Device for detecting a position of a hoisting frame and use thereof to control a hoisting frame suspended from a crane

Abstract

A device for detecting a position of a hoisting frame includes one or more image sensors connected movably to the hoisting frame and protruding outside a periphery thereof in a position of use. The image sensors can be movable between the position of use and a protected position lying within the periphery of the hoisting frame. The device can be provided with means for biasing the image sensor(s) from the protected position to the position of use. A method for controlling a hoisting frame suspended from a crane includes moving the hoisting frame to a first position under the control of an automatic control system, holding the hoisting frame stationary in the first position, making one or more image recordings of the area around the hoisting frame in the first position and moving the hoisting frame to a second position on the basis of the image recording(s), wherein the image recording(s) is/are made by one or more image sensors connected to the hoisting frame.

Claims

1. A device for detecting a position of a hoisting frame, comprising: at least one sensor which is connected movably to the hoisting frame and protrudes outside a periphery thereof in a position of use and which is movable between the position of use and a protected position lying within the periphery of the hoisting frame, wherein the hoisting frame is elongate and has two mutually opposite short sides, wherein each of the short sides has two mutually opposite ends with couplings arranged on or close to these ends, wherein each short side of the hoisting frame is formed by an end beam, and the hoisting frame further comprises at least one longitudinal beam, and wherein the at least one sensor is an image sensor and at least one image sensor is arranged on each of the short sides at a position lying between the ends thereof, wherein the at least one image sensor is arranged on the end beam substantially in line with the at least one longitudinal beam, and further comprising biasing means for biasing the at least one image sensor from the protected position to the position of use.

2. The device of claim 1, wherein the biasing means are mechanical biasing means.

3. The device of claim 1, wherein the hoisting frame has an upper side with means for suspension thereof from hoisting elements and an underside lying opposite the upper side, and the at least one image sensor has a field of vision oriented toward the underside of the hoisting frame.

4. The device of claim 3, wherein the field of vision of the at least one image sensor comprises a lower edge of a load attached to the hoisting frame.

5. The device of claim 1, wherein the at least one image sensor comprises a camera or a scanner.

6. A device for detecting a position of a hoisting frame, comprising: at least one sensor which is connected movably to the hoisting frame and protrudes outside a periphery thereof in a position of use and which is movable between the position of use and a protected position lying within the periphery of the hoisting frame, wherein the hoisting frame is elongate and has two mutually opposite short sides, wherein each of the short sides has two mutually opposite ends with couplings arranged on or close to these ends, wherein each short side of the hoisting frame is formed by an end beam, and the hoisting frame further comprises at least one longitudinal beam, and wherein the at least one sensor is an image sensor and at least one image sensor is arranged on each of the short sides at a position lying between the ends thereof, wherein the at least one image sensor is arranged on the end beam substantially in line with the at least one longitudinal beam, and wherein the at least one image sensor is received in a body which is shaped such that under the influence of an external load it moves to the protected position.

7. The device of claim 6, wherein the body has a base part which faces toward the hoisting frame and is relatively wide and an outer end which faces away from the hoisting frame and is relatively narrow, and the at least one image sensor is arranged in or close to the narrow outer end.

8. The device of claim 6, wherein the body is mounted slidably in the hoisting frame.

9. The device of claim 6, wherein the body is mounted pivotally in the hoisting frame.

10. The device of claim 6, wherein the body is manufactured from a material able to withstand impact loads.

11. The device of claim 6, wherein the at least one image sensor comprises a camera or a scanner.

12. A device for detecting a position of a hoisting frame, comprising: at least one sensor which is connected movably to the hoisting frame and protrudes outside a periphery thereof in a position of use and which is movable between the position of use and a protected position lying within the periphery of the hoisting frame, wherein the hoisting frame is elongate and has two mutually opposite short sides, wherein each of the short sides has two mutually opposite ends with couplings arranged on or close to these ends, wherein the at least one sensor is an image sensor and at least one image sensor is arranged on each of the short sides at a position lying between the ends thereof, and wherein the hoisting frame has an upper side with means for suspension thereof from hoisting elements and an underside lying opposite the upper side, and the at least one image sensor has a field of vision oriented toward the underside of the hoisting frame; and further comprising biasing means for biasing the at least one image sensor from the protected position to the position of use.

13. The device of claim 12, further comprising means for connecting the at least one image sensor to a control system for a crane from which the hoisting frame is suspended.

14. The device of claim 12, wherein the field of vision of the at least one image sensor comprises a lower edge of a load attached to the hoisting frame.

15. The device of claim 12, wherein the at least one image sensor comprises a camera or a scanner.

16. A device for detecting a position of a hoisting frame, comprising: at least one sensor which is connected movably to the hoisting frame and protrudes outside a periphery thereof in a position of use and which is movable between the position of use and a protected position lying within the periphery of the hoisting frame, wherein the hoisting frame is elongate and has two mutually opposite short sides, wherein each of the short sides has two mutually opposite ends with couplings arranged on or close to these ends, and wherein the at least one sensor is an image sensor and at least one image sensor is arranged on each of the short sides at a position lying between the ends thereof, and further comprising means for connecting the at least one image sensor to a control system for a crane from which the hoisting frame is suspended; and further comprising biasing means for biasing the at least one image sensor from the protected position to the position of use.

17. The device of claim 16, further comprising means for biasing the at least one image sensor from the protected position to the position of use.

18. The device of claim 16, wherein the at least one image sensor is received in a body which is shaped such that under the influence of an external load it moves to the protected position.

19. The device of claim 16, wherein the at least one image sensor comprises a camera or a scanner.

20. The device of claim 16, wherein each short side of the hoisting frame is formed by an end beam, and the hoisting frame further comprises at least one longitudinal beam, wherein the at least one image sensor is arranged on the end beam substantially in line with the at least one longitudinal beam.

Description

(1) The invention will now be elucidated on the basis of two examples, wherein reference is made to the accompanying drawing in which corresponding components are designated with the same reference numerals, and in which:

(2) FIG. 1 is a perspective top view of a part of a hoisting frame and container attached thereto, wherein the hoisting frame is provided with a detecting device according to a first embodiment of the invention;

(3) FIG. 2 is a top view of a part of the hoisting frame and the container of FIG. 1 in which the field of vision of the detecting device is represented schematically;

(4) FIG. 3 is a side view of a part of the hoisting frame and the container of FIG. 1 in which the field of vision of the detecting device is represented schematically;

(5) FIG. 4 is a view corresponding to FIG. 3 in which the detecting device is shown in partial longitudinal section;

(6) FIG. 5 is a front view of a part of the hoisting frame and the container of FIG. 1 in which the field of vision of the detecting device is represented schematically;

(7) FIG. 6 is a detail view on enlarged scale of the detecting device in the hoisting frame of FIG. 5;

(8) FIGS. 7, 8 and 9 are side views which show how the hoisting frame and the container are lowered into a cell, wherein the detecting device is urged to its protected position in the hoisting frame by contact with the surrounding area;

(9) FIG. 10 is a schematic top view of a hoisting frame with a detecting device on either side; and

(10) FIG. 11 is a schematic cross-section of an alternative embodiment of the detecting device.

(11) A hoisting frame 1 in the form of a spreader (FIG. 1) comprises two longitudinal beams 2 and two end beams 3 running in transverse direction. Longitudinal beams 2 are mounted slidably in a central frame part 23 (FIG. 10) which is provided with cable pulleys 24 around which are trained the hoisting cables with which hoisting frame 1 is suspended from a crane. Hoisting frame 1 bears a load, in the shown example a unit load or container 4. Container 4 is attached to hoisting frame 1 by means of couplings 5 at the outer ends of end beams 3 in the form of so-called twist-locks. These twist-locks are mounted in corner castings 6 of container 4.

(12) In order to be able to monitor the movements of hoisting frame 1 and load 4 attached thereto during hoisting or lowering the hoisting frame 1 is provided with a device 7 for detecting the position of hoisting frame 1. This detecting device 7 is connected to a control system of the crane. This connection, which is not further shown here, can be effected wirelessly as well as via wiring.

(13) Detecting device 7 comprises one or more image sensors 8 which are connected movably to end beams 3 of hoisting frame 1 at a position substantially halfway between twist-locks 5 and which during use protrude outside the periphery of hoisting frame 1. Image sensor 8 is formed in the shown embodiment by a camera, although another type of image sensor, such as for instance a scanner, can also be envisaged. Camera 8 is oriented downward (FIG. 3, 5) so that a field of vision 9 of the camera includes a lower edge 10 of the container attached to hoisting frame 1. Camera 8 and thus properly detect the position of lower edge 10 relative to a cell in a vessel. Because of the central position this single camera 8 covers substantially the whole width of the container.

(14) In order to protect camera 8 from damage through contact with objects in the vicinity of hoisting frame 1, camera 8 is movable from the shown protruding position of use to a protected position in which it lies within the periphery of hoisting frame 1. In the shown embodiment camera 8 is received for this purpose in a body 11 which is mounted slidably in hoisting frame 1. Means 12 are present which urge or “bias” body 11 with camera 8 therein back to the position of use outside the periphery of hoisting frame 1. These biasing means 12 can be of mechanical nature and can take a spring-mounted form.

(15) Body 11 is shaped here such that, under the influence of an external load, it moves to the protected position within the periphery of hoisting frame 1. In the shown embodiment this is realized in that body 11 has a tapering form, in particular a truncated conical form. With a suitable choice of the apex angle α of this cone loads in vertical direction can be converted to a horizontal sliding movement of body 11 in hoisting frame 1. In the shown embodiment the apex angle α amounts to 90°, although other values can also be envisaged. In order to guarantee that body 11 is always urged inward upon contact with an obstacle, it is preferred to select the largest possible apex angle α so that the inward directed component of the load is as great as possible. Should the movement of body 11 nevertheless be blocked, this not only entails the risk of damage to camera 8 but it could in the worst case even result in hoisting frame 1 becoming jammed A large apex angle α moreover results in a robust construction of body 11, whereby it can properly withstand the loads which occur.

(16) In the shown embodiment body 11 has a cylindrical base 13 which is slidable in a bearing bush 14 which is in turn received in an opening 15 in a side wall 21 of end beam 3 (FIG. 4). Because sufficient space is available in end beam 3 at the position of the connection to longitudinal beam 2, bearing bush 14 and body 11 with camera 8 therein can be given a relatively large and robust form. Protruding on the inner side from base 13 is a pin 16 which is received slidably in a central sleeve 17 and which has a thickened end 18. This dual guiding prevents the body 11 hanging askew and jamming A compression spring 19 is arranged round pin 16 between base 13 and sleeve 17. This compression spring 19 forms an embodiment of biasing means 12.

(17) Body 11 is manufactured wholly or partially from a material which can properly withstand impact loads and which is sufficiently wear-resistant. The material from which body 11 is manufactured must moreover generate relatively little friction. In the shown embodiment body 11 is made from a plastic, although an embodiment in rubber could also be envisaged. Different types of metal can in addition be considered suitable, although it is important to select these such that body 11 cannot cause any damage to the surrounding area.

(18) Camera 8 is arranged close to the narrow outer end 20 of body 11, but is recessed to some extent in order to be optimally protected from contact with obstacles. In the position of use camera 8 is situated here so far outside side wall 21 of end beam 3 that even a lower edge 22 of end beam 3 lies in its field of vision 9. Camera 8 can thus also be used in the control of movements of hoisting frame 1 when it is manoeuvred toward a load 4. In addition, the field of vision 9 will of course cover a significant part of the area surrounding hoisting frame 1 so that a good indication is obtained of the position of hoisting frame 1.

(19) For optimal control of the movements of hoisting frame 1 it is important that the most complete possible indication of its position is formed. In the shown embodiment each end beam 3 is provided for this purpose with a camera 8 protruding outside its side wall 21 (FIG. 10). Cameras could if desired also be arranged in or on side walls 25 of central body 23. Here too there is sufficient space for camera bodies in large and robust form.

(20) Although in the shown embodiment body 11 with camera 8 is mounted slidably in hoisting frame 1, other types of movement can also be envisaged for moving camera 8 to a protected position within the periphery of hoisting frame 1. According to another embodiment of the invention, body 11 is mounted for pivoting to all sides in a relatively oversize opening 15 (FIG. 11). Body 11 is once again provided with a pin 16, which is mounted here in a ball hinge 26. Biasing means 12 here comprise a number of radially oriented springs 19 which centre the body 11 in opening 15 and which after each movement urge it back again to the central position in which camera 8 protrudes outside the periphery of hoisting frame 1.

(21) As stated, the images from camera 8 are transmitted to a control system. The control system is largely automated and is configured to manoeuvre the hoisting frame autonomously to a position in the vicinity of a cell 27 in a vessel. Here the movement of hoisting frame 1 is stopped, after which an operator takes over control and, on the basis of the images from camera 8, lowers hoisting frame 1, with a possible container 4 attached thereto, into cell 27. It is advantageous here for different points on hoisting frame 1 and container 4 to be shown simultaneously by cameras 8 at different locations so that all obstacles in the surrounding area, for instance all edges of a cell 27, can be seen. Once container 4 and/or hoisting frame 1 are situated in cell 27, the remaining movement is once again carried out autonomously by the control system. A single operator can in this way monitor and, where necessary, control different cranes, this resulting in considerable savings compared to conventional cranes which are each controlled by an individual crane driver.

(22) It is otherwise also possible to envisage that future control systems will be able to process the images digitally and also perform this critical step in the movement of hoisting frame 1 autonomously on the basis thereof.

(23) When hoisting frame 1 is lowered into cell 27 (FIG. 7), body 11 with camera 8 therein will at some point come into contact with the surrounding area, either a wall of cell 27 or an upper edge 28 of an adjacent container 44 (FIG. 8). Because body 11 moves with its sloping side along upper edge 28, it is pushed inward into bearing bush 14 counter to the pressure of compression spring 19 (FIG. 9). Camera 8 is thus protected from the surrounding area. When hoisting frame 1 is moved upward again out of cell 27, body 11 is once again urged outward by compression spring 19 to its position of use protruding outside the periphery of hoisting frame 1.

(24) The invention thus makes it possible to precisely control a hoisting frame 1 on the basis of images made at the location of the hoisting frame itself without the risk of damage to the detecting device or blocking of the movement of the hoisting frame.

(25) Although the invention has been elucidated above on the basis of a number of examples, it will be apparent that these can be varied in many ways. The scope of the invention is therefore defined solely by the following claims.