor for supplying a third signal to the input of a summing amplifier, means for supplying a second signal representative of the speed of the vehicle, to the input of the summing amplifier and a transistor for supplying a first signal to the input of the summing amplifier only when the throttle setting of the vehicle exceeds a predetermined value. The arrangement being such that when the second signal exceeds the third signal or the third and first signals together, the circuit will operate to effect a ratio change to reduce the engine speed for a given road speed and vice versa.
Inventors
- 👤 D Harrison
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 07:07
CPC Classifications
B; B60; B60W; B60W30/00; B60W30/18; B60W10/00; B60W10/04; B60W10/06; B60W10/10; B60W2510/00; B60W2510/06; B60W2510/0604; B60W2710/00; B60W2710/10; B60W2710/1005
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
A circuit for controlling the operation of a vehicle automatic transmission system and comprising in combination, means for generating a first signal representative of the throttle setting of the vehicle engine, said means producing said first signal only when the throttle setting is above a predetermined value, means for generating a second signal the magnitude of which is dependent upon the road speed of the vehicle, means for generating a third and fixed signal, means for comparing said signals the arrangement being such that when said second signal exceeds said third signal or said third signal and said first signal the circuit will operate to effect a ratio change to reduce the engine speed for a given road speed and vice versa.
Claim 2
Dependent Claim
122 words
A circuit for controlling the operation of a vehicle automatic transmission system and comprising in combination, means for generating a first signal representative of the throttle setting of the vehicle engine, said means producing said first signal only when the throttle setting is above a predetermined value, means for generating a second signal the magnitude of which is dependent upon the road speed of the vehicle, means for generating a third and fixed signal, means for comparing said signals the arrangement being such that when said second signal exceeds said third signal or said third signal and said first signal the circuit will operate to effect a ratio change to reduce the engine speed for a given road speed and vice versa.
Claim 3
Dependent Claim
64 words
A circuit as claimed in claim 1 in which the means for producing the first signal includes a transistor means for setting the base voltage of said transistor whereby the throttle setting at which said first signal is produced may be set, and means for applying a voltage to the emitter of said transistor, the magnitude of said voltage depending upon the throttle setting.
Claim 4
Dependent Claim
55 words
A circuit as claimed in claim 2 in which said means for comparing said signals comprises a summing amplifier, said first, second and third signals being supplied to the input of the amplifier, and the amplifier switching from one state to another when said second signal exceeds or falls below said first and third signals.
Claim 5
Dependent Claim
36 words
A circuit as claimed in claim 3 including switch means responsive to the condition of the summing amplifier for modifying said first and third signals whereby the road speed at which the amplifier switches will vary.
Claim 6
Dependent Claim
60 words
A circuit as claimed in claim 4 in which said third signal is supplied to the input of the amplifier through a first resistor, the emitter circuit of said transistor including a second resistor, and the base circuit of said transistor including a third resistor, said switch means comprising three transistors switchable to vary the resistances of said resistor respectively.
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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |