Patent Application
20130206432
The present invention relates to motor graders, and, more particularly, to blade positioning linkages used with such motor graders.
A motor grader is used to rough or finish grade an earth surface and includes a base unit with a main frame supporting traction wheels, operator cab, engine compartment, transmission, and a belly mounted (moldboard) blade. The blade extends downwardly from a circle drive arrangement which adjusts the angular orientation of the blade relative to a generally vertical axis. The circle drive arrangement is movably connected with the main frame at the front end. A blade positioning linkage attached to the main frame interconnects with the rear of the circle drive arrangement via a pair of blade positioning cylinders.
When using a motor grader it is important to have as much visibility as possible to and around the front axle and tires, as well as the blade. A blade positioning linkage having deficiencies in visibility to and around the front axle and tires causes the operator to lean or adjust his position in the seat to gain the visibility needed to perform certain tasks. It is also important to see out over the main frame to be able to see objects in the machines path. Visibility is impaired with a blade positioning linkage that wraps completely around the main frame.
Conventional blade positioning linkages typically either use a 4-bar type linkage with sculpted arms to hold the blade positioning cylinders or use a single sculpted piece that is attached to and completely wraps around the main frame. Examples of blade positioning linkages are disclosed in U.S. Pat. No. 4,696,350 (Ruhter et al.) and U.S. Pat. No. 3,986,563 (Stubben), each of which are assigned to the assignee of the present invention.
What is needed in the art is a blade positioning assembly which allows movement of the blade relative to the main frame while at the same time providing increased visibility to the blade and front axle.
The present invention provides a blade positioning assembly that is mounted to the underside of the main frame. A pivot member in the form of a mounting ring is attached to the bottom of the main frame. A blade lift member is attached to the bottom of the mounting ring to keep the blade lift member in line with the axle and thereby allow for more visibility around the blade lift member, front axle and tires.
The invention in one form is directed to a motor grader including a base unit and a blade positioning assembly. The base unit has a main frame. The blade positioning assembly includes a pivot member attached to and extending downwardly from the main frame, and a blade lift member attached to a bottom end of the pivot member.
The invention in another form is directed to a blade positioning assembly for use in a motor grader having a longitudinally extending main frame. The blade positioning assembly includes a pivot member attachable to a bottom side of the main frame, and a blade lift member attached to a bottom end of the pivot member and pivotally movable relative to the pivot member.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates an embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
Referring now to
Blade lift member 28 is attached to the bottom end of pivot member 26 to improve the visibility to the front axle and blade 18 (
Blade lift member 28 is selectively pivotally movable relative to pivot member 26. To accomplish the pivotal movement therebetween, an arcuate mating groove arrangement 46 includes a groove 48 formed in the rear surface of pivot member 26 with a radius of curvature which is generally parallel to bottom surface 32 (
A plurality of retainers 52 retain blade lift member 28 to pivot member 26. Each retainer 52 includes a forwardly extending lug 54 and an attached radially extending ear 56. Retainers 52 retain the plurality of bosses 50 within arcuate groove 48 to thereby retain blade lift member 28 to pivot member 26.
Blade positioning assembly 20 also includes one or more mechanical stops 58 for locking blade lift member 28 at a selected pivotal or angular location relative to pivot member 26. In the illustrated embodiment, two of the four forwardly extending bosses 50 have a central hole 60 through which a locking pin 62 passes and is received within a corresponding one of a plurality of holes 64 formed in pivot member 26 (
Referring now to
In summary, blade lift member 28 attaches to the bottom of pivot member 26 that is attached to the bottom of main frame 14. Blade positioning assembly 20 uses retainers 52 on one side of the pivot member 26 and a guide in the form of arcuate mating groove arrangement 46 on the other side to allow it to rotate around pivot member 26 while being retained. Blade positioning assembly 20 uses one or more locking pins 62 to hold it in place at discrete angles. Moving the locking pin holes 64 closer together near the bottom of the main frame allows the distance between the locking pin holes to shrink and allows for removing the upper part of the pivot member 26 material since it is no longer needed for retention of the blade lift member 28. This provides better visibility straight ahead over the main frame 14.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
