The invention relates to a multiple trolley container crane having at least two trolley tracks disposed one above the other, in accordance with the preamble of the first claim.
The invention is suitable for cranes in which several trolleys are disposed on different trolley tracks, whereby there is the possibility that the trolleys switch from one trolley track to another. The system is particularly suitable when the possibility is supposed to exist that several trolleys switch their tracks at the same time, move independently of one another, and no specific location is required for changing the trolleys from one trolley track to the other. The invention can be used in very particularly advantageous manner when several trolleys pick up containers at the same time and, traveling one behind the other, bring the containers to the planned location. This can take place both from a container ship to a vehicle that is standing ready, or to a collection area, and vice versa.
Since container ships are becoming larger and larger, and because of the docking times in the harbors, there is a demand for loading and unloading as many containers as possible within the shortest possible amount of time, and at a high speed. It is true that several container bridges can be placed next to one another against the container ships along the longitudinal side of the ship, but these are predominantly single-trolley container bridges, i.e. one trolley picks up the container from the ship and brings it to the pier, or vice versa. In the case of large container ships, this means long docking times.
A container crane having two trolleys is known from DE 298 24 751.8, which trolleys can work independently of one another. The proposed variant is limited to two trolleys, however, so that several container cranes must be used for fast unloading.
A load loading crane is known from DE 43 07 254 A 1, in which three trolleys are disposed on a container bridge, whereby two lifting units that can be moved in their longitudinal direction, having a lifting mechanism and a transfer unit are disposed for the load exchange. In the case of this system, the advantage of the transport path division is canceled out by the multiple release and gripping of the container.
A transport system is known from EP 0 167 235 A 1, with which several containers, one after the other, can be loaded onto and unloaded from a ship, but the trolleys always move on the same tracks, so that while several trolleys can load and unload containers at the same time, the system has the disadvantage that first, all of the loading and unloading procedures must have been completed, before the next unloading and unloading procedures can be carried out.
In order to move several trolleys on different tracks at the same time, without these hindering one another, a portal crane having circulating trolleys is known from WO 00/48 937, in which several trolleys are disposed next to and on top of one another, and move on different tracks in two different level heights. A disadvantage of this portal crane having circulating trolleys, however, is that the upper trolleys with the hoists only perform the lifting and lowering movements of the containers, and the trolleys on the lower tracks only take over the transport of the containers to and from. It is true that several containers can be lifted and transported at the same time, but different trolleys are required for the transport and for lifting, which trolleys handle the lifting and transport procedure with a division of labor. As a result, a multiple transfer of containers on the container crane is required, and this results in an increased use of materials and error sources. Furthermore, in the case of two or more lifting and lowering trolleys, there are significant crossover problems between the lifting and transport procedure. It is also disadvantageous that every container must be brought into the uppermost trolley lifting position in order to be transferred and transported further. It is furthermore disadvantageous that a switch in track is always possible only at the end of the tracks, so that significant distances must be traveled by the trolleys.
It is therefore the task of the invention to develop a multiple trolley container crane on which several trolleys can move at the same time, at different height levels, whereby the transport of several containers is supposed to be possible with a simple method of construction and procedure.
This task is accomplished by means of a multiple trolley container crane that has the characteristics of the first claim.
Dependent claims reproduce advantageous embodiments of the invention.
The solution according to the invention provides for a multiple trolley container crane having at least two trolley tracks disposed one on top of the other, on which trolleys having running wheels, drive devices, and lifting devices move, which crane is characterized in that the trolleys on the trolley tracks have running wheels that can be laterally retracted and extended. These running wheels are retracted during the switch of the trolley from one trolley track to the next higher trolley track, and are extended again on the next higher trolley track. Fundamentally, at least two trolley tracks disposed on top of one another must be disposed on each side of the trolley. It is also possible to dispose more than two trolley tracks one on top of the other. Every trolley has an integrated lifting system with which it can support itself on or next to the trolley tracks and thereby get from one trolley track to the other trolley track. In this connection, it is possible that the trolley moves from an upper trolley track to the one located below it. The lifting system can not only engage on a trolley track, i.e. in front of or behind the running wheels, it can also engage on a suitable location next to a trolley track. After the lifting system is supported on or next to the trolley track, the lifting system transports the running trolley, with the wheel pairs retracted, up or down, and afterwards, the wheel pairs are extended again, after the lifting movement, and the trolley is lowered to the running surface. Afterwards, the lifting system can be retracted again.
When only two trolley tracks are present, the track width of the running wheels can be adjusted by means of fixed stops.
Telescoping cylinders that are disposed next to or under each running wheel are suitable as an integrated lifting system.
However, gear wheels that are used to move racks are also suitable; they bring about an upward or downward slide of the trolley, in each instance.
Every trolley is provided with a drive device; furthermore, there is a lifting device on every trolley, which devices can be spreaders, for example, having gripping elements, for example twistlocks.
It is advantageous to dispose several trolleys behind one another on the upper and/or the lower trolley track. In this way, several trolleys can move on the upper trolley tracks, without a load, above the trolleys on the lower trolley tracks, and several trolleys that are carrying their loads can move on the lower trolley tracks, next to one another and at the same time.
For stability, trolley track connections can be disposed between the two sides of the trolley tracks, between the upper trolley tracks and the lower trolley tracks.
Furthermore, it is advantageous to structure the trolleys so that they have extendable power supplies. In this way, it is possible to perform the lifting and the lowering procedure of the trolley from one track to the other, without any power supply hindering this procedure. The power is then made available to the trolley in question by way of a storage unit, for example a battery. The lifting and lowering procedure of the trolleys can be controlled by way of radio control. To control the procedures of the trolleys during container loading and unloading, one or more crane operator's cabin(s) can be disposed on the container crane, in fixed or movable manner. It is advantageous to undertake the operation of the trolleys automatically, whereby monitoring and regulation devices for automatic pick-up and set-down of the containers and for preventing collisions should advantageously be disposed on the container crane or on the trolleys.
The multiple trolley container crane has the advantage of a simple method of construction, whereby several trolleys are put into use at the same time, whereby a simultaneous switch of several trolleys on the trolley tracks is possible, and the function of the trolleys can take place independently of one another, to the greatest possible extent, whereby no specific location is necessary for switching the trolleys from one trolley track to the other.
In the following, the invention will be explained in greater detail using five figures and an exemplary embodiment. The figures show:
For stabilization, track connections 15 are disposed between the trolley tracks 6, 7.
List of reference symbols used:
Number | Date | Country | Kind |
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10313769.6 | Mar 2003 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE04/00583 | 3/22/2004 | WO | 10/19/2005 |