BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to slipform paving machines, and more particularly to offset slipform paving machines for forming molded structures having a variable height and variable internal cross-section.

2. Description of the Prior Art

It is known to use relatively large variable height offset molds for paving or forming variable height concrete barriers adjacent a highway. These molds include at least one form insert that is variable in height relative to a mold frame, as well as two side plates to vary the lower portions of the profile of the mold form. These existing machines vary the profile height of the mold form through the use of the lifting columns which support the paving machine.

It is also known to use relatively small offset molds, such as a curb mold, and to provide a curb depressor to reduce the height of the molded curb.

Other types of offset molds may include a mold form which is adjusted in height to adjust a height of a surface of the molded structure. Examples are canal lining molds.

There is a need for improved slipform paving machines designed to improve the use of offset molds wherein a height of at least a portion of the molded structure is varied during the molding operation.

SUMMARY OF THE INVENTION

In one embodiment a slipform paving machine includes a machine frame, and a plurality of ground engaging units for supporting the slipform paving machine from a ground surface. A plurality of height adjustable machine frame supports may support the machine frame from the plurality of ground engaging units. Each of the machine frame supports may include a machine frame support actuator configured to adjust a height of the machine frame relative to a respective one of the ground engaging units. The paving machine further includes an offset mold including a mold frame, a mold form, and a mold form actuator configured to adjust the height of the mold form relative to the mold frame. An external reference sensor may be provided and configured to provide a signal representative of a position of the slipform paving machine relative to an external reference system. A controller may be provided and configured to receive the signal from the external reference sensor, and to control a position of the mold form actuator to control a position of the mold form relative to the mold frame and thereby control a position of at least a portion of the molded structure relative to the ground surface at least in part in response to the signal from the external reference sensor and based at least in part on target values corresponding to a user selected profile for the at least one surface of the molded structure.

The position of the mold form may be a height of the mold form, and the position of the surface of the molded structure may be a height of the surface.

The target values may be stored in the controller as a function of the position of the slipform paving machine relative to the external reference system.

The target values may be stored in the controller as a profile shape to be initiated upon a command input by an operator of the slipform paving machine.

The target values may be generated by the controller as a function of one or more profile parameters of the user selected profile, said profile parameters being input by an operator of the slipform paving machine.

The external reference sensor may include a stringline sensor. The controller may be configured to control extension of the machine frame support actuators to control the height of the mold frame relative to the ground surface at least in part in response to a signal from the stringline sensor.

In any of the above embodiments the controller may be configured to control the position of the mold form actuator at least in part in response to the signal from the stringline sensor.

In any of the above embodiments the external reference sensor may be part of a three-dimensional guidance system. The controller may be configured to control extension of the machine frame support actuators to control the height of the mold frame relative to the ground surface at least in part in response to the signal from the external reference sensor.

In any of the above embodiments the external reference sensor may be part of a three-dimensional guidance system. The controller may be configured to control extension of the mold form actuator to control the height of the mold form relative to the ground surface at least in part in response to the signal from the external reference sensor.

Each of the machine frame supports may include a machine frame support sensor configured to provide a signal corresponding to the height of the machine frame relative to the respective one of the ground engaging units.

In any of the above embodiments the height adjustable machine frame supports may be lifting columns. The machine frame support actuators may include hydraulic piston-cylinder units located within their respective lifting columns, and the machine frame support sensors may be integrated in their respective hydraulic piston-cylinder units.

In any of the above embodiments the slipform paving machine may include a mold form sensor configured to provide a signal corresponding to the position of the mold form relative to the mold frame.

In any of the above embodiments the mold form actuator may be a linear actuator.

In any of the above embodiments the mold form actuator may include a hydraulic piston-cylinder unit, and the mold form sensor may be integrated in the hydraulic piston-cylinder unit of the mold form actuator.

In any of the above embodiments the position of the mold form actuator controlled by the controller may include an extension of the hydraulic piston-cylinder unit.

In any of the above embodiments the controller may be configured to control extension of the machine frame support actuators to control a height of the mold frame relative to the ground surface at least in part in response to a signal from the external reference sensor.

In any of the above embodiments the controller may be configured to control extension of the mold form actuator to control a height of the mold form relative to the ground surface at least in part in response to a signal from the external reference sensor.

In any of the above embodiments the mold form may be configured to form a top surface of the molded structure.

In any of the above embodiments the offset mold may be configured as a curb mold such that the molded structure is a molded curb. The mold form may be configured as a curb depressor so that a height of the molded curb can be reduced at selected locations.

In any of the above embodiments the controller may be further configured to control the mold insert actuator to raise or lower the mold insert as the slipform paving machine moves along a path thus forming a tapered transition of a top surface of the molded structure at least in part in response to the signal from the external reference sensor.

In any of the above embodiments the offset mold may be configured as a ditch or canal lining mold, and the mold form may be configured to form an interior surface of the ditch or canal lining.

In any of the above embodiments the slip form paving machine may further include a mold frame actuator configured to adjust a height of the mold frame relative to the machine frame. A mold frame sensor may be configured to provide a signal corresponding to the height of the mold frame relative to the machine frame. The controller may be further configured to control extension of the machine frame support actuators and the mold frame actuator to control the height of the mold frame relative to the ground surface.

In any of the above embodiments the mold may further comprise first and second side form assemblies. The first side form assembly may include the previously mentioned form insert, form insert actuator and form insert sensor, along with a first side plate and a first side plate actuator configured to adjust a height of the first side plate. The second side form assembly may include a second form insert, a second form insert actuator, a second form insert sensor, a second side plate, and a second side plate actuator configured to adjust the height of the second side plate.

Numerous objects, features and advantages of the present invention will be readily apparent to those skilled in the art upon reading of the following disclosure when taken in conjunction with the accompanying drawings.

