Milling machine control system

Patent metadata

Field	Value
Publication number	US-10865529-B2
Application number	US-202016810249-A
Country	US
Kind code	B2
Filing date	Mar 5, 2020
Priority date	Nov 7, 2017
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

A milling machine includes a primary drum drive assembly for its milling drum, and a ground-engaging drive assembly for driving the milling machine along a roadway. A lifting column is attached between the frame and the ground-engaging drive assembly. The lifting column includes a linear actuator which can raise and lower the frame of the machine with respect to the roadway. A sensor mounted to the lifting column is adapted to determine if the lifting column is not supporting at least a predetermined portion of the weight of the milling machine. A controller is operatively attached to the drive assemblies and to the sensor, and is adapted to receive from the sensor a signal indicating that the lifting column is not supporting the predetermined portion of the weight of the milling machine. Upon receipt of such signal, the controller will automatically control certain machine functions.

First claim

What is claimed is:

1. A milling machine for milling a roadway surface, said milling machine having a milling machine weight and further comprising:
(a) a frame;
(b) a milling assembly comprising:
(i) a drum housing that is attached to the frame;
(ii) a milling drum that is mounted within the drum housing and adapted for rotation about a substantially horizontal axis;

(c) a ground-engaging drive assembly that is operatively attached to a drive control system and is adapted to provide a driving force to drive the milling machine along the roadway surface;
(d) a lifting column that is attached at its upper end to the frame and at its lower end to the ground-engaging drive assembly, said lifting column including:
(i) an outer leg tube which is fixed to the frame and which has a top bracket with an upper surface;
(ii) a linear actuator which can be operated to raise and lower the frame of the machine with respect to the roadway surface;

(e) a load cell sensor that is:
(i) attached to the top bracket of the lifting column in such a manner that it does not rotate or otherwise move with respect to the frame as the lifting column or the ground-engaging drive assembly is operated;
(ii) adapted to determine if the lifting column is not supporting at least a predetermined portion of the weight of the milling machine;
(iii) adapted to generate a signal indicating that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine;

(f) a controller that is:
(i) operatively attached to the drive control system for the ground-engaging drive assembly;
(ii) adapted to control the operation of the drive control system for the ground-engaging drive assembly;
(iii) operatively attached to the load cell sensor;
(iv) adapted to receive the signal indicating that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine;
(v) adapted to cause the drive control system to reduce or stop the driving force provided by the ground-engaging drive assembly when the signal received from the sensor indicates that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine.

2. The milling machine of claim 1 wherein:
(a) the drive control system for the ground-engaging drive assembly comprises a hydraulic motor that is a part of a hydraulic circuit which includes a hydraulic fluid pump;
(b) the controller is adapted to decrease the flow of hydraulic fluid to the hydraulic motor to reduce the driving force provided by the ground-engaging drive assembly when the signal received from the sensor indicates that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine.

3. The milling machine of claim 1 wherein:
(a) the drive control system for the ground-engaging drive assembly comprises a hydraulic motor which is operatively attached to a gearbox with an integrated friction brake;
(b) the controller is adapted to apply the friction brake to reduce the driving force provided by the ground-engaging drive assembly when the signal received from the sensor indicates that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine.

4. The milling machine of claim 1 wherein:
(a) the lifting column includes an inner leg tube having a lower end to which the ground-engaging drive assembly is attached;
(b) the outer leg tube is adapted for axial movement with respect to the inner leg tube;
(c) the linear actuator is attached at its upper end to the outer leg tube and at its lower end to the inner leg tube, and is adapted to move the outer leg tube with respect to the inner leg tube.

5. The milling machine of claim 4 wherein:
(a) the lifting column includes a long axis;
(b) the load cell sensor is mounted to the lifting column in such a manner that it detects only forces that are directed along the long axis of the lifting column.

6. The milling machine of claim 5 wherein the load cell sensor is substantially cylindrical and has an axis that is oriented substantially perpendicular to the long axis of the lifting column.

7. The milling machine of claim 4 wherein the load cell sensor is a pin-type load cell that attaches the upper end of the linear actuator to the outer leg tube.

8. The milling machine of claim 7 wherein the load cell sensor is spaced away from the upper surface of the top bracket.

9. The milling machine of claim 8 wherein:
(a) the top bracket of the outer leg tube has a pair of pin supports, each of which includes a hole;
(b) the upper end of the linear actuator extends through the top bracket of the outer leg tube and includes a hole which is aligned with the holes in the pin supports;
(c) the pin-type load cell is placed through the holes in the pin supports of the top bracket and through the hole in the upper end of the linear actuator in order to attach the linear actuator to the outer leg tube.

10. A milling machine for milling a roadway surface, said milling machine having a milling machine weight and further comprising:
(a) a frame;
(b) a milling assembly comprising:
(i) a drum housing that is attached to the frame;
(ii) a milling drum that is mounted within the milling drum housing and adapted for rotation about a substantially horizontal axis;
(iii) a primary drum drive assembly that is operatively attached to the milling drum and adapted to rotate the milling drum;

(c) a ground-engaging drive assembly that is operatively attached to a drive control system and is adapted to provide a driving force to drive the milling machine along the roadway surface;
(d) a lifting column that is attached at its upper end to the frame and at its lower end to the ground-engaging drive assembly, said lifting column having a long axis and including:
(i) a linear actuator which can be operated to raise and lower the frame of the machine with respect to the roadway surface;
(ii) an outer leg tube which is fixed to the frame and which has a top bracket, said top bracket having an upper surface;

(e) a load cell sensor that is adapted to:
(i) attach the upper end of the linear actuator to the outer leg tube;
(ii) determine if the lifting column is not supporting at least a predetermined portion of the weight of the milling machine;
(iii) generate a signal indicating that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine;

(f) a controller that is:
(i) operatively attached to the drive control system for the ground-engaging drive assembly;
(ii) adapted to control the operation of the drive control system for the ground-engaging drive assembly, including by reducing or stopping the driving force provided by the ground-engaging drive assembly;
(iii) operatively attached to the primary drum drive assembly;
(iv) adapted to control the primary drum drive assembly, including by stopping the rotation of the milling drum;
(v) operatively attached to the load cell sensor;
(vi) adapted to receive the signal indicating that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine;
(vii) adapted, when the signal received from the sensor indicates that the lifting column is not supporting at least the predetermined portion of the weight of the milling machine:
(1) to cause the drive control system to reduce the driving force provided by the ground-engaging drive assembly; or
(2) to cause the drive control system to stop the driving force provided by the ground-engaging drive assembly; or
(3) to cause the primary drum drive assembly to stop t

Assignees

• Roadtec Inc

Inventors

• Avans Todd
• Bevill James H
• Swearingen David

Classifications

• G01G19/12 Primary

  having electrical weight-sensitive devices · CPC title

• E01C23/088 Primary

  Rotary tools, e.g. milling drums {(for forming recesses to receive marking materials E01C23/0946)} · CPC title

• E01C23/127

  rotary, e.g. rotary hammers · CPC title