Abstract:
A valve for sealing a carburetor inlet of a first diameter, includes a valve element having a curved surface for sealing the inlet opening, and a through hole of substantially the first diameter extending through the valve element, and a translation mechanism for rotating the valve element between a first position wherein the curved surface completely seals the opening and a second position wherein the through hole aligns with the inlet allowing a free flow into the carburetor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     The present invention claims priority to U.S. provisional patent application Ser. No. 60/658,999 filed on Mar. 4, 2005. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention is in the field of the automotive industry and pertains particularly the area of carburetor devices for reducing emissions, and pertains more particularly to devices and methods for preventing gasoline fumes from leaving a carburetor when the associated vehicle is stalled.  
         [0004]     2. Discussion of the State of the Art  
         [0005]     It is well known that vehicle exhaust emissions from internal combustion engines and fumes from raw gasoline and other combustible fuels are a source of pollution and environmental concern. Regulations exist and are continually enhanced and upgraded by various governmental sources, from local to national level.  
         [0006]     One area of growing concern is the area of evaporation of raw fuel, such as gasoline, from vehicle fuel systems. These emissions can be either from the storage tanks used for carrying fuel with a vehicle, or from fuel delivery systems used to deliver fuel to a carburetor device for mixing with air and providing to a an internal combustion engine. In the latter case, when a vehicle is in use, air is typically drawn from outside into a carburetor and mixed with fuel, such as gasoline. The flow of air into the carburetor in this instance effectively blocks back streaming of fuel vapor from the carburetor into the surrounding air. When the same vehicle is stopped, however, and the engine is off, raw fuel still in the carburetor will typically evaporate and back-stream from the carburetor into the local environment. The present invention deals with this back streaming, and the invention taught in one embodiment described below effectively ends back-streaming of fuel under these circumstances.  
       SUMMARY OF THE INVENTION  
       [0007]     A valve for sealing a carburetor inlet of a first diameter is provided and includes a valve element having a curved surface for sealing the inlet opening, and a through hole of substantially the first diameter extending through the valve element, and a translation mechanism for rotating the valve element between a first position wherein the curved surface completely seals the opening and a second position wherein the through hole aligns with the inlet allowing a free flow into the carburetor. In one embodiment, the valve element is molded of a polymer material. In another embodiment, the valve element is cast from a metal.  
         [0008]     In a preferred embodiment, the through hole is tapered out from the first diameter to form a second diameter at the valve end opposite the first diameter. Also in a preferred embodiment, the valve further includes a pair of diametrically opposed shaft extensions for facilitating intercommunication between the valve element and the translation mechanism. In one embodiment, the translation mechanism includes a solenoid and a linkage connecting a rotable shaft on the solenoid to a shaft extension of the valve element.  
         [0009]     According to another aspect of the present invention an air filter device is provided and includes a base plate, a filter housing, and a valve for sealing a carburetor inlet of a first diameter, the valve including a valve element having a curved surface for sealing the inlet opening, and a through hole of substantially the first diameter extending through the valve element and a translation mechanism for rotating the valve element between a first position wherein the curved surface completely seals the opening and a second position wherein the through hole aligns with the inlet allowing a free flow into the carburetor. In one embodiment, the air filter device has a dome feature for providing interior space for the valve to operate.  
         [0010]     According to another aspect of the invention, a method is provided for preventing backflow of fuel vapor from an inlet opening of a first diameter in a carburetor. The method includes steps of (a) fashioning a valve element having a curved surface for sealing the inlet opening, and a through hole of substantially the first diameter extending through the valve element, (b) mounting the valve element rotably so that rotation to a first position causes the curved surface to block the inlet, and rotation to a second position aligns the through hole with the inlet, and (c) rotating the valve element to the first position to prevent backflow of fuel, and to the second position to allow air to flow into the inlet.  
         [0011]     In one aspect, in step (a), the valve element is molded from a polymer material. In another aspect, in step (a), the valve element is cast from a metal. In one preferred aspect, in step (a), the through hole is tapered out from the first diameter to form a second diameter at the opposing side the through hole. Also in a preferred aspect, in step (b), the valve element includes diametrically opposed shaft extensions protruding there from, the extensions functioning as mounting arms and the rotation is about the axis formed by the shaft extensions. In one embodiment, in step (c), rotating of the valve element occurs to the first position when the engine is not running and to the second position when the engine is started.  
         [0012]     According to another aspect of the invention, a valve assembly connected to a carburetion system is provided. The valve assembly includes a housing having at least one outlet opening of a first diameter leading to the carburetion system, a valve, the valve including a valve element having a curved surface for sealing the outlet opening, and a through hole of substantially the first diameter extending through the valve element, and a translation mechanism for rotating the valve element between a first position wherein the curved surface completely seals the opening and a second position wherein the through hole aligns with the outlet allowing a free flow toward the carburetion system.  
         [0013]     In one embodiment, the housing is fashioned of aluminum or a polymer material. In a preferred embodiment, the through hole is tapered out from the first diameter to form a second diameter at the valve end opposite the first diameter. In one embodiment, the valve assembly further includes an inlet opening connected via flexible hose to an air filtration device. In a preferred embodiment, an elongated hose connects the outlet opening on the valve assembly to an inlet opening on the carburetion system. In preferred embodiments, the translation mechanism includes a solenoid and a linkage connecting a rotable shaft on the solenoid to a shaft extension of the valve element. In a preferred embodiment where there is connection to an air filtration device, the valve assembly is disposed between the carburetion system and the air filtration device, the components connected together by flexible hose forming a carburetor air intake system that is valve-controlled to prevent backflow of vapors from the carburetor into the valve assembly. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0014]      FIG. 1A  is a front view of an anti-back-streaming valve for a carburetion system according to an embodiment of the present invention.  
         [0015]      FIG. 1B  is a sectioned view of the valve of  FIG. 1A  taken generally along the section line AA.  
         [0016]      FIG. 1C  is an elevation view of a carburetion system enhanced with the anti-back streaming valve of  FIG. 1A  and  FIG. 1B  in vertical position during active air intake according to an embodiment of the present invention.  
         [0017]      FIG. 1D  is an elevation view of the system of  FIG. 1C  illustrating the anti-back streaming valve rotated to prevent back streaming of fuel according to an embodiment of the present invention.  
         [0018]      FIG. 2  is a perspective view of the system of  FIG. 1D  with the air canister, filter and valve removed to illustrated the mounting brackets and the carburetor inlet for clarity.  
         [0019]      FIG. 3  is a perspective view of the system of  FIG. 1D  with the air canister and filter removed illustrating the anti-back streaming valve mounted and components for driving the valve according to an embodiment of the present invention.  
         [0020]      FIG. 4  is an elevation view of a carburetion system enhanced with the anti-backstreaming valve of  FIG. 1A  and  FIG. 1B  according to another embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0021]      FIG. 1A  is a front view of an anti-back-streaming valve  103  for a carburetion system according to an embodiment of the present invention. Valve  103  may be molded from a suitably dense fuel and additive resistant polymer like nylon or Delran. In one embodiment, valve  103  may be cast of aluminum, brass, or other suitable metals that are corrosion resistant and that may exhibit a smooth surface finish, illustrated herein as surface  301  after casting and polishing so as to enable sealing along that surface, which is substantially spherical in a preferred embodiment of the invention.  
         [0022]     Valve  103  has an opening  302  provided there through and adapted as a valve opening for enabling intake of air into a carburetion system. Opening  302  is larger in diameter at one end of valve  103  than at the opposite end forming a conical shape functioning as a venturi whereby the larger diameter portion of opening  302  faces away from the carburetor. In one embodiment, opening  302  has a peripheral chamfer  307  provided at one end of the opening, however, this is not specifically required in order to practice the present invention. In one embodiment, valve  103  has shaft extensions  303  (one on each opposite side) provided thereon. Shaft extensions  303  are diametrically opposed sharing the same axis and extend substantially perpendicular from surface  301  to a position suitable for mounting in a bracket-type mounting arrangement described later in this specification. Extensions  303  may be formed contiguously with valve  103  in molding or casting depending at least in part of cost considerations and structural design considerations. Shaft extensions  303  protrude out from surface  301  of valve  103  but do not extend into opening  302 .  
         [0023]      FIG. 1B  is a sectioned view of valve  103  of  FIG. 1A  taken generally along the section line AA. Valve  103  is illustrated in section in this view to better illustrate opening  302  as formed there through. Opening  302  has an approximate 7-degree venturi angle projected inward from the major diameter edge of the opening. Other angles may be used in place of a 7-degree angle without departing from the spirit and scope of the present invention. The mentioned angle of inward taper is just an exemplary angle for producing a desired venturi effect for air entering a carburetion system enhanced with valve  103 . An axis  306  defines the substantial centerline of opening  302 . It is noted herein that with respect to an intake port of a carburetion system, valve  103  is uniquely caused to rotate such that opening  302  no longer communicates air into the carburetion system and surface  301  functions as a sealing agent over the intake port. More detail about operation of valve  103  is provided further below.  
         [0024]     The overall major diameter of valve  103  may vary widely without departing from the spirit and scope of the present invention. In a preferred embodiment, the size of valve  103  will depend, at least in part, on the size of a port on a carburetion system that will be enhanced by the valve in accordance with the present invention. Similarly, the dimensions of opening  302  may also vary accordingly.  
         [0025]      FIG. 1C  is an elevation view of a carburetion system enhanced with anti-back streaming valve  103  of  FIG. 1A  and  FIG. 1B  cause to assume a vertical position during active air intake according to an embodiment of the present invention. The carburetion system illustrated herein includes a fuel carburetion device, or carburetor  101 . Carburetor  101  may be any type of carburetion device such as are known in the art including single barrel, two-barrel, or four barrel type devices. Carburetor  101  may exhibit many different physical features, forms, and shapes without departing from the spirit and scope of the present invention. The inventor logically illustrates carburetor  101  as a block for simplicity and clarity. The only requirement of carburetor  101  is that it has at least one port that may be blocked by the valve of the present invention. Carburetors with more than one port may be equipped with more than one valve  103  accordingly.  
         [0026]     Carburetor  101  has a fuel/air intake port  102 , which extends vertically up from the surface of carburetor  101  through a base, illustrated herein as base  106 , of an air filter container or canister  104 . Container  104  may be typical of any type of canister that may contain an air filter whereby the combination is fitted over a carburetion port or ports of a carburetion system for the purpose of insuring that clean air void of particulate enters the carburetion system. In typical art, such canister/filter combinations are annular in plan view, meaning that the canister or container is annular and the filter is annular or in the shape of a ring. However, the present invention may be used with filter arrangements of other forms or shapes without departing from the spirit and scope of the present invention.  
         [0027]     The only requirement of container  104  is that it has enough internal space and height for facilitating rotation of valve  103  from vertical to a rotated position for blocking intake port  103  of carburetor  101 . In this logical view, container  104  is positioned and mounted over port  102  of carburetor  101 . An air filter  105  is illustrated as included within container  104 . In this case, the entire housing of container  104  may be detached from base  106 . In other embodiments, the housing includes the base and the container has a detachable lid. There are many known configurations. In this case, container  104  has a protruding outward dome  308  formed therein for facilitating rotational movement of valve  103  in operation in this example. Many known filter containers though, have enough space and height within the container to facilitate valve  103  without modification such as doming the top to enable more internal room. Filter  105  is a standard cartridge type filter element as is known in the art.  
         [0028]     Container  104  is partially cut away in this example to illustrate valve  103  installed and in section view similar to the view AA of  FIG. 1B . Axis  306  is substantially vertical or perpendicular indicating that valve  103  is actively communicating air into intake port  102  of carburetor  101 , presumable while carburetor  101  is actively performing carburetion. Therefore, in this case valve  103  is seated over port  102  and against ring seal or gasket  203  whereby the intake is completely open for receiving air through air filtering system  104 .  
         [0029]     Container base  106  has a pair mounting brackets  201  mounted thereto in a strategic spaced-apart manner as to enable mounting of valve  103  in a rotable fashion via shaft extensions  303  described further above. Brackets  201  each have receiving openings provided thereto and adapted to receive valve  103  via the shaft extensions ( 303 ) on the valve. In this example, the rear bracket  201  is visible as a hidden boundary. The front bracket  201  is cut away in this view. Seal or gasket  203  may be any pliable, fuel-resistant rubber or other pliable gasket material. In a preferred embodiment, seal  203  is memory resilient such that the bottom portion of valve  103  defined as the minor diameter of opening  302  may form a leak tight seal there against for communicating air into the carburetion system. And, such that when valve  103  is caused to rotate, the spherical surface  301  of valve  103  may form a leak tight seal against seal  203  effectively preventing back streaming of fuel from the carburetor. In this view, valve  103  is vertical and air is passing into carburetor  101  according to the direction of the arrow placed within intake port  102 .  
         [0030]      FIG. 1D  is an elevation view of the system of  FIG. 1C  illustrating anti-back streaming valve  103  rotated to prevent back streaming of fuel according to an embodiment of the present invention. In this view, valve  103  is rotated to approximately 90 degrees off vertical as illustrated by axis  306 . Valve  103  in this position blocks port  102  of carburetor  101 . via surface  301  of valve  103  sealing against seal or gasket  203 . It is noted herein that in a preferred embodiment this state exists whenever an engine system utilizing the carburetor is not running or is powered off. No air may pass from the filtering system into the intake port and no gasoline or vapors from the carburetion system may back stream into the filtering system potentially escaping into the environment. This is illustrated by a curved directional arrow-placed in port  102  showing blockage of the normal back stream of vapors.  
         [0031]     In one embodiment of the present invention, a solenoid system with linkage (not illustrated) is provided and may be mounted to base  106  and may connect to valve  103  at one of shaft extensions  103  where it protrudes through the opening in bracket  201 . Such a system will be described further below. The spherical design-of valve  301  in combination with the resiliency of seal  203  is key to enrabling a repetitive seal in either the vertical or horizontal position of the valve in relation to port  102 . The design and clearances are such that the rotational movement happens about the axis forming the shaft extensions wherein transition from vertical seal to horizontal seal happens with minimal frictional forces against seal  203 . The resiliency of seal  203  functions to take up any slack in tolerance resulting from the “lune” formed in the bottom portion of spherical valve  103  by opening  302 . In one embodiment, brackets  201  have a slot for receiving shaft extension  303  instead of a hole. In this case, the mounting may be a spring mount that urges valve  103  in a downward direction, the range of which may be defined in the slot dimensioning on each bracket  201 . The springs may be housed in the brackets themselves. There are many possibilities.  
         [0032]      FIG. 2  is a perspective view of the system of  FIG. 1D  with the air filter container  104 , filter  105  and valve  103  removed to illustrate mounting brackets  201  and the carburetor inlet  102  for clarity. In this view base  106  on carburetor  101 , with inlet  102  substantially centered, and a pair of mounting brackets  201  attached to the base are shown in perspective. Inlet  102  exhibits circular gasket  203  around the periphery of the inlet opening for sealing to the valve element as described above. Brackets  201  are for rotably mounting valve  103  at openings  202 , to cause the valve element to rotate about an axis through cylindrical openings  202 .  
         [0033]     Carburetor  101  is illustrated as a featureless block in this example for logical representation only. It is clear that carburetor  101  in actual practice may exhibit a variety of features, shapes, and forms none of which would be relevant to the present invention. The only requirement of carburetor  101  is that it has at least one intake port analogous to port  102  that is accessible through the air cleaning canister base. However, accessing carburetor  101  through the base of an air filtration canister should not be construed as a limitation of the invention as it is possible to adapt the valve and mounting apparatus to fit on the carburetor housing itself provided that modifications are made to the base of the canister to accommodate the apparatus and to enable filtered intake into the port. In a preferred embodiment, the apparatus is provided on the base of an air filter canister or container for convenience and practicality. Moreover, the apparatus may be packaged together with the “spec” or stock air cleaner apparatus used for the make of engine and the stock carburetion system of the engine. In this way, much convenience is afforded the user of the system of the invention.  
         [0034]     Base  106  is illustrated with brackets  201  installed. Each bracket  201  has an opening  202  provided therein at strategic location for accepting valve  103  via shaft extensions  303 . Openings  202  may be adapted to contain ring bearings (not illustrated) that may individually and freely rotate within each opening. The shaft extensions then may be adapted to seat into such rings by keyway design such that the shafts them selves cannot rotate within the rings. Using such a common design provides the opportunity to link at least one ring or shaft via linkage to a mechanism such as a solenoid, for example, for causing the desired rotation of valve  103 . Openings  202  may be provided as slots of a specified dimension to allow vertical travel of valve  103  to a range defined by slot dimensioning to further aid in effective and repetitive sealing capability.  
         [0035]      FIG. 3  is a perspective view of the system of  FIG. 1D  with air canister  104  and filter  105  removed illustrating anti-back streaming valve  103  mounted and including components for driving the valve according to an embodiment of the present invention. In this view, carburetor  101  is again illustrated in a logical sense only. Base  106  has brackets  201  installed and valve  103  mounted there between via shaft extensions  303  through openings  202 . The position of valve  103  in this example is horizontal as defined by axis  306  and as was illustrated further above with respect to  FIG. 1D . Spherical surface of valve  301  is effectively blocking intake port  102  of carburetor  101  to prevent back streaming of fuel and fuel vapors. Opening  302  is visible to the right of center indicating a rotation in that particular direction. However, valve  103  may also be caused to rotate in the opposite direction without departing from the spirit and scope of the present invention.  
         [0036]     In one embodiment that has been mentioned repetitively above, a linkage  304  is provided to connect to valve  103  at the shaft extension  303  where it protrudes from opening ( 202 ). Linkage  304  has connection at the opposite end to a horizontally presented, rotable shaft  305  extending from a solenoid-type device further having a vertical driving arm or shaft enclosed in a housing  309 . Linkage  304  may “track” linearly in one direction or the other about the pair of shafts comprising shaft  303  and shaft  305 . The vertical pivot or driver (illustrated as a dotted boundary) within housing  309  may rotate to a specified amount causing linkage  304  to track that amount facilitating controlled rotation such that valve  103  may be held in place or may be rotated to another position. Link  304  may be a rubber belt in one embodiment. In another embodiment, link  304  may be a pair of separate arms. In still another embodiment, link  304  may be metallic chain of sorts engaging teeth provided about the ends of shafts  303 . In this way valve  103  is rotable in a limited sense, the range of rotation governed by the solenoid device.  
         [0037]     In this example, solenoid device  309  has a power wire  310  culminating in a power plug  311  for connecting into the electrical wiring system of a vehicle or system utilizing the carburetion system. In a preferred example, when the system is powered off, the solenoid switches causing rotation of valve  103  to a substantially horizontal position. In one embodiment, the rotation amount is sufficient to cause the intake port to be completely sealed by surface  3012  of valve  103 . That amount may not require a full 90-degree rotation of valve  103 . Therefore, valve  103  may be rotated in some embodiments, less than 90 degrees from vertical without departing from the spirit and scope of the present invention.  
         [0038]     It will be apparent to one with skill in the art that valve  103  including a drive system may be entirely provided within an air filter container and may be adapted to work from within that container provided that the intake or intakes on the carburetion system make entry through the base of the container when the container is installed. In a preferred embodiment, the drive system has connection to the engine hot wire so that when starting the engine, valve  103  rotates to vertical to allow intake of air for normal carburetion. When the engine is shut off, the valve rotates off vertical to seal off the carburetor intake. A safety override measure may be provided in the event of an engine stall in one embodiment whereby if the engine stalls while the vehicle is rolling then the valve would not rotate off of perpendicular so as to enable quick restarting while in motion. A movement sensor may be added to enable this embodiment. Other embodiments are possible without departing from the spirit and scope of the present invention. One alternative embodiment is described below.  
         [0039]      FIG. 4  is an elevation view of a carburetion system  400  enhanced with anti-back streaming valve  103  of  FIG. 1A  and  FIG. 1B  according to another embodiment of the present invention. System  400  includes a carburetor  401 , a remote air-filtering device  403  and a ball valve housing assembly  402 . In this example, carburetor  401  has an air intake port that is connected via an elongated flexible hose  407  to ball valve housing assembly, 402 . Ball valve housing assembly  402  is in turn connected at one ported end via an elongated flexible hose to air filtering device  403 . Air filtering device  403  includes air filter cartridge  404  and is otherwise similar to the air-filtering device described further above with the exception that it is mounted in a remote location from the carburetor.  
         [0040]     The method of the present invention is performed within ball valve assembly housing  402 . Assembly  402  comprises a solid and mountable housing  406  having two lo opposing ports. Housing  406  may be constructed of aluminum, metal, or a durable polymer. Hose  405  in the direction leading to air-filter device  403  connects to one open port of housing  406 . This port remains open and has no valve mechanism associated with it. Hose  407  in the direction leading to carburetor  401  connects to the other port of housing  406 . This port is valve controlled via anti-back streaming valve  103  in a similar fashion as was described previously. Housing  406  includes two brackets  408 , which may be similar to or identical in design as brackets  201  described further above.  
         [0041]     Brackets  408  are strategically spaced apart and provide a mounting location for valve  103  having extensions  303 . In this respect, the mounting features and apparatus may be similar to or identical to that described with reference to base  106  of  FIG. 3 . A drive system including linkage  304  and sister shaft extension  305  as previously described above is also present in this example as are solenoid housing  309  and wiring  310 . The only difference is that the drive system is mounted on the inner side of a back wall of housing  406  in a configuration that presents shaft  305  and linkage  304  in a position to mount with shaft extension  303  of valve  103 .  
         [0042]     Using flexible hose  407  and  405  allows mounting of air filter device  403  and ball valve assembly  402  in virtually any convenient location within an engine compartment. They do not have to be in any symmetrical arrangement with respect to the location of and orientation of carburetor  401  in order to practice the present invention. These features are illustrated in line in this example for clarity only.  
         [0043]     This embodiment function in the same way as the previous embodiment described above. That is to say that valve  103  is caused to pivot to approximately 90 degrees about the axis formed by extension shafts  303 . In this case, a flexible gasket (not illustrated) like gasket  203  described in  FIG. 2  above, might be provided in a recess formed at the opening of the valve-controlled port on housing  402  in the same fashion as was provided in the intake port  102  of carburetor  101  described earlier.  
         [0044]     When valve  103  is positioned so as to be sealed and in communication with the associated port of housing  406 , then air for intake into carburetor  401  travels from air filter device  403 , through hose  405 , through housing  406  and valve  103 , through hose  407  and into the intake at carburetor  401 . When valve  103  is pivoted about the axis formed by shaft extensions  303  to block communication of air into the port, then no intake air passes beyond housing  406  and gasoline vapors or other pollutants are prevented form entering into housing  406  from the carburetor side of system  400 .  
         [0045]     It will be apparent to one with skill in the art of valve ports that the method and apparatus of the present invention may be used in carbureted vehicles such as cars, trucks, farm vehicles, construction vehicles, and the like. The invention may also be applied to other forms of carbureted engines such as those belonging to boats, motorcycles, lawn mowers, chain saws, all terrain vehicles, and so on. The only requirement of the invention is that the application includes a carburetor having at least one port for sealing. The presence of an air filtering canister or container is not specifically required in order to practice the present invention. The presence of an air filter mechanism simply provides one convenient mounting location for the valve assembly and the valve driving system and wiring. For example, in the described embodiment of  FIG. 4 , the valve assembly is entirely remote from any air-filtering device.  
         [0046]     The present invention may be carried out using some of or all of the components illustrated herein without departing from the spirit and scope of the present invention. In light of the embodiments described herein and which are conceivable in application, the present invention should be given the broadest interpretation according to the claims. The present invention shall be limited only by the claims that follow.