US3703298A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for automatic self-levelling of the body of a threshing-harvesting machine
Assignee: Pietro Laverda SpA
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Filing: 1971-06-11
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Granted: 1972-11-21
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Expires: 1991-06-11
Abstract
Abstract Automatic self-levelling of the body of a threshing-harvesting machine is effected by a device which is sensitive to the operation of respective magnetic float switches located in respective interconnected liquid-containing vessels positioned on opposite lateral sides of the body. Each vessel contains two laterally spaced apart float switches connected to electro-valves in an hydraulic circuit for self-levelling actuators so that when either of the laterally outer float switches is operated the actuators are supplied with part of the hydraulic fluid output from a pump to effect correction and when either of the inner switches is operated at a greater angle of inclination, the actuators are supplied with the full pump output to effect rapid levelling. An alarm is operated automatically in the event of excessive inclination of the body of the machine.
Inventors
- 👤 Pietro Laverda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:35
CPC Classifications
A; A01; A01D; A01D75/00; A01D75/28; A01D75/285; B; B60; B60G; B60G2200/00; B60G2200/30; B60G2200/32; B60G2200/322; B60G2300/00; B60G2300/08; B60G2800/00; B60G2800/90; B60G2800/91; B60G2800/912
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
223 words
Device for effecting automatic levelling of the body of a threshing-harvesting machine, comprising in combination: a. two liquid-containing vessels mounted on opposite lateral sides of the body; b. conduit means intercommunicating said vessels; c. first and second magnetic level-sensitive switches in each respective vessel, said two switches being located at different lateral positions in each vessel and being operable selectively in response to lateral inclinations of said body of the machine to the horizontal by more than a first and a second angle respectively, the second angle being greater than the first; d. a double acting fIrst electro-valve operable by the first switches; e. an hydraulic circuit including two hydraulic levelling actuators, said first electro-valve being included in said circuit and controlling supply of hydraulic fluid thereto; f. a pump in said hydraulic circuit; g. a second electro-valve operable by the second switches, said second electro-valve normally reducing the flow of hydraulic fluid under pressure from said pump to the actuators, the latter being supplied with the full pump flow to effect rapid levelling when said second electro-valve is operated by said second switches; h. means operating said two electro-valves manually; i. means sensitive to excessive inclination of said body to the horizontal to prevent said two electro-valves from operating, and, j. an alarm device operable by said means sensitive to excessive inclination.
Claim 2
Dependent Claim
223 words
Device for effecting automatic levelling of the body of a threshing-harvesting machine, comprising in combination: a. two liquid-containing vessels mounted on opposite lateral sides of the body; b. conduit means intercommunicating said vessels; c. first and second magnetic level-sensitive switches in each respective vessel, said two switches being located at different lateral positions in each vessel and being operable selectively in response to lateral inclinations of said body of the machine to the horizontal by more than a first and a second angle respectively, the second angle being greater than the first; d. a double acting fIrst electro-valve operable by the first switches; e. an hydraulic circuit including two hydraulic levelling actuators, said first electro-valve being included in said circuit and controlling supply of hydraulic fluid thereto; f. a pump in said hydraulic circuit; g. a second electro-valve operable by the second switches, said second electro-valve normally reducing the flow of hydraulic fluid under pressure from said pump to the actuators, the latter being supplied with the full pump flow to effect rapid levelling when said second electro-valve is operated by said second switches; h. means operating said two electro-valves manually; i. means sensitive to excessive inclination of said body to the horizontal to prevent said two electro-valves from operating, and, j. an alarm device operable by said means sensitive to excessive inclination.
Claim 3
Dependent Claim
223 words
Device for effecting automatic levelling of the body of a threshing-harvesting machine, comprising in combination: a. two liquid-containing vessels mounted on opposite lateral sides of the body; b. conduit means intercommunicating said vessels; c. first and second magnetic level-sensitive switches in each respective vessel, said two switches being located at different lateral positions in each vessel and being operable selectively in response to lateral inclinations of said body of the machine to the horizontal by more than a first and a second angle respectively, the second angle being greater than the first; d. a double acting fIrst electro-valve operable by the first switches; e. an hydraulic circuit including two hydraulic levelling actuators, said first electro-valve being included in said circuit and controlling supply of hydraulic fluid thereto; f. a pump in said hydraulic circuit; g. a second electro-valve operable by the second switches, said second electro-valve normally reducing the flow of hydraulic fluid under pressure from said pump to the actuators, the latter being supplied with the full pump flow to effect rapid levelling when said second electro-valve is operated by said second switches; h. means operating said two electro-valves manually; i. means sensitive to excessive inclination of said body to the horizontal to prevent said two electro-valves from operating, and, j. an alarm device operable by said means sensitive to excessive inclination.
Claim 4
Dependent Claim
223 words
Device for effecting automatic levelling of the body of a threshing-harvesting machine, comprising in combination: a. two liquid-containing vessels mounted on opposite lateral sides of the body; b. conduit means intercommunicating said vessels; c. first and second magnetic level-sensitive switches in each respective vessel, said two switches being located at different lateral positions in each vessel and being operable selectively in response to lateral inclinations of said body of the machine to the horizontal by more than a first and a second angle respectively, the second angle being greater than the first; d. a double acting fIrst electro-valve operable by the first switches; e. an hydraulic circuit including two hydraulic levelling actuators, said first electro-valve being included in said circuit and controlling supply of hydraulic fluid thereto; f. a pump in said hydraulic circuit; g. a second electro-valve operable by the second switches, said second electro-valve normally reducing the flow of hydraulic fluid under pressure from said pump to the actuators, the latter being supplied with the full pump flow to effect rapid levelling when said second electro-valve is operated by said second switches; h. means operating said two electro-valves manually; i. means sensitive to excessive inclination of said body to the horizontal to prevent said two electro-valves from operating, and, j. an alarm device operable by said means sensitive to excessive inclination.
Claim 5
Dependent Claim
63 words
Device according to claim 1, wherein said manual control means for operating the two electro-valves comprise a lever arranged to act mechanically on the movable part of the first electro-valve and including an electric switch operable simultaneously by said lever to operate said second electro-valve so that the entire output flow of said pump is supplied to said levelling actuators for rapid levelling.
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |