Patent Application
20230340756
The invention relates to a work machine.
Various work machines, such as wheel loaders, backhoe loaders or skid steer loaders, are known from the prior art, in which a working unit is attached to the front end of the vehicle. This working unit can be a shovel, a stacking fork or other working units commonly used in the agricultural and construction industries. The working unit, for example the bucket, can be raised or lowered. For this purpose, the wheel loader (see
It is the object of the present invention to overcome the disadvantages of the prior art. In particular, it is the object of the invention to provide a work machine, or a vehicle, which is suitable for the common work tasks of today's work machines and at the same time has a high degree of maneuverability and flexibility. Furthermore, it is the object of the invention to provide a work machine, respectively a vehicle, which has a lower weight with a constant performance as well as a higher agility and a lower parts density. Furthermore, it is the object of the invention to provide a work machine or a vehicle, which can be used flexibly as a basic carrier vehicle for various working units. In addition, it is the object of the invention to provide a work machine or a vehicle with which an increase in productivity is made possible and which also meets modern ecological requirements.
The features disclosed herein lead to the solution of the object. Advantageous embodiments are also described herein and in the dependent claims.
For this purpose, vehicles with a displaceable weight and a displaceable working unit are to be used. Both are to be displaceable in a sufficiently wide range, thus enabling a very compact vehicle and keeping the vehicle's center of gravity in an ideal range. The displacement of the displaceable weight shall be done by a rod system, which guides the displaceable weight very close to the area of the main vehicle axle, or above it. Also, the displacement of the working unit is to be done by a pivot arm and a working arm that guides the working unit very close to the area of the main vehicle axle. For this purpose, a vehicle structure is to be found in which the position and movement space of the pivot arm, the working arm for receiving and moving the working unit, and the position and movement space of the displaceable weight are made possible.
A work machine according to the invention comprises precisely one main vehicle axle, wheel elements arranged on both sides of the main vehicle axle, a working unit or a holder for a working unit, whereby this is arranged on a vehicle frame by means of at least one pivot arm with at least one rotatably mounted working arm. Furthermore, the work machine according to the invention comprises at least one displaceable weight, wherein this is arranged on the vehicle frame by at least one rod system. In this case, the displaceable weight, the rod systems and the pivot arms with the working arms are each assigned exclusively one movement channel along the longitudinal direction of the vehicle.
A work machine according to the invention thus has, in contrast to a prior art work machine, a structure which enables it to move both the working unit with its large mass and the heavy displaceable weight into the central region of the work machine, which is located in the vicinity of the main vehicle axle. Thus, the center of gravity of the vehicle can always be kept in this range, thus achieving a stable position for the vehicle. In addition, the work machine according to the invention can thus takes up a very compact position, in contrast to a machine of the prior art. This results in the advantage that a work machine according to the invention can be used in narrow locations, such as often occur on inner-city construction sites, where it can be operated in a very agile manner. In addition, this results in the advantage that a significantly lighter work machine can be provided that can nevertheless lift and transport the same usable load as the comparable prior art work machine. This is made possible by the fact that, in the case of the work machine according to the invention, the load is located very close to the main vehicle axle when it is lifted, similar to the situation with prior art counterbalanced forklifts. Once this has been raised to the point where the working unit and/or the load is above the wheel elements, it can be moved even further towards the main vehicle axle. This is made possible by the fact that the working arms and pivot arms can move freely and independently of the movements of the displaceable weight in the movement channels assigned to them. For lifting the load from the ground, the displaceable weight is extended far to the rear. Thus, due to the leverage effect of its position, this can be light and still allow high loads on the working unit without the vehicle losing its stable position. The comparably low displaceable weight has a beneficial effect on the overall weight of the vehicle. As soon as the working unit with the picked-up load is retracted further over the main vehicle axle, the displaceable weight is retracted further in return. This is made possible by the fact that both the displaceable weight and the rod systems arranged thereon are each assigned to their own movement channels, as a result of which the movements of the working unit and the movements of the displaceable weight essentially do not interfere with each other.
Thus, in contrast to a work machine of the prior art, the work machine according to the invention has a significantly better ratio of payload to dead weight. Particularly in the case of smaller work machines, a further advantage is that the work machine according to the invention can be transported on simple vehicle trailers without exceeding their maximum permissible total weight. A further advantage of the machine according to the invention is that, due to its lower weight, it can be used inside buildings on higher floors without exceeding their maximum permissible floor load. Furthermore, it can be moved to different floors by means of the elevators available in the buildings without exceeding the permissible payload of the elevators.
In a preferred embodiment, the displaceable weight and its assigned movement channel take up a central position on the vehicle's transverse axis. This results in the advantage that a significant proportion of the vehicle width can be allocated to the displaceable weight and the assigned movement channel. Since the displaceable weight also represents a container that can contain various functional elements, such as energy converters, oil tanks and/or hydraulic pump, this ideally takes up the central position in the transverse direction. Thus, only one such container is required and thus only one centrally located movement channel. Further out to the side, one rod system per side is arranged for displacement of the displaceable weight, whereby in a particularly preferred embodiment at least two are required for this purpose. Thus, the working arms and the pivot arms are arranged laterally on the very outside. In the preferred embodiment, the movement channel for the displaceable weight is arranged in such a way that its lower limit lies above the main vehicle axis and its upper limit lies below the transverse rods required for the lateral stability of the rod systems. This has the advantage that the rod systems can be made very narrow, since their lateral stability is ensured by the use of one or more transverse rods. This has the advantage that the movement channels for the rod systems can be made very narrow and that the vehicle width can therefore be comparably narrow.
In a typical embodiment, the pivot arms and the working arms arranged thereon each lie in one level. This results in the advantage that the forces exerted by the load of the working unit, as well as those exerted by the adjusting elements, for example hydraulic cylinders, do not generate excessively high bending moments. In addition, this results in the advantage that the movement channels required for the free movements can be made narrow. As a result, the work machines according to the invention can have an overall narrow design.
In a further embodiment, pivot arms and working arms are arranged laterally, i.e. in the direction of the transverse axis of the vehicle, on the outside in each case, adjacent to the movement channels of the rod systems. This has the advantage that the pivot arms and working arms can absorb the forces acting unevenly on the working unit.
In another typical embodiment, the wheel elements are arranged in the same level as the pivot arms and the working arms. This results in the advantage that the work machine according to the invention can be built very narrowly. This makes it very compact not only in its vehicle length but also in its width. When used inside buildings, such work machines have the advantage that they can pass through door openings with common opening widths, for example.
In a further embodiment, a work machine according to the invention comprises only a pivot arm and a working arm arranged thereon. These take up a central position, whereby a movement channel for the pivot arm and the working arm is also assigned to a central position on the transverse axis of the vehicle. The advantage of this embodiment is that fewer drive elements are required to move the pivot arm and the working arm compared to machines with several pivot arms and working arms. If electric actuators are used, the often used hydraulic system consisting of oil tank, hydraulic pump, filter, valves and hoses can be omitted. The electric actuators, as often used in the prior art for driving robot arms, can be supplied with power directly from an electric storage unit via electric cables. This means that the number of components required can be smaller. However, the electric actuators themselves are more complex and expensive than hydraulic cylinders. Therefore, a design of the work machine according to the invention is advantageous when electric actuators are used if the number of drives or actuators required is small.
On both sides of the movement channel for the pivot arm and the working arm and adjacent thereto are arranged two movement channels which allow the movements of at least two rod systems for fastening and displacing displaceable weights. Laterally adjacent to the movement channels of the rod systems, i.e. in the direction of the transverse axis of the vehicle on the very outside in each case, at least one movement channel is arranged on each side, which enables the movements of at least one displaceable weight in each case. In this embodiment two displaceable weights are thus used. If all drives of the work machine are electric drives, no further installation space is required in addition to electric energy storage devices, such as for oil tanks, pumps and valves. Electrical energy storage systems can be easily divided between two remote rooms without incurring significant constructional expenses. The effort is largely limited to the use of electrical cable connections.
In a preferred embodiment, the two displaceable weights are fixedly connected to each other at their rear end. This allows them to be moved by a single drive element or a single actuator. A single control signal is thus sufficient for this. Since the connection of the two displaceable weights is arranged at the rear end of the vehicle, the movements of the elements of the other movement channels such as the pivot arm and the working arm as well as the rod systems are not disturbed.
A further work machine according to the invention comprises a further work unit or a further holder for a further working unit. Furthermore, the further work machine according to the invention comprises precisely one further main vehicle axle, wherein further wheels are arranged on both sides of the further main vehicle axle. A separate further drive unit is assigned in each case to the further wheels arranged on both sides of the further main vehicle axle. Furthermore, the further work machine according to the invention comprises at least one further auxiliary wheel, the further auxiliary wheel comprising at least one device for detecting the load.
Furthermore, the further work machine according to the invention comprises a further displaceable weight, wherein the position of the further displaceable weight can be regulated via a control system in such a way that the load on the further auxiliary wheel lies within a lower and upper limit value. Furthermore, the further work machine according to the invention comprises at least one control system, the control system comprising at least one control loop which, when the load on the further auxiliary wheel falls below the lower limit value, actuates the further drive units in such a way that the applied drive torque is changed in such a way that the vehicle is thereby prevented from tipping over. For this purpose, vehicles with a further displaceable weight and a further displaceable working unit are to be used.
A preferred embodiment of the further work machine according to the invention thus has two driving modes. In the self-balancing driving mode, the further auxiliary wheel is not on the ground. The vehicle balances around the further main vehicle axle with the aid of tilt sensors and is controlled by the amount of torque and speed of the further wheels on the further main vehicle axle and by the positional displacement of the further displaceable weight. In the driving mode of the additional auxiliary wheel, on the other hand, the additional auxiliary wheel is on the ground and takes on a load that is determined by load sensors and can be controlled by a position displacement of the additional displaceable weight within an upper and lower limit value.
The further work machine according to the invention thus has the option of always placing the main load on the further main vehicle axle and keeping the load on the further auxiliary wheel in an area that can be predefined by the limit values. Due to the low load on the further auxiliary wheel, the maneuverability of the further work machine in this driving mode remains similarly good as in the driving mode self-balancing. However, the demands on control and controllability are higher in self-balancing, especially in difficult terrain. In this case, the control speed available to the vehicle for driving on two wheels may be too slow. The rapidly changing forces that can act on the further work machine as a result of the further work unit, or forces that can act impulsively on the further wheels as a result of a very uneven road surface, can be better controlled if the further auxiliary wheel takes over a proportion of the load, even if this proportion is significantly lower than that of the further wheels of the further main vehicle axle.
Furthermore, when balancing in difficult terrain or standing on two more wheels, the vehicle requires more energy for the further drive units. For a modern ecological further work machine, the optimal use of energy is an essential requirement. Thus, the self-balancing driving mode is suitable for driving on even road surfaces and at higher driving speeds. The advantage is that the vehicle does not experience pitching accelerations and pitching movements due to road unevenness in the driving mode Self-balancing. The additional energy consumption of the other drive units required for balancing is low at higher driving speeds. The driving mode auxiliary wheel, on the other hand, is suitable for driving on uneven road surfaces, with rapidly changing forces that can act on the further work machine, for example, due to the further working unit, when driving slowly and when stationary.
In order to keep the load on the further auxiliary wheel small and thus keep the maneuverability and agility of the further work machine similar to that of driving in self-balancing driving mode, a control loop in the control system of the further work machine according to the invention detects the load on the further auxiliary wheel. This can be done by load sensors arranged on the further auxiliary wheel or on a further holder for the further auxiliary wheel. This load changes as the additional displaceable weight is displaced. As the further displaceable weight is moved further away from the further main vehicle axle, the load on the further auxiliary wheel increases. If, on the other hand, it is moved closer to the further main vehicle axle, this load decreases. Thus, the control loop is able to vary the load on the further auxiliary wheel so that it is within a range characterized by a lower and an upper limit.
However, the speed of this control loop is limited mainly by the fact that the further displaceable weight takes time to displace. For this, frictional forces must be overcome, as well as the inertial force of the further displaceable weight, which counteracts the displacement force. If, for example, the further work machine is driving on an uneven road surface and impact-like forces are acting on the further wheels of the further main vehicle axle, then the load on the further auxiliary wheel can also decrease impact-like. If this load reaches zero, the vehicle is in danger of tipping over before this load can be increased by moving the further displaceable weight. This can be counteracted by setting the lower limit value for the load high. This means that the height of the lower limit value is also a safeguard against the vehicle tipping over.
In the further work machine according to the invention, in contrast to the work machines of the prior art, the lower limit value can be selected very low, since the further drive units of the further wheels of the further main vehicle axle are used to prevent the vehicle from tipping over if the lower limit value is quickly undershot. By selecting further drive units for this purpose that can change their torque very quickly, as is the case with electric motors, for example, an additional, fast-acting control loop can be created. Similar to the control loop that uses the displacement of the additional displaceable weight to adjust the load on the additional auxiliary wheel, the second control loop uses the change in the torques of the additional drive units to either prevent the vehicle from tipping over when the additional auxiliary wheel is already in the air or when the load on the additional auxiliary wheel moves downwards in a jerky manner so quickly that the movement of the additional displaceable weight, which is too slow for this purpose, cannot prevent the lower limit value from being undershot.
The second control loop can thus be used to compensate for the low control speed of the first control loop, and a vehicle can be created which can be operated in the driving mode auxiliary wheel, and is thus nevertheless very agile and maneuverable on uneven road surfaces. If, for example, the further work machine according to the invention drives on an uneven roadway in the forward direction, i.e. in the direction of the vehicle side opposite to the further auxiliary wheel, and has a substantially constant drive torque applied to the further drive units of the further wheels of the further main vehicle axle, then the further displaceable weight is at a constant position which is adjusted so that the load on the further auxiliary wheel is slightly above the lower limit value. If this further work machine drives through a pothole or a depression in the roadway, for example, the load on the auxiliary wheel decreases abruptly. The load reduction is detected by the load sensors on the further auxiliary wheel and reported to the control system. The further displaceable weight is immediately accelerated and moves to the rear.
Specifications such as front, rear, top and bottom are based on the further work machine used in accordance with the rules, which stands at the bottom on the ground and lifts the further working unit off the ground, for example, and moves it forwards to the front and backwards to the rear.
However, the additional auxiliary wheel can still lift off the ground. The second control loop then superimposes an additional drive torque on the drive torques already applied by the additional drive units, whose level depends on the preceding driving resistances. The higher drive torque causes the further work machine to accelerate forward. This results in a reaction torque at the further drive units, which acts on the further work machine in the direction in which the further work machine wants to tip backwards, or in which the further auxiliary wheel is pressed downwards. This prevents the further work machine from tipping over to the front.
For this second control loop, in addition to the load sensors for the load on the further auxiliary wheel, the tilt sensors provided for the self-balancing control loop can also be used. These detect the tilting motion of the vehicle when the further auxiliary wheel is already off the ground. They also detect whether the higher drive torque causes the vehicle to straighten up again, or whether the superimposed torque needs to be increased even further. Thus, inclination sensors together with the further drive units are part of the control loop in the driving mode auxiliary wheel.
If, for example, the vehicle according to the invention drives backwards, i.e. in the direction of the further auxiliary wheel, and a torque is present in this driving direction, which depends on the driving resistances, then this drive torque must also be changed when driving through a pothole in order to avoid tipping over. In this case, however, the existing drive torque is lowered to obtain the same effect as for forward driving.
In a preferred embodiment of the further work machine according to the invention, this superimposed torque, which prevents the vehicle from tipping over, is applied only until the load on the further auxiliary wheel is again above the lower limit value. Since the further displaceable weight is also displaced backwards at the same time when a value below this limit value is detected, the duration of the superimposed torque can be kept short. Thus, excessive acceleration of the vehicle speed is avoided. Similarly, the position sensors can also be used to determine the time at which the superimposed torque is reversed, as they can indicate that the vehicle has straightened up enough for the further auxiliary wheel to be on the ground again. If the additional auxiliary wheel lifts off or up from the ground, it is guided back to the ground by the superimposed torque. The vehicle therefore only travels briefly on two additional wheels and is immediately returned to the auxiliary wheel driving mode, in which the additional auxiliary wheel is on the ground with a low load. The recurring return of the additional auxiliary wheel to the ground is performed as long as the control unit has a signal that is to keep the vehicle in the auxiliary wheel mode with low load, thus having selected the auxiliary wheel driving mode.
If the corresponding signal is now different, namely that a change to the self-balancing driving mode is to be made, the load on the further auxiliary wheel is reduced by displacing the further displaceable weight until it reaches zero. At the same time, the control loop required for self-balancing using the inclination sensors is now switched on.
In a further preferred embodiment of the further work machine according to the invention, the lower and upper limit values are variable. These can be selected differently, for example, depending on the road conditions or the application. The limit values can be set either by an operator who does this either via a control element on the vehicle or via a remote control. Or the change of the limit values can also be done by automatic functions designed to optimize the respective driving situation.
In another preferred embodiment, the driving speed is used to automatically optimize the limit values. In a further embodiment, the further auxiliary wheel is arranged on the further displaceable weight. This has the advantage that the load on the additional auxiliary wheel does not increase significantly when the additional displaceable weight is extended far backwards. However, it can also be arranged on the rear part of the further vehicle frame.
In a further embodiment, vehicles with displaceable weights are to be used for this purpose. These should be able to be displaced in a sufficiently wide range and thus keep the vehicle's center of gravity in an ideal range. The displacement should be possible without large energy loss. Furthermore, the displacement should be easily controllable. It should run approximately parallel to vehicle longitudinal axis. The displacement device should be simple, inexpensive and robust and should not cause excessive wear on the components used during displacement.
A third work machine according to the invention comprises a third working unit or a third holder for a working unit. Furthermore, the third work machine according to the invention comprises one or more third vehicle axles, wherein third wheel elements and/or caterpillar elements are arranged on both sides of the third vehicle axles. Furthermore, the third work machine according to the invention comprises at least a third displaceable weight, wherein the position of the third displaceable weight is displaceable in such a way that the vehicle center of gravity can be displaced therewith. Furthermore, the third work machine according to the invention comprises at least one rod system for fastening and guiding the third displaceable weight, which comprises at least three rods, a first rod being rotatably mounted on the vehicle/vehicle frame via a first hinge point and a second rod being rotatably mounted on the vehicle/vehicle frame via a second hinge point, and a third rod being rotatably connected to the first rod by a third hinge point and being rotatably connected to the second rod by a fourth hinge point. In this case, the displaceable weight is arranged rotatably or fixedly on the third rod via a fifth hinge point.
The first four hinge points are arranged in such a way that they form a polygon with at least four sides via their connecting lines. The three hinge points of the third rod are connected to each other by a first connecting line and a second connecting line, which are at a fixed angle of more than 90° to each other. The positions of the hinge points of the first and second rods on the vehicle/vehicle frame, the length of the connecting line of the first rod, the length of the connecting line of the second rod, the fixed angle and the lengths of the connecting lines of the three hinge points on the third rod are arranged in such a way that the third rod guides the third displaceable weight during displacement on a substantially straight line fixedly associated with respect to the vehicle.
Thus, in contrast to a prior art work machine, a third work machine according to the invention has a third displaceable weight which is displaceable in a very wide range, with the displacement taking place in a straight line. In a preferred embodiment, the third displaceable weight is driven by only a single drive/actuating element, which, for displacement, must overcome essentially only the forces necessary to accelerate and decelerate the third displaceable weight. The displacement path in the horizontal direction is generated by two rods that are rotatably supported by hinges, so that the two displacement paths in the horizontal direction add up. Thus, this displacement path reaches a substantial length. In this way, the center of gravity of the vehicle can be kept in a range favorable for the stability of the vehicle, even when very dynamic forces act on the vehicle via the working unit. Due to the large displacement path, the third displaceable weight can counteract these forces with a larger lever arm and can thus produce the same effect as in the case of the fixed, and in some cases significantly heavier, counterweights of work machines of the prior art.
The forces acting on the third displaceable weight due to gravity, which can be further increased by dynamic driving conditions, must be transmitted to the vehicle through the hinge points. In the third work machine according to the invention, these forces are transmitted exclusively by simple hinges, which, by a simple rotation, for example by the use of pins, allow the necessary movements to displace the weight. Such hinges can be very robust in their design. They are well protected from dust and dirt ingress, they require little maintenance, and they can ensure long durability. They also cause only comparatively low frictional losses even when transmitting high loads. These can be reduced even further if plain bushings or rolling bearings are used.
In a preferred embodiment, the rod system is arranged in such a way that it guides the third displaceable weight along a line that is arranged substantially parallel to the vehicle longitudinal axis. This gives the advantage that the weight can be displaced a long way without approaching the ground, which would compromise ground clearance, or without having to be raised a long way up, which would consume unnecessary energy and shift the vehicle's center of gravity to a higher position that is less favorable for the vehicle. In a further embodiment, however, this line may be arranged in such a way that, in addition to displacing the third displaceable weight parallel to the vehicle longitudinal axis, thereby causing a displacement of the center of gravity of the vehicle parallel to the vehicle longitudinal axis, a vertical component of movement is simultaneously included.
In a preferred embodiment, the position and length of the displacement path of the third displaceable weight makes it possible to always precisely adjust the vehicle's center of gravity above a single third vehicle axis, so that this machine can balance itself in this way. This makes it possible to steer the vehicle with the third wheels of this axle by driving the third wheels at different speeds or even with different directions of rotation. Such machines can thus be operated in a very maneuverable and agile manner.
In another embodiment, the rod system comprises a fourth rod rotatably connected to the displaceable weight at one end by another hinge point and rotatably connected to the second rod at the other end by another hinge point. Thereby, the second rod has a third hinge point, wherein the three hinge points of the second rod are connected by a first connecting line and a second connecting line, which are at a fixed angle of more than 90° to each other. In this case, the positions of the two hinge points on the displaceable weight, the length of the third rod (by which are to be understood the connecting lines of the hinge points), the length of the fourth rod, the fixed angle and the length of the connecting line of the second rod are arranged in such a way that the fourth rod holds the third displaceable weight in a substantially horizontal position during displacement. This has the advantage that the horizontal position of the third displaceable weight does not change when displaced along the vehicle longitudinal axis. Thus, the displaceable weight may comprise components, such as motors for energy conversion, hydraulic pumps, fluid reservoirs, and/or other storage, drive, or control elements, which can operate without interference and whose function cannot be impaired by any inclined position.
In a preferred embodiment, the third displaceable weight is connected to the vehicle by two rod systems, which are arranged on two sides of the weight in such a way that the third displaceable weight has space between these rod systems and can be displaced between them. This has the advantage that a kind of tramline remains free between the two rod systems, in which the third displaceable weight can be moved back and forth. In this way, the third displaceable weight can move along the vehicle longitudinal axis in a range in which the rods are connected to the vehicle. The advantage is that this can result in very short and compact vehicles.
In a particularly preferred embodiment, the hinges of the rod systems comprise sliding bushings or rolling bearings that reduce the frictional forces generated in the bearing points of the hinges when the third displaceable weight is displaced. Thus, displacement at high dynamics can be performed quickly and without excessive energy consumption.
In a further embodiment, the third work machine comprises a control unit, wherein the control unit comprises at least one electronic control loop and thus controls the position of the third displaceable weight. This control system may comprise, for example, inclination sensors.
In a further embodiment, the third work machine comprises sensors that detect the position of the third displaceable weight. This can be evaluated, for example, in an electronic control unit and used to control or regulate the ideal position of the weight and thus the ideal position of the vehicle's center of gravity. Such sensors can be linear sensors or angular sensors, which, for example, detect an angle between two rods at a hinge point.
In a further embodiment, the third work machine comprises sensors that detect the weight of the third displaceable weight. This can provide load data to an electronic control unit that is variable, for example, by changing the weights of elements located within the third displaceable weight. For example, these may be fuel tanks, or tanks containing hydraulic fluid.
In another embodiment, the displacement is performed by a drive/actuator, which may be, for example, a hydraulic cylinder or an electric linear actuator, or an electric actuator arranged at a hinge point, such as an electric motor with a reduction gear.
In a typical embodiment, the third displaceable weight of the third work machine according to the invention comprises an energy storage device and/or an energy conversion motor. An energy conversion motor may, for example, be an internal combustion engine as known in the prior art. Furthermore, this also includes other known devices for energy conversion, such as hydraulic pumps. The energy storage device may be, for example, an accumulator for storing electrical energy. The energy provided by the energy storage device and/or the motor for energy conversion can be used not only for the traction drive, but also for hydraulic motors and/or pumps for controlling the displacement of the weight or for the movements of the third working unit. This results in the advantage that the weight of, for example, an energy storage device, when displacing the displaceable weight, simultaneously serves to displace the center of gravity. This means that comparatively lightweight vehicles can be produced.
In a preferred embodiment of the third work machine according to the invention, an auxiliary wheel can be arranged on the third displaceable weight. The advantage of such an auxiliary wheel is that it can be used, for example, to absorb load peaks. Such load peaks can arise, for example, when the third work machine is used as a working unit a bucket for breaking off material, for example in a quarry wall, or during unloading of the bucket when the load on the bucket is abruptly reduced by the falling out of material to be loaded. For this purpose, the auxiliary wheel can be used as an additional support element in an embodiment in that the control system allows a small load to be applied to the auxiliary wheel as well, so that the center of gravity is allowed to be displaced outside the third vehicle axle toward the third displaceable weight for a short time (in particular during a loading process). In addition, the auxiliary wheel can prevent the third displaceable weight from hitting the ground as a result of the abrupt displacement of the center of gravity (for example, when unloading the bucket) of the third work machine or from dragging on the ground in the event of such an abruptly required positional displacement. Thus, one advantage of the auxiliary wheel is that it can be used as an additional support point for the third work machine, particularly during loading and unloading, when abrupt load peaks and resulting displacements of the center of gravity can occur. It should be noted, however, that the main load should always be carried by the third vehicle axle, so that the auxiliary wheel and its bearing/suspension in and/or on the counterweight need only be dimensioned for light loads. Furthermore, the auxiliary wheel can prevent, for example, the displaceable weight from touching down on the ground in the event of an emergency braking of the third work machine, in which case the third displaceable weight of the third work machine must be moved abruptly against a direction of travel of the third work machine.
In a further embodiment, the working unit is arranged to the third work machine via a mount which can be rotated about the vertical axis of the vehicle and which thus permits a steering movement of the vehicle. Prior art vehicles are known which can accommodate attachable and detachable working units. In the uncoupled state, the third work machine drives and steers by means of suitable devices, for example, in that one axle has steerable wheels. Alternatively, it can self-balance and steer via different speeds of the wheels on the main axle. If caterpillar drives are arranged on both sides of a main axle, the vehicle also steers via different drive speeds and it stands stable on the caterpillar drives and thus does not require balancing means. If a working unit is coupled to such a vehicle via a rotatable mount, and the working unit has track-retaining devices such as wheels, then steering takes place via this swivel joint. Such steering devices are known from the prior art, for example, in articulated dump trucks, or in articulated wheel loaders. However, track-retaining devices can also be working units, which, as long as they are in working engagement, are guided in a laterally stable manner by means of plowshares or tillage tines.
If such vehicles include a third displaceable weight, for example, the center of gravity of these third working units can be adjusted in such a way as to use only one driven axle, with this vehicle having the same traction capability as prior art vehicles having two or more driven axles. The displaceable weight allows the position of the center of gravity to be adjusted close to the driven axle, with that axle carrying all of the weight available to generate traction. If this support is designed in such a way that it allows movement about the vehicle vertical axis but does not allow movement about the vehicle transverse axis, then a force acting downward on the working unit, for example caused by the tillage equipment such as plowshares, can also be directed to the driven axle by displacing the displaceable weight to the side away from the working unit.
Plows are known from the prior art that have a driven wheel on the side facing away from the tractor. This wheel draws power from the tractor by means of hydraulic pressure oil or by means of electric current. Thus, the force acting downward on the plowshares can be used by this driven wheel to generate a propulsive force, which thus helps the tractor to pull the plow. If a tractor has a displaceable weight, the same pulling force can be generated with the help of the single driven main axle and the driving device on the plow can be saved.
In a further embodiment, trailers can also be coupled to the third work machine according to the invention via this holder, so that the steering function of this vehicle takes place via the swivel joint. Such vehicles can also use the load of the trailer to generate tractive force on the main axle of the third work machine via the third displaceable weight. Trailers are known from the prior art that have a driven axle and in such a way use the trailer load to generate tractive force. The preloaded tractor can thus be built lighter, with the same driving performance. Due to the displaceable weight, such a driven trailer axle can be dispensed with in the third work machines according to the invention.
Further advantages, features and details of the invention result from the following description of preferred embodiment and from the drawing; these show in
A self-steering auxiliary wheel 58 is arranged on the displaceable weight 59. This can take a load as long as the vehicle is outside the self-balancing mode. The load on the auxiliary wheel 58 is changed by a displacement of the displaceable weight 59, which is ideally smaller than the load on the main vehicle axle 56. In such a way, it can be ensured that the wheel elements 57 of the main vehicle axle 56 always have a high contact pressure on the ground and can thus generate sufficient traction. The wheel loader 50.2 comprises two levers 62.1 and 62.2, by means of which the displaceable weight 59 is connected to the vehicle frame 55 and by means of which the adjustment of the position of the displaceable weight 59 is effected.
Two pivot arms 60 and two working arms 61 are respectively arranged on both sides of the vehicle in such a way that the working unit 52 can be pulled backwards, thus ensuring the stability of the vehicle against tipping over to the front. However, this requires the same installation space as the displaceable weight in order to be pulled far towards the main vehicle axle.
The work machine 1.1 according to the invention can be used as a robot. In this case, the machine operates without a driver, i.e. remotely controlled and/or autonomously. Robots, such as those used in agriculture, are often lighter and smaller than the work machines as they are mostly used today. By using several of such robots to perform the work of a single work machine, and by being faster and more agile, they can be smaller and lighter and still deliver the same performance. Advantageously, they have lower manufacturing costs and lower operating costs, as well as being maneuverable and agile.
Furthermore, the work machine 1.1 according to the invention comprises a displaceable weight 5 connected to the vehicle frame 12 via a rod system 11. Here, the rod system 11 is arranged in such a way that the displaceable weight 5 can be displaced in such a wide range so that the displaceable weight 5 can be brought very close to the main vehicle axle 3 and that the vehicle is thus very compact. Due to the wide displaceable range, the displaceable weight 5 can be comparatively small and still compensate for the weight of a heavy working unit 2 via the leverage effect when this is lifted without the vehicle losing its stable position. These rods guide the displaceable weight along the vehicle longitudinal axis 14 in a substantially straight line. Little energy is expended during displacement, since the drive essentially only has to apply the acceleration energy for the displaceable weight.
In a preferred embodiment of the work machine 1.1 according to the invention, the displaceable weight 5 comprises elements such as energy converters, electric batteries or hydraulic systems for supplying the hydraulic cylinders.
Furthermore, the work machine 1.1 according to the invention has pivot arms 6.1 and 6.2 which are rotatably mounted on the vehicle frame 12. Also rotatably mounted on the pivot arms 6.1 and 6.2 are working arms 7.1 and 7.2, which comprise a holder 9 on which a working unit 2 can be arranged.
Since in a preferred embodiment the displaceable weight 5 contains in its interior functional elements such as energy accumulators, energy converters, hydraulic pumps, valves and hydraulic oil accumulators, it takes up a comparatively large extension in the direction of the transverse axis 15 of the vehicle. Ideally, only a single displaceable weight 5 is used, but several smaller ones may well be used, in which case they need not be centered.
In the preferred embodiment, a rod system 11.1 and 11.2 is arranged on each side of the displaceable weight 5, consisting of four rods 18.1, 18.2, 18.3 and 18.4. The rod systems 11.1 and 11.2 are assigned the two second and third movement channels 16.2 and 16.3 to ensure their movements in the direction of the main vehicle axis 3. In the preferred embodiment, the two pivot arms 6.1 and 6.2 and, lying in the same level, the two working arms 7.1 and 7.2 are attached to the vehicle frame 12 further out in the direction of the vehicle transverse axis 15. In this case, the two pivot arms 6.1, 6.2 and the assigned two working arms 7.1, 7.2 move in the same level. The two fourth and fifth movement channels 16.4 and 16.5 are assigned to them. The width of these fourth and fifth movement channels 16.4, 16.5 can thus be kept very small.
Furthermore, the work machine 1.3 according to the invention comprises two displaceable weights 5.1, 5.2. These are connected to the vehicle frame 12 via two rod systems 11.1, 11.2. The rod systems 11.1, 11.2 are arranged in such a way that the displaceable weights 5.1, 5.2 can be displaced over a wide range. This means that they can be moved very close to the main vehicle axle 3, making the vehicle very compact. Due to the wide displaceable range, the displaceable weights 5.1, 5.2 can be comparatively small and still compensate for the weight of a heavy working unit 2 via the leverage effect when this is lifted without the vehicle losing its stable position.
On both sides of the pivot arm 6 and the working arm 7, a rod system 11.1 and 11.2 are arranged in the preferred embodiment. The two rod systems 11.1 and 11.2 are assigned the two seventh and eighth movement channels 16.7 and 16.8 to ensure their mobility in the direction of the main vehicle axis. In the preferred embodiment, the displaceable weights 5.1 and 5.2 are arranged further out in the direction of the vehicle transverse axis 15. In this case, the displaceable weights 5.1 and 5.2 move in the two ninth and tenth movement channels 16.9 and 16.10 assigned to them. This has the advantage that the displaceable weights 5.1, 5.2 can be pulled far towards the area of the main vehicle axle 3. Since the sixth movement channel 16.6 is for the first pivot arm 6 and the first working arm 7, the two seventh and eighth movement channels 16.7 and 16.8 are for the rod systems 11.1 and 11.2, and the two ninth and tenth movement channels 16.9 and 16.10 for the displaceable weights 5.1 and 5.2 do not interfere with each other, the working unit 2 and the displaceable weights 5.1 and 5.2 can be pulled toward the center of the vehicle at the same time, resulting in a very compact overall length of the vehicle. Due to the short overall length, very agile and fast movements of the vehicle are achieved.
In a preferred embodiment of the work machine 1.3 according to the invention, the two displaceable weights 5.1, 5.2 are fixedly connected to each other at their rear end. This allows them to be moved by a single drive element or a single actuating element. Since the connecting elements of the two displaceable weights 5.1, 5.2 are arranged at the rear end of the vehicle, or at the rear end of the weights 5.1, 5.2, the movements of the pivot arm 6 and the working arm 7 as well as the rod systems 11.1, 11.2 are not disturbed.
In
In
Furthermore, the further work machine 101 according to the invention comprises a further displaceable weight 105, which is connected to the further vehicle frame 113 via a further rod system 112. Thereby, the further rod system 112 is arranged in such a way that the further displaceable weight 105 can be displaced in such a wide range so that this can be brought very close to the further main vehicle axle 103 and that the vehicle is thus very compact. Due to the wide displaceable range, the further displaceable weight 105 can be comparatively small and can nevertheless compensate for the weight of a heavy further working unit 102 via the leverage effect when the said working unit is lifted without the vehicle losing its stable position.
In a preferred embodiment of the further work machine 101 according to the invention, the further displaceable weight 105 comprises elements, such as energy converters, electric batteries or hydraulic systems for supplying the hydraulic cylinders.
Furthermore, the further work machine 101 according to the invention has further pivot arms 107, and further working arms 108, with which the further work unit 102 can be moved. An auxiliary wheel 106 is arranged on the further displaceable weight 105, which is rotatably mounted in such a way that it can make passive steering movements. The steering movements of the further work machine 101 according to the invention are made by the different speeds or directions of rotation of the further drive units 109, which drive the further wheels 104 arranged at both outer ends of the further main vehicle axle 103. Thus, the further work machine 101 can be operated in a very maneuverable and agile manner. In this case, the auxiliary wheel 6 can either be in the air. Then the further work machine 101 balances around the further main vehicle axle 103. Or the auxiliary wheel 106 is in contact with the ground, in which case it takes up a significantly lower load than the further wheels 104 of the further main vehicle axle 103. The steering movements predefined by the further drive units 109 then automatically lead to a rotation of the auxiliary wheel 106, whereby the latter is passively steered as well.
Furthermore, the holder of the auxiliary wheel 106 on the further displaceable weight 105 comprises at least one load sensor, which can measure the load, i.e. the force, acting between the ground and the auxiliary wheel. In a further embodiment, this force can also be measured at any point of the further rod system 112, in which case the weight of the displaceable weight can be taken into account.
In a further embodiment, the holder of the auxiliary wheel 106 may comprise a device for moving the auxiliary wheel upwardly in relation to the further displaceable weight 105 or in relation to the further vehicle frame 113. This increases the distance between the roadway and the auxiliary wheel 106 when balanced about the further main vehicle axis 103.
The further work machine 101 according to the invention can be operated by means of at least two driving modes. In the driving mode self-balancing, the auxiliary wheel 106 is load-free and/or is in the air. Thus, it has no contact with the roadway. The control of the further work machine 101 comprises a control loop that comprises inclination sensors, that controls the drive units 109, and that controls the further displaceable weight 105. A further driving mode, the auxiliary wheel driving mode, is that the control comprises a control loop that comprises inclination sensors and that further comprises load sensors on the auxiliary wheel, and that controls the further displaceable weight 105 and the further drive units 109. This control circuit controls the position of the further displaceable weight 105 in such a way that the load on the auxiliary wheel 106 adjusts itself above a lower limit value and below an upper limit value.
These limit values are set in such a way that the upper limit value, causes a significantly lower load on the auxiliary wheel than on the further wheels 104 of the further main vehicle axle 103. Since only these further wheels 104 have the further drive units 109, the largest proportion of the vehicle weight can thus be used to generate traction. In contrast to prior art work machines comprising four or more driven wheels, the further work machine 101 according to the invention is able to provide the same traction with only two driven wheel elements. In addition, the low load provided by the upper limit causes the further work machine 101 to have good steerability, and the lower limit is set in such a way as to prevent the further work machine 101 from tipping over to the front when driving on difficult terrain or uneven road surfaces. It is taken into account that the displacement of the further displaceable weight 105 has a reaction time, which is predetermined, by the speed of the control loop as well as the acceleration and movement speed of the further displaceable weight 105. If the lower limit value is high, then the further work machine 101 does not yet tip over when the speed falls below the lower limit value. Thus, more time is available to the control loop. In the further work machine 101 according to the invention; however, the lower limit value is selected to be low. In a preferred embodiment, this is essentially close to zero. In this case, the control loop controls the drive units with significantly less reaction time in such a way that tipping over of the further work machine 101 is thereby prevented. This is done, for example, during forward driving by increasing the drive torque of the further work machines 109. Since in a preferred embodiment of the work machine according to the invention electric motors are used as further drive units 109, which have very short reaction times for increasing their torque, the total reaction time of this control loop is also very short. Due to the higher torque, the work machine, when tipping over, can be straightened up quickly until the auxiliary wheel 106 is back on the ground. This control loop uses not only the signals from the load sensors on the auxiliary wheel 106, but also the tilt sensors, which provide usable signals even when the auxiliary wheel is already in the air. The goal of the control loop in this driving mode auxiliary wheel is not driving on two wheels, but on at least three. Therefore, if the auxiliary wheel lifts off the ground, the amount of superimposed torque on the other drive units 109 is selected in such a way that the auxiliary wheel is returned to the ground. Similarly, the time at which the further drive units 109 have an increased torque is limited to such an extent that the auxiliary wheel 106 is loaded again as quickly as possible, but without hitting the ground too hard.
The setting of the lower and upper limit value can be done either manually by an operator using either a control element or by a remote control. However, this setting can also be done by an automatic function of the control system. For example, the driving speed can be pulled for this purpose. The selection of one of the two modes can likewise be controlled either manually by an operator, for example using an operating element or a radio remote control, or by an automatic function of the control. This can, for example, take into account the driving speed, whereby at higher driving speeds, the self-balancing driving mode is more likely to be selected and at slower driving speeds the auxiliary wheel driving mode is more likely to be selected. However, other variables can also be taken into account for these specifications. For example, GPS data can identify the location of the work machine. If the machine has already been operated at the same location at an earlier time and the unevenness of the ground at this location was very great, the limit values and the switchover to the auxiliary wheel driving mode can be predefined. To detect the unevenness, sensors suitable for this purpose can also be used, such as the inclination sensors or acceleration sensors.
Furthermore, the wheel loader 250.2 comprises as working unit 252 a bucket which is connected to the vehicle frame 256 via the working arms 255.1 and 255.2. On the vehicle side facing away from the working unit 252, the work machine 250.2 has a displaceable weight 259 with which the vehicle center of gravity can be displaced and which can thus always be leveled above the main vehicle axle 253. By displacing the displaceable weight 259, the vehicle can be controlled in its directions of movement in self-balancing mode. A self-steering auxiliary wheel 257 is arranged on the displaceable weight 259. This can take up a load as long as the vehicle is outside the self-balancing mode. The load on the auxiliary wheel 257 is changed by a displacement of the displaceable weight 259, which is ideally smaller than the load on the main vehicle axle 253. In such a way, it can be ensured that the wheel elements 254 of the main vehicle axle 253 always have a high contact pressure on the ground and can thus generate sufficient traction.
The wheel loader 250.2 comprises two levers 258.1 and 258.2, via which the displaceable weight 259 is connected to the vehicle frame and via which the adjustment of the position of the displaceable weight 259 is effected. The two levers 258.1 and 258.9 of the wheel loader 250.2 each require their own drive, such as a hydraulic cylinder or an electric actuator. The drives are not shown in
The levers 258.1 and 258.2 of the wheel loader 250.2 can be arranged centrally on the vehicle. In this case, the lever 258.1 is arranged far forward on the vehicle frame 256. The displaceable weight 259 can thereby be moved forward in such a way until it collides with the lever 258.1. Lever 258.1 thus limits the movement of displaceable weight 259 to the front. Thus, self-balancing can only occur if the working unit 252 is not pulled very far backwards, which means that the vehicle length cannot be reduced significantly. This disadvantage can be overcome by arranging the levers 258.1 and 258.2 laterally on the displaceable weight 259. Then the levers 258.1 and 258.2 are each required on both sides of the displaceable weight 259. A tramline is thus kept free in the center of the vehicle for the displaceable weight 259, allowing it to be displaced further to the front. However, such an embodiment can have the result that these levers 258.1 and 258.2 each require their own drive on both sides of the vehicle, which has a negative effect on the cost and weight for the vehicle.
In order to keep the displaceable weight 259 freely in the air against gravity, as is necessary for example in self-balancing mode, or to keep the load on the auxiliary wheel 257 low even during dynamic work processes, the levers 258.1 and 258.2 must be able to carry high loads. The same applies to the drives of the same. The drives must also move the displaceable weight 259 quickly and dynamically. At the same time, however, in addition to these dynamic loads, the steady load on the levers 258.1 and 258.2 and the drives is also created by the gravitational force acting on the displaceable weight. If hydraulic cylinders are used as actuators, which are comparatively robust and inexpensive, the pressure applied in the piston chamber will be permanently high, influenced by the load of the displaceable weight, even as long as there is no movement of the displaceable weight. If a movement is now requested by the control unit, additional hydraulic oil is pumped into the piston chamber, which must then be pre-pressurized in advance by a pump or from an accumulator element to at least the same pressure as is present in the piston chamber. This requires considerably more energy than would be needed to accelerate the displaceable weight alone. As a result, these drives are not very energy efficient. Thus, the wheel loader 250.2 comprises at least three drives/actuators, each of which is controlled independently of the others, which means that independent position sensors are also required. This means that a complex control system is required.
The third work machine 201.1 according to the invention can be used as a swarm robot. In this case, the machine operates without a driver, i.e. remotely controlled and/or autonomously. Swarm robots, such as those used in agriculture, are often lighter and smaller than tractors as they are mostly used today. By using several such swarm robots to perform the work of a single tractor, they can be smaller and lighter and still provide the same performance. The advantage here is that the smaller vehicle weights result in much lower soil compaction. The high soil compaction of today's tractors is often disadvantageous for agricultural soils.
Furthermore, the third work machine 201.1 according to the invention comprises a third displaceable weight 205, which is connected to the vehicle frame 215 via a rod system 206.1. Thereby, the rod system 206.1 is arranged in such a way that the third displaceable weight 205 can be displaced in such a wide range that it is neither substantially raised nor lowered and that the displacement path substantially replicates a straight line 216. Due to the wide displaceable range, the displaceable weight 205 can be comparatively small and still compensate for the weight of a heavy working unit 202.1 via the leverage effect when the said working unit is lifted.
In the third work machine 201.1 according to the invention, the third displaceable weight 205 exclusively comprises elements, such as an electric accumulator, for which it is not necessary to maintain the horizontal position. It may be fixedly attached to the rod 207.3 so that it rotates with the same angle with respect to the horizontal position as the rod 207.3 itself. The third displaceable weight 205 is shown as a circle by way of example, although it may also be cylindrical in shape. However, it can just as well take any other design.
With the rod system 206.1 of the work machine 201.1 according to the invention, the third displaceable weight 205 can be displaced with a single drive/actuating element 225.1, which is arranged, for example, in the center of the vehicle. Of course, two or more drives can also be used. The drive/actuating element 225.1 does not absorb any forces needed to hold the displaceable weight up against gravity, but only forces needed to accelerate and decelerate the weight 205, including frictional forces of the hinges that counteract movement of the third displaceable weight 205. The hinge points 208.1, 208.2, 208.3 and 208.4 are simple pin joints which can be designed to be low friction, very robust, low wear, easy to maintain and comparatively inexpensive. By design, such hinges can be well protected from dirt and dust ingress. Thus, the rod system 206.1 provides a cost-effective and energy-efficient solution for fastening and guiding the third displaceable weight 205.
For example, these sizes can be selected in such a way that the positions of the hinge points 208.1 and 208.2 are on a line parallel to the vehicle longitudinal axis. Their connecting line 209.4 is 0.4 meters long. The connecting line 209.1 of the first rod 207.1 is 1.60 meters long, and the connecting line 209.2 of the second rod 207.2 is 1.45 meters long. Then, for the third rod 207.3, the connecting line 209.5 is 0.2 meters long, and the connecting line 209.3 is 1.30 meters long, wherein these are at a fixed angle 217.1 of 140° to each other. In this embodiment, the hinge point 208.5 displaces along a substantially straight line 216 for a distance 218.3 of about 2.5 meters, which is substantially parallel to the connecting line 209.4 and thus the third displaceable weight 205 can be displaced parallel to the vehicle longitudinal axis. The determination of these quantities as well as their dependence on each other can be done by graphical methods, as shown in
With the rod system 206.2 of the third work machine 201.2, the third displaceable weight 205.1 can be displaced with a single drive/actuating element 225, which is arranged, for example, in the center of the vehicle wherein the fourth rod 207.4 holds the third displaceable weight 205.1 in its horizontal position. This results in the advantage that the third displaceable weight 205.1 can contain elements, such as motors for energy conversion, hydraulic pumps, fluid reservoirs and/or further storage, drive or control elements, which can operate without malfunction and whose function cannot be impaired by any inclined position. Further, an auxiliary wheel 210 may thus be attached to the displaceable weight 205.1, which may include a load sensing device.
Exemplarily, these variables may be selected in such a way that the positions of the hinge points 208.1 and 208.2 are on a line parallel to the vehicle longitudinal axis. Their connecting line 209.4 is 0.4 meters long. The connecting line 209.1 of the first rod 207.1 is 1.60 meters long, and the connecting line 209.2 of the second rod 207.2 is 1.45 meters long. The connecting line 209.6 of the second rod 207.2 is 0.2 meters long and the fixed angle 217.6 of the second rod 207.2 is 150°. Then, for the third rod 207.3, the connecting line 209.5 is 0.2 meters long, and the connecting line 209.3 is 1.30 meters, wherein they are at a fixed angle 217.1 of 140° to each other. The hinge points 208.5 and 208.7 have a horizontal distance 226.1 of 0.34 meters and a vertical distance 226.2 of 0.2 meters. In this embodiment, the hinge point 208.5 displaces along a substantially straight line 216 for a distance 218.3 of about 2.5 meters that is substantially parallel to the connecting line 209.4, allowing the third displaceable weight 205.1 to be displaced parallel to the vehicle longitudinal axis. maintains the third displaceable weight 205.1 in a substantially horizontal position. The determination of these variables as well as their dependence on each other can be done by graphical methods, as shown in
Another advantage is that the holder 224 for a working unit 202.3 allows the trailer 228 to be coupled and uncoupled. Then the work machine 201.3 can be provided as a universal working unit, which can use the most diverse working units as used in construction and agriculture. If the different rotational speed or direction of rotation of the wheel elements 204 arranged on the vehicle axle 203 is used for steering, a very maneuverable and easily maneuverable vehicle is thus created, which thus has advantages even if no working unit 202.3 is attached. In order to be able to couple working units 202.3, for example a trailer 228, very easily and quickly, sensors can be used which, together with an electronic control unit, which has driver assistance systems, automatically, quickly and precisely guide the working unit 201.3 to the working unit.
Further, the third work machine 201.3 can be used with a trailer 228 in earthmoving operations in such a way that the trailer 228 is loaded while uncoupled from the third work unit 201.3. Meanwhile, the third work machine 201.3 with another trailer 228 is traveling along its intended route and does not need to wait for the loading operation. It is often the case that several dump trucks are in use between the loading point and the unloading point. For reasons of efficiency, the loading machine, for example an excavator or a wheel loader, should not have to wait until the next empty dump truck arrives. Therefore, it is often planned in such a way that the number of dump trucks used is higher than absolutely necessary. They may then have to wait at the loading point. For example, if a job site requires a certain number of dump trucks to be operated efficiently, using third work machines 201.3 is sufficient to accomplish the same task with the same number of trailers 228 but with fewer work machines 201.3. By using the displaceable weight 205.2 and the holder 224 to couple the trailers 228, these machines can be used in places where the terrain is very difficult and requires the dump trucks to have a high traction capacity.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2020 125 036.3 | Sep 2020 | DE | national |
| 10 2020 125 042.8 | Sep 2020 | DE | national |
| 10 2020 125 047.9 | Sep 2020 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/076382 | 9/24/2021 | WO |
