Abstract: A pit gate includes a gate body which is inserted between a pool portion storing water and a canal portion connected to the pool portion and is configured to change a flow state of the water, and a seal portion (6) which is accommodated in a groove-shaped accommodation recess formed in the gate body and seals between the pool portion and the gate body. The seal portion (6) includes a low-rigidity portion (10) which is relatively easily deformed by a load according to a water pressure from the pool portion side, and a high-rigidity portion (11) which is provided on the pool portion side of the low-rigidity portion and is not easily deformed relatively by the load.

Abstract: An automated water control device comprises a rotatable housing that can be incrementally positioned to control flow of water over an upper or weir edge of the housing. The device is installed at a control point in an impoundment area, such as a settling pond. The housing is selectively rotated to raise and lower the height of the weir edge to a target gate height. Automatic control is provided for operation of the device by a controller communicating with an actuator. A system of the invention includes one or more water control devices and the controller. A method of the invention includes controlling flow of water from an impounded water source by use of the automated water control device. Manual or semi-automated embodiments are also disclosed.

Abstract: A laterally sliding type opening/closing gate of a torsion structure of reasonable cost is implemented. The gate includes: the torsion structure having a closed cross-section consisting of a thin wall installed such that it may cross a sluice and be composed such that its cross-section may make an in-plane rotation around a restriction point on the cross-section and that a torsion moment generated by an applied load and reaction force on the restriction point is transmitted to its terminal due to its torsion rigidity; and a rail that is installed such that it may cross the sluice; and a plurality of axle type supports that has a function of a restriction point and moves along the rail.

Abstract: A monitoring apparatus is provided to monitor an amount of a liquid discharged from a nozzle. The monitoring apparatus includes a discharge case. The discharge case is configured to receive liquid discharged from a nozzle. The discharge case includes a storage space for storing the liquid. A photographing unit photographs the level of the liquid stored in the storage space.

Abstract: A pit gate 15 that is accommodated in a slot 14 and that seals service water retained in a first pit and a second pit in a watertight manner includes a gate main body 21; a sealing member 22 that is provided on a surface opposite to the slot 14 in a gate main body 21 and that seals between the gate main body 21 and the slot 14 in a watertight manner; and an upper pressing clamp 23, an intermediate pressing clamp 24, and a lower pressing clamp 25 that are provided in the gate main body 21 and that moves gate main body 21 toward the sealing member 22 side due to the weight of the gate main body 21 itself.

Abstract: An apparatus for shutting off the flow of water through ductwork is disclosed that is installed in an air conditioning duct in a building and closes the air conditioning duct in the event of the attack of seawater. Two upper and lower hinged door bodies disposed in the inside of the air conditioning duct are supported by a support device in the state in which the inside of the air conditioning duct is open. The opening and closing operations of the upper door body are interlocked with the opening and closing operations of the lower door body by a chain. A water intrusion detection device releases the supporting of the two upper and lower door bodies in the event of the intrusion of water. The two upper and lower door bodies are horizontally moved in the direction of water pressure when the inside of the air conditioning duct is closed.

Abstract: A system for controllably adjusting spent water levels in the tailrace pool area of a hydroelectric power-generating dam installed into a waterway. The system comprises: (a) a controllably adjustable weir device installed into a downstream portion of the waterway adjacent a distal end of the tailrace pool area. The controllably adjustable weir device is configured for controllably impeding the egress of spent water from the tailrace pool area, (b) an apparatus provided with operative components configured for manipulating the controllably adjustable weir device to controllably increase and decrease the impediment therewith of spent water egress from the tailrace pool area. The operative components are serviceable from above the spent water, and (c) a control device configured for communicating and cooperating with the apparatus for manipulating the controllably adjustable weir therewith.

Abstract: A securing and waterproof mechanism of a floodgate apparatus includes a pillar, a water retaining gate, a pair of retaining bases and a securing member. The pillar has a retaining groove for receiving the water retaining gate. The retaining bases are attached to two opposite sides of the pillar. Each retaining base has at least one vertical channel. The securing member has two hook portions at one side. Each hook portion has a horizontal bar and a vertical bar extending upward from a distal end of the horizontal bar. Under this arrangement, the vertical bar of each hook portion is fitted in the vertical channel of the respective retaining base to prevent the securing member from sliding horizontally off the respective retaining base.

Abstract: A system for recirculating lock water includes a sealable storage area located near a lock for receiving water from the lock. The storage area is large enough to house the lock water with excess space between a maximum water level and the ceiling. The system also includes at least one compressor connected to the storage area to create a vacuum to withdraw the water from the lock into the storage area.

Abstract: Some examples provide methods, systems, devices and/or apparatus related to reducing and/or restricting water from entering underground transportation system, and more Specifically, to reducing and/or restricting water from entering underground transportation systems via vents based on the weight of the water, while not restricting ventilation airflow when water is not present. Some example systems for restricting water flow in a surface vent may include a frame that receives water, a door pivotally coupled to the frame(where the door may pivot between a first position and a second position), and a reservoir pivotally coupled to the door. The reservoir may collect the received water and may cause the door to pivot between the first position and the second position based on weight of the collected water.

Abstract: A turbine system that can be releasably anchored in a flow of liquid, like a waterfall, and generate power from the flow includes a runner operable to receive some or all of the flow of liquid and rotate to generate power, a penstock operable to direct some or all of the flow toward the runner, and an intake operable to direct some or all of the flow into the penstock. The runner may be coupled to a generator to generate electric power. The penstock has a length that is adjustable to accommodate changes in the height of the liquid drop or waterfall, which may be desirable if the distance between the top and bottom of the drop fluctuates like an ocean's tide. The turbine system also includes a valve operable to modify the flow of the liquid flowing into the runner, and a control circuit operable to determine an amount of liquid entering the penstock and, in response to the determined amount, move the valve to increase or decrease the flow of liquid into the runner.

Abstract: An opening/closing device 1 according to the present invention includes a gate 10 that receives a flow of a sewage W in an upright state, and can fall toward a downstream side of the flow and a first spring 52a that generates a force for bringing the gate 10 into an upright state, wherein the first spring 52 generates a force insufficient for bringing the gate 10 into the upright state if the gate 10 is in a fallen state, and generates a force sufficient for bringing the gate into the upright state if the gate 10 is tilted by an angle equal to or less than a predetermined angle.

Abstract: A water-gate is intended to withstand pressure exerted by a liquid. The water-gate includes an essentially flat shell plate and a plurality of thin cores extending along the length of the shell plate, the thin cores being substantially parallel to one another. Each core is solidly connected to the shell plate and pierced with multiple disjoint holes. According to the disclosure, the water-gate comprises at least one stiffener formed by assembling multiple elements that are aligned along a longitudinal axis of the stiffener and that each extend between the cores without passing through the cores. Each element may be solidly connected to a face of at least one core around one of the holes.

Abstract: The invention provides an undershot sluice gate (17) to control flow of liquid through an open channel (10). The gate (17) includes a gate leaf (18) adapted to be raised and lowered by a control means (22) to allow flow of liquid along open channel (10). Gate leaf (18) has at least a pair of opposing liquid level sensors (44, 46) on, or in, gate leaf (18) to provide measurement of liquid level upstream and downstream of gate leaf (18). The sensors (44, 46) are located at a predetermined distance from the lowermost edge of gate leaf (18) to allow said measurements without disturbance from the fluid flow profile resulting from movement of liquid beneath the lowermost edge of gate leaf (18).

Abstract: A system for recirculating lock water includes a sealable storage area located near a lock for receiving water from the lock. The storage area is large enough to house the lock water with excess space between a maximum water level and the ceiling. The system also includes at least one compressor connected to the storage area to create a vacuum to withdraw the water from the lock into the storage area.

Abstract: An opening/closing device includes a gate that receives a flow of a sewage, and can fall toward a downstream side of the flow, a fall prevention unit that prevents the gate from falling by supporting the gate, a support release unit that releases the support for the gate by the fall prevention unit, a first float that is arranged on the upstream side of the gate, and is smaller in specific gravity than the sewage, a surfacing prevention unit that prevents the first float from surfacing, a second float that is arranged on the upstream side of the gate, above the first float, and is smaller in specific gravity than the fluid, and a surfacing-prevention release unit that releases, resulting from surfacing of the second float, the prevention of the surfacing of the first float by the surfacing prevention unit. Further, the support release unit is activated resulting from surfacing of the first float.

Abstract: The shore side of a shore line water barrier is protected from flooding caused by storm surge over-topping the barrier. Water overtopping the barrier, such as from wind waves crashing against the barrier, is trapped, impounded and accumulated between a parapet atop the barrier and walls on the sides of a buoyant gate unit taller than the parapet and walls and normally resident below grade on the shore side of the barrier, hinged about an axis generally parallel to the barrier and spaced from the parapet by a distance not less than the height of the gate unit. The accumulated overtopping water is applied to rotationally float the gate unit from the horizontal position initially principally by buoyancy and then principally by hydrostatic pressure to drive the gate unit to an upright position to oppose storm surges having a water level higher than the parapet.

Abstract: A flood flaps vent for sealing a building crawlspace includes: (a) a vent box portion including open opposite front and rear ends on either end of a vent passageway, the vent box including a top box portion with at least one flap slot adjacent a rear end portion of the vent box, and an opposite bottom box portion; (b) at least one flexible flood flap extending across the open rear end portion, with its upper edge seated in the flap slot, other side flap edges of the flood flap being unattached; and (c) a grate portion over the open front end portion of the vent box; the flood flap occluding the rear end portion of the vent box when it is in an at rest, home position. This simplified abstract is not intended to limit, and should not be interpreted as limiting, the scope of the claims.

Abstract: A floodgate is disclosed. The floodgate comprises a panel configured to be movable between an opened position and a closed position wherein in the opened position, the panel forms a barrier against flood water; and at least one gas strut configured to move the panel from the closed position to the opened position.

Abstract: The invention relates to a roadway flood protection and traffic barrier which provides a smooth upper surface for vehicles, pedestrians, etc. and is thin enough to be mounted to the surface of an existing roadway or parking garage ramp, for example. A hinge mechanism is disclosed which facilitates the provision of a smooth roadway surface as well as a tight seal. A locking strut is provided that keeps the gate panels raised even in case of air pressure loss and which is remotely controllable.

Abstract: Provided is a novel flow control system that includes multiple modifier columns for positioning across a waterway. Bottom ends of the columns are attached to a bottom track extension, for example, at the bottom of the waterway. The columns are sufficiently light so that the buoyancy force pushes their top ends towards the surface forming a “curtain-like” structure that provides resistance to the water flow. Spacing between the columns and other characteristics may be used to adjust this resistance. The columns may be repositioned along the track to change the spacing and/or to form an open pass. The columns are sufficiently robust and may swivel with respect to their bottom support such that their upper portions contact passing vessels. The system may be used to control flow through energy extracting devices or be a part of flood control systems.

Abstract: The invention provides an undershot sluice gate (17) to control flow of liquid through an open channel (10). The gate (17) includes a gate leaf (18) adapted to be raised and lowered by a control means (22) to allow flow of liquid along open channel (10). Gate leaf (18) has at least a pair of opposing liquid level sensors (44, 46) on, or in, gate leaf (18) to provide measurement of liquid level upstream and downstream of gate leaf (18). The sensors (44, 46) are located at a predetermined distance from the lowermost edge of gate leaf (18) to allow said measurements without disturbance from the fluid flow profile resulting from movement of liquid beneath the lowermost edge of gate leaf (18).

Abstract: To make it possible to hold a door body in an immobilized state without oscillating when the raising operation has been completed. A raised state holding mechanism of a flap gate for a breakwater provided with a two-folding support rod which immobilizes and supports a door body the front end side of which is supported to freely rise or lower with a rotating shaft as a supporting point, and a stay which supports this and to which is attached a guide roller the movement of which is guided by a guide rail. Between a two-rod double-acting cylinder device and an oil tank there is a raising side oil supply pathway which supplies oil to a raising side oil chamber, a raising side oil discharge pathway which discharges oil from the raising side oil chamber, and a lowering side oil pathway which supplies/discharges oil to a lowering side oil chamber.

Abstract: The invention provides an undershot sluice gate (17) to control flow of liquid through an open channel (10). The gate (17) includes a gate leaf (18) adapted to be raised and lowered by a control means (22) to allow flow of liquid along open channel (10). Gate leaf (18) has at least a pair of opposing liquid level sensors (44, 46) on, or in, gate leaf (18) to provide measurement of liquid level upstream and downstream of gate leaf (18). The sensors (44, 46) are located at a predetermined distance from the lowermost edge of gate leaf (18) to allow said measurements without disturbance from the fluid flow profile resulting from movement of liquid beneath the lowermost edge of gate leaf (18).

Abstract: A synthetic weir board riser system is described that controls the water elevation on the front and rear sides of the structure using synthetic weir boards as the barrier. Weir boards are added and removed from a metallic or composite riser system to control the level of water flowing into a larger body. Synthetic weir boards composed of plastic or composite have an increased life span. Geometrically, the synthetic boards provide a more efficient use of material in terms of weight. A reduced radius per each external corner prevents the increased pressure to the rear of the riser from separating the synthetic boards thereby increasing seepage.

Abstract: An aqueduct assembly is provided as having a front gate assembly and a rear gate assembly. The front gate assembly has a front gate which will open to let water into the aqueduct assembly. When water begins to rise in the aqueduct assembly, a rear gate of the rear gate assembly opens to let water flow out of the aqueduct assembly. A method for diverting water is also provided. A front gate assembly opens for allowing water to flow into the aqueduct assembly. Subsequently, rear gate assembly opens for permitting water to flow out of the aqueduct assembly.

Abstract: A structurally adaptive flood vent device disposed to allow the passage of both air and flood fluid through and existent structure, in order to relieve buildup of excess water around a structure, while concurrently affording protection from intrusion of foreign matter. The instant design features constant aeration properties, in conjunction with automatic operation toward relief upon the onset of external structural flooding. Use of a door assembly which is entirely removed in an automated process upon flooding is featured.

Abstract: Embodiments are described for preventing downward flow of substantial surface water into an underground ventilation duct communicating upwardly to a ground surface opening. The embodiments comprise a support having a top opening and an opening in a lower portion above a floor. The opening in the lower portion is for venting communication with a proximate portion of the ventilation duct. The support supports at least one seat and paired buoyant gate set. The seat is mounted perpendicularly relative to the gate and a portion of a passageway under the seat for fluidly communicating beyond such portion to the top opening of the support and to the proximate portion of the ventilation duct. The buoyant gate is positioned lower than the seat and the passageway, is of sufficient size to block the passageway, and is responsive to water rising in the support by floatingly pivoting upwardly until engaging the seat, thereby blocking the passageway.

Abstract: The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe aeration, hinges, and bladder manufacture technology are disclosed herein.

Abstract: The flood barrier includes a chamber with a first side wall and a second side wall, a water inlet for letting in water, a single support block arranged on the first side wall, and a dam wall up and down movably arranged in the chamber. The dam wall forms a retaining wall for restraining water flow, a forcing element for causing an upward movement of the dam wall, and a blocking element for providing a blockade for limiting the upward movement, the blocking element. The support block has an inclined surface against which the inclined surface of the blocking element acts in a closed state of the flood barrier. Due to the orientation of the angled wall of the support block, the blocking element is forced to move sideward and thereby a lateral force is created forcing the dam wall to one side of the chamber.

Abstract: A flow limiting inlet structure is designed to collect water or other fluids in a pool above grade, and to provide improved capture of sediments and surface pollutants such as oils and greases in the pool, while regulating the flow of water or other fluids during discharge into an outlet pipe. In a conventional storm water detention basin a vertical cylindrical discharge structure can be used to regulate the basin water depth and discharge flow rate of storm water out of the detention basin, in conjunction with the use of a specially designed baffle system that prevents the release of any greases or oils floating on the water surface while capturing any floating trash or debris.

Abstract: Disclosed is an expansion-sealed flood control gate, comprising a water board, a frame structure, two symmetrical constraint tracks, at least one encased expandable sealing tube, and a plurality of adapters. A U-shaped slot is formed between the two symmetrical constraint tracks for plugging in the water board. Each constraint track has a U-shaped expanding compression chamber connecting from one end to the other end to accommodate the tube inside. The adapters are connected with the open ends of the tube and fixed on the constraint tracks at the connected ends. Accordingly, there can be effectively repelled floods that the tube with the characteristics of active filling and uniform packing stress have the higher geometric tolerance, even if the slits between the water board, the constraint tracks and ground emerge the unexpected geometrical change, the encased expandable sealing tubes are ballooned to mend the slits.

Abstract: A system for controllably adjusting spent water levels in the tailrace pool area of a hydroelectric power-generating dam installed into a waterway. The system comprises: (a) a controllably adjustable weir device installed into a downstream portion of the waterway adjacent a distal end of the tailrace pool area. The controllably adjustable weir device is configured for controllably impeding egress of spent water from the tailrace pool area, (b) an apparatus provided with operative components configured for manipulating the controllably adjustable weir device to controllably increase and decrease the impediment therewith of spent water egress from the tailrace pool area. The operative components are serviceable from above the spent water, and (c) a control device configured for communicating and cooperating with the apparatus for manipulating the controllably adjustable weir therewith.

Abstract: A self-adjusting barrier incorporates a series of float units restrained between a primary wall, such as a bulkhead, and a secondary wall, such as sheetpile. The secondary wall may be braced to the primary wall. The float units slidably interconnect along adjacent edges to self-adjust along a perimeter, such as a marina or waterfront lot, based on the height of water within the chamber (stilling basin) provided between the two walls. Mechanisms for deterring vandalism and providing increased environmental integrity are also provided for select embodiments. Methods of employing the barrier are also disclosed.

Abstract: Disclosed is a foundation vent that provides air ventilation and flood relief for an enclosed area. A screen is included to prevent items such as insects, small animals, debris, and organic matter, including buoyant materials due to a flood, from entering the enclosed area. A removable screen and exterior screen stop allow the owner to easily inspect, maintain, clean, and repair the foundation vent. The foundation vent is also designed as a non-engineered, non-mechanical opening, which allows the air and flood water ratings of the foundation vent to be based upon the actual net clear open area. Such design eliminates the need for a vapor barrier and/or specialized structural engineering of the foundation. The dual operation of the foundation vent as a flood grate also allows rising flood water to penetrate and recede from the enclosed area, which equalizes the hydrostatic pressure on either side of the foundation wall.

Abstract: The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe aeration, hinges, and bladder manufacture technology are disclosed herein.

Abstract: The invention is a diversionary device for storm water runoff that will divert water from the center of the street to the sides of the street where filters are in place by others. The diversion device for diverting storm water consists of a length member having a length and a width, the length extending a selected distance, the length having formed a multiplicity of baffles along the selected distance, the width having a selected profile, the profile being selected to divert storm water, the length member having formed on at least one its ends at least one interlocking means.

Abstract: A method and device for measuring flow rate of a liquid through a gate in a channel. The device having a first pressure sensor for measuring the pressure of the liquid at a first position upstream of the gate. A second pressure sensor for measuring the pressure of the liquid at a second position downstream of the gate. An opening sensor for measuring the position of opening of the gate and a processor for calculating the flow rate using an algorithm based on the measurements.

Abstract: In one embodiment of the invention, a filter assembly for filtering a fluid flowing from a first container into a second container comprises a filter panel disposed in a partition between the first and second containers. The filter panel may include a bristle filter and a frame that holds the bristle filter, and the bristle filter may include a plurality of bristles attached at their proximate ends in an adjacent configuration along the length of a base. The filter panel may be disposed such that the upper ends of the bristles are above a top surface of the fluid in the first container and the lower ends of the bristles are below the top surface of the fluid in the first container.

Abstract: The invention relates to improved pneumatically operated spillway gate systems and methods of constructing and operating the same. Methods of installation without the requirement for coffer dams are disclosed.

Abstract: A modular guide frame for use with gates of various thicknesses is assembled from separate side portions. The side portions are provided with hubs, having facets of different widths. The hubs may be coupled with one another to align the facets and provide different gate guide configurations, having various channel widths. An extension plate may be coupled between the side portions to further expand the width of the channel. Elongated sealing members may be secured within the channel to further customize the fit between the guide frame and a gate. The symmetrical nature of the side portions allow them to be manufactured from a single extrusion form, while retaining the ability to be used with one or more differently sized gates.

Abstract: Disclosed is a floodgate opening and closing system using a measurement of a motor revolution count, in that an opening and closing state of a floodgate formed at irrigation facilities for sewage, rainwater, agricultural water, freshwater and so on can be numerically transformed and the transformed data can be transmitted to a data collection apparatus such as a remote control system or transmission system and so forth through a communication network and so on, so that the opening and closing rate of the floodgate can be exactly perceived and controlled in a real-time on the remote place, whereby increasing the efficiency of water management.

Abstract: This invention discloses a simple and convenient method of floods control and with great discharge capacity. This invention is a method of speeding up the river floods water discharge ability into the sea by means of the natural tidal range. This is done by the following technical proposals. To set up the PTCCG between the tidal current limit of the estuary and the coast tangent or narrower part of the estuary; the said PTCCG should be built across the river from the banks theoretically. When there is a danger of flood during the floods seasons, we can close the PTCCG and prevent the tidal current from entering into the inner river. When the tide ebbs, we can re-open the PTCCG and discharge the freshwater withheld into the sea. The PTCCG is normally open when it is not used. This invention is applicable to all tidal estuaries, which are affected by the astronomical tide range.

Abstract: An irrigation gate system installed in a channel (such as a ditch or canal) for controlling the flow of water through the channel maintaining a desired level of water upstream from the irrigation gate system or for controlling water flow downstream from the irrigation gate system. The irrigation gate system includes a gate which is maintained in a closed position for preventing water flow past the gate or alternatively, in one of a plurality of open positions for allowing desired amounts of water in the channel to flow past the gate. The gate is vertically hingedly connected to a pipe shaft supported by a frame installed in the channel. A gate actuator moves the gate between its various positions upon receiving signals from an electronic programmable controller which in turn may receive signals from a variety of sources.

Abstract: The invention relates to improved water control gates and related inflatable actuators, and associated sealing, manufacture and operation apparatus and methods. Advancements in technologies related to air fitting design, inflated bladder stress relief, inflatable bladder strength enhancement, water gate related slide friction mitigation, abutment and other impounded water seals, gate panel fabrication, traffic accommodating water impoundment structures, and water gate panel system operation efficiency, as well as nappe areation, hinges, and bladder manufacture technology are disclosed herein.

Abstract: A method of assembling a lock and dam system is disclosed to minimize the rate of structural fatigue associated with closing of the lock and dam system. The lock and dam system includes one or more gates that may include a plurality of girders, plates and associated support or reinforcing members. The gate has a miter end and a quoin end. On the miter end a miter block, and thrust plate transfer impact forces associated with closing of the gate from the point of impact to the remainder of the gate. The thrust plate is preferably a substantially uniformly thick member that is secured vertically to the gate through a slot cut or formed in the end of the horizontal plate on the miter and quoin end. Preferably, the thrust plate is secured using a fillet weld.

Abstract: Device for retaining water comprising a foundation, a retaining wall movably attached to the foundation and a shore movably, particularly hingingly, attached to the foundation, in which the shore and the retaining wall are movably, particularly hingingly, attached to each other, and in which the retaining wall is provided with at least an internal longitudinal hinge about which the retaining wall can be turned.

Abstract: A flow leveling device for use in a liquid distribution system that can be attached to the end of a conduit The device has an eccentrically placed opening on the face of the device whose vertical position can be varied so as to equalize the flow of liquid dispersed from a central point. The device is secured to the conduit by a double-walled skirt depending from the face of the device. The skirt has a central gap defined by the double walls which securely holds the conduit walls therein.

Abstract: The device is composed of two, horizontally aligned component parts, namely, fixed spinway subtending an angle of 60° and a pivotal wedged-shaped module residing at a specific and constant distance parallel to the spillway face. The wedge-module is designed so that it rotates around a defined arc radius so maintaining both a constant distance between interfaces of the wedged-module and spillway and a constant angle of attack. This device has been demonstrated to accelerate the rate of fluid flow under either low or high head pressures by way of generating a negative pressure (venturi) effect in the device. The nature of the wedge-module is to present a “throat” configuration at the slit opening thereby tending to suck fluid into the device under such negative (venturi) pressures, while maintaining a laminar flow pattern ahead of the wedge-module/spillway arrangement.

Abstract: The present invention provides a movable defensive apparatus in which a dedicated source of power for driving a relatively heavy defensive wall and an installation space are not required, whereby entry of a mob, a runaway vehicle, and the like, can be prevented, the entry of rainwater, and the like, can also be prevented to some extent. The movable defensive apparatus includes a defensive wall (2) disposed in the vicinity of a doorway (O•I) of a site (G), such as a house, and an installation in the vicinity of a doorway (O•I), a window or the like, of a building for preventing rainwater and undesirable entry of objects, such as a mob or a runaway vehicle from entering the site (g) or a building. Also described is a piston cylinder unit (20, 20) which is operated by running water for driving the defensive wall (2) from a machine room (M•R) to a predetermined upper position along a guide device (10, 10).