Container loading and unloading system

Background

Transport of goods is increasingly carried out using standardised receptacles such as containers and tanks to achieve optimum space utilisation in storage as well as transport. This also allows the use of standardised hoists for simple mechanisation of load handling.

Fig 1 - Schematic of the individual stations of the patented method

Means of long-distance transport are high-value investments, and so should have the shortest possible downtimes including stoppages for loading an unloading. Load and unloading of trains, which may be a few hundred metres long, may be extremely time consuming, and marshalling of such trains in yards is labour-intensive. As an alternative to train-make-up, the loads, involving uniform rolling material, can be ordered correctly respective loading elsewhere, provided the necessary logistics is available.

Among the search for previous relevant patents the inventors refer to two in particular:

- WO 99/10258 world patent of 1999

- EP 0 599 841 B1 European patent of 1995

The first refers to a storage facility for goods of random dimensions on cargo carriers that are moved vertically and horizontally on various devices in the rack, and controlled by a data processing unit. According to the inventors, the multiplicity of vertically aligned transport lanes and vertical conveyor devices, as well as horizontal movement, results in complex constructions prone to malfunction because of their multiplicity.

The second patent is for a method of device for trans-shipping containers employing rolling pallets. As in this invention (see below) the loads, as well as the rolling pallets, are prepositioned in the desired sequence next to the rail track for quicker train loading. Control is also by a data processing system. Belt conveyors are proposed as an alternative to rolling pallets. Again the inventors say that the complicated construction of this system would be prone to malfunction.

Description

Figure 1 shows the development as a preferred embodiment with two means of long-distance transportation, a highway truck (1) and a train (2), situated in parallel. Between a 3-level, high-rise storage rack (3) and the train track is a transfer zone (4) to receive the cargo. As shown there is a hoist on a gantry crane disposed above the train. This has a transverse rail (6) for movement of the crane trolley (7) and the spreader or gripper (8) from the axis of the highway truck, over the train, and to the transfer zone.

Between the storage rack and the transfer zone is a further hoist (11), which moves along a rail (12). This equipment includes two telescopic arms (13) on which a spreader (not shown) can travel from the transfer zone into the rack. The telescopic arm can also travel vertically on the supports (17) so that the spreader can move to the bays of the intermediate storage rack (14, 15 and 16). The vertical supports of this hoisting equipment stand behind one another and are interconnected at their upper end by a cross-member. The telescopic arms are also secured by a cross-member that can move vertically along the supports. The arms can be displaceable if required.

The cargo (a standard container or similar), is shown in various positions.

Method

The cargoes on the highway truck or trains (multiple tracks may be covered) will be identified by a reader on the spreader, or visually, and the date entered into a processing system. The identification will establish the destination and receiver. The cargo is lifted from a long-distance transport carrier (1) and passed to a transfer zone (4) or another means of transport, lowered and set down. The positioning takes into consideration the next train intended for the container's destination. An operator must monitor this transfer. The spreaders on the hoists include sensors to facilitate the insertion of the holding pins in the load receptacles. Rotation of the spreader may be required to lift from non-parallel transport such as a highway truck. This may also be required for unevenly loaded containers etc.

If the cargo is destined for intermediate storage the second hoist is operated by the data processing system to move in front of the container to lower the spreader and lift the container. The spreader is moved until the container is positioned with its centre-of-gravity above the hoist rail (12). Subsequently the container is transported horizontally to the predetermined storage location, and lifted to the correct bay. Markings on the vertical supports co-operate with sensors on the telescopic arms. There are respective markings on the bays for accurate positioning of the second hoist in front the individual bays in conjunction with sensors on the vertical supports and telescopic arms. The container is then moved into the correct bay and lowered.

When loading a train the correct containers can be placed in the transfer zone in the required order prior to arrival of the empty train, or the train loaded directly. A selected container is withdrawn from the storage racks by the second hoist, again controlled by the data system, and lowered on the transfer zone in accordance with the logistics demands. Once the train has arrived the containers can be transported by the first hoist from the transfer zone (or highway truck) across to the train cars. If there are parallel tracks loads can be moved from one train to another. The number of first and second hoists, as well as the length of the transfer zone and the intermediate storage facility, depend on the intended loading times and the length of the train to be loaded.

More precise control and/or regulation of the movement of hoists can be carried out using more position transducers so that the position can be determined relative to key locations such as the intermediate storage facility, transfer zone, a rail car, and/or detect the distance travelled.

Advantages

The patented development intends to improve on previous system designs in providing a means of unloading, storage and loading of transport systems with no other equipment than horizontally and vertically moving hoisting equipment, in a small space. Thus rolling pallets (vertical conveyors, horizontal conveyors etc) are eliminated. All movements can be controlled by a data processing system according to the dimensions of the equipment and the logistics requirements. Devices and media providing the input data include bar codes, chips, video cameras on operator input.

In using standardised cargo, the storage spaces can be made precisely to suit the cargo, thus considerably reducing the demand for space and allowing the use of standardised hoists.

The system separates the unloading of the means of transport and transport to intermediate storage so that the number of hoists can be suited to the varying time constraints or their individual actions. Holding of containerised cargo in the intermediate storage racks (single or multiple) avoids the stacking of containers so that each container can be withdrawn individually without rearrangement whilst providing precise storage positioning and reliable identification for withdrawal.

As standardised gripper hoists are used there is no need to equip the cargo container etc with additional strengthening in certain regions.

The cargo can be manipulated by swinging upon the hoist about the vertical axis, so there is no need for precise alignment of the train etc in parallel relationship, being loaded directly. This operation is important for a small demand on space in the intermediate storage facility. Similarly the cargo can be swung about a horizontal axis for parallel alignment to the platform of the means of transport or precise adjustment to the storage facility.

Cargo handling involves particularly short transport paths. The unloading process can also be executed when a loaded or partially loaded train is involved as the cargo only has to be lifted higher to avoid it.

Assembly of the correct order of cargoes in the transfer zone prior to arrival of the train can significantly shorten the period for loading the train. All that is needed is to lift each cargo across a short horizontal displacement.

About the patent

This article is an edited version of US Patent 7,287,953 published October 30 2007 from an application filed September 9 2003. The inventors are Dietmar Schratt and Helmut Klaus Schimany of Vienna, Austria, and the invention is assigned to Rail Cargo Austria AG.

Disclaimer

This article is an edited version of the patent and may omit legally or technically important text. To see the full patent go to www.hoistmagazine.com/patents.

Market status

The patent assignee, Rail Cargo Austria AG (RCA), is an independent company offering full logistics services including tailor-made transport systems for any kind of cargo or industry. It operates mainly in central Europe. The Company was formerly part of ÖBB-Güterverkeht, the Austrian national rail system, but has been independent since January 1 2005.