EP0633215A1 - Mechanical fall-preventing system for a heavy load gripping device - Google Patents

Abstract

The fall-prevention (drop-prevention) system allows heavy and bulky objects to be transported, by suspension, with a maximum degree of safety. It comprises a cage (40) surrounding the package to be grasped and fixed to a central hub (2) supporting a gripper sucker (1). In the lower part (6) of this cage (40) there are pivoting catches (10) which release themselves into a separated position underneath the package to be grasped as soon as the latter has been lifted up by the sucker (1). Application to the handling of containers, containing radioactive waste. <IMAGE>

Description

Field of the invention

The invention relates to the handling of packages of relatively large masses but of regular geometry. It relates in particular to a fall prevention system fitted with gripping devices of such packages, in particular devices of the suction cup type.

Prior art

In the context of handling, that is to say the storage and transport of packages or objects of determined shape, but of imposing volume, it is known to use certain gripping devices, in particular of the type operating on the using one or more suction cups.

In existing gripping devices with suction cups, the safety of the gripping members is generally only provided to compensate for a defect in the air or electricity supply of the vacuum generator group (s). In this case, the security of such a device rests solely on the presence of a vacuum reserve, generally associated with these groups and guaranteeing a setting time long enough to carry out or finish the desired handling. Of course, this security is no longer ensured in the event of deterioration of the vacuum circuits, that is to say a deterioration at the level of the suction cup (s), of the depressor group or at the level of the connections between these organs and their connections. It is also reported that this security is no longer ensured in the event of an electrical cut-off for electromagnetic gripping devices.

The object of the invention is therefore to remedy this drawback.

Summary of the invention

• une cage fixée par sa partie supérieure au dispositif de préhension, et ouverte dans sa partie inférieure de manière à pouvoir coiffer entièrement le colis à soulever ;
• au moins un loquet monté pivotant autour d'un axe situé en dessous du centre de gravité du loquet et fixé sur la partie inférieure de la cage, ledit loquet possédant à son extrémité inférieure un talon dont l'angle ≦ 90° est dirigé vers l'intérieur de la cage et qui, en prenant appui sur la surface de stockage du colis, redresse le loquet dans sa position repliée permettant ainsi la dépose du colis ;
• au moins une butée de blocage du loquet dans sa position déployée sous le colis.

To this end, the main object of the invention is a mechanical fall prevention system for a device for gripping heavy packages having an upper surface and a lower surface, the device comprising means for gripping the package by its upper surface, the fall prevention system acting on the bottom surface of the package to prevent any failure of the gripping means and comprising for this purpose:

• a cage fixed by its upper part to the gripping device, and open in its lower part so as to be able to completely cover the package to be lifted;
• at least one latch mounted pivoting about an axis located below the center of gravity of the latch and fixed on the lower part of the cage, said latch having at its lower end a heel whose angle ≦ 90 ° is directed towards the 'inside the cage and which, by resting on the storage surface of the package, straightens the latch in its folded position thus allowing the removal of the package;
• at least one stop for locking the latch in its deployed position under the package.

Preferably, each latch is provided with a spring which forces the latch to assume the deployed position when the cage is raised.

A preferred embodiment of the spring is that it is in the form of a spring leaf.

In order to adapt to large and cylindrical packages, the cage of the fall prevention system preferably consists of an upper crown connected to the hub by arms and a lower crown connected to the upper crown by bars. and on which the latches are pivotally mounted.

In this case the latches can be pivotally mounted on the lower crown by means of removable supports.

Advantageously, the lower crown has at its end an internal chamfer which facilitates the introduction of the package into the cage.

List of Figures

• Figure 1, une vue générale du dispositif de préhension et du système anti-chute selon l'invention ;
• Figure 2, en coupe, la partie inférieure du système anti-chute selon l'invention pendant sa mise en place autour de l'objet ;
• Figure 3, en coupe, la partie inférieure du système anti-chute selon l'invention pendant la préhension de l'objet ;
• Figure 4, un détail d'une réalisation possible des loquets du système anti-chute selon l'invention.

The invention and its various technical characteristics will be better understood on reading the following description which is accompanied by four figures representing respectively:

• Figure 1, a general view of the gripping device and the fall prevention system according to the invention;
• Figure 2, in section, the lower part of the fall prevention system according to the invention during its implementation around the object;
• Figure 3, in section, the lower part of the fall prevention system according to the invention while gripping the object;
• Figure 4, a detail of a possible embodiment of the latches of the fall prevention system according to the invention.

Detailed description of an embodiment of the invention

Referring to Figure 1, the gripping device of course has means for gripping the objects under consideration. In this case, these gripping means consist of a suction cup 1, secured to a central hub 2 placed in the upper part of the device. This hub 2 is attached to a suspension cable 3 of the device in general. The hub 2 can be provided with a guide consisting of a polyethylene ring to ensure better sliding of the handling cable, not shown of the suction cup 1. Similarly, a flexible pipe not shown is provided to allow the setting in depression of this suction cup 1.

When the suction cup 1 is in the rest position, that is to say that the device does not lift any object, this suction cup 1 is relaxed, as shown in Figure 1. No package or object has been shown in this figure 1 with the gripping device.

Among the heavy objects to be handled using the gripping device are containers filled with materials to be permanently stored such as nuclear waste. Such containers are generally cylindrical. This is why the cage 40 of the fall prevention system according to the invention has a general cylindrical structure called cage 40.

This cage 40 is mainly composed of an upper crown 5 fixed to the hub 2 by means of several arms 4. In correspondence, the device comprises a lower crown 6 connected to the upper crown 5 by means of uprights 7, and on which are pivoted latches 10. The fall prevention system thus constituted can therefore be suspended by the cable 3 and placed above and around a cylindrical object to be grasped. The latter will be gripped by its upper surface, its lower surface resting on the ground or on any support.

According to the invention, the fall prevention system acts directly on the lower surface of the raised object of the latches 10, the operation and mounting of which are explained in detail with reference to the other figures.

Referring to FIG. 2, a parcel 15 to be seized can be distinguished resting by its surface 15A on the ground 16.

On the left side of this figure 2, there is shown the lower part of the device according to the invention. In particular, we can distinguish a vertical upright 7 fixed in the lower crown 6 which has a chamfer 26. There is also a latch 10 pivotally mounted in the lower crown 6 around a mechanical axis 11 being positioned horizontally so that the latch 10 can tilt vertically.

The latch 10 is fixed by a first end 10A to this axis 11 so that the end 10B remote from this axis 11 tends to automatically tilt towards the inside of the cage. Finally, it can be seen that on the left-hand side of this FIG. 2, the device according to the invention has been shown as not yet in contact with the ground 16. The arrow appearing on the vertical upright 7 symbolizes the prior descent movement of the cage 40 around the object 15.

By cons, on the right side of this figure 2, a lower part of the fall prevention system according to the invention has been shown for a few moments later, that is to say in contact with the surface of the ground 16. The latch 10 is always substantially vertical. There is, however, a slight change of orientation around the axis 11. In fact, there is provided in the lower end 10A of the latch 10 a heel 19. It consists of a small surface or a flat 17 which is perpendicular or preferably forming an acute angle with a so-called internal surface 18 of the latch 10 located opposite the object 15, so that the heel 19 formed by the intersection of this flat 17 with the internal surface 18 finds the first in contact with the ground 16. As shown on the right-hand side of this FIG. 2, it therefore follows a slight pivoting movement of the latch 10 around the horizontal axis 11. Thus, the upper end 10B of the latch 10 is slightly separated from the object 15 and allows any vertical movement relative to the object 15 and vice versa.

The assembly is completed, for each latch 10, by a spring 13. Its role is explained with reference to FIG. 3. This figure shows the same elements of the fall prevention system as in FIG. 2. On the part left, the device is in the same position as on the right-hand side of FIG. 2. The only difference between these two half-figures is that the object 15 is supported by the gripping means, namely the suction cup 1 of FIG. 1. On the other hand, the system is still in contact with the ground 16 by means of the latch 10.

On the right side of this figure, the system according to the invention is hoisted as shown by the arrow on the far right, placed on the vertical upright 7. In this way, the heel 19 of the latch 10 is no longer in contact with the ground 16 and the spring 13 fixed relative to the lower ring 6 tends to tilt the latch 10 towards the inside of the cage, below the object 15. In this way, the upper end 10B of the latch 10 is located below the object 15. For this purpose, provision is made , fixed relative to the lower ring 6, a pivoting stop 21 preventing the latch 10 from pivoting completely.

It is found that thus several latches 10 can be pivotally mounted in the lower ring 6 and prevent an accidental fall of the object 15 in the event that the gripping means have to suffer a failure.

Referring to Figure 4, an embodiment of the latch 10 is shown with its mounting on the crown 6. In fact, to facilitate the maintenance of such latches 10, one can provide a removable assembly fixing on the lower crown 6. A for this purpose, each latch 10 can be pivotally mounted about a horizontal axis 11 on a removable support 27. Each of these removable supports 27 can be positioned on the lower ring 6, on a recess or a shoulder 9 thereof, by means of fixing screws represented by hexagon socket heads 8.

The spring 13 is a leaf spring which can be screwed onto a tenon 20 of the removable support 27. The end 13A of the leaf of the spring, bearing against the latch 10 can be placed in a groove 14 of the latter to facilitate its guidance.

Example of picking up and dropping a container on a flat surface

• 1) The gripping device and the system according to the invention are brought above and around the container 15.
• 2) The lower ring 6 is centered around the container, guided by an internal chamfer 26 of the lower ring 6 and by the inclined position of the internal surface 18 of the latches 10.
• 3) The latches 10 are erased in contact with the container (see figure 2 on the left); they are completely retracted when the heel 19 of the latch 10 is in contact with the ground 16 (see FIG. 2 on the right).
• 4) The suction cup 1 comes into contact with the upper surface of the container 15 and takes hold of it (see figure 3 on the left).
• 5) When the suspension cable 3 is put in tension, the container 15 is first raised alone from a height slightly greater than the length of the latches 10, then the fall prevention system is raised in turn separating from the ground 16 the heel 19 of each latch 10 which then automatically pivots in the deployed position under the package 15 (see FIG. 3 on the right).
• 6) For the removal of the container 15, the latches 10 retract as soon as the heels 19 come into contact with the ground 16.
• 7) The container 15 is then deposited normally, the latches 10 being in the folded position, and the assembly comprising the gripping device and the anti-fall system can thus be removed.

Example of picking up and dropping a container on another container

• 1) The gripping device and the anti-fall system according to the invention are brought above and around the container 15 which rests on another identical container.
• 2) The lower ring 6 is centered around the container 15, guided by the chamfer 26 of the ring 6 and the inclined position of the internal surface 18 of the latch 10 (see FIG. 3 on the right).
• 3) When the cage descends, the latches 10 are erased in contact with the container 15 to be evacuated. At the end of the descent, the lower crown 6, fitted with its latches 10, covers the upper part of the underlying container.
• 4) The suction cup 1 comes into contact with the upper part of the upper container and grips the latter.
• 5) The container is then lifted, and the latches 10 are released in the deployed position as soon as they are no longer in contact with the underlying container remaining in place.
• 6) For depositing the container 15 on an identical container, the lower ring 6 is centered around the underlying container, guided by the inclined position of the internal surface 18 of the latch 10.
• 7) The latches 10 are erased in contact with the underlying container already in place.
• 8) The container 15 to be deposited comes into contact with the container already in place, and can therefore be deposited on the latter.
• 9) The assembly constituted by the gripping device and the anti-fall system can then be evacuated since the two identical containers, rigorously aligned axially, and remaining in contact respectively by their lower and upper surfaces, do not allow the latches 10 to to deploy themselves.

Claims (6)

Mechanical anti-fall system for a device for gripping heavy packages (15) having an upper surface and a lower surface (15A), the device comprising means for gripping the package (15) by its upper surface, the anti-fall system acting on the lower surface (15A) of the package (15) to counter any failure of the gripping device and comprising for this purpose: - A cage (40) fixed by its upper part to the gripping device, and open in its lower part; - At least one latch (10) pivotally mounted about an axis (11) located below the center of gravity of the latch (10) and fixed on the lower part of the cage (40), said latch (10) having at its lower end a heel (19) whose angle ≦ 90 ° is directed towards the inside of the cage (40); - At least one locking stop (21) of the latch (10) in its deployed position under the package (15). Anti-fall system according to claim 1, characterized in that the cage (40) comprises an upper crown (5) connected to the hub (2) by arms (4), a lower crown (6) connected to the upper crown ( 5) by bars (7) and on which the latches (10) are pivotally mounted. Anti-fall system according to claim 1, characterized in that the pivoting latches (10) are fixed on the lower part of the cage (40) by means of removable supports (27). Anti-fall system according to claim 2, characterized in that the lower ring (6) has an internal chamfer (26) at its end. Anti-fall system according to claims 1 to 3, characterized in that each latch (10) is provided with a spring (13) which pushes it into the deployed position. Anti-fall system according to claim 5, characterized in that the spring (13) is a leaf spring.

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