You are an expert at summarizing long articles. Proceed to summarize the following text:

You are an expert at summarizing long articles. Proceed to summarize the following text: 
CROSS REFERENCE TO RELATED APPLICATION 
     This is a Continuation-In-Part of U.S. patent application Ser. No. 09/821,397 filed Mar. 29, 2001, now U.S. Pat. No. 6,485,231, which is a Continuation-in-Part of U.S. patent application Ser. No. 09/386,791 filed Aug. 31, 1999, now U.S. Pat. No. 6,287,050, which is a Continuation-In-Part of U.S. patent application Ser. No. 09/079,611 filed May 15, 1998, now U.S. Pat. No. 5,944,445, which claims the benefit of provisional application number U.S. Pat. 60/052,819 filed Jul. 10, 1997. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to flood water control devices for enclosed areas below base flood plain levels, and more particularly, to flood water control devices for venting enclosed spaces within a foundation, garage, foyer, an entry, basement or other such area. 
     BACKGROUND 
     To help limit flooding damage, several building code organizations and the federal government have promulgated regulations that mandate that buildings with enclosed spaces located below base flood plain levels, such as crawl spaces, must provide for automatic equalization of interior and exterior hydrostatic forces caused by flooding fluids such as water. According to these regulations, flooding fluids must be permitted to enter and exit the enclosed spaces freely. In particular, many of these regulations require builders to install a number of vents in the enclosed spaces. For example, federal regulations require flood venting for all new construction in flood-prone areas and where renovations to an existing structure exceed fifty percent of the value of the property. 
     In addition to the regulations mentioned above, good construction practice embraces the use of vents which can be opened during warmer months to allow for ventilation to permit moisture to escape from crawl spaces, while retaining the ability to close during colder months to prevent the circulation of cold air around exposed plumbing in crawl spaces. Typically, the use of screening and louvers is necessary to achieve both the warm weather and cold weather requirements of proper venting and is required by at least some building codes for openings in foundation walls. As a result, a flood vent must be able to automatically remove the louver and screen barrier when confronted with free-flowing, flooding fluids. 
     Generally, a wide variety of devices have been developed which may be utilized to provide pressure relief from both liquid and gaseous forces. With respect to gas pressure relief devices, U.S. Pat. No. 3,680,239, issued Aug. 1, 1972 to Burtis for PRESSURE EQUALIZING VALVE, discloses a device to relieve overpressure and underpressure in the opening and closing of a door of a refrigerated space. U.S. Pat. No. 2,774,116, issued Dec. 18, 1956 to Wolverton for DOUBLE ACTING RELIEF VALVE, U.S. Pat. No. 2,798,422, issued Jul. 9, 1957 to Bourque for AIR RELIEF MEANS FOR DOORS, and U.S. Pat. No. 3,123,867, issued Mar. 10, 1964 to Combs for VESTIBULE PRESSURE EQUALIZER, relate to the equalization of differential air pressure experienced in the swinging of one door relative to another door. Additionally, U.S. Pat. No. 2,105,735, issued Jan. 18, 1938 to Hodge for PRESSURE RELEASING APPARATUS, and U.S. Pat. No. 4,116,213, issued Sep. 26, 1978 to Kamezaki for AIR PRESSURE CONTROL APPARATUS FOR A HOT OR COLD STORAGE CHAMBER, teach methods to release pressure in closed chambers resulting from changing temperatures within the chamber. In particular, the Kamezaki apparatus utilizes a swinging damper hinged at the top of an enclosing frame. Nevertheless, neither the Kamezaki apparatus nor other inventions contemplate the use of a vented damper able to relieve pressure resulting from fluid flow. 
     Correspondingly, several devices have been developed which provide relief from overpressure resulting from the flow of water and other liquids. U.S. Pat. No. 4,349,296, issued Sep. 14, 1982 to Langeman for IRRIGATION DITCH GATE, describes a gate for an irrigation ditch, which during normal conditions through the use of tensioned springs, maintains flood gates in a closed position, but upon flood conditions, allows for the gates to open. U.S. Pat. No. 3,939,863, issued Feb. 24, 1976 to Robison for BASEMENT SUMP CONSTRUCTION, discloses a basement drain containing a trap for the prevention of back flow of flood water. U.S. Pat. No. 4,174,913, issued Nov. 20, 1979 to Schliesser for ANIMAL GUARD FOR FIELD PIPE, relates to an invention which, while allowing for the free-flow exit of debris carrying effluents from an open pipe end, prevents animal entry into the pipe. Still, none of the aforementioned devices contemplate the integration of a liquid flow control device with a temperature controlled ventilation system. 
     Presently, several patents disclose methods for ventilating enclosed foundation spaces. U.S. Pat. No. 5,293,920, issued Mar. 15, 1994 to Vagedes for LOUVERED BASEMENT VENT, and U.S. Pat. No. 5,487,701, issued Jan. 30, 1996 to Schedegger et al. for PLASTIC FOUNDATION VENT, embody louvered basement vents which can be manually adjusted to limit air flow in colder temperatures and to maximize air flow in hotter conditions. U.S. Pat. No. 5,460,572, issued Oct. 24, 1995 to Waltz et al. for FOUNDATION VENTILATOR, discloses merely a one-piece molded plastic foundation ventilator without louvers. The Waltz invention, however, contemplates the manual use of hinged doors to regulate air flow through to the foundation. U.S. Pat. No. 2,754,747, issued Jul. 17, 1956 to Bertling for AIR REGISTER OR LOUVER, embodies a hinged, louvered door designed to facilitate the maintenance of the screen behind the louvered door. Nonetheless, the louvers are designed to be operated manually by the user. 
     All of the aforementioned foundation ventilators contain screening to prevent small animals and other pests from gaining access to the enclosed area, as required by the model building codes for openings in foundation walls. Significantly, none of the aforementioned foundation ventilators will act as a pressure relief valve in response to the ebb and flow of flooding fluids. Furthermore, few provide for the automatic adjustment of louvers in a flood gate in response to increasing or decreasing temperature so as to prevent either the rotting of the elements of the structure&#39;s foundation or the freezing of pipes within the enclosed space. Accordingly, the prior art has not provided an integrated apparatus that automatically ventilates an enclosed space of a foundation, allows for the relief of fluid pressure on either side of the vent and prevents small animals and other pests from entering the enclosed space. 
     SUMMARY OF THE INVENTION 
     The subject invention has advantages over all current air vents now used and provides a novel and nonobvious opening for the entry and exit of flooding fluids such as water. The low-maintenance flood vent can be installed in new and existing crawl spaces and foundations and can remain in use year round. These vents have particular utility in areas designated by the Federal Emergency Management Agency (FEMA) as flood prone areas. When installed, the vent will allow for the free passage of air ventilation in warm temperatures and the temperature controlled louvers will close fully in colder temperatures. 
     Also, the louvered panel will be screened to prevent penetration by small animals and other pests and will operate like a pivotally connected gate. The panel can be secured in the closed position by a latching mechanism that senses the height and the direction of the flow of fluid surrounding the vent and releases the panel at a predetermined height. 
     A vent in accordance with an inventive arrangement can remain open for regular air ventilation in warm weather conditions, can close to block off air flow during cold weather conditions and can, at any time, open to enable the passage of flooding fluid into and out of the crawl space. 
     The present invention relates to a flood gate. The flood gate includes a frame defining a fluid passageway therethrough and a door pivotally mounted in the frame for rotation between a plurality of open positions to permit flow of fluid therethrough. The flood gate also includes at least one latching mechanism for holding the door in the closed position. The latching mechanism senses the fluid force acting on the door and releases the door when the fluid force meets a preset level. 
     In one aspect of the invention, the latching mechanism include a float to determine the level of the fluid force. In addition, the float can be disposed within the door. In this arrangement, the door can contain at least one aperture for permitting the fluid force to act upon the float. 
     In another arrangement, the flood gate can have a sensing and releasing device which can sense the fluid force acting on the float and can release the door when the fluid acting on the float meets the preset level. In addition, the frame can define an open slot adjacent the float. Further, the sensing and releasing device can be a pin extending from the float, and the pin can be adapted to be inserted into the open slot. Positioning the pin within the open slot can prevent the door from pivoting. 
     In another arrangement, the open slot can include an opening in which the position of the opening determines the preset level. When the fluid force acting upon the float meets the preset level, the pin can exit the opening of the open slot and the pin can be unconstrained by the open slot. This can enable the door to rotate between the open positions. In addition, the frame can define a channel which can enable passage of the pin through the frame when the door rotates between the open positions. In another aspect, the latching mechanism can reset the door to the closed position when the fluid force acting on the door drops below the preset level. 
     In another arrangement, the flood gate can include at least one stake for attaching the flood gate to a structure. Each stake can include a longitudinal member and an attachment portion. In another aspect, the frame can define a tine slot for receiving the longitudinal member in which the longitudinal member can be insertable into the tine slot in one direction and resistant to removal in an opposite direction. 
     In yet another aspect, the frame can define opposing door slots in which the door slots include opposing door pins respectively positionable within the opposing door slots. Each door slot can include a bottom which can define a resting vertical and horizontal position of the door pins upon insertion into the door slots. In addition, each door slot can include a door slot opening which can be positioned above the resting vertical and horizontal position. Also, each door pin can be respectively pivotable within the door slot. 
     In another aspect of the invention, the door can include a ventilation opening, an automatic louver assembly for controlling air flow through the ventilation opening and a screen covering the ventilation opening. In one arrangement, the automatic louver assembly can open and close in response to ambient temperatures. The automatic louver assembly can have at least one louver, a temperature sensitive actuating device and a member connecting the louver to the temperature sensitive actuating device. 
     Another aspect of the invention includes a bracket for preventing the flood door from opening when the structure in which the flood door is mounted, such as an overhead garage door, is rotated or moved from a generally vertical position to a generally horizontal position. The bracket operates by preventing the locking mechanism from releasing and allowing the flood door to open. In one embodiment, the bracket is an arm that is rotatably mounted to the flood door or frame. As the frame of the flood door is rotated with the structure in which the flood door is mounted, such as an overhead garage door, the bracket rotates around a pivot point and prevents the float from moving. Prohibiting the float from moving prevents a locking pin from being removed from an open slot, and therefore, prevents the flood door from opening. 
     These and other features and advantages of the present invention will become apparent after review of the following drawings and detailed description of the disclosed embodiments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Presently preferred and alternative embodiments of the inventive arrangements are shown in the drawings, it being understood, however, the inventive arrangements are not limited to the precise arrangements and instrumentalities shown. 
     FIG. 1 a  is a front elevation of a door of a flood vent according to the invention. 
     FIG. 1 b  is a side elevation of the door in FIG. 1 a.    
     FIG. 2 a  is a front elevation of a frame of a flood vent. 
     FIG. 2 b  is a side elevation of the frame in FIG. 2 a.    
     FIG. 3 is a side elevation of a flood vent inserted into a wall and stakes for attaching the flood vent to the wall. 
     FIG. 4 shows the stakes of FIG. 3 inserted into a frame of the flood vent. 
     FIG. 5 is an expanded sectional side elevation of a stake attached to a wall. 
     FIG. 6 is an expanded partial side elevation of the stake in FIG. 4 inserted into a frame of a flood vent. 
     FIG. 7 is a sectional elevation of the door in FIG. 1 a.    
     FIG. 8 is a detailed side elevation of a temperature sensitive actuating device. 
     FIG. 9 a  is a cross section taken along line  9 — 9  in FIG. 7 showing louvers in a closed position. 
     FIG. 9 b  is a cross section taken along line  9 — 9  in FIG. 7 showing louvers in an open position. 
     FIG. 10 is a front elevation of a flood vent showing louvers in a closed position. 
     FIG. 11 a  is a cross-sectional side elevation of a flood vent showing the reaction of a float to an increasing or a decreasing fluid level. 
     FIG. 11 b  is a cross-sectional side elevation of a flood vent showing a door swinging open after a float has released the door. 
     FIG. 12 a  is a front elevation view of a float according to another preferred embodiment of the invention. 
     FIG. 12 b  is a side elevation view of the float illustrated in FIG. 12 a.    
     FIG. 12 c  is a top plan view of the float illustrated in FIG. 12 a.    
     FIG. 12 d  is a bottom plan view of the float illustrated in FIG. 12 a.    
     FIG. 13 is a front elevation of a door frame according to another embodiment of the invention. 
     FIG. 14 a  is a cross-sectional side elevation of a flood vent according to another embodiment of the invention showing the position of a float therein when the flood vent is in a closed position. 
     FIG. 14 b  is a cross-sectional side elevation of the flood vent in FIG. 14 a  illustrating a pin being raised from a pin slot by the force of flowing fluid. 
     FIGS. 14 c-f  are cross-sectional side elevations of the flood vent in FIG. 14 a  sequentially illustrating the sequential opening of a door by the force of flowing fluid. 
     FIG. 15 is a side elevation of a door and a frame before insertion of the door into the frame. 
     FIG. 16 a  is a side elevation of a door and a frame showing the positional relationship of the door to the frame during insertion of the door into the frame. 
     FIG. 16 b  is a side elevation of a door and a frame illustrating the positioning of the door in FIG. 16 a  to a closed position. 
     FIG. 17 a  is a cross-sectional side view of another vent including a bracket. 
     FIGS. 17 b-d  are cross-sectional side views of the embodiment shown in FIG. 17 a  showing the embodiment in various positions during operation while the structure in which the embodiment is mounted is rotated. 
     FIG. 18 is a cross-sectional side view of another vent including a bracket. 
     FIGS. 19 a-f  are cross-sectional side views of a vent including a bracket shown in various positions during operation while flood water passes through the frame. 
     FIG. 20 is a cross-sectional front view of a vent having a solid flood door including two brackets. 
     FIG. 21 is a front view of modular stacked vents having a solid doors. 
     FIG. 22 is a side view of the vents of FIG.  21 . 
     FIG. 23 is a partial-sectional front view of a vent having an insulated solid flood door including two brackets. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 2 illustrate a vent  8  according to a preferred embodiment of an inventive arrangement. The vent  8  can have a frame  10  formed from a corrosion resistant material, preferably stainless steel. The frame  10  is not limited as to a particular dimensioning; however, in one arrangement, the frame  10  can be in dimensions of 8″×16.″ In the one embodiment, the top rail  12  and the bottom rail  14  each can be approximately 17{fraction (11/16)}″ long, and the side rails  16  can be approximately 9{fraction (11/16)}″ long. 
     A door  22  can be attached to the frame  10  so that the door  22  can pivot relative to the frame  10 . Many features capable of pivoting the door  22  relative to the frame  10  are well known in the art, and all such features are acceptable for use with this invention; however, the presently preferred features to attach the door  22  to the frame  10  are door pins  86  which can extend from sides of the door  22 . The door pins  86  can be adapted to be received within door slots  88  which can be disposed within the frame  10 . As shown in FIG. 2 b , the door slots  88  can be T-shaped. This configuration can allow the door pins  86  to rise in the door slots  88  which can permit the door  22  to rise in response to flooding. Significantly, however, the design of the door slots  88  can prevent the door  22  from being easily removed during flooding conditions and can deter entry by unauthorized persons or pests. 
     The door  22  is preferably made with a corrosion-resistant material, most preferably stainless steel. The door  22  also preferably comprises two mesh grilles  24  which can be disposed on opposing faces of the door  22 . Although the mesh grilles  24  can allow air to pass through the door  22 , the size of the openings in the mesh grilles  24  can be sufficiently small to prevent objects such as small animals, as required by model building codes for openings in foundation walls, from passing through the door  22 . 
     Any means of securing the frame  10  to a wall opening is acceptable. An example of a securing means is a set of stainless steel set screws. Divots can be drilled in the building prior to insertion of the setting screws to ensure proper security. Also, the perimeter can be caulked as required. 
     As illustrated in FIGS. 3-6, a presently preferred means of securing the frame  10  to a wall  17  is with one or more stakes  11 . The stakes  11  can include a forked longitudinal member  13  and an attachment portion  15 . The attachment portion  15  can be bent at predetermined positions based on the thickness of the wall  17 . Thus, the wall  17  can be wedged between the frame  10  and the bent portion of the attachment portion  15 . The attachment portion  15  preferably includes a slot or hole through which a fastener, such as a nail or screw, can be inserted into the wall  17  thereby securing the frame  10  to the wall  17 . The forked longitudinal member  13  preferably includes a pair of tines  19 ; however, the invention is not so limited, as the forked longitudinal member  13  can contain any number of tines  19 . 
     The tines  19  can be configured to be inserted into a slot  23  in the frame  10  in one direction but resistant to removal in the opposite direction. The number of slots  23  contained in the frame can be based on the number of stakes  11  included in the invention; however, any number of slots  23  can be contained in the frame  10 . Any feature on the tines  19  that resists removal in an opposite direction is acceptable; however, the presently preferred feature is one or more teeth  21 . The teeth  21  can be externally mounted on the tines  19 , as shown in FIGS. 3 and 6. It should be noted, however, that the invention is not limited in this regard, as the teeth  21  can be can be internally mounted on the tines  19  such that the teeth  21  on opposing tines  19  will face towards each other. In this arrangement, each tine  19  containing the internally mounted teeth  21  can be inserted into an appropriately sized slot  23  or pair of slots  23  in one direction but resistant to removal in the opposite direction. 
     The teeth  21  can also be both externally and internally mounted on the tines  19 . In this arrangement, the frame  10  can include one or more slots  23  for receiving one or more tines  19  containing both internally and externally mounted teeth  21 . Similar to the previously discussed teeth  21  arrangements, each tine  19  with both internally and externally mounted teeth  21  can be inserted into an appropriately sized slot in one direction but resistant to removal in an opposite direction. As shown in FIG. 6, each tooth  21  can be configured with a first contact surface  25  and a second contact surface  27 . In one arrangement, the width of the forked longitudinal member  13  is greater than the width of each slot  23 , and the distance  24  between the tines  19  is at least as great as the difference between the width of the forked longitudinal member  13  and the width of each slot  23 . 
     In a preferred embodiment, each of the first contact surfaces  25  can be oriented at an angle relative to the direction the stake  11  is to be inserted into the slot  23 . Further, each of the second contact surfaces  27  can be oriented substantially perpendicular to the insertion direction of the stake  11 . Pressure from inserting the stake  11  into the slot  23  against the first contact surface  25  can force the tines  19  towards one another and can enable the stake  23  to be inserted into the slot  23 . Also, because the second contact surface  27  can be oriented substantially perpendicular to the insertion direction, the second contact surface  27  can prevent removal of the stake  11  from the slots  23 ; however, the stake  11  can be removed from the slots  23  if the tines  19  are forced together such that the combined width of the tines  19  and teeth  21  is less than the width of the slots  23 . 
     This preferred embodiment of the attachment means has several advantages. Specifically, no tools are needed to install the device. In addition, since the door  22  can be completely removed from the frame  10  during installation, maintenance, cleaning or removal, access to the inner surface of the wall  17  can be achieved without entering the structure. During installation, the frame  10  can be placed in a prepared opening in the wall  17 . The stakes  11 , which can be bent based on the thickness of the wall  17 , can then be positioned through the opening in the frame  10  with the bent attachment portion  15  of the stake  11  placed behind the wall  17 . Further, the forked longitudinal member  13  of the stake  11  can be inserted into the slot  23  of the frame  10 . As a result, the wall  17  can be secured between the frame  10  and the stake  11 . The installation process can then be repeated for each of the remaining stakes  11 . These stakes can then be anchored to the wall  17  with a fastener, such as a screw or nail. Once the frame is secured to the wall  17 , the door  22  can be installed in the frame  10 . 
     Once attached to the wall  17 , the frame  10  can be difficult to remove. However, if the frame  10  does have to be removed for maintenance or any other purpose, forcing the tines  19  together can enable the stakes  11  to be removed from the slots  23  and can thereby allow the frame  10  to be removed from the wall  17 . Because this is a difficult and nonobvious process, however, it can discourage removal of the frame  10  by unauthorized persons. 
     FIGS.  7  and  9 - 10  illustrate the substantially equally spaced positioning of louvers  58  within a door frame  28 . Although these drawings illustrate the door frame  28  as containing four louvers  58 , the invention is not so limited. In fact, the door frame  28  can contain any number of louvers  58 . A vertical rod  60 , preferably made from a corrosion-resistant, strong material such as stainless steel, can be coupled to each louver  58 , as shown in FIGS. 9 a  and  9   b . Referring to FIG. 8, the vertical rod can be coupled to a temperature sensitive actuating device  36 . The temperature sensitive actuating device  36 , so named because the device translates thermal inputs into physical motion, can be adjusted to drive the louvers  58  open through vertical rod  60  during warm temperatures and to substantially fully close the louvers  58  through vertical rod  60  when the temperature falls below approximately forty degrees Fahrenheit. In one arrangement, the temperature sensitive actuating device  36  can be a bimetallic coil. It should be noted, however, that the invention is not limited in this regard, as the actuating device  36  can be wax elements, thermal pistons, thermal bellows, a snap acting disc or leaf, a thermal diaphragm, a helical coil or a spiral band or mechanism utilizing electronic sensors and motorized actuators or any other suitable temperature activated device. 
     FIG. 7 illustrates the latching mechanism  70 . The latching mechanism  70  can operate by sensing the level or flow of fluids, such as water, passing through the door frame  28  and, at a preset level, can release the door  22 . At a time when the level of fluid has decreased sufficiently so that the door  22  hangs substantially perpendicular to the ground, the latching mechanism  70  can be reset, which in turn can return the door  22  to its pre-release position. Although any type of latching mechanism  70  so capable is acceptable, the presently preferred latching mechanism uses a float  72 , which can indicate the level or flow of the fluid. Although the float  72  is positioned within the door  22 , the invention can be configured so that fluid contacts the float  72 . Moreover, the invention is not limited to two floats as illustrated in FIG. 7, as the invention can contain any number of floats  72 . Once the float  72  is lifted by the height or flow of the fluid to a preset level, the door  22  can be released. Many types of devices are capable of sensing the float  72  at a preset level and capable of subsequently releasing the door  22 , and the invention is not limited as to a particular type of sensing and releasing device. 
     In one arrangement, the sensing and releasing device can be a pin  74  extending from the float  72 . Referring to FIGS. 11 a  and  11   b , the pin  74  can be adapted to be inserted into an open slot  78  in the frame  10 . As illustrated in FIG. 11 a , when the pin  74  is positioned within the open slot  78 , the door  22  can be prevented from swinging in either direction. The position of the opening of the open slot  78  determines the level of fluid at which the door  22  can open. Once the float  72  is lifted by fluid such that the pin  74  exits the opening of the open slot  78 , the pin  74  is not constrained by the open slot  78  and can rotate in the direction of the current of the fluid, as illustrated in FIG. 11 b.    
     The frame  10  also preferably includes a channel  80  which can allow the pin  74  to pass through the frame  10  as the door  22  rotates. The width of the channel  80  is preferably at least as great as the range of movement of the pin  74  in the door  22 . The range of movement of the pin  74  is preferably constrained by a pin slot  82  in the door  22  through which the pin  74  extends. 
     Use of the float  72 , pin  74  and open slot  78  also acts as a resetting mechanism. When the fluid level drops sufficiently, the pin  74  can be lower than the opening in the open slot  78  if the door  22  is at a substantially perpendicular position relative to ground. The door  22 , however, may not be perpendicular until the weight of the door  22  overcomes the force of the current of fluid pushing against the door  22 . To assist the resetting process, one or more guides  84  can be disposed on the frame  10 . The guides  84  can be used to position the pin  74  in the open slot  78 . The guides  84  can be used when the door  22  returns to a substantially perpendicular position, which occurs when the level of fluid is lower than the opening in the open slot  78 . The guides  84 , which can be disposed on both sides of the open slot  78 , can be angled upward to position the pin  74  upward as the door  22  rotates to a substantially perpendicular position. Once the door  22  reaches this position, the pin  74  can be at the level of the opening of the open slot  78 , such that when the pin  74  is positioned over the opening, the pin  74  can fall into the open slot  78  thereby resetting the latching mechanism  70 . 
     The latching mechanism  70  can be any structure suitable for sensing the level of fluid passing through the vent  8  and for releasing the door  22  at a preset fluid level. Additional structures, such as paddles, levers, tabs, and paddle wheels, can be used independently, or in addition to the above-described latching mechanism  70  to sense the fluid level and to release the door  22 . 
     Fluids flowing through the vent  8  may rise and recede very slowly, or in the case of a storm surge, can rush in very quickly. The latching mechanism  70  can be configured to utilize the force of flowing fluids to release the door  22 . Referring to FIGS. 12 a - 12   d , the latching mechanism  70  can include an actuating structure  160 , which can translate the force of flowing fluids into a lifting force to release and open the door  22 . The actuating structure  160  can include a float  172 . The float  172  can be configured to have a paddle-like configuration so that it can be displaced along a predetermined trajectory by the force of flowing fluids, such as water. 
     The float  172  preferably has a bottom surface  165  contacting a float pin  174 . The float  172  can have any suitable configuration, however, the float  172  is preferably configured to translate the force of fluids flowing through the vent  8  into an actuating force to release the float pin  174  from the open slot  78  thereby causing the door  22  to open. As shown in FIG. 13, the door  22  can include one or more apertures  130  to channel flowing fluids directly to the float  172 . Turning back to FIG. 12 b , in one arrangement, the float  172  can have a paddle-like configuration with a front surface  161  and a rear surface  163 . The front and rear surfaces  161 ,  163  can be oriented substantially perpendicular to the direction of inward and outward fluid flow within the vent  8 . In the illustrated embodiment, the front and rear surfaces  161 ,  163  flare outwardly to provide a narrower upper portion  167  and a wider bottom surface  165 ; however, the invention is not limited in this regard, as the float  172  can be any configuration suitable for transforming forces from flowing fluids into rotation by the door  22 . The front and rear surfaces  161 ,  163  can intersect with the bottom surface  165  to define lower edges  151 ,  153 . The lower edges  151 ,  153  can be any suitable shape in order to serve as rotational points to allow the float  172  to pivot backwards or forwards on a surface. For example, the lower edges  151 ,  153  can be rounded, as shown in FIG. 12 b . In addition, the lower edges  151 ,  153  can also be sharp corners. 
     FIGS. 14 a - 14   f  illustrate the float  172  within the door  22 . FIG. 14 a  shows the position of the float  172  when the fluid level within the vent  8  is not sufficient to displace the float  172 . The door  22  can be in a vertical, closed position, and the float pin  174  can be seated in the open slot  78 . When the float  172  is not displaced by the fluid within the vent  8 , the rounded edges  151 , 153  can rest on the base  29  of the door frame  28 . The open slot  78  can be configured to functionally engage the configuration of the float  172  to facilitate the opening of the door  22  when the fluid rises to a sufficient level. The rounded edges  151 ,  153  can allow the float  172  to rotate about oppositely disposed fulcrum points  181 , 182  on the base  29 . 
     FIGS. 14 b - 14   f  illustrate the action of flowing fluid on the float  172 . As seen in FIG. 14 b , flowing fluid can enter the door  22  through the apertures  130  (FIG. 13) in the door frame  28 . The force of the flowing fluid can tilt the float  172  and can cause the float  172  to pivot on the rounded edge  153  at the fulcrum point  182 . This motion can lift the float pin  174  out of the open slot  78 , which can release the door  22  thus permitting the door  22  to swing open with the flow of the fluid. The pin slot  82  in the door frame  28  can constrain the upward movement of the float  172 . In FIGS. 14 c  and  14   d , the force of the flowing fluid can push the rear surface  163  of the float  172  against the door  22  thereby forcing the door  22  into the open position. As shown in FIG. 14 e , it can be seen that the channel  80  can allow the passage of the pin  174  through the frame  10 . As seen in FIG. 14 f , once the door has rotated into the fully open position, the force of the current and the buoyancy of the float  172  can maintain the door  22  in the open position. The float  172 , door frame  28  and channel  80  are preferably symmetrically constructed to allow the door  22  to be opened by the inflow and outflow of fluid into the vent  8 . 
     After the fluid level has dropped, the above-described arrangement of the float  172 , the float pin  174 , door frame  28  and the open slot  78  can function as a resetting mechanism. That is, when the fluid level has sufficiently receded, the float  172  can tilt on the fulcrum point  182  back to its original position, and the float pin  174  can rotate back into the open slot  78  to latch the door  22 . 
     In the event that the incoming fluid rises slowly and does not have sufficient current flow to push the float  172 , the buoyancy of the float  172  can lift the float pin  174  out of the open slot  78 , and the door  22  can be released in the manner described in the previous embodiment. The door  22  can thus be released by the buoyancy of float  172 , by the force of flowing fluid pushing on the float  172 , or by a combination of these two methods working in cooperation to release the door  22 . 
     FIGS. 15 and 16 illustrate one way to insert the door  22  into the frame  10 . As shown in FIG. 15, the door  22  can be held substantially perpendicular to the frame  10  and can then be inserted into the frame  10  by positioning the door pins  86  on the door  22  into the opening of the door slot  88  in the frame  10 . The opening of the door slot  88  can be positioned slightly higher than the final vertical position of the door pins  86  so that the door  22  can be rotated substantially perpendicular to the frame  10 . Once each pin  86  is in its respective door slot  88 , the door pin  86  can be constrained from movement in any direction except along the length of the door slot  88 . The bottom of the door slot  88  can define the final horizontal and vertical position of the door pins  86 . 
     As shown in FIG. 15, the configuration of the door slot  88  can limit the translational movement of the door pin  86 , even if the door pin  86  is moved slightly upward. Also, this feature can prevent the door  22  from being removed from the frame  10  when the door  22  is in a closed positioned. Thus, to remove the door  22 , the door  22  must be positioned at an angle so that the door pins  86  can be lifted upward in the door slot  88  and then towards the opening of the door slot  88 . A portion of the door slot  88  can continue vertically past the opening of the door slot  88  which can reduce the possibility of unauthorized or accidental removal of the door  22 . In addition, a retainer (not pictured) can be added to the door slot  88 , which can be removed only with a special tool. As a result, the retainer can prevent unauthorized entry. 
     FIGS. 17 a-d  depict another embodiment of vent  8 . Specifically, FIG. 17 a  is a cross-sectional side view of a vent  8  having a retention mechanism for preventing the door from opening while frame  10  is rotated from a generally vertical position to a generally horizontal position. In one embodiment, the retention mechanism is a bracket  200  for preventing flood door  22  from opening when the structure to which vent  8  is attached is moved or rotated from a generally vertical position, referred to as a resting position, to a generally horizontal position. For instance, if vent  8  is installed in a conventional overhead garage door, as shown in FIG. 17 a , bracket  200  prevents flood door  22  from opening while the garage door is being moved into a generally horizontal position. Vent  8  having bracket  200  is useful in any door or wall that that undergoes a change in position that would cause flood door  22  to open as a result of this change in orientation. 
     Bracket  200  may be composed of numerous configurations. For instance, as shown in FIGS. 17 a-d , bracket  200  is generally L-shaped and composed of a stop surface  202  coupled to a rotatable arm  204 , which may be rotatably attached to frame  10  or flood door  22 . Rotatable arm  204  is generally parallel to frame  10 . Stop surface  202  is generally flat and may include stop edges  206  and  208  for restricting movement of float  72 . Stop edges  206  and  208  are projections that extend generally orthogonally from stop surface  202 . Stop surface  202  is coupled to an end of rotatable arm  204  and is generally perpendicular to arm  204 . However, stop surface  202  may be coupled to arm  204  in other configurations that allow bracket  200  to function as described below. Bracket  200  is not limited to the exemplary embodiment shown in FIGS. 17 a-d . Rather, bracket  200  may be configured from any shaped device that prevents flood door  22  from opening by preventing a locking mechanism from releasing flood door  22 . In this embodiment, bracket  200  prevents float pin  74  from leaving open slot  78 . 
     Bracket  200 , as shown in FIGS. 17 b-d , prohibits flood door  22  from opening by preventing float pin  74  from being released from open slot  78 . As the structure in which flood door  22  is installed, which will be referred to hereinafter as a garage door, is rotated away from a vertical position, as shown in FIG. 17 b , bracket  200  pivots about pivot  210  and remains in a generally vertical position. However, float  72  does not remain in a generally vertical position, but initially begins to rotate with the garage door. As the garage door continues to rotate towards a horizontal position, float  72  does not continue to rotate with frame  10 , as shown in FIG. 17 d . Rather, float  72  moves from initial position  212 , shown in dashed lines, to a second position  214  in which float  72  contacts stop edge  206 . Stop edge  208  then contacts an interior wall  211  of flood door  22  and prevents float  72  from additional rotation. As the garage door continues to rotate, flood door  22  is prevented from opening. Therefore, bracket  200  enables an overhead garage door containing flood door  22  to be rotated into a generally horizontal position while preventing flood door  22  from opening. 
     In another embodiment, bracket  200  may be configured to prevent flood door  22  from opening by contacting float pin  74  directly, rather than by contacting float  72  as described above. In this embodiment, bracket  200  may have the same or different configuration than shown in FIGS. 17 a-d . As shown in FIG. 18, bracket  200  may be rotatably coupled to frame  10  and positioned proximate to float pin  74 . Bracket  200  is configured and positioned so that float pin  74  can travel a sufficient distance to allow flood door  22  to open while frame  10  is generally vertical; yet, prohibit float pin  74  from be released from open slot  78  while frame  10  is rotated toward a horizontal position. 
     FIGS. 19 a-f  depict a fluid, such as flood water, opening flood door  22  having a bracket  200 . Bracket  200  is positioned on frame  10  relative to float  72  so that float  72  is capable of moving a sufficient amount to release floating pin  74  from open slot  78 . As the level of flood water rises, float  72  floats upward, as shown in FIG. 19 b , or rises and tilts to one side, as shown in FIG. 19 c , which may be caused by the flow of flow water. This movement of float  72  causes floating pin  74  to be removed from open slot  78 . The force of the flood water then causes flood door  22  to open, as shown in FIG. 19 d . In addition, float  72  is buoyant, which causes flood door  22  to open as float  72  rests on the surface of the water. Flood door opens partially, as shown in FIG. 19 e , when the level of flood waters is within the opening regulated by flood door  22 . Furthermore, float  72  partially fills with water after at least some air contained within float  72  has escaped. As the level of flood waters surpasses the opening regulated by flood door  22 , as shown in FIG. 19 f , flood door  22  rotates into and remains in a generally horizontal position. In addition, float  72  becomes completely filled with flood water. 
     Flood door  22  may include louvers, as described above and shown in FIGS. 7,  10  and  13 , or may include a solid outer surface, as shown in FIG.  20 . In addition, flood door  22 , as shown in FIG. 23, may or may not include insulation  220 . A solid outer surface is desirable in flood prone areas where ventilation is not required or desired, such as, air conditioned first floor entries and garages. 
     As shown in FIGS. 21 and 22, vents  8  may be installed in a stacked, modular formation in a wall forming a portion of a house or other structure or in an overhead garage door. Such a formation may be desirable in flood prone areas where the number of vents required for proper ventilation would make the foundation structurally unsound if the vents were placed side by side. This formation is also desirable when a foundation is not formed from concrete block but formed from poured concrete where it is more desirable to make holes of larger size but fewer in number than numerous openings having small sizes. In this formation, each vent  8  may or may not act independently from each other. 
     It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application. The invention can take other specific forms without departing from the spirit or essential attributes thereof for an indication of the scope of the invention.

Summary:
A flood gate is provided that includes a frame defining a fluid passageway, a door pivotally mounted in the frame for movement between a plurality of open positions to permit flow of fluid therethrough, and at least one latching mechanism for holding the door in the closed position. The latching mechanism can release the door when the fluid force meets a preset level, by floatation, or by flow actuation. In addition, the latching mechanism can reset the door to the closed position when the fluid force acting on the door drops below the preset level. The door can include a ventilation opening, an automatic louver assembly for controlling air flow through the ventilation opening and a screen covering the ventilation opening. The flood gate may include a retention mechanism for preventing the door from opening when the structure in which the flood gate is mounted, such as an overhead garage door is rotated or otherwise moved.