TECHNICAL FIELD The present invention relates to a device of the kind set forth in the preamble of Claim 1.

BACKGROUND ART

Devices of this kind are used in many cases for delivering flowable bulk cargo e.g. grain, from the lower side of a suitably adapted container being situated at a certain height above a standing space, in which a tank vehicle to be loaded with the bulk cargo may be placed.

During such loading of e.g. a tank vehicle with flowable bulk cargo, which as mentioned above may be grain, or else sand, gravel, cement, flour, cocoa powder and many other materials, rather great quantities of dust will usually be developed, this dust both being capable of constituting a health risk for the personel in question, and - in the case of combustible dust - a not inconsiderable risk of explosion.

For this reason, in order to prevent the dust from escaping during the loading operation, exhaust filter assemblies has be developed, said assemblies having been placed on the lower side of the delivering container, the chute then having been moved downwardly to the lower side of the filter assembly. Al _l fi _l ter assemblies having been proposed for this purpose up to now have been constructed with fixed

dimensions, and it will be obvious that placing such a filter assembly between the lower side of the delivering container and the chute will reduce the available free height - this is not made less problematic by the fact that the tank vehicles have a tendency to increase in size.

DISCLOSURE OF THE INVENTION

It is on this background the object of the present invention to provide a device of the kind referred to initially, with which the available free height is substantially increased as compared to devices comprising a filter assembly with fixed dimensions, and this object is achieved with a device, according to the present invention exhibiting the features set forth in the characterizing clause of Claim 1. The fact that also the filter assembly is collapsible or telescopic in the vertical direction makes it possible to achieve the desired increase of the available free height.

A number of advantageous embodiments of the device according to the present invention, the effect of which - to the extent that it is not self-evident - is explained in more detail in the following detail part of the present specification, are set forth in Claims 2-7.

BRIEF DESCRIPTION OF THE DRAWING

In the following specification, the present invention will be explained in more detail with reference to the drawing, in which

Figure 1 is a vertical longitudinal section through

the device in a hypothetical operational situation, while Figure 2 shows the device in a collapsed position of rest.

DESCRIPTION OF THE PREFERRED EMBODIMENT The device shown in the drawing for delivering flowable bulk cargo (not shown), e.g. grain, consist of two main components, viz. - an axially collapsible chute 1, and a filter assembly 2, likewise collapsible in the axial direction.

When in use, the device is placed on the lower side of e.g. a granary or a grain bin (not shown), so that an opening in the bottom of the granary or grain bin debouches in the upper end of an inlet tube 3, the lower end of which debouches in the chute 1, the lower end of the latter ending in an outlet cone 4. The outlet cone 4 rests in an opening in a roof 5 in a tank vehicle (otherwise not shown) for transporting grain.

Thus, the filter assembly 2 and the chute 1 serve to guide the grain flowing out from the granary or grain bin (not shown) down into the tank vehicle, of which as mentioned only the roof 5 is shown.

The filter assembly 2 is adapted to prevent escape of dust while the grain flows down through the filter assembly and the chute. To this end, the filter assembly 2 is constructed as an enclosure extending about the inlet tube 3, the lower end in which enclosure in the operating condition shown in Figure 1

is in open cummunication with the upper part of the chute 1 and the lower part of the inlet tube 3, whilst the upper end of the enclosure forms a suction chamber 6, the latter being connected through a suction conduit 7 with a suction fan or the like (not shown).

In order to prevent the dust, which the air being evacuated carries away from the transition region between the inlet tube 3 and the chute 1, from leaving the filter assembly 2 and thus escape to the atmosphere through the above-mentioned suction fan, a number of filter bags 9 are placed in the enclosure between the inlet tube 3 and the outer wall 8 of the filter assembly. Quite a large number of these filter bags 9 may be placed about the inlet tube 3, but only two of these are shown in the drawing.

As evident from the drawing, the interior parts of the filter bags 9 are situated on the downstream side of the flow of air being evacuated, for which reason dust coming from the flow of grain will be deposited on the upstream side, i.e. the outside of the filter bags 9.

The chute 1 is made collapsible in a manner known per se, its outer wall 10 being shaped with peripheral folds in such a manner, that it in fact constitutes a folding bellows. In order to protect the outer wall 10 against grain falling through the chute 1, a number of downwardly converging funnel rings lla-d are secured with intervening spaces to the outer wall 10, said funnel rings constantly urging the grain inwardly in a direction away from the inside of the outer wall 10. In the exemplary embodiment shown, the chute 1 comprises only four funnel rings lla-d, but in

practical use, the chute 1 will have a considerably greater length in relation to its diameter than here shown, and will hence likewise have a greater number of funnel rings, e.g. from eight to ten.

Those features of the device according ^, to the present invention up to now having been described in this detailed portion of the present specification, do at least in principle substantially belong to the present state of this art. The new and characteristic features of the device according to the present invention are to be found in the construction of the filter assembly 2, now to be described in a more detailed manner.

In contrast to previous filter asaemblies for use in devices of this kind, the filter assembly 2 according to the present invention is in principle telescopic or collapsible in the axial direction, i.e. in the vertical direction. This is achieved partly by shaping the outer wall 8 of the filter assembly as a folding bellows in the same manner as the outer wall 10 in the chute 1, and partly by likewise shaping and situating the filter bags 9 in such a manner, that they may be collapsed in the axial direction or vertical direction of the device.

This will be clearly evident by comparing Figures 1 and 2, the latter Figure showing the device with both the chute 1 and the filter assembly 2 in the collapsed condition. As evident from the drawing, the funnel rings lla-d belonging to the chute are constructed with such a large internal diameter, that they can be moved up around the lower part of the inlet tube 3 with ample clearance, so that the mutual dimensioning

of the inlet tube and the funnel rings does not constitute any hindrance when in the collapsed condition shown in Figure 1 against lifting the chute 1 to such a high level as the collapsed filter assembly as such will allow.

In order to prevent that the sub-atmospheric pressure in the suction chamber 6 makes the filter bags 9 collapse, the latter may - partly and in a manner known per se be provided with internal stiffening rings or the like (not shown) preventing radial collapse of the filter bag, and partly be provided with means to prevent the filter bags from collapsing axially, e.g. in the form of a sufficiently heavy weight 12 placed on or secured to the bottom of each filter bag, or else a securing member 13, with which the bottom of each filter bag is secured to a rigid matching ring 14 inserted between the outer walls 8 and 10.

The drawing shows only those parts being strictly necessary for understanding the present invention, other parts being omitted to make the drawing easier to grasp.

Of parts not shown that a device of the kind here shown normally will comprise, the following may be mentioned a number of hoisting cords with an associated manual or motor-driven winch, with which the outlet cone 4 may be lifted, thus collapsing the complete device, means for removing the collected dust from the outside of the filter bags 9, such as a vibrator,

a dust-collecting device etc., and a tapered plug or the like, with which the outlet cone 4 may be closed, when bulk cargo is not to be delivered through the device.

The present invention is, of course, not limited to the construction of the device shown as an exemplary embodiment on the drawing. Thus, the outer wall 8 of the filter assembly and the outer wall 10 of the chute may be "telescopic", i.e. in the form of a number of tubes or rings, that may be pushed into each other. The filter means may also be constructed otherwise than the bags 9 shown; thus, instead of a number of separate bags two peripheral filter walls may be used, which in a longitudinal sectional view corresponding to Figure 1 would appear almost in the same manner as the filter bags 9 shown here. Further, the filter means may - at least in theory - also be "telescopic", i.e. in the form of a number of tubes or rings of air-permeable material capable of being pushed into each other.

In the exemplary embodiment shown in the drawing, the inlet tube 3 is rigid and not telescopic or collapsible. It does, however, lie within the scope of the present invention to construct also this component in such a manner, that it may be collapsed or telescoped in the axial direction in a similar manner to the chute 1 and the filter assembly 2. If so, the funnel rings lla-d do not necessarily have to have such an internal diameter, that they may be placed around the inlet tube 3.

LIST OF PARTS