Easy to assemble, above ground extreme weather shelter

Abstract

A tornado shelter has a dome-shape, sheltering wall formed by a multiplicity of modular, hollow/cavitied wall panel units manually assembled together at respective peripheral edges by the mating engagement of interlocking, male and female portions. Each wall panel unit is a one-piece molding with opposed side wall portions in spaced apart, parallel relation defining between them respective containers with filler openings adjacent a top and containing a filler material of alternately water, a rheopectic fluid, gel or granular particles, thereby increasing impact strength and anchoring weight. Selected base panel units are formed with respective eyes receiving ground anchoring stakes. Panel portions can be laminates reinforced by wire mesh or KEVLAR integrally molded therein.

Claims

1. A kit for making a ground standing tornado shelter wall comprising a set of a multiplicity of loose-piece, modular, single-piece, empty, shell-form, wall panel units, hollow throughout, for transportation to an erection site and pre-configured and self-supporting for manual assembly together by a single person at respective peripheral edges when empty to erect at the site, a hemi-spherical, dome-shape, free standing, ground supported, framework of a people sheltering, tornado shelter wall, the hollow, wall panel units each comprising an interior, sheet-form, panel portion and an exterior, sheet-form, panel portion connected together at each peripheral edge of the interior and exterior, sheet-form, panel portions, locating the interior, sheet-form, panel portion and the exterior, sheet-form, panel portion adjacent in spaced apart, face-to-face relation so as to define opposite, major upright walls of a cavity providing respective empty containers that can receive and retain pourable ballast therein, a filler opening formed in each exterior panel portion adjacent a top thereof that can receive a pourable, filling ballast material therein when all the panel units have been so assembled together, such that ballast weight is distributed over the entire framework of the tornado shelter wall when all containers are filled thereby increasing impact strength and ground anchoring weight.

2. The kit of claim 1 wherein said respective peripheral edges are elongate and integrally formed with respective, complementary, elongate, interlocking, male and female portions extending therealong to enable the assembly together of adjacent panel units in mating engagement by edge on edge, relative longitudinal sliding movement.

3. The kit of claim 2 wherein the male and female portions are undercut in complementary fashion to prevent unlocking separation except by relative longitudinal sliding movement.

4. The kit of claim 2 further comprising means on panel units for attaching anchoring stakes to the assembly.

5. The kit of claim 4 wherein said means comprise eyes formed on selected wall panel units which provide a base of the wall.

6. The kit of claim 2 wherein the exterior, sheet-form, panel portions of at least some of the panel units comprise laminates of KEVLAR and plastics including at least one layer of PE and a polycarbonate.

7. The kit of claim 2 wherein the exterior, sheet-form, panel portions of at least some of the panel units comprise laminates of metal mesh and plastics including at least one layer of PE and a polycarbonate.

8. The kit of claim 1 further comprising means on panel units to attach anchoring stakes to the assembly, wherein said means comprise eyes formed on selected wall panel units which provide a base of the wall.

9. The kit of claim 1 further comprising an access door for closing a gap between adjacent panel units when assembled together.

10. The kit of claim 9 wherein the access door includes an outer frame with complementary, interlocking, male and female portions for mating engagement with adjacent panel units to close the gap.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side view of the tornado shelter dome;

(2) FIG. 2 is a front view of the outside/exterior face of a wall building panel unit;

(3) FIG. 3 is a cross-sectional view of a hexagonal panel taken along line III-III of FIG. 2;

(4) FIG. 4 is a cross sectional view of the shelter dome taken along line VI-VI of FIG. 6;

(5) FIG. 5 is a perspective view of an example of one type of anchor;

(6) FIG. 6 is a schematic perspective view of one side of the tornado shelter dome showing the anchors mounted to extend below ground level (omitted);

(7) FIG. 7 is a side view showing the impact zone strain from a 24 piece of wood;

(8) FIG. 8 is a diagrammatic front view of a panel unit showing the impact distribution from a 24 piece of wood travelling at 250 mph;

(9) FIG. 9 is a diagrammatic view of a test rig showing the manner in which the dome will absorb the impact of a small, wind-blown truck;

(10) FIG. 10 is a fragmentary, perspective view of the front exterior of the dome showing an outward opening door;

(11) FIG. 11 is a schematic, perspective view of a side of the dome showing the calculated amounts and locations of simulated impact and absorption forces able to be withstood by the tornado shelter dome;

(12) FIG. 12 is a schematic front view of an exterior face of a laminated outer panel portion showing KEVLAR reinforcement as the first, exposed, exterior/outside layer of lamination for impact resistance;

(13) FIG. 13 is a schematic, fragmentary, cross-sectional view of an outer, laminated panel portion with a layer of KEVLAR reinforcement as an intermediate layer, an outer layer of PE and an inside layer (not seen) of polycarbonate;

(14) FIG. 14 is a schematic, fragmentary view of a corner of an exterior face of an outer, laminated panel portion showing a reinforcement of square mesh as the first, exterior layer of lamination;

(15) FIG. 15 is a schematic, fragmentary, cross-sectional view of a front corner of an outer panel portion with a reinforcement of square mesh as an intermediate layer of lamination;

(16) FIG. 16 is a diagrammatic, exploded view of a laminated front, exterior panel portion with a first exterior layer of polycarbonate, a second, intermediate layer of reinforcing material such as mesh and a third innermost layer of cross-linked PE.

DESCRIPTION OF PARTICULAR EMBODIMENTS

(17) As shown in FIG. 1, the tornado shelter dome comprises a set of interlocking hexagonal panels 1, (FIG. 2), pentagonal panels 3, and trapezoidal panels 4, that together form a dome shaped safety shelter. Each panel 1 is hollow, comprising a cavity 7 (FIG. 3) enclosed by interior and exterior/outer, panel portions 13 and 14, respectively, which are spaced apart in parallel relation and, has a bunghole type filler opening 2 in the exterior panel portion 14 adjacent a top through which the panel can be filled by pouring a flowable material such as a non-Newtonian fluid, liquid, gel, or granular substance for energy absorption and added weight. Once constructed, he dome measures approximately 47.5 tall and has a (base) diameter of approximately 81.

(18) The panels can be interlocked together manually by mating engagement of interlocking tongues 5 and grooves 6 forming transverse panel sides joining opposed edges of the interior and exterior panel portions together. A single, outward opening door 16 (FIGS. 4 and 8) has a frame provided with complementary tongues and groove for interlocking with those on the panels.

(19) The door includes baffled ventilation holes to allow sufficient airflow and pressure stabilization. Affixed to the door periphery are multiple twist handles (not shown) that engage the frame and lock the door in place.

(20) As shown in FIG. 4, the dome interior provides sitting room space 8 for 4-6 adults.

(21) FIG. 6 shows the erected dome with multiple anchor eyes 15 on ground/slab engaging panels receiving respective threaded screw/augur type anchoring stakes 9 (FIG. 5) that extend below ground level.

(22) FIG. 7 shows the 24 strike zone 10 on one of the hexagon panels 1 required by FEMA for testing. Another simulation, (FIG. 8), shows the simulated impact absorption of a 24 piece of wood striking one of the panels at a speed of 250 mph. FIG. 9 shows a truck 11 being tossed against the constructed dome and the redistribution of force that causes the truck to absorb most pressure at the impact point 12 and crumbling around the dome.

(23) The tornado shelter dome is designed to withstand the multiple pressure and impact loads as indicated in FIG. 11. Simulations show that the dome can absorb windborne debris of up to 10,000 pounds as a small area impact and a large area impact, such as the rolling truck, of up to 20,000 pounds. The dome-shape enables the shelter to withstand tornado force side winds of up to 4,000 pounds total force. The stakes 9 are necessary for anchoring the dome to withstand up to 10,000 pounds of lift-off force.

(24) As described above, there are many obstacles for the average consumer in acquiring a storm safety shelter such as weight of materials, installation by a third party, difficulty of movement, and expense of relocation. The tornado shelter dome of the invention offers solutions to all of those obstacles.

(25) By using industry standard materials such as cross-linked polyethylene, and rotational molding manufacturing techniques, the main constituents of the invention will be inexpensive to manufacture. A molded material such as cross-linked polyethylene is impact and tear resistant. Combining with a liquid, gel, or granular substances results in an energy absorption system that is greater than steel. The molded plastic material does not deteriorate or require regular maintenance unlike steel structures that require ongoing maintenance (repainting) to prevent rust, and need to be repainted. The molded plastic material is be lightweight with the heaviest dome panel weighing approximately 28 pounds before filling material is added, and can be assembled by a single person.

(26) After erecting the dome, the user stakes it to the ground at as many as 10 different points (FIG. 6), by using stakes such as American Earth Anchors model PE46, (FIG. 5). 10 stakes could provide up to 10 times the required holding force to secure the shelter to the ground in the case of an F3-4 tornado depending upon soil type. The user can reference a stake chart to determine the appropriate type and number of stakes for the ground type. Stakes can be driven into the ground either by a ratchet wrench, a lever handle, or an impact wrench powered either pneumatically or electrically. Alternatively the dome may be attached to a concrete pad with cast in place bolts or drilled-in bolts.

(27) Once constructed and staked to the ground, the user will fill each panel through each bunghole 2 with a non-Newtonian fluid, liquid, gel, or granular substance to transform the hollow panels into high impact absorbing panels raising the weight of the shelter dome to approximately 2,000 pounds. The benefit of this design allows a single person to construct the dome while the panels are empty and then add the filler material. Some filler materials may require the customer to add a chemical mixture such as propylene glycol or glycerol with ph buffering compounds like potassium phosphate to prevent freezing and bacterial growth. The panels can be emptied with a transfer pump, and the dome can be easily disassembled for relocation. To provide additional waterproofing, a fitted cover made from nylon, canvas or other similar material may be attached over the dome. A capturing net may also be placed over the dome and anchored to the ground.

(28) FIG. 13 is a schematic, fragmentary, cross-sectional view of an outer, laminated panel portion with a layer 17 of KEVLAR reinforcement as an intermediate layer, an outer layer 18 of PE and an inside layer (not seen) of polycarbonate;

(29) FIG. 14 is a schematic, fragmentary view of a corner of an exterior face of an outer, laminated panel portion showing a reinforcement of square mesh 20 as the first, exterior layer of lamination;

(30) FIG. 15 is a schematic, fragmentary, cross-sectional view of a front corner of an outer panel portion with a reinforcement of square mesh 20 as an intermediate layer of lamination;

(31) FIG. 16 is a diagrammatic, exploded view of a laminated front, exterior panel portion with a first exterior layer 23 of polycarbonate, a second, intermediate layer 24 of reinforcing material such as mesh and a third innermost layer 25 of cross-linked PE.