LASER CONTROLLED LAND LEVELLING MACHINE

"LASER CONTROLLED LAND LEVELLING MACHINE"

DESCRIPTION

The present invention relates to a laser controlled land levelling machine. State of the Art

As it is already known in the art, a land levelling laser controlled machine is a towed machine, partially self supported, and provided of a levelling blade for the moving of land material from one place to another.

This kind of machine it is used in agriculture, for example in a paddy farmland or other different crops lands, or even in industry, for the implementation of, for example, industrial buildings, and also for the preparation of tennis courts, golf courses, football, athletics avenues, roads, etc. For the function, upon set a plan on a transmitter, the levelling machine receives data through an automatic control unit and copy the same to the ground floor previously set, transforming the received signal in an electrical signal for the control of the controlling valves of the levelling blade, or lifting or lowering the same, thereby obtaining a plan that is perfectly correspondent to the copy of the plan that the transmitter is creating. The operator must simply driving the tractor during the operation. An object of the invention is to provide a central part of the supporting structure of the machine which supports at the rear end thereof an end part of the control cylinder of the laser levelling blade, which be of extremely ease of construction, therefore having a very low production cost for the same, and at the same time that support all the bending and twisting stresses during the working condition, and that be reliable and tough.

On the other hand, in the abovementioned known machines the to lift the lifting arms have to be removed during the use, as these interfere and strike against the chassis of the machine upon the steering thereof, forcing the operator to remove temporarily the lifting arms when the levelling machine is driven, with consequent disadvantage of the use thereof.

In the already known machines, in the case of a machine having two carriages and each comprising three wheels on one side, there is provided a shifting system called "tilting or balancing system" integrally mounted onto the shaft of the central wheel of the machine, the shaft of the former being connected to the levelling blade. Said system provides at one side thereof the hinged connection to an hydraulic control for the tilting of the shaft in a direction which is transverse to the direction of motion, thereby tilting the levelling blade accordingly, lifting or lowering the latter upon request and depending on the need to change the slope of the levelling blade with respect to the land. This tilting system it is used to cut the higher part of the land become harder after repeating passages of the tractor.

In the present systems, when the shaft is lifted to tilt the levelling blade, as a result of the elongation of the driving cylinder, the central wheel pops up with respect to two side wheels, thus abandoning the support onto the ground.

Conversely, when the shaft is lowered, the operation fails because the wheel solidarity with the central shaft prevents this movement. This leads to some disadvantages, such as less stability of the machine and relevant errors created on the slopes of land and that the laser continuously should correct the excursion of the controlling hydraulic controls for the levelling blade, resulting in a lower speed of execution of the work and an extra time of use.

Also in these known machines, usually the wheels arranged inwardly and toward the centre of the shaft always contact the land, not only during the moving of the machine from one site to another, but also during the operating condition thereof. This makes the machine unstable, particularly when said wheels meet a central area of a hump that the blade could not cut because it is below the level of the levelling floor of the laser. The machine is bound to raise up at the side of the hump, and the central wheels increase the effect at the levelling blade side, with all the inconveniences arising from the ensuing instability. The same applies in the case wherein the central wheels encounter a dip rather than a rise.

Object of the invention it is to overcome the above drawbacks, by providing an advantageous and reliable solution, both as embodiment and as employment thereof, and reducing the working time. Brief description of the invention

These objects are achieved by providing a laser controlled levelling machine according to the present invention that comprises a supporting frame having the central part thereof for the supporting of an end part of the laser controlled cylinder of the levelling blade, the frame being of extremely constructive ease, but at the same time supporting in a reliable manner all the bending and torsion stresses which is subject to, such supporting frame having a rear part supported by wheels, wherein in the case of three wheels on each side are provided, it is always ensured and maintained the support on the ground of all the wheels, and comprising means on one side of the machine for the aligning of said three wheels on that side, including the wheel corresponding to the central shaft which is integrally connected the levelling blade, disregarding the sloping upward and downward of the levelling blade during the function thereof and in order to change the slope of the blade with respect to the ground, and also disregarding the lifting or the lowering of the shaft connected to said levelling blade, and wherein the rear shaft has two opposing end arms, said arms being mounted in a tilting manner towards the outside of the machine and to the ground in the operating condition thereby supporting the wheels onto the ground, while at the same time the inner wheels are not contacting the ground by lifting the same, the inner wheels being deployed only for transporting of the machine from one site to another, and so as to increase the wheelbase of the machine and improving the stability.

Description of the figures The abovementioned and other features of the invention and its advantages will be apparent in the following detailed description of a preferred embodiment of the same, given by way of a non limiting example and with reference to the annexed drawings, wherein:

Fig. 1 is a front view of the laser controlled land levelling machine according to the invention, in a operating condition during transfer operations from a site to another;

Fig. 2 is a top plan view of the present levelling machine in a operating condition;

Fig. 3 is a front view of said of the present levelling machine in a operating condition;

Fig. 4 is a top plan view of a three wheels carriage of the present levelling machine according to the invention, showing connecting hinge means for sloping the rear shaft in a direction which is transverse to the direction of motion; Fig. 5 is a front view of the three wheels carriage referred to fig. 4, and viewed from the inner side thereof with respect to the rear shaft;

Figures 6 and 7 refer to the three wheels carriage of Fig. 5 in a standard functioning position where the central wheel is horizontal and substantially parallel to the ground, respectively in a inner view and an outside view with respect to said shaft;

Figures 8 and 9 refer to said three wheels carriage of Fig. 5 in the condition of lowering of the central shaft, respectively in a view from inside and a view from outside with respect to said shaft;

Figures 10 and 11 refer to said three wheels carriage of Fig. 5 in the condition of raising the central shaft, respectively in a view from inside and a view from outside with respect to said shaft;

Figures 12, 13 and 14 refer to a rear view of a levelling machine provided with said three wheels carriage of Fig. 5 in a operating condition, where aid rear shaft is respectively in a first horizontal condition, in a second condition tilted upward (raising), and in a third condition tilted down

(lowering), and transversely to the direction of motion of the machine;

Fig. 15 is a rear view of the levelling machine in a non-operating condition and in a transporting condition of the same; and

Figures 16 and 17 are top plan views of the rear shaft in two different conditions, and showing two hinged arms outwardly tilted and shaft's locking means, respectively in first unlocked condition and a second locked condition, and the inner wheels in a raised operating condition.

Detailed description of the invention

With reference to the figures, the levelling machine according to the present invention consists of a first supporting structure which includes a first front part comprising a frame substantially pyramid shaped and constituted by a pair of flat members 10 wherein the following devices are supported: an oil tank 11 for providing the oil to the actuators of said leveling machine, a levelling blade 12, and a structural tubular member 13 for the rigidity of said pair of flat members 10 and for the supporting of a hydraulic actuator 14 to be controlled via the laser control for the referenced positioning of the levelling blade 12 with respect to the ground.

The construction of said front part it is extremely simple in structure, and shows the advantage of entailing low costs for the making thereof, and at the same time having reliable performances and sturdy for the supporting of traction and shear stresses during the operating condition.

Said pyramid frame comprises a rudder 19 having an elongated shape for the connecting to a towing vehicle and such that said towing vehicle do not interfere during steering thereof with said rudder 19. The supporting structure of the levelling machine further comprises a rear part thereof being showed with the numeral 20 as a whole in the figures, which is hinged to said front part and includes two outer tip wheels carriages 15, and two inner central wheels 16.

The carriages 15 relevant to the outer wheels are supported by respective pair of arms 17 mounted in a hinged manner onto the rear shaft 21 , whilst said inner wheels 16 are integrally mounted onto said arms 17, by means of supporting arms 18 (Fig. 1).

According to a preferred embodiment of the invention, the rear part 20 of the supporting structure comprises at respective side thereof at least a carriage 15 having three wheels, where two wheels being side wheels 22a and 22b, and a centre wheel 23 which is aligned or coaxially mounted to said rear shaft 21 , the shaft 21 being integrally connected to the levelling blade 12. Said carriage 15 has said two side wheels 22a and 22b connected to a pair of plates 24 mutually hinged at a first point 25 of a part of said supporting structure, and wherein the angular motion upwardly (Fig. 10 and 11) or downwardly (Figures 8 and 9) are determined by an hydraulic actuator 26, the arrangement being such that the shafts 27, 28 and 29 of all of said three wheels 22a, 23 and 22b, respectively are connected to a flat bar 30 connected to said shafts 28 (corresponding to the inner centre wheel 23) and 29 (corresponding to said side wheel 22b), whilst the shaft 27 of the side wheel 22a it is slidingly mounted in a slot 31 of the said bar 30. With this arrangement the shafts 27, 28 and 29 of all of the three wheels, respectively 22a, 23 and 22b, are always aligned.

Accordingly, it is advantageously noted that the support onto the ground of all said three wheels 22a, 23 and 22b it is always guaranteed, especially during the displacements upwardly (Figures 10 and 11) and downwardly (Figures 8 and 9) of the shaft 28 when aligning to the shaft 21 of the centre wheel 23, which is determined by the raising or lowering of the two plates 24 supporting the two side wheels 22a and 22b (Figures 10 and 11), and as a consequence of the displacement of the hydraulic actuator 26, i.e. when the actuator 26 is extended (raising) (Figures 10, 11 , and 13), or when it is retracted (lowering ) (Figures 8, 9 and 14).

On the other hand, figures 5, 6, 7 and 12 show the condition where the shaft 21 it is arranged in a horizontal condition and substantially parallel to the ground. In this condition, said three shafts 27, 28 and 29 of corresponding said three wheels 22a, 23 and 22b of the carriage 15, are arranged in order to guarantee always the support onto the ground of all said three wheels, therefore guaranteeing a better stability to said land levelling machine, which leads to a faster execution of the work and a lower operating time.

According to another feature of the land levelling machine of the present invention, it comprises a pair of arms 17 mounted in a hinged manner onto the rear shaft 21 , and each arm 17 has mounted thereon a carriage 15 having three wheels, further comprising blocking means for the blocking of said pair of arms 17 onto the shaft 21. With reference to the figures 2, 3, 12, 13, 14, 16 and 17 the arrangement is such that during operating condition of said land levelling machine, said arms 17 are fully arranged outwardly with respect to the rear shaft 21 causing said wheels of each carriage 15 to be supported onto the ground and said blocking means blocking the swinging of said arms 17 with respect to the shaft 21.

With reference to Fig. 1 , each inner wheel 16 is supported by means of a respective arm 18, each arm 18 being mounted onto said arms 17, the arrangement being such that in the operating condition (as shown in figures 2, 3, 12, 13, 14, 16 and 17) upon tilting outwardly said arms 17 supporting the carriages 15 of wheels, the inner wheels 16 are consecutively raised, therefore the latter don't lying onto the ground and being excluded while the wheels of the carriages 15 are onto the ground. On the other hand, upon raising said arms 17 (as shown in figures 1 and 15), the pair of inner wheels 16 contemporaneously touch the ground, and in this condition the land levelling machine is transported in a non operating condition.

Therefore, in the operating condition said wheels of carriages 15 touch the ground after tilting outwardly of said respective arms 17 hinged onto said rear shaft 21 of the present land levelling machine, and contemporaneously and automatically excluding the inner wheels 16 which are raised, this arrangement causing according to a further advantageous feature of the invention an improved stability of the land levelling machine during the operating condition thereof, by means of the sole outer wheels of said carriages 15.

On the other hand, said blocking means (as shown in figures 16 and 17) of said arms 17 and said shaft 21 , comprises a kinematics hydraulic leverage shown with the reference numeral 32, which upon the displacement thereof automatically blocks/unlocks in a reversible manner the hinges of said arms 17 by locking/unlocking a pair of hook shaped members 33 mounted in a hinged manner and within respective abutments 34 integrally obtained on each arm 17 at the hinge area thereof.

According to the present embodiment the tilting motion of the arms 17 supporting the carriages 15 of wheels is determined by an hydraulic actuator 35 connected to said arms 17 at the hinge area, the arrangement being such that the actuator 35 during its motion for the raising of said arms 17, by means of said hydraulic leverage 32 acting onto said arms 17, causes the unlocking of each arm 17 from the shaft 21 by means of unlocking the hook 33 integral onto said arms 17 from its abutment 34 integral onto said shaft 21 , and after reaching its final motion the arms 17 will be raised. Viceversa for the lowering of the arms 17 and after the final motion of the actuator 35, each hook 33 will be engaged on its respective locking abutment 34 and after the arms 17 are fully tilted outwardly abutting the shaft 21 , the actuator 35 will further displace determining the locking of said hooks 33 into said respective abutments 34 thereby locking said arms 17 onto said rear shaft 21. In this condition, it must be noted that the actuator 35 it is not stressed since the same it is not biased by the shaft 21 nor by the arms 17 being both mutually blocked, and the actuator being integral to the arrangement shaft 21 and arms 17, thereby the whole arrangement advantageously guaranteeing high rigidity to the whole frame.

It will be apparent to those skilled in the art that according to different embodiments, each arm 17 may support carriages 15 having two wheels or alternatively three wheels.