FIELD OF THE INVENTION
The present invention relates to a differential dozer blade lift and angle mechanism. In particular, the present invention relates to an arrangement for controlling both the lift and angle of bulldozer blades using a pair of actuators.
BACKGROUND OF THE INVENTION
Prior art power-angle blades for dozers use at least four linear actuators to both lift the blade and angle the blade to the direction of travel. Two of these are used to operate the blade lift mechanism and the other two to adjust the blade angle. This leads to a more complicated and heavier mechanism.
SUMMARY OF THE INVENTION
In order to address the above and other drawbacks there is provided an earth moving vehicle for moving earth along a surface. The moving vehicle comprises a machine body comprising a forward end, a source of motive force and at least one wheel for conveying the motive force to the surface and such that the machine body is moved in a direction faced by the forward end, a push member comprising a first end pivotally mounted to the machine body for rotation about a lift axis, an elongate blade positioned in front of the forward end and comprising a front face facing generally away from the forward end, a lower long edge arranged adjacent the surface and a rear face opposite the front face wherein the rear surface is pivotally attached to a second end of the push member for rotation about an angle axis, and a pair of linear actuators, each actuator independently controlled and comprising a first end pivotally attached to the machine body for rotation about a third axis and a second end attached to the rear face on respective side of the second end of the push member, wherein the lift axis and the third axis are arranged in parallel, wherein the lift axis and the angle axis are arranged at right angles, wherein the blade is raised and lowered about the lift axis by respectively simultaneously retracting or extending both of the linear actuators, wherein the blade is angled about the angle axis by extending or retracting a first of the linear actuators relative to a second of the linear actuators.
There is also provided an earth moving vehicle for moving earth. The earth moving vehicle comprises a machine body, a push member comprising a first end pivotally mounted to the machine body for rotation about a lift axis, an elongate blade positioned in front of the forward end and pivotally attached to a second end of the push member for rotation about an angle axis wherein the lift axis and the angle axis are arranged at right angles, a pair of hydraulic pistons, each piston comprising a first end pivotally attached to the machine body for rotation about a third axis and a second end attached to the blade on respective side of the second end of the push member, wherein the lift axis and the third axis are arranged in parallel, a source of hydraulic pressure, a pair of control valves, each of the valves controllably interconnecting the source of hydraulic pressure with a respective one of the hydraulic pistons, wherein operating both of the control valves such that both of the hydraulic pistons are one of simultaneously retracted or extended respectively raises or lowers the blade about the lift axis, and wherein operating at least one of the control valves such that a first of the hydraulic pistons is extended or retracted relative to a second of the hydraulic pistons angles the blade about the angle axis.
Additionally, there is provided a blade control assembly for an earth moving vehicle comprising a machine body, a push member comprising a first end pivotally mounted to the machine body for rotation about a lift axis and a blade pivotally attached to a second end of the push member for rotation about an angle axis. The assembly comprises a pair of linear actuators interconnected between the machine body and the blade, wherein the blade is raised and lowered about the lift axis by respectively simultaneously retracting or extending both of the linear actuators, wherein the blade is angled about the angle axis by extending or retracting a first of the linear actuators relative to a second of the linear actuators.
Furthermore, there is provided a blade control assembly for an earth moving vehicle comprising a machine body, a push member comprising a first end pivotally mounted to the machine body for rotation about a lift axis and a blade pivotally attached to a second end of the push member for rotation about an angle axis. The assembly consists essentially of a pair of linear actuators interconnected between the machine body and the blade, wherein the blade is raised and lowered about the lift axis and angled about the angle axis by the pair of linear actuators.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides a side plan view of an earth moving vehicle in accordance with an illustrative embodiment of the present invention;
FIG. 2 provides a top plan view of the earth moving vehicle according to FIG. 1 and in accordance with an illustrative embodiment of the present invention;
FIG. 3 provides a schematic diagram of a differential dozer blade mechanism when lifting and in accordance with an illustrative embodiment of the present invention;
FIG. 4 provides a schematic diagram of a differential dozer blade mechanism when angling and in accordance with an illustrative embodiment of the present invention;
FIG. 5 provides a partial side plan view of an earth moving vehicle in accordance with a first alternative illustrative embodiment of the present invention; and
FIGS. 6A and 6B provide respectively a partial top plan view and a partial side plan view of a crawler excavator in accordance with a second alternative illustrative embodiment of the present invention.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
Referring now to FIG. 1, a vehicle for moving earth, such as a bulldozer, and generally referred to using the reference numeral 10, will now be described. The vehicle 10 comprises a vehicle body 12 comprising a forward end 14 and a source of motive force 16 such as a diesel engine or the like. The source of motive force is interconnected with at least one wheel, or cog, 18 which conveys the motive force to the ground 20, illustratively via a track or the like 22 and in order to move the vehicle in forward or rearward direction.
Referring now to FIG. 2 in addition to FIG. 1, a push member 24, such as a C-frame or the like, is mounted to the vehicle body 12 and such that a first end 26 of push member 24 is rotatable about a lift axis 28 which is transverse to the vehicle body 12 and the general forward direction of travel of the vehicle 10. In this regard, the push member 24 may be C-shaped such that the forward end 14 of the vehicle body 12 is received within the mouth of the “C” and the outer ends 30 of the “C” are each configured to rotate about the lift axis 28.
Still referring FIGS. 1 and 2, an elongate blade 32 is positioned in front of the forward end 14 of the vehicle body 12. The blade 32 comprises a front face 34 facing generally away from the forward end 14 of the vehicle body 12 and in the direction of forward travel of the vehicle 10. A lower long edge 36 of the blade 32 is arranged adjacent the surface of the ground 20. The rear face 38 of the blade 32 is pivotally attached to a second end 40 of the push member 24 and for rotation about an angle axis 42, generally normal to the surface of the ground 20 and at right angles to the lift axis 28.
Still referring FIGS. 1 and 2, a blade control assembly comprising a pair of independently controllable actuators 44, 46, illustratively hydraulic pistons, which are fed by a hydraulic system (not shown) powered by the source of motive force 16, are provided. The first end 48 of each actuator 44, 46 is mounted to the vehicle body 12 for rotation about a common third axis 50. The third axis 50 is arranged in parallel to and generally above the lift axis 28. The second end 52 of each of the actuators 44, 46 mounted to the rear face 38 on a respective side of the second end 40 of the push member 24, illustratively using a universal-type mount 54. A person of ordinary skill in the art will understand that a small amount of angular movement may be provided for at the point of attachment of the first end 48 to the third axis 50, for example through provision of a fisheye joint or the like at the first end 48 of each of the actuators 44, 46, and in order to accommodate the small changes in lateral spacing between the second ends 52 of each of the actuators 44, 46 when the blade 32 is angled.
Referring now to FIG. 3 in addition to FIGS. 1 and 2, by illustratively simultaneously retracting both of the actuators 44, 46, for example by actuating a control valve 56 attached to a source of hydraulic pressure 58 and such that the second end 52 of each actuator 44, 46 is brought the same distance closer to the first end 48, a lifting force FLIFT can be brought to bear on the outer ends 30 of the push member 24 and such that the push member 24 is rotated in a lifting direction about the lift axis 28 and, as a result, the lower edge 36 of the blade 32 raised to a selected height H up to a maximum height HMAX. Similarly, by simultaneously extending both of the actuators 44, 46 and such that the second end 52 of each actuator 44, 46 is moved away from the first end 48 the same distance, the lifting force FLIFT is reversed and such that the push member 24 is rotated in a lowering direction about the lift axis 28 and, as a result, the blade 32 lowered to a selected height H down to a minimum height HMIN.
Referring to FIG. 4 in addition to FIGS. 1 and 2, by retracting or extending a first of the actuators 44 relative to a second of the actuators 46 and such that the distance between the first end 48 and second end 52 of the first actuator 44 is different from the distance between the first end 48 and second end 52 of the second actuator 46, the blade 32 can be rotated about the angle axis 42 and such that the front face 34 of the blade 32 is at an angle to forward direction of the vehicle 10. As a person of ordinary skill in the art will now understand, by adjusting the actuators 44, 46 a given angle Φ from the normal centred position A0 at right angles to the forward direction of the vehicle 10 can be selected between a maximum angles AMAX.
Referring to FIG. 3 in addition to FIGS. 1, 2, and 4, a person of ordinary skill in the art will now understand that a lifted and angled blade 32 can be arrived at. For example, the blade 32 may be lifted of the ground to a given height H and then once in this lifted position one or other of the actuators 44, 46 extended or retracted and such that the lifted blade is rotated about the angle axis 42 and such that the lifted bladed is angled relative to the direction of forward travel of the vehicle 10. Similarly, the blade 32 may be angled to a given angle A and then once in this angled position both the actuators 44, 46 simultaneously retracted and such that the angled blade 32 is lifted above the ground 20.
Referring now to FIG. 5, in a first alternative embodiment the rear surface 38 of the blade 32 is mounted to the second end 40 of the push member 24 such that the blade 32 may pitch about a pitch axis 60 arranged in parallel to the axis of the elongate blade 32. A third linear actuator, such as a hydraulic piston 62, is provided. Extending the hydraulic piston 62 allows the blade 32 to be pitched about the pitch axis 60 and such that the lower edge 36 of the blade 32 may be lowered or raised.
Referring now to FIGS. 6A and 6B, in a second alternative illustrative embodiment, the blade 32 is attached to a crawler excavator body 64 via a push member 24 and a pair of linear actuators 44, 46. As discussed above, operation of the linear actuators 44, 46 in the same direction together allows the blade to be lifted about the lift axis 28 and such that the blade may be raised to a given height H. Additionally, operation of one of the first linear actuator 44 or the second linear actuator 46 such that they are retracted or extended relative to one another allows the blade 32 to be angled to a given angle Φ from the normal centred position.
Although the present invention has been described hereinabove by way of specific embodiments thereof, it can be modified, without departing from the spirit and nature of the subject invention as defined in the appended claims.
Patent Application
20240247464
