The present invention relates generally to protective shelter structures, and more particularly to a subterranean tornado shelter.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention in sufficient detail to enable one of ordinary skill in the art to which the invention pertains to make and use the invention.
The shelter 10 may be moved to an installation site without ballast material 28 in the cavity 26, and may be placed in a desired location that has been excavated to accommodate the shelter 10. Thereafter, the cavity 26 may be filled with an insulative or ballast material 28. Accordingly, the unfilled cavity 26 minimizes the weight of the shelter 10 and facilitates transportation and handling of the shelter 10 prior to installation.
In the embodiment shown, the exterior surface of the base 12 comprises a first portion 30 having a generally frustoconical shape that gradually becomes wider in a direction from the open upper end 20 of the base 12 toward the lower end 32 of the base 12. A second portion 34 of the exterior surface extends radially, outwardly from the first frustoconical portion 30 and has the general shape of an oblique rectangular prism which extends from the lower end 32 of the base 12 to the open upper end 20. The exterior surface of the base 12 includes a plurality of ribs 36 extending generally from the lower end 32 of the base 12 toward the open upper end 20. The ribs 36 are spaced apart circumferentially around the perimeter of the base 12 and define pockets 38 therebetween. The arrangement of ribs 36 and pockets 38 helps to strengthen the structure of the base 12, and the sloped exterior walls help to anchor the base 12 below the ground surface 40 (
Referring to
The shelter 10 further includes a closure 50 joined to the open upper end 20 of the base 12 to thereby enclose the chamber 14. In the embodiment shown, the closure 50 is rotationally molded from polymeric material and has a double wall construction, similar to that described below for the base 12. To provide strength and rigidity to the structures of the rotationally molded base 12 and closure 50, various portions of the base 12 and closure 50 may be strengthened with “kiss-offs” 52, 54 disposed between oppositely facing walls of the base 12 and/or closure 50, as depicted in
The peripheral shape of the closure 50 comprises a generally circular portion 56 and a generally rectangular portion 58 extending generally radially therefrom, to correspond to the open upper end 20 of the base 12. The closure 50 may include ribs 55 or other structure to provide strength and resist deformation under load. The closure 50 may be joined to the open upper end 20 of the base 12, for example, by extrusion welding, joining with adhesive or fasteners, or by any other method suitable for coupling the closure 50 to the open upper end 20 of the base 12.
Referring to
The shelter 10 further includes a door assembly 70 coupled to the passageway 60, generally at the upper edge 72 of the upper walls 62a, 62b, 62c, 62d. The door assembly 70 comprises a generally rectangular doorframe 74 which may be secured to the upper edge 72 of the passageway 60. A door 76 is hingedly coupled to the doorframe 74 and can be moved between a closed position (
With reference to
The shelter 10 further includes a stairway 46 extending from the chamber 14 and through the passageway 60 to facilitate entering the chamber 14 and exiting the chamber 14 through the passageway 60. In the embodiment shown, the stairway 46 comprises ladder-type structure including a plurality of rungs 100 spaced apart in a vertical direction and extending from the chamber 14 upwardly through the passageway 60. The rungs 100 are supported in the chamber 14 by generally vertically extending chamber stringers 110a, 110b that are integrally formed with the chamber sidewalls 18. As seen in
The passageway 60 also includes passageway stringers 114a, 114b disposed on oppositely facing portions of the upper walls 62a, 62c generally above the chamber stringers 110a, 110b such that the stairway 46 extends upwardly from the chamber 14 and through the passageway 60. The passageway stringers 114a, 114b have pairs of notches 116 for supporting rungs 100 in a generally vertically spaced direction to provide a continuation of rungs 100 from chamber 14.
The door assembly 70 may also include one or more rungs 100 provided on the door 76 such that the stairway 46 extends outwardly from the passageway 60 when the door 76 is in the open position. In this embodiment, the rungs 100 are secured to the door flanges 84a, 84b and are spaced apart in a generally vertical direction to provide a continuation of the rungs 100 from the passageway 60. Accordingly, the door 76 may be moved to the open position and locked in place with the cylinders 78, for example, whereby persons may enter or exit the chamber 14 using the rungs 100 provided in the chamber 14 and passageway 60, and on the door 76.
Behind the rungs 100 of stairway 46 and within the recess 44 defined by the protruding rectangular prism portion 34 of the base 12 is a space 120. This space 120 may be used as a storage area for tools, equipment, or provisions for persons using the shelter 10 during an emergency, such as during a tornado.
Referring now to
While the present invention has been illustrated by the description of an embodiment thereof, and while the embodiment has been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of the general inventive concept.
This application claims priority to pending U.S. Provisional Patent Application No. 60/886,206, filed Jan. 23, 2007, which is incorporated by reference herein in its entirety.
Number | Date | Country | |
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Parent | 60886206 | Jan 2007 | US |
Child | 12017668 | US |