Patent Application
20090052987
The present invention relates to milling machines that are used in road surface repairs. Milling machines are typically utilized to remove a layer or layers of old or defective road surface in preparation for resurfacing. Resurfacing an existing road surface with such defects may result in a perpetuation of prior existing conditions, especially if the road surface is exposed to heavy and/or continuous traffic which often requires the road to be resurfaced again within a short period of time. Milling may also provide a renewable source of aggregate such as recycled asphalt that may be used to resurface milled surfaces.
Typically the milling machines direct milled road fragments towards a conveyer which takes the fragments off the road, however, a significant amount of debris, aggregate, and fragments remain on the milled surface. When using asphalt or other pavement material to resurface a road the milled surface must be substantially clean of any residue material before a new layer can be deposited. Failure to clear the milled surface of such material may result in poor bonding between the new asphalt and the milled surface. Typically a sweeper will come along after the milling machine to remove of the debris, but often this is inefficient and uneconomic.
U.S. Pat. No. 4,139,318 by Jakob et al., which is herein incorporated by reference for all that it contains, discloses a method and apparatus for planning a paved roadway wherein a main frame is drivingly supported by track assemblies and a planer assembly is disposed in cutting engagement with a top portion of the pave roadway to produce a new roadway surface.
U.S. Pat. No. 4,793,730 by Butch, which is herein incorporated by reference for all that it contains, discloses a method and apparatus for renewing the surface of asphaltic paving at low cost and for immediate reuse.
U.S. Pat. No. 5,505,598 by Murray, which is herein incorporated by reference for all that it contains, discloses a modification of a cold milling machine used to remove concrete and asphalt from an existing highway is disclosed, including a milling drum segmented into two or more sections with the drive train for the milling drums passing through the core of the milling drum and supported via a journal or bearing to the outside of the machine.
U.S. Pat. No. 6,733,086 by McSharry et al., which is herein incorporated by reference for all that it contains, discloses a vacuum system mounted on a portable milling machine for extracting material cut by the milling drum of the machine from the surface of a roadway.
In one aspect of the invention a system for removing a layer of a paved surface comprising a vehicle is adapted to traverse a paved surface in a selected direction. The vehicle has a milling drum with an axle substantially parallel and connected to the vehicle within a milling chamber. The drum is adapted to rotate around the axle between the paved surface and the vehicle. A conveyor belt is attached to a forward end of the vehicle and comprises a portion proximate an opening of the milling chamber. The belt is adapted to carry loose aggregate from the milling drum away from the paved surface. At least one nozzle is disposed on an underside of the vehicle and is in communication with a reservoir through a pathway. The at least one nozzle is adapted to direct the loose aggregate towards the portion of the conveyor belt.
The nozzle may be positioned on the underside of the vehicle near the upper front quadrant of the drum and project fluid at 1,000 to 10,000 PSI toward loose aggregate. The nozzle may also project 10 to 50 gal/min of fluid toward the loose aggregate. The nozzle may be a fluidic nozzle that projects fluid in the direction opposing the rotation of the drum. The nozzle may be pointed in the direction of the conveyor belt. The nozzle may be able to swivel in multiple directions and may be in communication with a power source. The nozzle may also be in communication with a reservoir through a pathway that may comprise fluid, air, gas, water, liquid, carbon dioxide, or a combination thereof The nozzle may extend to at least one pick disposed on the drum and may be adapted to remove loose aggregate. The nozzle may also comprise an arm that extends from the nozzle to the at least one pick on the drum and may be adapted to loosen aggregate disposed on the at least one pick.
The drum within the milling chamber may comprise a fluid, gas, water, liquid, carbon dioxide, or a combination thereof to loosen aggregate on the surface of the drum. The fluid within the drum may also lubricate the pick and surface of the drum. The drum may also comprise at least one hole with which at least one retractable protrusion proceeds in and out of the drum to loosen aggregate on the surface of the drum.
The underside of the vehicle may comprise an arm extending to the pick disposed on the drum and may be adapted to dislodge loose aggregate from the pick. A boundary of the milling chamber may comprise a plurality of picks offset relative to one another. A boundary of the milling chamber may also comprise a brush with the bristles of said brush in contact with the picks disposed on the drum. A boundary of the milling chamber may comprise at least one retractable protrusion adapted to loosen aggregate on the drum. The retractable protrusion may extend to and from the drum.
The vehicle may comprise conveyor belt. The conveyor belt may comprise a vacuum device adapted to remove loose aggregate from the drum and place the loose aggregate onto the conveyor belt.
In another aspect of the invention, a method comprising the steps of providing a vehicle adapted to traverse a paved surface in a selected direction. Providing a milling drum with an axle connected to the vehicle, the drum being adapted to rotate around the axle. Also, providing at least one nozzle in communication with a reservoir through a pathway and being positioned on the underside of the vehicle and near the top left quadrant of the drum opposite the surface. Rotating the drum against a paved surface such that a layer of the paved surface is loosened. Then, cleaning an exposed layer of the paved surface by directing a portion of the loosened aggregate in a generally forward direction by ejecting a fluid out of the at least one nozzle onto the conveyor belt.
A moldboard 210 may be connected to the vehicle 201 which is positioned rearward of the milling drum 203. The moldboard 210 may push loose aggregate or debris along with the milling machine. An end 213 of the moldboard may comprise a leading edge 216 that is adapted to engage the loose aggregate and/or debris. The end 213 may also comprise a rear portion 217 disposed generally rearward the leading edge. In some embodiment, the moldboard may comprises a plurality of nozzles which are adapted to prevent debris, dust, loose aggregate or combinations thereof from escaping underneath the moldboard and direct it back to the milling drum such that the milling drum may direct it to the conveyor belt. Such a system is disclosed in U.S. patent application Ser. No. 11/566,151, which is herein incorporated by reference for all that is contains. Fluid ejected from these nozzles may be carried by fluid line 218 which may connect the nozzles to a fluid reservoir
A plurality of nozzles 212 may be disposed on the underside of the vehicle 201 and proximate the upper front quadrant 251 of the drum 203. The plurality of nozzles 212 may be in communication with a fluid reservoir 214 through a fluid pathway 215. The fluid may comprise hot fluid, air, gas, liquid, carbon dioxide steam, cold fluid, water, polymers, synthetic clay, surfactants, binding agents, or combinations thereof depending on the type of application in which the system 200 is being engaged. In some embodiments the kinetic energy resulting from the fluid being ejected from the nozzles 212 may help to push aggregate towards the conveyor belt 208 and prevent any loose aggregate 209 from traveling over the moldboard. In other embodiments the chemical composition of the fluid may be used to provide a substantially cleaner milled surface 211 for resurfacing. In some embodiments the fluid from the nozzles 212 may also provide a means of substantially reducing dust particles.
Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention.
