The present invention relates generally to land working implements, and more particularly to towable land levelers having tiltable land-working blades.
Applicant's prior PCT Application, published as WO/2016/109882, disclosed a towed land leveler implement whose frame was supported for rolling movement over the ground via a pair of split-beam walking beam assemblies on opposing sides of the frame. Front and rear beams of each split-beam walking beam assembly are pivotal relative to one another by an actuator, whereby changing the angle between the front and rear beams lifts or lowers the main pivot of the walking beam in order to adjust the height of the respective side of the vehicle frame. Through independent operation of the two walking beam actuators, the two walking beams can be used to adjust the tilt angle of a ground-working blade carried on the frame.
Disclosed herein is a novel improvement to this or other land levelers likewise having a tiltable ground working blade.
According to one aspect of the invention there is provided a towable implement comprising:
a frame supported for traveling movement over underlying ground;
a pull tongue connected to the frame and spanning forwardly thereof in a longitudinal direction of the implement for selective coupling to a tow vehicle for puling of said frame forwardly over said underlying ground;
a working blade carried on the frame in an orientation lying transversely of the longitudinal direction, said blade being operable in a working state in which a portion of a lower working edge of said working blade is engaged with said underlying ground to perform a working operation thereon;
wherein:
One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
In the drawings like characters of reference indicate corresponding parts in the different figures.
The novel box blade assembly of the present invention differs from Applicant's aforementioned prior PCT application in the inclusion of a series of rigid, rudder-like fins 100 attached to an underside of the box blade at discretely spaced intervals thereacross, whereby this novel bottom-finned blade arrangement is operable to help maintain straight travel of the implement 10 even when used in a tilted-blade condition where only a partial fraction of the blade width engages the underlying land, or where different parts of the blade width engage the underlying land to different depths. In such scenarios, the degree of resistance to forward travel of the blade is different at the differently submerged portions of the blade width, and this uneven loading of the blade across its width causes an unintended steering effect tending to swing the implement of a straight-travel position properly aligned behind the towing vehicle. Engagement of at least some of the fins with the earth provides a rudder-like effect resisting such unintended steering of the implement out its desired straight-travel position properly inline with the towing vehicle. The fins are also useful to help maintain the proper straight-travel position of the implement in other situations where conditions exist that would tend to deviate the implement from this position, for example during travel of the implement across a hillside or other sloped terrain, where gravity imparts a steering influence away from the proper straight-travel position.
More detail concerning this novel bottom-finned configuration of the blade is provided further below with reference to
When the implement is on horizontal ground and situated in a level-blade configuration holding the box blade parallel to the underlying ground, the pull tongue 12 lies in a vertically oriented central longitudinal plane of the implement. The rear blade 18 spans from one side of the central longitudinal plane to the other in an orientation perpendicular thereto, thus placing each lateral end of the rear blade 18 at an outboard location horizontally outward from the tongue 12. At each end of the blade 18, a respective planar end wall 20 projects forwardly therefrom in a plane parallel to the tongue 12. Box blade structures of this type are known in conventional land leveler designs, and thus are not described herein in further detail. As is also well known in the art, the tongue 12 extends forwardly from the box blade assembly 16 to the hitch connector 14 at the fore end of the tongue, which therefore defines the forward or leading end of the overall machine by which it is pulled by a tractor or other suitable tow vehicle.
With reference to
The forward end of each longitudinal frame member 26 features a pivotal connection 28 to the blade 18, which enables pivoting of the frame assembly 22 relative to the box blade assembly 16 about a pivot axis that lies perpendicularly transverse to the tongue and parallel to the blade 18 and the main cross-member 24. The pivotal connections 28 of the two longitudinal frame members 26 to the blade 18 share this same pivot axis, which due to its orientation, may be considered to be a pitch axis P of the implement 10. As best shown in
Each longitudinal frame member 26 defines a respective side of the frame 22 on a respective one of the two opposing sides of the central longitudinal plane of the machine. Near the rearward end of each longitudinal frame member 26 that lies distally of the cross-member 24, a pivot pin or stub shaft 38 passes transversely through the longitudinal frame member 26 in a direction parallel to the pitch axis P, and projects outwardly from the longitudinal frame member 26 through front and rear beams 40, 42 of a respective split walking beam assembly 44 in order to pivotally connect same to the frame 22. Like a conventional walking beam, this split walking beam assembly 44 rotatably supports a pair of wheel axles 46, 48 near its opposing ends, so that two wheels 50, 52 mounted on these axles are rotatably carried on the walking beam in tandem positions relative to one another. The wheel axles 46, 48 lie parallel to the pivot pin or stub shaft 38. However, instead of the front wheel 50 and rear wheel 52 being rotatably supported on the same rigid beam, the front wheel 50 is rotatably carried on the front beam 40 that spans a front half of the overall walking beam assembly 44, and the rear wheel 52 is rotatably carried on a rear beam 42 that spans a rear half of the overall walking beam assembly 44. In the fore-aft longitudinal direction of the implement, the front end of the front beam is spaced forwardly of the forward end of the rear beam in the long, the rearward end of the rear beam is spaced rearwardly of the rear end of the front beam, and the front and rear beam overlap one another at the forward end of the rear beam and rear end of the front beam.
In each split walking beam assembly 44, the front and rear beams 40, 42 lie side-by-side with one another a short distance to the outside of the respective longitudinal frame member 26, and each feature a respective upright lug 58, 60 projecting upward from the topside of the beam 40, 42. A respective hydraulic cylinder actuator 62 of each walking beam assembly 44 has its opposing ends pivotally coupled to the front and rear top lugs 58, 60 by pivot pins whose axes lie parallel to the pitch axis P of the machine.
The stub shaft or pivot pin 38 passing through the respective longitudinal frame member 26 also passes through both the front and rear beams 40, 42 of the respective walking beam assembly 44 at an area where the two beams 40, 42 overlap in the longitudinal direction of the machine. The stub shaft or pivot pin 38 thus defines a main walking beam pivot axis W on which the collective walking beam assembly is pivotal relative to the frame 22, and also defines a coincident second walking beam pivot axis about which the front and rear beams 40, 42 are pivotable relative to one another by extension and retraction of the walking beam actuator 62. This direct coupling together of the front and rear wheel carrying beams of the walking beam assembly by the same shaft or pin that couples the walking beam assembly to the frame 22 reduces the number of parts by avoiding an intermediary between the front and rear beams on which the front and rear wheels are mounted and sharing the same pivot point for both the relative pivoting between the front and rear beams and the pivoting of the overall walking beam assembly relative to the frame.
When the length of the walking beam actuator 62 is maintained, an angle α measured between the front and rear beams 40, 42 about the axis of the stub shaft or pivot pin 38 walking beam assembly 44 is likewise maintained, and the walking beam assembly acts as a conventional walking beam in which the positions of the two wheels 50, 52 are stationary relative to one another. On the other hand, each side of the frame 22 can be raised and lowered relative to the ground G by varying the angle α between the front and rear beams 40, 42 through extension and retraction of the respective walking beam actuator 62. Particularly, if angle α is measured between the undersides of the two beams 40, 42, then extending the length of the actuator 62 pushes apart the front and rear lugs 58, 60 at the topsides of the beams 40, 42, thus forcing the undersides of the two beams toward one another and reducing the angle α. This pushes each of the two wheels 50, 52 downwardly against the ground G on an arcuate path about the stub shaft or pivot pin 38, thereby lifting the respective side of the frame 22 upwardly away from the ground G. Conversely, retracting the length of the actuator 62 draws the front and rear lugs 58, 60 toward one another, thus drawing the undersides of the two beams away from one another and increasing the angle α in order to lower the respective side of the frame 22 downwardly toward the ground G. By using the actuator 62 of each walking beam assembly to vary the positions of the two respective wheels 50, 52 relative to one another about the respective stub shaft or pivot pin 38, the height of each side of the frame can thus be varied, and the heights at the opposing sides of the frame can be set to different values in order to tilt the frame 22 and the connected box blade assembly 16 about a longitudinal roll axis R that lies perpendicular to the pivot axes W of the walking beam assemblies 44.
In the illustrated embodiment, the front beam 40 of each split walking beam assembly 44 resides adjacent the outer side of the respective longitudinal frame member 26, and the rear beam 42 resides opposite the longitudinal frame member 26 to the outside of the front beam 40. The rear wheel 52 is mounted to the inside of the rear beam 42, thus riding on the ground in a position trailing behind the longitudinal frame member 26 in the shadow of same. The front wheel 50 is mounted to the outside of the front beam 40, i.e. on the side thereof opposite the frame 22. The front wheel 50 resides nearer to the plane of the respective end wall 20 of the box blade assembly 16 than the rear wheel, but still a short distance inboard from this plane. By placing the two wheels of each walking beam assembly on opposite sides thereof, the wheels are slightly spaced apart from one another in the transverse direction of the machine. This way, a rock, bump or other surface disruption on the ground that is met by one wheel will not necessarily be hit by the other.
The implement may be equipped with a control system for monitoring and automatically controlling the tilt angle of the frame and blade about the roll axis R, and this may be of the type described in Applicant's aforementioned PCT application, the entirety of which is incorporated herein by reference. Although some embodiments of the present invention may employ the automated control of the blade angle, other embodiments may be manually controlled by the operator of the tow vehicle, for example by conveying electrical control signals from a manual lever or other control mechanism in the operator cabin of the tow vehicle to the directional control valve, for example via suitable wiring run along the pull tongue 12 of the implement, or by way of a wireless communication link.
While the illustrated embodiment features two split walking beam assemblies 44, another embodiment may feature one conventional fixed-beam walking assembly, whereby the tilt angle of the blade is set by adjusting the one split walking beam assembly to set the height at one side of the frame, without changing the height of the other side of the frame. While some embodiments with two split walking beam assemblies may employ hydraulic control system that automatically operates the two walking beam actuators in inverse of one another, other embodiments are also contemplated. For example, split walking beam assemblies on opposing sides of a vehicle or implement (whether a land leveler, or other machine) may be beneficial even with other control configurations, for example in a control configuration where the two walking beam actuators are again operated simultaneously, but in the same direction, so as to control and overall height of the vehicle, or in a control configuration in which the two walking beam actuators are operable independently of one another, for example to set a desired height at one side of the frame, and a desired tilt angle of the frame.
The inclusion of the rigid fins 100 along the bottom of the blade 18 can be seen in
The main body 102 and mounting flange 104 of each rigid fin 100 are preferably seamlessly integral parts of unitary metal body having a right angle between these two integral parts. The shape of the illustrate fin is further characterized a concavely contoured leading edge 108A, terminating at a relatively sharp point or tip 110A at its bottom end, where the leading edge 108 intersects with a bottom edge 112 of the fin. In the illustrated example, the fin has a symmetric shape, thus having a matching concavely curved trailing edge 108B also terminating in a relatively sharp point or tip 110B. Each fin is thus reversable, whereby once the leading edge has been subjected to notable wear from repeated use, the fin can be removed, and flipped into a reverse orientation placing the formerly rearward facing trailing edge 108B into a forwardly facing position, and likewise placing the formerly forward facing leading edge 108A into a rearwardly facing position. The pointed configuration of these edges at their distalmost terminus helps reduce resistance of the fin to movement through the earth.
Referring to
A mounting structure 118 of the blade is attached to and spans between the two end walls 20 of the box blade assembly 16 at a location behind the curved blade wall 114 and beneath the convex rear side 114B thereof for the purpose of mounting the rigid fins 100 to the box blade assembly 16. The mounting structure has a bottom wall 120 whose front edge meets the rear side 114B of the curved blade wall 114 at the terminal lower end thereof just behind the wears strip 116, whereby this bottom wall 120 of the mounting structure resides in a plane parallel to the working plane at a slight elevation thereabove. In the illustrated example, the mounting structure has an L-shaped cross-sectional shape when cross-sectioned parallel to the central longitudinal plane of the implement, and thus is characterised by an upright rear wall 122 standing upright from the bottom wall 120 of the mounting structure at rear end thereof. The bottom wall and rear wall of the mounting structure cooperatively form a channel like space running along the rear side of the curved blade wall. At spaced intervals along this channel space are a series of blade-reinforcing gussets 124 that brace against all three of the rear side 114B of the curved blade wall 114, the bottom wall 120 of the mounting structure, and the rear wall 122 of the mounting structure.
The underside of the mounting structure's bottom wall 120 denotes a mounting surface against which the mounting flange 104 of each rigid fin 100 abuts in flush relation thereto. Since the mounting structure's bottom wall 120 is slightly elevated above the working plane of the blade, the mounting flange 104 of each rigid 100 likewise resides in slightly elevated relation above the working plane, or at least no lower than said working plane. Accordingly, only the main body 102 of each rigid fin reaches downwardly beyond the working plane of the blade's working edge 116A, whereby the integrity of the fins attachment to the mounting structure 118 is not subject to direct wear exposure during use of the implement. With reference to
Still referring to
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the scope of the claims without departure from such scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.