WO2010028649A1

WO2010028649A1 - Machine

Info

Publication number: WO2010028649A1
Application number: PCT/DK2009/050231
Authority: WO
Inventors: Hans Otto Lynge Pedersen
Original assignee: Lmb Andkær Smedie (Lynge Maskinbyg) V/ Hans Otto L Pedersen
Priority date: 2008-09-12
Filing date: 2009-09-10
Publication date: 2010-03-18
Also published as: DK176929B1; DK200801280A

Abstract

A machine (1), preferably an excavator, a felling machine, a brush cutter or a demolition machine, including: - an undercarriage (2) including a frame (3); - propulsion means (4) at each side of a centre plane (5) through the frame (3), the centre plane (5) being parallel with the driving direction of the machine; - a top section (6) arranged above the undercarriage (2) and including a driver position (7); - a tilting arrangement (9) disposed between the undercarriage (2) and the top section (6) for tilting the top section (6) in relation to the undercarriage (2) about a tilt axis (9) through the machine (1); - at least one telescopic arm (10) at each side of the centre plane (5), the telescopic arms (10) being mounted between the frame (3) and the propulsion means (4) for changing the distance between the propulsion means (4); wherein the tilt axis (9) coincides with the centre plane (5) and the telescopic arms (10) may be displaced independently of each other.

Description

MACHINE

Field of the Invention

The present invention concerns a machine, preferably an excavator, a felling machine, a brush cutter or a demolition machine, including: - an undercarriage including a frame;

- propulsion means at each side of a centre plane through the frame, the centre plane being parallel with the driving direction of the machine;

- a top section arranged above the undercarriage and including a driver position;

- a tilting arrangement disposed between the undercarriage and the top section for tilting the top section in relation to the undercarriage about a tilt axis through the machine; and

- at least one telescopic arm at each side of the centre plane, the telescopic arms being mounted between the frame and the propulsion means for changing the distance between the propulsion means.

In the present application, by tilt axis is meant an axis which is parallel with the driving direction of the undercarriage and which extends through at least part of the machine.

In the present application, by centre plane is meant a plane largely through the centre of the frame, the plane being parallel with the driving direction of the undercarriage. The top section may also have a centre plane.

In the present invention, by transverse axis is meant an axis extending through the frame and which is orthogonal to the centre plane through the frame.

Background of the Invention

In connection with using various self-propelled machines with a position for a driver, such as excavators, felling machines, brush cutters, demolition machines, it often happens that it is necessary to operate in hard-to-access areas on a sloping ground, frequently with deviating carrying capacity of the ground. This gives rise to several disadvantages. - The work becomes less comfortable for the driver of the machine as the driver is influenced by a gravity-induced force acting in lateral direction. This force will urge the driver to slide out of the seat. The driver thus has to counteract the force all the time in order to stay in the seat while working on a sloping ground. - For a machine with a jib carrying a work tool, it will be very difficult to operate in vertical direction when the machine stands on sloping ground; this is necessary for e.g. an excavator working close to the side of an obstacle, such as a building. Unless the machine is completely horizontal it will not be possible to dig a vertical trench at the side of the building when the machine stands with an inclination. - In the same way as the driver, the machine will be influenced by a force acting in lateral direction when working on sloping ground. The force of gravity acts in the centre of gravity in vertical direction, and therefore this lateral force arises which will tend to overturn the machine when driving or standing on sloping ground. Thus there will be a limit to the slope of the ground on which it drives without the machine overturning. If the ground has deviating carrying capacity, where the carrying capacity is the least at the bottom of the slope, the machine will reach this limit at a lesser slope angle.

There exists an excavator with a hinge arrangement for righting the top of the excavator relative to an undercarriage including a frame. This excavator has a hinge arrangement which is disposed at the top side of the undercarriage at one side of a centre plane through a frame. The excavator is provided with an actuator for tilting to the opposite side of the centre plane. The excavator may thus only be tilted to one side.

The same mini-excavator is provided with caterpillar tracks that may be displaced laterally such that the track or wheel gauge is increased by about 30%. This enhances the stability of the mini-excavator.

Object of the Invention

It is the object of the invention to indicate an undercarriage for a machine which enables righting to both sides of a top section disposed upon the undercarriage to a position, where a driver position at the top section can be righted to an approximately horizontal position when the machine drives along a base which is not horizontal. The machine is to be adapted for driving on even steep slopes giving the machine a strong lateral inclination without danger of the machine overturning.

Description of the Invention

This is achieved according to the present invention with a machine of the kind mentioned in the introduction, which is peculiar in that that the tilt axis coincides with the centre plane and that the telescopic arms can be displaced independently of each other.

Hereby is achieved that the machine can be righted to both sides as the tilting arrangement by tilting about the tilt axis disposed in the centre plane may be provided a deflection which is of the same size to both sides. This is on the condition that there are no mechanical parts of the machine that limit such a deflection.

The machine will be designed such that there is a spacing between the underside of the top section and the top side of the frame and the propulsion means. This spacing determines how large an angle the machine can be tilted, and thereby how much slope the ground may have.

Moreover, it is achieved that the centre of gravity is moved in a direction counteracting the lateral forces induced by the gravitational force when driving on a sloping ground.

Besides, the tilting about the tilt axis located in the centre plane ensures that the centre of gravity may be kept within the support area of the propulsion means when the top section is righted in relation to the sloping ground. The top section may advantageously be disposed such that the centre of gravity of the top section is located largely vertically above the tilt axis. This entails that the forces acting on the top section are the same by deflection to either side.

By the invention is thus achieved a comfortable driving position for the driver while at the same time it is adapted to counteract the forces seeking to overturn the machine by moving the centre of gravity. Moreover, by the individual displacement of the telescopic arms it is achieved that the weight distribution between the propulsion means at each side of the centre plane can be controlled. If the ground at one side is softer than the ground on the other side, the weight may be distributed such that the propulsion means supported by the relatively harder ground carries a greater part of the weight of the machine.

In an embodiment of the invention, the telescopic arms may be displaced such that the wheel or track gauge of the undercarriage may be increased by 70%.

The telescopic arms at each side may displace the propulsion means independently of each other such that the frame is not necessarily disposed midways between the propulsion means. This makes it possible to distribute the weight variably between the two sides, e.g. from 40/60 via 50/50 to 60/40. This is advantageous when the ground has deviating carrying capacity as the weight may be distributed so that the propulsion means under which the ground has the greatest carrying capacity absorbs the greater share of the weight.

The machine finds application in many different contexts where it is necessary to drive on ground which is sloping. Examples of applications may be as follows:

- For an excavator or mini-excavator used for working in ditches or along buildings. Such a machine with a righted top section may move a jib or an arm in vertical direction and thereby dig vertical trenches. That the machine may be righted to either side provides flexibility with regard to which side the ground is sloping.

- For a brush cutter, excavator or cutting machine operating in ditches along motorways, it being the area between two opposite carriageways or at the waysides. In such areas, lampposts, road signs or other obstacles are often placed at the bottom of the ditches. Since the space is often limited, it is a great advantage that the driver cab can be righted as is will not project outside the outer limits of the propulsion means, and thereby one will not risk driving into the obstacles with the cab, while at the same time it is possible to pass close by the obstacle on the sloping ground because the cab is situated within the outer limits of the undercarriage. Besides, the ground at the bottom of the ditches will often be soft as water is often accumulated here. The machine may compensate for this by the telescopic arms as the telescopic arm at the side closest to the bottom of the ditch is displaced to an extreme position, while the telescopic arm at the side farthest from the bottom of the ditch is displaced towards an inner position. The propulsion means at the side closest to the bottom of the ditch will thereby carry a lesser part of the weight, and the machine may operate with better support and thereby greater safety.

- For a brush cutter or felling machine that operates in the hard-to-access terrain along and on an the side of a railway cutting. The side of a railway cutting has a steep inclination with the ground having deviating carrying capacity. The machine enables clearing the area while keeping the railway tracks free as the machine may operate directly on the side of the railway cutting at the required safety distance from the railway tracks. The machine thus enables clearing the area from growth without disturbing the train service, implying a great increase in the clearing capacity being the distance along the rails which can be cleared per day. The ground on the slope will typically be more unstable closer to the top of the slope due to loose broken stones. The machine may compensate for this by the telescopic arms as the telescopic arm closest to the bottom of the slope is displaced to an innermost position, and the telescopic arm closest to the top of the slope is displaced to an outermost position. The propulsion means closest to the bottom of the slope may thus carry a greater part of the weight of the machine than the propulsion means closer to the top of the slope. The machine may thereby operate on the slope with greater safety.

- For a tractor operating on sloping fields. The righting to either side is here a great advantage, for example in connection with ploughing or harrowing when driving back and forth along the slope.

- For logging machines operating in forests where the terrain is difficult to access, is sloping, causing shifting from side to side, and with deviating carrying capacity.

The above examples are not to be considered as limiting the possible applications as the machine may be provided with different top sections depending on the application. According to a further embodiment, the machine according to the invention is peculiar in that the tilting axis is optionally situated largely at the lowest point of the frame or at a point under the frame.

The deflection of the top section is hereby maximised when it is tilted. Therefore, this provides the greatest displacement of the centre of gravity that may possibly be achieved by a given design. It is still implied that the machine is designed such that the distance between the underside of the top section and the top side of the undercarriage is sufficient to enable the required deflection.

If the tilt axis is disposed under the frame, it is possible that the centre of gravity of the top section may be displaced to a point close to the lateral extension of the propulsion means, thereby providing the possibility of operating on a ground with a steep slope.

According to a further embodiment, the machine according to the invention is peculiar in that the telescopic arms are arranged at a downwardly directed angle.

Hereby is achieved the possibility of a larger deflection of the top section, and thereby a greater righting of the top section. When the undercarriage is driven in on a sloping ground, righting is commenced and thereby tilting or weight displacement of the top section. As mentioned above, the righting angle will be limited by the distance between the top side of the undercarriage including the propulsion means and the underside of the top section. By a downwardly directed angle of the telescopic arms corresponding to the angle with which the top section can be righted relative to the ground, the telescopic arms may variably be displaced without risking that any part of the machine will strike another part of the machine, even during the greatest righting.

With a maximally angled top section relative to the undercarriage, the upper telescopic arm will thus be displaced in parallel with the underside of the top section. The righting angle thus has no influence on the gauge.

The angle of the telescopic arms of a machine used as excavator, mini-excavator or felling machine will typically be in the range 20° to 35°, preferably 25°, which has appeared to be an optimal compromise between maximum deflection of the top section and thereby maximum slope of the ground in relation to the total height of the machine. By machines for other purposes, the optimal range of the downwardly directed angle of the telescopic arms may be a different one.

According to a further embodiment, the machine according to the invention is peculiar in that it includes a rotary mechanism which is disposed between the tilting arrangement and the top section for rotating the top section about a largely vertical axis through the top section.

The ability to work at all sides of the machine with a tool is hereby achieved. The righting of the machine enabled by the invention produces a horizontal and stable platform for the top section. The disposition of the rotary mechanism upon the tilt arrangement entails that rotation occurs about a vertical axis. When the machine is righted along a sloping surface, the tool may thus be moved up and down in vertical direction, which for the greater part is a requirement to contractor's machines.

The rotary mechanism may be designed such that it completely or partially enables 360° rotation in both directions. By machines where the top sections include an engine compartment, the rotary mechanism is to include a power transmission to the undercarriage. This power transmission may be mechanical, pneumatic, electric or hydraulic as the propulsion means and possible other consumers on the undercarriage, such as the telescopic arms, need such a power transmission in order to operate.

The rotary mechanism will typically be a yaw ring.

According to a further embodiment, the machine according to the invention is peculiar in that the propulsion means are chosen optionally among caterpillar tracks or wheels.

The choice of propulsion means is based on a compromise between i.a. complexity and allowed surface pressure. The footprint of a caterpillar track is greater than that of a wheel with the same height, but wheels provide a less complicated rebuilding of the machine combined with lower price and a large assortment for various purposes. The caterpillar track is chosen when a low surface pressure is desirable. This may be the case when the machine operates on soft ground where there is a risk that the machine will sink down into the ground and get stuck, or if disturbing the ground the least possible is desired. Caterpillar tracks include belts as well as chains of rubber or metal.

Wheels are selected when there is no requirement of low surface pressure or when low complexity is a predominant factor. Besides, wheels provide the possibility of attaining higher speeds than by using caterpillar tracks.

Caterpillar tracks and wheels may be designed so that they provide a good grip in the ground.

According to a further embodiment, the machine according to the invention is peculiar in that a first hinge means is disposed between the propulsion means and the telescopic arms for pivoting the propulsion means about a longitudinal axis through the propulsion means.

Hereby is achieved that the propulsion means can be angled such that they follow the sloping ground for the best possible support. This is, for example, an advantage in connection with cleaning of drainage canals where the machine has a propulsion means disposed at each side of the canal. The ground for the propulsion means will slope in each their direction, but an individual angular pivoting of the propulsion means at each side will ensure that each propulsion means is supported along its entire width.

Besides, the propulsion means can be turned in such a way that they "bite" or grip firmly in the sloping ground. Here, a propulsion means will intentionally be pivoted such that the part of the propulsion means farthest from the machine will dig itself down into the ground. This method is chosen when there is a risk that the machine will slide sideways down the sloping ground. This may be the case if the ground is smooth, thereby not providing possibility for the propulsion means to get the necessary grip in the ground. The angle by which the propulsion means can be pivoted about the longitudinal axis for a machine used as an excavator, mini-excavator, bush cutter or felling machine is typically in the range -15° to +50°, where 0° is the vertical position of the propulsion means.

According to a further embodiment, the machine according to the invention is peculiar in that the tilting arrangement includes a second hinge means for tilting about the tilt axis.

Hereby is achieved an uncomplicated and strong construction of the undercarriage as the necessary strength of the tilt arrangement easily can be ensured. The hinge means will typically be disposed so that the tilt axis is located at the lowest point of the frame.

According to a further embodiment, the machine according to the invention is peculiar in that the tilting arrangement includes at least one actuator at each side of the centre plane, that each actuator at one end has a fixed angle relative to a first support, that each actuator at its other end is provided with a rotatable connection to a second support, and that the first support and the second support are optionally disposed on the undercarriage or the top section, respectively.

Hereby is achieved that the tilt axis can be moved to a point which is lower than the frame, as by establishing the tilting arrangement by means of actuators one is not limited to a mechanical tilt axis. The tilt axis may furthermore be moved up and down along the centre plane if desired. This can be done by varying the travel of the actuators in relation to each other between the extreme points of the deflection of the top section.

In a particular embodiment of the machine, the tilting arrangement includes four actuators. Hereby it becomes possible to right the top section to horizontal position in the case that the ground slopes in directions that are not parallel with the tilt axis. The tilt axis is not coincident with the centre plane in this case. According to a further embodiment, the machine according to the invention is peculiar in that the tilting arrangement, the telescopic arms, the rotary mechanism, the first hinge means and the second hinge means are optionally provided with at least one actuator which is optionally selected among hydraulic, electric or pneumatic actuators.

The choice of actuator type depends on several factors.

Hydraulic actuators would be the preferred choice since there exist a large assortment of components and great forces may be attained even by small actuators, but in connection with maintenance of the hydraulic components there may be a risk of contamination to the environment. Hydraulic components also require relatively large hoses that take up some space on the machine.

It may be expected that in the future we will se a greater propagation of electric actuators as the demand for environment- friendly machines rises. In connection with electrically powered machines it would of course also be natural to choose electric actuators. The current is conducted to the actuators through cables which do not demand as much space. In addition, it is possible to transmit the current through slip rings so that a possible rotary mechanism does not have to allow for a more complicated power transmission.

Pneumatic actuators are chosen when particular environmental considerations are to be taken, as maintenance and replacement of actuators are not connected with environmentally hazardous hydraulic oil. A given pneumatic actuator may, however, not transmit as large forces as those produced by a hydraulic actuator of the same size.

According to a further embodiment, the machine according to the invention is peculiar in that the tilting arrangement, the telescopic arms, the rotary mechanism, and the hinge means are optionally provided with at least one locking arrangement which is optionally selected among mechanical locking, hydraulic locking, electric locking or pneumatic locking.. The machine will typically be provided with a combination of several of the above types of locking.

By hydraulic and pneumatic locking is meant that respective hydraulic and pneumatic circuits are designed such that valves shut off the individual actuators so that they cannot be moved.

By electric locking is meant a short-circuiting of the actuator so that it cannot move.

In a particular embodiment of the invention, the tilting arrangement is provided with a combination of mechanical and hydraulic locking. The tilting arrangement is provided with a brake disc with a brake calliper connected to the hydraulic system. Besides, the hydraulic system has a valve design that may block the actuator in the tilting arrangement. The latter locking arrangement is dimensioned so that it can retain the top section alone by itself. When the tilting arrangement is in use, the actuator of the tilting arrangement is pressurised and the brake calliper is relieved so that it opens and the top section is tilted. When the top section has reached the desired position, the tilting arrangement is switched off. The actuator of the tilting arrangement is shut off. Via an accumulator, the pressure is built up again in the brake calliper which squeezes around the brake disc, thereby locking the top section in the desired position.

Description of the Drawing

The invention will now be explained more closely with reference to the accompanying drawing, where:

Fig. 1 shows a machine in an initial position as seen from behind;

Fig. 2 shows a machine with a telescopic arm at one side in an outermost position and a telescopic arm at the other side in an innermost position; Fig. 3 shows a machine with the telescopic arms on both sides in an outermost position; Fig. 4 shows a machine with the telescopic arms on both sides in an outermost position and the hinge means of the propulsion means in an outermost position; Fig. 5 shows a machine operating on a sloping ground with the greater part of the weight put on the upper propulsion means; Fig. 6 shows a machine operating on a sloping ground with the greater part of the weight put on the lower propulsion means; and Fig. 7 shows a machine with a different embodiment of the tilting arrangement.

In the explanation of the Figures, identical or corresponding elements will be provided with the same designations in different Figures. Therefore, no explanation of all details will be given in connection with each single Figure/embodiment.

Detailed Description of the Invention

Figs. 1-7 show different views and illustrations of a machine 1 according to the invention. The machine 1 includes an undercarriage 2 and a top section 6 which is arranged over the undercarriage 2. Moreover, the machine 1 includes a tilting arrangement 8 which is disposed between the undercarriage 2 and the top section 6.

The undercarriage 2 includes a frame 3 and propulsion means 4 at each side of a centre plane 5 through the frame 3. The centre plane 5 is parallel with the driving direction of the machine and vertical in an initial position of the machine 1 when standing on a horizontal base. The propulsion means 4 are connected to the frame 3 with telescopic arms 10 on each side of the centre plane 5. In the shown embodiment, the propulsion means 4 are caterpillar tracks. The propulsion means 4 may be displaced independently of each other by the telescopic arms 10 on each side of the centre plane 5. This enables change of the weight distribution between the propulsion means 4. The shown embodiment provides the option of displacing the telescopic arms 10 which increases the span of the propulsion means 4 by 60%. The telescopic arms 10 have a downwardly directed angle such that the displacement also provides for an increase of the total height of the machine 1. At the same time, the distance between the underside of the top section 6 and the top side of the undercarriage 2, including the telescopic arms 10 and the propulsion means 4, becomes greater when the telescopic arms 10 are displaced towards an outermost position. This provides for greater deflection of the top section 6 without interfering with any part of the undercarriage 2. The connection between the undercarriage 2 and the top section 6 is formed by the tilting arrangement 8. In the shown embodiment, the tilting arrangement 8 is a second hinge means 15 with a tilt axis 9 which is disposed largely at the lowest point of the frame and coinciding with/contained in the centre plane 5. The tilt axis 9 is shown as a point as its direction is orthogonal to the plane of the drawing. In the shown embodiment, a rotary mechanism 11 is disposed between the second hinge means 15 and the top section 6. The rotary mechanism 11 enables rotation of the top section 6 about a largely vertical axis 12 through the top section 6. The vertical axis 12 coincides with the centre plane 15 in an initial position as shown on Fig. 1. The tilting arrangement is provided with a mechanical locking arrangement 21 where the frame is provided with a brake disc 22 and an opposing part of the hinge means 15 is provided with a brake calliper 23 that may retain the top section 6 in the desired position.

In the shown embodiment of the invention, the propulsion means 4 are connected to the telescopic arms 10 by a first hinge means 13. The hinge means 13 enables pivoting the propulsion means 4 about a longitudinal axis 14 through each propulsion means. The longitudinal axis 14 is shown as a point as its direction is orthogonal to the plane of the drawing. In the shown embodiment, the propulsion means can be set in the range -15° to +50° relative to an initial position of 0° as shown on Fig. 1.

The top section 6 comprises a driver position 7. In the shown embodiment, the driver position is enclosed in a driver's cab 19. The driver's cab 19 is shown offset from the centre plane 5, but it may also be disposed at the centre plane 5, depending on what is most suitable. The top section 6 furthermore includes an engine compartment 20 with an engine and a hydraulic pump for driving the propulsion means 4 of the machine, various actuators for the tilting arrangement 8, the telescopic arms 10, the first hinge means 13, the rotary mechanism 11, a possible work tool (not shown) and possible locking arrangements for the said actuators.

The machine in the shown embodiment may operate on ground with a slope from 0° to 45°, but other embodiments of the machine may operate on a ground with an inclination up to 60°. The operations in Figures 1-7 are now explained.

Fig. 1 shows the machine 1 in an initial position where the telescopic arms 10 are in an innermost position and the top section 6 is righted with the tilting arrangement 8 in a intermediate position. This position is used when the ground is horizontal while at the same time greater stability is not required with regard to e.g. lifting capability of a tool. Besides, this position will be used during driving with the machine 1 in general, as the outer dimensions are restricted the most possible in this position.

Fig. 2 shows the machine 1 in a work position where the ground for the propulsion means 4 has different levels. The telescopic arms 10 are displaced such that one telescopic arm 10 is at an innermost position and the other telescopic arm is at an outermost position. The top section is hereby disposed such that the greater part of the weight is carried by one propulsion means.

Fig. 3 shows the machine 1 in a work position where the ground is horizontal but the propulsion means 10 are displaced to their outermost positions. This is used when the machine 1 operates above a ditch over which it can straddle, or when there is required extra stability of the machine 1 in connection with a demand for lifting capability for a tool.

Fig. 4 shows the machine 1 in a work position where the machine 1 operates in a ditch or canal which is too wide for the machine 1 to straddle over. The ground on both sides of the ditch or canal is sloping. The telescopic arms are displaced to their outermost position as in Fig. 3, and the first hinge means 13 are pivoted to an extreme position.

Fig. 5 shows the machine 1 in a work position where the machine 1 operates on a slope. One telescopic arm 10 is displaced to an innermost position with the first hinge means 13 displaced to an angle of about -15°. This displacement of the first hinge means 13 has the purpose of minimising the distance between the underside of the top section 6 and the top side of the propulsion means 4, and to get the propulsion means 4 to "bite" - get a grip - in the ground. One telescopic arm 10 is displaced to an innermost position with the first hinge means 13 displaced to an angle of about +50°. The machine 1 has moved its centre of gravity such that the upper propulsion means 4 absorbs the greater part of the weight of the machine.

Fig. 6 shows the machine 1 in a work position where the machine 1 operates on a slope as on Fig. 5. Here, the machine 1 has moved its centre of gravity such that the lower propulsion means 4 absorbs the greater part of the weight.

If the machine 1 is provided with a jib or arm and a rotary mechanism 11, it may use the jib as support when it is to assume the various work positions. If the machine 1 is to pass a ditch, for example, the machine 1 will support the jib on the opposite side of the ditch and the propulsion means 4 farthest from the jib, while the telescopic arm 10 closest to the jib is displaced to an outer position. Then the jib is lifted such that the machine 10 is supported on both propulsion means 4. The jib is moved to the opposite side and is lowered so that the machine 1 is again supported on the jib and the propulsion means 4 farthest away from the jib. The supporting propulsion means 4 is now a different one. The propulsion means 4 closest to the jib is now displaced to an innermost position, and the jib is lifted such that the machine 1 is again supported on the propulsion means 4. The process is repeated until the machine 1 is in position in the ditch or has passed it. In the same way, the machine can be moved up and down a slope with a steep inclination, such as the side of a railway cutting.

Fig. 7 shows an embodiment of the machine 1 where the tilting arrangement includes an actuator 16 at each side of the tilting arrangement 8. In the shown embodiment, the actuators 16 have a first support 17 at the underside of the top section 6. This support 17 has a fixed angle relative to the top section 2. The actuators 16 are provided a rotatable connection to the second support 18 on the frame 3. This embodiment makes it possible to move the tilt axis 9 to a point under the frame 3.

Claims

1. A machine (1), preferably an excavator, a felling machine, a brush cutter or a demolition machine, including:

- an undercarriage (2) including a frame (3); - propulsion means (4) at each side of a centre plane (5) through the frame (3), the centre plane (5) being parallel with the driving direction of the machine;

- a top section (6) arranged above the undercarriage (2) and including a driver position

(7);

- a tilting arrangement (9) disposed between the undercarriage (2) and the top section (6) for tilting the top section (6) in relation to the undercarriage (2) about a tilt axis (9) through the machine (1);

- at least one telescopic arm (10) at each side of the centre plane (5), the telescopic arms (10) being mounted between the frame (3) and the propulsion means (4) for changing the distance between the propulsion means (4); characterised in that the tilt axis (9) is located in the centre plane (5) and that the telescopic arms (10) may be displaced independently of each other.

2. Machine according to claim 1, characterised in that the tilt axis (9) is optionally situated largely at the lowest point of the frame or at a point under the frame (3).

3. Machine according to any of claims 1-2, characterised in that the telescopic arms (10) are arranged at a downwardly directed angle.

4. Machine according to any preceding claim, characterised in that it includes a rotary mechanism (11) which is disposed between the tilting arrangement (8) and the top section (6) for rotating the top section (6) about a largely vertical axis (12) through the top section (6).

5. Machine according to any preceding claim, characterised in that the propulsion means (4) are optionally selected among caterpillar tracks or wheels.

6. Machine according to any preceding claim, characterised in that a first hinge means (13) is disposed between the propulsion means (4) and the telescopic arms (10) for pivoting the propulsion means (13) about a longitudinal axis (14) through the propulsion means (4).

7. Machine according to any of claims 1-6, characterised in that the tilting arrangement (8) includes a second hinge means (15) for tilting about the tilt axis (9).

8. Machine according to any of claims 1-6, characterised in that the tilting arrangement (8) includes at least one actuator (16) at each side of the centre plane (5), that each actuator (16) at one end has a fixed angle relative to a first support (17), that each actuator at its other end is provided with a rotatable connection to a second support (18), and that the first support (17) and the second support (18) are optionally disposed on the undercarriage (2) or the top section (6), respectively.

9. Machine according to any preceding claim, characterised in that the tilting arrangement (8), the telescopic arms (10), the rotary mechanism (11), the first hinge means (13) and the second hinge means (15) are optionally provided with at least one actuator which is optionally selected among hydraulic, electric or pneumatic actuators.

10. Machine according to any preceding claim, characterised in that the tilting arrangement (8), the telescopic arms (10), the rotary mechanism (11), the first hinge means (13) and the second hinge means (15) are optionally provided with at least one locking arrangement which is optionally selected among mechanical locking, hydraulic locking, electric locking or pneumatic locking.