Abstract: A cab for a power machine having a side window and a rear window each hingedly connected to the same one of a right rear cab frame post and a left rear cab frame post such that when the side window and rear window are both opened by latches to rotate outward relative to the same rear post an airflow path is created diagonally across the operator between a front corner of the cab and an opposite rear corner of the cab.

Abstract: Operating hardware for a window complete comprising an upper platform unit attached to a window frame; a lower platform unit attached to the window frame; a sliding drive mechanism comprising a sliding housing base, a sliding housing top piece, a planetary gear set, and a worm and wheel gear set; and a handle drive mechanism comprising an input bevel gear, a handle drive cap including a first hole for receiving the input bevel gear and a first half hole, an output drive gear, a handle drive base including a second hole for receiving the input bevel gear and a second half hole, and a handle drive shaft.

Abstract: A mounting system and method for security screens for use with double-hung windows and other windows having an integral screen track is disclosed. The mounting system and method according to the present invention reduces materials cost for manufacture of security screens while improving aesthetics of the installation, and permits installation of security screens either at the construction site or during window manufacture, while preserving the window manufacturer's warranty.

Abstract: A safe and convenient grille decorative flower structure comprises a horizontal frame, a mullion, and a flower body. The flower body is disposed in a window pane surrounded by the horizontal frame and the mullion, and the flower body is disposed in the horizontal frame or the mullion. The grille decorative flower structure is convenient to install or assemble, wherein the said structure is detachable and can be disassembled and mailed to clients to install or assemble by themselves. By a simple connection, the bonding strength of the whole framework is higher, and the said structure has an anti-theft effect.

Abstract: A frame for an air conditioning unit comprising a L or U shaped stability bar configured to receive a movable portion of a window, a plurality of coupling holes configured to couple the frame to the air conditioning unit, a security platform protruding from a posterior of the frame and a plurality of locking plates coupled to a front portion of the frame.

Abstract: A pet door is provided having a frame unit and a pivotal flap. The pet door includes a sill which is magnetically biased to attach to the lower end of the flap unit so as to maintain the flap unit in its closed position and to resist pressure differential forces applied to the flap unit, but to provide a lower degree of resistance at one or both of lower corners of the flap unit. The sill includes a first latch member extending from the sill which cooperates with a second latch member coupled to the bottom of the flap unit. At least one of the latch members may be frusto-conical in shape.

Abstract: A main support frame is formed from sections of a plastic extrusion and has opposite side portions with peripheral recesses receiving an inner sash unit and outer sash unit each having a frame formed from sections of a plastic extrusion and supporting an insulated glass unit. Hinges support the dual sash units for pivotal movement between open and closed positions, and gear connected telescopic link members connect the main frame to the sash frames for simultaneous movement. A lock system includes a handle on the inner sash unit for moving straps with studs on the sash frames through a connector mechanism mounted on the main frame for simultaneously locking and releasing both sash units and for releasing only the inner sash unit. A screen and/or mini-blind can be supported between the sash units, and the window system with dual sash units may be constructed in various forms.

Abstract: A window frame assembly has a built-in foldable screen, having a body, the body having at least a first frame part and a second frame part; the first frame part has at least a first end surface and a second end surface; the second end surface is fixedly connected to the second frame part; the first end surface is provided with a protruded guiding convex part; the guiding convex part is provided with a line receiving groove; and two sides of the line receiving groove are respectively provided with a concave part. The above structure has the benefits of enabling the guiding convex part located on the transverse frame in the foldable screen module to be re-assembled on the structure of the window frame assembly, thus reducing the number of foldable screen module components, and also improving the convenience of assembling the foldable screen module in the window.

Abstract: A garage door accessory is configured to increase ventilation into a garage. The garage door accessory includes at least one panel frame attached to at least one panel grate. At least one stow bar is attached to the panel frame. A lock assembly is attached to the panel grate and the panel frame; wherein the lock assembly further comprises a lock bar.

Abstract: A pet door system for allowing pets to enter and exit a building is provided. The pet door system comprises a pet door having a top edge, a pair of side edges, and a bottom edge with the pet door pivotally mounted within the opening. An aperture is formed in the top edge only of the pet door. A groove extends from along each side of the aperture. A plunger is moveable into and out of the aperture with the plunger riding in the groove. A solenoid moves the plunger into and out of the aperture with an activation mechanism activating the solenoid. Upon the activation mechanism being positioned within a predetermined distance from the pet door, the solenoid causes the plunger to automatically unlock the pet door. Upon the activation means being positioned outside the predetermined distance from the pet door, the solenoid causing the plunger to automatically lock the pet door.

Abstract: A main support frame is formed from sections of a plastic extrusion and has opposite side portions with peripheral recesses receiving an inner sash unit and outer sash unit each having a frame formed from sections of a plastic extrusion and supporting an insulated glass unit. Hinges support the dual sash units for pivotal movement between open and closed positions, and gear connected telescopic link members connect the main frame to the sash frames for simultaneous movement. A lock system includes a handle on the inner sash unit for moving straps with studs on the sash frames through a connector mechanism mounted on the main frame for simultaneously locking and releasing both sash units and for releasing only the inner sash unit. A screen and/or mini-blind may be supported between the sash units, and the window system with dual sash units may be constructed in various forms.

Abstract: The device includes two sub-assemblies (1) for mounting the rail (2) for supporting the curtain on the leaves (3) of the window, each sub-assembly having a plate (5) and an offset arm (6). The plate is formed so as to be able to be fixed to the upper edge of a leaf (3), in the vicinity of the pivot axis thereof, and includes mounting elements (14) for pivotably mounting the offset arm thereon, along an axis extending, after mounting on the leaf (3), parallel to the pivot axis of the leaf. The offset arm (6) is formed to offset the rail (2) relative to the wall; it is pivotably mounted on the plate (5) by the mounting elements and is pivotably connected to the rail (2) at a point thereof which is longitudinally fixed, also along an axis parallel to the pivot axis of the leaf (3).

Abstract: A main support frame is formed from sections of a plastic extrusion and has opposite side portions with peripheral recesses receiving an inner sash unit and outer sash unit each having a frame formed from sections of a plastic extrusion and supporting an insulated glass window unit. Hinges support the dual sash units for pivotal movement between open and closed positions, and gear connected telescopic link members connect the main frame to the sash frames for simultaneous movement. A lock system includes a handle on the inner sash unit for moving straps with studs on the sash frames through a connector mechanism mounted on the main frame for simultaneously locking and releasing both sash units and for releasing only the inner sash unit. A screen and/or mini-blind may be supported between the sash units, and the window system with dual sash units may be constructed in various forms.

Abstract: A window dressing system for installation within a window structure is disclosed. The window dressing system has at least one dressing element. The dressing element includes a frame structure and engagement members outwardly extendable from the frame structure and adapted to forcibly engage a surface of the window structure to maintain the dressing element fixed within the window structure. The engagement members on the frame are arranged in manner that several dressing elements may be modularly attached together. The engagement members may be replaced by linking members when attaching adjacent dressing systems together. A method for installing such a window dressing system is also disclosed.

Abstract: A security screen door (1) for vehicles comprises a frame (2) forming an opening, at least one sliding section (10, 12) within the frame and a quick action lever (21) on an inside of the door for locking and unlocking the door via a first lock (20). The sliding section comprises a second lock (14) for securing the sliding section in a closed position, the second lock being unlocked from an outside using a key to allow the sliding section to be moved from a closed position to an open position to allow access from the outside to the quick action lever.

Abstract: A screen assembly for installation in a fenestration product of the type having a window covering with a sliding operator. The screen assembly includes a screen frame having a screen material and is adapted to releasably attach to an interior side of the fenestration product. The screen assembly includes a screen operator slidable relative to the screen frame and releasably engagable with the sliding operator, such that the screen operator is operable from the interior side of the screen assembly.

Abstract: A door panel comprises several interlocking panel members. The panel members can be extrusions that are readily cut to length to create assembled door panels that match doorways of various widths. The ability to readily provide a door panel in various widths and lengths makes such a panel particularly useful as a replacement panel whose size needs to match that of existing door panels. In some embodiments, a physical property of the panel member's extruded material varies from one panel member to another and/or varies within a single panel member to provide a door panel with certain desirable characteristics.

Abstract: Sections of extruded rigid plastics material form a rectangular main frame including a pair of vertical jamb members, a top head member and a bottom sill member connected by welded mitered corners. An extruded plastic astragal member is spaced between the jamb members and has laterally projecting stop portions and internal walls which are rigidly connected by long screws to the head and sill members. A fixed door panel and a pivotal door panel have extruded plastic rectangular frames with welded mitered corner joints and which surround corresponding glazing panels. A continuous gear hinge has an inactive leaf secured to the astragal member and a slightly shorter active leaf. The door panel frames have internal walls which cooperate with the welded corner joints to maintain each frame flat, and long screws positively connect the leaves of the gear hinge to the pivotal door panel frame and the astragal member.

Abstract: A window system includes an out-swinging window having an exterior surface, and an interior surface. The viewable portions of the interior surface are made of a first material. The window system also includes a jamb. The out-swinging window is pivotally attached to the jamb. A screen assembly is removably mountable to the jamb on the interior surface of the out-swinging window. The screen assembly further includes a frame portion with a viewable portion made of the first material. In some embodiments, the window system further includes a finish strip positionable between the screen of the screen assembly and the frame of the screen assembly and a set of instructions regarding the window system.

Abstract: A door assembly includes a barrier door that is hingedly rotatable about an axis of rotation. The door assembly further includes an environmental door that is hingedly rotatable about the axis of rotation. The barrier door and the environmental door can be rotated independently or in unison from opened positions to closed positions. The barrier door has a handle and the environmental door has a hole through which the handle can pass so that the barrier door handle can be accessed through the environmental door. The environmental door also has a cover for selectively closing the handle hole.

Abstract: A window system includes an out-swinging window having an exterior surface, and an interior surface. The viewable portions of the interior surface are made of a first material. The window system also includes a jamb. The out-swinging window is pivotally attached to the jamb. A screen assembly is removably mountable to the jamb on the interior surface of the out-swinging window. The screen assembly further includes a frame portion with a viewable portion made of the first material. In some embodiments, the window system further includes a finish strip positionable between the screen of the screen assembly and the frame of the screen assembly and a set of instructions regarding the window system.

Abstract: A door assembly includes a barrier door that is hingedly rotatable about an axis of rotation. The door assembly further includes an environmental door that is hingedly rotatable about the axis of rotation. The barrier door and the environmental door can be rotated independently or in unison from opened positions to closed positions. The barrier door has a handle and the environmental door has a hole through which the handle can pass so that the barrier door handle can be accessed through the environmental door. The environmental door also has a cover for selectively closing the handle hole.

Abstract: A window system includes an out-swinging window having an exterior surface, and an interior surface. The viewable portions of the interior surface are made of a first material. The window system also includes a jamb. The out-swinging window is pivotally attached to the jamb. A screen assembly is removably mountable to the jamb on the interior surface of the out-swinging window. The screen assembly further includes a frame portion with a viewable portion made of the first material. In some embodiments, the window system further includes a finish strip positionable between the screen of the screen assembly and the frame of the screen assembly and a set of instructions regarding the window system.

Abstract: A window system includes an out-swinging window having an exterior surface, and an interior surface. The viewable portions of the interior surface are made of a first material. The window system also includes a jamb. The out-swinging window is pivotally attached to the jamb. A screen assembly is removably mountable to the jamb on the interior surface of the out-swinging window. The screen assembly further includes a frame portion with a viewable portion made of the first material. In some embodiments, the window system further includes a finish strip positionable between the screen of the screen assembly and the frame of the screen assembly and a set of instructions regarding the window system.

Abstract: An entryway system includes an elongated threshold assembly and a pair of plastic jamb boots attached to the ends of the threshold assembly. The jamb boots have flat level upper faces and a pair of jambs having square-cut bottoms are secured to the jamb boots and extend upwardly from the threshold assembly. A head jamb completes a door frame. The jamb boots may be formed with integral drains that receive water from within the threshold cap channel of the threshold assembly and direct it away from the entryway. The plastic jamb boots prevent rotting and eliminate the need to mill the bottoms of jambs with haunches configured to fit the threshold assembly. Plastic mull post boots also are provided for supporting square-cut bottom mull posts in sidelight or double door entryways.

Abstract: A door frame with a substantially continuous sealing surface supports a door with a substantially continuous sealing member mounted thereon. A stepped U-shapped frame member has an opening at one end that is closed with a square-cut member, such as a threshold. The frame, threshold and hinges mounted on the frame provide a substantially continuous sealing surface. The bores of the hinge knuckles may be matched with bushings in the bores, so that the bushings must be properly oriented. The heads of the bushings may have at least two steps or raised contact surfaces and at least two indentations or depressed contact surfaces. When the doors are opened, the steps on their bushings in the pivoting hinge leaves drop into the indentations in the adjacent fixed hinge leaf and hold the door in position.

Abstract: An apparatus and method for a slide/swing patio door including a frame having a first panel pivotally mounted on the frame and a second panel slidingly mounted in the frame in a plane adjacent to the first panel. The second panel slides toward the first panel until they are substantially congruent, at which time the first and second panels can be selectively moved out of the frame around a pivot of the first panel. Another embodiment includes a latch to couple the first panel and the second panel together before the panels can be moved around the pivot. An additional embodiment provides a lock pin mounted on the first panel configured to engage a box staple mounted on the frame. In addition, another embodiment further includes a guide mounted on the first panel aligned to engage the second panel, wherein the second panel is guided alongside of the first panel and supported by the guide on the first panel during movement around the pivot.

Abstract: The present application generally relates to door frame assemblies and door sill assemblies. One aspect relates to a door sill assembly having an open fluid receiving trough in its sub-sill. Another aspect relates to a door sill assembly having a tread structure that includes a lip for supporting a rectilinearly movable door panel with a groove adjacent the lip for guiding fluid on the tread structure to opposing ends thereof.

Abstract: One aspect of the present invention is directed to a screen door comprising a flexible screen and a rigid transparent protective cover disposed in at least partially overlapping relation with the flexible screen in order to protect the screen from damage. The cover is advantageously transparent in order to permit a person to see through both the screen and the cover. Furthermore, the cover is advantageously provided with a plurality of air holes.

Abstract: A window with an outer frame for mounting in a window opening in a structure this outer frame having on the sides thereof sash tracks or channels facing one another across the window space. Window sashes containing a single window pane are positioned between and securable in such channels in a manner allowing them to be slid therealong for opening and closing the window. Protuberances extending from the window frame secure the window sashes in the channels so as to allow sliding therealong, and removing such window sashes from those channels is accomplished by removing the protuberances therefrom. A blocking panel is positionable in the outer frame in the absence of such window sashes, and can be removed therefrom in the absence of such sashes but not when the sashes are present.

Abstract: An openable window comprises a main frame (1) and a sash (3) top-hinged therein, in which sash is mounted a light screen, particularly a Venetian blind (4), with an adjusting mechanism (5), as well as with a screening device (7, 8) which may be an insect screen mounted in the main frame internally of the window sash. A turning handle (15) is mounted at the internal side of the screening device and is via a shaft (18) connected with the light screen adjusting mechanism in a rotationally locked manner, said shaft being articulated with the adjusting mechanism and telescopically connected with a pivotable member (14). The Venetian blind can thus be operated also with an insect screen placed internally of the window sash and with the window in an opened position for ventilation. The pivotable member can be designed as a ball joint journalled in a double conical bearing or as a ball with a through bore where the shaft is designed as a round bar being integrally with the turning handle.

Abstract: In a window with a frame of extruded profile members the exterior side of an edge portion of a thermo pane is supported by a first flange portion of the profile member and the inside by a glazing bead connected with the frame profile member. The main frame mainly consists of wood profiles, the exterior sides of which are covered by weather-resisting coverings. A hinge member at the top of the window comprises an edge portion (28) of an extruded profile member (27) forming a hinge pivot firmly connected to the main frame portion (20) at this side and a hook-shaped wall portion (6) of the opposite frame profile member (1) forming a hinge blade. At one of the other sides of the window an arrangement is provided to ensure engagement of said hinge pivot and hinge blade forming portions in the closed position of the window.

Abstract: In a window with a frame of extruded profile members the exterior side of an edge portion of a thermo pane is supported by a first flange portion of the profile member and the inside by a glazing bead connected with the frame profile member. The main frame mainly consists of wood profiles, the exterior sides of which are covered by weather-resisting coverings. A hinge member at the top of the window comprises an edge portion (28) of an extruded profile member (27) forming a hinge pivot firmly connected to the main frame portion (20) at this side and a hook-shaped wall portion (6) of the opposite frame profile member (1) forming a hinge blade. At one of the other sides of the window means are provided to ensure engagement of said hinge pivot and hinge blade forming portions in the closed position of the window.

Abstract: A turnable window arrangement has a window sash to be rotated about a horizontal axis through approximately 180.degree. relative to a window frame. The window frame is provided with a separately removable air screening filter secured to the frame in a position inside the swinging path of said sash. A link arm mechanism is arranged to lock the sash in different positions between completely closed and opened venting positions.

Abstract: A weatherproof ventilating insert for a garage door or the like having a plurality of sections normally closed by imperforate panels. At least one of the panels is provided with an aperture. A pair of frames, including sun rays and rain shielding louvers in one frame, are disposed on respective opposite sides of the panel for receiving sheet material between the frames which may be a section of screening or an imperforate panel or both.

Abstract: A window assembly controls ventilation and prevents passage through the window opening. Provides hardened steel horizontal bars spaced apart vertically a distance that prevents passage. The bars are welded to hardened steel frame members. The steel assembly is anchored in the wall by resistant anchoring elements. The bars may be secured in place by other means. Glazed aluminum vents have top rails that enclose the bars and pivot upon them. Aluminum frame members enclose the steel frame members and support operator means that rotate the vents on the bars to open and close the vents. The angle of opening may be limited to prevent the vent extending beyond the wall at walkways.

Abstract: A removable, insulated window covering in the form of two insulated, bifolding panels hinged together and mounted over a window are foldable from a position covering the window to a nested storage position above the window. Side and edge seals are provided, as well as folding and latching mechanisms, for moving the panels between the use and storage positions and for retaining the panels in those positions.

Abstract: A flexible, resilient pet door flap hung in a frame so that it is movable in the horizontal direction between vertical side walls has peripheral Z-shaped edge portions terminating in web portions for effecting a seal against the side walls. The bottom portion of the frame includes a movable sill with magnets corresponding to magnets in the flap, and a secured piston in the frame having a surface adjacent a surface of the sill, with viscous material therebetween, to inhibit movement of the sill.

Abstract: A boat window having a removable screen which, in one embodiment, directly carries a louver and which can be easily installed in the window frame or removed therefrom as a single unit, so as to facilitate replacement with a conventional window screen, if desired. The louver forms a water shield which directly engages the screen frame adjacent to its top edge, so as to reduce the likelihood of water splashing through upper portions of the screen. The window comprises a frame body having a mounting flange and spigot, for installation in an opening in the boat hull. A window pane is hingedly connected to the mounting flange, and adapted to close off the space formed by the spigot. Most or all portions of the louver lie within the confines of the spigot, so as not to protrude any substantial extent, thereby reducing the likelihood of damage to the louver from inadvertent contact with other objects.

Abstract: A boat window having a removable screen which, in one embodiment, directly carries a louver and which can be easily installed in the window frame or removed therefrom as a single unit, so as to facilitate replacement with a conventional window screen, if desired, The louver forms a water shield which directly engages the screen frame adjacent to its top edge, so as to reduce the likelihood of water splashing through upper portions of the screen. The window comprises a frame body having a mounting flange and spigot, for installation in an opening in the boat hull. A window pane is hingedly connected to the mounting flange, and adapted to close off the space formed by the spigot. Most or all portions of the louver lie within the confines of the spigot, so as not to protrude any substantial extent, thereby reducing the likelihood of damage to the louver from inadvertent contact with other objects.

Abstract: This invention is concerned with devices for controlling movement of small animals, of the kind commonly known as "Cat Ports". The device is activated by an operating magnet worn by the small animal, which when the animal moves to pass through the device, closes a reed switch. The reed switch is adjustably pre-biased by a positionally adjustable permanent magnet, to afford the reed switch with a desired sensitivity, and a control circuit includes a re-setting coil to return the reed switch to its open position after a predetermined time interval. The device may readily be modified to control movement of animals in either, or both directions, to and from a designated area.

Abstract: An air screen for vehicle sunroofs extends between the leading edges of an open sunroof panel and the vehicle's roof to regulate intake air flow and prevent potentially dangerous projectiles from being carried into the vehicle's interior along with the air flow. The air screen is formed from flexible plastic material and deflects into a storage position when the sunroof panel is pivoted from an open scoop position to a closed position. The air screen may be secured to either the sunroof panel or the roof and consists of two halves slidable relative to each other so as to permit regulation of the air flow therethrough. The air screen also functions as an air deflector to prevent wind buffeting effects when the panel is completely removed from the roof.

Abstract: A casement window is operable in a vent-egress mode and a wash mode. Hinge assemblies are mounted to the sash and hinge lock assemblies are engaged by the hinge assemblies. Both hinge and hinge lock assemblies are slidably mounted to channel-forming slides on the window frame. The lock assemblies releasably lock the sash in the vent-egress and wash modes.

Abstract: A self-draining, leak-resistant boat window comprising a frame body having a continuous mounting flange for engagement with an inner surface surrounding an opening in the boat hull. The body has a spigot which is connected with the mounting flange. A low portion of the spigot has an upwardly facing drain surface constituting a sill. The sill has a downwardly offset portion provided with a sloping, upwardly-open drain groove which extends from a high location adjacent the mounting flange to a low location, remote from the mounting flange. The arrangement is such that water which is splashed onto the sill is channeled toward the offset portion, and thereby drained away. There is thus minimized the tendency for water to collect on the sill and leak into the boat interior when the window pane is opened.

Abstract: An improvement in casement windows provides a mullion portion which is removable to allow for emergency egress through the window, a pivotably disengagable connection being formed between one end of the mullion portion and the head jamb of the window frame, and a tongue and groove connection being formed between downwardly and outwardly inclined complementary surfaces on the other end of the mullion portion and the sill of the window frame that allows the mullion portion to slide outwardly from a position seated in the frame to effect separation of the mullion portion from the frame simply upon opening of a sliding latch.

Abstract: Doors and windows of the louver type are protected against unauthorized entry and against severe storm conditions by having a channeled frame member positioned interiorly of the door or window aperture, a solid panel received within said channeled frame member and adjustable lock means to lock the solid panel in the frame member from the interior side.

Abstract: An integral window unit comprising a sill member, a header member and a pair of jamb members interconnected to form a generally rectangular window frame. The jamb members have first and second pairs of track means each pair of which slideably receives a prime window sash and third and fourth pairs of track means each pair of which slideably receives a storm window sash. The distance between the track members in the first pair is greater than the distance between the track members in the second pair which in turn is greater than the distance between the third pair which is greater than the distance between the fourth pair. At least one pair of track means is in overlapping relationship with the adjacent pair of track means. A thermal barrier is provided in the window frame between the second and third pair of track members to minimize heat loss therethrough and a fifth pair of track means is provided adjacent the thermal barrier for slideably receiving a screen member.

Abstract: A convertible door structure for hinged mounting in a conventional door frame and including bottom and upper panel portions normally bounded by opposed side stiles and top and bottom cross rails; the lower panel portion is fixed relative to the lower portions of the side stiles and the bottom cross rail. The upper panel portion is hinged along its bottom edge to the top edge of the bottom panel portion in a manner whereby it may be swung from its normal closed position, relative to the top halves of the side stiles and the top cross rail to an open position wherein it overlies the inner face of the bottom panel portion. A pocket or well is defined within the lower panel portion to store a generally conventional type of framed screen unit for selective removal and installation in the opening defined in the upper portion of the door when the upper panel portion is disposed in its down position.

Abstract: An adjustable window guard and screen apparatus includes an adjustable framework of two sections slidably mated to each other. Also, at least one set of screen members, and a plurality of bar members are affixed to the framework and are expandable or contractable upon the adjustment of the framework. Louver members having two slidably mating sections are further included and are each in engagement with a bar member. At least one section of a bar member having a louver member mounted thereon, is itself rotatably mounted to the framework. The louver member is mounted to the bar member so that rotation of the rotatably mounted bar member section causes rotation of the louver member. Like the screen members and bar members, the louver members will expand or contract upon the adjustment of the framework.

Abstract: An improved wall ventilator for use in building constructions comprising a housing having a peripheral wall member defining an air flow passageway, a first louver section comprising a fixed panel having a plurality of openings therethrough and attached to said peripheral wall members to extend across a front portion of the passageway, a second movable louver section comprising a plurality of movable panels extending in side by side relation and having a plurality of openings extending therethrough and alternately spaced with respect to the openings in the first louver section fixed panels whereby imperforate portions of each section of panels overlie the openings of the other when the movable second section panels are located in a common plane and in a first position immediately adjacent the rear face of the fixed panel to close the housing passageway, and a temperature responsive bimetallic spring operatively connected to the movable panels to pivot the same away from the first fixed panel to a second positi