US3612017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for automatically controlling vehicle speed
Assignee: Hitachi Ltd
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Filing: 1969-03-25
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Granted: 1971-10-12
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Expires: 1989-03-25
Abstract
Abstract A system for automatically controlling vehicle speed, which is operative in such a manner that a voltage generated by a generator adapted to generate a voltage in proportion to the speed of an automotive vehicle is constantly impressed on the gate electrode of a field-effect transistor and also on the gate electrode of another field-effect transistor and a memory condenser through a normally closed switch, said two field-effect transistors and the respective load resistances forming a bridge circuit, and when automatic control is desired, the potential difference across the potential-detecting terminals of said bridge circuit and its deformation polarity are detected, with said normally closed switch open, whereby an electric motor is controlled for adjusting the degree of opening of the throttle valve of a carburetor.
Inventors
- 👤 Masayuki Ishizaki
- 👤 Koichi Kawatake
- 👤 Ryoji Kasama
- 👤 Masaki Kawai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:03
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; B; B60; B60W; B60W2552/00; B60W2552/15
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
208 words
A system for automatically controlling the running speed of a power-driven vehicle, comprising a power source for driving said vehicle, means for controlling an output of said power source, speed-sensing means for generating an electric signal of a value corresponding to the running speed of the vehicle, comparing means having a first input terminal and a second input terminal for receiving electrical signals from the speed-sensing means and adapted to generate an output corresponding to the magnitude and the sign of the difference between the input electrical signals to both input terminals, a capacitor connected to one of the input terminals of said comparing means for storing the value of said electrical signal, switch means operated by a driver for disconnecting said one of said input terminals having said capacitor connected thereto from said speed-sensing means, operating means for operating said means for controlling the input of the power source for driving the vehicle so as to make the output of said comparing means zero and coupling means for coupling said means for controlling the output of the power source for driving the vehicle with said operating means when the speed-sensing means is disconnected from said one of said input terminals of said comparing means by the driver.
Claim 2
Independent Claim
208 words
A system for automatically controlling the running speed of a power-driven vehicle, comprising a power source for driving said vehicle, means for controlling an output of said power source, speed-sensing means for generating an electric signal of a value corresponding to the running speed of the vehicle, comparing means having a first input terminal and a second input terminal for receiving electrical signals from the speed-sensing means and adapted to generate an output corresponding to the magnitude and the sign of the difference between the input electrical signals to both input terminals, a capacitor connected to one of the input terminals of said comparing means for storing the value of said electrical signal, switch means operated by a driver for disconnecting said one of said input terminals having said capacitor connected thereto from said speed-sensing means, operating means for operating said means for controlling the input of the power source for driving the vehicle so as to make the output of said comparing means zero and coupling means for coupling said means for controlling the output of the power source for driving the vehicle with said operating means when the speed-sensing means is disconnected from said one of said input terminals of said comparing means by the driver.
Claim 3
Dependent Claim
67 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 1, in which said comparing means includes a first field-effect transistor having the gate electrode thereof connected to said capacitor and a second field-effect transistor having the gate electrode thereof connected to said speed-detecting means, and said operating means is operated on the basis of an output differential between said transistors.
Claim 4
Dependent Claim
63 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 2, in which said first and second field-effect transistors in the comparing means each has a resistor connected to the source electrode thereof and a second gate electrode of each field-effect transistor is connected to that terminal of said resistor which is remote from the source electrode.
Claim 5
Dependent Claim
62 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 2, in which said first and second field-effect transistors form a bridge-detecting circuit together with resistors connected to the drain electrodes of said respective transistors and said operating means is operated on the basis of an electrical differential between the detection terminals of said bridge-detecting circuit.
Claim 6
Dependent Claim
48 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 4, including a differential amplifying circuit for converting the potential difference across the detection terminals of said bridge-detecting circuit in the comparing means into two signals corresponding to the differential polarity thereacross.
Claim 7
Dependent Claim
62 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 5, in which said differential amplifying circuit in the comparing means includes a pair of transistors reSpectively having the base electrodes thereof connected to the detection terminals of the bridge-detecting circuit and the emitter electrodes thereof being supplied with a current through a common constant-current circuit.
Claim 8
Dependent Claim
100 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 6, in which said pair of transistors are provided with two resistors respectively connected to the collector electrodes of said respective transistors in series and there are provided another pair of transistors having the emitter-base electrodes thereof connected to the intermediary between the collector electrode of one of said first pair of transistors and one of said resistors and to the intermediary between the collector electrode of the other one of said first pair of transistors and the other one of said resistors respectively.
Claim 9
Dependent Claim
43 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 2, in which a reference potential of the speed-detecting means corresponding to a reference potential of the field-effect transistors in the comparing means is positive in polarity.
Claim 10
Dependent Claim
53 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 8, in which said comparing means and said speed-detecting means are electrically connected with each other in such a manner that the reference potential of the latter becomes slightly higher than the reference potential of the former.
Claim 11
Dependent Claim
71 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 1, in which said speed-detecting means includes a generator connected to a rotary shaft rotating at a rate corresponding to the rotating speed of the vehicle and a voltage generated by said generator is led to an output terminal through an incomplete differentiation circuit consisting of a parallel circuit of a condenser and a resistor.
Claim 12
Dependent Claim
98 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 7, in which between the output terminals is connected a potential dividing circuit including two diodes and a resistor, which are connected with each other in series, the connecting point between said two diodes being connected to the gate electrode of the first field-effect transistor and also to the memory means through a switch which is opened in the state of automatic control, and the outer electrodes of said diodes being connected to the memory means through a normally open switch respectively.
Claim 13
Dependent Claim
84 words
A system for automatically controlling the running speed of a power-driven vehicle as defined in claim 5, in which the power source is an internal combustion engine and the control means for controlling the output of the internal combustion engine includes a throttle valve disposed in an intake manifold including a carburetor and an electric motor for operating said throttle valve, the rotation of said electric motor being reversibly controlled by the two signals obtained from the differential amplifying circuit in the comparing means.
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) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |