Abstract:
A wind powered rotatable vent includes an annular rotatable louvered panel axially rotatable about a shaft and an impeller disposed in spaced underlying relationship with respect to the rotatable louvered panel and rotatably secured to the shaft. A fixed collar underlies at least a portion of the rotatable louvered panel and a brace which is rotatably secured to the shaft has first arms secured to an upper portion of the rotatable louvered panel and second arms secured to a lower portion thereof. The collar and rotatable louvered panel define a passageway for flow of air therethrough. The rotatable louvered panel is structured to rotate responsive to wind impinging thereon and responsive to air flowing upwardly through the impeller in the passageway.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a rotatable vent having an annular rotatable louvered panel and an underlying rotatable impeller both of which are rotatably positioned with respect to a fixed shaft. More specifically, it relates to such a louvered panel which cooperates with a fixed collar to define an air flow passageway while resisting undesired entry of precipitation into the building to which it is secured. 
   2. Description of the Prior Art 
   It has been known to provide various types of turbine and other vents which are secured to roof portions or other portions of a building for purposes of efficiently exhausting air from the building and discharging the same to the surrounding environment. 
   In some such structures a motor or solar energy source of power is employed to energize a rotating fan element which has suitable blades for exhausting air from a region. The rotating fan which is fixedly secured to a shaft and exhausted through a cover member may be provided with a series of louvers. 
   It has also been known to provide turbines which are freely rotatable by wind currents to rotate an exhaust assembly and draw air up through a collar and outwardly through a passageway. See, for example, U.S. Pat. No. 4,641,571. 
   U.S. Pat. No. 5,779,539 discloses a static venting system which had a plurality of nested louvered members providing a static venting system for discharge of air therethrough. 
   One of the disadvantages of prior art systems is the need to have a source of energy to power the same or the need to rely on air flow through a static system. 
   Another disadvantage of prior art systems has been the large generally dome shaped aesthetically unpleasant appearance of the louvered element which projects a substantial distance above the roof or other structure. 
   A further disadvantage of prior systems involves collar members which are so closely placed to the rotating louver members that under certain conditions undesired contact therebetween produced an unpleasant noise during relative rotation. 
   Also lacking in prior art systems are structures of suitable strength as to withstand extended use under varying weather conditions, including wind loading. 
   In spite of the foregoing there remains a very real and substantial need for an improved rotatable vent which is devoid of prior inadequacies. 
   SUMMARY OF THE INVENTION 
   The present invention has met the hereinbefore described needs. 
   The invention provides a rotatable vent having an annular rotatable louvered panel and an underlying spaced impeller both of which are rotatably secured to a fixed shaft. A fixed collar having at least a portion underlying the rotatable louvered panel is provided and a brace rotatably secured to the shaft has first arms secured to an upper portion of the rotatable louvered panel and second arms secured to a lower portion of the rotatable louvered panel. 
   The louvers are preferably generally vertically oriented and the impeller blades are slanted so as to enhance the efficiency of exhaust when the impeller is rotated responsive to the louver being rotated by external wind to establish flow of air upwardly through the passageway defined between by the fixed collar and the rotatable louvered panel. 
   A suitable cap is provided over a top louver cover so as to resist undesired entry of precipitation and airborne foreign matter into the passageway other than through open louvers. Preferred weather shields are provided in the lower cap member to further resist such undesired entry of precipitation and foreign matter. 
   It is an object of the present invention to provide an efficient rotating vent which rotates responsive to exterior wind without requiring another source of power or due to rising warm air within the building, such as in an attic or both. 
   It is a further object of the present invention to provide such a rotating vent which avoids undesired noises present in certain prior art systems. 
   It is yet another object of the present invention to provide a low profile rotating vent that which is suitable for positioning on roofs or other building parts. 
   It is yet another object of the present invention to provide such construction which is structurally reinforced so as to resist undesired failure of the rotating vent. 
   It is yet another object of the present invention to provide such rotating vents which are structured to efficiently and quietly remove heat and moisture from the interior of a roof structure. 
   It is a further object of the present invention to provide a durable, economical and aesthetically pleasing rotating vent. 
   It is yet another object of the invention to provide a wind powered, fan assisted rotating vent wherein the source of power to operate the vent will be external with the airstream moving across the exterior of the vent to rotate the fan and establish upward flow of air in order to exhaust the same through the vent. 
   These and other objects of the invention will be more fully understood from the following detailed description of the invention on reference to the illustrations appended hereto. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partially schematic cross-sectional illustration of a form of rotatable vent of the present invention. 
       FIG. 2  is a partially schematic cross-sectional illustration of a modified form of rotatable vent of the present invention. 
       FIG. 3  is an exploded view of the rotatable vent of FIG.  2 . 
       FIG. 4  is a partially schematic elevational view showing the bracing members of a form of rotatable vent of the present invention. 
       FIG. 5  is a top plan view of the bracing members of FIG.  4 . 
     FIG.  6 ( a ) is a fragmented elevational view of a portion of the rotatable louvered vent of the present invention. 
     FIG.  6 ( b ) is a schematic illustration showing the angles of the louver elements with only a few being illustrated. 
       FIGS. 7 and 8  are, respectively, a plan and elevational view of the upper cover and brace connector of the rotating vent of the present invention. 
       FIGS. 9 and 10  are, respectively, a plan view and elevational view of a lower cover of the present invention. 
       FIGS. 11 and 12  are, respectively, a top plan and elevational view of a weathershield of a rotatable vent of the present invention. 
       FIG. 13  is a cross-sectional view of an impeller of the present invention. 
       FIG. 14  is a top plan view of the impeller of FIG.  13 . 
       FIG. 15  is a top plan view of the fixed collar brace of the present invention. 
       FIG. 16  is an elevational view of the collar brace of the present invention. 
       FIG. 17  is a top plan view of a top cover of the present invention. 
       FIG. 18  is an elevational view of the top cover of FIG.  17 . 
       FIG. 19  is a top plan view of a base member of the present invention. 
       FIG. 20  is a right-side elevational view of the base of FIG.  19 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring in greater detail to  FIG. 1 , there is shown a form of rotatable vent of the present invention. In this embodiment a rotatable louvered panel  2  is of generally annular configuration and has a plurality of generally vertically oriented louver elements positioned circumferentially therearound to permit radial flow of air thereby. A fixed shaft  8  has its lower end secured to a base  10  and is surrounded by a fixed collar  12  which is secured to shaft  8  by means of a hub  14  which is fixedly secured to the shaft  8 . A brace member  16  has upwardly extending arms such as  18  and  20  which terminate in flanges  24 ,  26 , respectively, which are secured to an interior surface of an upper portion of the fixed collar  12 . The upper portion of the rotatable louvered panel has an overlying cover  30  which cooperates with a weather cap  32  which is secured to shaft  8  by rivets (not shown) or by other suitable fasteners adjacent shaft end  40 . A plurality of first bracing arms such as  42 ,  44 , for example, extend upwardly and outwardly and have respective flange members  46 ,  48  secured to panel cover  30 . The weathercap  32  has an annular angularly downwardly projecting annular flange  50  in order to resist undesired entry of precipitation and foreign matter into the space  52  between the weathercap  32  and the panel top cover  30 . A plurality of second arms such as  60 ,  62  extend generally downwardly and outwardly and terminate, respectively, in flanges  64 ,  66  which are secured to a bottom panel cover  70 . The inner portions of the arms such as  44 ,  46 ,  60 ,  62  are connected to a hub  72  which, in the form shown, is rotatably connected to shaft  8  by bearings  80 ,  82 . 
   Disposed in spaced underlying relationship with respect to the rotatable louvered panel is an impeller or fan  90  which has a plurality of individual blade members  92  which are angularly offset with respect to the vertical. Warm air within the building may cause rotation of impeller  90 . The inner portion of the rotatable louvered panel  2  and a fixed collar  12  define a generally vertical passageway  94  for flow of air therethrough. 
   In the form shown in  FIGS. 1 through 3  the louvered panel  2  has louvers which are preferably generally parallel to each other and oriented in the same direction. The individual louvers of louvered panel  2  as shown in  FIGS. 1 and 3  will have an angular orientation such that the left edge will be closer to the geometric center of the panel than the right edge. This results in the louver being angled forwardly from left to right in the figures. Wind impinging on the exterior of the louvered panel  2  will establish clockwise rotation of the louvered panel which in cooperation with the impeller  90  blade  92  orientation will urge air upwardly through passageway  94  and out of the building. If desired, the cooperating louvers and impeller blades may both be provided in the reverse orientation to provide the same effect with rotation of the louvered panel in a counterclockwise direction. 
   Air moving upwardly through passageway  94  will impinge on the underside of top cover  36  and will flow outward to exit the vent. It should be noted that lower weathershield  100  is of annular configuration and terminates in a generally upwardly and outwardly extending flange  101  so as to resist undesired entry of precipitation and foreign matter into the passageway  94 . The weathershield  100  may be integrally formed with bottom panel cover  20 , if desired. 
   One of the advantages of the present invention is the elimination of some of the prior art large upwardly projecting, aesthetically unappealing spherical louvered shapes. The present invention provides a low profile. It is preferred that the rotating louvered panel have an external diameter D which is about 2 to 5 times the height H of the rotatable louvered panel and, most preferably, about 2.5 to 3.75 times the height H. For example, the diameter D may be about 15 to 18 inches and the height H may be about 4 to 6 inches. It is also preferred that the external diameter D of the rotatable louvered panel  2  be about 1.25 to 1.75 times the exterior diameter X of the fixed collar  12 . 
   It will be appreciated that the rotatable vent of the present invention may have components made of any structurally suitable durable material which will permit economical manufacture and efficient functioning. In general, it is preferred that the parts exposed to the weather be made of a suitable metal, such as aluminum. The rotating louvered panel  2  and cap  36  and fixed collar  12 , for example, may be made of aluminum. Other components which are disposed on the interior, such as the brace member  16 , arms  43 ,  44 ,  46 ,  48  and impeller  92 , may be made of a suitable resinous plastic material. 
   In installing the vent on a roof or in an exterior wall or in other desired location, a hole of suitable diameter which, generally, will be the same as diameter X of fixed collar  12  will be made in the building and the base  10  will be secured to the region surrounding the opening as by screws or other fasteners. Suitable flashing may be provided thereover. 
   Referring to  FIG. 2 , there is shown a modified form of the invention. In this embodiment the collar  12 ′ is modified so as to be adjustable depending upon the orientation of the building portion to which it would be secured. For example, either the embodiment of  FIG. 1  or  2  could be employed readily on a flat roof structure or a structure wherein a flat base on the collar such as base  10  on collar  12 ′ could be employed. On the other hand, the collar  12 ′ may be provided with greater height Y than the collar  12  shown in  FIG. 1  for certain uses and could be provided with a line  112  for severance where it would be desired to have the bottom of the collar  12 ′ angularly oriented. 
   Referring to  FIG. 3 , an exploded version of the embodiments of  FIGS. 1 and 2  is shown, with the collar  12 ′ of  FIG. 2  being employed. As shown, the rotatable louvered panel  2  has a top louver panel cover  30  and an overlying cap  36  having an underlying weather cap  32  which terminates in a downwardly directed annular flange  50 . If desired, cover  30  and cap  36  may be provided as a unitary structure. 
   The bottom panel cover  70  is preferably annular and has an underlying weathershield  100  which terminates in a generally upwardly and outwardly directed flange  102 . The weathershield  100  may be integrally formed with cover  70 . The brace member has a hub  72  which is rotatably secured to the shaft  8  and bearings (not shown in this view) and has a plurality of upwardly and generally outwardly projecting first arms  42 ,  44 ,  43 ,  45  which are secured to the top louvered panel cover  30  by any suitable means such as suitable mechanical fasteners. A plurality of second arms  60 ,  62  are secured to the hub  72  at a lower level than the first arms  42 ,  44 ,  43 ,  45  and are preferably of an equal number. The underlying impeller  90  which may be molded from a suitable resinous plastic material such as an engineering grade polymer having the desired strength and molded surface finish. It is rotatably secured to the shaft  8  by means of hub  120  (FIGS.  1  and  2 ). The cap member  39  and top  40  secure the assembly to the bracing member. Underlying the impeller is a bushing member  124  which is operatively associated with a push nut  126 . A lower bracing member  16  has a plurality of generally upwardly and outwardly projecting arms such as  18 ,  20  which terminate in upper flanges  24 ,  26  respectively, and may be secured to the inner surface of annular wall  140  of collars  12  or  12 ′. 
   The base  10  preferably has a radial extent greater than diameter D of the rotatable louvered panel  2  and has an upwardly projecting portion  146  which is adapted to fit within the lower end of collar  12  or  12 ′ with suitable mechanical fasteners such as rivets  150 ,  152 ,  156  as shown, for example, in  FIG. 2 , fixedly securing the collars  12 ,  12 ′ to the base  10 . 
     FIGS. 4 and 5  show details of the brace provided on the interior of rotatable louvered panel  2 . As shown, the hub  72  has upper and lower bearing receiving recesses  160 ,  162 . The upward flanges have openings  164 ,  166  for passage of mechanical fasteners therethrough in order to secure the upper brace arms such as  44 ,  46  to the top louver panel cover  30 . Similarly, arms  60 ,  62  terminate in flanges  64 ,  66  which have openings  170 ,  172  for passage of mechanical fasteners therethrough and into bottom louver panel cover  70 . 
   As shown in the plan view of  FIG. 5  in the form illustrated a brace has, four upper arms  42 ,  44 ,  180 ,  182  and four lower arms  60 ,  62 ,  186 ,  188 . 
   Referring to FIGS.  6 ( a ) and ( b ), the rotatable louvered panel  2  has a plurality of outwardly open louvers such as  175 ,  177  which, as shown in FIG.  6 ( b ), have an included angle A which, preferably, would be about 20 to 45 degrees so as to permit efficient use of wind impinging on the same to establish axial rotation of the rotatable louvered member  2 . For certain sizes, it is preferred that the louvered member have a diameter D of about 15 to 18 inches and a height H of about 4 to 6 inches with the low profile being a preferred feature of the invention. 
   The upper cover  30 , as shown in  FIGS. 7 and 8 , has a generally circular periphery and is solid. The brace arms such as  42 ,  44 ,  180 ,  182  are secured to the undersurface of the same. As shown in  FIGS. 9 and 10 , the lower cover  70  is annular and has a central opening  190  through which air may flow. Integral or separate peripheral weathershields may be provided for both covers  30 ,  70 . 
   As shown in  FIGS. 11 and 12 , the weatherproofing lower cover  100  is annular and defines a central opening  192  with an upwardly and outwardly projecting edge  196  so as to resist undesired entry of moisture and foreign material into the passageway. 
   As shown in  FIGS. 13 and 14 , the impeller has the hub  120  and a plurality of axially biased fan blades  92 ,  200 ,  202 ,  204 ,  206 ,  208 ,  210 ,  212 ,  214 ,  216 ,  218 ,  222 . 
     FIGS. 15 and 16  show the bracing element  14  for supporting the fixed collar  12 ,  12 ′. In the form shown it has four arms  18 ,  19 ,  20 ,  21  which extend upwardly and terminate in flanges  24 ,  26 , respectively, as well as flanges  229  and  231  on arms  19 ,  20 , respectively. These serve to provide a method of securement by suitable mechanical fasteners (not shown) to the interior of the fixed collars  12 ,  12 ′. Shaft  8  is secured within opening  236 . 
     FIGS. 17 and 18  show details of the top cover  36  with the underlying weathershield  32  and its downwardly and outwardly projecting edge  50 . If desired, the weathershield  32  may be integrally formed with top cover  36 . 
   As shown in  FIGS. 19 and 20 , the base member  10  has an outer portion  260  which will be employed to secure the vent to the building adjacent to the building opening and has an upwardly projecting portion  146  which will extend into the lower portion of fixed collar  121 ,  12 ′ and be secured thereto by mechanical fasteners such as rivets or screws  150 ,  152 ,  156  (FIG.  2 ). 
   It will be appreciated, therefore, that the present invention provides an improved wind or heat powered, low profile efficient rotatable ventilator which eliminates numerous problems of the prior art. The structure is economical to manufacture, easy to install, relatively silent in operation and does not require an independent source of power such as motors or solar panels. It is structurally reinforced so as to provide for efficient functioning and durability. 
   Whereas particular embodiments of the invention have been described herein for purposes of illustration it will be evident to those skilled in the art that numerous variations of the details may be made without departing from the invention as set forth in the appended claims.