Abstract:
A pressure relief valve provided for installation in an opening in a motor vehicle body. In particular, the valve is configured to allow a volume of air to flow therethrough substantially equivalent to the volume of air permitted to flow through the opening if the valve was not installed therein. Furthermore, the valve is formed of flexible material for ease of installation into an opening that is smaller than the interior portion of pressure relief valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application No. 60/288,550, filed May 3, 2001. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a car cabin exhaust vent, and in particular to a pressure relief valve for vehicle ventilation of the cabin section. 
   BACKGROUND OF THE INVENTION 
   It is generally known in the art to provide a pressure relief valve for the cabin of many motor vehicles. In particular, larger vehicles include a plurality of pressure relief valves for allowing movement of air through the cabin or to relieve pressure during a sudden increase of pressure in the cabin. Furthermore, the valves work to allow a free flow of air for ventilation systems to allow for efficient cooling and heating of the cabin section. 
   Generally, the prior art valves include valve flaps that rest on a grille system or other such structure. The grille system, while leaving areas open for the flow of air, also obstructs the flow of air through the valve. Furthermore, prior art valves and vent systems generally comprise a rigid polymer structure that is closely sized to the aperture which must be produced within the vehicle body. Very small tolerances in the size of the aperture are permitted. 
   As such, prior art valves typically are no larger than the aperture in the body of the vehicle. Furthermore, prior art valve systems are unable to reach the optimal amount of air flow, that being the amount allowed by an empty or unrestricted aperture. In particular, prior art valve systems comprise structure that obstructs the optimum air flow through the aperture produced within the vehicle body. Therefore, while generally adequate in keeping rain, debris, and other materials from entering the vehicle body, such valve systems are less than ideally efficient in venting air outside the vehicle body. 
   SUMMARY OF THE INVENTION 
   The present invention of a pressure relief valve or air exhauster, comprises a body portion and a flap for closing the valve when no air is flowing therethrough. The entire air exhauster is formed as a fully flexible member. Unlike prior art, pressure relief valves, this flexibility allows portions of the air exhauster to be sized larger than the aperture of the vehicle body into which the air exhauster is to be mounted. 
   Furthermore, the air exhauster of the present invention is configured to permit air flow therethrough that is generally equivalent to the amount of air flow passing through an unobstructed aperture. This is accomplished in part by utilizing a generally funnel shape for the interior portion of the valve body. In addition, the air exhauster of the present invention does not require, but may include, a grille system to support the valve flaps. 
   One advantage of the air exhauster of the present invention is the ease of installation into an opening or aperture in a body of the vehicle created by the fully flexible nature of the exhauster. The flexible frame exhauster may be quickly and easily installed into the opening formed in the vehicle. 
   A further advantage of the present invention is the possibility of a unitarily formed exhauster. The valve flaps are unitarily formed with the valve body through hinge sections. This allows for a singular production piece not requiring further assembly after production of the component of parts. However, it is to be understood that the valve flaps may be manufactured separately and installed onto the valve body while remaining in the scope of the invention. 
   A still further advantage of the present invention is its self-sealing design. As part of its unitary design, the exhauster valve body includes a flange portion for sealing the exhauster valve with the vehicle body. 
   Still another advantage of the present invention is its funnel type configuration in which the inlet side has a greater cross-sectional dimension than the exhausting side. This helps ensure maximum air flow through the valve. 
   A further advantage of the present invention is that it comprises minimal structure or portions which obstruct the free flow of air being exhausted from the vehicle. 
   Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
       FIG. 1  is a perspective view of a pressure relief valve of the present invention taken from the inlet side after the exhauster is removed from the injection molding machine; 
       FIG. 2  is a perspective view of the pressure relief valve of  FIG. 1  taken from the opposite end of the exhauster; 
       FIG. 3  is a perspective view of the pressure relief valve of  FIG. 1 , taken from the outlet side of the valve; 
       FIG. 4  is a perspective view of the pressure relief valve, like that shown in  FIG. 1  except that the flaps of the exhauster are in the operative position; 
       FIG. 5  is an environmental view of the pressure relief valve of  FIG. 4 , installed in an exemplary motor vehicle according to the present invention; and 
       FIG. 6  is a perspective view of the pressure relief valve according to a second embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
   With reference to  FIGS. 1 and 2 , the general structure of the presently disclosed invention for a car cabin pressure exhauster is illustrated. The pressure relief exhauster or pressure relief valve is generally shown at  10 . In particular, the pressure relief valve  10  includes a sealing flange  12  and a body flange  14  with a plurality of walls  18 ,  20 ,  22 , and  24  affixed to and extending generally transversely from the body flange  14 , vertical from and affixed to the body flange  14 . Furthermore, the plurality of walls  18 ,  20 ,  22 ,  24  extend obliquely from the body flange  14  and define voids  25   a ,  25   b  through which air may flow. 
   By way of illustration and not to be limiting, the presently illustrated pressure relief valve  10  includes a first end wall  18  and a second end wall  24  wherein the first end wall is of a greater height than the second end wall  24 . This creates a slope to the top of the pressure relief valve  10  from the first end wall  18  towards the second end wall  24 . Furthermore, the lateral walls  20 ,  22  also slope from the first end wall  18  end to the second end wall  24  end. At the junction of the lateral walls  22 ,  20  with the body flange  14  are engaging members  16 . The engaging members  16  engage the sheet metal of a car vehicle&#39;s body (as shown in  FIG. 5 ) into which the pressure relief valve  10  is installed. Therefore, the flange  12  not only seals pressure relief valve  10 , but also prevents the pressure relief valve  10  from moving further into the vehicle while the engaging members  16  retain the valve against the vehicle body. 
   On the tops of the lateral walls  20 ,  22  are flaps  40  affixed thereto. The flaps  40  have a first side  42   a  and a second side  42   b . The flaps  40  are affixed to the lateral walls  20 ,  22  with living hinge regions  44   a ,  44   b . However, it is to be understood that the hinges  44   a ,  44   b  need not be integrally formed with the lateral walls  20 ,  22 . In particular, a separate portion including the flaps  40  and hinges  44   a ,  44   b  may be affixed to the lateral walls  20 ,  22 . The flaps  40  extend the general length of the lateral walls  20 ,  22  and the hinge regions  44   a  and  44   b  extend the full length of the flap  40  and top of the lateral wall. 
   The first end wall  18  terminates in a first upper region  26  which includes a lip  27  which overhangs the voids  25   a ,  25   b  whereas the second end wall  24  terminates in a second upper region  28  which includes a second lip  29  overhanging voids  25   a ,  25   b . Furthermore, running medially between the first end wall  18  and the second end wall  24  is a third lip  30 . With continuing reference to  FIGS. 1 and 2  and further reference to  FIG. 3 , the lips  27  and  30  include an under lip or seating areas  27   a  and  30   a . It is also to be understood that, although not shown, lip  29  also includes an under lip or seating area  29   a . The respective under lip regions  27   a ,  29   a  and  30   a  provide a seat for the flaps  40 . 
   With reference  FIGS. 1–3 , the pressure relief valve  10  is illustrated in the state in which the pressure relief valve  10  is removed from the molding process. When the pressure relief valve  10  is formed in the production process, the flaps  40  extend generally outwardly in the same general direction as the lateral walls  20 ,  22 . This molding configuration imbues the flaps  40  and the hinge regions  44   a ,  44   b  with an inherent biasing effect in the upward direction and outward direction. Prior to installation, however, of the pressure relief valve  10 , into a vehicle body, the flaps  40  are pressed past lips  27 ,  29 , and  30  and into the voids  25   a ,  25   b . Thereafter, by virtue of the inherent biasing effect of the hinge regions  44   a  and  44   b , the flaps  40  attempt to return to their generally outward positions and are stopped by the seating areas  27   a ,  29   a , and  30   a . In addition, the inherent biasing effect of the hinge regions  44   a  and  44   b  may be increased or decreased depending upon the thickness of the hinge regions  44   a  and  44   b . In a preferred embodiment of the present invention, the flaps  40  of the pressure relief valve  10  will be of a thickness between 0.20 mm and 2.0 mm. In a more preferred embodiment, the thickness of the flaps  40  will be between 0.30 mm and 1.0 mm. The hinge regions  44   a  and  44   b  will have a preferred thickness of between 0.10 mm and 0.90 mm and a more preferred thickness of between 0.20 mm and 0.75 mm. Therefore, the desired biasing force of the hinge regions  44   a  and  44   b  may be customized for the particular use to which the pressure relief valve will be placed. 
   With reference to  FIG. 4 , a pressure relief valve  10  is shown with one of the flaps  40  in the seated or closed position. The bottom of the flap  42   b  may be seen through the bottom of the pressure relief valve  10 . The edges of the flap  40  engage the under lip areas  27   a ,  29   a ,  30   a  and seal the flap  40  closing the pressure relief valve  10 . When installed in a motor vehicle (see generally  FIG. 5 ), air will flow from within the cabin toward the pressure relief valve  10  engaging the tops  42   a  of the flaps  40 . When the air pressure within the cabin reaches a pressure greater than the inherent biasing force of the hinge regions  44   a  and  44   b , the flaps  40  move into the voids  25   a ,  25   b . When the flaps  40  have been moved into the voids  25   a  and  25   b , air may then flow from the cabin through the pressure relief valve  10  in the direction of Arrow A (see  FIG. 1 ). In this way, the pressure within the cabin may be equalized with the outside and air may flow easily through the cabin. It is to be understood that the inherent biasing of the hinge regions  44   a ,  44   b  keep the flaps  40  seated against the seating areas  27   a ,  29   a  and  30   a  when the air pressure is equivalent on both sides of the valve. 
   When closed, moisture, debris or air may not move back through the pressure relief valve  10  into the vehicle cabin. Due to the seating arrangement of the flaps  40 , when air attempts to flow from outside the vehicle body into the cabin, the seated flaps  40  do not allow air to flow in that direction. Therefore, the pressure relief valve is understood to be a one way valve. 
   With reference to  FIG. 5 , an environmental view of an installed pressure relief valve  10 , according to the present invention, is illustrated. An automobile  50  generally includes a front portion  52  and a rear portion  54 . In particular, the rear portion  54  includes the pressure relief valve  10  installed in a lower portion thereof. The pressure relief valve  10  is typically installed in a body panel of the automobile  50  generally covered by a fascia or a bumper  56  portion. A bumper  56   a  is also installed on the front portion of the vehicle which would generally mirror the rear portion  54  of the vehicle. 
   It is to be understood that the cabin of the automobile, in particular a sedan or the like, is generally bounded by the top of the car  58 , an internal floor pan  60 , a forward firewall  62 , rear seats and a back wall of the cabin  64 , and on the sides by a plurality of doors  66  and windows  68 . It is to be further understood that this is exemplary only. In particular, vehicles such as SUV&#39;s may not have a cabin bounded by a rear seat. Rather, in large SUV&#39;s and station wagons, the back of the passenger cabin may be bounded by a back or hatch door. Such back or hatch door are themselves bounded by vertical pillars which engage the door in the closed position. 
   The portions of the vehicle bounding the passenger cabin are not impervious to air flow, therefore the pressure relief valve  10  may still act as a valve for the cabin area of the automobile  50  even though it is not physically connected to the vehicle cabin. Therefore, once the pressure relief valve  10  is installed in the vehicle  50 , any change in cabin pressure may be relieved by the pressure relief valve  10  even though the pressure relief valve  10  is not in direct contact with the passenger cabin due to the fact that it is in fluid contact with the passenger cabin. It is to be further understood that the presently disclosed pressure relief valve  10  may be installed in other areas of the automobile so that it has contact with the outside and the passenger cabin, such as in the wheel wells. As a further example, a pressure relief valve  10  may be placed beneath the front bumper  56   a  in the same way as it is placed under the rear body of bumper  56 . Furthermore, the pressure relief valve  10  may be installed in the pillars of an SUV (see discussion above). In addition, the biasing hinges  44   a  and  44   b  hold the flaps  40  in the seated position even when the pressure relief valve  10  is mounted horizontally. Therefore, the pressure relief valve  10  may also be mounted in the roof  58  of a vehicle  50  or the top of a wheel well. 
   With general reference to all the Figures and particular reference to  FIG. 1 , further details of the pressure relief valve  10  are disclosed. The preferred material of the pressure relief valve  10  is a flexible polymer, a thermoplastic elastomer, or preferably a thermoplastic vulcanite (TPV). One particular TPV is SX70 manufactured by Solvay Engineered Polymers. Such materials or similar materials have a general flexibility feature allowing the finished product to be fully flexible. Furthermore, it is preferred that the entire pressure relief valve  10  be unitarily formed of a singular material temporarily deformed. The entire pressure relief valve  10  may be folded or otherwise deformed into a smaller dimension before insertion into a motor vehicle  50  body. In particular, the end walls  18  and  24  will include structures to assist the deforming of the pressure relief valve  10 . In particular, valley  70  will facilitate the collapse of the side walls  20  and  22  towards the third lip  30 . Additionally, reinforcement sections  72  will transfer forces applied to the side walls  20  and  22  towards the valley  70  and further assist the directed deformability of the pressure relief valve  10 . In this way, the pressure relief valve  10  may be quickly and easily installed into an aperture in a vehicle  50 . Therefore, the vehicle body aperture, into which the pressure relief valve  10  is installed, may be of a dimension much smaller than the actual size ingress side of the pressure relief valve  10 . However, the dimensions of the aperture in the vehicle body will be of the same general dimensions as the body flange  14 . 
   The preferred embodiment of the valve  10  is configured such that the walls  18 ,  20 ,  22 , and  24  extend in a non-perpendicular manner. More particularly, each of the walls  18 ,  20 ,  22  and  24  extend obliquely and will form an acute angle with the body flange  14 . In this way, vehicle cabin side of the voids  25   a ,  25   b  will have an overall dimension greater than or equal to the aperture in the motor vehicle  50 , wherein such aperture is defined to be no greater than the inner dimensions of the flange  12 . In this way, due to the venturii effect of the sloped walls of the pressure relief valve  10 , the air flow through the valve  10  will be equal or nearly equal to that of an open aperture in the motor vehicle  50 . 
   With reference to  FIG. 6  a pressure relief valve  100 , according to a second embodiment of the present invention, is illustrated, wherein like reference numerals reference like portions as described above in reference to the first embodiment. The pressure relief valve  100  includes a first valve flap  102  and a second valve flap  104 . The first valve flap  102  includes a bottom side  106  and a topside (not illustrated). The second flap  104  includes a top side  108  and a bottom side (not illustrated). A distal edge  110  of the first flap  102  extends the length of the first flap  102 . A distal edge  112  of the second flap  104  also extends the length of the second flap  104 . According to the second embodiment, the leading edges  110  and  112  have a profile other than a line or planar profile. For example, the leading edge  110  may include a radius of curvature of any appropriate degree. The leading edge  112  of the second flap  104  may also include a radius of curvature of a substantially corresponding degree. This radius of curvature, relative to the flaps  102  and  104 , may either be concave or convex. It is also understood that the flap portions  102  and  104  will have the substantially same radius of curvature along the entire width of the flaps  102  and  104 . Thus, the entire flap may have a radius of curvature. 
   When the flaps  102  and  104  have a particular radius of curvature the first lip  114 , second lip  116  and third lip  118  all have dimensions which substantially match the shape of the flaps  102  and  104 . In particular, this means that the third lip  118  will have a radius of curvature substantially similar to the radius of curvature of the flaps  102  and  104 . In this way, when the flaps  102  and  104  are seated on the third lip  118  the flaps form a substantial seal and close the pressure relief valve  100 . 
   The radius of curvature, or any other appropriate shape, of the flaps  102  and  104  is used to selectively determine the amount of pressure required to move the flaps  102  and  104  from the seated or closed position, that is when the flaps engage the lips  114  through  118 , to the open position. For example, one particular radius of curvature may require approximately one pound per square foot of pressure to move the flaps  102  and  104  to an open position. A different radius of curvature, however, may require at least three pounds of pressure per square foot to move the flaps  102  and  104  to the open position. It will be understood, however, that any particular pressure may be tuned by altering the shapes of the flaps  102  and  104 . Therefore, the pressure relief valve  100  may be tuned or customized by varying the shapes or profiles of the flaps  102  and  104  to specifically account the amount of pressure required to move the flaps  102  and  104  from the closed or seated position to the open position to allow air to flow through the pressure relief valve  100 . 
   The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.