GB2055749A

GB2055749A - An operating system for a lifting device

Info

Publication number: GB2055749A
Application number: GB8021597A
Authority: GB
Original assignee: LENSINK
Current assignee: LENSINK
Priority date: 1979-07-02
Filing date: 1980-07-02
Publication date: 1981-03-11
Also published as: SE7905757L; DE3024605A1; NL8003838A

Abstract

A container lifting device for mounting on a working machine comprises a frame 2 and a support beam 3 connected thereto and a lifting beam 4 having engagement means 8 for engaging a container, an operating system including hydraulic means 5 for operating the lifting device, and pre-set positioning means for adjusting the position of the support beam relative to the bottom of the container, and sensor means for controlling the engagement of and positioning of the lifting beam and support beam relative to the container. <IMAGE>

Description

SPECIFICATION An operating system for a lifting device The present invention relates to a method for lifting and depositing a container by way of a lifting device, which is controlled by a particular operating system.

The lifting device is preferably of the kind that is intended for mounting on a working machine, such as on the stand of a lift truck. The lifting device comprises a frame and a support beam connected thereto and a transverse lifting beam (top spreader) having means such as twist locks for engagement with the container. The operating system includes hydraulic means for operating the lifting device including the lifting beam but includes other means as well which are to be described below.

Due to the more and more increasing container traffic and thus the increasing handling of containers there is a need for a lifting device and an operating system therefor which implies a simplified handling of containers and which system is reliable in use.

According to the invention the deficiencies of lifting devices and operating systems previously known can be eliminated and simultaneously the advantages mentioned above can be achieved.

Thus, the invention relates to a method for lifting and depositing a container by way of a lifting device, preferably a lifting device for mounting on a working machine, such as on the stand of a lift truck, the lifting device comprising a frame and a support beam connected thereto and a lifting beam having means such as twist locks for engagement with the container, and an operating system including hydraulic means for operating the lifting device including the lifting beam.The method is characterized by moving the lifting device towards the container in a somewhat forwardly inclined position and bringing the engagement means into corner fittings of the container, a pre-set positioning means being then selected, which when actuated automatically adjusts the height of the lifting device in relation to the container to be lifted by way of sensor means, the hydraulic means being then actuated to lower the support beam to the position selected, and to bring the engagement means to a locked position in the corner fittings to enable the lifting of the container.

According to a preferred embodiment the lifting beam is telescopic. According to an important aspect of the invention the support beam is adjustable in height.

Further features and advantages of the invention will be apparent from examples of embodiments described below, reference being made to the accompanying drawings, on which Figure 1 shows a lifting device, Figure 2 shows another embodiment of a lifting device and Figure 3 shows a diagram for an operating system.

With reference now to Figure 1 and 2there is shown a lifting device 1 having means for connection to the stand of a lift truck. The lifting device 1 comprises a frame 2, a lower beam or a support beam 3, which is provided with a vertical beam 2 for a movement into and out of the frame 2 which is thus hollow, and a transverse lifting beam or a top spreader 4. According to the embodiments shown on Figure 1 and 2 the lifting beam 4 consists of two telescopic beams 7 which thus are movable into and out of the housing 6. The beams 7 thus function as side spreaders. The end parts of the beams 7 are provided with twist locks 8 for engagement with corner fittings of a container. The construction of the twist locks is conventional and is not shown in detail.

The support beam 3 is provided for height adjustment, confer arrows 9 in Figure 2, by way of hydraulic pistons 5, of which only one being shown on the drawings.

With further reference to Figure 3 there are shown two magnetic valves 12 and 13 for the twist locks 8 and for the height adjustment of the support beam 3 respectively. According to a preferred embodiment there is provided a slit in the frame 2 and shoulderstips are provided on the frame 2 and on the vertical beam 2 together with sensor means to define and detect the various the various levels. On Figure 3 there is also shown a number of sensors including proximity sensors, such as a sensor 14 for safety locking of the twist locks 8 and sensors 15 and 16 to detect if the locks are in the locked or in the unlocked position.A sensor 17 is provided to detect if there is alignment of the support beam 3 against the container side and sensors 18 - 21 are provided for various container sizes, such as 8', 8' 6", 9' and 9 62 (height).

An electronic proximity sensor 25 is provided to detect if the mast of the truck is tilted forward sufficiently. On the upper beam 4 there are warning lights 22 - 24 indicating if the beam 4 is connected to the container, i.e. if the twist locks 8 are sealed or not sealed in the corner fittings of the container. In the cabin there is an electric control box 26 with push buttons 27 - 31 marked 8', 8' 6", 9', 9' 6" and "release".

According to a preferred embodiment the upper beam 4 is telescopic from 20' to 40'. In other words, the end positions correspond to 20 (fully retracted) and 40' (fully extracted) and an intermediate position may correspond to 30 The beam 4 has two hydraulically operated twist locks 8. The operation of these locks is controlled by an electro-valve mounted on the upper beam 4. By way of the electronic proximity sensors 14, 15,16 and 25 mentioned above, the truck driver can decide if the twist locks 8 have properly entered the corner fittings, if the locks 8 are in the locked or in the unlocked position and if the mast of the truck is tilted forward sufficiently. The signals of these sensors are used to prevent the driver from making errors.

As previously mentioned the lower beam 3 is hydraulically adjustable in height. The movement of this beam can be stopped in exactly determined positions thanks to the use of the same type of sensors as described above. Confer the slit-shoulder arrangement mentioned above. As a result thereof the lower beam 3 will touch the reinforced bottom section of the container when its height is 8', 8'S", 9' or9' 6".

The operation of the lifting device according to the invention will be described below in detail.

The driver moves the truck with the lifting device mounted thereon towards the container with the mast of the truck tilted forward 1 - 3 degrees, preferably 1 - 1.5 degrees. The twist locks are then lowered into the corner fittings of the container, until the corresponding warning lights lit up. In this position it is easy for the driver to compare the height of the container with the actual position of the lower beam 3. Then the driver is forced to make a decision about the container height and after that the driver pushes the corresponding button of the control box in the cabin and pulls the hydraulic lever.

If the mast is tilted forward as required, the lower beam 3 will now descend and then stop at the position previously selected. Automatically and without interruption the twist locks will be turned as the lower beam 3 reaches its proper position. The container can now be lifted in the normal way. Of course, the tilted mast must be moved backwards before the container is lifted.

When depositing the container the driver must tilt the mast forward, push the release button and push the hydraulic control lever in the reverse direction.

The lower beam will first go up to the 8' position (assuming for example a 9' container is being handled) and automatically the twist locks 8 will unlock as soon as the lower beam 3 has stopped.

Thus, there is an automatic switch over to the opening of the locks. The above sequence makes it impossible for the driver to damage the upper beam by driving without container and with the lower beam in a lowered position.

Modifications of the lifting device and the operating system are obvious to one skilled in the art without departing from the scope of the invention. It should thus be mentioned that fixed upper beams can be used instead of telescopic beams. Further, extra hydraulic lifting means may be provided.

Claims

1. A container lifting device for mounting on a working machine comprising a frame and a support beam connected thereto and a lifting beam having engagement means for engaging a container, an operating system including hydraulic means for operating the lifting device, and pre-set positioning means for adjusting the position of the support beam relative to the bottom of the container, and sensor means for controlling the engagement of and positioning of the lifting beam and support beam relative to the container.

2. A container lifting device as claimed in claim 1, wherein the pre-set positioning means are manually controlled switches which correspond to the height of the container.

3. A container lifting device as claimed in claim 1, wherein the sensor means are proximity switches, which can detect whether the engagement means have properly engaged with the container, whether the engagement means are locked or unlocked, whether the support beam is aligned against the container side, and whether the frame is tilted towards or away from the container.

4. A container lifting device as claimed in claim 1, wherein the hydraulic means are hydraulic pistons.

5. A container lifting device substantially as herein described with reference to the accompanying drawings.

6. A method of lifting and depositing a container by way of a lifting device, preferably a lifting device for mounting on a working machine, such as on the stand of a lift truck, the lifting device comprising a frame and a support beam connected thereto and a lifting beam having means such as twist locks for engagement with the container, and an operating system including hydraulic means for operating the lifting device, characterized by moving the lifting device towards the container in a somewhat forwardly inclined position and bringing the engagement means into corner fittings of the container, a pre-set positioning means being then selected, which when actuated automatically adjusts the height of the lifting device in relation to the container to be lifted by way of sensor means, the hydraulic means being then actuated to lower the support beam to the position selected, and to bring the engagement means to a locked position in the corner fittings to enable the lifting of the container.

7. A method of lifting and depositing a container substantially as herein described with reference to the accompanying drawings.