Damper blade and damper blade assembly for an air duct

Abstract

A damper plate assembly adapted for installation in a circular air duct having tubular walls defining a bore about a central air flow axis with a set of coaxial apertures in opposing walls, the damper plate assembly including: a. a disk-like damper plate having (i) a central body part with a peripheral edge region, and a set of first and second holes extending transversely through the damper plate and situated along a diametrical line 180 degrees apart in first and second opposite portions respectively of the peripheral edge region, and (ii) a finger-like projection extending in the plane of the disk radially outward of the first peripheral edge region along the diametrical line, and b. first and second pivot elements adapted to engage the first and second opposite peripheral portions, the first pivot element having a body part with proximal and distal ends along a central longitudinal axis and extending axially from the distal end a set of two fingers which have a closed unflexed state where the fingers are generally closely parallel, the fingers being resiliently bendable apart from each other to a flexed state and biased to return to their closed state, one of the fingers including a projection extending transversely of the central longitudinal axis toward the other finger, and the other finger having a recess into which the projection extends when the fingers are in their closed state.

1 . A damper plate assembly adapted for installation in a circular air duct having tubular walls defining a bore about a central air flow axis with a set of coaxial apertures in opposing walls, comprising:
 a. a disk-like damper plate having (i) a central body part with a peripheral edge region, and a set of first and second holes extending transversely through said damper plate and situated along a diametrical line 180 degrees apart in first and second opposite portions respectively of said peripheral edge region, and (ii) a finger-like projection extending in the plane of said disk radially outward of said first peripheral edge region along said diametrical line, and   b. first and second pivot elements adapted to engage said first and second opposite peripheral portions, said first pivot element comprising a body part with proximal and distal ends along a central longitudinal axis and extending axially from said distal end a set of two fingers which have a closed unflexed state where said fingers are generally closely parallel, said fingers being resiliently bendable apart from each other to a flexed state and biased to return to their closed state, one of said fingers including a projection extending transversely of said central longitudinal axis toward the other finger, and the other finger having a recess into which said projection extends when said fingers are in their closed state, said first pivot element adapted to have its fingers inserted inwardly through one of said apertures in said duct wall to engage and sandwich between them said first portion of said peripheral edge of said plate with said projection of one finger inserted through said first hole in said plate's peripheral edge region and into said recess of said other finger for locking engagement of said pivot element with said damper plate,   c. said second pivot element having a similar body part and set of fingers as said first pivot element for being similarly insertable inwardly through said second of said apertures in said duct wall, for engaging said second peripheral edge region of said plate and said second hole through said plate,   d. said second pivot element further comprising on its body part at least one wall-engaging projection extending transversely of its central longitudinal axis and adapted to engage edges of said duct wall in the vicinity of said aperture in said duct wall to restrain said body part from moving axially outward of said aperture after said second pivot element has been inserted into said aperture, and   e. a fastening element adapted to cooperate with said body part of said second pivot element for securing said second pivot element and damper plate coupled thereto by said set of fingers of said second pivot element in a selected rotatable position about its central longitudinal axis relative to said duct wall.   
     
     
         2 . A damper plate assembly according to  claim 1  further comprising a turning handle extending generally perpendicularly and rigidly from said proximal end of said second pivot element. 
     
     
         3 . A damper plate assembly according to  claim 1  further comprising a washer-seal element in the form of a cylinder having a bore through which is extendable said second pivot element, and one end surface perpendicular to the central axis of said cylinder, and an opposite end surface defining a concave shape conforming to the convex outer surface of the duct, said washer-seal element being positionable coaxially between said fastener and said duct wall outer surface. 
     
     
         4 . A damper plate assembly adapted for installation in an air duct having tubular walls defining a bore about a central air flow axis with a set of coaxial apertures in opposing walls, comprising:
 a. a damper plate having (i) a central body part with a peripheral edge region adapted to conform to and fit within said duct bore, and a set of first and second holes extending transversely through said damper plate and situated along a diametrical line 180 degrees apart in first and second opposite portions respectively of said peripheral edge region, and (ii) a finger-like projection extending in the plane of said damper plate radially outward of said first peripheral edge region along said diametrical line, and   b. first and second pivot elements adapted to engage said first and second opposite peripheral edge portions respectively, said first pivot element comprising a body part with proximal and distal ends along a central longitudinal axis and extending axially from said distal end a set of two fingers which have a closed unflexed state where said fingers are generally closely parallel, said fingers being resiliently bendable apart from each other to a flexed state and biased to return to their closed state, one of said fingers including a projection extending transversely of said central longitudinal axis toward the other finger, and the other finger having a recess into which said projection extends when said fingers are in their closed state, said first pivot element adapted to have its fingers inserted inwardly through one of said apertures in said duct wall to engage and sandwich between them said first portion of said peripheral edge of said plate with said projection of one finger inserted through said first hole in said plate's peripheral edge region and into said recess of said other finger for locking engagement of said pivot element with said damper plate,   c. said second pivot element having a similar body part and set of fingers as said first pivot element for being similarly insertable inwardly through said second of said apertures in said duct wall, for engaging said second peripheral edge region of said plate and said second hole through said plate,   d. said second pivot element further comprising on its body part at least one wall-engaging projection extending transversely of its central longitudinal axis and adapted to engage edges of said duct wall in the vicinity of said aperture in said duct wall to restrain said body part from moving axially outward of said aperture after said second pivot element has been inserted into said aperture, and   e. a fastening element adapted to cooperate with said body part of said second pivot element for securing said second pivot element and damper plate coupled thereto by said set of fingers of said second pivot element in a selected rotatable position about its central longitudinal axis relative to said duct wall.   
     
     
         5 . A damper plate adapted for installation in a circular air duct having tubular walls about a central air flow axis, comprising:
 a disk-like central body part with a peripheral edge region and a set of two holes extending transversely through said plate and situated along a diametrical line 180 degrees apart in first and second opposite portions of said peripheral edge region, and a finger-like projection extending in the plane of said disk radially outward of said peripheral edge region along said diametrical line.   
     
     
         6 . A damper plate according to  claim 5  wherein said disk is a substantially flat sheet, and said finger-like projection is a contiguous part of said sheet 
     
     
         7 . A damper plate according to  claim 5  wherein each of said holes is elongated in the direction of said diametrical line. 
     
     
         8 . A damper plate according to  claim 5  wherein said finger-like projection has width in the range of about ⅛ to ¼ inch, and length in the range of about ½ to 1 inch. 
     
     
         9 . A pivot element for a disk-like damper plate used in an air duct damper assembly, where said damper plate has a central body part with a peripheral edge region and a set of first and second holes extending transversely through said plate and situated along a diametrical line 180 degrees apart in first and second opposite peripheral edge portions respectively,
 said pivot element adapted to engage one of said peripheral edge portions, said pivot element comprising a body part with proximal and distal ends along a central longitudinal axis, and extending axially from said distal end a set of two fingers which have a closed unflexed state where said fingers are generally closely parallel, said fingers being resiliently bendable apart from each other to a flexed state and biased to return to their closed state and biased to return to their closed state, one of said fingers including a projection extending transversely of said central longitudinal axis toward the other finger, and the other finger having a recess into which said projection extends when said fingers are in their closed state, for locking engagement of said pivot element with said damper plate.   
     
     
         10 . A combination air duct and damper plate assembly, comprising
 a. a length of a circular air duct having tubular walls defining a bore about a central air flow axis with a set of coaxial apertures in opposing walls,   b. a disk-like damper plate having (i) a central body part with a peripheral edge region, and a set of first and second holes extending transversely through said damper plate and situated along a diametrical line 180 degrees apart in first and second opposite portions respectively of said peripheral edge region, and (ii) a finger-like projection extending in the plane of said disk radially outward of said first peripheral edge region along said diametrical line, and   c. first and second pivot elements adapted to engage said first and second opposite peripheral portions, said first pivot element comprising a body part with proximal and distal ends along a central longitudinal axis and extending axially from said distal end a set of two fingers which have a closed unflexed state where said fingers are generally closely parallel, said fingers being resiliently bendable apart from each other to a flexed state and biased to return to their closed state, one of said fingers including a projection extending transversely of said central longitudinal axis toward the other finger, and the other finger having a recess into which said projection extends when said fingers are in their closed state, said first pivot element adapted to have its fingers inserted inwardly through one of said apertures in said duct wall to engage and sandwich between them said first portion of said peripheral edge of said plate with said projection of one finger inserted through said first hole in said plate's peripheral edge region and into said recess of said other finger for locking engagement of said pivot element with said damper plate,   d. said second pivot element having a similar body part and set of fingers as said first pivot element for being similarly insertable inwardly through said second of said apertures in said duct wall, for engaging said second peripheral edge region of said plate and said second hole through said plate,   e. said second pivot element further comprising on its body part at least one wall-engaging projection extending transversely of its central longitudinal axis and adapted to engage edges of said duct wall in the vicinity of said aperture in said duct wall to restrain said body part from moving axially outward of said aperture after said second pivot element has been inserted into said aperture, and   f. a fastening element adapted to cooperate with said body part of said second pivot element for securing said second pivot element and damper plate coupled thereto by said set of fingers of said second pivot element in a selected rotatable position about its central longitudinal axis relative to said duct wall.