Abstract:
An adjustable regulator and lock device for a pivotally rotatable damper adapted for installation in an air duct of an HVAC system is disclosed, which includes a pivot rod rotatably attached to the air duct and arranged for rotation with the damper. The pivot rod has coupled to it, a lockdown member having a plurality of radially extending teeth extending outwardly therefrom. A plate member is fixedly spaced from the air duct and has a plurality of correspondingly shaped and dimensioned tooth-shaped cutouts adapted to receive the teeth of the lockdown member to selectively lock the rotational position of the pivot rod and the damper in a selected angular orientation. The teeth of the lockdown member are biased by a coil spring toward engagement with the cutouts of the plate member, and yet selectively releaseable therefrom. The invention provides secure and locked positioning of the damper.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to U.S. provisional application No. 61/649,812, filed May 21, 2012, the disclosure of which is incorporated by reference herein its entirety, and made a part of this application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an adjustable regulator and lock device for controlling the flow of conditioned air in ducts of heating, ventilating and air conditioning systems, commonly referred to as “HVAC” systems. In particular, the present invention relates to a damper adjustment and positioning lock. 
     2. Description of the Related Art 
     It is well known in ducted heating, ventilating or air conditioning systems to provide, at selected locations, regulating damper assemblies for controlling the rate of flow of air or the like through the ducts of the HVAC system. Such known ductwork damper assemblies generally include a damper blade made of sheet metal and dimensioned to conform substantially to the cross-section of the air duct intended for passage of air or the like in a regulated manner. In general, the damper blade has a circular shape and is fitted in a circular air duct of slightly larger diameter to permit pivotal rotation of the damper blade. The damper blade is rotatably attached to a shaft (i.e., pivot rod) which is itself rotatably connected to the duct by bearing-type bushings, such that the blade is pivotable within the duct as the shaft is rotated. One end of the shaft extends outwardly from the duct and is pivotally rotatable through a lever or other device, to one of a number of selected angular orientations to control the airflow through the duct. Various types of known devices using levers of various types are used to rotate the damper blade and to fix it in a pre-selected angular orientation. 
     Generally, rotation of the lever causes the damper blade shaft to rotate within the duct, and thereby produce corresponding rotation of the damper blade. The damper blade may be rotated between an open position where the air duct is in a fully open configuration, allowing air to pass therethrough, and a closed position, whereby the flow of air is blocked, causing it to be diverted in a different direction to a different location. 
     Various devices have been made to improve the ability to pivot and fix such damper blades to a particular angular orientation within the air duct between fully open and fully closed configurations. For example, various arrangements of levers and wingnut-type locking mechanisms have been incorporated to manually pivot and fix the position of the damper blade. These arrangements however, are cumbersome to use, and as well, do not provide sufficiently stable and fixed positioning of the damper blade when locked in position. Moreover, they do not provide an easily visible indicator to the user of the position of the damper, which is always hidden from view within the ductwork assembly. 
     The present invention is directed to an adjustable regulator and lock device for adjusting a damper in the air duct of a ductwork assembly, for the purpose of controlling the flow of conditioned air therethrough. In particular, the present invention provides fixed and stable adjustment of the damper blade orientation through the engagement of a multiplicity of engaging lockdown teeth with a corresponding multiplicity of complementary controlling tooth shaped cutouts in a fixed plate member mounted adjacent the air duct, while yet providing a ready and visible display indicator to the user of the actual angular position of the damper. 
     SUMMARY OF THE INVENTION 
     An adjustable regulator and lock device for a damper adapted for installation in an air duct is disclosed, which comprises an elongated member coupled to the damper for rotation therewith, the elongated member having a generally longitudinal rotational axis, a plate member positioned adjacent and outside of the air duct, the plate member having an opening through which the elongated member extends. A lockdown member has a plurality of outwardly extending engagement devices rotatably coupled with the elongated member and movable toward and away from the plate member in directions extending along the longitudinal axis. A plurality of correspondingly positioned, configured and dimensioned mating engagement devices are associated with the plate member, the engagement devices of the plate member being adapted to engage with the engagement devices on the elongated member when the elongated member and the damper are rotated to a selected angular position, and the engagement devices coupled with the elongated member are placed into engagement with the engagement devices of the plate member to prevent rotation of the elongated member and thereby fix the angular orientation of the damper. 
     The lockdown member preferably comprises a plurality of radially outwardly extending teeth. The plurality of mating engagement devices of the plate member preferably comprise a plurality of tooth-shaped cutouts in the plate member, configured similar to the cross-sectional shape of the radially extending teeth of said lockdown member. 
     The radially outwardly extending teeth coupled with the lockdown member are preferably triangular in shape. 
     In an alternative embodiment the outermost dimension of the radially outwardly extending teeth is progressively increased as measured along the length of the elongated member and in a direction extending from the plate member toward the duct, such that the lockdown member and the teeth have a generally tapered side elevational profile. 
     The plurality of teeth are movable longitudinally with respect to the plate member for respective receptive engagement and disengagement with the plurality of tooth-shaped cutouts of the plate member, to thereby fix the angular orientation of the longitudinal member and the damper. Preferably a manually operable device is positioned outside the plate member and coupled with the lockdown member for movement of the lockdown member and the outwardly extending teeth into and out of engagement with the cutouts of the plate member. 
     A resilient device preferably in the form of a coil spring, is positioned between the manually operable device and the plate member and arranged to bias the outwardly extending teeth of the lockdown member into engagement with the tooth-shaped cutouts of the plate member. 
     The tooth shaped cutouts in the plate member are generally triangular to match the cross-section of each of the outwardly extending teeth coupled to the pivot rod. The manually operable device is preferably a grip knob, and the coil spring is positioned between the grip knob and the plate member. In an alternative embodiment, the outermost dimension of the radially outwardly extending teeth is constant as measured along the length of the elongated member. 
     An adjustable regulator and lock device for a pivotally rotatable damper adapted for installation in an air duct is also disclosed, which comprises a pivot rod extending through the air duct and generally transverse to the direction of air flow, the pivot rod having the damper rotatably coupled thereto and being rotatably mounted on the air duct for rotation between open and closed positions of the damper. A plate member is mounted to the outside of the air duct and generally facing an outer surface portion of the air duct, the plate member having an opening through which the pivot rod extends. 
     A lockdown member is rotatably coupled to the pivot rod and has a plurality of engagement devices movable into and out of engagement with correspondingly positioned mating engagement devices associated with the plate member to selectively fix the rotational position of the damper. The lockdown member is manually rotatable by a grip knob rotatably coupled with the lockdown member and adapted to move the lockdown member longitudinally with respect to the plate member and the pivot rod, into and out of engagement with the mating engagement devices of the plate member. The lockdown member is biased toward an engaged locked position with the plate member by a resilient member positioned between the grip knob and the plate member. 
     A damper unit as described hereinabove is also disclosed in combination with sheet metal ductwork of an HVAC system or the like, having an air duct. The damper unit as described herein is incorporated by reference into this paragraph. 
     Ductwork for directing conditioned air in a predetermined direction, is also disclosed which combines at least a section of sheet metal ductwork having an air duct having a generally tubular configuration and a generally circular cross-section with a damper unit according to the invention. The description of the damper unit as set forth herein is incorporated by reference into this paragraph. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will be described with reference to the drawings, wherein: 
         FIG. 1  is a front, top and left side perspective view of a ductwork damper assembly incorporating an adjustable damper regulator and lock device according to the invention, for controlling the flow of conditioned air in an air duct of an HVAC system; 
         FIG. 2  is a front, top and left side perspective view of the present inventive adjustable damper regulator and lock device shown in  FIG. 1 , for adjusting and locking the damper blade of the damper assembly in a pre-determined angular position; 
         FIG. 3  is a partial cross-sectional view, taken along lines  3 - 3  of  FIG. 2 , of the adjustable damper regulator and lock device of  FIG. 2 , showing the device in the locked position to securely fix the damper angular orientation in a selected angular position; 
         FIG. 4  is a partial cross-sectional view, taken along lines  4 - 4  of  FIG. 3 , showing the star shaped adjusting device of the adjustable damper regulator and lockdown device of the invention in the locked position shown in  FIG. 3 ; 
         FIG. 5  is a partial cross-sectional view similar to  FIG. 4 , with the star shaped adjusting device moved manually to the “unlocked” position against the force of the coil spring, to facilitate pivotal movement of the damper blade to a predetermined selected angular orientation; 
         FIG. 6  is an enlarged view of a portion of  FIGS. 3 and 5 , illustrating the slightly rounded leading edges of the lockdown engaging teeth of the star-shaped adjusting device, which assist entry into the correspondingly configured star-shaped controlling engagement teeth of the opening in the lock plate, in the event of a slight mis-alignment between the teeth and the star-shaped opening in the lock plate, when adjusted by a user; 
         FIG. 7  is an enlarged top view of a portion of  FIG. 6 , illustrating the self-alignment feature of the lockdown device as the device is moved toward the locked position; 
         FIG. 8  is an enlarged portion of  FIG. 6 , showing the rotatable star-shaped lockdown engaging teeth in the engaged position in the corresponding star-shaped opening of the lock plate; 
         FIG. 9  is a top and left side perspective view of the adjustable damper regulator and lockdown device of the invention, with parts separated for illustrative purposes, showing the preferred star-shaped toothed lock device having a tapered configuration over its length; 
         FIG. 10  is a top and left side perspective view of an alternative embodiment of the invention, with parts separated for illustration purposes, showing the star-shaped toothed lockdown device having a constant outermost dimension over its entire length; 
         FIG. 11  is a top and left side perspective view of an alternative embodiment of the adjustable damper regulator and lockdown device of the invention, wherein the adjustment of the damper blade can be made using a tool such as a wrench having a square drive socket; and 
         FIG. 12  is a top and left side perspective view of yet another alternative embodiment of the invention, wherein a wrench-like lever device is permanently attached to the shaft of the damper regulator and lockdown device, and is utilized, when needed, to adjust the damper blade position according to the invention, said lever providing a ready indicator of the angular portion of the damper. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring initially to  FIG. 1 , there is illustrated a damper assembly  10  for a heating, ventilating and air conditioning (hereafter HVAC) system, incorporating an adjustable regulator and lock device  12  constructed according to the present invention. The damper assembly includes duct  14  having a generally circular configuration, on which damper blade  16  is pivotably mounted on suitable bushings  18  as shown. The bushings  18  can be of any known type, or of the type disclosed in my copending patent applications, including U.S. provisional application No. 61/573,679, filed Sep. 9, 2011, U.S. patent application Ser. No. 13/481,336, filed May 25, 2012 and International application no. PCT/US2012/054069, filed Sep. 7, 2012, the disclosures of which are incorporated herein by reference in their entirety and made a part of this application. 
     The damper blade  16  is in the form of a sheet metal plate which can be made of any of several materials, including metal, plastic, composite, ceramic or the like. Generally the damper blade  16  is made of sheet metal and has a circular configuration as shown, which generally matches the generally circular cross-section of duct  14  as is the case in most HVAC systems. The present invention can be used with HVAC systems and ductwork of all types. 
     The damper blade  16  is fixedly attached to pivot rod  20  for rotation with bearing-type bushings  18  between a fully closed position and a fully open position, in which the damper is oriented at an angle of about 90 degrees relative to the fully closed position, or generally in line with the longitudinal axis A-A of the ductwork  14 . Pivot rod  20  has a square cross-section to facilitate rotational coupling with damper blade  16 . 
     When conditioned air (i.e., cooled or heated) is to be fully directed through the damper assembly  10 , the damper blade  16  is fixed in the fully opened position. When only partial amounts of the conditioned air is to be directed through the damper assembly  10 , then position of the damper blade  16  can be adjusted and fixed at a predetermined angle relative to the longitudinal axis. When the damper blade  16  is intended to completely block the flow of conditioned air through the damper assembly  10 , then the damper blade  16  is moved to the closed position as shown in  FIG. 1 , and secured in that position by fasteners of various types. In general, when it is desired to block the conditioned air to a certain location (i.e., when the particular location is not in use), the damper blade is simply pivoted to the closed position and locked in place. 
     It can be fully appreciated that effective and efficient adjustment of such dampers ideally require that several conditions be met, the most significant of which include:
         1) ready access to the adjustment device;   2) multiplicity of angular damper positions available to the user;   3) stability of the adjustment device in any number of angular damper positions, whereby vibrations are avoided;   4) quick and positive adjustment capability; and   5) remote visual indicator of the angular orientation of the damper blade, which itself is usually not visible to the user.       

     Referring now to  FIGS. 1-9 , the structural and functional features of the adjustable regulator and lock device of the present invention are illustrated. The device  12  includes U-shaped bracket  22  of sheet metal, attached to the air duct of ductwork  14  by bent feet  24 ,  26  which can be attached to the ductwork in a known manner such as by spot welds or otherwise. The central section/plate  28  of U-shaped bracket  22  facing the outer surface of the air duct as shown, includes a generally circular star-shaped aperture  30  having a plurality of generally radially extending triangular shaped tooth shaped cutouts  31  positioned about the periphery of the opening  30  as best shown in  FIGS. 9 and 10 . Damper pivot rod  20  extends through the ductwork  14  and is pivotably supported on bearing-type bushings  18 ,  19  in perpendicular relation to the direction of air flow, as shown in  FIGS. 1, 3 and 5 . 
     As best seen in  FIG. 9 , pivotally rotatable plate  32  is attached to pivot rod  20  and has extending from one surface, a frusto-conical toothed lockdown member  44  having a plurality of radially extending tapered teeth  45  which correspond in number, dimension and shape to the tooth shaped cutouts  31  of the star-shaped opening in plate  28 , making it possible to shift the tapered lockdown member  44  into and out of locking engagement with the star-shaped aperture  30  of plate  28  after rotating it to any one of a number of relative angular orientations of the lockdown member (and correspondingly, the damper) with respect to the plate  28 . The tapered profile of toothed lockdown member  44  facilitates quick entry of teeth  45  into opening  30 , due to the progressively decreasing outermost dimensions of the teeth  45  as measured along the axis B-B of pivot. Accordingly, plate  32  can be longitudinally moved along axis B-B of pivot rod  20 , thereby moving lockdown member  44  into and out of engagement with plate  28 . When the tapered lockdown member  44  is moved out of engagement with opening  30  in plate  28 , plate  32  is free to rotate with damper blade  16  and pivot rod  20  to any of a number of angular positions corresponding to between a fully closed and a fully open damper position, respectively. When the tapered lockdown member  44  is shifted out of engagement with plate  28 , knob  40  may be rotated counterclockwise or clockwise between “damper open” and “damper closed” positions, respectively. 
     As shown, when lever  34  engages the right side plate  23  of bracket  22 , further movement is limited, and the damper is in the closed position. When the knob  40  is rotated until lever  34  engages the left side plate  21  of bracket  22 , further movement is limited, and the damper is in the fully open position, as indicted by the marking “open”. Rotation of the knob  40  in the clockwise direction will rotate the damper to other positions, as indicated by the markings, “half way” and “closed” in  FIGS. 2, 4 and 9 . 
     Circular shaped plate  32  having indicator lever  34  attached to, and extending radially therefrom, is movable along longitudinal axis B-B to positions whereby tapered lockdown member  44  can move into and out of engagement with the plate  28  to cause lockdown member  44  to engage with tooth shaped cutouts  31 , to select a suitable angular position for the damper blade  16 . The angular position of the damper is readily discernable to the user from the outside merely by observing the position of the lever arm  34 , which also acts as a limit stop when it engages with the U-shaped bracket  22  as shown in  FIG. 1 . 
     Hub  36  is preferably molded unitarily from plastic, or otherwise attached to control knob  40  as best shown in  FIGS. 3 and 9 . It can be appreciated that rotation of knob  40  will produce corresponding rotation of pivot rod  20  and damper blade  16  with bushings  18 , due to the square drive-type connection between square opening  42  in knob  40  and the same square cross-section of pivot rod  20 , which is complementary to square opening  42  in knob  40 . Plate  32  having indicator lever  34  extend radially therefrom is attached to damper shaft  20  for rotation therewith. 
     For the embodiment shown in  FIGS. 1-9 , the knob  40  is made of a suitable plastic material, with collar  38  also being made of plastic and being resiliently engaged with hub  36  by annular resilient leg  39  as best shown in  FIG. 3 . The plastic material may be nylon, polyester, polypropylene, ABS or any extrudable plastic material. 
     For applications subject to relatively extreme temperatures, the active components of the invention can be made of other suitable materials such as metal, ceramic, composites or the like, without departing from the scope of the invention. 
     Referring once again to the drawings, and in particular, to  FIGS. 1-9 , the toothed lockdown member  44  is retained in engagement with the star-shaped opening  30  in plate  28  by the force of resilient coil spring  46  positioned in engagement with plate  28  at one end, and with flat annular surface  37  of control knob  40  at the other end as best shown in  FIG. 3 . 
     When the lockdown member  44  is in engagement with plate  28  as shown in  FIG. 3 , the angular position of the damper blade is fixed by the force of coil spring  46  acting between plate  28  and knob  40  and by engagement of lockdown teeth  45  with mating tooth shaped cutouts  31  in plate  28 . 
     Referring now to  FIG. 5 , the release and pivot function of the inventive device is illustrated. As can be seen, release of tapered toothed member  44  is made by manually pushing knob  40  inwardly with force “F” against spring  46  to cause lockdown member  44  to exit opening  30  and clear plate  28  from behind. Tapered lockdown teeth  45  are now clear of control engaging tooth shaped cutouts  31  in plate  28 , which now permits the knob  40 , the pivot rod  20 , lever  34 , and damper blade  16  to be pivotally rotated to any of a number of selected angular positions between “open” and “closed”. In  FIG. 5 , for example, the damper blade  16  has been pivoted to the fully open position, as indicated by the position of lever  34 , which is now engaged with the left wall  21  of U-shaped bracket  22 . When the predetermined angular position of the damper blade  16  is reached (as visibly indicated by the position of lever  34 ), the force “F” is released by the user, and knob  40  is permitted to return to the original rest (and locked) position of  FIGS. 1 and 3 . At the same time, the lockdown teeth  45  of toothed member  44  re-enter the corresponding tooth shaped cutouts  31  of opening  30  in plate  28  at the new angular position, to firmly fix the new angular position of the damper blade  16 . 
     Referring now to  FIGS. 6 and 7 , one significant optional feature of the invention is illustrated. In particular, the leading edges  45   a  of the lockdown teeth  45  of toothed member  44  are slightly rounded as shown, to facilitate quick and smooth entry into the corresponding control engagement star-shaped tooth shaped cutouts  31  of opening  30  in plate  28 . As can be seen, the rounded tips  45   a  of teeth  45  will readily enter the tooth shaped cutouts  31  of opening  30  in plate  28  in the event the user rotates the teeth  45  of toothed member  44  to a position which is not in complete alignment with the tooth shaped cutouts  31  of the opening  30 . Such ready entry is particularly facilitated by the presence of the rounded tips of teeth  45 . This assist will result in quick entry of lockdown teeth  45  into star-shaped tooth shaped cutouts  31  of opening  30  of plate  28  of U-shaped bracket  22  as shown in  FIG. 8 . This action is also illustrated in  FIGS. 6 and 7 , where  FIG. 7  is a partial cross-sectional view taken along lines  7 - 7  of  FIG. 6 . 
     It can be seen that the present invention provides a number of advantages over prior art devices which are intended to adjust the angular position of a ductwork damper, and to lock the position of the damper in a selected angular orientation. 
     The present invention is easy to manufacture, and includes a relatively small number of components, given the relatively complex function and objective which it provides. Secondly, the invention provides quick and secure positioning of the angular position of the damper, by the distribution of the lockdown force over a substantial number of tooth shaped cutouts  31  extending over the entire periphery of the opening  30  in plate  28 . Considering the force of air flow against the damper blade in the closed position, this feature provides a clear advantage of the present invention in that the forces to retain the damper in position are distributed over a substantial number of teeth thereby promoting stability and minimizing vibrations. In addition, by the position of the indicator lever  34 , the invention provides a clear and ready observable indicator to the user of the angular position of the damper, which is generally hidden from sight. Optimally, markings indicating the angular position of the damper blade  16  can be provided on plate  28  as shown in  FIGS. 2, 4, 9 and 10 , which correspond to the positions of the lever arm  34 . By selecting the number of teeth on tapered member  44  and in circular opening  30 , the angular spacing between positions can be varied, depending upon the needs of a particular application. Finally, it can be appreciated that adjustment of the damper position can also be made by manually gripping and rotating lever arm  34 . 
     An Alternative Embodiment 
     While the embodiment shown in  FIGS. 1-9  preferably incorporates a toothed lockdown member  44  having a tapered side elevational profile as shown, an alternative embodiment 50 is shown in  FIG. 10  which incorporates a toothed lockdown member  52  which includes a plurality of radially extending teeth  51  similar to the previous embodiment, but which teeth have a constant outermost dimension over their entire length as measured along the axis B-B of pivot rod  20 . U-shaped bracket  53  includes central section/plate  56 , right side plate  57  and left side plate  55 . In all other respects, this alternative embodiment is structured identically, and functions in the same manner as the previous embodiment. For example, the opening  54  of plate  56  has a plurality of tooth shaped cutouts  49  positioned about the periphery of the opening  54 . 
     While the embodiment of  FIG. 10  does not provide the ease of entry into the opening  54  of plate  56  as with the tapered embodiment of  FIGS. 1-9 , it nevertheless functions well, requiring the user to “feel” the path of the toothed engagement member between the teeth  51  of the toothed lockdown member  52  and the opening  54  in plate  56 . 
     Referring now  FIG. 11 , there is shown an embodiment of the present invention, wherein the adjustment of the damper blade can be made using a tool such as a wrench having a square drive socket  58  to firmly grip the pivot rod of square cross section. Generally such pivot rods are approximately ⅜ inch square. Accordingly, a square drive socket wrench will be appropriate. 
     Referring now to  FIG. 12 , there is shown yet another alternative embodiment of the invention, wherein a wrench-like lever  60  is permanently attached to the damper pivot rod for ready adjustment as and when needed. 
     LIST OF REFERENCE NUMERALS 
     
         
         
           
               10  Damper Assembly 
               12  Adjustable Regulator and Lock Device 
               14  Duct 
               16  Damper Blade 
               18 ,  19  Bushings 
               20  Damper Pivot Rod or Shaft 
               21  Left Side Plate 
               22  U-Shaped Bracket 
               23  Right Side Plate 
               24 ,  26  Bent Feet 
               28  Central Section of U-Shaped Bracket  22   
               29  Left Wall of U-Shaped Bracket 
               30  Generally Circular Star-Shaped Aperture in Central Section  28   
               31  Control Engaging Teeth in Central Section  28   
               32  Pivotable Circular Plate 
               34  Indicator Lever 
               36  Hub 
               38  Collar 
               39  Annular Resilient Legs 
               40  Knob 
               42  Square Opening in Knob  40   
               44  Frusto-Conical Tapered Toothed Member Having Tapered Lockdown Teeth 
               45  Tapered Lockdown Teeth 
               45   a  Rounded Leading Edges of Tapered Lockdown Teeth 
               46  Coil Spring to Bias Elongated Member in Locked Position 
               49  Engaging Controlling Teeth in Plate  56   
               50  Alternative Embodiment having Elongated Toothed Member of Constant Diametral Dimension 
               51  Teeth 
               52  Toothed Lockdown Member of Constant Diametral Dimension 
               53  U-Shaped Bracket in Alternative Embodiment 
               54  Generally Circular Star-Shaped Opening in Plate  56   
               55  Left Side Plate of Bracket  53   
               56  Central Plate Having Generally Circular Star-Shaped Opening  54 , with Teeth  49  to Receive Toothed Lockdown Member  52   
               57  Right Side Plate of Bracket  55   
               58  Square Drive Socket Wrench 
               60  Wrench-Like Lever Permanently Attached to Device