Device for adjustment of the height of an airship
BACKGROUND OF THE INVENTION 
     The present invention relates to airships, and in particular to apparatus for adjusting the height of an airship, the apparatus including a floating body of tube-like supporting gas containers and air bags. 
     In airships known up until now, the supporting body comprises one or more tube-like supporting gas containers and air bags arranged inside each container. When several containers are used they are not interconnected, but are mutually free. Air is supplied via air lines for filling the bags. In the present state of the art, for internal air bags, only local variations in air pressure, temperature, etc., can be compensated for, i.e. neither fuel, nor load (i.e. available load), which are usually compensated for by sandbags or the like can be compensated for without use of such means. 
     SUMMARY OF THE INVENTION 
     The object of the invention is thus to provide a floating body with a relationship between strength and weight such that trimming required by air pressure and temperature can be carried out and the available load can be compensated within the capacity of known materials. 
     This object is attained with the apparatus in accordance with the present invention, which is distinguished in that the air bags are disposed outside of and between the supporting gas containers such as to join the latter to each other, and in that the apparatus includes at least one fan-compressor means for high pressure and/or at least one fan-compressor means for low pressure. 
     The apparatus is further distinguished in that each air bag contains one or more cells. 
     In a preferred embodiment of the apparatus, the floating body includes at least three supporting gas containers, defining by their air bags an interior space for supporting gas. 
     In another preferred embodiment of the apparatus, the floating body includes at least four supporting gas containers, and the interior space may include at least-one further-air bag dividing the space into at least two smaller, longitudinal spaces. In addition, there can be envisaged six, seven, eight, etc., separated supporting gas containers. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     The invention will now be described in more detail below, and with reference to the accompanying drawing, wherein. 
     FIG. 1 is a vertical transverse cross-section through a first embodiment of the apparatus, the air bags not being filled with compressed air. 
     FIG. 2 illustrates the same arrangement as in FIG. 1, but with the air bags filled with compressed air. 
     FIG. 3 schematically illustrates a second embodiment of the apparatus. 
     FIG. 4 schematically illustrates a third embodiment of the inventive apparatus, and 
     FIG. 5 a fourth embodiment of the apparatus. 
    
    
     DETAILED DESCRIPTION 
     As will be seen from FIGS. 1 and 2, the apparatus for adjusting the height of an airship in accordance with the invention is a floating body 1 which comprises a plurality of horizontally, longitudinally elongated supporting gas containers 2, arranged side-by-side and which become tube-shaped due to interior excess pressure, and a plurality of horizontally, longitudinally elongated air bags 3 arranged side-by-side relative to one another and relative to the supporting gas containers 2, which air bags 3 may be filled, for reducing the height of the airship, with copressed air from a fan compressor means 8 connected thereto, and for increasing height may be vented by valves 9 on the air bags. The supporting gas containers 2 and air bags 3 are made from a flexible but unstretchable material, and preferably of the same material. Due to the use of several smaller supporting gas containers instead of a large one, and air bags which are each divided into several cells 4, the assortment of woven fabrics available for them is widened, since less excess pressure is required. It is particularly emphasised that there is thus provided the opportunity of selecting a woven fabric of low weight, which, of course, considerably facilitates both manufacture and height adjustment. By the air bags 3 being disposed outside and between the supporting gas containers as well as connecting the latter to each other, there is also obtained the advantage that the total weight of the floating body may be increased or decreased, while simultaneously decreasing or increasing its supporting gas volume, resulting in more effective height adjustment than that obtained by supporting gas containers solely having internal air bags, where it is merely possible to increase or decrease the total weight. 
     The second embodiment of the apparatus illustrated in FIG. 3 comprises three supporting gas containers 2, each having an air bag 3 meeting at a common point, the third embodiment of the apparatus illustrated in FIG. 4 and also having three containers 2 with their individual air bags is one where the containers 2 define an interior space 5, which may be filled with supporting gas, thus increasing the lifting capacity of the floating body. 
     The fourth embodiment, illustrated in FIG. 5, of the apparatus comprises four supporting gas containers 2, each with an air bag 3 and defining an interior space 5, as with the apparatus of FIG. 4, and a further air bag 6 can be used to divide this space into two smaller, longitudinal spaces 7. Finally, one or more of the air bags 3 and 6 can be permanently filled with compressed air, in which case they serve as stiffening beams.