The invention relates to a container spreader for coupling a container with a hoisting installation, comprising a lifting frame provided with coupling means for coupling to the hoisting installation, and a number of guide plates connected to the lifting frame for guiding the container spreader during coupling of the container spreader with a container, which guide plates are each connected to a separate hydraulic swivel motor which can move the guide plate connected thereto between an active position, in which the guide plates guide the container spreader to the container, and an inactive position, in which the guide plates are folded away so that they cannot come into contact with the container.
Such a container spreader is known, inter alia, from ST20-STS Separating Twin-Twenty Expandable Spreader (EARLS INDUSTRIES) 2013; (see http://earlsindustries.com/portfolio/separating-twin-twentycontainer-spreader/gallery/shipping-container-handling/). It is customary to connect all swivel motors of such a container spreader to one hydraulic pump which is driven by an electric motor and is connected to the swivel motors via hydraulic lines. Hydraulic control valves are located between the hydraulic pump and the swivel motors for running the hydraulic swivel motors and for determining their direction of rotation. These control valves are usually mounted against the swivel motors and are connected to the hydraulic pump via hydraulic lines. With such a container spreader the hydraulic system is of such a nature that the hydraulic pump is in continuous operation in order to be able to carry out this function and eventually other functions directly. The disadvantage of this well-known container spreader is that it continuously consumes energy, continuously produces noise and is continuously subject to wear and tear. A further disadvantage of this known container spreader is that if one of the hydraulic lines gets a leak, the hydraulic fluid (usually oil) flows into the environment, which can have serious adverse consequences.
An object of the invention is to provide a container spreader of the type described in the preamble which does not have the abovementioned drawbacks of the known container spreader. More in particular, an object of the invention is to provide a container spreader which requires less energy for moving the guide plates, produces less noise and is less subject to wear than the known container spreader. To this end, the container spreader according to the invention is characterized in that each hydraulic swivel motor is connected to a separate hydraulic pump which is connected to a separate electric motor, the hydraulic swivel motor with the hydraulic pump and the electric motor forming an assembly, and wherein each assembly is connected to one of the guide plates. A relatively small swivel motor can already deliver a large torque to the output shaft with relatively little displacement of hydraulic fluid. For the drive of a hydraulic swivel motor, little pump energy (for the supply of hydraulic fluid) is required. As a result, for controlling one swivel motor, it is sufficient to use a relatively small hydraulic pump and thus also a light electric motor that requires little energy. Due to the small hydraulic circuit and short lines, it is sufficient to have an embodiment in which the electric motor is only switched on if movement of the guide plate is desired. As a result, the container spreader according to the invention is energy-efficient. In order to change the direction of movement of the guide plate, it is sufficient to change the direction of rotation of the electric motor, as a result of which the hydraulic-electric assembly according to the invention behaves the same as a known mechanical-electrical assembly.
An embodiment of the container spreader according to the invention is characterized in that each guide plate is connected via a connecting element directly to the output shaft of the hydraulic swivel motor of the assembly. By connecting the guide plate without the intervention of a transmission to the output shaft of the hydraulic swivel motor, a transmission is saved and no losses occur in the transmission.
A further embodiment of the container spreader according to the invention is characterized in that hydraulic valves are provided in each assembly between the hydraulic pump and the hydraulic swivel motor for holding the guide plate, respectively for limiting the load on the guide plate and for limiting the maximum torque of the swivel motor. Preferably, these hydraulic valves are adjustable.
The guide plates can be present at the corners of the container spreader. In that case, the guide plates are preferably bent in the transverse direction so that they have an L-shaped cross-section and come into contact with the container both at the transverse side and at the longitudinal side of the container for the purpose of aligning and guiding the container spreader with respect to the container. The guide plates can also be located at the head and long sides of the frame, with at least one guide plate on each side and two guide plates preferably on the long side of the frame. In this case, the guide plates are preferably straight in the transverse direction.
The invention will be further elucidated below on the basis of drawings. These drawings show an embodiment of the container spreader according to the present invention. In the drawings:
The assembly 7 shown in
To illustrate the operation of a swivel motor, a schematic representation of a swivel motor 13 in cross-section is shown in
In
Although the present invention is elucidated above on the basis of the given drawings, it should be noted that this invention is not limited whatsoever to the embodiments shown in the drawings. The invention also extends to all embodiments deviating from the embodiments shown in the drawings within the context defined by the claims.
Number | Date | Country | Kind |
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2019025 | Jun 2017 | NL | national |
Filing Document | Filing Date | Country | Kind |
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PCT/NL2018/050359 | 6/1/2018 | WO |
Publishing Document | Publishing Date | Country | Kind |
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WO2018/226093 | 12/13/2018 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
6863325 | Mills | Mar 2005 | B1 |
20120139274 | Fleischer | Jun 2012 | A1 |
20150360914 | Lamrouex | Dec 2015 | A1 |
20160376131 | Illana Martos | Dec 2016 | A1 |
Number | Date | Country |
---|---|---|
101927948 | Dec 2010 | CN |
102745590 | Oct 2012 | CN |
H06-255978 | Sep 1994 | JP |
2007084052 | Jul 2007 | WO |
2010021596 | Feb 2010 | WO |
Entry |
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International Search Report, dated Oct. 9, 2018, from corresponding PCT application No. PCT/NL2018/050359. |
Written Opinion, dated Oct. 9, 2018, from corresponding PCT application No. PCT/NL2018/050359. |
Number | Date | Country | |
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20200140238 A1 | May 2020 | US |