US3732755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital shift control for vehicular transmission
Assignee: ZF Friedrichshafen AG
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Filing: 1971-03-18
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Granted: 1973-05-15
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Expires: 1991-03-18
Abstract
Abstract To change the speed ratio of an automatically shiftable power train by which the torque of an engine is transmitted to the traction wheels of a vehicle, a logic circuit emits commands to respective solenoid valves in response to a combination of operating parameters such as vehicle speed, engine temperature, accelerator position and road gradient. Speed is measured by a pulse generator, coupled with the output shaft of the transmission, whose pulses are counted by an accumulator that is periodically reset by a timing circuit and whose count between resettings is fed to the logic circuit together with signals indicating the position of a manual speed selector. The remaining parameters are used to modify the rhythm of the timer or the operation of a decoder inserted between the accumulator and the logic circuit.
Inventors
- 👤 W Beig
- 👤 W Kuhnle
- 👤 H Seibold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:09
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/02; F16H61/0202; F16H61/0204; F16H61/0206; F16H59/00; F16H59/60; F16H59/66; F16H61/0213; Y; Y10; Y10S; Y10S477/00; Y10S477/90; Y10S477/901; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219; Y10T74/19251; Y10T74/19256; Y10T74/1926; Y10T74/19377; Y10T74/19414; Y10T74/19419; Y10T74/19423; Y10T74/19428; Y10T74/19437
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
197 words
In an automotive vehicle having an engine, a driven shaft, a transmission of variable speed ratio coupling said engine to said driven shaft, fuel-control means for said engine and shift means for varying said speed ratio, the combination therewith of: electric pulse-generating means coupled with said driven shaft for emitting a train of rate pulses at a cadence proportional to the speed of said shaft; sensing means responsive to an operating parameter affecting the optimum operating point of said shift means; signal-generating means controlled by said sensing means to produce an output related to said operating parameter; a processor having an input stage connected to said signalgenerating means; accumulator means in said processor coupled to said pulsegenerating means for counting said rate pulses; timing means in said processor connected to said accumulator means for resetting same at the end of a recurrent counting period; actuating means for said shift means controlled by said processor in response to a predetermined count of said rate pulses indicative of shaft speed; and modifying circuitry in said timing means responsive to said output for altering the duration of said counting period, thereby varying the shaft speed corresponding to said predetermined count.
Claim 2
Dependent Claim
197 words
In an automotive vehicle having an engine, a driven shaft, a transmission of variable speed ratio coupling said engine to said driven shaft, fuel-control means for said engine and shift means for varying said speed ratio, the combination therewith of: electric pulse-generating means coupled with said driven shaft for emitting a train of rate pulses at a cadence proportional to the speed of said shaft; sensing means responsive to an operating parameter affecting the optimum operating point of said shift means; signal-generating means controlled by said sensing means to produce an output related to said operating parameter; a processor having an input stage connected to said signalgenerating means; accumulator means in said processor coupled to said pulsegenerating means for counting said rate pulses; timing means in said processor connected to said accumulator means for resetting same at the end of a recurrent counting period; actuating means for said shift means controlled by said processor in response to a predetermined count of said rate pulses indicative of shaft speed; and modifying circuitry in said timing means responsive to said output for altering the duration of said counting period, thereby varying the shaft speed corresponding to said predetermined count.
Claim 3
Dependent Claim
90 words
The combination defined in claim 1 wherein said timing means comprises a first clock controlled by said modifying circuitry for generating a succession of framing cycles of variable length, defining said counting period, and a second clock measuring a series of invariable gating intervals substantially longer than said framing cycles, said processor including a second accumulator for registering the number of framing cycles per gating interval, said actuating means being jointly controlled by said accumulators to operate said shift means at an instant codetermined by said count and said number.
Claim 4
Dependent Claim
42 words
The combination defined in claim 2 wherein said timing means comprises a source of clock pulses and frequency-dividing means connected to said source for deriving from said clock pulses a succession of lower-cadence framing pulses of a length defining said counting period.
Claim 5
Dependent Claim
22 words
The combination defined in claim 4 wherein said modifying circuitry is connected to said frequency-dividing means for varying the step-down ratio thereof.
Claim 6
Dependent Claim
45 words
The combination defined in claim 1, further comprising a manual speed-ratio selector with a plurality of operating positioNs and circuit means extending from said selector to said processor for blocking the response of said actuating means to said count in certain of said operating positions.
Claim 7
Dependent Claim
25 words
The combination defined in claim 1 wherein said pulse-generating means comprises a ferromagnetic pinwheel on said driven shaft and inductive pickup means adjacent said pinwheel.
Claim 8
Dependent Claim
14 words
The combination defined in claim 1 wherein said modifying circuitry comprises a logic network.
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) | 1976-05-14 | 1976-11-13 | 1977-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-14 | 1980-11-13 | 1981-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-14 | 1984-11-13 | 1985-05-15 | $7700.00 | Window Closed / Lapsed |