Paving apparatus with automatic mold positioning control system
First Claim
1. A self-propelled construction apparatus for continuously slip-forming paving material into a predetermined cross-sectional shape on a ground surface having an external datum, comprising:
- a frame;
a plurality of ground engaging members including a steerable ground engaging member and at least one driven ground engaging member;
a plurality of posts adjustably supporting said frame on said plurality of ground engaging members for propulsion and steering of said frame thereby, each post of said plurality of posts being extendable and retractable to adjust the position of said frame relative to said ground engaging members;
a slip form mold attached to said frame for depositing and forming paving material onto the ground surface during propulsion of said frame thereover, said slip form mold defining a predetermined reference point and a cross slope transversely relative to the direction of propulsion of said frame, said slip form mold being attached to said frame such that changing the position of said frame also changes the position of said slip form mold;
a paving material distribution system positioned on said frame to continuously distribute paving material to said slip form mold;
a plurality of sensors attached to said frame for detecting changes in the position of said frame relative to the external datum and for generating output signals proportional to the detected changes, each said sensor defining a null point corresponding to a predetermined position of said frame relative to the external datum; and
an automatic control system for receiving input signals from said plurality of sensors and for generating output signals for controlling extension and retraction of said plurality of posts and said steerable ground engaging member to control the position of said slip form mold relative to the external datum, said control system being adapted to maintain a substantially constant relative position between the predetermined reference point on said slip form mold and the external datum while changing the cross slope of said slip form mold during propulsion of said frame by altering the null point of at least one sensor of said plurality of sensors.
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Accused Products
Abstract
An apparatus and method for automatically controlling operation of a slip form paver to maintain a substantially constant mold position relative to a string line while changing the cross slope of the mold. The paver follows a path over the ground relative to a string line using grade and steer sensors to detect changes in the vertical and horizontal distance of the mold relative to the string line. A slope sensor detects changes in cross slope of the mold. Piston-cylinder mechanisms responsive to signals from the steer, slope and grade sensors as used to position the mold relative to the string line. During changes in the cross slope of the mold as the paver travels, the control system periodically alters the null point of the steer sensor to offset for horizontal changes in mold position relative to the string line caused by changing the mold cross slope and periodically alters the null point of the grade sensors to offset for vertical changes in mold position relative to the string line caused by changing the mold cross slope. The magnitude of steer sensor offset is determined the vertical distance between the string line and a predetermined reference point on the mold and by the detected cross slope. The magnitude of grade sensor offset is determined by the horizontal distance between the string line and a predetermined reference point on the mold and by the detected cross slope.
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Citations
17 Claims
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1. A self-propelled construction apparatus for continuously slip-forming paving material into a predetermined cross-sectional shape on a ground surface having an external datum, comprising:
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a frame; a plurality of ground engaging members including a steerable ground engaging member and at least one driven ground engaging member; a plurality of posts adjustably supporting said frame on said plurality of ground engaging members for propulsion and steering of said frame thereby, each post of said plurality of posts being extendable and retractable to adjust the position of said frame relative to said ground engaging members; a slip form mold attached to said frame for depositing and forming paving material onto the ground surface during propulsion of said frame thereover, said slip form mold defining a predetermined reference point and a cross slope transversely relative to the direction of propulsion of said frame, said slip form mold being attached to said frame such that changing the position of said frame also changes the position of said slip form mold; a paving material distribution system positioned on said frame to continuously distribute paving material to said slip form mold; a plurality of sensors attached to said frame for detecting changes in the position of said frame relative to the external datum and for generating output signals proportional to the detected changes, each said sensor defining a null point corresponding to a predetermined position of said frame relative to the external datum; and an automatic control system for receiving input signals from said plurality of sensors and for generating output signals for controlling extension and retraction of said plurality of posts and said steerable ground engaging member to control the position of said slip form mold relative to the external datum, said control system being adapted to maintain a substantially constant relative position between the predetermined reference point on said slip form mold and the external datum while changing the cross slope of said slip form mold during propulsion of said frame by altering the null point of at least one sensor of said plurality of sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An automatic control system for changing the cross slope of a mold on a self-propelled paving apparatus from an initial cross slope to a predetermined altered cross slope as the paving apparatus travels over a ground surface in a desired path relative to the external datum, comprising:
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at least one grade sensor adapted and positioned to continuously detect deviations in the vertical distance of the predetermined reference point on the mold relative to the external datum and to generate an output signal proportional to the detected deviation, said grade sensor defining a null point corresponding to a predetermined position of the paving apparatus relative to the external datum; a steer sensor adapted and positioned to continuously detect deviations in the horizontal distance of the predetermined reference point on the mold relative to the external datum and to generate an output signal proportional to the detected deviation, said steer sensor defining a null point corresponding to a predetermined position of the paving apparatus relative to the external datum; a slope sensor adapted and positioned to continuously detect deviations in the cross slope of the mold as the paving apparatus travels over the ground surface and to generate an output signal proportional to the detected deviation in cross slope, said slope sensor defining a null point corresponding to a predetermined position of the paving apparatus relative to the external datum; and a processor for receiving input signals from said at least one grade, steer, and slope sensors and for generating output signals for steering the paving apparatus and for changing the elevation and cross slope of the mold relative to the external datum, said processor periodically receiving an input from said slope sensor corresponding to the altered cross slope of the mold, determining the change in relative horizontal and vertical distance between the predetermined reference point on the mold and the external datum caused by changing cross slope of the mold from the initial cross slope to the predetermined altered cross slope, altering the null point of said steer sensor an amount corresponding to the determined change in relative horizontal distance caused by changing cross slope of the mold, and altering the null point of said at least one grade sensor an amount corresponding to the determined change in vertical distance caused by changing the cross slope of the mold, thereby maintaining a substantially constant relative position between the predetermined reference point on the mold and the external datum during changes in the cross slope of the mold as the paving apparatus travels over the ground surface. - View Dependent Claims (11, 12, 13)
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14. A method of operating a self-propelled paving apparatus having a paving mold and traveling over a ground surface relative to an external datum using a steer sensor to detect deviations in a horizontal distance between a predetermined reference point on the mold and the external datum and at least one grade sensor to detect deviations in a vertical distance between the predetermined reference point on the mold and the external datum, the steer sensor and at least one grade sensor each defining a null point corresponding to a predetermined position of the mold relative to the external datum, while changing a cross slope of the mold from an initial cross slope to an altered cross slope as the paving apparatus travels over the ground surface, said method comprising the steps of:
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continuously detecting the cross slope of the mold as the paving apparatus travels over the ground surface; periodically determining a change in the horizontal distance between the predetermined reference point on the mold and the external datum caused by changing the mold cross slope from the initial cross slope to the altered cross slope; periodically determining a change in the vertical distance between the predetermined reference point on the mold and the external datum caused by changing the mold cross slope from the initial cross slope to the altered cross slope; altering the null point of the at least one grade sensor an amount corresponding to and offsetting the determined change in vertical distance between the predetermined reference point on the mold and the external datum caused by changing the mold cross slope from the initial cross slope to the altered cross slope; and altering the null point of the steer sensor an amount corresponding to and offsetting the determined change in horizontal distance between the predetermined reference point on the mold and the external datum caused by changing the mold cross slope from the initial cross slope to the altered cross slope, thereby maintaining a substantially constant relative position between the predetermined reference point on the mold and the external datum while changing the cross slope of the mold as the paving apparatus travels along a desired path relative to the external datum. - View Dependent Claims (15, 16, 17)
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Specification