WO2008018840A1

WO2008018840A1 - Lifting and manipulating device for tractors

Info

Publication number: WO2008018840A1
Application number: PCT/SI2007/000006
Authority: WO
Inventors: Rafko Voje; Drago Lebar
Original assignee: Hidravlika In Mehanika Raf D.O.O.
Priority date: 2006-08-08
Filing date: 2007-02-26
Publication date: 2008-02-14
Also published as: SI22336A

Abstract

The present invention relates to a lifting and manipulating device, which is adapted to co-operate with each existing manipulating mechanism (3, 4) of a tractor (2). Said device comprises a single vertical telescopic post (1), to which a lifting assembly (13) is mounted and which is firmly connected to a transversal beam (8), which is adapted to be attached to said tractor (2) and is moreover equipped with corresponding wheels (5', 5''), which may generally be rotated around the vertical axis (50) and/or horizontal axis (51), but such rotation may either be enabled or also eliminated, when desired. The device as such is characterized by excellent stability and manoeuvring properties, and in addition to that, the overview along each manipulating area is also very good during the use thereof.

Description

LIFTING AND MANIPULATING DEVICE FOR TRACTORS

Invention belongs to the field of transporting, namely to devices for lifting, hoisting or lowering bulky or heavy goods, which are movable with their loads by wheels. Furthermore, the invention may also relate to devices of previously specified art, which are hydraulically actuated or controlled and furnished wit a telescopic mast. Still further, the invention also relates to construction features or details of such devices.

The purpose of the invention is to create a lifting and manipulating device, which should be like any other known tractor accessories capable for attaching to a commonly used manipulating mechanism of a tractor, by which such device should moreover assure appropriate gripping and lifting of each load in the vertical direction and also manipulation of said load in at least approximately horizontal direction i.e. at least essentially parallel with respect to the ground, by which the manoeuvrability as well as driving and stability characteristics of the tractor together with the surmounted device including the load should be essentially improved, and at the same time also the visibility from the side of the tractor driver towards the manipulating area should remain essentially unhindered, which is of a great importance when bearing in mind safety steering of the tractor and in particular also manipulation of the load. Various appliances and devices are known to those skilled in the art, which enable gripping the load, lifting thereof in at least approximately vertical direction and also manipulation of the load in at least approximately horizontal direction i.e. parallel with respect to the ground. Such devices generally comprise suitable driving means, which on the one hand enable at least hoisting i.e. lifting and lowering of the load in the vertical direction, and on the other hand also manipulation of the load together with said load in the at least essentially horizontal direction along the disposable ground. By several simple devices (e.g. according to US 6,511,080) said lifting is performed on the basis of a hydraulic means, which is driven by means of a hand operated hydraulic pump, while on the other hand manipulation along the ground is merely possible by exploitation of muscles of each user.

On the other hand various special devices are known, which are furnished with autonomous driving system like an internal combustion engine or electric motor or the like, and in addition to an assembly adapted for driving and manipulating during lifting of the load in the vertical direction also comprise a further assembly, which is adapted for manipulation of load in the horizontal direction. Using such special devices is reasonable exclusively in such circumstances, where the need on lifting and horizontal manipulation permanently exists, since such special devices are normally unable to perform any other operations except of said operations, and would in any other circumstances obviously not be exploited in a sufficient extent. When bearing in mind any other circumstances, where some more universal devices are preferred, several universal devices are also known in the state of the art, which are among others also capable to perform lifting the load in the vertical direction and manipulating thereof in the horizontal direction. An approach may e.g. be surmounting of a suitable manipulating assembly for lifting of load to a classic truck or lorry (GB 1,054,976). Consequently, such truck may then be used both for lifting and also for perform ordinary transporting operations in a roadway traffic. However, in order to assure a required stability i.e. to prevent the truck of both turning-over and submerging, appropriate telescopic supporting jacks need to be rest on the soil, which however means, that each possibility of manipulation of the load in the horizontal direction is herewith practically eliminated. Accordingly, as soon as the load is lifted, said supporting jacks must be hoisted, whenever this is possible at all, upon which the load is horizontally transferred to each desired location, which is obviously complicated and time consuming, and may sometimes also be very risky or dangerous.

A group of devices is also known, which are adapted to be surmounted to an universal and commonly used tractor, which allows exploitation of various accessories and moreover excels in acceptable maneuverability. A hoisting device is described in JP 2001 341 989 A, which is surmounted to the front portion of a tractor. Such approach is comfortable when bearing in mind visibility, but not also with respect to maneuverability, since the driving wheels are arranged rearwards and the maneuvering wheels are arranged forwards. Besides, the three-point manipulating mechanism is available on the rearward portion of the tractor, which normally means, that in addition to said hoisting device at the same time an additional accessory may be used, while on the other hand surmounting of said hoisting device is feasible only in the case, when an additional mounting assembly with included driving and controlling assembly must be available on the forward portion of the tractor, which normally leads to a comprehensive modification of the tractor in order to assure appropriate functioning thereof in such circumstances. Of that reason and also when bearing in mind, that there is actually no need to use an additional accessories simultaneously with such hoisting device, the majority of actually used lifting devices are nowadays surmounted to the rear portion of the tractor, namely directly to said manipulating mechanism. Surmounting to the rearward portion normally leads to pretty undesired position for the user, which must draw his attention merely in the rearward direction, but at the same time is also maneuverability of the tractor during the steering in the rearward direction essentially improved, which is in particular important by approaching the load. Various embodiments of such kind may also be found in the patent literature.

A lifting device as described in US 4,394,107 is attached to the manipulating mechanism of the tractor and consists of telescopic U-section frames, which are guided in the at least approximately vertical direction guided along each other and are telescopically extracted by means of a suitable traction member, while on one of them a fork is attached, which is adapted for gripping and supporting the load. When the device is mounted on the tractor, but us not actually used, then said frames are introduced each into another, so that visibility in the rearward direction is not essentially hindered. However, serious problems may actually arises from the essential weight thereof, which may have an important impact to stability and maneuverability of the tractor, especially during manipulation of the load along the soil, which may be either flat or inclined, hard or soft, dry or wet. As soon as said frames are extracted, also the visibility becomes essentially hindered in particular in the rearward direction of steering the tractor, in which the load is transferred.

On the other hand, JP 2005 00179A or also e.g. JP 2006 199 399 A or US D 305,894 suggest a higher but essentially thinner frame, in which the load lifting fork is guided in the vertical direction. Also such frame includes at least two vertically extending members, which may essentially hinder visibility in the rearward direction towards the area of manipulating the load, which is in each case undesired any may also be very dangerous.

In connection with previous description it should be furthermore noted, that manipulation of loads extends on the ground, the configuration of which may also be essentially varied. Just presence of such device on the tractor may normally result in certain impact in respect of loading conditions of single tractor parts and also in respect of stability thereof, especially when bearing in mind overturning. During the loading operation and transferring of each load said loading and stability conditions may also essentially change. Additional loadings may e.g. occur on the rear wheels, which is however a minor problem. Releasing of loading in the area of front wheels, which occurs at the same time, my however result in partially or completely elimination of maneuverability of the tractor even if the soil is completely diy and hard. In addition to that it should be also taken into account, that the tractor together with such device and also the load normally are exposed to certain inertia during the movement, by which the inertia forces may also be directed in various directions, which depends on each particular maneuver and also on configuration of the soil, and may sometimes not be exactly foreseen or determined in advance, which may then easily lead to decrease of maneuverability and loss of control in respect of the tractor or the load and sometimes also to accidents.

One of possible approaches in order to avoid these problems is to furnish such lifting device with a pair of wheels. Accordingly, JP 10 2001 0058 604 A suggests a lifting device, which is adapted to be attached to a manipulating mechanism of the tractor and comprise a vertical frame, below which a pair of wheels is foreseen. In that particular case said wheels should merely serve for the purposes of determining a minimum distance between the device and the ground, which enables a desired functioning of such device, e.g. during the loading like e.g. or by the snow plough, by which anyway a real impact of said wheels to the maneuverability is more or less negative and not positive.

On the other hand US 6,543,566 Bl or also CA 2,295,272 Al suggest a lifting device, which is attached to the manipulating mechanism of a tractor and consists of a chassis, which may be attached below the front portion of the tractor. Said chassis comprises a transversal beam, on which two wheels are mounted, which may then be freely rotated around the vertical axis. In addition to that, said chassis is adapted to receive an at least vertically extending frame, which is intended to guide a lifting means together with forks. Surmounting of said chassis however requires either a modified concept of a tractor or an extensive modification of the existing tractor. The concept of surmounting on the front portion of the tractor may actually result in some better control of the load by transferring thereof in the forward direction, although the frame consisting of two vertically extending masts may hinder visibility in a certain extent. Besides, by moving the tractor in the forward direction the maneuverability is essentially worse than by moving in the rearward direction. The front wheels are intended merely for the purposes of maneuvering and not so much for the purposes of taking-over additional loadings, and correspondingly the wheels on said chassis are pretty large in order to bear the loadings by themselves. Said wheels, which are arranged on said transversal beam even more apart from each other as e.g. the front wheels of the tractor, may have a negative impact with respect to maneuverability of the tractor, since among others due to larger radius of wheel path also a broader path is required. On the other hand normally the overturning stability may be essentially improved. As mentioned, each of said wheels is embedded on the transversal beam and may be freely rotated around the vertical axis, by which said embedding is eccentric, which means that such wheel may during the movement be freely pivoted into a desired direction, since the horizontal axis, around which the wheel is rotated, is positioned at a sufficient distance apart from the vertical axis, in which the wheel is pivotally embedded. However, when heavy loads are transferred along a rough terrain and each load is held at a certain distance apart from the soil, then each inclination with respect to the horizontal plane may result in movement of the load in the transversal direction. Since the load is placed on the lifting device, the forces are transferred from the load towards the lifting device, which is capable to takeover such forces, but the wheels are unable to withstand the forces until acting in the transversal direction. In such situation all these forces are then transferred to the front portion of the tractor, which therefore easily results in appropriate change of the driving direction and loss of control. This may also happen whenever the wheels of the chassis come into contact with an obstacle or an inclined surface, upon which the front portion of the tractor is practically hoisted, by which the contact between the front wheels of the tractor and the ground may actually be completely eliminated.

The present invention relates to a lifting and manipulating device for tractors, wherein such device comprises at least approximately transversal beam, to which two wheels are attached and each of said wheels may be rotated around its horizontal axis, which extends through the belonging bifurcated shaft, and may furthermore at the same time also be rotated together with said bifurcated shaft around the vertical axis. Such device further comprises appropriate pivot joints, which are adapted for establishing a connection among said transversal beam and corresponding levers and a hydraulic rod of the manipulating mechanism on the rear portion of a tractor. Still further such device comprises an at least in approximately vertical direction displaceable lifting assembly, which is connected to said transversal beam via a corresponding bearing structure and to which then a desired lifting or manipulating accessory or any other operational attachment may be mounted.

According to the invention said lifting assembly is mounted on a single centrally arranged and telescopically extendable mast, which is firmly connected with the transversal beam, which is adapted to be attached to the tractor and equipped with such wheels, by which the rotation around the vertical axis and/or the horizontal axis may either be enabled or when desired also at least partially or completely disabled.

Said telescopically extendable mast consists at least of an internal tubular member, which is firmly connected with said transversal beam and within which a hydraulic cylinder is placed, as well as of an external tubular member, in which said internal tubular member is suitable inserted and which is also connected with said cylinder. In this, said lifting assembly, which is displaceable along said external tubular member, comprises at least two supporting rollers, which are arranged in contact with the opposite side surfaces of said external tubular member, and is moreover connected with the first end section of a flexible traction member, which extends over a supporting wheel, which is arranged in the top portion of said mast, and the second other end section of which is attached to the internal tubular member of the mast, wherein said flexible traction member is in particular selected from the group, which includes ropes, chains and belts.

Furthermore, each corresponding manipulating or operational accessory may be attached to the lifting assembly either directly or indirectly via a mounting plate, which is then attached to said lifting assembly. Said mounting plate is then firmly but detachably connected with the lifting assembly and is preferably at the same time allowed to be at least in a certain extent i.e. at a certain angle pivoted around the vertical axis. In this lastly mentioned embodiment the mounting plate is attached to the lifting assembly by means of a pin having a vertically extending longitudinal axis, wherein a control member is foreseen, which is connected both to the mounting plate and also to the lifting assembly, while said control member is preferably a hydraulic cylinder, which is at the one end pivotally connected to the mounting plate and on the other end also pivotally to the lifting assembly.

Still further, each wheel in such a device is furnished with a brake, which either allows free rotation of said wheel around the horizontal axis thereof or - when desired - also partially or completely prevents said wheel from being rotated around said horizontal axis. In addition to that, each wheel is rotationally around the vertical axis embedded within a corresponding bearing means available on the transversal beam, by which an engaging means, preferably a pin, is foreseen within each bearing member, by means of which a free rotation of said wheel around the vertical axis may be either partially or in particular completely eliminated.

In a further embodiment of invention each wheel is rotationally around the horizontal axis embedded in the belonging bifurcated shaft, which is rotationally around the vertical axis and moreover also pivotally around another horizontal axle embedded within a corresponding bearing member, by which said axle is available within the area of said bearing member and said bifurcated shaft is furnished in the adjacency of the bottom surface of said bearing member with two apart from each other inclined surfaces, which are arranged on the opposite sides of said vertical axis, so that each time alternatively just one of said surfaces of said bifurcated shaft is brought in contact with the adjacent bottom surface of the bearing member.

Accordingly, positioning of the rotation axis of each corresponding wheel, which extends through the belonging bifurcated shaft, with regard to direction of actual movement behind the vertical axis, around which said bifurcated shaft is rotated, is achieved either by means of rotation of said bifurcated shaft around the belonging vertical axis, or (or also) by means of pivoting said bifurcated shaft around the horizontal axle, by which instead of each existing contact between the actual inclined surface and the bottom surface of the bearing member another contact is established between the opposite inclined surface and the bottom surface of the bearing member, or vice versa.

Finally, the device according to the invention may also be characterized by at least one fork or mixing through or bale gripping accessory or a similar accessory for gripping uniform loads or even a hook, which is is attached to the lifting assembly either directly or indirectly via appropriate mounting plate, which is either firmly or pivotally around the vertical axis attached thereto.

Now the invention will be explained in more detail on the basis of several embodiments, which are shown in the attached drawings, in which

Fig. 1 is a top view of the first embodiment of a lifting and manipulating device for tractors, which is presented in its mounted state; Fig. 2 is a rear view of said first embodiment of a lifting and manipulating device for tractors, again shown in its mounted state; Fig. 3 is a top view of one of the supporting wheels; Fig. 4 is a left side view of said wheel according to Fig. 3; Fig. 5 is a cross-section of said wheel in the plane V - V according to Fig. 4; Fig. 6 is a further embodiment of a wheel, which belongs to said device according to the invention;

Fig. 7 is a side view of said wheel according to Fig. 6; Fig. 8 is a cross-section of said wheel along the plane VIII - VIII according to

Fig. 6; Fig. 9 is a schematically presented top view of a device according to Figs 1 and

2 together with a wheel according to Figs 3 - 5; Fig. 10 is a cross-section of the first embodiment of the device according to Figs

1 - 6 in the plane IX - IX according to Fig. 9; Fig. 11 is a cross-section of the second embodiment of the device according to

Figs 1 - 6 in the plane IX - IX according to Fig. 9; Fig. 12 is a top view of the second embodiment of the device according to the invention in its mounted state; Fig. 13 is a top view of the third embodiment of the device according to the invention in its mounted state; Fig. 14 is a top view of the embodiment according to Fig, 13 in a detached state and with surmounted trough or digging bucket; Fig. 15 is a top view of the fourth embodiment of a device according to the invention in its mounted state; and Fig. 16 is a top view of the fifth embodiment of a device according to the invention in its mounted state.

A lifting and manipulating device for tractors essentially consists of a telescopic mast 1, on which a vertically movable lifting assembly 13 is mounted and, which is firmly connected with a transversal beam 8, on which on the one hand two wheels 5', 5" are mounted and on which on the other hand also appropriate pivot joints 83, 84 are foreseen, which serve for the purposes of establishing a detachable connection of said beam 8 with appropriate hoisting levers 3 and a hydraulic rod 4 of the manipulating mechanism of a tractor 20, which may also be furnished with a balancing weight 2 for the purposes of compensation of weight of the device and/or the load.

Each of said wheels 5', 5" is generally in a freely pivoting manner embedded by means of a bifurcated shaft 56 within an adequate bearing means 85 on the transversal beam 8 and may be therefore pivoted around its vertical axis 50 (Fig. 4) and moreover at the same time also turned around its horizontal axis 51. Said axis 50 on the beam 8, around which said wheel 5', 5" is turned, normally extends in some offset position with respect to said wheel 5', 5", so that when rolled along the soil due to the existing resistance each wheel 5', 5" stays behind, wherein with respect to Fig. 3 by moving towards the right it is turned into a position, which is shown in Fig. 3, while by moving thereof towards the left it is then turned around the axis 50 into a mirrored opposite position with respect to said Fig. 3.

According to the invention each wheel 5, 5" is equipped in the area of said bearing means 85 with an engaging means 58, which is intended to hinder i.e. to eliminate partially or completely said free rotation of the wheel 5', 5" around the vertical axis 50. In the shown embodiment said engaging means 58 is a pin, which may either block rotation of the wheel 5', 5" around the axis 50 in its inserted state, or may also allow said rotation in its detached state.

Furthermore, each wheel 5', 5" is equipped with a brake unit 52, preferably on the basis of a brake drum as shown in Fig. 5. In the embodiment according to Fig. 6 - 8 the wheel 5' is allowed to rotate around the vertical axis 50 and is embedded within the bearing means 85, while at the same time it is also allowed to rotate around the horizontal axis 51, which extends through said bifurcated shaft 56, wherein also said bifurcated shaft 56 is hinged on the belonging horizontal axle 53, which extends parallel to said axis 51 of rotation of the wheel 5' with respect to said bifurcated shaft 56. In this, said bifurcated shaft 56 is equipped with inclined surfaces 54', 54" in the area of possible contact with the bottom surface 85' of said bearing member 85, which are available on both opposite sides with respect to said vertical axis 50 and adapted to allow alternatively one or another of said inclined surfaces 54', 54" to come into contact with said bottom surface 85' of the bearing member 85. Consequently, said bifurcated shaft 56 may be pivoted around the horizontal axle 53 with respect to said bearing member 86 from one position, where the inclined surface 54' is in contact with the bottom surface 85' of the bearing member 85 (Fig. 6), into another position, where the opposite inclined surface 54" is in contact with said bottom surface 85' of the bearing member 85, or vice versa. In the sense of Fig. 6 this naturally means, that during the rolling towards the left the axis 51 of the wheel 5' is positioned in front of the axle 53 of the bifurcated shaft 56 as well as the vertical axis 50, even such a case, when said shaft 56 together with the belonging wheel 5' could of any reason not be turned around the vertical axis 50, since the bifurcated shaft 56 is then pivoted from the current position, where the inclined surface 54' is in contact with the bottom surface 85' of the bearing member 85 into another position, in which the opposite inclined surface 54" is in contact with said bottom surface 85' of the bearing member 85, upon which the axis 51' of the wheel 5' becomes positioned behind the axle 53 and the axis 50 of the bifurcated shaft 54 again. Those skilled in the art should understand, that the inclination of said surfaces 54', 54" may be determined on the basis of each desired eccentricity of position of the wheel 5', namely on the basis of each desired horizontal distance between the vertical axis 50 and the horizontal axis 51 of the wheel 5'.

As already mentioned said telescopic mast 1 is firmly connected with said transversal beam 8 and extends essentially in the vertical direction and is moreover arranged in approximately central position between both wheels 5', 5", when observed in a transversal direction of the device. Said mast 1 consists of at least two tubular members 11, 12, which are inserted each into another, by which for the purposes of simplifying a further explanation exclusively an embodiment will be discussed, which is shown in Fig 9 and by which an internal tubular member 11 is suitably inserted into an external tubular member 12 and at the same time firmly connected with the transversal beam 8. Said external tubular member 12 may accordingly be displaced along said internal tubular member 11 by means of a hydraulic cylinder 14, which is mounted within the internal tubular member 11.

Such a concept of the mast 1 , which consist of said external tubular member 11 and internal tubular member 12 inserted therein excels in much higher bending and torsion stiffness in comparison with known devices, where various frames consisting of U rolled steel or similar elements are used. In addition to that, such mast allows to a driver much better visibility towards the manipulating area as e.g. said frames of then known devices.

A lifting assembly 13 is mounted onto the external tubular member of the mast 1 in order to be displaced along the external tubular member 12 of the mast 1, namely along the external surface thereof. For such purposes said assembly 13 is furnished with a desired number of appropriately arranged rollers 15', 15", which enable at the one hand desired movements of the assembly 13 along the tubular member 12, and on the other hand also a desired transfer of loadings from said assembly 13 towards the external tubular member 12 and herewith to a mast 1 and indirectly also to said transversal beam 8. In this particular embodiment (Fig. 9) two rollers 15', 15" are foreseen, which are arranged on opposite sides of the external tubular member 12 of the telescopic mast 1. Said lifting assembly 13 is driven along the external tubular member 12 of the mast 1 by means of a flexible traction member 10, which extends over the supporting wheel 9, which is available in the top area of said mast 1, wherein the first end section 101 of said traction member is connected with the lifting assembly 13 and the residual end section 102 is attached to the internal tubular member 11 within the mast 1. In this embodiment said traction member 10 is a stud chain, but in generally also any other chain, a rope or a belt may be used for this purpose.

Said lifting assembly 13 preferably includes a mounting plate 7, to which various manipulating accessories or devices may be attached, which will be subsequently explained in more detail. Said mounting plate 7 is either firmly connected with the lifting assembly 13 (Fig. 10) or may also be pivotally connected i.e. hinged thereto (Fig. 11) in order to be pivoted around the vertical axis. In the embodiment according to Fig. 8 said plate 7 is by means of adequate pin 70 at least in a determined extent i.e. at a desired angle pivoted around the vertical axis, which corresponds to the longitudinal axis of said pin 70, and is at the same time via an appropriate control member 71 - i.e. a hydraulic cylinder in this particular embodiment - connected with said lifting assembly, which is able to move along the mast 1, namely along the external tubular member 12 thereof. In this, said control member 71 or a hydraulic cylinder in this particular embodiment is hinged to the mounting plate 7 at the one end and adequately hinged to the lifting assembly 13 at the one end. The first embodiment according to Figs 1 to 11 is intended to be used as a fork lift and for such purposes includes appropriate fork 16 attached to said mounting plate 7. The first embodiment according to Figs 1 to 7 enables performing all required functioning steps like by ordinary fork lifts, but the pivotally connection between the mounting plate 7 and the lifting assembly 13 should normally lead to a still further improvement of maneuverability especially in the stage of approaching the load during the loading operation, or also in the stage of removing said fork 16 apart from the load during unloading operations.

A further embodiment is shown in Fig. 9, where a trough 17, is connected in a detachable manner to said lifting assembly 13, wherein such trough is preferably adapted for mixing mortar or the like.

A still further embodiment is shown in Figs. 10 and 11, in which said lifting assembly 13 is furnished with a pivotally attached mounting plate 7 and is adapted to receive various accessories like a digging bucket, a fork, a bale gripping device or the like.

Another embodiment is visible in Fig. 12, where a bale gripping device 18 or any other accessor}^ for gripping uniform loads is mounted in a detachable manner to said lifting assembly 13.

Another embodiment is visible in Fig. 13, where a hook 19 is mounted in a detachable manner to said lifting assembly 13.

All these embodiments refer to an improved lifting and manipulating device, which is adapted for being attached to each existing manipulating mechanism 3, 4 of a tractor 20, which normally stays at disposal for the purposes of attaching and controlling any other commonly known accessories. In this, said device enables receiving and gripping and then lifting appropriate loads in the vertical direction as well as any other desired manipulation of load in at least essentially horizontal direction i.e. essentially parallel with respect to the ground.

Thanks to a desired construction concept of said wheels 5', 5", which are furnished with appropriate brake 52, which is capable either to slow down or even to stop turning said wheels 5', 5" around the horizontal axis 51, and moreover simultaneously also to said engaging means 58, by which also the turning of wheels 5', 5" around the vertical axis 50 may optionally be eliminated, the device may naturally excel in essentially improved maneuverability as well as driving and stability characteristics of the tractor 20 furnished with such a device including the load during the use thereof. In addition to that, when bearing in mind said mast 1 it is also obvious, that such mast 1 may also lead to essential benefits from the point of view of a person, who controls the tractor 20 and/or the device according to the invention, since the visibility towards the actual manipulating area still remains quite perfect, which is however essentially important with respect to both steering the tractor 20 and manipulating of each corresponding load.

Claims

PATENT CLAIMS

1. Lifting and manipulating device for tractors, comprising at least approximately transversal beam (8), to which two wheels (5', 5") are attached, each of them may be rotated around its horizontal axis (51) extending through each belonging bifurcated shaft (56) and at the same time together with said bifurcated shaft (56) also around the vertical axis (50), and further comprising appropriate pivot joints (83, 84), which are adapted for establishing a connection among said transversal beam (8) and corresponding levers (3) and hydraulic rod (4) of the manipulating mechanism on the rear portion of a tractor (20), and still further comprising an at least in approximately vertical direction displaceable lifting assembly (13), which is connected to said transversal beam (8) via a corresponding bearing structure (1) and to which then a desired lifting or manipulating accessory or any other operational attachment (16, 17, 18, 19) may be mounted, characterized in that said lifting assembly (13) is mounted on a single centrally arranged and telescopically extendable mast (1), which is firmly connected with the transversal beam (8), which is adapted to be attached to the tractor (20) and equipped with such wheels (5', 5"), by which the rotation around the vertical axis (50) and/or the horizontal axis (51) may either be enabled or when desired also at least partially or completely disabled.

2. Device according to Claim 1, characterized in that said telescopically extendable mast (1) consists at least of an internal tubular member (11), which is firmly connected with said transversal beam (8) and within which a hydraulic cylinder (14) is placed, as well as of an external tubular member (12), in which said internal tubular member (11) is suitable inserted and which is also connected with said cylinder (14).

3. Device according to Claim 1 or 2, characterized in that the lifting assembly (13), which is displaceable along said external tubular member (12), comprises at least two supporting rollers (15', 15") arranged in contact with the opposite side surfaces of said external tubular member (12) and is moreover connected with the first end section (101) of a flexible traction member (10), which extends over a supporting wheel (9) arranged in the top portion of said mast (1) and the second other end section (102) of which is attached to the internal tubular member (11) of the mast (1).

4. Device according to one of Claims 1 to 3, characterized in that each corresponding manipulating or operational accessory (16, 17, 18, 19) is attached directly to the lifting assembly (13).

5. Device according to one of Claims 1 to 3, characterized in that each corresponding manipulating or operational accessory (16, 17, 18, 19) is attached to a mounting plate (7), which is attached to the lifting assembly (13).

6. Device according to Claim 5, characterized in that the mounting plate (7) is firmly but detachably connected with the lifting assembly (13).

7. Device according to Claim 5, characterized in that the mounting plate (7) is detachably connected with the lifting assembly (13) and is at the same time allowed to be at least in a certain extent i.e. at a certain angle pivoted around the vertical axis.

8. Device according to Claim 7, characterized in that the mounting plate (7) is attached to the lifting assembly (13) by means of a pin (70) having a vertically extending longitudinal axis, and that a control member (71) is foreseen, which is connected both to the mounting plate (7) and also to the lifting assembly (13).

9. Device according to Claim 8, characterized in that said control member (71) is a hydraulic cylinder, which is at the one end pivotally connected to the mounting plate (7) and on the other end also pivotally to the lifting assembly (13).

10. Device according to one of Claims 1 to 9, characterized in that each wheel (5', 5") is furnished with a brake (52), which either allows free rotation of said wheel (5', 5") around the horizontal axis (51) thereof or when desired also partially or completely prevents said wheel (5', 5") from being rotated around said horizontal axis (51).

11. Device according to one of Claims 1 to 10, characterized in that each wheel (5', 5") is rotationally around the vertical axis (50) embedded within a corresponding bearing means (85) available on the transversal beam (8), by which an engaging means (58) is foreseen within each bearing member (85), by means of which a free rotation of said wheel (5', 5") around the vertical axis (50) may be either partially or in particular completely eliminated.

12. Device according to Claim 11, characterized in that said engaging means (58) is a pin.

13. Device according to one of Claims 1 - 10, characterized in that each wheel (5', 5") is rotationally around the horizontal axis (51) embedded in the belonging bifurcated shaft (56), which is rotationally around the vertical axis (50) and moreover also pivotally around another horizontal axle (53) embedded within a corresponding bearing member (85), by which said axle (53) is available within the area of said bearing member (85) and said bifurcated shaft (56) is furnished in the adjacency of the bottom surface (85') of said bearing member (85) with two apart from each other inclined surfaces (54', 54'), which are arranged on the opposite sides of said vertical axis (50), so that each time alternatively just one of said surfaces (54', 54") of said bifurcated shaft (56) is brought in contact with the adjacent bottom surface (85') of the bearing member (85).

14. Device according to Claim 13, characterized in that positioning of the rotation axis (51) of each corresponding wheel (5', 5"), which extends through the belonging bifurcated shaft (56), with regard to direction of actual movement behind the vertical axis (50), around which said bifurcated shaft (56) is rotated, is achieved either by means of rotation of said bifurcated shaft (56) around the belonging vertical axis (50), or (or also) by means of pivoting said bifurcated shaft (56) around the horizontal axle (53), by which instead of each existing contact between the actual inclined surface (54') and the bottom surface (85') of the bearing member (85) another contact is established between the opposite inclined surface (54") and the bottom surface (85') of the bearing member (85), or vice versa.

15. Device according to one of Claims 1 to 14, characterized in that at least one fork (16) is attached to the lifting assembly (13) either directly or indirectly via appropriate mounting plate (J), which is either firmly or pivotally around the vertical axis attached thereto.

16. Device according to one of Claims 1 to 14, characterized in that at least one mixing trough (17) is attached to the lifting assembly (13) either directly or indirectly via appropriate mounting plate (7), which is either firmly or pivotally around the vertical axis attached thereto.

17. Device according to one of Claims 1 to 14, characterized in that at least one bale gripping accessory (18) or a similar accessory for gripping uniform loads is attached to the lifting assembly (13) either directly or indirectly via appropriate mounting plate (7), which is either firmly or pivotally around the vertical axis attached thereto.

18. Device according to one of Claims 1 to 14, characterized in that at least one hook (19) is attached to the lifting assembly (13) either directly or indirectly via appropriate mounting plate (7), which is either firmly or pivotally around the vertical axis attached thereto.

19. Device according to Claim 3, characterized in that said flexible traction member (10) is selected from the group, which includes ropes, chains and belts.