Mounting assembly for mounting implement to a vehicle

A mounting assembly (6) for mounting a bulldozer blade (2) to a vehicle (4) is disclosed. The assembly comprises a lower link (8) adapted to be mounted to a vehicle, a pair of first actuators (16, 18) adapted to be pivotably mounted to the blade, and to a pair of link plates (24, 26) via respective pin joints (28, 30), and a pair of second actuators (36, 38) adapted to adjust the position of respective pin joints (28, 30) relative to the lower link to adjust the orientation of the blade relative to the vehicle.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No. EP 12159895, filed Mar. 16, 2012, titled “Mounting Assembly for Mounting Implement to a Vehicle,” and UK Patent Application No. GB 1204654.6 filed on Mar. 16, 2012, the contents of both of which are hereby incorporated by reference in their entireties herein.

FIELD

The present invention relates to a mounting assembly for mounting an implement to a vehicle, and relates particularly, but not exclusively, to a mounting assembly for mounting a bulldozer blade to a military work vehicle.

BACKGROUND

Blade mounting assemblies for mounting bulldozer blades to vehicle bodies are known. These often include mechanisms which allow the lift (height of the blade relative to the vehicle), pitch (orientation of the blade about an axis generally normal to the vehicle centre line plane), angle (orientation of the blade about a generally vertical axis) and tilt (orientation of the blade about a generally horizontal axis parallel to the vehicle centre line plane) to be adjusted for particular operations. Military work vehicles generally operate as conventional bulldozers, i.e. clearing debris, filling holes and so on, but in some cases also function as “earth anchors” in which the blade is buried deeply in the ground to provide a secure anchor to allow the vehicle, fitted with a suitable winch, to recover other vehicles stuck in soft terrain.

Since the blade is generally designed to be fitted to heavy vehicles, the assembly may be subjected to very high loads. For example, if the edge of the blade strikes a sufficiently immovable obstacle while bulldozing, the vehicle will be stopped almost instantly. The loads in the assembly in such a situation may be very large compared to normal bulldozing loads.

At the same time, it is also desirable to be able to adjust blade angle, for example when clearing snow from a carriageway to a roadside. In one known arrangement, one or more powered actuators are connected between the blade and a frame in order to rotate the blade relative to the frame. Such arrangements suffer from the disadvantage that when the blade is facing straight ahead, the actuator cylinders are partly extended, usually at their mid-point of travel, and actuators are then further extended and/or contracted to turn the blade left or right from its mid position. The blade is typically held rigidly in the mid position by locking the actuators. Since hydraulic cylinders are usually used as actuators, these are locked by closing hydraulic valves connected to the cylinder ports, preventing oil leaving or entering the cylinder, and thus preventing the cylinders extending or contracting. In order to avoid damage to the cylinders by excess pressure or buckling, hydraulic circuits typically include pressure relief valves which override this lock if a sufficiently high external force results in hydraulic pressures above some set threshold value, for example as a result of the blade edge striking some sufficiently immovable object and if the moving vehicle has sufficient mass and speed.

Such arrangements suffer from the disadvantage that in order to increase the size of load which the assembly can withstand, larger hydraulic cylinders need to be used, which significantly increases the weight and volume of the assembly.

SUMMARY

Preferred embodiments of the present invention seek to overcome the above disadvantage of the prior art.

According to an aspect of the present invention, there is provided a mounting assembly for mounting an implement to a vehicle, the assembly comprising:—

a body adapted to be mounted to a vehicle;

at least one pair of first actuators; each said first actuator being adapted to be pivotably mounted, at a respective first pivot, to one of said body or an implement;

a plurality of first link members, each said first link member being pivotably mounted, at a respective second pivot, to a respective said first actuator and adapted to be pivotably mounted, at a respective third pivot, to the other of said body or said implement;

characterised by a plurality of second actuators, each said second actuator being adapted to adjust the position of a respective said second pivot relative to the body to adjust the orientation of the implement relative to the vehicle,

wherein at least one said first link member and the corresponding said first actuator are arranged in use such that a line directly connecting said first and second pivots is arranged at an obtuse angle to a line directly connecting said second and third pivots, and at least one said second actuator is adapted to move the corresponding said second pivot from one side of a line directly joining the corresponding said first and third pivots to the other side of said line.

By providing first link members pivotably mounted at respective second pivots to first actuators and second actuators for adjusting the position said second pivots relative to the body to adjust the orientation of the implement relative to the vehicle, this provides the advantage of enabling the distance between the implement and an adjacent part of the vehicle to be reduced by means other than reducing the length of one or more of the first actuators. As a result, the implement can be in its angular mid position with fully compressed first actuators, which provides the advantage of significantly increasing the compressive forces which the assembly can withstand by means of actuators of a given size, as a result of which a lighter and more compact mounting assembly can be used for a given load.

This also provides the advantage of enabling compressive loads tending to cause the obtuse angle to change to be resisted by means of a more compact second actuator when in tension, thereby further contributing to reduction in weight and volume of the assembly.

This also provides the advantage of enabling the angle of the implement relative to the vehicle to be adjusted by means of a more compact assembly.

At least one said first link member and the corresponding said first actuator may be arranged such that loads urging the implement towards the vehicle in use tend to decrease the size of said obtuse angle.

At least one said second actuator may be arranged such that loads urging the implement towards the vehicle in use cause tensile loading of said second actuator.

This provides the advantage of enabling the loads to be resisted by means of a more compact second actuator.

At least one said second actuator may be pivotably mounted at a respective fourth pivot to said body.

The assembly may further comprise at least one third actuator for adjusting the orientation of the body relative to the vehicle.

At least one said third actuator may be adapted to cause pivoting of the implement relative to the vehicle about a first axis, and said first and second actuators may be adapted to cooperate to cause pivoting of the implement relative to the vehicle about a second axis substantially perpendicular to said first axis.

At least one said third actuator may be adapted to be pivotably mounted relative to the vehicle and to the implement.

The assembly may comprise a plurality of said third actuators.

This provides the advantage of providing a further degree of freedom of pivoting of the implement relative to the vehicle, by means of extending at least one said third actuator and/or contracting at least one said third actuator.

The assembly may further comprise at least one second link member adapted to be pivotably mounted relative to the implement and to the vehicle to adjust the orientation of the implement relative to the body as the orientation of the body relative to the vehicle changes.

This provides the advantage of enabling automatic pitch control of the implement when the implement is a bulldozer blade without the need for an additional actuator, thereby minimising increases in weight and volume of the assembly.

According to another aspect of the present invention, there is provided a vehicle comprising:

a vehicle body;

an implement; and

a mounting assembly as defined above connected to said vehicle body and said implement.

DETAILED DESCRIPTION

Referring toFIGS. 1,2and5, a bulldozer blade2is attached to a vehicle4by means of a mounting assembly6embodying the present invention. The assembly6comprises a body in the form of a lower link8connected to the vehicle4by means of a pin joint10, the axis of the pin joint10being generally perpendicular to a vehicle centre line plane12(FIG. 2). The lower link8is connected the blade2by means of a ball joint14(FIG. 5).

A pair of first actuators16,18are connected to the blade2by respective ball joints20,22and to respective first link members in the form of link plates24,26by means of respective pin joints28,30. The link plates24,26are connected to the lower link8by means of respective ball joints32,34(FIG. 5). A pair of second actuators36,38are connected to the lower link8by respective ball joints40,42and to the respective link plates24,26and actuators16,18at the respective pin joints28,30such that the actuators16,18and respective link plates24,26form respective obtuse angles to each other in the arrangement shown inFIG. 2. As a result, high loads tending to urge the blade2towards the vehicle4will result in high compressive loads in the actuators16,18and link plates24,26tending to urge the respective pin joints28,30outwardly to reduce the size of the respective obtuse angles, this movement being resisted by tensile loads in the respective actuators36,38which can be resisted by means of a more compact actuator design, since actuators are more effective in tension than in compression.

A pair of third actuators44,46are connected to the blade4by respective “point on line” joints48,50. As will be appreciated by persons skilled in the art, a “point on line” joint is a joint having one translational degree of freedom and three rotational degrees of freedom, for example a plain spherical bearing which can slide along a pin. In the arrangement shown inFIG. 2, the axis of the translational degree of freedom is fixed normal to the centre line plane52of the blade2. Left actuator46is connected to the vehicle4by means of a pin joint54, the structure connecting the pin joint54to the vehicle body being omitted from the Figures for clarity, and the axis of the pin joint54is generally perpendicular to the vehicle centre line plane12. Similarly, right actuator44is connected to the blade2by “point on line” joint48and to the vehicle body by means of a pin joint56. Again, the structure connecting the pin joint56to the vehicle body is omitted from the Figures for clarity.

A top link58is attached to the vehicle body by means of a ball joint60and to the bulldozer blade2by means of a ball joint62. Referring toFIG. 3, the blade2is raised relative to ground plane64by retraction of actuators44,46so that the blade2and mounting assembly6fit within an envelope66bounded by an approach angle plane68and a sight or gun line plane70. This enables the apparatus to be effectively stowed when not in use.

Referring now toFIG. 4, extension of the actuators44,46causes the assembly6to lower the blade2deeply below the nominal ground plane64. This enables secure earth anchoring to be carried out.

Referring toFIGS. 2 and 5, in order to adjust the angle of the blade2relative to the vehicle4body, one of the second actuator36is extended and the other second actuator38is contracted. This urges one pin joint30outwardly of the assembly6and withdraws the other pin joint28inwardly, as a result of which the respective first actuators16,18and corresponding link plates24,26pivot relative to each other. As can be seen fromFIG. 5, the pin joint28moves from one side of a line directly connecting the ball joints24,34to the other side of that line, thereby enabling the distance between the blade2and the adjacent part of the vehicle4to be reduced by means other than retraction of the actuator18. This movement is also assisted by means of connection of the lower link8to the blade2by means of ball joint14. Since the blade2is also connected to the upper link58by means of a ball joint62, the blade2can rotate about an axis passing through the ball joints14,62.

Finally, referring toFIG. 6, by extending one of the third actuators44,46and contracting the other actuator, the blade2can be arranged in a tilted position for penetrating hard ground.