SAFE ROOM II

Abstract

A method for manufacturing a precast shelter is provided. The method can include constructing an inner mold core, adding a base frame around a perimeter of the inner mold core, horizontally placing a plurality of steel rods on top of the inner mold core, connecting different ends of the horizontally placed steel rods to reinforcing bar segments of the base frame with vertically positioned steel rods, and placing an outer mold shell opposite the inner mold core so as to define a cavity. 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.

Description

CROSS-REFERENCE TO RELATED APPLICATION

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.

BACKGROUND OF THE INVENTION

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.

BRIEF SUMMARY OF THE INVENTION

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.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

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:

FIG. 1 illustrates the process of manufacturing a precast shelter;

FIG. 2 is a perspective view showing an embodiment of an inner mold core on a base used to manufacture a shelter;

FIG. 3 is a corner view of the inner mold core showing dead bolt anchors (reinforcing bar segments) fixed to a base rail;

FIG. 4A is a perspective view showing the inner mold core on a base with two frames;

FIG. 4B is a corner view showing the inner mold core on a base with two frame mountings;

FIG. 5 shows lifting eyes along an exterior wall of the inner mold core;

FIG. 6 is a perspective view of the inner mold core;

FIG. 7A is a perspective view of the prepared inner mold core;

FIG. 7B depicts a form being placed on the base around a prepared inner mold core;

FIG. 7C shows the coupling of two forms with the assistance of a tapered wedge;

FIG. 7D shows the coupling of two forms with bolts;

FIG. 8 shows the top or roof of a shelter after concrete has been poured in a cavity between the inner mold core and the outer mold shell;

FIG. 9 illustrates the removal of a form revealing the shelter;

FIG. 10A illustrates the separation of the shelter from the base and the inner mold core using jacks;

FIG. 10B is a close-up showing the separation of the shelter from the base and inner mold core using jacks;

FIG. 11A illustrates the addition of retaining plate and bolts in order to prepare the shelter for placement on a foundation; and,

FIG. 11B is a close-up of a bolt used in preparation of the shelter for placement on a foundation; and,

FIG. 12 is a perspective view of a completed shelter ready for placement on a foundation.

DETAILED DESCRIPTION OF THE INVENTION

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, FIG. 1 illustrates the process of manufacturing a precast shelter. As shown in FIG. 1, an inner mold core 150 can be constructed to include exterior walls enclosing an interior space and a cap covering a top opening of the interior space. The inner mold core 150 can be surrounded 152 with a base frame. Of note, the base frame can include multiple, different (steel) reinforcing bar segments 125 welded to a channel base rail or base rail 130. Multiple, different steel rods can be placed 166 around the inner mold core 150, upon the placement of the base frame. Concrete can be poured 178 into a cavity created between the exterior surface of the inner mold core 150 and the interior surface of an outer mold shell after the outer mold shell is placed opposite the exterior surface of the inner mold core 150. A precast shelter can be produced 182 after waiting for the poured concrete to partially cure to a desired strength.

In further illustration of the process of manufacturing a precast shelter as described in FIG. 1, FIG. 2 shows an embodiment of an inner mold core 150 on a base 205 used to manufacture one embodiment of a precast shelter. More specifically, the inner mold core 150 is skid mounted. The inner mold core 150 is composed of a plurality of plates that can each be coupled together to form a house-like structure with four sides and a top, which is further coupled to a base 205. In other words, an inner mold core 150 can be constructed to include exterior walls 214 enclosing an interior space and a cap 204 covering a top opening of the interior space. The base 205 can contain multiple, different apertures 206, 209. Apertures 206 can be positioned at the approximate corners of the base 205 and are configured to allow jacks to be inserted into the base 205 after the shelter has been formed (after the concrete has been poured and partially cured). In this way, jacks can assist in lifting the shelter from the inner mold core 150. In an embodiment, there are four apertures 206, thus allowing the placement of four jacks. Additional apertures 209 can be configured along the top surface of the base 205. The apertures 209 can be of such size and shape to allow fasteners, such as bolts, to pass through enabling the coupling of any forms used to form the outer mold shell to the base 205.

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 FIG. 3. In other words, the base frame 328 is disposed on top of the base 205 and around the inner mold core 150, thus surrounding the inner mold core 150. The base frame 328 can be one piece or made of multiple sections coupled together after placement atop the base 205. Caulk 335 can then be applied around the base frame 328 to ensure a non-leak seal between the base frame 328 and the inner mold core 150. Of note, the frame base 328 can include a channel frame 329, which can include a set of base rails 130, for instance four base rails 130, in a configuration that matches the inner mold core 150 at the base of the inner mold core 150, and multiple, different vertical dead bolt anchors (DBAs) or reinforcing bar segments 125 that can be welded, on center, into the channel bottom of the base rails 130. The base rails 130 can take the form of substantially C-shaped channels with each base rail 130 having a pair of top edges and a channel bottom section defined between the pair of top edges. Of further note, a side surface of the frame base 328 is in contact with (or flush with) a side surface of the inner mold core 150. The frame base 328 (and thus, the base rails 130) can vary in length in order to match the size of the inner mold core 150 being used. The base rail 130 can vary in width, but in one embodiment, the base rail can be approximately four inches in width. Further, in an embodiment, each side of the base rails 130 can be about one and three quarter inches in height, but in other embodiments, the height of the base rail 130 can be approximately flat or can have a height of at least one and three quarter inches up to six inches.

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 FIG. 4A. FIGS. 4A and 4B show the inner mold core 150 on a base 205 with two frames 410A, 410B and the support 409A, 409B for each frame 410A, 410B as well as (steel) vertical rods 430A coupled to several vertical reinforcing bar segments 125. Specifically, the lower ends of the multiple, different vertical rods 430A can be attached to the upper ends of the plurality of vertical reinforcing bar segments 125 by multiple fasteners 462. Each fastener 462 can be a wire tie or any other type of fastener that secures a vertical rod 430A to a vertical reinforcing bar segment 125. The coupling of any structure, including any rod, such as 430A, 530B, to another structure by a fastener can be according to local code, ASTM (formerly American Society for Testing and Materials) standards, Federal Emergency Management Agency (FEMA) specifications, or other code. Of note, each corner can include three vertical rods 430A adjacent to each other, as illustrated in FIG. 4B. In addition, additional vertical rods 430A can be arranged around the inner mold core 150.

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 FIG. 4B, multiple, different support rods 416 (shown with one support rod 416) can be coupled to the frame 410A. The support rods 416 can be used to position a frame 410A appropriately in later-poured concrete as well as serve as a tie down spot for additional structure, such as welded wire mesh. FIG. 4A shows multiple, different apertures 416 in the frame 410A configured to accept the support rods 416. The support rod 416 can vary in size, but, in one embodiment, it is about eight inches in length and has a diameter of about one-eighth of an inch. In addition, the support rods 416 are located on both sides of the frame 410A. The frame support 409A, 409B can be coupled to each frame 410A, 410B in a variety of methods, including but not limited to welding, fastening (with screws, bolts, pins, nails, or the like), and taping. Of note, a polystyrene frame 411 can be coupled, with tape 412, for instance, to a wood frame. The polystyrene frame 411 can aid in preventing the formed concrete shelter from adhering to the wood frame 410B during separation of the shelter from the inner mold core 150. In addition, caulk 335 can be applied around the wood frame 410B as well as between the base frame 328 and the inner mold core 150, as indicated above. In this way, the caulk 335 prevents leaks. Of note, both frames 410A, 410B are suitable so that an attached door will withstand extreme wind speeds, for instance, two hundred fifty mile per hour wind speeds. In addition, each frame 410A, 410B with an attached door is capable of meeting the requirements for Federal Emergency Management Agency's (FEMA's) projectile test for level “E”, Essential Facilities. In addition, the steel frame 410A with attached door meets the Federal Emergency Management Agency (FEMA) 361 Projectile Test requirements. Of further note, the frames 410A, 410B and their corresponding support 409A, 409B can vary in size to allow for different sized openings, such as doorways (shown) or windows (not shown). In one embodiment, the opening created by a frame 410A, 410B for use as a doorway can be about six feet six inches in height and about three feet in width and a window opening can be about thirty seven inches in width and about twenty six inches in height.

In further illustration of the manufacturing process of a shelter, FIG. 5 shows the addition of lifting eyes 575 along the roof line or top edge of a side, for instance exterior wall 214, of the inner mold core 150. After multiple, different horizontal (steel) rods 530B are placed along the top edge of the inner mold core 150, multiple, different lifting eyes 575 can be coupled to the horizontal rods 530B using an E-rod or bent rod 565 that has been passed through the opening in the lifting eye. The bent rod 565 as well as the lifting eye 575 can additionally be coupled to the horizontal rods 530B and the vertical rods 430A, as appropriate, with a plurality of fasteners 462. Of note, the coupling of any rods (bent 565, horizontal 530B, vertical 430A, etc.) will be done as required to meet code, including, but not limited to fastener type and overlap requirements. In other words, the lifting eye 575 with the coupled bent rod 565 is not coupled to all horizontal and vertical rods 530B, 430A. The lifting eyes 575 allow for the finished shelter to be transported. Each lifting eye 575 acts as an anchor for a crane or other suitable piece of equipment to hoist the shelter onto a truck or position the shelter on a footing or foundation at a construction site. Of note, in one embodiment, there are four lifting eyes 575 placed along the roof line of an exterior wall 214. Of further note, the lifting eyes 575 can also be coupled to the horizontal rods 530B (see FIG. 6) placed on the roof or cap 204 of the inner mold core 150.

In further illustration, FIG. 6 shows the inner mold core 150 with the addition of a multiple, different spacers 616 on the cap 204 and sides of inner mold core 150 as well as multiple, different horizontal (steel) rods 630C placed on top of the roof or cap 204. The horizontally placed rods 630C are placed in such a way to be in line with some of the previously placed vertical rods 430A. The horizontal rods 630C and the vertical rods 430A can be coupled with fasteners. The roof rods 630C can also be coupled to the horizontal rods 530B. Of note, the spacers 616 ensure the welded wire mesh holds its place in the center of the concrete. In addition, additional rods 630D can serve as door rods, which can be placed horizontally at the top of each frame 410A, 410B. FIG. 6 also shows four lifting eyes 575 as well as a plurality of support rods 416 coupled to the steel door frame 410A.

In further illustration of the manufacturing process of a shelter, FIGS. 7A and 7B depict a form 799 being placed on the base 205 around a prepared inner mold core 751. The prepared inner mold core 751 can include, but is not limited to, the base frame, multiple, different rods—including horizontal, vertical, door, roof, and support rods—spacers, frames, frame support, fasteners, and lifting eyes. Of further note, the different rods can act as reinforcing rods. In addition, the prepared inner mold core 751 can include welded wire mesh 754 coupled to the different of rods using multiple, different fasteners. The weld wire mesh 754 can be an electric fusion welded precast reinforcement consisting of a series of parallel longitudinal wires with accurate spacing welded to cross wires at the required spacing. Generally, machines with precise dimensional control are used to produce the mesh.

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 FIGS. 7C and 7D. All forms 799 can also be coupled to the base 205 with bolts 774 through apertures 209 in the base 205 and bottom of the form 799. Of note, at least one of a plurality of forms 799 can be coupled to another form 799 to form an outer mold shell. In other words, the outer mold shell can consist of a multiple, different of forms 799; each form 799 can be coupled to another form 799. Upon the securing the forms 799 to the base 205, any ventilation or electrical duct work on the roof can be done prior to pouring concrete into a cavity and on top of the cap or roof, covering the horizontal rods.

FIG. 8 shows the roof 804 of a shelter after concrete has been poured and partially cured between the inner mold core and the mold shell 842 upon both securing the forms 799 and completing the addition of any ventilation and/or electrical duct work. For example, openings or apertures 871 on the roof 804 can permit an air vent. Further, the apertures 871 can permit heating, ventilation and air conditioning (HVAC) ductwork to be installed within the shelter. Additional openings can be designed to permit the installation of electrical conduits to be installed within the enclosed space (the interior) of the shelter. It is supposed that a single opening could accommodate HVAC and electrical conduits. Further, in the event that an opening (doorway or window, for example) is blocked by debris resulting from a tornado, hurricane or other hazard, an additional opening can be cast for the inclusion of a hinged escape door which then serves as another exit route. Other openings may also be designed to permit the installation of plumbing inside a shelter. In some instances, some openings can include reinforcing bars along all or some of the edges of the opening. For example, an opening that serves as a window or doorway may include the placement of two additional reinforcement bars at all or some of the edges of the opening and one diagonal reinforcement bar at each of the top corners of the opening. Of note, the mold shell 842 can consist of a plurality of forms. In other words, at least one of a plurality of forms can be coupled to another form to create the outer mold shell 842.

FIG. 8 further shows venting apertures 871 and lifting eye apertures 866 as well as eyes 786, allowing a crane to be coupled to the structure. The high-strength concrete is inserted into the cavity (the space) between the inner mold core and the mold shell 842. Specifically, after the outer mold shell is placed opposite an exterior surface of the inner mold core, so as to define a cavity between an interior surface of the outer mold shell 842 and the exterior surface of the inner mold core, concrete can be poured (pumped and/or bucketed) into the cavity and on top of the cap over the horizontally placed rods. Of note, the cavity contains the vertically positioned steel rods as well as the base frame. Of further note, besides concrete, including reinforced concrete, any material that satisfies the requirements set by regulatory bodies for “safe rooms” may be used to create the shelter. Of further note, the mold shell 842 is formed upon the coupling of at least one form to another form and the forms being coupled to the base. Concrete can be placed into the cavity by any means, such as by pumping, pouring, or by bucket. During concrete placement, the concrete should be added in such a way that the concrete is brought up equally on all sides. The concrete is vibrated after is it added to remove air pockets, but should not be over-vibrated as to cause segregation. Of note, as the cavity is filled with concrete, samples of the concrete can be taken for testing to ensure the concrete will meet strength requirements when cured. After the cavity is filled to the top edge of the mold shell 842, the roof 804 should be smoothed. In this way, each fastener and rod is encased in concrete. A tarp can then be added atop the concrete filled mold shell to aid in drying and curing and to protect it during inclement weather. The concrete should cure to the recommended strength after about twenty-one to twenty-four hours. Of further note, the partially cured concrete at the twenty-four hour concrete test should have a measured strength of about three thousand (3000) pounds per square inch or higher before the outer mold shell 842 is removed.

FIG. 9 illustrates the removal of a form 799, revealing the shelter 906, after the concrete partially cures. Before any form 799 is removed, any bolts or other fasteners securing the form 799 to the base must first be removed. Clutch rings of a crane or similar equipment is coupled to the form 799 via an eye or eyes before the form 799 is removed. Shelter 906 is shown as rectangular in shape and is comprised of a front wall 912, a back wall (not shown), a left side wall (not shown), a right side wall (not shown), and a roof 804. Other shapes and configurations of shelter 906 are possible as well, in accordance with alternative embodiments of the present invention. For instance, a shelter can be cylindrical shaped, thus requiring the various components, such as the inner mold core and outer mold shell, to be cylindrical shaped or at least curved to produce a cylindrical shaped shelter. Other size and dimensional characteristics are also contemplated and within the scope of the invention, as shelter 906 may be specifically configured to fit within any home.

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 FIG. 10B. Specifically, each jack 1009 is placed at the approximate corner of the base 205 under the corner of the base frame and aligned in such a way that, upon extension of the jack 1009, the jack 1009 extends through the aperture 206 seen in FIG. 2. Each jack 1009 can be coupled to a manifold that can be coupled to a hydraulic pump. The manifold ensures that equal pressure is applied to each jack 1009. The size of each jack 1009 is not limited as long it has the ability to free the shelter 906 from the inner mold core 150. In one embodiment, each jack 1009 is a twenty five ton jack 1009. Of note, in an embodiment, there can be four jacks 1009: one placed at each corner. Of note, a crane keeps pressure on the shelter 906 to assist in determining when the shelter 906 breaks free from the inner mold core 150 as the jacks 1009 are extended. Of further note, on average it takes about six to twelve inches of lift (extension) by the jacks 1009 to separate the shelter 906 from the inner mold core 150. Of even further note, extension blocking on the jacks 1009 may be needed, especially in the first several uses of the molds. Once the shelter 906 is free, it can be set down.

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 FIGS. 11A and 11B. Specifically, horizontal reinforcing bar segments 1102 and retaining plates 1106 can be welded to the base frame 328 in the interior of the shelter 906. The multiple, different horizontal reinforcing bar segments 1102 can be deployed at various positions throughout the base frame 328. For example, horizontal reinforcing bar segments 1102 typically can be deployed at two foot intervals. Of note, in one embodiment, a horizontal reinforcing bar segment 1102 can be a reinforced steel rod eight inches in length with a diameter of five-eighths of an inch. In another embodiment, a horizontal reinforcing bar segment 1102 can be a reinforced steel rod six inches in length with a diameter of three-quarters of an inch. A retaining plate 1106 can be placed at each interior corner of the shelter 906 and welded to the base frame 328 (for a total of four retaining plates 1106). The retaining plate 1106 can be an eight inch by eight inch by one-half inch steel plate with at least one drilled hole that allows the insertion of at least one fastener, such as a three-quarter of an inch Simpson Strong-Bolt wedge anchor or equivalent, into the concrete base.

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 FIG. 12). Of note, once the pre-cast shelter 1299 is placed and properly located on a foundation, additional work, including the set-up and pouring of the concrete floor can take place. The pre-cast shelter 1299 can withstand wind speeds of at least two hundred fifty miles per hour as well as the impact of a projectile, such as a wood board missile, traveling horizontally at up to and including one hundred miles per hour and vertically at up to and including sixty seven miles per hour. The wood board missile can be a fifteen pound two by four. Of further note, shelters 1299 can be coupled together to form a community safe room. For example, a community safe room can consist of fourteen individual safe rooms coupled together in a variety a configurations, for instance in a two by seven configuration. Each shelter can be modified as necessary to meet the needs of a community. For instance, at least one safe room can be configured as a bathroom.

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.

Claims

1. A method of manufacturing a precast shelter, the method comprising:

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;

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 cavity containing the base frame and the vertically positioned steel rods;

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.

2. The method of claim 1, further comprising attaching a plurality of lifting eyes to at least one of the horizontal placed steel rods.

3. The method of claim 1, further comprising securing a plurality of welded wire mesh sheets to at least one of the horizontal placed steel rods.

4. The method of claim 1, further comprising securing a plurality of welded wire mesh sheets to at least one of the vertically positioned steel rods along at least one exterior wall of the inner mold core.

5. The method of claim 1, wherein removing the outer mold shell and the inner mold core subsequent to partially curing the poured concrete to produce a unibody precast shelter, comprises:

inserting a plurality of jacks in a support base, wherein each jack is aligned with an aperture in the support base, the aperture being located at the approximate corner of the support base;

extending the jack until the shelter is released from the inner mold core.

6. The method of claim 1, wherein the inner mold core is rectangular shaped.

7. The method of claim 1, wherein a base rail includes a substantially C-shaped channel having a pair of top edges and a channel bottom section defined between the pair of top edges.

8. The method of claim 1, wherein an outer side surface of the base frame is flush with the exterior surface of the inner mold core.

9. The method of claim 7, wherein the end of each plurality of reinforcing bar segments is welded on center on a top surface of the channel bottom section of at least one base rail of the plurality of base rails.

10. The method of claim 1, wherein waiting for the poured concrete to partially cure further comprises waiting for a sample of the poured concrete to reach a desired strength of at least three thousand pounds per square inch when measured at a twenty-four hour concrete test, the sample taken during the pouring of the concrete into the cavity.

11. The method of claim 1, wherein the unibody precast shelter withstands wind speeds of at least two hundred fifty miles per hour.

12. The method of claim 1, wherein the unibody precast shelter withstands a wood board missile traveling horizontally at up to and including one hundred miles per hour and vertically at up to and including sixty seven miles per hour.

13. The method of claim 12, where the wood board missile is a fifteen pound two by four.

14. The method of claim 1, further comprising forming a community safe room by coupling a plurality of unibody precast shelter.