Patent Publication Number: US-11047494-B2

Title: Air admittance valve preventing mephitis overflow

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims all benefits accruing under 35 U.S.C. § 119 from Taiwanese Patent Application No. 104200490, filed on Jan. 13, 2015, in the Taiwanese Intellectual Property Office, disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an air admittance valve preventing mephitis (noxious gas) overflow, and particularly relates to the field of using an air intake apparatus. 
     Description of Related Art 
     According to the prior art air intake pipe structure shown in  FIG. 5 , which is formed of a pipe body  50 , air intake channeling functions are performed for all kinds of apparatuses via connection of apparatuses with the pipe body  50 . Also in  FIG. 6 , a structure formed of a pipe body  50  and a pipe cover body  60  is shown, wherein a net surface  61  is located on top of said pipe cover body  60 . The pipe cover body  60  covers the top of the pipe body  50 , so that air is introduced into the pipe body  50  through the net surface  61  of the pipe cover body  60 . Moreover, although the apparatus coupled through the pipe body  50  performs air intake channeling functions for all kinds of apparatuses. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an embodiment of air admittance valve. 
         FIG. 2  shows a cross-section, along with other parts, of an embodiment of the main body in an embodiment of the air admittance valve. 
         FIG. 3  shows a cross-section of an embodiment of an air admittance valve. 
         FIG. 4  shows actuation of an embodiment of a valve body in an embodiment of an air admittance valve. 
         FIG. 5  shows an air intake pipe according to the prior art. 
         FIG. 6  shows an air intake pipe and pipe cover according to the prior art. 
     
    
    
     DETAILED DESCRIPTION 
     It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures and components have not been described in detail so as not to obscure the related relevant feature being described. Also, the description is not to be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale and the proportions of certain parts have been exaggerated to better illustrate details and features of the present disclosure. 
     Several definitions that apply throughout this disclosure will now be presented. 
     The term “coupled” is defined as coupled, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently coupled or releasably coupled. The term “outside” refers to a region that is beyond the outermost confines of a physical object. The term “inside” indicates that at least a portion of a region is partially contained within a boundary formed by the object. The term “substantially” is defined to be essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising,” when utilized, means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in the so-described combination, group, series and the like. The term “vehicle” includes motor vehicles (e.g. motorcycles, cars, trucks, buses), railed vehicles (e.g. trains, trams), watercraft (e.g. ships, boats), aircraft and spacecraft. 
     The present invention is related to the prior art problems of insufficient prevention functionality and sealing instability in air intake pipe structures, and therefore provides an air admittance valve preventing mephitis overflow. One embodiment provides an air admittance valve preventing mephitis overflow comprising of a main body  10 , an external lid body  20 , a sealing valve group  30 , and a connecting pipe body  40 . Plurality of position-fixing lugs  100  can extend from outside the main body  10 , and an outer connecting part located outside the main body&#39;s  10  lower side. In some embodiments, an outer connecting part is an external thread. An entry guide base  102  is located inside the main body  10 . An air entry guide  102 A is defined by the entry guide base  102  and a blocking protrusion  102 B is located at the other side of the entry guide base  102 . One or more pivot supports  102 C can be located between the blocking protrusion  102 B and the air entry guide  102 A. In some embodiments, there are two pivot supports  102 C. The external lid body  20  inner side comprises a side groove  21 , and the sealing valve group  30  comprises a sealing valve body  31 , a valve seat  32 , and a flexible member  33 . A cover body piece  310  is located on a first side of the sealing valve body  31 , and a pivot flange and a recess  312  are located on a second side of the sealing valve body  31 . A pivot  311 A is located in the pivot housing  311  and the two pivot supports  102 C. The friction between the pivot  311 A, the pivot housing  311  and/or pivots supports  102  can help define the sensitivity of the air admittance valve. The less the friction, the less force required to overcome the friction and more precise the actuation of the valve can be based upon the other elements (e.g. the flexible member  33 ). A valve seat  32  is located in the main body recess  312 . A flexible member  33  is located in the containing recess. A connecting head  41  is located on the upper side of the connecting pipe body  40 . An inner connecting part  410  is located inside of the connecting head  41 . In some embodiments, the inner connecting part  410  is a locking thread that will correspond with the outer connecting part  101 . A pipe body piece  42  can be located at the lower part of the connecting pipe body  40 . The external lid body  20  covers part of the main body  10 . In some embodiments, a plurality of the side grooves  21 , located inside the external lid body  20 , abut the plurality of position-fixing lugs  100  located around the outside of the main body. One or more pivot housings  311  are located on the sealing valve body  31 . In some embodiments, the two pivot supports  102 C are located on the entry guide base  102 . The valve seat  32 , located in the main body recess, helps create a seal when abutting the cover body piece  310 . In one embodiment, one end of the flexible member  33  is located inside the recess  312  of the sealing valve body  31 , and a second end is restricted by the blocking protrusion  102 B. An outer connecting part  101  is coupled to an inner connecting part  410 . When a sufficient minimum pressure drop is transmitted by the pipe body piece, the cover body piece  310  is actuated, so that fresh air is introduced into the air entry guide  102 A through the gap formed between the main body  10  and the external lid body  20 . In some embodiments, the sufficient minimum pressure drop is about 0.009 psi (Pounds per Square Inch). In other embodiments, the sufficient minimum pressure drop can be higher (e.g. 0.01 psi up to 3 psi and higher). Air is then introduced into the pipe body piece  42  and the apparatus that is coupled to the pipe body piece  402 . When the pipe body piece  402  and the ambient pressure are in balance, or below the minimum pressure drop, the cover body piece  310  abuts the valve seat  32 . The flexible member  33 , located in the recess  312 , biases the cover body piece  310  against the valve seat  32 , but allows for opening when the minimal pressure drop is present. Thus overflow of mephitis is prevented by effective sealing and the advantages of good prevention functionality and good sealing stability are obtained. 
       FIGS. 1 and 2  show exploded views of an embodiment of an air admittance valve. A main body  10 , in which plurality of position-fixing lugs  100  are located circumferentially outside of the main body  10 , and an outer connecting part  101  is located circumferentially around the outside the main body  10 . In some embodiments, the outer connecting part  101  is an external locking thread. An air entry guide  102 A is located at one side of the entry guide base  102 , and a blocking protrusion  102 B is located at the other side of the entry guide base  102 . The two pivot supports  102 C are located opposite to each other between the blocking protrusion  102 B and the air entry guide  102 A. 
     In some embodiments, the external lid body  20  comprises plurality of side grooves  21  that are located inside the external lid body  20 . The external lid body  20  is located the main body  10 , and the plurality of position-fixing lugs  100  are arranged at least partially in the side groove  21 . In other embodiments, the position-fixing lugs  100  extend from the main body  10 . In some embodies, there are no position fixing lugs  100 , only a passage way to allow air to enter the air entry guide  102  is required. In some embodiments, there is no external lid body  20 . 
     In some embodiments, a sealing valve group  30  comprises a sealing valve body  31 , a valve seat  32 , and a flexible member  33 . A cover body piece  310  is located at the first side of the sealing valve body  31  and a recess  312  is defined by the second side of the sealing valve body  31 . A pivot  311 A passes through the pivot housing  311 , which is located between the cover body piece  310  and the recess  312 . The valve seat  32  is located in the main body recess. The flexible member  33  is at least partially located within the recess  312 , and the pivot housing  311  is located on the sealing valve body  31 . Two pivot supports  102 C can be located on the entry guide base  102 . The valve seat  32  abuts the cover body piece  310 , when in the closed position. In some embodiments, the valve seat  32  is partially located in a main body recess. In other embodiments, the valve seat  32  is not in a recess and secured to the main body  10 . The flexible member  33  is located in the recess  312  and, in some embodiments, abuts the blocking protrusion  102 B. In some embodiments the blocking protrusion  102 B is substantially conical shaped. When present, the blocking protrusion can be of any shape that allows it to help keep the flexible member  33  in line with the recess  312   
     A connecting pipe body  40  comprises a connecting head  41  and a pipe body piece  42 . In some embodiments, an inner connecting part  410  is located inside the pipe wall of the connecting head  41 , and/or the inner connecting part  410  is an internal locking thread. 
       FIGS. 3 to 4  show an assembled embodiment of an air admittance valve. The external lid body  20  is coupled to the main body  10 . The side groove  21  is defined by the inside of the external lid body  20  and receives one of the plurality of position-fixing lugs  100  located around the outside of the main body  10 . A pivot housing  311  is located on the sealing valve body  31 . Two pivot supports  102 C are located on the entry guide base  102 . When closed, the valve seat  32  abuts the cover body piece  310 . A first end of the flexible member  33  is located in the containing recess  312  of the sealing valve body  31 , and in some embodiments, the other end is restricted by the blocking protrusion  102 B. In other embodiments, the flexible member second end abuts the entry guide base  102 . The main body  10  is coupled to the connecting pipe body  40 . In some embodiments, an outer connecting part  101  will be coupled to an inner connecting part  410 , located inside the connecting head  41 . When a sufficient pressure drop occurs in the pipe body piece  42 , cover body piece  310  will rotate into an open state, so that air is introduced into the air entry guide  102 A from the gap formed between the main body  10  and the external lid body  20 . Air will then flow into the pipe body piece  42  and into the apparatus that is coupled with the pipe body piece  42 . The flexible member  33  biases the cover body piece  310  to abut the valve seat  32  and close the air entry guide  102 A. Thus overflow of mephitis is prevented by effective sealing and the advantages of good prevention functionality and good sealing stability are obtained. 
     The rotational nature of the sealing valve group  30  provides for balancing when used in situations where there is movement of the apparatus. In some embodiments, this balancing is critical to the proper functioning of the sealing valve group  30 . This movement can occur with vehicles. In some embodiments, the pivot  311 A is located substantially along the center of gravity of the sealing valve body  31 , such that the sealing valve body  31  is balanced about the pivot. This is very useful in an area in which the apparatus would move. For example, while located in a vehicle, such as a recreational vehicle, a bump is hit, and the apparatus is thrusted upwards and back down. During such a movement, the momentum on both sides of the sealing valve body  31  will help prevent accidental opening thus preventing mephitis overflow. The momentum will be balanced on both sides. This balancing of the sealing valve body  31  will also help lessen the amount, if any, openings in response to asymmetrical movements of the apparatus. Also since there is little opening and closing, there will be less rattling when compared to other air admittance valves of the prior art. In some embodiments, the vehicles require the valve body  31  to open at very low pressure drops due to the design of the plumbing systems. In some embodiments the pressure drop required to open the valve body  31  is 0.008 psi. In some embodiments it can be even lower. 
     The balancing of the sealing valve body  31  will also allow for the flexible member  33  to more precisely determine the opening pressure required for the sealing valve body  31  to actuate. Increasing the strength of the flexible member, will increase the pressure drop required to actuate the sealing valve body, and vice versa. Thus one would be able to easily adjust the pressure drop required by adjusting the flexible member  33  that is used. 
     One problem that often can occur is that the adhesion between the valve and the valve seat, and when talking about low pressure conditions, the adhesion can cause difficulty in opening the valve. Thus the materials of sealing valve body and the valve seat  32  should be of such a combination as to minimize the adhesion between them. In some embodiments, the valve seat  32  is made of silicone with a low durometer. Other materials that provide for a quality seal can also be used. 
     The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including, the full extent established by the broad general meaning of the terms used in the claims.