Patent US3888035A successfully refreshed from Google Patents.
Patent US3876013A successfully refreshed from Google Patents.
US3876013A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-leveling rotary screw grader
Assignee: Individual
•
Filing: 1972-11-16
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Granted: 1975-04-08
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Expires: 1992-11-16
Abstract
Abstract An earth moving and leveling grader capable of being hitched to and pulled by a self-propelled vehicle such as a tractor, includes a rigid frame that mounts a rotary screw conveyor at its forward section and a roller at its rearward section. The rotary screw conveyor is operatively connected to a tractor power takeoff shaft. The rigid frame is detachably coupled to the tractor by a force transmitting framework connected to a depth cutting adjustment means. When the depth cutting adjustment means is actuated then resulting deformation or reshaping of the force transmitting framework causes the roller to serve as a fulcrum in order to selectively urge the rotary screw to a shallower or deeper cutting depth. When a new cutting depth is attained then the roller, due to its connection with the rotary screw conveyor through the rigid frame and force transmitting framework, will tend to maintain the rotary screw conveyer on the desired cutting level even when it encounters earth depressions and other terrain irregularities.
Inventors
- 👤 Charles William Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:00
CPC Classifications
E; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/78; E02F3/783; A; A01; A01B; A01B31/00; A01B33/00; A01B33/02; A01B33/021; A01B33/022
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
288 words
A self-leveling rotary screw grader capable of being drawn by a vehicle, the grader comprising: a. a rigid frame having a longitudinal axis; b. a rotary screw secured to a front section of the rigid frame and having an axis generally perpendicular to the rigid frame longitudinal axis; c. depth cutting adjustment means coupled to the rigid frame for selectively controlling the cutting depth of the rotary screw; d. a roller secured to a rearward section of the rigid frame behind the rotary screw, the roller being structurally arranged to serve as a fulcrum for urging the rotary screw to a new cutting level when the depth cutting adjustment means is actuated and to thereafter serve as a level maintaining follower when the new cutting level is attained; e. a force transmitting framework coupled to the depth cutting adjustment means and arranged to interconnect the rigid frame with a vehicle, the force transmitting framework being arranged to experience deformation upon actuation of the depth control adjustment means to cause the roller to serve as a fulcrum for the rotary screw; f. power means for operating the rotary screw and causing it to convey earth laterally to one side of the rigid frame, the power means including a vehicle power take-off shaft operatively coupled to the rotary screw for rotating it in a direction opposite from the rotational direction of the roller; g. a scraper blade pivotally connected to a rearward section of the rigid frame, the scraper blade being movable to a position spanning a rearward section of the roller for scraping earth from the roller; and, h. tilt adjusting means coupled to the force transmitting framework for selectively tilting the rigid frame sideways about its longitudinal axis.
Claim 2
Dependent Claim
288 words
A self-leveling rotary screw grader capable of being drawn by a vehicle, the grader comprising: a. a rigid frame having a longitudinal axis; b. a rotary screw secured to a front section of the rigid frame and having an axis generally perpendicular to the rigid frame longitudinal axis; c. depth cutting adjustment means coupled to the rigid frame for selectively controlling the cutting depth of the rotary screw; d. a roller secured to a rearward section of the rigid frame behind the rotary screw, the roller being structurally arranged to serve as a fulcrum for urging the rotary screw to a new cutting level when the depth cutting adjustment means is actuated and to thereafter serve as a level maintaining follower when the new cutting level is attained; e. a force transmitting framework coupled to the depth cutting adjustment means and arranged to interconnect the rigid frame with a vehicle, the force transmitting framework being arranged to experience deformation upon actuation of the depth control adjustment means to cause the roller to serve as a fulcrum for the rotary screw; f. power means for operating the rotary screw and causing it to convey earth laterally to one side of the rigid frame, the power means including a vehicle power take-off shaft operatively coupled to the rotary screw for rotating it in a direction opposite from the rotational direction of the roller; g. a scraper blade pivotally connected to a rearward section of the rigid frame, the scraper blade being movable to a position spanning a rearward section of the roller for scraping earth from the roller; and, h. tilt adjusting means coupled to the force transmitting framework for selectively tilting the rigid frame sideways about its longitudinal axis.
Claim 3
Dependent Claim
111 words
The structure according to claim 1, wherein; the force transmitting framework includes a variable length bar coupled to the depth cutting adjustment means in such a manner that the variable-length bar may be selectively shortened or lengthened by the depth cutting adjustment means to vary the cutting level of the rotary screw; and, the depth cutting adjustment means includes a double acting fluid cylinder incorporated within the variable length bar and arranged such that when the ram is extended from the cylinder the rotary screw is moved to a shallow cutting depth and when its ram is retracted into the cylinder the rotary screw is moved to a deeper cutting depth.
Claim 4
Dependent Claim
159 words
The structure according to claim 1, wherein: the rigid frame includes a pair of laterally spaced and forwardly extending bars; and, the force transmitting framework includes; first and second upwardly converging diagonal bars pivoted by their lower ends to corresponding rigid frame bars to constitute first and second pin joints, a third bar pivoted at one end to the rigid frame and to both the first and second bars at its other end to constitute a third pin joint, the third bar being a variable length bar coupled to the depth cutting adjustment means, three hitch arms extending forwardly from the first, second and third pin joints respectively for connection to a vehicle, wherein when the variable-length bar is lengthened the three pin joints become raised to urge the rotary screw to a shallower cutting depth and when the variable-length bar is shortened the three pin joints become lowered to urge the rotary screw to a deeper cutting depth.
Claim 5
Dependent Claim
57 words
The structure according to claim 3, wherein the rigid frame includes: a hood enclosing a top and rearward portion of the rotary screw, the hood having a lower rearward portion that mounts a leveling blade whose lower edge can be adjustably positioned to be in the same horizontal plane as the bottom flight of the rotary screw.
Claim 6
Dependent Claim
43 words
The structure according to claim 4, wherein: a cutting bar is secured to and extends rearwardly from the scraper blade so that when the frame is pushed in a reverse direction the scraper blade and cutting bar operate as an earth moving surface.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |