Patent Publication Number: US-6712335-B1

Title: Fluid damper

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a novel and useful fluid damper. 
     Dampers are used to control fluid such as air in edifices and other facilities. Airflow control is acutely necessary in clean structures, often requiring dampers in the ceiling and floor. 
     In the past, dampers have followed two basic designs a “butterfly” and a “split butterfly” arrangement. Both designs utilize a central axis in which blades are extended outwardly and lies perpendicular to the flow of air. Unfortunately, these prior designs suffer from deficiencies in that positioning of the blades or “set” is often lost due to the flow of air against the blades. Thus, the control of airflow via the prior art designs is difficult to achieve. In addition, noise is easily generated by the “butterfly” and “split butterfly” designs. These problems are exacerbated by flow rates of air required by clean room structures. 
     Prior structures have been proposed to control the flow of air in a ventilation conduit. For example, U.S. Pat. Nos. 916,484 and Des. 347,471 show ventilators and dampers of conventional configuration. 
     U.S. Pat. Nos. 3,070,346, 3,095,178, and 4,817,508 describe dampers having veins which are rotatable or pivotal within a conduit and include reinforcements to aid in their stability. 
     U.S. Pat. No. 4,188,862 describes a register assembly in which louvers are rotated about a central hub to control airflow. 
     U.S. Pat. No. 4,094,492 shows a variable “iris” orifice flow control in which a plurality of blades or flanges open and close in the same manner as a camera shutter. 
     U.S. Pat. No. 3,068,891 illustrates a flow regulator in which a series of plates are rotated about a central shaft and are cantilevered from the same to control airflow. 
     U.S. Pat. No. 6,010,113 teaches a damper with fanning blades which are rotatably attached to a central hub. The peripheral ends of the blades fit into a groove to guide the same in a rotary manner. 
     U.S. Pat. No. 2,235,731 shows a damper in which angularly disposed damper elements arrange to fit on fixed elements to open and close an opening as a damper element is moved through arcuate slots. 
     A damper which exhibits precise control in high fluid flow conditions would be a notable advance in the mechanical arts. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention a novel and useful damper is herein provided. 
     The damper of the present invention utilizes a frame having a base which may be constructed in an endless configuration such as one that is circular, annular, rectangular, and the like. The base includes a wall portion which extends outwardly from the base and includes an end which is also an endless member. The frame defines an aperture or opening generally used for the passage of air in a fluid or air circulation system such as a conduit. The frame may be fastened to a conduit or filter system by conventional means. 
     A stepped edge portion is located at the end of the wall portion and is positioned to at least partially circumvent the aperture. The stepped edge portion may be constructed separately and attached to the wall portion, or formed integrally therewith. The frame, and its components described above, may be manufactured from any rigid or semi-rigid material such as metal, ceramics, plastics, and the like. 
     A plurality of flanges or blades are also employed in the present invention. At least a first and a second flange are used and are positioned in overlying relationship to one another. Thus, the first flange is movable relative to the second flange in a sliding relationship. An appropriate number of flanges are employed to close or occlude the aperture formed by the frame when the flange is fanned out or spread across the aperture in such sliding arrangement. The flanges are supported by a central hub which may be turned using any mechanical means, and may be locally or remotely operated. Of course, the central hub may be turned or rotated using automatic controls known in the art. 
     Means is also provided in the present invention for moving the first and second flanges relative to one another in an overriding relationship. Such means may be manual or take the form of a motor known in the art. The motor may transmit such rotary motion via the shaft and a gearing arrangement of conventional configuration. The plurality of flanges ride on the step edge portion of the frame during overriding movement relative to one another. The stepped edge portion serves to guide and to uniformly spread the plurality of flanges across the aperture during the process of closing or occluding of the aperture. Such movement may be accomplished by using a pair of wheels, a first wheel pivotally linked to the first flange and a second wheel rotatable relative to a bracket supported by the frame. The second wheel may serve as an extension of the shaft that is movable manually by a motor, remotely or locally. The wheels may take the form of gears to more positively control the movement of the first flange relative to the aperture of the frame. 
     Linking means is also provided for permitting the first flange to engage the second flange and to pull the same in a rotational manner about the central pivot. Such linking means may include a tab formed on the first flange and a slot constructed on the second flange such that the tab locates within the slot and may travel therewithin. Of course, movement of the second flange occurs when the tab of the first flange contacts an edge of the slot. Moreover, such linking means may be used between successive flanges or blades of any number to permit the same to rotate about a central pivot located above the aperture of the frame. 
     It may be apparent that a novel and useful fluid damper has hereinabove been described. 
     It is therefore an object of the present invention to provide a fluid damper which very accurately controls the flow of air in a ventilation system. 
     Another object of the present invention is to provide a fluid damper which is not susceptible to loss of a “set” due to the flow of fluid or air in a ventilation system. 
     Another object of the present invention is to provide a fluid damper which greatly eliminates noise associated with dampers of the prior art. 
     A further object of the present invention is to provide a fluid damper which exhibits great durability and may be used in air circulation systems having a high rate of flow. 
     Yet another object of the present invention is to provide a fluid damper system which is easily adaptable to clean room structures requiring precise control of airflow. 
     Another object of the present invention is to provide a fluid damper which very accurately controls the flow of fluid in a circulation system and is easy to manufacture, having a minimum of moving parts. 
     Yet another object of the present invention is to provide a fluid damper which greatly reduces the leakage of fluid through the damper when the damper is in its occluded configuration. 
     The invention possesses other objects and advantages especially as concerns particular characteristics and features thereof which will become apparent as the specification continues. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     FIG. 1 is a top plan view of the damper of the present invention shown in its open position. 
     FIG. 2 is a side elevational view of the central pivoting portion causing rotation of the primary flange about an axis. 
     FIG. 3 is a bottom plan view of the damper of the present invention in its open position. 
     FIG. 4 is a bottom plan view of the damper of the present invention in a partially occluded position. 
     FIG. 5 is a bottom plan view of the damper of the present invention in a completely occluded position. 
     FIG. 6 is a broken side elevational view showing the linking means and step guiding edge portion employed during fanning of the multiplicity of flanges. 
     FIG. 7 is a partially broken top plan view depicting the linking means shown in FIG.  6 . 
     FIG. 8 is a sectional view taken along line  8 — 8  of FIG.  7 . 
     FIG. 9 is a sectional view taken along line  9 — 9  of FIG.  3 . 
     FIG. 10 is a sectional view taken along line  10 — 10  of FIG.  5 . 
    
    
     For a better understanding of the invention reference is made to the following detailed description of the preferred embodiments thereof which should be taken in conjunction with the prior described drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION 
     Various aspects of the present invention will evolve from the following detailed description of the preferred embodiments thereof which may be fully understood by reference to the herein above-delineated drawings. 
     The preferred embodiment of the invention is shown in the drawings by reference character  10 . Damper  10  includes as one of its elements a frame  12 . Frame  12  possesses a base  14  and includes a wall portion  16  which extends outwardly therefrom. Frame  12  forms an aperture or opening  18  through the same which is generally used to direct the passage of fluids such as air, directional arrows  20  and  22 , FIG.  1 . Frame  12  may be constructed of metallic material, although other materials such as composites plastics, and the like would suffice in this regard. Frame  12  is mounted within a ventilation system adjacent a filter or within a duct by conventional means such as fasteners, clamps, and the like. Opening  24 , FIG. 2, may be employed to accept a fastener in this regard. Wall portion  16  includes an end  26  which substantially surrounds aperture  18 . A stepped edge portion  28  is located at end  26  of wall portion  16 . As depicted in FIG. 2, stepped edge portion  28  includes distinct levels or flattened areas  30 ,  32 , and  34 . Stepped edge portion  28  may be formed integrally with wall portion  16  or separately and attached to wall portion  26  by any suitable means such as rivets, fasteners, glues welding, and the like. 
     A plurality of flanges or blades  36  are positioned in overlying relationship with one another. FIG. 1 represents the stacked arrangement of plurality of plates  36 . For example, blade  38  which is the prime moving blade, is shown as a one-piece element having flared portions  40  and  42  at its extremities. Each blade of plurality of blades  36  includes this general configuration. Plurality of blades  36  stacked upon one another are capable of fanning outwardly in about pivot pin  44 . Pivot pin  44  lies along axis  46  which is centrally located in aperture  18 . FIG. 2 also illustrates flanges  48 ,  50 , and  52  which are stacked in that order beneath flange  38 . It should be noted that flange  38  is overall shorter in length than the next succeeding flange  48  which is shorter than the next succeeding flange  50 , and so on, to provide the stacking arrangement depicted in FIG.  1 . In general, flange  38  is slidably movable relative to flange  48  and so forth through succeeding flanges to create a fan-like expansion over aperture  18 , which will be described in greater detail as the specification continues. 
     Pivot pin  44  along axis  46  is supported by bracket  54  which spans frame  12 . Bracket  54  is held in place by any suitable means such as rivets, fasteners, and the like. Pivot pin  44  serves as the central focal place for the expansion and contraction of flanges  36 . 
     Means  56  is also found in the present invention for moving flange  38  relative to flange  48  and successive flanges stacked one upon the other. Means  56  may take the form of a shaft  58  which may be manually turned or rotated by a motor in a conventional manner. Directional arrow  60  on FIG. 1 indicates the rotational movement of shaft  58  along axis  62 , also shown in FIG.  2 . Shaft  58  is fixed to rotatable wheel or gear  64  having a mitered surface  66 . Gear  64 , fixed to pivot pin  44 , meshingly engages gear or wheel  68  which rotates according to directional arrow  70  about axis  46 . Of course, other structures may be employed to turn pivot pin  44  and plurality of flanges  36 , such as a flexible rotatable cable, and the like. Prime moving flange  38  is fixed to neck  72  of gear  68  by the use of welding, fasteners, springs, clamps, and any other conventional structure in this regard. Needless to say, the rotation of gear  68  also turns flange  38  about axis  46  such that the flared portions  40  and  42  of flange  38  sweep across aperture  18 . Flange  38  also rides on stepped edge portion  28 , specifically level  30 , depicted in FIG.  2 . In addition, flange  48  rides on level  32  and is prevented from further rotational movement about axis  46  by rise  74 . Rise  76  stops the further rotational movement of flange  50  along level  34  and so on. Thus, plurality of flanges  36  create an evenly spaced fan-like structure across aperture  18  when in the occluded configuration, FIG.  5 . 
     FIGS. 4-5 indicate the successive movements of plurality of flanges  38  about axis  46 . Flange  78  represents a fixed member which serves as an anchor to prevent further movement of plurality of flanges  36  when they are in the configuration depicted in FIG.  5 . Fixed flange  78  is connected to bracket  54  by a pin or tab  80 . Another pin or tab  82  holds flange  78  to bracket  54  in the vicinity of shaft  58 . 
     Although flange  38  comprises the prime-moving flange in the system of the present invention, linking means  84 , FIGS. 6-8 permits the engagement of flange  38  with flange  48 . In turn, flange  48  engages flange  50 , and so on through successive plurality of flanges  36 . Other than prime moving flange  38  and fixed flange  78 , the remaining plurality of flanges  36  may be deemed slave flanges since they are essentially pulled through linking means  84  by the motivation of flange  38 . Directional arrows  86  indicate the back and forth movement of plurality of flanges  36  through linking means  84 . 
     Viewing now flange  38  on FIGS. 6-8, it may be observed that a tab  88  fits within a slot  90  formed by an arch  92  which may be integrally formed with flange  48  or connected thereto. It should be noted that tab  88  is free to move within slot  90  to the extremities afforded by arch  92 . FIG. 6 represents the extreme positioning of flange  38  to the left in solid lines and the extreme positioning of flange  38  to the right in broken lines. Likewise, flange  48  includes a tab  94  which lies within the slot  96  formed by arch  98  of flange  50 . Thus, through the use of tabs and slots associated with successive plurality of flanges  36 , prime moving flange  38  opens and closes plurality of flanges  36  as shown in FIGS. 3-5. 
     Viewing now FIG. 9, plurality of flanges  36  are stacked in the open configuration of FIG.  3 . Fixed flange  78  is depicted in detail and possesses a fence  108  which serves as a stop for plurality of flanges  36 . As plurality of flanges  36  fan out across aperture  18  during occlusion, directional arrow  110 , flared portion  42  of prime moving flange  38  overrides flange  48 . FIG. 10 represents of occluded position of damper  10  of FIG. 5 where fence  108  serves to seal flared portion  40  of flange  38 . Such sealing achieves the low leakage characteristics of damper  10  when plurality of flanges are in the occluded configuration of FIG.  5 . 
     In operation, the user utilizes manual or motor means to turn shaft  58 , locally or remotely, which, in turn, rotates gear  64  about axis  62 . Gear  64  engaging gear  68  turns gear  68  and prime moving blade  38  attached thereto. Such action will spread or collapse plurality of flanges  36  to open or close aperture  18  formed by frame  12  according to FIGS. 3-5. Temporary adhesion between individual flanges of plurality of flanges  36  will not prevent the spreading of plurality of flanges since they are interconnected through linking means  84 . Directional arrows  100  and  102  on FIG. 3 indicates the free movement of air through damper  10  on the side of damper  10  shown in FIG.  1  and indicated by directional arrows  20  and  22 . Fluid or air passing through damper  10  will tend to press plurality of flanges  36  upon frame  12 , specifically stepped end portion  28 , as the direction of flow or air through damper  10  is along axis  46 . The opening of aperture  18  may be adjusted by the turning of shaft  58  to a position desired by the user which controls the flow of air through aperture  18  and the ventilation system associated with damper  10 . FIG. 5 indicates the damper  10  has been completely closed blocking air from passing in either direction through damper  10 . Pairs of directional arrows  104  and  106  are shown partially in phantom to indicate that air is pressing on the opposite side of that depicted in FIG.  5  and cannot pass through damper  10  in its closed position. Linking means  84  permits the opening and closing of damper  10  by the motivation of prime moving flange  38 . Fixed flange  78  anchors the further movement of plurality of flanges  36  about axis  46  when damper  10  is in the is position depicted in FIG. 3 or FIG. 5, completely open or completely closed. 
     While in the foregoing, embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of skill in the art that numerous changes may be made in such detail without departing from the spirit and principles of the invention.