Nozzle damper assembly

A nozzle damper assembly for installation in a duct operative for measuring and controlling the flow of a gaseous medium through the duct comprising:

• a. enclosure means mountable in installed relation at a location along the length of the duct, said enclosure means including a damper body embodying four sidewalls with two of said four sidewalls extending in parallel relation to one another and in perpendicular relation to the other two of said four sidewalls;
• b. shaft means supported for movement in said enclosure means, said shaft means including a pair of shaft members supported in spaced relation one to another;
• c. damper blade means mounted on said shaft means for rotatable movement within said enclosure means, said damper blade means including a pair of damper blades, each one of said pair of damper blades comprising a 90.degree. arc and having a radius equal to one-half of the height of the duct, each of said pair of damper blades further having a fixed end and a free end, one of said pair of damper blades having said fixed end thereof mounted on one of said pair of shaft members for movement therewith and the other one of said pair of damper blades having said fixed end thereof mounted on the other one of said pair of shaft members for movement therewith;
• d. damper blade operating means operatively connected to said damper blade means, said damper blade operating means being operative to effect the movement of each one of said pair of damper blades between a first position and a second position such that when each one of said pair of damper blades occupies the first position thereof said free end of one of said pair of damper blades is positioned in abutting relation to one of said sidewalls of said damper body and said free end of the other one of said pair of damper blades is positioned in abutting relation to another one of said sidewalls of said damper body and when each one of said pair of damper blades occupies the second position thereof said free ends of said pair of damper blades are positioned in abutting relation to each other, said damper blade operating means including a lever arm, a connecting link, a handle member and locking means, said lever arm being connected intermediate its ends to one of said pair of shaft members, said lever arm also having one end thereof connected to one end of said connecting link, said handle member having one end thereof connected to the other one of said pair of shaft members, said handle member also being connected intermediate its ends to the other end of said connecting link such that when said handle member is moved both of said pair of shaft members are rotatrd so as to cause said pair of damper blades to move in unison to and from relative to each other, said locking means having a locking position and an unlocking position, said locking means when in the locking position thereof being operative to lock said lever arm against movement and thereby causing said pair of shaft members as well as said connecting link and said handle member also to be locked against movement and when in the unlocking position thereof said locking means being operative to free said lever arm for movement thereby enabling said lever arm as well as said connecting link and said pair of shaft members to undergo movement in response to said handle member being moved;
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• e. flow measurement means operative to measure the flow of the gaseous medium through the nozzle damper assembly such that control can be exercised over the flow of the gaseous medium through the damper assembly and thereby through the duct based on the measurements obtained through the operation of said flow measurement means, said flow measurement means including first pressure sensing equipment located upstream of said fixed ends of said pair of damper blades and second pressure sensing equipment located at the position occupied by said free ends of said pair of damper blades when said free ends of said pair of damper blades are in the second position thereof.