This invention relates to grading machines and more particularly to an attachment for a wheeled vehicle having a moldboard that may be positioned selectively for backsloping, frontsloping and tailgrading operations, and transporting the moldboard when not in use.
One type of conventional grading machine consists of a rigid frame mounted on a pair of wheel units, an engine and operator's cab mounted on the frame just forward of a rear wheel unit and a grader moldboard mounted on the underside of the frame between the operator's cab and a front wheel unit. Typically, the grader moldboard may be angled and adjusted vertically to provide various grading operations on level terrain such as a roadway, a runway and the like. For grading on sloping terrain, it has been the practice to provide a slope grading attachment for such machines which generally consists of a moldboard having an inner end thereof connected to a rear end of the machine with the moldboard projecting laterally and downwardly of the machine, and a pull bar interconnecting an outer free end of the sloper moldboard and either a forward portion of the machine frame or an outer end portion of the grader moldboard. An example of such type of machine and sloping attachment is disclosed in U.S. Pat. No. 2,847,772 to Wayne W. McMullen.
In a modification of the type of grader machine described, there is provided an articulated frame including a rear frame section mounted on a rear wheel unit and supporting an engine and the operator's cab, a front frame section mounted on a front wheel unit and supporting a depending grader moldboard. Sloping attachments mounted on such articulated machines typically consist of a moldboard connected at an inner end to the rear frame section of the machine, and a pull bar interconnecting an outer free end of the sloper moldboard and either the front frame section of the machine or an outer end portion of the grader moldboard.
Such types of machines, however, have several disadvantages. Because of the manner of use of pull bars, the sloper moldboard cannot be positioned for tailgrading or backsloping. If the pull bar is connected at or adjacent the free end of the sloper moldboard, it is difficult if not impossible to position the free end of the sloper moldboard close to standing objects such as telephone poles, road signs, guard rail posts and the like or under guard rails to perform slope grading. Where the pull bar is connected to the grader moldboard, it is not possible to simultaneously perform level grading and slope grading operations unless the fixed angular relationship of the grader and sloper moldboards is suitable for the task being performed or the length of the pull bar is adjustable. Furthermore, where the machine is of the articulated type, it is not possible to perform simultaneous level grading and slope grading operations without locking out the articulated front end section of the machine.
More recently, there has been developed in the prior art a sloping attachment of the type described in which the conventional pull bar interconnecting the sloper and grader moldboards is eliminated and an outer portion of the sloper moldboard is connected through an extensible link to a support frame of the sloper attachment. In such type of arrangement, the orientation of the sloper moldboard may be adjusted independent of the grader moldboard. An example of such type of attachment is disclosed in U.S. Pat. No. 3,049,822 to Wayne W. McMullen. In such type of sloper attachment, however, it has been found that the sloper moldboard cannot be maneuvered sufficiently to position it effectively in backsloping, frontsloping, tailgrading and transporting positions, and further to orient the sloper moldboard in each of such positions to provide a desired operating or storage attitude of the sloper moldboard. Such prior art type of attachment further has been found to be deficient in that it does not adequately provide for positioning the sloper moldboard sufficiently laterally of the vehicle during backsloping and frontsloping operations to permit the vehicle to traverse on level terrain such as a roadway, or provide for positioning the sloper moldboard sufficiently adjacent the wheeled vehicle to provide a compact arrangement of the sloper attachment when the attachment is not in use and is being transported along a roadway or otherwise.
Accordingly, it is the principal object of the present invention to provide an improved ground working attachment for a wheeled vehicle.
Another object of the present invention is to provide an improved attachment for a wheeled vehicle operable to provide slope grading functions.
A further object of the present invention is to provide an improved attachment for a wheeled vehicle capable of performing level and slope grading functions.
A still further object of the present invention is to provide an improved attachment for a wheeled vehicle which is operable to provide backsloping, frontsloping and tailgrading functions.
Another object of the present invention is to provide a sloper attachment for a conventional grader machine.
A further object of the present invention is to provide an improved sloper attachment for a grader machine provided with a grader moldboard in which a sloper moldboard of the attachment may be adjusted and operated independently of the grader moldboard.
A still further object of the present invention is to provide an improved attachment for a wheeled vehicle capable of performing backsloping, frontsloping and tailgrading operations in which the vehicle may be driven on level terrain such as a roadway during a sloping operation.
Another object of the present invention is to provide an improved attachment for a wheeled vehicle capable of performing backsloping, frontsloping and tailgrading operations in which a sloping blade thereof may be positioned sufficiently adjacent a side of the vehicle to provide a compact arrangement of the attachment to facilitate the transportation of the attachment when not in use and being transported from one site to another.
A still further object of the present invention is to provide a sloper attachment mountable on a conventional grader machine which can be readily detached from the machine by removing a set of connecting pins and disconnecting several hydraulic lines equipped with quick disconnect fittings.
Another object of the present invention is to provide an improved sloper attachment for a grader machine which can be positioned in cooperation with a grader moldboard to spread material dozed by take grader moldboard, in a single pass of the machine thus increasing the productivity of the machine.
A further object of the invention is to provide an improved sloper attachment for an articulated grader machine which can be positioned in a tailgrading position and cooperate with the grader moldboard of the machine in a sideshifted position to provide a wide grading swath corresponding to the combined lengths of the cooperating grader and sloper moldboards.
Another object of the invention is to provide an improved sloper attachment for a conventional grader machine which is capable of performing slope grading operations close to standing objects such as telephone poles, road signs, guard rail posts and culverts and under guard rails and the like.
A further object of the present invention is to provide an improved combination sloping and grading attachment for a wheeled vehicle which is relatively simple in design, comparatively easy to manufacture and easy to operate.
Other objects and advantages of the present invention will become more apparent to those persons having ordinary skill in the art to which the present invention pertains from the following description taken in conjunction with the accompanying drawings in which: