Attic inlet

Abstract

An attic inlet has a square tube to communicate between an attic and a room through a substrate, and a lid to permit airflow through the inlet when open, and prevent it when closed. The lid is moved by an upper pull bar and lower connecting bars attached to the lid. Upper pull bar and lower connecting bars are attached by clevis pins to yoke arms pivoting about parallel axles. Movement of the upper pull bar rotates the yoke arms, and so lowers the connecting bars and the attached lid. Springs urge pull bar and lid into closed default position, while a cord is used to displace pull bar and lid into open position. The lid is attached by tabs on the connecting bars passing through the lid, and lid locking bars engaging apertures in the tabs.

1 . Air inlet for ventilation comprising an upper aperture and a lower aperture joined by a tubular passage defined by surrounding side walls extending between said apertures,
 said upper aperture having a generally planar edge and said upper aperture being adapted to allow airflow from a corresponding aperture in a substrate,   said lower aperture having a planar edge generally parallel to the edge of said upper aperture and locatable below said substrate, said lower aperture having a lid movable between a closed position blocking said passage, and at least one open position allowing air flow through said passage,   said tubular passage being generally rectangular in cross section,   said side walls forming two pairs of opposed parallel walls connected at their side edges,   spaced apart parallel first and second axles extending between one pair of opposed parallel side walls, each axle having two yokes mounted thereon adjacent said side walls, said yokes having a central disk and first and second arms extending outward from said disk at an acute angle,   an upper metal pull bar substantially parallel to a plane formed by said axles, and said pull bar being joined to said yokes by first clevis pins journalled in said pull bar and said first arms of said yokes,   two lower plastic connecting bars aligned substantially perpendicular to said axles, said connecting bars being joined to said yokes by second clevis pins journalled in said connecting bars and said second arms of said yokes,   said lower plastic connecting bars being attached to said lid,   said pull bar having a default position wherein said lid is in closed position,   said yokes being rotatable from said default position where said arms are generally upward and said clevis pins aligned parallel to said edges of said upper and lower apertures, when said pull bar is displaced from said default position away from said first axle toward said second axle said yokes are angularly rotated away from said default position so said first arms are closer to said edge of said upper aperture and said second arms are closer to the edge of said lower aperture, whereby said lower plastic connecting bars are displaced away from said edge of said upper aperture, and said lid is displaced away from said edge of said lower aperture into an open position, the angle of rotation of said yokes determining the displacement of said lid.   
     
     
         2 . Inlet of  claim 1 , wherein said axles have square end sleeves, which matingly engage square apertures in said yokes. 
     
     
         3 . Inlet of  claim 2 , wherein said first axle has a square cross section. 
     
     
         4 . Inlet of  claim 1 , wherein said upper aperture has a generally planar edge and a surrounding planar lip extending generally perpendicular to said side walls, said lip being adapted to fit against a substrate,
 said upper metal pull bar having side rails substantially perpendicular to said axles, and cross rails joining said side rails parallel to said axles, said side rails being joined to said yokes by first clevis pins journalled in said side rails and said first arms of said yokes,   said lower plastic connecting bars extending downward to said lid and being attached thereto.   
     
     
         5 . Air inlet of  claim 4 , wherein said connecting bars have end projections extending the same distance downward, said projections having downward tabs at their bottom, said downward tabs having therein apertures, said apertures being substantially at right angles to said connecting bars
 said lid having four apertures to register with said tabs of said connecting bars, said tabs when registered passing through said lid   paired lid locking bars on the lower surface of said lid parallel to said axles engaging said apertures of said tabs of said connecting bars at both ends, and holding said lid in fixed relation to said connecting bars.   
     
     
         6 . Air inlet of  claim 5 , wherein each said lid locking bar has a central tab to engage a recess in said lower surface of said lid. 
     
     
         7 . Air inlet of  claim 6 , wherein each said lid locking bar has central wings extending perpendicular to said lid locking bar on either side. 
     
     
         8 . Air inlet of  claim 1  wherein said side walls comprise paired opposed cross walls parallel to said axles. 
     
     
         9 . Air inlet of  claim 8  wherein at least one spring is attached to a first cross wall adjacent said first axle, and to a first cross rail of said pull bar adjacent said first axle, said spring urging said pull bar into said default position. 
     
     
         10 . Air inlet of  claim 9  wherein a cord passes through an aperture in a second cross wall adjacent said second axle and is attached to a second cross rail of said pull bar adjacent said second axle, whereby said cord can displace said pull bar from said default position toward an open position. 
     
     
         11 . Air inlet for ventilation comprising an upper aperture and a lower aperture joined by a tubular passage defined by surrounding side walls extending between said apertures,
 said upper aperture having a generally planar edge and said upper aperture being adapted to allow airflow from a corresponding aperture in a substrate,   said lower aperture having a planar edge generally parallel to the edge of said upper aperture and locatable below said substrate, said lower aperture having a lid movable between a closed position blocking said passage, and at least one open position allowing air flow through said passage,   said tubular passage being generally rectangular in cross section,   said side walls forming two pairs of opposed parallel walls connected at their side edges,   the improvement comprising spaced apart parallel first and second axles extending between one pair of opposed parallel side walls, each axle having two yokes mounted thereon adjacent said side walls, said yokes having a central disk and first and second arms extending outward from said disk at an acute angle,   an upper metal pull bar substantially parallel to a plane formed by said axles, and said pull bar being joined to said yokes by first clevis pins journalled in said pull bar and said first arms of said yokes,   two lower plastic connecting bars aligned substantially perpendicular to said axles, said connecting bars being joined to said yokes by second clevis pins journalled in said connecting bars and said second arms of said yokes,   said lower plastic connecting bars being attached to said lid,   said pull bar having a default position wherein said lid is in closed position,   said yokes being rotatable from said default position where said arms are generally upward and said clevis pins aligned parallel to said edges of said upper and lower apertures, when said pull bar is displaced from said default position away from said first axle toward said second axle said yokes are angularly rotated away from said default position so said first arms closer to said edge of said upper aperture and said second arms closer to the edge of said lower aperture, whereby said lower plastic connecting bars are displaced away from said edge of said upper aperture, and said lid is displaced away from said edge of said lower aperture into an open position, the angle of rotation of said yokes determining the displacement of said lid.   
     
     
         12 . Inlet of  claim 11 , wherein said axles have square end sleeves, which matingly engage square apertures in said yokes. 
     
     
         13 . Inlet of  claim 12 , wherein said first axle has a square cross section. 
     
     
         14 . Inlet of  claim 11 , wherein said upper aperture has a generally planar edge and a surrounding planar lip extending generally perpendicular to said side walls, said lip being adapted to fit against a substrate,
 said upper metal pull bar having side rails substantially perpendicular to said axles, and cross rails joining said side rails parallel to said axles, said side rails being joined to said yokes by first clevis pins journalled in said side rails and said first arms of said yokes,   said lower plastic connecting bars extending downward to said lid and being attached thereto.   
     
     
         15 . Air inlet of  claim 14 , wherein said connecting bars have end projections extending the same distance downward, said projections having downward tabs at their bottom, said downward tabs having therein apertures, said apertures being substantially at right angles to said connecting bars
 said lid having four apertures to register with said tabs of said connecting bars, said tabs when registered passing through said lid   paired lid locking bars on the lower surface of said lid parallel to said axles engaging said apertures of said tabs of said connecting bars at both ends, and holding said lid in fixed relation to said connecting bars.   
     
     
         16 . Air inlet of  claim 15 , wherein each said lid locking bar has a central tab to engage a recess in said lower surface of said lid. 
     
     
         17 . Air inlet of  claim 16 , wherein each said lid locking bar has central wings extending perpendicular to said lid locking bar on either side. 
     
     
         18 . Air inlet of  claim 11  wherein said side walls comprise paired opposed cross walls parallel to said axles,
 and in at least one spring is attached to a first cross wall adjacent said first axle, and to a first cross rail of said pull bar adjacent said first axle, said spring urging said pull bar into said default position, 
 and a cord passes through an aperture in a second cross wall adjacent said second axle and is attached to a second cross rail of said pull bar adjacent said second axle, whereby said cord can displace said pull bar from said default position toward an open position. 
 
     
     
         19 . Attic air inlet for ventilation comprising an upper aperture and a lower aperture joined by a tubular passage defined by surrounding side walls extending between said apertures,
 said upper aperture having a generally planar edge and a surrounding planar lip extending generally perpendicular to said side walls, said lip being adapted to fit against a substrate, and said upper aperture being adapted to allow airflow from a corresponding aperture in a substrate,   said lower aperture having a planar edge generally parallel to the edge of said upper aperture and locatable below said substrate, said lower aperture having a lid movable between a closed position blocking said passage, and at least one open position allowing air flow through said passage,   said tubular passage being generally rectangular in cross section,   said side walls forming two pairs of opposed parallel walls connected at their side edges,   spaced apart parallel first and second axles extending between one pair of opposed parallel side walls, each axle having two yokes mounted thereon adjacent said side walls, said yokes having a central disk and first and second arms extending outward from said disk at an acute angle,   an upper metal pull bar substantially parallel to a plane formed by said axles, and said pull bar having side rails substantially perpendicular to said axles, and cross rails joining said side rails parallel to said axles, said side rails being joined to said yokes by first clevis pins journalled in said side rails and said first arms of said yokes,   said axles having square end sleeves, which matingly engage square apertures in said yokes,   said first axle having a square cross section,   two lower plastic connecting bars aligned substantially perpendicular to said axles, said connecting bars being joined to said yokes by second clevis pins journalled in said connecting bars and said second arms of said yokes,   said lower plastic connecting bars connecting bars extending downward to said lid and being attached thereto,   said pull bar having a default position wherein said lid is in closed position,   said yokes being rotatable from said default position where said arms are generally upward and said clevis pins aligned parallel to said edges of said upper and lower apertures, when said pull bar is displaced from said default position away from said first axle toward said second axle said yokes are angularly rotated away from said default position so said, first arms closer to said edge of said upper aperture and said second arms closer to the edge of said lower aperture, whereby said lower plastic connecting bars are displaced away from said edge of said upper aperture, and said lid is displaced away from said edge of said lower aperture into an open position, the angle of rotation of said yokes determining the displacement of said lid.   
     
     
         20 . Attic air inlet of  claim 19 , wherein said connecting bars have end projections extending the same distance downward, said projections having downward tabs at their bottom, said downward tabs having therein apertures, said apertures being substantially at right angles to said connecting bars
 said lid having four apertures to register with said tabs of said connecting bars, said tabs when registered passing through said lid   paired lid locking bars on the lower surface of said lid parallel to said axles engaging said apertures of said tabs of said connecting bars at both ends, and holding said lid in fixed relation to said connecting bars, and   each said lid locking bar has a central tab to engage a recess in said lower surface of said lid and   each said lid locking bar has central wings extending perpendicular to said lid locking bar on either side and   said side walls comprise paired opposed cross walls parallel to said axles and   at least one spring is attached to a first cross wall adjacent said first axle, and to a first cross rail of said pull bar adjacent said first axle, said spring urging said pull bar into said default position and   a cord passes through an aperture in a second cross wall adjacent said second axle and is attached to a second cross rail of said pull bar adjacent said second axle, whereby said cord can displace said pull bar from said default position toward an open position.