US3786871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grader control
Assignee: Grad Line Inc
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Filing: 1971-07-26
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Granted: 1974-01-22
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Expires: 1991-07-26
Abstract
Abstract A control system for a road grader adapted to maintain the working edge of the grader blade in a preset datum plane so as to establish a uniform graded condition of the surface worked by the blade, regardless of the inclination assumed by the motor grader or the relative angular position of the blade itself. The system includes grade sensor means mounted adjacent one end of the blade to follow a pre-selected grade datum, slope sensing means mounted in fixed relation with the blade for keeping the blade at a predetermined slope with rotary position sensing means mounted on the blade supporting ring or circle to detect the relative angular position of the blade, and longitudinal grade angle sensing means with rotary position sensing means for altering the control signals to compensate for grade changes and rotary position of the blade.
Inventors
- 👤 G Long
- 👤 D Reese
- 👤 F Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:18
CPC Classifications
E; E02; E02F; E02F3/00; E02F3/04; E02F3/76; E02F3/80; E02F3/84; E02F3/844; E02F3/845; Y; Y10; Y10S; Y10S37/00; Y10S37/907
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
329 words
In a traveling machine having a movable frame, a rotatable frame mounted on the movable frame for rotational movement about a rotatable frame axis perpendicular to a plane defined by the rotatable frame, an elongated surface working element secured directly on the rotatable frame for rotational movement about said rotatable frame axis, and adjustment means on the machine to adjust the elevation of one end of the working element relative to the other end and to adjust the rotational position of the working element around the rotatable frame axis relative to the movable frame, said machine being adapted to establish a planar surface having a predetermined cross slope angle defined as the angle between the surface established and a horizontal plane, said angle being located in a vertical plane perpendicular to the direction of travel of the machine, a control system comprising in combination; a slope sensing unit for producing a sensed slope signal indicative of the degree of inclination of said working element relative to a horizontal plane, mounting means for mechanically mounting said slope sensing unit for direct movement with said working element, rotary position sensing means connected between said rotatable frame and said movable frame for producing a rotary position signal indicative of the rotational position of said working element around said rotatable frame axis relative to said movable frame, longitudinal grade sensing means mounted for movement with said movable frame for producing a longitudinal grade signal indicative of the inclination of the longitudinal axis of the movable frame relative to a horizontal plane; and slope control means responsive to said sensed slope signal, said rotary position signal and said longitudinal grade signal to control said adjustment means in a manner to maintain the cross slope angle of the established surface constant, whereby the adjustment means will automatically modify the slope of the wOrking element as the working element is rotated about the rotatable frame axis to maintain constant the cross slope of the established surface.
Claim 2
Dependent Claim
329 words
In a traveling machine having a movable frame, a rotatable frame mounted on the movable frame for rotational movement about a rotatable frame axis perpendicular to a plane defined by the rotatable frame, an elongated surface working element secured directly on the rotatable frame for rotational movement about said rotatable frame axis, and adjustment means on the machine to adjust the elevation of one end of the working element relative to the other end and to adjust the rotational position of the working element around the rotatable frame axis relative to the movable frame, said machine being adapted to establish a planar surface having a predetermined cross slope angle defined as the angle between the surface established and a horizontal plane, said angle being located in a vertical plane perpendicular to the direction of travel of the machine, a control system comprising in combination; a slope sensing unit for producing a sensed slope signal indicative of the degree of inclination of said working element relative to a horizontal plane, mounting means for mechanically mounting said slope sensing unit for direct movement with said working element, rotary position sensing means connected between said rotatable frame and said movable frame for producing a rotary position signal indicative of the rotational position of said working element around said rotatable frame axis relative to said movable frame, longitudinal grade sensing means mounted for movement with said movable frame for producing a longitudinal grade signal indicative of the inclination of the longitudinal axis of the movable frame relative to a horizontal plane; and slope control means responsive to said sensed slope signal, said rotary position signal and said longitudinal grade signal to control said adjustment means in a manner to maintain the cross slope angle of the established surface constant, whereby the adjustment means will automatically modify the slope of the wOrking element as the working element is rotated about the rotatable frame axis to maintain constant the cross slope of the established surface.
Claim 3
Dependent Claim
60 words
The control system according to claim 1 wherein said slope control means includes input slope signal means providing a constant input slope signal of predetermined value corresponding to the desired angle of the working element; and first signal mixing means adapted to produce a first difference signal representing the difference between said input slope signal and said sensed slope signal.
Claim 4
Dependent Claim
51 words
The control system according to claim 1, further including grade sensing and control means connected with said working element and said adjustment means for sensing a preset grade datum and maintaining one end of said working element at a predetermined elevation related to said grade datum during travel of the machine.
Claim 5
Dependent Claim
114 words
The control system according to claim 3, wherein said grade sensing means is adapted to follow said preset grade datum and to provide a grade signal related to deviation of said one end of the working element from the preset datum, input grade signal means providing a constant signal of predetermined value corresponding to the desired elevation of said one end of the working element, grade signal mixing means adapted to produce a difference signal representing the difference between said input grade signal and said sensed grade signal, and grade control means responsive to said difference signal for controlling said adjustment means for correcting the elevation of said one end of the working element.
Claim 6
Dependent Claim
29 words
The control system according to claim 2 wherein said constant input slope signal is modified by said rotary position signal before being supplied to said first signal mixing means.
Claim 7
Dependent Claim
54 words
The control system according to claim 5 including: second rotary position sensing means operatively associated with said working element and responsive to the rotary position of said working element relative to the machine frame for modifying the signal from said longitudinal grade sensing means in relation to the rotary position of said working element.
Claim 8
Dependent Claim
42 words
The control system according to claim 6 including; second signal mixing means connected to receive said difference signal and the modified signal from said longitudinal grade sensing means and adapted to produce a second difference signal for controlling said slope control means.
Claim 9
Dependent Claim
97 words
The control system according to claim 6 wherein; said second rotary position sensing means includes a polarity reversal means operatively associated therewith for reversing the polarity of the signal therefrom so as to be of one polarity when said working element is oriented in one of the two working quadrants of rotation and is of the opposite polarity when said working element is oriented in the other working quadrants of rotation such that correction will result in raising one end of said working element in the first instance and lowering said one end in the second quadrant.
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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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |