Patent US3741036A successfully refreshed from Google Patents.
US3741036A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vehicle transmission control systems
Assignee: CAV Ltd
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Filing: 1971-01-27
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Granted: 1973-06-26
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Expires: 1991-01-27
Abstract
Abstract A vehicle transmission control system including a plurality of solenoids each of which when energized causes engagement of a particular forward gear ratio of a vehicle gear box, a manually operable selector switch whereby a particular solenoid can be energized and a plurality of switches in series with one or more of the solenoids respectively. Means in the form of transistor and a generator is provided to control the operation of the switches respectively whereby energization of each solenoid can only occur if the road speed of the vehicle is below a predetermined value.
Inventors
- 👤 R Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:44
CPC Classifications
F; F16; F16H; F16H61/00; F16H61/16
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
100 words
A control circuit for a vehicle transmission system having a plurality of selectable gear ratios and a plurality of solenoids for effecting engagement of said ratios respectively, said control circuit comprising a manually operable selector switching means operable to cause energization of said solenoids in turn, said control circuit also comprising a switch circuit in series with at least one of said solenoids and means responsive to the road speed of the vehicle to control the operation of said switch whereby energization of said solenoid can occur only if the road speed of the vehicle is below a predetermined value.
Claim 2
Dependent Claim
100 words
A control circuit for a vehicle transmission system having a plurality of selectable gear ratios and a plurality of solenoids for effecting engagement of said ratios respectively, said control circuit comprising a manually operable selector switching means operable to cause energization of said solenoids in turn, said control circuit also comprising a switch circuit in series with at least one of said solenoids and means responsive to the road speed of the vehicle to control the operation of said switch whereby energization of said solenoid can occur only if the road speed of the vehicle is below a predetermined value.
Claim 3
Dependent Claim
95 words
A circuit as claimed in claim 1 in which said switch circuit comprises: a normally open pair of contacts; a relay coil for operating said contacts, a transistor having the relay coil connected in its collector emitter path, and means for supplying a voltage to the base of the transistor, said voltage being variable in accordance with the road speed of the vehicle, said voltage having a magnitude to prevent conduction of the transistor in the event that the vehicle speed is above the safe speed at which the particular gear ratio can be selected.
Claim 4
Dependent Claim
28 words
A circuit as claimed in claim 2 in which said relay coil is connected in circuit with the selector switching means when the particular gear ratio is selected.
Claim 5
Dependent Claim
52 words
A circuit as claimed in claim 3 including a further pair of normally open contacts in parallel with said transistor said normally open pair of contacts being closed by the relay with which the transistor is associated, said further pair of normally open contacts constItuting a holding circuit for the associated relay.
Claim 6
Dependent Claim
78 words
A circuit as claimed in claim 4 in which a further transistor, relay coil, a normally open pair of relay contacts and a further pair of normally open pairs of relay contacts are provided to control another of said solenoids, the circuit also including pairs of normally closed contacts associated with the relays respectively, each pair of normally closed contacts serving to maintain the previous solenoid energized in the event that energization of a selected solenoid is prevented.
Claim 7
Dependent Claim
64 words
A circuit as claimed in claim 2 in which the means for supplying a voltage to the base of the transistor comprises a generator the output voltage of which varies in accordance with the road speed at which the vehicle is driven, and a resistance network associated with the transistor so that the conduction of the transistor will be prevented at an appropriate speed.
Claim 8
Dependent Claim
72 words
A circuit as claimed in claim 5 including a further transistor and a further relay, the coil of the further relay being connected in the collector emitter path of the further transistor, said further transistor being energized when the vehicle is at rest and when the selector switch is in one or more selected positions, said further relay including a pair of normally closed contacts through which current flows to the solenoids.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |