Patent Application
20130019563
1. Field of the Invention
The present invention relates to storm shelters and more particularly to precast storm shelters.
2. Description of the Related Art
For dangerous storms such as hurricanes and tornadoes, safe emergency shelters protect persons and property from harm and destruction. Hurricanes and tornadoes have been recorded with wind speeds of over 250 mph, and tornadoes are capable of staying on the ground for more than one hour. Flying debris causes serious injuries, death, displacement, and millions of dollars in property damage. Regardless of these catastrophic results, relatively few effective measures of protection are available. In general, building construction codes (and testing thereof) are designed primarily to reduce damage to buildings and property. Human safety concerns, consequently, are often neglected. Thus, storm shelters are a necessary and viable option for protection from hurricane-force winds.
When hurricane warnings are issued, some homeowners choose not to evacuate, but instead to stay in their residence and wait for the hurricane to either subside or move into a different area. When tornado warnings are issued, there is usually very little time for individuals and families to go to community shelters, many of which do not allow pets, without which families may be reluctant to leave home. Evacuation that takes place in densely populated areas can be dangerous due to traffic and worsening weather conditions. As such, The National Tornado Forum has encouraged more people to build “safe rooms” (emergency shelters). The Federal Emergency Management Agency (FEMA) and the Federal National Mortgage Association (Fannie Mae) have programs and financing in place to encourage people to use a “safe room” or shelter in the event of a weather emergency.
Embodiments of the present invention address deficiencies of the art with respect to manufacturing a precast shelter. A precast shelter can be manufactured constructing an inner mold core to include exterior walls enclosing an interior space and a cap covering a top opening of the interior space, adding a base frame around a perimeter of the inner mold core using a set of base rails and reinforcing bar segments affixed to different portions of the base rails, horizontally placing a plurality of steel rods on top of the cap, connecting different ends of the horizontally placed steel rods to the reinforcing bar segments with vertically positioned steel rods, and placing an outer mold shell opposite an exterior surface of the inner mold core so as to define a cavity between an interior surface of the outer mold shell and the exterior surface of the inner mold core. The method can further include pouring concrete into the cavity and on top of the cap over the horizontally placed steel rods, waiting for the poured concrete to partially cure, and removing the outer mold shell and the inner mold core subsequent to partially curing the poured concrete to produce a unibody precast shelter.
Additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The aspects of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. The embodiments illustrated herein are presently preferred; it is understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown, wherein:
Embodiments of the present invention address deficiencies of the art with respect to the manufacture of precast concrete protective shelters. In an embodiment of the invention, a precast shelter can be manufactured by providing several steel forms arranged to create a mold. At a bottom portion of the mold, between an inner mold core (the inner form) and one or more outer forms, is a channel frame base or base frame. The base frame surrounds the inner form and sits flush against it and includes multiple, different base rails with multiple, different vertical segments of reinforcing bars attached to the top surface of different portions of the base rails. High-strength concrete can be added between the inner and outer forms so as to fill the channel frame base as well as different reinforcing bar and welded wire mesh added to and around the inner mold core. Once the concrete partially cures to a desired strength, the resultant shelter can be lifted from the inner mold core. In this way, a precast shelter can be manufactured rapidly, simply, and repeatedly.
Of note, the shelter created by the procedure described herein is a precast protective shelter or “safe room.” In other words, the terms are used herein interchangeably, but it should be noted that in some publications, there can be a difference, but usually only with respect to identifying or describing shelters that meet certain standards, for example International Code Council (ICC) 500 or the FEMA 320 and 361 guidance. For instance, in Design and Construction Guidance for Community Safe Rooms, FEMA P-361, Second Edition (August 2008), all shelters constructed to meet the FEMA 320 and 361 guidance are referred as safe rooms. By precast, it is meant that the shelter is pre-cast from reinforced concrete by pouring concrete or a structural equivalent into a cavity defined by an inner mold core and an outer mold shell. The precast shelter can then be shipped to a desired location for incorporation into a foundation. It is at the foundation site where the floor is prepared and poured. Of further note, preparation of the floor can include drilling holes in the concrete base (the foundation) through predrilled holes in several retaining plates. A bolt, such as a three quarters of an inch Simpson Strong-Bolt wedge anchor, is passed through the hole in each retaining plate to the holes in the concrete base. Welded wire mesh can then be secured to the horizontal reinforcing bar segments after which the concrete floor can be poured and allowed to partially cure. Upon the concrete reaches the desired minimum strength, a door or doors can be attached. For example, a panel door with three dead bolts and a latch can be installed for level “E” protection or a door with a steel frame that is capable of meeting local, state, or federal standards can be installed.
In further illustration,
In further illustration of the process of manufacturing a precast shelter as described in
The inner mold core 150 and the base 205 can be coupled by any method now known or later developed, including welding and/or fastening, such as with screws, pins, bolts, or the like. Additional structures (not shown), such as plates, brackets, beams, rods, and the like, can be present in the interior space of the inner mold core 150. Further, both the inner mold core 150 and the base 205 can be made of steel or other material capable of supporting the material used in making the shelter, for instance concrete. The dimensions of the inner mold core 150 can vary. Generally, the inner mold core 150 is sized to create finished shelters that range from approximately seven feet (width) by seven feet (length) by eight feet ten inches (height) to approximately seven feet (width) by thirteen feet (length) by eight feet ten inches (height). Of note the inner mold core 150 and corresponding base 205 can be of any size to accommodate the manufacture of a variety of shelter sizes. Of note, a finished shelter may be an additional four inches to eight inches larger in size per dimension to account for the roof and the floor of a finished shelter. Further, the inner mold core 150 can be coated with lubricant before the preparation of the inner mold core 150 begins.
If the inner mold core is to be coated with lubricant, it is usually done before a channel frame base or base frame 328 is added around the perimeter of the inner mold core 150, as shown in
Yet further, the placement and number of the vertical reinforcing bar segments 125 can vary. For example, vertical reinforcing bar segments 125 can be coupled to the base rail 130 approximately twelve inches apart, on center in some instances, but can also be set about six inches apart (also on center) at each corner, where a corner is formed by joining two base rails 130. Of note, the placement of any vertical reinforcing bar segments 125 provides additional structural strength. Also, vertical reinforcing bar segments 125 may be further set apart to allow for the placement of a door frame. Though the vertical reinforcing bar segments 125 can vary in length, each is typically about thirty inches long and about five-eights of an inch in diameter. Further, the vertical reinforcing bar segments 125 can be metal, including thermo-mechanical treated steel. The base frame 328 can be made of any material, for instance steel.
Once the base frame 328 is set, the frames 410A, 410B can be prepared and coupled to the inner mold core 150, as seen in
The placement of frames 410A, 410B is not limited to a specific location. For instance, a frame 410A can be placed on at least one side, such as exterior wall 214, and another frame 410B can be placed on a different side. The frames 410A, 410B can be made from a variety of materials, for instance steel 410A and wood 410B. Of note, the method of attachment of the frames 410A, 410B to the inner mold core 150 will depend on the frame used. For instance, if a steel frame 410A is used, the frame 410A can be fastened, for instance through welding, to the base frame 328. If a wood frame 410B is used, the frame 410B can be fastened to the inner mold core 150 with a connector 413. In another instance, a “dummy” door (steel or wood) can serve as a placeholder for a later installed door meeting any local, state, or federal requirements, for instance Federal Emergency Management Agency (FEMA) requirements for shelters. The connector can be a bolt, screw, pin, or other fastener. In addition, a plate or bracket 414 may also be used to secure the frame 410B to the inner mold core 150 through which a connector 413 is placed.
Regardless of frame-type, each frame 410A, 410B is coupled to a frame support 409A, 409B made of a like material. In this way, the frame support 409A, 409B ensures the opening created by the frame 410A, 410B retains its shape when concrete is introduced between the inner mold core 150 and the outer surrounding mold shell. The frame support 409A, 409B is not limited to a specific design, but, for instance, can be a single support bar, an additional frame with a support bar or bars, and multiple support bars. In addition, more support can be added to the steel frame 410A. For instance, in
In further illustration of the manufacturing process of a shelter,
In further illustration,
In further illustration of the manufacturing process of a shelter,
In an embodiment, two sheets of the welded wire mesh 754 are placed on each of the four walls and the top or cap of the inner mold core. A sheet of welded wire mesh 754 can be made of metal, for instance steel and are sized appropriately to match the forms being used. Each of the lower portions of the sheets of welded wire mesh 754 on the four sides of the inner mold core can be attached to the upper ends of the plurality of vertical reinforcing bar segments by fasteners. The upper ends of the welded wire mesh 754 on the four sides further can be attached (tied) to the horizontal (reinforcing) bars located at the top of the sides near the top of the inner mold core. The welded wire mesh 754 on the four sides can also be attached (tied) to the vertical (reinforcing) bars located along the sides of the inner mold core. Of note, the welded wire mesh 754 can be cut upon placement or before placement to leave clear the opening created by any frame (for a door or a window).
Upon the completion of the prepared inner mold core 751, at least one form 799 can be positioned and secured to the base 205. In an embodiment, a crane or similar type of equipment can be used to lift and position the form 799. In another embodiment, a hydraulic system can be used to move, place, and/or remove the forms 799 as well as the inner mold core 150. A person may also assist in positioning the form 799. In one embodiment, the form 799 can be L-shaped. In another embodiment, the form 799 can consist of separate pieces that are coupled together to create an L-shape or other shape to the dimensions desired. For example, a form 799, seven feet in length by eight feet ten inched in height, can be coupled to another form 799, also seven feet in length by eight ten inches feet in height, to make the L-shape. In even yet another embodiment, the form 799 can consist of a piece seven feet in length by eight feet ten inches in height coupled to a second piece two feet in length by eight feet ten inches in height (creating a form nine feet in length). Yet even further, the form 799 can include a first piece seven feet in length by eight feet ten inches in height coupled to a second piece four feet in length by eight feet ten inches in height coupled to a third piece two feet in length by eight feet ten inches in height (creating a form thirteen feet in length). This thirteen foot form 799 can be coupled to another piece seven feet in length by eight feet ten inches in height to create an L-shaped form. In another embodiment, a plurality of separate forms 799 can be secured to the base 205 and attached to each other to enclose the prepared inner mold core 751. In yet another embodiment, there can be a variety of separate forms of varying lengths, for instance seven feet, nine feet, eleven feet, and thirteen feet, each by eight feet ten inches in height that can be coupled to another form to create L-shaped forms of varying sizes.
Of note, multiple apertures in the bottom of the frame 763 allow multiple bolts 774 or other fastener to pass through both the frame 763 and apertures in the base 205. The bolts 774 can be tightened, thus allowing the form 799 to be secured to the base 205. A form 799 can include a frame 763 coupled to a plate 759. Frame 763 can be coupled to the plate 759 using various methods, which can include welding or fastening or a combination of both. The inside surface 796 of the plate 759 is flat (smooth). Multiple, different vertical beams 761A, approximately equally spaced along the plate 759, can be coupled to the opposite side of the inside surface 796. Multiple, different horizontal beams 761B, for instance H-beams, can be coupled to the frame 763 and can be coupled to the vertical beams 761A. Of note, the multiple, different horizontal beams 761B can aid in preventing the form 669 from bowing when concrete is added and as it partially cures. In one embodiment, there can be three horizontal beams 761B, where a first horizontal beam is placed at the approximate midpoint of each vertical beam 761A, so that the horizontal beam 761B is perpendicular to the vertical beams 761A. In addition, a second horizontal beam can be placed above the first horizontal beam, and a third horizontal beam can be placed below the first horizontal beam. Both the second horizontal beam and the third horizontal beam can be placed at equal distances from the first horizontal beam. In one instance, the second horizontal beam and the third horizontal beam can each be placed at about two feet from the first horizontal beam, though the placement of the second and third horizontal beams can vary. Of note, each horizontal beam 761B can extend pass the frame 763. In addition, each end of the horizontal beam 761B can have multiple, different openings 777. In this way, multiple, different bolts 774 can be passed through the different openings 777 of each horizontal beam 761B, thus connecting a second form 799 to the first form at the corners formed by the intersection of the horizontal beam 761B of one form 799 to the horizontal beam 761B of one another form 799. Of note, at least one eye 786 can be coupled to a horizontal beam 761B, usually a top horizontal beam 761B (or second horizontal beam) at the midpoint. An eye 786 can also be coupled to the frame 763, in one instance, at the top of the frame 763 at the approximate center or midpoint of the frame. The eye 786 enables a cable, chain, wire or similar attachment to pass through allowing a crane or similar device to move the form 799. Attaching the beams 761A, 761B to the frame 763 and of the beams 761A, 761B to another beam 761A, 761B can be done with any method now known or later developed, including but not limited to welding and fastening. In addition, the size of the beams 761A, 761B, the frame 763, and the plate 759 can vary depending on the size of the shelter to be manufactured.
Once a form 799 is placed, at least one tapered wedge 744 can be placed through openings 777 in the horizontal beam 761B and the apertures 209 in the base 205 to align, position, and hold the form 799 in place, while another form 799 is disposed atop the base 205. Once placed, any forms 799 can be coupled to one another with multiple, different bolts 774 passed through the multiple, different openings 777 at the ends of each horizontal beam 761B as seen in
Upon the removal of the forms, the shelter 906 can be lifted from the base 205 and the inner mold core 150 using multiple, different jacks 1009, as illustrated in FIG. 10A. Of note, before the separation process begins, any brackets with connectors securing the frame supports 409A, 409B to the inner mold core 150 are removed. A crane can be attached to the lifting eyes, which are accessible through the lifting eye apertures, with multiple, different clutch rings 1036. Each jack 1009 can then be inserted into place at the base 205, as further illustrated in
Once the shelter 906 is free, the crane can set the shelter 906 down so that horizontal reinforcing bar segments (headed studs) 1102 and retaining plates 1106 can be added to the interior of the shelter 906, as shown in
Upon the installation of the retaining plates 1106 and the horizontal reinforcing bar segments 1102, the pre-cast shelter 1299 is ready to be placed on a foundation (see
When not protecting individuals from the catastrophic damages resulting from tornadoes, hurricanes, and other hazards, it is envisioned that the shelter can serve other purposes. A precast shelter can be incorporated into the construction of a home, added to an existing home, or serve as a free standing structure able to withstand significant wind velocities and damage that occur from power storms, such as hurricanes an tornados. The protective shelter can be dry-walled and finished as any other room in the home and used accordingly. For example, the shelter can be used as a storage room, a walk-in closet, a vault, a hobby room, a sewing room, bathroom, pantry, laundry room, or a wine storage room.
While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. The invention has been described with respect to certain preferred embodiments, but the invention is not limited only to the particular constructions disclosed and shown in the drawings as examples, and also comprises the subject matter and such reasonable modifications or equivalents as are encompassed within the scope of the appended claims.
The application is a Continuation-in-Part of U.S. application Ser. No. 13/187,229, currently pending, filed Jul. 20, 2011, which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13187229 | Jul 2011 | US |
| Child | 13588074 | US |
