Patent Application
20190186087
The present disclosure relates generally to a road construction machine, and more particularly, to a moldboard support structure for the machine.
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.
Many 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 of asphalt 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 uneconomical. Moreover, it is important for the milling machine to be able to follow and/or track the road surface and its contours being milled while both travelling straight and making curves.
U.S. Pat. No. 7,438,364, issued to Boehme et al. on Oct. 21, 2008 (“the '364 patent”), describes a scraper blade for a milling construction machine to help scrape milled material from behind a milling drum in order to yield a clean milled surface. The scrapper blade includes a blade that trails behind the milling drum, and is adjustable via a piston cylinder unit. The scrapper blade may be secured in a lowered position with a guide in the rear of the milling construction machine. The scraper blade and piston cylinder unit of the '364 patent may not provide sufficient degrees of freedom of movement, and thus, may introduce problematic bending forces on the piston cylinder unit. The moldboard support structure of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem.
In one aspect, a milling machine may include a frame, a ground-engaging rotor assembly, a moldboard, and a hydraulic cylinder including a piston rod and a piston barrel. The ground-engaging rotor assembly may be at least partially enclosed by the moldboard. The moldboard may be vertically moveable via the hydraulic cylinder, and the hydraulic cylinder may be coupled to the frame via a dual-trunnion assembly.
The piston rod may include a coupling portion configured to pivotably couple the piston rod to the moldboard. The milling machine may further include a bearing including a spherical portion, and the spherical portion may mate with the coupling portion of the piston rod. The bearing may further include at least one cylindrical end portion engaging at least one projection of the moldboard. When the piston rod is coupled to the at least one projection, there may be a gap between the coupling portion of the piston rod and the at least one projection such that the coupling portion is pivotable around at least a portion of the spherical portion of the bearing.
The dual-trunnion assembly may include a first cradle mount and a second cradle mount. The second cradle mount may include two cradle pins configured to be received within and pivot relative to the first cradle mount in a first direction, and the piston barrel may include two piston pins configured to be received within and pivot relative to the second cradle mount in a second direction different from the first direction. The first and second cradle mounts may include central openings to allow the piston barrel to extend through and pivot relative to the first and second cradle mounts. The first cradle mount may include a plurality of through holes configured to receive a plurality of fasteners to couple the dual-trunnion assembly to the frame or to the ground-engaging rotor assembly. The dual-trunnion assembly may be coupled to the machine in a central portion of a rear of the machine. The dual-trunnion assembly may be configured to allow for the hydraulic cylinder to pivot in at least two directions based on the position and movement of the moldboard.
The milling machine may further include a safety latch coupled to a bottom portion of the first cradle mount, and the safety latch may be pivotable relative to the first cradle mount. The safety latch may include a hook portion configured to secure a portion of the moldboard when the moldboard is in a raised position.
In another aspect, a milling machine may comprise a milling assembly and a moldboard positioned to the rear of the milling assembly, where a bottom portion of the moldboard includes at least one projection. The milling machine may also include a hydraulic cylinder coupling the moldboard to the milling assembly, and the hydraulic cylinder may be coupled to the moldboard with a spherical portion extending through an end portion of the hydraulic cylinder and through the at least one projection. The hydraulic cylinder may have at least two degrees of freedom of movement relative to the milled assembly.
The milling machine may further comprise a first cradle mount and a second cradle mount, and the hydraulic cylinder may be coupled to the milling assembly via the first cradle mount and the second cradle mount. The first cradle mount may be mounted on a middle portion of the milling assembly. The milling machine may further comprise a safety latch pivotably coupled to the first cradle mount and including a hook portion. The milling machine may also include a handle coupled to the moldboard. The handle may be configured to be securely positioned within the hook portion to secure the moldboard in a raised position.
In yet another aspect, a moldboard mounting assembly may include a hydraulic cylinder, including a piston rod and a piston barrel, where the piston barrel includes two piston pins. The moldboard mounting assembly may also include a first cradle mount and a second cradle mount, where the second cradle mount includes two cradle pins. The second cradle mount may be pivotable in a first direction relative to the first cradle mount, and the piston barrel may be pivotable in a second direction relative to the second cradle mount.
The first cradle mount may be fixedly coupled to a machine. The moldboard mounting assembly may further include a bearing, and a central portion of the bearing may include a spherical portion configured to be received within a mating portion of the piston rod. The moldboard mounting assembly may further include a notched lever extending from and pivotable relative to the first cradle mount.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. As used herein, the terms “comprises,” “comprising,” “having,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus.
For the purpose of this disclosure, the term “ground surface” is broadly used to refer to all types of surfaces that form typical roadways (e.g., asphalt, cement, clay, sand, dirt, etc.) or can be milled in the removal or formation of roadways. In this disclosure, relative terms, such as, for example, “about,” “substantially,” and “approximately” are used to indicate a possible variation of ±10% in a stated value. Although the current disclosure is described with reference to a milling machine, this is only exemplary. In general, the current disclosure can be applied as to any machine, such as, for example, a cold planer, reclaimer, or another milling-type machine.
It is noted that milling assembly 14 may include side doors 26 on each side portion of milling assembly 14. Moldboard 22 and side doors 26 enclose an interior rotor or milling drum assembly (not shown) that engages and mills the ground surface. Each side door 26 may be movably coupled to frame 12 via at least one side hydraulic cylinder 28, for example, in order to raise the side door 26 to inspect or repair milling assembly 14 and/or the internal drum assembly.
Moldboard 22 may help milling assembly 14 to remove the ground surface by removing any loose aggregate or debris that has not been captured by the milling drum assembly. Moldboard 22 may help to push the loose aggregate back toward the milling drum assembly, which may then urge the aggregate to conveyor assembly 16. Removing the loose aggregate may help yield a clean and smooth milled surface behind machine 10, which may then be more easily resurfaced. In order to further urge any loose aggregate toward the milling drum assembly, moldboard 22 may also include an angled interior surface and/or nozzles to dispense fluid. As discussed in greater detail below, moldboard support structure 24 connecting moldboard 22 to machine 10 may help increase the range and degrees of freedom of motion of moldboard 22 to accurately traverse the ground surface, without introducing bending or other strains on moldboard support structure 24.
Moldboard 22 is mounted to a rear portion of machine 10 via moldboard support structure 24. Moldboard support structure 24 includes a rear hydraulic cylinder 30. Rear hydraulic cylinder 30 includes a piston rod 32 movable within and extending out of a piston barrel 34. The movement and position of piston rod 32 relative to piston barrel 34 depends on the movement and pressure of hydraulic fluid, as is known to one having skill in the art. Moldboard support structure 24 also includes a trunnion mount 52 (
As discussed above, rear hydraulic cylinder 30 may be coupled to moldboard 22 via bearing 36, and bearing 36 may be a cylindrical rod. Bearing 36 may allow relative movement between moldboard 22 and rear hydraulic cylinder 30, and may reduce the likelihood of wear on both components. Bearing 36 may couple a bottom portion 44 of moldboard 22 to a piston coupling 46 at a bottom of piston rod 32. Bottom portion 44 of moldboard 22 may include one or more projections 48. Piston coupling 46 and one or more projections 48 may be circular. Piston coupling 46 may be positioned adjacent to one projection 48 or between two projections 48. Bearing 36 may then pass through piston coupling 44 and the one or more projections 48. The coupling may provide for a gap 50 on one or both sides of piston coupling 46 of rear hydraulic cylinder 30. In one aspect, bearing 36 may include a centrally disposed spherical portion 64 (
As noted above, rear hydraulic cylinder 30 may be coupled to machine 10 via a trunnion mount 52. Rear hydraulic cylinder 30 may be “mid-mounted” to machine 10, meaning that rear hydraulic cylinder 30 is coupled to a middle or central portion along the height of machine 10. Piston barrel 34 may be mounted on or positioned substantially even with a top portion of milling assembly 14, and below a user operation position. Trunnion mount 52 may be bolted to a top portion of milling assembly 14 or directly to frame 12. Trunnion mount 52 may be a dual-trunnion mount or double U-joint trunnion mount. As best shown in
As discussed above, trunnion mount 52 includes first cradle mount 54 and second cradle mount 56. Both first cradle mount 54 and second cradle mount 56 each include two cylindrical through holes 66. Cradle pins 58 and piston pins 60 fit through cylindrical through holes 66 of the respective cradle mounts 54, 56 to allow for the two degrees of movement discussed above. Cylindrical through holes 66 may be bushings, which may reduce friction and decrease the necessary maintenance. First cradle mount 54 may also include vertical through holes 68 such that first cradle mount 54 may be fixedly coupled to machine 10 via one or more locking elements or fasteners 70, such as, screws or bolts. It is noted that first cradle mount 54 and second cradle mount 56 may each include a bottom part and a top part, with the two parts being coupled to form cylindrical through holes 66. For example, cradle pins 58 or piston pins 60 may be position on the bottom part, and the top part may be coupled to the bottom part to form cylindrical through holes 66 with cradle pins 58 and piston pins 60 pivotably secured within cylindrical through holes 66. It is further noted that first cradle mount 54 may be connected to milling assembly 14 or frame 12 via an extension piece 71 extending to the rear of milling assembly 14 or frame 12. Extension piece 71 includes a central opening or cutout (not shown) such that rear hydraulic cylinder 30 may move in the first and second directions as discussed above without affecting or contacting milling assembly 14 or frame 12.
Additionally, a safety latch 72 with a vertically facing notched or hook portion 74 may be pivotably coupled to a bottom portion of first cradle mount 54. A first side 76 of first cradle mount 54 may extend away from rear hydraulic cylinder 30 a greater distance than a second side 78 of first cradle mount 54 in order for safety latch 72 to be coupled to a bottom portion of first side 76. Safety latch 72 may extend from either the left or right side of first cradle mount 54 when viewed toward the direction of motion of machine 10. Safety latch 72 may allow a user to lockably position moldboard 22 in a raised position, exposing the interior of milling assembly 14 and the milling drum assembly. For example, as discussed above, moldboard 30 may include handle 42 (
Because moldboard 22 is coupled to machine 10 via rear hydraulic cylinder 30, bearing 36, and trunnion mount 52, moldboard 22 may more closely follow contours of the ground surface, including as machine 10 makes turns. Additionally, if moldboard 22 rotates, twists, or otherwise experiences forces, bearing 36 and trunnion mount 52 help to ensure a stable connection between moldboard 22 and rear hydraulic cylinder 30 without bending, side loading, or otherwise introducing problematic forces on piston rod 32, piston barrel 34, or at the connection of rear hydraulic cylinder 30 to machine 10. As such, machine 10 and moldboard 22 may yield a clean and smooth milled surface after machine 10 passes over the ground surface. Additionally, because rear hydraulic cylinder 30 is mid-mounted to machine 10 as discussed above, a user operating machine 10 may have a clear vertical view of the milled portion of the ground surface.
The disclosed aspects of machine 10 may be used in any milling machine to assist in removal of the milled material, while allowing for variations in milling depth and rotor service. During operation, moldboard 22 may be positioned into the milled cut within the ground surface, and may help to direct the milled material toward the rotor drum and away from machine 10 via conveyor assembly 16. Moldboard 22 may experience torques and other forces as machine 10 traverses and mills the ground surface. The forces on moldboard 22 may be especially strong when machine 10 turns or if the ground surface includes irregularities. Nevertheless, bearing 36 connecting moldboard 22 to piston rod 32 allows for relative movement between the two elements. Moreover, if the movement of moldboard 22 imparts a force on piston rod 32, rear hydraulic cylinder 30 may pivot in at least two directions via trunnion mount 52 as discussed above. Therefore, the aforementioned moldboard mounting assembly assists in reducing forces from being imparted on rear hydraulic cylinder 30, reducing the likelihood of bending moments or other issues affecting rear hydraulic cylinder 30, even as moldboard 22 pivots, translates, and otherwise traverses the ground surface while machine 10 travels to form straight or curved milled cuts. Additionally, the position of rear hydraulic cylinder 30 and its mounting via trunnion mount 52 assists an operator by allowing a clear vertical view to the rear of machine 10 to observe the milled portion of the ground surface that machine 10 has passed over.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed machine without departing from the scope of the disclosure. Other embodiments of the machine will be apparent to those skilled in the art from consideration of the specification and practice of the moldboard support structure disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
