Underwater house
U United States Patent 11 1 1111 3,875,753  
 Ehlers Apr. 8, 1975 UNDERWATER HOUSE [56] References Cited [76] lnventor: Bernd Ehlers, Langstrasse 20. 623 l. UNITED STATES PATENTS Alwnhflin. a 1.195.317 8/1916 Woods (11/69 3,464.217 9/1969 Streit (ml/69 [22] 3.706.206 12/1972 Clark (HI/69 [2|] Appl. No; 499,086 3.712070 1/1973 Mucinnis M169 R l A D 63 U s ff am 7 Primur) E.rumi11er.lacob Shapiro 1 Commuduo of March Attorney. Agent, or FirmMolinare, Allegrelli, Newitt abandoned.  
 &amp; wllcoff [30] Foreign Application Priority Dara Mar. 111. 1971 Germany 2113226 57] ABSTRACT An underwater enclosure includes a flexible, air-filled 152] US. Cl 61/69 R waterproof skin anchored to the sea floor and mainl l 363C g /0() tained in position by a stainless steel framework at- [58] Field of Search... 6H6); 52/2; ll4/l6 E, tachcd m the skin.  
 3 Claims, 2 Drawing Figures UNDERWATER HOUSE This is a continuation of application Ser. No. 234,971, filed Mar. 15, 1972, now abandoned.  
 BACKGROUND OF THE INVENTION This invention relates to an underwater house which is open at the bottom like a diving bell.  
  Prior art underwater houses or enclosures are made from rigid and therefore correspondingly cumbersome casings of steel or plastic, which, because of their usual large dimensions and weight, can be transported only at considerable expense. Even then they must be positioned in water with the aid of a crane. Moreover, once such prior art enclosures are underwater, their position can be changed only by considerable expense. Diving bells are likewise heavy rigid structures and are similarly expensive to transport and use. Thus, known underwater houses and diving bells are, for the reasons given, unsuited for the requirements of the sport or scuba divers.  
  The invention seeks to solve the problem of developing an underwater house suited especially for sport divers, by providing a light weight house having small dimensions during transport, so that it can be handled by few persons and if need be, by only one person.  
 SUMMARY OF THE INVENTION In a principal aspect the present invention comprises an underwater house enclosure having a flexible, shaped, inflatable skin closed tightly on all sides with the exception of a bottom opening. A collapsible framework supports the skin. The underwater house can be folded in the manner ofa tent and transported. It provides divers with secure protection to a depth of about ten meters and and may be used for submarine observations or as a decompression chamber.  
  In one embodiment the shaped skin is bubble or pearshape and consists of a high-strength fabric coated on both sides, preferably, with plastic. Fabrics coated or laminated with elastomeric materials, for example, with rubber, are suited for the flexible skin utilized in the invention to satisfy the requirements of the skin including a sufficient tensile strength to compensate for the forces in both axial directions due to the depth of the water, gastightness, water-tightness and adequate resistance also to corrosive seawater. Materials which may be utilized for the shaped skin are skin materials of the type which are used for the erection of inflatable air tents. Additionally, the shaped skin can be formed polyvinyl chloride sheet reinforced with high-strength polyethylene terephthalate cord or fabric.  
  Preferably the outer form of the assembled, shaped skin is constructed in the shape of an approximately hollow, upper spherically shaped dome with a lower truncated conical extension attached and tapering downward. It is not necessary that the bottom opening be circular. It can have any geometrical formation suit able for entry; for example, the lower part can be shaped as a rectangular, or preferably square, bottom opening.  
  The supporting framework includes a supporting hoop of metal, having a circular form, arranged, for example, to provide support at the line of transition between the dome and lower truncated part of the shaped skin. A bottom hoop, preferably of metal, is also connected as part of the supporting framework and several flexible and tension-loadable bars distributed about the circumference of the skin connect the hoops. The hoops are also fastened to the shaped skin. The two hoops can be laid flat upon each other and because they are different sizes can even fit into one another for transport of the device. The underwater house of the invention can, in practice, be folded into a compact package having the diameter of the supporting hoops. The flexible shaped skin and the flexible bars do not hamper folding of the enclosure.  
  The bars connecting the two hoops can be formed of interconnected sections of rigid bars or by chains or straps. Since the bars, are subjected only to tensile forces, one embodiment of the invention provides that the frame is formed form belts, cords or the like.  
  In order to make entry through the bottom opening possible, several legs may be attached to the bottom frame for support. The legs serve to anchor the underwater house in cooperation with weights fastened to the legs. To achieve stability, the legs can be arranged to have height adjustments. The stability and position of the house is also assisted by providing that the legs be bent outward to provide feet and increase the lateral stability.  
 BRIEF DESCRIPTION OF THE DRAWING Further details of the invention are explained in detail in the following figures:  
 FIG. I is a side view of the underwater house; and  
  FIG. 2 is a bottom view of the underwater house of FIG. I as seen from below below the enclosure.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT The assembled house or enclosure is represented in FIG. 1. It is formed when the shaped skin I is inflated like a balloon under water with an enclosed air bubble providing an expanding and upward action on the skin. In this position the approximately pearshaped form of the shaped skin I is derived from the hollow spherical shaped dome 2 and the attached hollow truncatedconical lower portion 3. A commercially available material for the shaped skin that has proven successful for air tents is P 2/2-Panama fabric coated on both sides with PVC, with high-strength polyethylene terephthalate threads having a denier in warp and weft of I,0O0/200/6OA (dtex 1,100), a setting (threads/cm) of l4/l4, a strength (kp/Scm) of 570 in the warp and 500 in the weft (woof), a stretch (percent) of IS in the warp and of 23 in the woof, a tear strength (kp) of 73 in the warp and 59 in the woof and a weight area (glm of l,l00.  
  Dome 2 and lower portion 3 are joined together as a single piece by cementing or otherwise connecting the dome 2 and portion 3. Viewing windows 4 and an air connection nipple 5 are installed in the dome 2 at desired locations.  
  The framework consists of the circular support hoop 6, a bottom hoop 7 with a square shape in the example shown, and flexible bars or straps 8 connecting the two hoops 6 and 7. The straps or bars 8 which are illustrated are capable of being subjected to considerable tension. These straps 8 are made, for example, of highstrength polyethylene terephthalate threads. Straps 8 are fastened at their opposite ends to eyelets 9 and 10 uniformly distributed about the circumference of the hoops 6 and 7. In the example illustrated twelve straps 8 are provided.  
  If the hoop 7 which defines a bottom opening 11 is circular in shape rather than square, as shown, the straps 8 can be arranged at equal angular intervals around the circumference of the respective circular hoops 6 and 7.  
  The upper supporting hoop 6, which is positioned at the transition or boundary between dome 2 and lower portion 3, absorbs the radially directed forces resulting from the upward force of the air bubble in dome 2. The hoop 6 is attached to the shaped skin 1 by insertion into tube or loop 12 on the outside circumference of the shaped skin 1. Only the eyelets 9 extend through appropriate openings in the loop 12. it is important that the loop 12 is securely fastened to the skin 1.  
  The shaped skin 1 is also fastened to the bottom hoop 7 by suitable clamping means. Attachment of the skin 1 to hoop 7 is especially important because the skin 1 together with the straps 8, transfers all upward-driving force on the skin 1 onto the bottom hoop 7.  
  The two hoops 6 and 7 are preferably made of stain less steel or plated steel to prevent corrosion. Similarly all the other metal parts of the underwater house of the invention are non-corrosive. The upper hoop 6 is preferably made from stainless steel tube whereas, as illustrated in the drawing, the bottom hoop 7, which serves simultaneously as an entrance and for support, is composed of bar shaped stock.  
  Four receiving sockets 13 are attached to bottom hoop 7, one socket at each corner. Sockets 13 extend perpendicularly downward from hoop 7 and are adapted to receive legs 14. Legs 14 extend down and outward and are preferably made of steel tubing. The legs 14 are elevationally adjustable by means of the clamping screws 15 associated with the receiving sockets 13. Anchoring of the underwater house is accomplished with the aid of the legs 14, which are weighted for this purpose with weights (not shown) fastened to them. The legs may also be fastened in any other suitable manner under the water. It is evident that the underwater house of the invention can be folded into a very compact space, especially since the legs 14 can be easily removed.  
  The invention is not restricted to the example described. The shaped skin I, for example, instead of being rounded can have edges. In such a case the supporting hoop 6 can also be constructed in a polygonal shape. Also the framework does not necessarily need to consist of only two hoops 6 and 7. Additional hoops may be provided for support of the skin 1. It is possible to construct the hoops 6 and 7 so that they can be taken apart. Moreover the hoops and framework may be replaced entirely by a neting which envelopes the shaped skin 1 like a captive balloon.  
  Instead of or in addition to the anchoring means described above including the legs 14, several anchoring eyelets 16 in FIG. 1 can be fastened to hoop 7. The underwater house can then be maintained in its underwater position by means of anchoring ropes or chains (not shown) through eyelets 16.  
  In a form of execution suitable for scuba divers, the underwater enclosure of the invention can have the following principal dimensions: maximum diameter L200 mm, entrance width of the bottom hoop 7 650 mm, and height between bottom hoop 7 and apex of the dome 2-l,600 mm.  
 What is claimed is:  
  l. A lightweight, portable underwater enclosure comprising, in combination:  
 a waterproof, flexible skin including an upper, semihemispherical portion and a downwardly extending, tapered portion, with the junction between said portions defining a continuous, substantially closed, circumferential loop in said skin, said flexible skin being a single sheet of plastic-coated fabric open only on the bottom; and  
 a lightweight framework including an upper, rigid,  
 closed, substantially circular support member attached to said skin through said loop at the junction between said upper, semi-hemispherical portion and said downwardly extending, tapered portion, a lower support member attached to said skin at the bottom thereof, and a plurality of non-rigid connecting means connected between said upper, substantially circular support member and said lower support member, said non-rigid connected means being resistive to tensile force;  
 said underwater enclosure having an inflated state wherein said skin defines a substantially pearshaped enclosure, said upper, substantially circular support member opposing the radial inward forces exerted on said skin by the buoyancy of said enclosure in said inflated state, and said non-rigid connecting means opposing the upward forces due to buoyancy exerted on said upper semihemispherical portion of said skin and directly transferring said forces to said lower support member, said material and shape of said upper, semihemispherical portion of said flexible skin alone defining means for sustaining said upper, semihemispherical portion in said inflated state, and said enclosure having a collapsed state wherein said flexible skin and said non-rigid connecting means are compactly folded and said upper, substantially circular support member and said lower support member are substantially planar, said upper, substantially circular support member having a sufficiently large diameter to circumscribe said lower, support member in said collapsed state.  
  2. An underwater enclosure as claimed in claim 1 wherein said plastic-coated fabric is polyvinyl chloride reinforced with a fabric of polyethylene terephthalate threads.  
  3. An underwater enclosure as claimed in claim 1 including a conduit through said skin for connection to an external gas supply.