Abstract: An access door assembly is for a floor structure. The access door assembly includes a door frame coupled to the floor structure and defining an opening aligned with a staircase, and an access door within the opening and having first and second longitudinal sides. The first longitudinal side defines a first opposing bevelled surface, and the floor structure adjacent the opening defines a second opposing bevelled surface. The access door assembly also includes an arm coupled to the access door and configured to pivot the access door between an open state and a closed state. The first and second opposing bevelled surfaces are aligned and abutting in the closed state, and are in spaced apart relation in the open state.

Abstract: A combined seat/stair arrangement for a multi-deck vehicle, in particular a multi-deck aircraft or spacecraft, include a foldable passenger seat; a stair which is designed to connect an upper deck to a lower deck via a stair hatch and at least one floor flap which movable between a use position of the stair with the stair hatch open and a use position of the foldable passenger seat with the stair hatch closed, wherein, in the use position of the foldable passenger seat, the at least one floor flap closes at least a partial region of the stair hatch, and wherein the floor flap is designed with a seat attachment, to which the foldable passenger seat is attached.

Abstract: An air moving system includes an air moving device including a housing member, a rotary fan assembly, and an opening for connection with an airflow duct, the housing including a plurality of air intake vents. A first volume of air can enter the housing through the opening and a second volume of air can enter the housing through the plurality of intake vents. The rotary fan assembly directs the first and second volumes of air.

Abstract: The present invention relates to a structure for supporting an information or surveillance device above a road. The structure includes: at least one post extending upwards from the ground to an elevated position, at least one overhead beam which is supported by said post, the overhead beam extending over a horizontal distance above the road, at least one information or surveillance device being connected to said overhead beam and being positioned above the road, a catwalk extending along the overhead beam, wherein said catwalk comprises a guard rail assembly which is movable between: an operating position in which the guard rail assembly extends upwardly from a floor of the catwalk and protects personnel from falling from the catwalk, and a retracted, non-operating position in which the guard rail assembly is concealed behind the overhead beam when viewed from a direction of approaching traffic on the road.

Abstract: Elevated work platforms, as well as associated methods, are provided. In one particular embodiment, an elevated platform apparatus is provided comprising a first rail assembly having a pair of rails coupled with a plurality of rungs, a second rail assembly hingedly coupled with the first rail assembly, a platform configured to rest upon a portion of the first rail assembly and the second rails assembly and a cage associated with the platform. The cage may include at least one bar and at least one gate, the at least one gate being configured to swing in a first direction upon a user stepping on to the platform from the first rail assembly, and then swing back to a closed position after the user is standing on the platform. The at least one gate is also limited from being displaced in a second direction, opposite the first direction, beyond the closed position.

Abstract: A maintenance step for a helicopter, comprising: a casing that is adapted for integration into a lateral shell of a fuselage of a helicopter, and a step member that is pivotally mounted to the casing, wherein a stirrup unit is pivotally mounted to the step member, the stirrup unit comprising at least a first and a second section, the second section being telescopically mounted to the first section.

Abstract: An aircraft comprising a rear opening and a rear door to close such rear opening, wherein the rear door is attached to the fuselage of the aircraft by means of an arrangement having two links due to which the rear door can be displaced longitudinally and in elevation up to a position at the interior of the fuselage.

Abstract: An aircraft comprising an opening for accessing a compartment and a ladder. The aircraft comprises at least one support. The ladder comprises at least one fastener element connected to a support by a removable connection comprising a pivot axis.

Abstract: An aeroplane includes an escape opening passing through an external skin and an internal bulkhead. The escape opening is closed off by an external escape hatch having an external opening controller. The aeroplane further includes an internal escape hatch that closes off said escape opening flush with the internal bulkhead, and kept closed by at least one catch movable between a locked state and unlocked state, a first opening controller that controls the passage from the locked state to the unlocked state of the catch being accessible from inside the aeroplane, and a second opening controller that controls the passage from the locked state to the unlocked state of the catch being positioned such that the actuation of the external opening controller of the external escape hatch or the passage of the external escape hatch from the closed position to the open position causes the second opening controller to be actuated.

Abstract: An aeroplane includes an external skin and an internal bulkhead delimiting a cabin, and an escape opening passing through the external skin and the internal bulkhead. The escape opening is closed off by an external escape hatch disposed flush with the external skin. The aeroplane also includes an internal escape hatch that closes off the escape opening disposed flush with the internal bulkhead, and pressure regulating means capable of automatically triggering an opening of the internal escape hatch or a part of the internal escape hatch when a pressure differential on both sides of the internal escape hatch exceeds a determined value.

Abstract: An airplane flight deck which includes an escape opening closed off by an emergency door and an emergency hatch. The emergency hatch comprises a sheeting and a locking/unlocking mechanism configured to take up a locked state in which the sheeting closes off the escape opening and an unlocked state in which the sheeting frees the escape opening.

Abstract: An aircraft boarding handrail that is affixable to an aircraft fuselage having an entry and exit staircase assembly formed in a cabin door of the aircraft fuselage is disclosed. The aircraft boarding handrail includes a rail member and a mounting structure coupled to the rail member and configured to secure the rail member to the aircraft fuselage. The mounting structure includes a guide pin that interfits with a guide pin slot of a doorframe of the cabin door, a mounting bracket having a notch formed therein constructed to interfit with a staircase support strut mount of the entry and exit staircase assembly, a latch arm coupled to the mounting bracket so as to be rotatable between an open position and a closed position to selectively provide access to and close off the notch, and a quick release pin to lock the latch arm in place when in the closed position.

Abstract: A foldable ladder for providing access to an opening including: a first motorized drive mechanism for moving a cover for the opening between a closed position and an open position; a second motorized drive mechanism coupled to a plurality of foldable ladder portions for moving the ladder portions between a folded configuration and an unfolded configuration; such that, in moving the cover between the closed and an open position, the first motorized drive mechanism triggers the second motorized drive mechanism to move the ladder portions between the folded configuration and unfolded configuration.

Abstract: The present disclosure provides a system of light weight folding stairs, especially lightweight wooden stairs, designed for installation in the ceiling of a building. For example, the light weight ladder-type stair system may be opened downwards and unfolded towards inside the room located under this ceiling. At least one ladder-type stair section is connected to a flap that fits within a frame in an opening in the ceiling, wherein the flap hinges open to access the folded stair sections. The ladder-type stair section is connected to the flap by a hook-type holder that allows installing the frame in a ceiling opening without the flap, which can be easily and quickly attached during final stage of assembly.

Abstract: An attic ladder system includes an upper portion that can be extended above the attic floor and a lower portion that can be extended into a room below the attic. The upper portion can extend automatically into the attic upon extension of the lower portion, or may be operated independently of the lower section. Ladder extension can be telescopic or by unfolding of sections. Retraction of either or both ladder portions may include a pivoting capability to reduce vertical height when stored. A gap can be provided between lowest the rungs to avoid danger to a user's hands. Embodiments can be used to access the top of a vehicle roof from within the vehicle. Embodiments can support a user weighing up to 300 pounds. A gas spring can assist in lifting and stowing the lower portion. Pivot latches can secure the ladder in its stowed and deployed configurations.

Abstract: A deck deployment system is adapted to facilitate transfer of personnel between spaced elevations. The deck deployment system includes a deck defining a substantially flat and continuous deck surface for supporting personnel. A convertible stairway is hinged to the deck and adapted for movement between a stowed condition and a deployed condition. The convertible stairway includes an adjustable frame assembly and a series of articulating horizontally-disposed foot treads carried by the frame assembly. The foot treads remain substantially horizontal upon movement of the stairway between the stowed condition and the deployed condition. When the stairway is in the stowed condition, the foot treads integrate with the deck to form a substantially flat and continuous portion of the deck surface. When the stairway is in the deployed condition, the foot treads cooperate to form steps extending from the deck to an elevation spaced from the deck surface.

Abstract: A remote controlled overhead ladder system including a ladder structure having at least a first section and a second section. The ladder structure can be mounted to a support structure located above an opening of the overhead surface, and can include a remote controlled lifting cable connected to the first and second sections such that upon receipt of a remote control signal, the lifting cable pivots the second section toward a front surface of the first section until the second section is oriented adjacent to the front surface of the first section, at which time the lifting cable pivots the first section and the adjacent second section as a group toward the overhead surface until the ladder sections are contained above the overhead surface.

Abstract: An access ladder includes a plurality of sections connected together to telescope between an extended position and a retracted position that has an increasing reactive force to counterbalance the weight of the sections as they extend. A method for accessing a room with a ladder connected to a ceiling including the steps of moving the ladder to a fully extended position subject to an increasingly active force to counterbalance the weight of the ladder as it extends. There is the step of retracting the ladder into a retracted position in the ceiling.

Abstract: A folding ladder assembly having a door, a frame, and a strut connecting the door and frame. The strut comprises a first end and a second end opposite the first end. The first end of the strut is attached to the door via a strut stop bracket. The other end of the strut is attached to a stationary mounting plate, which is attached to the ladder opening frame. The strut is attached to the strut bracket via a strut standoff using an E-clip retaining ring. Optionally, the strut standoffs are riveted to the strut stop bracket and the stationary mounting plate. The strut stop bracket is optionally formed having a double bend to form two substantially parallel portions connected by a third non-parallel portion.

Abstract: Novel stowed staircases for attics and the like that exhibit highly effective fireproof properties are provided. The combination of sheet metal well sides with ceramic paper covering, a combination thermal board and cement-like construction door, coupled with a sealed gasket at the interface of the stair bottom with the ceiling provide the necessary long-term fireproof capabilities as well as facilitation in installation as a sufficiently lightweight article. In such a manner, the inventive stairway construction may be easily incorporated within a residential or other type unit to aid in the simultaneous accessibility to an attic (or like location) and ability to prevent fire from easily spreading into or out of said attic via the stair assembly itself.

Abstract: An access ladder for an access hole in a building includes a plurality of sections which telescope relative to each other between an extended position, where the sections define a plane and a user can climb the sections, and a retracted position where the sections are folded on each other. Several of the sections have a least one step which preferably moves between an unfolded position where the user can stand on the step when the sections are in the extended position, and a folded position when the sections are in the retracted position. Each section slides relative to another section of the plurality of sections which it is in contact in order for the sections to telescope. A method for using an access ladder attached to an end of an access hole of a building.

Abstract: An access panel is shown in the present invention to provide easy and safe access to an attic space or elevated structure. The access panel is fully automatic. During opening, the access panel uses an energizing motor to control the gravitational forces for opening a cover and deploying ladder sections. During closing, the access panel is energized to retract the ladder sections and close the access panel. The motor is energized to close the access panel until a stow latch engages to stow the access panel during non-use. A safety switch is mounted inside the attic space to allow a user to open the panel and extend the ladder should the user be trapped in the attic space.

Abstract: An access ladder for accessing a ceiling from a floor. The ladder comprises a plurality of sections which telescope open and closed, and from a bottom section each section telescopes open to positively lock to the section below it with plungers that lock and unlock each section in sequence as the sections open and close, respectively. A method for using an access ladder for accessing a ceiling from a floor.

Abstract: An access ladder includes a plurality of sections connected together to telescope between an extended position and a retracted position that has an increasing reactive force to counterbalance the weight of the sections as they extend. A method for accessing a room with a ladder connected to a ceiling including the steps of moving the ladder to a fully extended position subject to an increasingly active force to counterbalance the weight of the ladder as it extends. There is the step of retracting the ladder into a retracted position in the ceiling.

Abstract: An access panel is shown in the present invention to provide easy and safe access to an attic space or elevated structure. The access panel is fully automatic. During opening, the access panel only uses gravitational forces for opening a cover. Only during closing is the access panel motorized. The gravitational forces are used to both open the cover and extend the ladder sections, while the motor is only used to retract the latter sections and close the cover. A stow latch keeps the cover closed during non-use. A safety switch keeps the access panel from accidentally opening and the ladder sections from lowering if the stow latch is released. A mechanical lock keeps the cover open when the ladder sections have been lowered.

Abstract: An access ladder for an access hole in a building includes a plurality of sections which telescope relative to each other between an extended position, where the sections define a plane and a user can climb the sections, and a retracted position where the sections are folded on each other. Several of the sections have a least one step which preferably moves between an unfolded position where the user can stand on the step when the sections are in the extended position, and a folded position when the sections are in the retracted position. Each section slides relative to another section of the plurality of sections which it is in contact in order for the sections to telescope. A method for using an access ladder attached to an end of an access hole of a building.

Abstract: An access ladder for accessing a ceiling from a floor. The ladder comprises a plurality of sections which telescope open and closed, and from a bottom section each section telescopes open to positively lock to the section below it with plungers that lock and unlock each section in sequence as the sections open and close, respectively.

Abstract: A folding ladder assembly having a door, a frame, and a strut connecting the door and frame. The strut comprises a first end and a second end opposite the first end. The first end of the strut is attached to the door via a strut stop bracket. The other end of the strut is attached to a stationary mounting plate, which is attached to the ladder opening frame. The strut is attached to the strut bracket via a strut standoff using an E-clip retaining ring. Optionally, the strut standoffs are riveted to the strut stop bracket and the stationary mounting plate. The strut stop bracket is optionally formed having a double bend to form two substantially parallel portions connected by a third non-parallel portion.

Abstract: A sectional overhead ladder with a fold assist feature for controlling the extension of the sectional overhead ladder. The fold assist feature of the sectional overhead ladder limits the possibility of free extension of the extendable overhead ladder by preventing gravitational forces from causing the ladder sections to fall into their extended configuration. The sectional overhead ladder includes generally a stair structure and an extendable dampening system. The extendable dampening system is comprised of a dampener and, optionally, a housing. The stair structure includes a first section and a second section. The dampening system is attached to the first and second sections of the stair structure such that the dampener limits the free extension of the stair structure and assists with the collapse of the stair structure.

Abstract: A ceiling mounted fan ventilation device moves a fresh inflow of air from within a room such as a garage to said attic thereof in an effective manner in order to mitigate the climatic effects on the room due to adverse ambient conditions. The device is not only capable of moderating the temperature of the room, but also augments the existing ventilation system for the attic enclosure. The device may utilize the existing hole of an attic access means such as a disappearing stairway or scuttle hole thus negating the need for extensive modifications to an existing ceiling structure. Alternatively, a method is disclosed herein whereby the fan ventilation device may be mounted directly to the ceiling portion of the room. The device may be implemented in any type of room wherein it is desirous to maintain a fresh flow of air therethrough.

Abstract: A pre-compressed gas strut assembly and method of installing it for use as the extension and retraction part of a folding ladder configured for installation in an opening, such as an opening in a ceiling of a house or other building. The pre-compressed gas strut has holding members attached to end caps having radial protrusions arranged on opposite ends of the gas strut that maintain the gas strut in a compressed position during installation of the attic ladder assembly.

Abstract: A platform lift system includes a mounting frame that is fixedly engaged into a scuttle hole formed in a horizontal supporting surface (i.e., attic floor or room ceiling) and a foldable ladder that is supported by the frame. A separate trolley carries a lift platform that may be selectively raised or lowered in order to transport objects to/from the attic space. The trolley is moveable horizontally along a track that may be provided on a floor of the attic space. At a first end of travel of the trolley along the track, the trolley is disposed laterally alongside and vertically offset from the mounting frame such that the space above the mounting frame is unimpeded to permit a user to access the attic space using the deployed ladder. At a second end of travel of the trolley along the track, the trolley is aligned vertically with the mounting frame to permit use of the lift platform.

Abstract: An access ladder includes a plurality of sections connected together to telescope between an extended position and a retracted position that has an increasing reactive force to counterbalance the weight of the sections as they extend. A method for accessing a room with a ladder connected to a ceiling including the steps of moving the ladder to a fully extended position subject to an increasingly active force to counterbalance the weight of the ladder as it extends. There is the step of retracting the ladder into a retracted position in the ceiling.

Abstract: A support frame for a folding ladder, a folding ladder positioning system, and a method for installing a folding ladder, are disclosed and pertain to folding ladders disposable within an opening, such as openings in a ceiling of a house, to provide temporary access between one floor or space and another floor or space. In one aspect, a support frame includes a plurality of separable support frame plates collectively configured to circumscribe the opening and a plurality of connection sites are disposed at opposing ends of each of the plurality of separable support frame plates to facilitate connection of each support frame plate to adjacent support frame plates. The connection sites include, for example, mating locking connectors or a plurality of matching through-holes, which permit insertion of a fastening means therethrough.

Abstract: A novel escape system comprised of a plurality of escape devices each which resemble a window shutter, are mounted on the outside of a building, adjacent the windows vertically above the next lower escape device. Since these take up no space inside of the building, and are aesthetically pleasing, they are less likely to be removed or overridden making them functional a greater percentage of the time. Each is comprised of a frame to hold a plurality of slats connected to a collapsible vertical connecting means a predetermined distance apart from the others. In its storage position, the slats are held in the frame in an angled position resembling louvers. When in the operational position, the slats are allowed to drop down out of the frame and extend down to the next lower escape device with the slats acting as steps of a ladder. The bottommost end of the escape device connects to the top of the next lower escape device to create a continuous escape system allowing egress from any floor to the ground.

Abstract: A platform lift system includes a mounting frame that is fixedly engaged into a scuttle hole formed in a horizontal supporting surface (i.e., attic floor or room ceiling) and a foldable ladder that is supported by the frame. A separate trolley carries a lift platform that may be selectively raised or lowered in order to transport objects to/from the attic space. The trolley is moveable horizontally along a track that may be provided on a floor of the attic space. At a first end of travel of the trolley along the track, the trolley is disposed laterally alongside and vertically offset from the mounting frame such that the space above the mounting frame is unimpeded to permit a user to access the attic space using the deployed ladder. At a second end of travel of the trolley along the track, the trolley is aligned vertically with the mounting frame to permit use of the lift platform.

Abstract: A folding ladder is configured for installation in an opening to provide access between one floor or space and another floor or space. The folding ladder includes, in one aspect, an upper ladder section having a left ladder rail and a right ladder rail, a lower ladder section having a left ladder rail and a right ladder rail, a hinge rotatably connecting the upper ladder section ladder rails to the lower ladder section ladder rails, and a plurality of steps rotatably disposed between the upper and lower ladder rails. The plurality of steps are configured for rotation between a retracted position and a deployed position. At least one step disposed between the upper ladder rails and at least one step disposed between the lower ladder rails are linked by at least one linkage member so that each of the noted steps rotates between a retracted position and a deployed position upon rotational movement of the upper ladder section relative to the lower ladder section between a closed position and an open position.

Abstract: An overhead area access staircase system (10) for an aircraft (12) includes an aircraft overhead module (20) and multiple stair segments (40). The stair segments (40) are actuated relative to each other when deployed and are configured to be in proximity with the overhead module (20). The stair segments (40) are in contact with the overhead module (20) when deployed. The stair segments (40) include step elements (42) and support members (44) coupled thereto.

Abstract: A thermal insulating cover is presented. The cover includes a top, a plurality of sides extending from the top and a wide base perimeter extending from the plurality of sides. The device may be formed as a unitary piece, or may be provided in two or more sections which are easily assembled together. A piece of foam, acting as a gasket may be affixed to the base perimeter.

Abstract: A platform lift system includes a mounting frame that is fixedly engaged into a scuttle hole formed in a horizontal supporting surface (i.e., attic floor or room ceiling) and a foldable ladder that is supported by the frame. A separate trolley carries a lift platform that may be selectively raised or lowered in order to transport objects to/from the attic space. The trolley is moveable horizontally along a track that may be provided on a floor of the attic space. At a first end of travel of the trolley along the track, the trolley is disposed laterally alongside and vertically offset from the mounting frame such that the space above the mounting frame is unimpeded to permit a user to access the attic space using the deployed ladder. At a second end of travel of the trolley along the track, the trolley is aligned vertically with the mounting frame to permit use of the lift platform.

Abstract: A ladder apparatus for providing access to an area over an elevated structure, the ladder apparatus including a housing secured to the elevated structure wherein the housing includes a housing mechanism having a central opening, a ladder pivotally mounted to the housing mechanism wherein the ladder includes a first ladder section and at least one additional ladder section slidingly mounted to the first ladder section, first motorized deploying mechanism structured to pivotally displace the ladder to and from a stored configuration and a partially deployed configuration, second motorized deploying mechanism structured to linearly displace the at least one additional ladder section to and from a partially deployed configuration and a fully deployed configuration; and control mechanism structured to operatively control the first and second motorized deploying mechanism.

Abstract: An emergency escape system includes an escape apparatus and a door. The escape apparatus is connected to the door. The escape apparatus includes a cord and a release mechanism. The release mechanism is configured to provide a controlled lowering of a person being lowered on the cord.

Abstract: A ladder apparatus for providing access to an area over an elevated structure, the ladder apparatus including a housing secured to the elevated structure; a ladder pivotally mounted to the housing, the ladder means including an upper ladder section and at least one lower ladder section mounted to the upper ladder section; and a motorized deploying mechanism structured to controllably allow the ladder apparatus to be pivotally and gravitationally deployed from a stowed configuration to a partially deployed configuration, controllably allow the at least one lower ladder section to be longitudinally and gravitationally deployed from the partially deployed configuration to a fully deployed configuration, longitudinally retract the at least one lower ladder section from the fully deployed configuration to the partially deployed configuration, and pivotally retract the ladder apparatus from the partially deployed configuration to the stowed configuration.

Abstract: A stair is pivotable from a lowered position allowing a user to climb the stair from a lower level to an upper level, into a stowed position wherein the stair is lifted from the lower level so that the plane of the stair is approaches the ceiling situated between the lower and upper level. The stair, which is preferably not articulated (i.e., the stair does not fold), rotates between the lowered and stowed positions about a pivot fixed in association with the ceiling. A drive cable, which preferably extends from the stair top or from a drive arm extending from the stair top, is anchored to surrounding structure in the upper level. A drive motor drives the drive cable to draw the stair top downwardly, thereby raising the stair bottom about the pivot.

Abstract: A thermal insulating cover is described along with a method of manufacturing a cover for use over a set of attic stairs, when they are retracted into the ceiling. The cover is made of two major protective surfaces, surrounding a insulating material to form a blanket, that is then cut and folded to form a box, that is fastened together to form the cover.

Abstract: A control apparatus for a folding ladder or stairway. The control apparatus comprises a control base attachable to a section of the ladder and a control arm pivotally attached to the control base. The control arm has a distal end which may be gripped by an operator to manipulate the ladder between folded and unfolded positions while the operator is positioned away from the ladder so that unexpected pivotation of ladder sections cannot result in the ladder sections striking the operator. A clamp may be attached to the ladder to retain the distal end of the control arm when not in use. The control arm is telescoping and may be positioned in any of a variety of extended positions. A lock is provided to lock the telescoping control arm at a desired length.

Abstract: A quick release latched security window guard having a framework attached to a building exterior overlying a window is held with a cam latch system including a cam rod extending through the building wall, with an end protruding into a hollow member forming a part of the framework. A sliding latching sleeve is spring urged into a slot in the cam rod end to lock the framework in place. Rotation of a handle on the rod end within the building forces the sleeve back to be cammed out of the slot to release the framework. One or more fixed slotted latching posts may also be mounted to protrude into the hollow member and to be engaged by portions of the sleeve to form additional latching points, all of which are released by the rotation of a single cam rod. The framework may take the form of one or more ladder sections deployed to hang down from the window when the framework is pushed out after being released by the operation of the cam rod.

Abstract: An apparatus having one or two steps at the election of a user. The apparatus is stored under a counter in a space that is normally wasted. When in its single step configuration the apparatus has a generally parallelepiped appearance and includes a transversely disposed front wall, longitudinally extending side walls, a transversely disposed rear wall, and a top wall that provides a first step. A folding line formed in the top wall enables a trailing section of the structure to be rotated until the rear wall lies in a horizontal plane and provides a second step. A transverse rod facilitates rotation of the second step and the transverse rod supports the second step after it has been deployed. The rod has a telescoped construction and permits lowering of the second step when the user exerts an axial force against the rod.

Abstract: A method and apparatus for insulating apertures is disclosed. An insulating dome is placed over these apertures and can be locked into place, thereby providing insulation for the aperture. The apertures that are typically uninsulated are hidden stair openings and whole-house fans, plywood attic access passageways or other openings. The insulating dome can be lifted automatically once the hidden folding stair is opened or the whole-house fan is used.

Abstract: A cover apparatus (10) is provided which is easily and quickly installed, is simple to use, and is cost effective for selective closing of an attic opening (14) and for providing a thermal and dust barrier. The cover apparatus (10) preferably includes structure (12), adapted for placement over an opening (14) defined by peripheral wall or ceiling surfaces (16), and a plurality of snap fasteners (18a, 18b, 18c, 18d) for detachably coupling the structure (12) to the surfaces (16). The structure (12) includes a panel (20) presenting an inboard face (22), continuous, circumscribing sidewalls (24) extending from the inboard face (22) of panel (20), and a continuous, circumscribing flange (32) extending transversely and outwardly from the outer margin (28) of the sidewalls (24). The flange (32) includes an outermost lip (36) configured for firmly engaging the surfaces (16) when the structure (12) is coupled to the surfaces (16).