Patent Description:
According to prior art, cranes are used which are swivelling and comprise telescopic booms. Cranes are mounted on vehicles, such as trucks, or on other self-propelled machines, such as forwarders. Cranes are used, for example, for loading, and as so-called loader cranes.

Said crane may also be placed in a towable trailer which is equipped with wheels and which also comprises a power source apparatus for the crane, for example a combustion engine, and a control system for controlling the functions of the crane. The control system is typically based on a hydraulic power generation system. In addition to the trailer, the crane typically also comprises outriggers which are connected to the trailer and may be placed in a position where they support and stabilize the crane during its operation. The control system may comprise a control device, by which the operator may remotely control the functions of the crane or its boom, for example in a wireless manner, so that there is no need to provide the trailer with a cabin, a seat, or a station with control devices for the operator.

The boom of the crane may consist of one or more boom sections. Typically, the end of the boom is equipped with a hook for suspending loads to be transferred, or a tool for transferring loads or objects. It is also possible to connect a man cage or a scaffold to the end of the boom, for a worker.

Cranes mounted on vehicles and machines become large, and thereby possibilities to use them in, for example, confined indoor spaces and buildings turn out to be very limited. Also, exhaust gases from the vehicles and machines may pose a problem. It may be difficult to move cranes mounted on trailers manually indoors, and it is not even possible to use a towing vehicle or machine in confined indoor spaces, buildings, or on different floors of a building. Furthermore, bringing a crane mounted on a trailer to the work site may be very difficult or impossible, for example due to the difficult terrain or location of the site.

<CIT> discloses a a mobile loader crane according to the preamble of claim <NUM>, having an elongated rectangular frame supported at each end by a tracked drive unit which provides zero turn capability to the machine. A telescopic boom is pivotally mounted on the upper end of a rotatable pedestal which extends upwardly from the center of the frame. A counterweight support is provided on said pedestal to enable counterweights to be supported directly thereon to counter the weight of said boom arm assembly and the slat supported thereby. The counterweights are selectively removably mounted on said counterweight support.

The solution for a mobile crane is presented in claim <NUM>. Other claims present some other, more detailed examples of said mobile crane according to the solution.

The presented mobile crane comprises a column structure and a telescopic boom configured to move up and down, whereby it is suitable for lifting and transferring loads connected to or suspended from the boom. The crane may be a so-called loader crane. The boom is connected to the column structure by articulation. The crane comprises a turning device, on which the column structure is mounted, and which is configured to turn the column structure and the boom together in two lateral directions, around a substantially vertical direction. The crane comprises at least two or preferably two movable outriggers which can be placed against the ground or a floor and which are configured to support and stabilize the crane.

The crane comprises a control system which is configured to control the functions of the crane and which comprises at least one control device, by which an operator may manually control the functions of the crane. The crane comprises at least one power source apparatus for generating the power needed for the functions of the crane.

According to the solution presented, the crane also comprises a crawler frame for moving the crane and comprising a frame structure and motorized first and second crawler tracks arranged on opposite sides of the frame structure. Furthermore, the crane comprises a turning device mounted on the frame structure of the crawler frame, and the above-mentioned outriggers are connected to the frame structure of the crawler frame.

In particular, the crane according to the presented solution also comprises a counterweight arrangement connected to the column structure. Thus, the counterweight arrangement is configured to turn together with the column structure and the boom around said direction, and furthermore, the counterweight arrangement is suitable for use as a counterweight for the boom and/or loads to be connected to or suspended from the boom.

The crawler frame has the advantage that the crane may move on a terrain and on difficult work sites. The terrain may have slopes or roughness which may be crossed by the crawler tracks. Because the crane comprises its own power source apparatus and a crawler frame for moving, it is self-propelled and movable by itself to or on the work site.

The crane becomes compact as it is not equipped with a cabin, a seat or a station for an operator. Preferably, the functions of the crane may be remote controlled. By means of the outriggers, the frame structure of the crawler frame can be kept compact, because the outriggers extending far from the frame structure stabilize the crane to a sufficient extent.

The counterweight arrangement connected to the column structure of the crane makes it possible that the counterweight arrangement swivels with the boom and acts as a counterweight irrespective of the direction of swivelling of the boom. Preferably, the counterweight arrangement is arranged primarily or entirely on the side of the column structure opposite to the boom, when their placement is seen in the horizontal direction.

In an example, the horizontal distance between the counterweight arrangement and the column structure is adjustable. Thus, the counterweight arrangement may be transferred farther away from and back towards the column structure, for example by means of at least one controllable actuator. Advantageously, the structure of the crane can be made compact, for example for transport, when the counterweight arrangement is retracted. The counterweight arrangement is more effective as a counterweight when it is moved away from the column structure, causing a torque which is opposite to the torque produced by the boom. In an example, the position of the counterweight arrangement is adjustable in the height direction.

In particular, the crane according to the presented solution also comprises at least one of the power source apparatuses of the crane is placed in the counterweight arrangement. In a first example, the power source apparatus comprises either an electric motor or a combustion engine, or both. In a second example, the power source apparatus further comprises an electric generator for generating an electric current. In a third example, the control system of the crane comprises at least one hydraulic pump configured to generate hydraulic power and hydraulic fluid flow, and connected to said power source apparatus; at least one controllable control valve configured to control the hydraulic fluid flow for implementing the functions of the crane; and at least one tank for containing hydraulic fluid. According to said example, one or more of: said hydraulic pump, said control valve, and said tank, is placed in the counterweight arrangement.

The above examples have the advantage that their weight can be utilized as counterweight, to avoid adding such mass in the crane which acts as counterweight only. For example, by placing the power source apparatus in the counterweight arrangement, one avoids adding a corresponding weight in the crane, whereby it is possible to restrict increasing the weight of the crane. A corresponding principle also applies to the hydraulic manifold block of the control system, to which one or more of said control valves to be controlled is connected, as well as to the electrical center of the control system.

In an example, the crane further comprises at least one movable dozer blade which is configured e.g. to move up and down, and is connected to the crawler frame. In another example, the crane further comprises at least one motorized cable winch connected to the crawler frame.

In the following, the presented solution and its different alternatives or examples, as well as combinations of them, will be described with reference to the appended drawings.

A mobile crane <NUM> according to the presented solution and shown in <FIG> may comprise a column structure <NUM>, a boom <NUM>, a turning device <NUM>, at least two movable outriggers <NUM>, a control system <NUM> (see <FIG>), at least one power source apparatus <NUM>, a crawler frame <NUM>, and a counterweight arrangement <NUM>.

The boom <NUM> comprises one or more boom sections <NUM>, <NUM>. Two or more boom sections <NUM>, <NUM> may be placed one after the other and be connected to each other by articulation. Thus, the boom may be a so-called articulated boom, which is foldable to a compact position. In an example and as shown in <FIG>, the boom <NUM> comprises a first boom section <NUM> and a second boom section <NUM>. In an alternative, the boom <NUM> comprises only one boom section <NUM>. In this case, it may be a so-called straight boom.

The column structure <NUM> is substantially or almost vertical, or placed in a tilted position. The column structure <NUM> extends upwards from the top of the turning device <NUM>.

The boom section <NUM> is connected on the column structure <NUM> by articulation and is configured to move up and down, for example by means of a linear actuator <NUM>, such as a hydraulic cylinder. For example, the linear actuator <NUM> is connected between the column structure <NUM> and the boom section <NUM>. The boom section <NUM> pivots about a substantially horizontal direction which is simultaneously transverse to the longitudinal direction of the boom section <NUM>.

The boom section <NUM> is connected to the boom section <NUM> by articulation and is configured to move up and down, for example by means of a linear actuator <NUM>, such as a hydraulic cylinder. For example, the linear actuator <NUM> is connected between the second boom section <NUM> and the first boom section <NUM>. The boom section <NUM> pivots about a substantially horizontal direction which is simultaneously transverse to the longitudinal direction of the boom section <NUM>.

According to the above-mentioned alternative of the crane <NUM>, the boom section <NUM> is directly connected to the column structure <NUM> by articulation and is configured to move up and down, for example by means of a linear actuator <NUM>, such as a hydraulic cylinder. For example, the linear actuator <NUM> is connected between the column structure <NUM> and the boom section <NUM>. The boom section <NUM> pivots about a substantially horizontal direction which is also transverse to the longitudinal direction of the boom section <NUM>.

According to an example and <FIG>, the boom section <NUM> is telescopic for increasing the reach of the boom <NUM>. This may also be the case in the above-mentioned examples and alternatives. For implementing the telescopic feature, the boom section <NUM> may comprise one or more actuators utilizing hydraulic power, for example a linear actuator, such as a hydraulic cylinder.

The boom section <NUM> may comprise several boom sections placed within each other and moving in a telescopic manner with respect to each other, for example assisted by an actuator.

The boom <NUM> is configured to lift and transfer loads connected to or suspended from it, for which purpose the end of the boom section <NUM> may be equipped with a hook, a tool, or a man cage or a scaffold for a worker.

The column structure <NUM> is mounted on top of the turning device <NUM>. The turning device <NUM> is configured to turn the column structure <NUM> and thereby the boom <NUM> in two lateral directions having opposite directions of rotation. The turning device <NUM> turns the column structure <NUM> around a substantially vertical direction. The rotating movement effected by the turning device <NUM> defines an imaginary rotation axis X which is substantially vertical. Preferably, said rotation axis X extends through the turning device <NUM>, substantially its center, and through the column structure <NUM>.

In <FIG>, broken lines illustrate the position of the boom <NUM> when the boom sections <NUM>, <NUM> are in a use position and extend outwards from the column structure <NUM> and thereby outwards from the counterweight arrangement <NUM>.

For implementing the rotation and in an example, the turning device <NUM> may comprise one or more actuators utilizing hydraulic power, for example a linear actuator, such as a hydraulic cylinder, or a hydraulic motor.

The crawler frame <NUM> is provided for moving the crane <NUM>, and it may comprise a frame structure <NUM> and motorized first <NUM> and second <NUM> crawler tracks placed on opposite sides of the frame structure <NUM>.

The turning device <NUM> is mounted on top of the frame structure <NUM> of the crawler frame <NUM>.

The crawler tracks <NUM>, <NUM> may be implemented by means of flexible and elastic rubber rollers. Alternatively, the crawler tracks <NUM>, <NUM> may be implemented by means of steel track pads.

For propelling the crane <NUM>, the crawler tracks <NUM>, <NUM> may be provided with one or more hydraulic motors driven by hydraulic power and rotating the crawler tracks <NUM>, <NUM>.

At least two, or preferably four, movable outriggers <NUM> are mounted on the frame structure <NUM>. Each outrigger <NUM> can be placed against the ground or the floor to constitute a point of support between the outrigger <NUM> and the ground/floor, the outrigger <NUM> being configured to support and stabilize the boom <NUM>. Preferably, at least one pair of outriggers <NUM> can be placed so that at least one point of support is provided on either side of the frame structure <NUM>, at a distance from the frame structure <NUM> and the crawler tracks <NUM>, <NUM>. Said points of support are preferably placed on that side of the frame structure <NUM>, on which the boom <NUM> is working. Said four outriggers <NUM> may be placed on different sides of the frame structure <NUM>, for example at its corners.

Each outrigger <NUM> is connected to the frame structure <NUM>, for example by articulation. According to an example and <FIG>, the outrigger <NUM> may consist of two or more sections connected to each other by articulation. To increase the reach of the outrigger <NUM>, the outrigger <NUM> may function in a telescopic manner, as shown in the example of <FIG>. Each outrigger <NUM> may be transferred to a first position (see <FIG>) in which it is not placed against the ground or floor, and locked into a second position (see <FIG>) in which the outrigger <NUM> is placed against the ground or floor. Said first position is used, for example, during transfer or transportation of the crane <NUM>.

For implementing the movements and the locking of the outrigger <NUM>, the outrigger <NUM> may comprise one or more actuators driven by hydraulic power, for example a linear actuator, such as a hydraulic cylinder, as shown in the example of <FIG>.

According to an example and <FIG>, one or more outriggers <NUM> may be removed from the frame structure <NUM>, for example by quick release members. In this way, the mass of the crane <NUM> becomes lighter and the structure becomes more compact, in case this is necessary for transporting or moving the crane <NUM>.

The control system <NUM> is configured to control the functions of the crane <NUM>, and the control system <NUM> comprises at least one control device <NUM>, by which the operator of the crane <NUM> may manually control the functions of the crane <NUM>.

Said functions include, for example, at least the lifting and lowering of one or more boom sections <NUM>, <NUM>, the turning of the boom <NUM> by the turning device <NUM>, the movement of the outriggers <NUM>, and the movement of the crane <NUM> by means of the crawler frame <NUM>.

The control system <NUM> may be based on components, control means and control circuits utilizing at least partly electric energy or hydraulic energy for implementing said functions. If necessary, the control system <NUM> may also monitor said functions, for example by means of signals given or measurements taken by sensors in the crane <NUM>. The control system <NUM> may comprise a computer based implementation based on control implemented by a stored computer program, programmable logics, or alternatively electronic control based on a computer processor, a memory, and stored algorithms.

The control system <NUM> may comprise at least one hydraulic pump <NUM>, at least one controllable control valve <NUM>, and/or at least one tank <NUM> for containing hydraulic fluid.

The hydraulic pump <NUM> generates hydraulic power and hydraulic fluid flow, and it is connected to the power source apparatus <NUM>. The control valve <NUM> controls the flow of hydraulic fluid for implementing the functions of the crane <NUM>. According to some examples, the flow of hydraulic fluid is utilized in at least one hydraulic cylinder and/or hydraulic motor for the boom <NUM>, the turning device <NUM>, at least one outrigger <NUM>, and/or the crawler frame <NUM>.

At least one control device <NUM> which is available to the operator of the crane <NUM> is connected to the control system <NUM>. The control device <NUM> is e.g. a control panel, a control stick, or a computer based control device. The data transmission between the control system <NUM> and the control device <NUM> may be based on wireless communication and be implemented by e.g. radio control. The wireless communication is implemented by means of e.g. transmitters and receivers.

The crane <NUM> comprises at least one power source apparatus <NUM> configured to generate power needed by the functions of the crane <NUM>. Said power is one or more of the following: mechanical power, electric power, or hydraulic power.

Preferably, the power source apparatus <NUM> is configured to generate at least hydraulic power which is utilized in at least one hydraulic cylinder and/or hydraulic motor for the boom <NUM>, the turning device <NUM>, at least one outrigger <NUM>, and/or the crawler frame <NUM>. For generating the hydraulic power, the power source apparatus <NUM> comprises, for example, a combustion engine, such as a diesel engine, and/or an electric motor.

The power source apparatus <NUM> may comprise a combustion engine <NUM>, such as a diesel engine, and/or an electric motor <NUM>. According to an example and <FIG>, the power source apparatus <NUM> comprises both a combustion engine <NUM>, such as a diesel engine, and an electric motor <NUM>, so that the possibilities of using the crane <NUM> would be versatile and the crane could be used indoors as well, thanks to the electric motor <NUM>. For driving the electric motor <NUM> of the crane <NUM>, the electric motor <NUM> can be connected to an external electric power source separate from the crane <NUM>, for example to an electric network.

According to an example and <FIG>, the power source apparatus <NUM> may comprise an electric generator <NUM> for producing an electric current. The electric generator <NUM> may comprise an output for electric current, which may be utilized on the site where the crane <NUM> is placed. In addition or alternatively, the electric current produced by the electric generator <NUM> is utilized in the electric motor <NUM>, to which a hydraulic pump <NUM> may be coupled.

The electric generator <NUM> may be connected to the power source apparatus <NUM> placed in the counterweight arrangement <NUM>, the electric generator <NUM> thus constituting a part of the counterweight arrangement. The electric generator <NUM> may be connected to the combustion engine <NUM>.

According to the presented solution and <FIG>, the counterweight arrangement <NUM> of the crane <NUM> is connected to the column structure <NUM> of the boom <NUM>, whereby the counterweight arrangement <NUM> is configured to pivot together with the boom <NUM> about the rotation axis X. The counterweight arrangement <NUM>, particularly its mass including parts, devices, structures, and components therein, acts as a counterweight for the boom section <NUM> and/or loads to be connected to or suspended from it, which may also include various tools.

The counterweight arrangement <NUM> is placed, preferably and primarily, on the side opposite the column structure <NUM> and the rotation axis X, that is, on the rear side in relation to the boom section <NUM> placed on the front side, seen in the horizontal direction. The mass of the counterweight arrangement <NUM> causes a first torque effective on the column structure <NUM> and opposite to a second torque effective on the column structure <NUM> and caused by the mass of the boom section <NUM>. The first and second torques may be unequal, and the first torque may compensate for the second torque, at least partly. The loads suspended from the boom section <NUM> increase said second torque.

In an example, the horizontal distance between the counterweight arrangement <NUM> and the column structure <NUM> is adjustable, whereby the counterweight arrangement <NUM> can be transferred farther away from the column structure <NUM>, in which case said first torque increases, and back towards the column structure <NUM>, in which case said first torque decreases, or the structure of the crane <NUM> can be made compact, for example for transport. When said distance increases, the counterweight arrangement <NUM> moves rearwards, away from the boom section <NUM>. For adjusting and setting said distance, the counterweight arrangement <NUM> may comprise at least one controllable actuator, for example a linear actuator, such as a hydraulic cylinder driven by hydraulic power.

According to an example and <FIG>, the counterweight arrangement <NUM> may comprise a scaffold <NUM>, to which the parts, devices, structures, and components of the counterweight arrangement <NUM> are fastened and which, in turn, is fastened to the column structure <NUM>. Said scaffold <NUM> may be movable, for example for adjusting the distance, or it may have a subassembly by means of which said parts, devices, structures, and components can be moved farther away from the column structure <NUM>.

In <FIG> and according to the invention, at least one above mentioned power source apparatus <NUM> is placed in the counterweight arrangement <NUM>. Said power source apparatus <NUM> comprises a combustion engine <NUM>, such as a diesel engine, or an electric motor <NUM>, or both, as described in the different examples relating to the power source apparatus <NUM> in the above description.

According to another example and <FIG>, one or more of: at least one hydraulic pump <NUM>, at least one control valve <NUM>, at least one tank <NUM> for containing hydraulic fluid - as described in the different examples relating to the control system in the above description - are placed in the counterweight arrangement <NUM>.

The control valve <NUM> may be fastened to a valve manifold block comprising channels for hydraulic fluid. Said valve manifold block may be placed in the counterweight arrangement <NUM>.

According to an example and <FIG>, one hydraulic pump <NUM> is connected to a combustion engine <NUM> and another hydraulic pump <NUM> is connected to an electric motor <NUM>, and furthermore, they are all placed in the counterweight arrangement <NUM>.

An example of the counterweight arrangement <NUM>, shown in <FIG>, may be applied in the crane <NUM> of <FIG> in ways presented in the above description. According to the different examples and alternatives, at least some of the parts, apparatuses, structures, and components of the counterweight arrangement <NUM> of <FIG> may also be placed elsewhere in the crane <NUM>, for example in the frame structure <NUM>. For example, control valves <NUM> controlling the function of the outriggers <NUM> may be placed in the frame structure <NUM> or in the outrigger <NUM>. One part of the control system <NUM> may be placed in the counterweight arrangement <NUM> and another part elsewhere in the crane <NUM>. In some cases, the control device <NUM> may be remote from the crane <NUM> during the control of its functions.

Claim 1:
Mobile loader crane (<NUM>), comprising:
a column structure (<NUM>);
a boom (<NUM>) which is telescopic, connected to the column structure by articulation, and configured to move up and down;
a turning device (<NUM>), on which the column structure (<NUM>) is mounted and which is configured to swivel the column structure (<NUM>) and the boom (<NUM>) together in two lateral directions, around a substantially vertical direction (X) and said turning device (<NUM>) is further mounted on a frame structure (<NUM>),
at least two movable outriggers (<NUM>) which can be placed against the ground or a floor and which are configured to support and stabilize the crane (<NUM>);
a control system (<NUM>) which is configured to control the functions of the crane (<NUM>) and which comprises at least one control device (<NUM>), by which an operator may manually control the functions of the crane (<NUM>);
at least one power source apparatus (<NUM>) for generating the power needed by the functions of the crane (<NUM>); the crane further comprises:
a crawler frame (<NUM>) for moving the crane and comprising a frame structure (<NUM>) and motorized first and second crawler tracks (<NUM>, <NUM>) placed on opposite sides of the frame structure; and in which crane the turning device is further mounted on the frame structure of the crawler frame, and the above-mentioned outriggers are connected to the frame structure of the crawler frame; and
a counterweight arrangement (<NUM>) connected to the column structure (<NUM>), wherein the counterweight arrangement (<NUM>) is configured to swivel together with the column structure (<NUM>) and the boom (<NUM>) and is further suitable for acting as a counterweight for the boom (<NUM>) and/or for loads to be connected to or suspended from the boom (<NUM>)
characterized in that:
at least one of said power source apparatuses (<NUM>) is placed in the counterweight arrangement (<NUM>); and said power source apparatus (<NUM>) comprises either an electric motor or a combustion engine, or both, for generating the power needed for the functions of the crane (<NUM>).