SAFETY SYSTEM FOR MOBILE APPARATUS

Abstract

Mobile apparatus comprising a main frame with displacing means; a sub-frame connected rotatably to the main frame; an operating arm connected to the sub-frame and comprising at least a first and a second articulation which are connected pivotally to each other, which operating arm can be transformed from an operating position to a transport position; drive members configured to move at least the first and second articulations of the operating arm; operating instruments controllable by a driver and provided close to a driver position on the sub-frame; measuring instruments configured to measure position data relating to a position of the first articulation and a position of the second articulation; and a control system configured to receive operational data from the operating means and position data from the measuring instruments; and configured to control the drive members in accordance with the received position data and the operational data.

Claims

1. A mobile apparatus, comprising: a main frame with displacing means; a sub-frame connected rotatably to the main frame; an operating arm connected to the sub-frame and comprising at least a first, a second and a third articulation which are connected pivotally to each other, which operating arm is configured to fold the at least three articulations adjacently or against each other in the transport position and to be transformed from an operating position to a transport position; wherein the third articulation is foldable against the second articulation, and these third and second articulations are together foldable along the first articulation, wherein at least one of the second and third articulations is locked relative to the first articulation or relative to the sub-frame; drive members configured to move at least the first and second articulations of the operating arm; operating instruments controllable by a driver and provided close to a driver position on the sub-frame; measuring instruments configured to measure position data representative of at least: a position of the second articulation relative to the first articulation or relative to the sub-frame; and/or a position of the first articulation relative to the sub-frame; and/or a position of the third articulation relative to the first articulation and/or relative to the second articulation and/or relative to the sub-frame; and a control system configured to receive operational data from the operating means and position data from the measuring instruments; and configured to control the drive members in accordance with the received position data and the operational data, wherein the control system is configured to allow a transformation to the transport position only when the angle between the first articulation and the sub-frame lies within a predetermined range.

2. The mobile apparatus as claimed in claim 1, wherein the control system is configured to control the drive members such that a drive member of the second articulation and/or a drive member of the third articulation continues to generate force after reaching an end point in order to hold the articulation in position during locking and/or unlocking of one of the articulations; and/or that a measuring instrument is provided in order to determine whether locking components of an articulation are in the correct position before locking/unlocking is performed.

3. The mobile apparatus as claimed in claim 1, wherein the control system is configured to control the drive members such that the speed at which the second articulation moves relative to the first articulation and/or the third articulation relative to the second articulation is modified in accordance with the position data.

4. The mobile apparatus as claimed in claim 1, wherein the control system is configured to perform the transformation to the transport position in a first and a second phase; wherein in the first phase the operating arm is brought into a starting position in which the first articulation makes an angle lying within a predetermined range with the sub-frame and the second articulation makes an angle lying in a predetermined range with the first articulation; and wherein in the second phase the operating arm is moved to the transport position.

5. The mobile apparatus as claimed in claim 1, wherein the operating instruments comprise a transport position command instrument which can be operated by a driver in order to move the operating arm to the transport position and which is configured to transmit a transport position command to the control system; and that the control system is configured for the purpose, after receiving a transport position command, of controlling the drive members on the basis of the position data during the movement to the transport position.

6. The mobile apparatus as claimed in claim 1, wherein the control system is configured to receive position data from the measuring instruments at successive points in time during movement from the operating position to the transport position and to control the drive members in accordance with these position data received at successive points in time.

7. The mobile apparatus as claimed in claim 1, wherein the measuring instruments are configured to measure position data representative of the distance between the main frame and the displacing means and/or of the rotation of the sub-frame relative to the main frame.

8. The mobile apparatus as claimed in claim 1, wherein the measuring instruments comprise one or more of the following: a linear measuring instrument, a position or contact measuring instrument, an angle measuring instrument, a rotation measuring instrument.

9. The mobile apparatus as claimed in claim 1, wherein the control system is configured to allow a transformation to the transport position only when the angle between the main frame and the sub-frame lies within a predetermined range.

10. The mobile apparatus as claimed in claim 1, wherein the control system is configured, during transformation of the operating arm to the transport position and vice versa, to control only the articulations of the operating arm, and optionally an articulation lock, and no other movements of the mobile apparatus can be controlled.

11. The mobile apparatus as claimed in claim 1, wherein, further comprising: a damping system between the main frame and at least one displacing means for damping the movement of the main frame relative to the displacing means; wherein the control system is configured to block the damping system in accordance with the received operational data; wherein the damping system is preferably active between the main frame and all displacing means.

12. The mobile apparatus as claimed in claim 11, wherein a measuring instrument is integrated into the damping system.

13. The mobile apparatus as claimed in claim 1, wherein the displacing means comprise at least a first and a second displacing means, and wherein the mobile apparatus further comprises a damping system with: a first damping unit between the main frame and the first displacing means for damping the movement of the main frame relative to the first displacing means; and a second damping unit between the main frame and the second displacing means for damping the movement of the main frame relative to the second displacing means independently of the first damping unit; and wherein the control system is configured to control the first and second damping units in accordance with the received operational data; wherein a first measuring instrument for measuring a position of the main frame relative to the first displacing means is preferably integrated into the first damping unit (113); and a second measuring instrument for measuring a position of the main frame relative to the second displacing means is integrated into the second damping unit.

14. The mobile apparatus as claimed in claim 1, wherein the damping system comprises one or more of the following: at least one damping unit comprising a cylinder or a bellows under pressure; and at least one damping unit with associated damping characteristic, wherein the control system is configured to set the or each damping characteristic.

15. The mobile apparatus as claimed in claim 1, wherein the damping system comprises a plurality of damping units and that the control system is configured to block one or more of the damping units in a blocked position, which blocked position can for instance be a high blocked position, in which the main frame is located in a highest position relative to the displacing means, a low blocked position, in which the main frame is located in a lowest position relative to the displacing means, or a blocked intermediate position located between the highest and lowest position.

16. The mobile apparatus as claimed in claim 1, wherein the control system is configured to block the damping system in accordance with angle data representative of the rotation of the sub-frame relative to the main frame.

17-18. (canceled)

19. The mobile apparatus as claimed in claim 1, further comprising a bumper system coupled to the operating arm in the transport position; which bumper system is configured and shaped to limit the impact of the operating arm on other road users in the case of collision.

20. The mobile apparatus as claimed in claim 1, further comprising: a lifting device mounted on the main frame; and a bumper system coupled to the lifting device in the transport position; which bumper system is configured and shaped to limit the impact of the lifting device on other road users in the case of collision.

21. A mobile apparatus comprising: a main frame with displacing means; a sub-frame connected rotatably to the main frame; an operating arm connected to the sub-frame and comprising at least a first and a second articulation which are connected pivotally to each other, which operating arm can be transformed from an operating position to a transport position; drive members configured to move at least the first and second articulations of the operating arm; operating instruments controllable by a driver and provided close to a driver position on the sub-frame; measuring instruments configured to measure position data relating to a position of the first articulation and a position of the second articulation; and a control system configured to receive operational data from the operating means and position data from the measuring instruments; and configured to control the drive members in accordance with the received position data and the operational data.

22. A mobile apparatus comprising: a main frame; displacing means; a sub-frame connected rotatably to the main frame; an operating arm connected to the sub-frame; drive members configured to move the operating arm; a damping system between the main frame and at least one displacing means for damping the movement of the main frame relative to the displacing means; operating instruments controllable by a driver and provided close to a driver position on the sub-frame; and a control system configured to receive operational data from the operating means; and configured to block the damping system in accordance with the received operational data.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0178] The above stated and other advantageous features and objects of the invention will become more apparent, and the invention better understood, on the basis of the following detailed description when read in combination with the accompanying drawings, in which:

[0179] FIG. 1A is a side view of a first embodiment of a mobile apparatus in a first articulated operating position;

[0180] FIG. 1B is a side view of the first embodiment in a second articulated operating position;

[0181] FIG. 1C is a side view of the first embodiment in a first lifting operating position;

[0182] FIG. 1D is a side view of the first embodiment in a second lifting operating position;

[0183] FIG. 1E is a side view of the first embodiment in a transport position, with bumper system;

[0184] FIG. 1F is a side view of an end part 31 of the sub-frame 30 which shows how the rotation point between the third and the second articulation of the first embodiment moves during folding-up of the operating arm;

[0185] FIG. 1G is a top view of the first embodiment in the transport position with a bumper mounted on the operating arm and a bumper mounted on the lifting device;

[0186] FIG. 2A is a schematic side view of a second embodiment of a mobile apparatus in a transport position, wherein the displacing means comprise caterpillars;

[0187] FIG. 2B is a schematic side view of a part of the second embodiment during the transformation from operating arm 40 to the transport position;

[0188] FIG. 3A is a schematic side view of a third embodiment of a mobile apparatus in an operating position, wherein the displacing means comprise caterpillars;

[0189] FIG. 3B is a schematic side view of the third embodiment in the transport position;

[0190] FIG. 3C is a schematic top view of the third embodiment in the transport position;

[0191] FIGS. 4A-4D show four variants of measuring instruments for measuring the position of a first articulation 41 relative to a second articulation 42;

[0192] FIG. 5 shows a diagram of an embodiment of the control system 90 and the components connected to the control system;

[0193] FIG. 6 is a schematic front view of an embodiment of a mobile apparatus with a double wishbone suspension of the displacing means;

[0194] FIG. 7 is a schematic top view of an embodiment of a mobile apparatus with a double wishbone suspension of the displacing means and with a lifting device and power takeoff;

[0195] FIGS. 8A and 8B show schematically a front and top view of an embodiment of a mobile apparatus with a damping system 110 per axle;

[0196] FIG. 9 is a schematic side view of an embodiment of a mobile apparatus with a damping system with leaf springs:

[0197] FIGS. 10A, 10B and 10C show schematically a side view, a top view and a partial side view of embodiments of a mobile apparatus with a damping system 110 with additional longitudinal arms 131, 132;

[0198] FIG. 10D is a schematic top view of a variant of the embodiment of FIG. 10B;

[0199] FIG. 10E is a schematic side view similar to the side view of FIG. 10C in which a mobile apparatus with damping system is positioned on an incline;

[0200] FIG. 10F is a schematic side view similar to the side view of FIG. 10C in which a mobile apparatus with damping system and caterpillar tracks is positioned on an incline;

[0201] FIGS. 11A and 11B show schematically a top and side view of an embodiment of a mobile apparatus with lifting device and power takeoff which co-displace with an axle;

[0202] FIGS. 12A and 12B show schematically a top and side view of an embodiment of a mobile apparatus with lifting device and power takeoff which co-displace with the main frame;

[0203] FIG. 13 shows a diagram of an embodiment of the control system 90 and the components connected to the control system; and

[0204] FIG. 14 shows an embodiment of a damping unit.

[0205] FIGS. 1A-1G illustrate a first embodiment of a mobile apparatus. The mobile apparatus comprises a main frame 10 with displacing means 21, 22, 23, 24, here wheels, a sub-frame 30 connected rotatably to the main frame and an operating arm 40 connected to sub-frame 30. Operating arm 40 comprises a first articulation 41, a second articulation 42 and a third articulation 43 which are connected pivotally to each other, see rotation point 44 between third articulation 43 and second articulation 42 and rotation point 46 between second articulation 42 and first articulation 41. First articulation 41 is connected around rotation point 45 to sub-frame 30. Operating arm 40 can be transformed from an operating position (FIGS. 1A-1D) to a transport position (FIGS. 1E and 1G). The mobile apparatus further comprises first, second and third drive members 51a, 51b; 52; 53 configured to move respectively the first articulation relative to the sub-frame, the second articulation relative to the first and the third articulation relative to the second.

[0206] The first embodiment further comprises operating instruments 60 controllable by a driver and provided close to a driver position 70 on sub-frame 30, and measuring instruments 81, 82, 83 (not shown in FIGS. 1A-1G, but shown in FIG. 5) which are configured to measure position data relating to a position of the first articulation and a position of the second articulation; and a control system 90 (not shown in FIGS. 1A-1G, but shown in FIG. 5) which is configured to receive operational data from operating means 60 and position data from measuring instruments 81, 82, 83; and which is configured to control the drive members in accordance with the received position data and the operational data. An embodiment thereof is shown in FIG. 5.

[0207] Operating instruments 60 can comprise a transport position command instrument which can be operated by a driver for the purpose of moving the operating arm to the transport position and which is configured to transmit a transport position command to the control system; and control system 90 can be configured to control the drive members 51a, 51b; 52, 53, after receiving a transport position command, on the basis of the position data during movement to the transport position. A drive member 55 for locking the articulations (see FIG. 1F) and a drive member 54 for controlling the position of an implement relative to third articulation 43 can be controlled by control system 90.

[0208] Measuring instruments 81, 82, 83, 85 etc. can be configured to measure position data representative of a position of the second articulation relative to the first articulation or relative to the sub-frame; and/or a position of the first articulation relative to the sub-frame; and/or position data representative of a position of the third articulation relative to the first articulation and/or relative to the second articulation and/or relative to the sub-frame; and/or position data representative of the distance between the main frame and the displacing means and/or of the rotation of the sub-frame relative to the main frame.

[0209] Measuring instruments 81, 82, 83, 85 etc. can comprise one or more of the following: a linear measuring instrument 80 (for instance an MTS sensor), wherein this measuring instrument is provided in a drive member 50 between a first articulation 41 and a second articulation 42, see FIG. 4C, or outside it, see FIG. 4D; an angle measuring instrument 80, see FIG. 4B, for measuring the inclination of second articulation 42; a rotation measuring instrument 80, see FIG. 4A, for measuring the rotation of first articulation 41 relative to second articulation 42; a position or contact measuring instrument. In the embodiment of FIG. 1A measuring instruments can for instance be provided in one or more of the drive members 51a, 51b; 52, 53, 54, 55.

[0210] The operating arm can form an articulated operating arm 40 in an articulated operating position; wherein the first articulation is connected to the sub-frame and wherein an implement 100 can be mounted on the third articulation; wherein the operating arm is configured to fold the first, second and third articulations adjacently or against each other in order to transform operating arm 40 to a single lifting arm in a lifting operating position; wherein in the lifting operating position an implement 100 can be mounted on the third articulation. The measuring instruments can comprise a measuring instrument configured to measure the position of the first articulation relative to the sub-frame in the articulated operating position and to measure the position of the lifting arm relative to the sub-frame in the lifting operating position, and/or comprise a measuring instrument configured to measure the position of the implement in the articulated operating position and in the lifting operating position.

[0211] Control system 90 can be configured

[0212] to receive position data from measuring instruments 81, 82, 83 at successive points in time during the movement from the operating position to the transport position and to control the drive members 51-55 in accordance with these position data received at successive points in time; and/or

[0213] to fold the at least three articulations adjacently or against each other in the transport position and to lock them relative to each other; and/or

[0214] to fold third articulation 43 against second articulation 42 and to fold this third and second articulation together along first articulation 41, wherein at least one of the second and third articulations 42, 43 is locked relative to first articulation 41 or relative to sub-frame 30; and/or

[0215] to control the rotation of the implement in the direction of the sub-frame or the main frame in accordance with the measured position of the implement and of the first articulation or the lifting arm;

[0216] to allow a transformation to the transport position only as soon as the angle between the main frame and the sub-frame lies within a predetermined range; and/or

[0217] to receive rapid-coupling angle data representative of the angle between a rapid-action coupling 105 attached to operating arm 40 and the operating arm and to control the movement to the transport position in accordance with the rapid-coupling angle data; and/or

[0218] to allow a transformation to the transport position only when the angle between the first articulation and the sub-frame lies in a predetermined range; and/or

[0219] to perform the transformation to the transport position in a first and a second phase; wherein in the first phase the operating arm is brought into a starting position in which the first articulation makes an angle lying within a predetermined range with the sub-frame and the second articulation makes an angle lying within a predetermined range with the first articulation; and wherein in the second phase the operating arm is moved to the transport position. Note that the first phase can also take place manually by a driver in order to avoid the operating arm colliding with other elements in the surrounding area; and/or

[0220] to control only the articulations of the operating arm and optionally an articulation lock during transformation of the operating arm to the transport position, and vice versa, and no other movements of the mobile apparatus can be controlled; and/or

[0221] to control the drive members such that the speed at which the second articulation moves relative to the first articulation and/or the third articulation relative to the second articulation is modified in accordance with the position data; and/or

[0222] to control the drive members such that a drive member of second articulation 42 and/or a drive member of third articulation 43 continues to generate force after reaching an end point in order to hold the articulation in position during locking and/or unlocking of one of the articulations. See also FIG. 1F: during the transformation of the rotation point 44 (with a pin) moves to rotation point 45 along a path B, wherein the movement slows as rotation point 44 with pin approaches rotation point 45 and the associated drive member continued to generate force during locking by locking drive member 55. Control system 110 can be configured for this purpose to control drive member 52 of second articulation 42 and/or drive member 53 of third articulation 43 such that they continue to generate force after reaching the end point in order to hold articulations 42, 43 in position during locking and/or unlocking of the articulations. A measuring instrument (not shown) can further be provided in order to assess whether pin 44 coincides at the correct location with rotation point 45 before unlocking and movement of the second and/or third articulation in articulated position or, conversely, locking and subsequent movement of the second and/or third articulation in transport or single operating arm position can be initiated.

[0223] The measuring instruments can comprise a measuring instrument 85 for measuring a value representative of the angle through which the sub-frame is rotated round a vertical axis relative to the main frame, see also FIG. 5 and FIG. 3C. In the transport position of the first embodiment (FIG. 1E) the third articulation is folded against the second articulation, and these third and second articulations are together folded along the first articulation, and the operating arm thus folded together is oriented obliquely downward from the sub-frame and arm 40 is situated between the displacing means. In the variant of FIGS. 2A and 2B the transport position (FIG. 2A) is a non-folded position of operating arm 40. In the variant of FIGS. 3A and 3B and 3C first articulation 41 is folded in the transport position against second articulation 42 and the folded operating arm 40 is oriented obliquely upward over sub-frame 30 (see FIGS. 3B and 3C).

[0224] The mobile apparatus can further comprise a lifting device 170 which is mounted on main frame 10, the measuring instruments can comprise a measuring instrument configured to measure the position of lifting device 170 and control system 90 can be configured to avoid collisions between lifting device 170 and other parts of the mobile apparatus on the basis of the measured position of the lifting device.

[0225] Control system 90 can comprise a bus system.

[0226] FIGS. 1E and 1G illustrate a mobile apparatus in a transport position. The mobile apparatus comprises a main frame 10 with displacing means 20; a sub-frame 30 connected rotatably to the main frame; an operating arm 40 connected to sub-frame 30; a lifting device 170, a first bumper system 200 coupled to operating arm 40; and a second bumper system 210 coupled to lifting device 170. First bumper system 200 is configured and shaped in order to limit the impact of operating arm 40 on other road users in the case of collision. Second bumper system 210 is configured and shaped to limit the impact of the lifting device on other road users in the case of collision. First bumper system 200 is coupled to the last articulation of operating arm 40 via a quick change system 105 which is mounted via a parallelogram linkage on an outer end of the last articulation of operating arm 40. According to another variant, a rotating and/or tilting part, for instance a so-called tilt rotator, can be used. First bumper system 200 comprises a bumper which extends from the displacing means as far as the last articulation of operating arm 40. Lifting device 170 is coupled to second bumper system 210 on a rear side of the mobile apparatus. As described above, operating arm 40 has three articulations and operating arm 40 is configured to fold the at least three articulations adjacently or against each other in the transport position. First bumper system 200 can then be attached after operating arm 40 has been brought into the transport position.

[0227] FIGS. 6-12 show a mobile apparatus comprising: a main frame 10; displacing means 21, 22, 23, 24; a sub-frame 30 connected rotatably to the main frame; an operating arm 40 connected to the sub-frame and comprising at least a first and a second articulation connected pivotally to each other; a damping system 110 between the main frame and at least one displacing means for damping the movement of the main frame relative to the displacing means; operating instruments (not shown) controllable by a driver and provided close to a driver position on the sub-frame; a control system (not drawn in FIGS. 6-12 but shown in FIG. 13) which is configured to receive operational data from the operating means; and which is configured to block the damping system in accordance with the received operational data. Damping system 110 is active between the main frame and all displacing means. The mobile apparatus preferably comprises a measuring instrument 87 between at least one displacing means and the main frame and/or a measuring instrument 87 between all displacing means and the main frame, see also FIG. 13. The one or more measuring instruments can comprise one or more of the following: a linear measuring instrument, a position or contact measuring instrument, an angle measuring instrument, a rotation measuring instrument. A measuring instrument 87 can be integrated into damping system 110. Damping system 110 comprises at least one damping unit 113, also referred to as suspension unit, which for instance comprises a cylinder or a bellows under pressure. FIG. 14 shows a damping unit 113 with a cylinder which is placed under pressure by a pressure medium 118 via a controllable valve 117 for the purpose of controlling or blocking the damping cylinder. Damping unit 113 typically has an associated damping characteristic, and control system 90 can be configured to set the or each damping characteristic. The damping system can comprise a plurality of damping units 113 and control system 90 can be configured to block one or more of the damping units in a blocked position, which blocked position can be for instance a high blocked position, in which the main frame is located in a highest position relative to the displacing means, a low blocked position, in which the main frame is located in a lowest position relative to the displacing means, or a blocked intermediate position located between the highest and lowest positions.

[0228] In the embodiment of FIGS. 6 and 7 damping system 110 comprises a double wishbone suspension 110 for each displacing means. The double wishbone suspension 110 comprises a damping unit 113 and a number of pivot arms 111, 112.

[0229] In the variant of FIGS. 8A and 8B damping system 110 comprises a damping unit 113 between a first axle 141 of the displacing means and the main frame. The mobile apparatus comprises a support structure 15 provided on the main frame, which support structure is provided with a gear ring or rotary bearing for the sub-frame, and provided between first axle 141 and support structure 15 is an arm 120 which is pivotally connected at its outer ends. Transverse arm 120 is active between first axle 141 and the main frame in order to stabilize first axle 141 laterally relative to the main frame.

[0230] In the variant of FIG. 9 leaf springs are used in damping system 110.

[0231] Provided in the variant of FIGS. 10A-10C are a first and a second arm 131, 132 which extend in the direction of travel, wherein an outer end of first arm 131 is positioned close to a first displacing means 21 on the first axle and wherein the other outer end of the first arm is positioned close to a first outer side 18 of support structure 15; and wherein an outer end of second arm 132 is positioned close to a second displacing means 23 on first axle 141 and wherein the other outer end of the second arm is positioned close to a second outer side 19 of support structure 15. The mobile apparatus comprises a second axle 142 which is connected to displacing means 22, 24, and provided between second axle 142 and support structure 15 are one or more arms 131, 132 which are pivotally connected at their outer ends. First axle 141 is further coupled pivotally by a V-shaped arm 150 to the support structure, wherein V-shaped arm 150 is configured to realize a lateral stabilization of the first axle relative to support structure 15. Second axle 142 of the main frame is also provided with a V-shaped arm 150 between second axle 142 and support structure 15. It is noted that the V-point of V-shaped arms 150, which is now connected to respectively first axle 141 and second axle 142, can also be connected to support structure 15, wherein the outer ends of the V are then connected to first axle 141 and second axle 142. This is illustrated in FIG. 10D. Instead of V-shaped arms, two separate arms can also be used which can together bring about the effect of the V-shaped arms.

[0232] FIGS. 10E and 10F illustrate a first and a second embodiment in which the mobile apparatus is provided with respectively tyres and caterpillars and in which a damping system is provided. The mobile apparatus comprises a first axle 141 and a second axle 142 which are connected to respective displacing means 21, 22. Between each axle 141, 142 and main frame 10 can be provided one or more arms 131, 132 which are pivotally connected at their outer ends. Each axle 141, 142 can further be coupled pivotally by a V-shaped arm 150 to main frame 10, wherein V-shaped arm 150 is configured to realize a lateral stabilization of each axle 141, 142 relative to main frame 10. A measuring instrument (not shown) is further provided for the purpose of measuring position data representative of the position of main frame 10 and/or sub-frame 30. The mobile apparatus comprises a control system (provided in sub-frame 30 or in main frame 10) which is configured to control damping system 110 in accordance with the measured position data. The control system can then be configured, on the basis of the measured position data, to change the position of sub-frame 30 using damping system 110. Sub-frame 30 can in this way be positioned for instance substantially level or substantially parallel to the horizontal so that it operates more safely and more efficiently as illustrated in FIGS. 10E and 10F. It is also possible to mount sub-frame 30 at a fixed angle, for instance while performing operations on an uneven terrain. According to yet another possibility, the angle is varied in accordance with the measured position data, for instance in order to obtain a stable road-holding when the mobile apparatus travels by road.

[0233] In the variant of FIGS. 11A and 11B a lifting device 170 and a power takeoff 160 are connected to at least one displacing means or to an axle coupled to a displacing means, and thereby not spring-mounted and/or damped relative to at least said displacing means.

[0234] In the variant of FIGS. 12A and 12B a lifting device 170 and a power takeoff 160 arc connected to a spring-mounted part of the main frame, and thereby spring-mounted and/or damped relative to at least one displacing means or an axle with displacing means.

[0235] The skilled person will appreciate that the invention is not limited to the above described embodiments and that many modifications and variants are possible within the scope of the invention, which is defined solely by the following claims.