Fuel tank vent valve assembly

Abstract

A vent valve assembly is provided including a housing having a float chamber. The vent valve assembly further includes a float assembly having a movable float movable along a longitudinal axis and a plate assembly having a first side facing the float assembly. The float includes float guiding structures operatively engaged with plate guiding structures provided on the plate assembly. The guiding structures constrain the float or guide motion of the float along the longitudinal axis.

Description

FUEL TANK VENT VALVE ASSEMBLYTECHNICAL FIELD

[0001] The present disclosure generally relates to fuel storage systems for vehicles, and more specifically to systems and assemblies that enable safe venting of fuel vapors while preventing unintentional leakage of liquid fuel.BACKGROUND

[0002] Fuel tanks of vehicles require systems and devices that permit safe, consistent operation under a range of conditions. Reliable performance of these safety systems is important in view of the high flammability and high energy density of fuel.

[0003] In particular applications, safety systems are needed to ensure that vapors released by the liquid fuel stored within a fuel tank are safely released, rather than allowed to build up pressure within the fuel tank. By way of example, a rise in ambient temperature and / or solar radiation may raise the temperature of a fuel tank and its contents, thereby increasing the rate of fuel vaporization. In particular applications, fuel tank assemblies require integrated safety features to ensure that a vapor release path does not function as a liquid fuel release path, so as to prevent unintentional leakage.

[0004] As an example, if a tank is over-filled during refueling, liquid fuel level may leak through a passage that is intended for release of fuel vapors, unless the risk is anticipated and mitigated. As a further example, if the fuel vapor release passage is sealed against leakage based on an over-filling event, features are needed to ensure that full functionality of safety systems, such as fuel vapor release, is promptly restored when the fuel level subsequently decreases, and / or when normal operational conditions are restored.SUMMARY OF PARTICULAR EMBODIMENTS

[0005] The present disclosure relates to inventive features that enable and improve performance relating to safe venting of fuel vapors and sealing against leakage of liquid fuel from fuel tanks of vehicles.

[0006] In particular embodiments, a vent valve assembly comprises a housing including a float chamber; a float assembly provided within the float chamber and including a float configured tobe movable along a longitudinal axis of the float assembly, wherein the float includes one or more float guiding structures; and a plate assembly including a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float and guide motion of the float along the longitudinal axis of the float assembly, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with motion of the float, each radial distance taken in a plane perpendicular to the longitudinal axis of the float assembly.

[0007] In particular embodiments, which may combine the features of some or all of the above embodiments, the plate assembly is provided with a first vent orifice aligned with the float chamber. In particular embodiments, which may combine the features of some or all of the above embodiments, an axis passing through at least two of the float guiding structures intersects the longitudinal axis of the float assembly. In particular embodiments, which may combine the features of some or all of the above embodiments, the first radial distance is less than or equal to one -half of the second radial distance.

[0008] In particular embodiments, which may combine the features of some or all of the above embodiments, one or more of the float guiding structures include ribs or rails configured to operatively engage with one or more of the plate guiding structures. In particular embodiments, which may combine the features of some or all of the above embodiments, one or more of the plate guiding structures include ribs or rails configured to operatively engage with one or more of the float guiding structures.

[0009] In particular embodiments, which may combine the features of some or all of the above embodiments, the float assembly includes a platform disposed on an upper surface of the float, the platform angled at a non-parallel angle relative to a plane orthogonal to the longitudinal axis. In particular embodiments, which may combine the features of some or all of the above embodiments, the platform is angled relative to the plane orthogonal to the longitudinal axis at an angle between five degrees and thirty degrees.

[0010] In particular embodiments, which may combine the features of some or all of the above embodiments, \the float assembly includes a membrane elongated along a lengthwise axis and including a first end secured to a first attachment of the float assembly, a second end provided opposite the first end and secured to a second attachment of the float assembly, and a slack portion associated with the second end. In particular embodiments, which may combine the features of some or all of the above embodiments, corresponding to an uppermost position of the float along the longitudinal axis of the float assembly, the membrane is configured to cover and seal the first vent orifice, at least a portion of the membrane being supported by the platform, wherein, based on the float moving away from the uppermost position, the membrane is configured to reopen the vent orifice, the reopening associated with the first end initiating a peeling away of the membrane from the first vent orifice, and wherein at least a part of the slack portion of the membrane includes a curvature about an axis perpendicular to the lengthwise axis of the membrane.

[0011] In particular embodiments, which may combine the features of some or all of the above embodiments, the first vent orifice includes an elongated section aligned with the lengthwise axis of the membrane. In particular embodiments, which may combine the features of some or all of the above embodiments, the slack portion of the membrane facilitates sealing of the first vent orifice by facilitating alignment and constraint of the membrane relative to the vent orifice.

[0012] In particular embodiments, which may combine the features of some or all of the above embodiments, an upper surface of the platform includes a cavity, the cavity including an elongated section aligned with a lengthwise axis of the platform. In particular embodiments, which may combine the features of some or all of the above embodiments, the vent valve assembly further includes a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure.

[0013] In particular embodiments, which may combine the features of some or all of the above embodiments, the second side of the plate assembly includes a plate chamber, wherein the plate assembly includes a second vent orifice separately provided from the first vent orifice and aligned with the head valve assembly.

[0014] In particular embodiments, which may combine the features of some or all of the above embodiments, the head valve assembly is disposed adjacent to the float assembly such that the firstside of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with a vent outlet of the vent valve assembly.

[0015] In particular embodiments, which may combine the features of some or all of the above embodiments, a longitudinal axis of the head valve assembly is laterally offset from the longitudinal axis of the float assembly and oriented parallel to the longitudinal axis of the float assembly.

[0016] In particular embodiments, which may combine the features of some or all of the above embodiments, the float includes a cross-sectional shape including a cutout configured to accommodate at least a portion of the head valve assembly.

[0017] In particular embodiments, which may combine the features of some or all of the above embodiments, a fuel tank valve system including: a fuel tank including a vent outlet; a vent valve assembly operatively coupled with the fuel a housing, the vent valve assembly including: a float chamber; a float assembly provided within the float chamber and including a float configured to be movable along a longitudinal axis of the float assembly, wherein the float includes one or more float guiding structures; a plate assembly including a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float and guide motion of the float along the longitudinal axis; and a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with the motion of the float, each radial distance taken in a plane passing through the float and perpendicular to the longitudinal axis of the float assembly, wherein the head valve assembly is disposed adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with the vent outlet.

[0018] In particular embodiments, which may combine the features of some or all of the above embodiments, a method of assembling a vent valve assembly, including: providing a floatassembly within a housing of the vent valve assembly such that a float of the float assembly is movable along a longitudinal axis of the float assembly, a first side of a plate assembly further provided to face the float assembly; operatively engaging one or more guiding structures of the float assembly respectively with one or more guiding structures of the plate assembly to constrain and guide motion of the float along the longitudinal axis; providing a head valve assembly adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly; and providing the plate assembly with a first vent orifice aligned with the float assembly and a second vent orifice aligned with the head valve assembly, wherein a first radial distance between the longitudinal axis and each of the guiding structures of the float assembly is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with the motion of the float, each radial distance taken in a plane passing through the float and perpendicular to the longitudinal axis of the float assembly.

[0019] In particular embodiments, a vent valve assembly is disclosed including a float provided within a float chamber, the float chamber comprising a sealable outlet orifice, the vent valve assembly provided with a head valve to release fuel vapors.

[0020] In particular embodiments, which may combine the features of some or all above embodiments, the vent valve assembly includes a top plate, a mid plate, and a bottom plate.

[0021] In particular embodiments, which may combine the features of some or all above embodiments, a flexible ribbon is provided for sealing the float chamber outlet orifice against liquid fuel leakage, along with an inclined lower surface of the float chamber outlet orifice, and a corresponding inclined ramp on a float.

[0022] In particular embodiments, which may combine the features of some or all above embodiments, the two ends of the flexible ribbon are coupled to the float upper surface at respective ribbon attachments.

[0023] In particular embodiments, which may combine the features of some or all above embodiments, the upper end of the ribbon is coupled to an upper ribbon attachment on the float, and lower end of the ribbon is coupled to a lower ribbon attachment on the float.

[0024] In particular embodiments, which may combine the features of some or all above embodiments, the lower end of the ribbon incorporates a ribbon slack.

[0025] In particular embodiments, which may combine the features of some or all above embodiments, the ribbon slack comprises a loop.

[0026] In particular embodiments, which may combine the features of some or all above embodiments, the loop of the ribbon loops downward from the remaining ribbon.

[0027] In particular embodiments, which may combine the features of some or all above embodiments, the surface of the float chamber outlet orifice that engages with the ribbon is oval, elliptical, racetrack or slit shaped.

[0028] In particular embodiments, which may combine the features of some or all above embodiments, the ribbon interface of the inclined ramp of the float comprises a cavity.

[0029] In particular embodiments, which may combine the features of some or all above embodiments, the cavity of the ribbon interface corresponds to the shape of the float chamber outlet orifice surface that engages with the ribbon.

[0030] In particular embodiments, which may combine the features of some or all above embodiments, the ribbon interface on the inclined ramp of the float comprises one or more ridges.

[0031] In particular embodiments, which may combine the features of some or all above embodiments, the ribbon interface on the inclined ramp of the float comprises one or more cutouts.

[0032] In particular embodiments, which may combine the features of some or all above embodiments, the ribbon is made of a fluoroelastomer.

[0033] In particular embodiments, which may combine the features of some or all above embodiments, the fluoroelastomer material of the ribbon is further reinforced with a polymer.

[0034] In particular embodiments, which may combine the features of some or all above embodiments, the float includes guide features provide proximate to a longitudinal axis containing a center of buoyance of the float, or a centroid of the float cross-section.

[0035] In particular embodiments, which may combine the features of some or all above embodiments, the mid plate includes float guide ribs configured to interface with and support the guide features provided on the float.

[0036] In particular embodiments, which may combine the features of some or all above embodiments, the float has a moon-shaped cross-section.

[0037] In particular embodiments, which may combine the features of some or all above embodiments, the float has a cross-sectional shape comprising a partial circular shape.

[0038] In particular embodiments, which may combine the features of some or all above embodiments, a mid plate chamber provided between the top plate and the mid plate comprises one or more features to guide or restrict flow.

[0039] In particular embodiments, which may combine the features of some or all above embodiments, an upper surface of a head valve comprises a conical structure to reduce flow losses when the head valve is open.

[0040] In particular embodiments, which may combine the features of some or all above embodiments, a head valve assembly comprises a head valve spring, and the head valve is provided with a head valve skirt for stabilizing the head valve spring.BRIEF DESCRIPTION OF THE DRAWINGS

[0041] To assist in understanding the present disclosure, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0042] FIG. 1A illustrates a schematic front view of a vent valve assembly, according to particular embodiments.

[0043] FIG. IB illustrates a schematic back view of a vent valve assembly, according to particular embodiments.

[0044] FIG. 1C illustrates a schematic side view of a vent valve assembly, according to particular embodiments.

[0045] FIG. ID illustrates a schematic top view of a vent valve assembly, according to particular embodiments.

[0046] FIG. IE illustrates a schematic bottom view of a vent valve assembly, according to particular embodiments.

[0047] FIG. 2A illustrates a schematic top perspective view of a vent valve assembly, according to particular embodiments.

[0048] FIG. 2B illustrates a schematic top perspective view of a vent valve assembly, according to particular embodiments.

[0049] FIG. 2C illustrates a schematic bottom perspective view of a vent valve assembly, according to particular embodiments.

[0050] FIG. 3A illustrates a schematic top perspective cross-sectional view of a vent valve assembly, according to particular embodiments.

[0051] FIG. 3B illustrates a schematic top cross-sectional view of a vent valve assembly, according to particular embodiments.

[0052] FIG. 3C illustrates a schematic side cross-sectional view of a vent valve assembly, according to particular embodiments.

[0053] FIG. 3D illustrates a partially exploded schematic side cross-sectional view of a vent valve assembly, according to particular embodiments.

[0054] FIG. 4A illustrates a schematic top perspective view of a float assembly, according to particular embodiments.

[0055] FIG. 4B illustrates a schematic top view of a float, according to particular embodiments.

[0056] FIG. 4C illustrates a schematic top perspective view of a float, according to particular embodiments.

[0057] FIG. 4D illustrates a schematic partial cross-sectional side view depicting exemplary attachment clips installed in a float, according to particular embodiments.

[0058] FIGs. 4E and 4F illustrate schematic perspective views of an exemplary attachment clip, according to particular embodiments.

[0059] FIG. 5A illustrates a schematic top perspective view of a mid plate, according to particular embodiments.

[0060] FIG. 5B illustrates a schematic bottom perspective view of a mid plate, according to particular embodiments, with an enlarged inset illustrating an inclined orifice.

[0061] FIG. 6A illustrates a schematic side view of a head valve, according to particular embodiments.

[0062] FIG. 6B illustrates a schematic top perspective view of a head valve, according to particular embodiments.DESCRIPTION OF EXAMPLE EMBODIMENTS

[0063] To facilitate a better understanding of the present disclosure, the following examples of certain embodiments are given. The following examples are not to be read to limit or define the scope of the disclosure.

[0064] In accordance with various embodiments of the present disclosure, various mechanisms, assemblies, arrangements, and methods of assembly, manufacture, and / or operation of vent valves for fuel tank systems are disclosed herein.

[0065] With reference to the figures, FIGs. 1A-1E and FIGs. 2A-2C illustrate various schematic views of a vent valve assembly, according to particular embodiments. In particular embodiments, a Grade Vent Valve (GW) assembly may be provided as an exemplary vent valve assembly disclosed herein. By way of example and not limitation, the figures provided may depict a Grade Vent Valve (GW) assembly. By way of example and not limitation, the term “vent valve assembly” may be used in instances in this disclosure to refer to a Grade Vent Valve (GW) assembly.

[0066] In particular embodiments, as illustrated in the figures by way of non-limiting example, a vent valve assembly 105 may comprise a top plate 110, a bottom plate 130, and / or a mid plate 150. In particular embodiments, a housing of vent valve assembly 105 may be formed by one or more of a top plate, a bottom plate, and / or a mid plate. In particular embodiments, mid plate 150 may be referred to as a plate assembly. In particular embodiments, vent valve assembly 105 may comprise one or more attachment features configured for securing vent valve assembly 105 to a fuel tank. By way of example and not limitation, vent valve assembly 105 may comprise attachment portion 120 comprising one or more features for coupling to the inside or outside of a tank (e.g., a fuel tank), such as by welding (e.g., ultrasonic welding), adhesion, and / or other suitable coupling process. In particular embodiments, such as depicted in FIGs. ID and 3A by way of non-limiting example, attachment portion may be provided on and / or associated with a plate or surface of vent valve assembly 105, such as top plate 110. In particular embodiments, attachment portion 120 may comprise one or more protrusions configured to attach with a suitable surface of a tank, such as a fuel tank. In particular embodiments, vent valve assembly 105 may comprise an outlet port 140 provided at a suitable portion, such as the bottom plate by way of non-limiting example, as an outlet conduit for venting fuel vapors released by the fuel tank. In particular embodiments, a combination of a top plate, mid plate, and / or bottom plate may be assembled to form an enclosure for the vent valve assembly 105. In particular embodiments, vent valve assembly 105 may have a circular cross-sectional shape. In particular embodiments, vent valve assembly 105 may have a rectangular cross-sectional shape, or any other suitable shape.

[0067] FIGs. 3A-3D illustrate various schematic cross-sectional views of a vent valve assembly, according to particular embodiments, with FIG. 3D depicting a partially exploded view. With reference to FIGs. 3 A-3D, in particular embodiments, vent valve assembly 105 may comprise a float assembly 200 including a float 210. In particular embodiments, the float may be located within a float chamber 220 and / or housing of vent valve assembly 105. In particular embodiments, float chamber 220 may be provided in or within the bottom plate 130. In particular embodiments, interior parts of a top plate, mid plate, and / or bottom plate may cooperate to form a float chamber 220.

[0068] In particular embodiments, the float may translate along a longitudinal axis (e.g., L-L depicted in FIGs. 3C-3D) of the float chamber 220 and / or float assembly 200 in response to a level of liquid fuel in the fuel tank. In particular embodiments, respective materials of the float 210 and / or the float chamber 220 may be selected so that the interface of the float 210 with the float chamber 220 may comprise desired properties of low friction and / or appropriate clearance under a range of operating conditions.

[0069] In particular embodiments, a longitudinal axis (e.g., L-L) of the float assembly 200 may be substantially vertical for a vehicle located on a horizontal surface. By way of example and not limitation, a vertical longitudinal axis may be parallel, or substantially parallel, to a gravity vector. In particular embodiments, longitudinal axis may not coincide with the vertical direction if the vehicle is located on an inclined and / or other non-horizontal surface. By way of example and not limitation, the longitudinal axis of float traversal may not be aligned with the vertical vector if the vehicle is parked on or traversing a gradient, or if the vehicle has rolled over. By way of example and not limitation, in such situations, the float 210 may remain constrained within the float chamber 220, and / or may be guided or constrained to translate along the longitudinal axis of the float chamber 220 and / or float assembly 200.

[0070] In particular embodiments, float 210 may translate, traverse, and / or otherwise experience motion based on buoyant forces acting on the float 210, such as based on displacement of liquid fuel by the float 210. In particular embodiments, separately or additionally, the float 210 may experience a spring force, such as due to a float spring 230. In particular embodiments, the float 210 may be guided and / or constrained in its motion by guiding features, such as float guides 240. In particular embodiments, such as depicted in FIGs. 3B and / or 4A-4C by way of non-limitingexample, guiding features such as float guides 240 may be located on the float 210 at or proximate to a center of float or center of buoyancy of the float, or to a longitudinal axis thereof. By way of example and not limitation, locating guiding features proximate to a center of buoyance (or an axis thereof) can reduce or eliminate float binding based on moments or torques generated by buoyant forces. In particular embodiments, one or more guiding features located on the float 210 may suitably interface with corresponding features provided external to the float 210. By way of example and not limitation, float guides 240 (comprising, for e.g., slots, rails, and / or other suitable features) may interface with features such as guide ribs 250 disposed on the mid-plate and / or in the float chamber 220 (e.g., FIGs. 3A-3B) to engage, facilitate, and / or selectively constraining the float’s motion.

[0071] By way of example and not limitation, FIG. 3C illustrates an exemplary approximate path 260 for release of fuel vapors from the tank through the assembly. In particular embodiments, while a position of the float along a longitudinal axis of float motion (e.g., L-L) may be determined by the liquid fuel level in the tank, as previously discussed, a small clearance may be provided between the float 210 and the float chamber 220 at their interface. By way of example and not limitation, fuel vapors from the tank may flow past the float through this small clearance, and may occupy the volume above the float within the float chamber 220. In particular embodiments, the float may rise or otherwise move to seal an outlet or orifice located at the top of the float chamber 220 at sufficiently high liquid fuel levels.

[0072] In particular embodiments, a valve may be associated with the outlet orifice of float chamber 220. In particular embodiments, such a valve may be designed and / or calibrated to open at a predetermined pressure level and release the fuel vapor buildup through outlet port 140. By way of example and not limitation, a disk valve or a ball valve may be designed to open at particular threshold vapor pressures, such as pressures exceeding 5 kPa, and / or prevent pressure buildup beyond the designed opening pressure. In particular embodiments (not shown), such a valve may be provided on top of float chamber 220. In particular embodiments, a valve may be provided adjacent to float chamber 220.

[0073] In particular embodiments, a sealable float chamber outlet orifice (e.g., float chamber outlet orifice 270 located at the top of the float chamber 220) may connect to another chamber provided above the float chamber 220 in the vent valve assembly. By way of example and notlimitation, such as depicted in FIG. 3C and / or FIGs. 5A-5B, mid plate inlet 310 may, when open, convey fuel vapors through a mid plate chamber 320 and out of a mid plate outlet 330. In particular embodiments, such a routing of fluid path may enable and / or permit a longitudinally shorter overall dimension for the vent valve assembly. By way of example and not limitation, providing a suitable valve directly above the sealable float chamber 220 may require or occupy substantially larger longitudinal height for the vent valve assembly. In particular embodiments, a shorter overall height (i.e., lower longitudinal height) of the vent valve assembly may be desirable for packaging and other performance within a fuel tank. By way of example and not limitation, such as for a given and / or characteristic float volume, a shorter (in the longitudinal dimension) float having a wider or larger cross-sectional area may permit or enable relatively smaller longitudinal float motion for a given change in liquid fuel level, thereby facilitating a high shut off height for the float assembly 200, and / or an overall reduced height for the vent valve assembly. By way of example and not limitation, a shut off height for the float 210 of the float assembly 200 may correspond to a maximum fuel level, i.e., a maximum permissible height of fuel level, in the fuel tank, thereby corresponding to the fuel capacity of the tank.

[0074] FIGs. 4A-4C illustrate schematic views of a float 210 and / or float assembly 200, according to particular embodiments. In particular embodiments, a cross-sectional shape of a float 210 may be configured to enable efficiently packaging a proximate head valve path and head valve components within vent valve assembly 105. In particular embodiments, a head valve may be referred to as an exit valve and / or an anti-trickle valve. In particular embodiments, a cross-sectional shape of a float 210 may be configured to provide a form factor comprising, such as for a given float volume, a combination of a relatively large cross-sectional area and a relatively small float height (e.g., along a longitudinal axis). By way of example and not limitation, such a form factor may facilitate a shorter overall vent valve assembly height (e.g., along a longitudinal axis), and / or a high shut off height for the vent valve assembly. By way of example and not limitation, a shorter vent valve assembly height and / or high shut off height may enable more efficient packaging of a corresponding vent valve assembly within a fuel tank based on packaging constraints, in turn permitting a larger fuel tank capacity and / or larger vehicle operating range. By way of example and not limitation, a float 210 may comprise a moon-shaped cross-section, such as depicted in FIG. 4B.

[0075] By way of example and not limitation, a float 210 may comprise a cross-sectional shape comprising a circular portion, a partially circular shape, and / or a concavity, cutout, and / or other subtractive aspect, for e.g., relative to the circular portion or partially circular portion. In particular embodiments, providing a head valve 410 alongside the float 210, and / or not above the float 210, may permit the vent valve assembly to be configured for a higher shut off height than would be otherwise possible. In particular embodiments, a low side-wall surface area of float 210, such as by configuring the float 210 to be relatively short (along the longitudinal axis) and relatively large in cross-section, such as for a given volume, can reduce skin friction and / or other drag losses, and facilitate higher vapor flow rate capabilities of the vent valve assembly. By way of example and not limitation, a vent valve assembly may be rated for a fuel vapor flow rate exceeding 40 liters per minute (LPM).

[0076] In particular embodiments, it may be desirable to obtain a high shut-off height for the vent valve assembly. In particular embodiments, a head valve assembly may be provided adjacent to, parallel to, and / or alongside a float assembly, rather than, for example, on top of the float assembly. In particular embodiments, float 210 may comprise a cross-section configured so that a longitudinal axis of the float 210 may intersect with an axis joining guiding structures of the float (e.g., G-G), wherein the longitudinal axis may coincide with and / or be collinear with one or more of the lines of action of a float weight, a float buoyancy force, and / or a float spring force.

[0077] As described herein, it may be desirable in particular embodiments to close and seal a float chamber outlet orifice 270 to prevent outflow and / or leakage of liquid fuel. By way of example and not limitation, over-filling of liquid fuel, tilting of the fuel tank at a gradient, and / or a vehicle roll-over event may require the sealable float chamber outlet orifice 270 to be sealed against liquid fuel leakage. Separately or additionally, in particular embodiments, following a sealing event of the float chamber outlet orifice 270, it may be desirable to promptly restore the functionality of the vapor release passage through the float chamber outlet orifice 270 by reopening the float chamber outlet orifice 270 when the risk of liquid fuel leakage has abated. By way of example and not limitation, following a reduction in the liquid fuel level back to a safe or otherwise acceptable lower level, the float chamber outlet orifice 270 should be open and / or available to release fuel vapors again.

[0078] In particular embodiments, a ribbon-like feature may be provided for selectively sealing the float chamber outlet orifice 270. By way of example and not limitation, the ribbon-like feature may be referred to as a ribbon 420 herein. It will be appreciated that the descriptions herein are non-limiting and intended to provide an understanding only; any suitable structure(s) and / or combinations thereof may be used, and are fully contemplated in this disclosure, to provide these features and aspects.

[0079] In particular embodiments, a ribbon 420 may operate to selectively seal the float chamber outlet orifice 270 based on the float 210 rising based on liquid fuel levels. By way of example and not limitation, the ribbon 420 may abut and / or otherwise close the float chamber outlet orifice 270 in the float chamber 220 based on the float 210 rising to an uppermost extent of longitudinal travel. In particular embodiments, a ribbon 420 configured and provided to seal the float chamber outlet orifice 270 may also be designed to promptly open (for e.g., unseal) and / or restore the float chamber outlet orifice 270 opening and normal fuel vapor venting function. By way of example and not limitation, in particular embodiments, effective unsealing and / or reopening of the ribbon 420 may rely upon equalizing fluid pressure differentials that may exist and hinder reopening. Therefore, in particular embodiments, the interaction between the design and features of ribbon 420, float 210, and float chamber outlet orifice 270 may influence and / or control the efficacy and performance of sealing and reopening performance of the assembly. Some of these aspects are further discussed below.

[0080] According to particular embodiments, the ribbon 420 may comprise a relatively flexible and durable member, membrane, sheet, and / or a combination thereof, such that it can reliably perform the described functions of effective sealing and prompt reopening of the float chamber outlet orifice 270. In particular embodiments, the ribbon 420 may be relatively thin, deformable, and / or flexible. By way of example and not limitation, the material comprising the ribbon 420 may include synthetic rubber, fluoropolymers, fluorosilicone, and / or silicone rubber, in particular embodiments. In particular embodiments, a base ribbon material may optionally be further reinforced by additional materials such as polyester or other polymers.

[0081] In particular embodiments, such as depicted in FIGs. 3D and 4A, an inclined ramp 430 may be provided on float 210 to support the ribbon 420 in the seated sealing position of the ribbon 420. In particular embodiments, such as depicted in FIGs. 3C and 4B, in particular embodiments,the ribbon 420 may be coupled to the float 210 at the ends of the ribbon 420 by means of one or more respective ribbon attachments 440, which may be located on the float 210. According to specific embodiments (not shown), one or more of the ribbon attachment locations may be provided in or on the float chamber 220 instead of the float 210.

[0082] In particular embodiments, such as depicted in FIGs. 3C-3D and 5B, the lower or interfacing surface of the float chamber outlet orifice 270 located on the float chamber 220 that interfaces and engages with the ribbon 420 when sealed may also be inclined or sloped, such that in a sealed configuration, the ribbon 420 may be closely engaged, compressed, constrained, and / or otherwise held in an inclined or sloped orientation, such as between the inclined surface of the float chamber outlet orifice 270 and the inclined ramp 430 on the float 210.

[0083] In particular embodiments, such as depicted in FIG. 4A, the ribbon 420 may be coupled to an upper ribbon attachment 440-1 so as to be held taut at that location. Alternatively or additionally, in particular embodiments, the ribbon 420 may be coupled to a lower ribbon attachment 440-2. In particular embodiments, the ribbon 420 may comprise a ribbon slack 460 provided at least at one of the upper or lower attachments (for e.g., when the ribbon 420 is positioned flat against the inclined ramp 430, and / or away from the float chamber outlet orifice 270). By way of example and not limitation, such as depicted in FIG. 4A, ribbon slack 460 may be provided at the lower ribbon attachment 440-2 as a loop of available ribbon length. By way of example and not limitation, in particular embodiments, the loop of ribbon slack 460 may curl downward from the primary extent of the ribbon 420 prior to and / or proximate to coupling to a lower ribbon attachment 440-2, such as illustrated in at FIG. 3C. In particular embodiments, the loop may curl upward from the primary extent of the ribbon (not shown) prior to coupling to a lower ribbon attachment 440-2.

[0084] It will be appreciated that ribbon attachments 440 may comprise one, two, or more attachments points. While this disclosure illustrates and / or describes particular numbers and / or forms of ribbon attachments 440 to provide an understanding, such description is non-limiting; this disclosure fully contemplates other suitable possibilities in all possible combinations.

[0085] In particular embodiments, such as depicted in FIG. 4A by way of example and not limitation, it may be desirable to locate one or more guiding structures of float assembly 200, such as float guides 240, proximal to the longitudinal axis of the float assembly 200. By way of exampleand not limitation, reducing a radial distance between the longitudinal axis L-L and each of one or more guiding structures of float assembly 200 may reduce a moment or torque acting on float 210 due to forces at the guiding structures. In particular embodiments, such moments or torques can cause binding or sticking, thereby impeding smooth, predictable, and / or reliable motion of float 210 along the longitudinal axis. Accordingly, in particular embodiments, a radial distance between one or more of the guiding structures (e.g., float guides 240), such as R1 depicted by way of nonlimiting example in FIG. 4A and the longitudinal axis of float assembly 200 may be minimized. In particular embodiments, a radial distance R1 between a guiding structure, e.g., float guides 240, and a longitudinal axis of float assembly 200 may be configured to be less than a second radial distance (e.g., R2) between the longitudinal axis and an outer perimeter. In particular embodiments, R1 may be less than or equal to three-quarters of R2. In particular embodiments, R1 may be less than or equal to two-thirds of R2. In particular embodiments, R1 may be less than or equal to one-half of R2. In particular embodiments, R1 may be less than or equal to one-third of R2. In particular embodiments, R1 may be less than or equal to a quarter of R2. In particular embodiments, each radial distance R1 (between a longitudinal axis of float assembly 200 and each guiding structure of float assembly 200) and R2 (between a longitudinal axis of float assembly 200 and an outer perimeter of float 210) may be taken in a plane perpendicular to the longitudinal axis of float 210. In particular embodiments, the plane may be taken to pass through float 210.

[0086] In particular embodiments, an axis passing through at least two of the guiding structures of float assembly 200, for e.g., axis G-G passing through float guides 240 depicted in FIGs. 3B and 4A by way of example and not limitation, may be configured to intersect the longitudinal axis of the float assembly 200, e.g., L-L in FIGs. 3B and 4A. In particular embodiments, a line of action of one or more forces acting on float 210 may be collinear with the longitudinal axis of float assembly 200, wherein the one or more forces acting on float 210 may comprise one or more of a buoyant force acting on float 210, a weight of float 210, and / or a spring force due to float spring 230.

[0087] FIGs. 5A-5B illustrate schematic perspective views of a mid plate, according to particular embodiments. In particular embodiments, FIG. 5B may depict a first side of mid plate 150, wherein the first side is configured to face float assembly 200 when the vent valve assembly 105 is assembled. In particular embodiments, FIG. 5A may depict a second side of mid plate 150opposite the first side. In particular embodiments, respective shapes of the upper and lower openings of the float chamber outlet orifice 270 may be designed to facilitate effective coupling and interoperation with the valve and the ribbon, respectively. In particular embodiments, a cross- sectional shape of the float chamber outlet orifice 270 of the float chamber 220 may transition along the longitudinal axis of the float chamber 220. By way of example and not limitation, such as depicted in FIGs. 5A-5B, a float chamber outlet orifice 270 may transition from a ribbon-facing opening on the that may comprise a substantially elliptical, oval, racetrack, or slit shaped, or other suitable shape (e.g., FIGs. 3D, 5B and inset), to a mid plate inlet that may comprise a substantially circular or other suitable shape (e.g., FIG. 5A).

[0088] In particular embodiments, such as depicted in FIGs. 4B-4C by way of non-limiting example, a ramp (e.g., inclined ramp 430) on the float 210 may be provided with a ribbon interface 470 for supporting the ribbon 420 in the seated and / or sealed position of the ribbon 420. By way of example and not limitation, a ribbon interface 470 may comprise a shape corresponding to a ribbon-facing opening shape of the float chamber outlet orifice 270. In particular embodiments, separately or additionally, the ribbon interface 470 on the float 210 may comprise one or more pockets or cavities, such as pocket 480. In particular embodiments, one or more cavities may function as gas relief pockets under operating conditions. In particular embodiments, one or more other features, such as one or more ridges, may be provided within and / or proximate to the ribbon interface 470. In particular embodiments, one or more ridges, such as ridge 490, and / or other suitable structures may be configured to provide rigidity to the ribbon 420 during a sealing event, thereby preventing wrinkling, flopping, folding, and / or misalignment of the ribbon 420 relative to the desired sealing configuration of the ribbon 420 (e.g., ribbon 420 correctly held between the float chamber outlet orifice 270 and the ribbon interface 470). By way of example and not limitation, such as depicted in FIGs. 4B-4C, a ridge may be centrally and / or longitudinally oriented, and / or may be provided on the ramp and / or float top surface for these and / or other purposes.

[0089] As discussed herein, the ribbon 420 in particular embodiments may be used to selectively seal the vapor release passage through the float chamber outlet orifice 270 when the liquid fuel level has raised the float 210 to an uppermost extent and / or limit, for e.g., to prevent unintended leakage of liquid fuel through the orifice. In operation, in particular embodiments, thefloat 210 may rise based on a rising level of liquid fuel such that the upper surface of the ribbon 420 may engage with the lower surface of the float chamber outlet orifice 270. In particular embodiments, relative to less pliable materials, the relatively flexible and / or deformable structural and / or material characteristics of the ribbon 420 may further compress and thereby provide improved sealing around the float chamber orifice entrance as the float 210 rises to its uppermost extent.

[0090] As discussed herein, in particular embodiments, the ribbon 420 may be designed to promptly restore the functionality of the float chamber outlet orifice 270 to permit fuel vapor release based on cessation of a sealing condition, such as when the liquid fuel level has decreased below its former upper extent or limit. By way of example and not limitation, in such scenarios, it may be desired for the longitudinal float motion (e.g., translation) to closely follow or track the now-decreasing level of liquid fuel, thereby uncovering the vapor release valve passage and / or timely restoring the ability to release unwanted fuel vapors from the fuel tank. However, in particular embodiments in the absence of specific associated design, the float 210 may not readily and / or promptly withdraw downward based on a decrease in liquid fuel level. By way of example and not limitation, a potential difficulty in the desirable prompt downward motion of a float 210 may occur because the instantaneous fluid pressure in the chamber located above the float 210 can tend to decrease based on incipient volume enlargement of the chamber; the corresponding reduction in pressure above the float 210 may accordingly prevent the float 210 from moving down based on the relative pressure differential formed across (above and below) the float’s upper surface. In particular embodiments, separately or additionally, relative pressure conditions, such as existing local pressure conditions, in the mid plate chamber 320 and / or the fuel vapor release passage exiting the float chamber outlet orifice 270 may tend to hold the ribbon 420 closed following an initial ribbon sealing event. By way of example and not limitation, in such situations, it may be desirable to specifically design the ribbon 420 to intentionally and promptly reopen to equalize the pressure above and below the ribbon 420, and / or across the float 210, thereby permitting the float 210 to translate down in tandem with the liquid fuel level decrease, and thereby uncovering the float chamber outlet orifice 270 and / or vapor release passage.

[0091] In particular embodiments, in a seated or sealed position of the ribbon 420, the lower surface of the ribbon 420 (i.e., on a float facing side of the ribbon 420) may fully rest on theinclined ramp 430 of the float 210; the ribbon 420 may accordingly be held sealed against a correspondingly inclined lower opening of the float chamber outlet orifice 270. In particular embodiments, a gas relief pocket or cavity (e.g., pocket 480) may be provided in the ribbon interface 470 of the inclined ramp 430 of the float 210, such as depicted in FIGs. 4B-4C by way of non-limiting example. In particular embodiments, a gas relief pocket may permit the ribbon 420 to better conform for tighter sealing against the float chamber outlet orifice 270. In particular embodiments, one or more ridges may support the ribbon 420 from collapsing, such as into a cavity of the ribbon interface 470.

[0092] In particular embodiments, when the liquid fuel level first decreases from a maximum level corresponding to an uppermost extent or travel of the float 210, a ribbon 420 may be configured so that a resultant downward force of the float 210 may act, by intentional design, on the ribbon 420 first at a taut (i.e., lacking slack) ribbon attachment location. By way of example and not limitation, such as depicted in FIG. 3D, an upper ribbon attachment 440-1 may be configured to be taut, i.e., lack ribbon slack, under these conditions. In particular embodiments, a ribbon slack 460 provided at another end (e.g., the lower ribbon attachment 440-2 of FIG. 3D) may prevent this force from being initially experienced by the ribbon 420 at that other end (e.g., the lower ribbon attachment location). In particular embodiments, such a taut / slack ribbon configuration can provide a peel-away effect to facilitate prompt re-opening of the float chamber outlet orifice 270 based on need (e.g., based on decreasing liquid fuel level conditions).

[0093] By way of example and not limitation, in particular embodiments, when the float 210 experiences a net downward force (e.g., by decreasing liquid fuel levels), a stretched or taut upper end of the inclined, seated ribbon 420 may be effectively and promptly withdrawn from the float chamber outlet orifice 270 while the lower slack end may briefly or temporarily flex and / or rise above the inclined ramp 430 of the float 210. By way of example and not limitation, the combination of these aspects can provide a resultant peel-away effect to the ribbon 420, which may comprise initially at least partially opening the float chamber outlet orifice 270 based on the ribbon’s action, thereby rapidly neutralizing any pressure differentials that may have otherwise prevented the effective downward translation of the float 210 along its longitudinal axis of motion, and thereby facilitating a subsequent full and prompt opening of the float chamber outlet orifice 270 to resume vapor flow functionality. In particular embodiments, as discussed, the lower end ofthe ribbon 420 may, by intentional design, briefly or temporarily lose some of its ribbon slack, and / or the ribbon 420 may briefly rise above the inclined ramp 430 of the float 210 during the float’s downward travel.

[0094] In particular embodiments, as discussed herein, the ribbon slack 460 provided at a ribbon end can facilitate prompt and effective reopening of the float chamber outlet orifice 270. In particular embodiments, separately or additionally, features related to the ribbon 420 and / or ribbon slack 460, such as a loop, may facilitate or enable better sealing performance of sealing the float chamber outlet orifice 270. By way of example and not limitation, a loop formed in the ribbon 420 to provide the ribbon slack 460 (e.g., FIG. 3D), individually or in combination with the form and material of the ribbon 420, may facilitate a stiffening of the ribbon 420 against distortion as the ribbon 420 is raised off the inclined ramp 430 of the float 210. By way of example and not limitation, a loop about a transverse or lateral axis of the ribbon 420, such as depicted in FIG. 3D, may provide a stiffening and / or resistance to particular deformations of the ribbon 420. In particular embodiments, the ribbon 420 may act as a spring in tension due to the loop. In particular embodiments, such stiffening of the ribbon 420 may prevent wrinkling, flopping, folding, or other undesired deformation or misalignment of the ribbon 420. As a non-limiting example, high fluid flow rates in the vicinity of the ribbon 420 may produce significant pressures and / or forces based on flow dynamics, which may displace, misalign, and / or otherwise hinder effective location of ribbon 420 relative to the float chamber outlet orifice 270. The abovementioned beneficial aspects of features related to the ribbon 420 and / or ribbon slack 460 may therefore provide rigidity to the ribbon 420, and / or the ability to present the ribbon 420 to the float chamber outlet orifice 270 in a flat and aligned manner, for improved sealing performance. In particular embodiments, a loop may spiral and / or loop downward (such as shown in FIG. 3D by way of non-limiting example), or a loop may spiral and / or loop upward (not shown). In particular embodiments, a loop may be formed in any suitable portion of the ribbon 420.

[0095] In particular embodiments, one or more gas escape passages and / or cutouts may be provided at the ribbon interface. By way of example and not limitation, such as depicted by FIG. 4B, a cutout 495 may be configured and provided to prevent air and / or other gas from being trapped in a cavity or pocket of the ribbon interface. By way of example and not limitation, an absence of a cutout or other suitable corresponding feature may lead to a suction or vacuum forming in aribbon interface cavity under the seated ribbon 420, potentially hindering peeling away of the ribbon 420 when re-opening is desired.

[0096] In particular embodiments, ribbon attachments 440 may have structure and form to at least constrain the ribbon 420 as desired, as described herein, as well as for durability, ease of manufacturing, and / or ease of assembly. In particular embodiments, ribbon attachments 440 may comprise, as non-limiting examples, one or more levers, clips, buttons, posts, split-posts, notches, hinges, and / or snap fits. By way of example and not limitation, FIGs. 3D, 4A-4F illustrate several exemplary ribbon attachments 440 and features. By way of example and not limitation, FIG. 4A illustrates particular embodiments of clip ribbon attachments 440. In particular embodiments, clip attachments may be provided with snap-in clip features for positive and quick assembly. In particular embodiments, a one or more posts, holes, pins, and / or other indexing feature(s), such as post 560, may be provided for aligning and / or constraining the ribbon 420 to the ramp and / or float surface, such as by inserting and engaging with corresponding holes in the ribbon 420. In particular embodiments, clip attachments, such as clip 550 by way of non-limiting example, may include one or more retaining features to connect and / or retain the attachment with ribbon 420 held in place. By way of example and not limitation, FIG. 4D-4F illustrate particular embodiments of clip 550 comprising snap-in hook 570, one or more of which may be provided to facilitate rapid, positive, and / or secure assembly. In particular embodiments, access may be provided for disassembly or removal of attachments and / or clips, such as via one or more cutouts 580 depicted in FIGs. 4D-4F by way of non-limiting example.

[0097] FIGs. 6A-6B illustrate schematic views of a head valve, according to particular embodiments. In particular embodiments, a head valve 410 may be provided in the vent valve assembly. In particular embodiments, a head valve 410 may be provided downstream of a mid plate outlet 330, and may be calibrated (e.g., via a head valve spring or another suitable biasing member) to selectively open based on a minimum opening fluid pressure. By way of example and not limitation, a head valve 410 may be calibrated to open at fluid pressures equaling or exceeding 5 kPa. In particular embodiments, an exemplary head valve 410, such as provided in the configuration depicted in FIGs. 3C and 3D by way of non-limiting example, may be referred to as, may be synonymous with, and / or may function as, an anti-trickle valve. By way of example and not limitation, an anti-trickle valve may be configured to remain closed at low fluid pressures, suchas to prevent fuel over-filling, fuel leakage, and / or fuel trickling, and may open only based on a predetermined and calibrated minimum static pressure acting on the upstream side of the head valve 410. Accordingly, in particular embodiments, a head valve 410 may function as an antitrickle valve. By way of example and not limitation, an anti-trickle valve may prevent fuel overfilling by providing a minimum resisting pressure rather than leaving the passage open. By way of example and not limitation, an anti-trickle valve can help to reduce liquid carry-over losses for the vent valve assembly.

[0098] In particular embodiments, a head valve 410 may be provided with one or more flow improvement features to streamline and / or smoothen a fluid flow past the head valve 410, such as when the valve is open. By way of example and not limitation, such as depicted in FIG. 6A, an upstream or other surface of the head valve 410 that is flow direction facing (e.g., an upper surface of the head valve 410) may comprise a suitable streamlining flow improvement feature, such as protrusion 510. By way of example and not limitation, protrusion 510 may comprise a conical leading surface. By way of example and not limitation, one or more flow facing and / or flow interfacing surfaces of the head valve 410 may preferentially avoid particular cavities, bluff steps or faces, and / or other features that may increase flow losses, and / or destabilize the head valve operation based on flow dynamics. By way of example and not limitation, reducing fluid flow drag losses, such as described herein, can facilitate increasing the vapor flow rate capabilities of the vent valve assembly.

[0099] In particular embodiments, a head valve 410 and / or other suitable features related to a head valve chamber 520 may comprise spring guiding structures and / or features. By way of example and not limitation, such as depicted in FIGs. 3D and 6B, a head valve 410 may be provided with a head valve skirt 530 for stabilizing a head valve spring, such as by reducing or eliminating exit spring buckling during installation and / or operation.

[0100] In particular embodiments, a diameter of a head valve 410 may be determined based on a desired head valve opening characteristic. By way of example and not limitation, for a relatively small diameter head valve compared to a relatively larger diameter head valve, a fraction of exposed flow-facing surface area of the head valve varies differently between the smaller and larger valves as the valve changes between a fully closed, partially open, and fully open state. Accordingly, a larger diameter head valve may provide a more distinct transition or valveswitching (opening and / or closing) characteristic based on local pressure conditions. In particular embodiments, a larger diameter head valve may be preferred for at least the valve switching characteristics, subject to balancing an ability to provide a relatively large float cross-section to provide a sufficiently high shut off height, based on design requirements. Accordingly, particular cross-section shapes of a float 210, such as the moon-shaped form in the non-limiting example illustrated in FIG. 4B, may be preferred in some embodiments.

[0101] In particular embodiments, guiding and / or restricting features may be associated with the top surface of the float chamber 220, mid plate 150, and / or mid plate chamber 320, such as to guide flows (e.g., as-designed fuel vapor flow when float chamber outlet orifice 270 is unsealed), and / or to restrict, retard, separate out, return, and / or reverse the incipient or actual flow of liquid fuel, which may be considered undesirable leakage as an outflow. By way of example and not limitation, as depicted in FIGs. 5A-5B, one or more baffles (e.g., baffles 340), tortuous paths, orifice sizing and shapes, and / or orifice transition features (e.g., orifice transition 345) may be provided to individually and / or cooperatively perform as guiding and / or restricting features. By way of example and not limitation, fuel vapor flows may tend to entrain and / or otherwise carry liquid fuel components with the vapor flow, especially at high vapor flow rates. In particular embodiments, guiding and / or restricting features, such as described herein, can induce liquid-laden vapor flows to release or separate out their liquid components, whereupon the liquid components can drip back based on the flow paths and architecture provided with the features herein (for e.g., relative configuration of baffles and obstructions, and / or downward draft or gradient of upper surfaces and / or orifice transition 345 in FIG. 5A). By way of example and not limitation, guiding and / or restricting features may reduce, separate, and / or return liquid carry over, such as due to vehicle acceleration and / or sloshing, back to fuel tank.

[0102] In particular embodiments, fluid fuel (e.g., fuel vapors) may further continue to flow out of a mid plate outlet 330 to act on a head valve 410. In particular embodiments, a head valve 410 may be disposed in a head valve chamber 520 separate from the float chamber 220. In particular embodiments, the head valve chamber 520 may be provided in or within the bottom plate 130. In particular embodiments, interior parts of a top plate 110, mid plate 150, and / or bottom plate 130 may cooperate to form the head valve chamber 520. In particular embodiments, the head valve chamber 520 may be disposed adjacent to the float chamber 220. By way of example andnot limitation, the head valve chamber 520 may be parallel, or substantially parallel, to the float chamber 220. By way of example and not limitation, a longitudinal axis (e.g., E-E) of the head valve chamber 520 may be parallel, or substantially parallel, to a longitudinal axis (e.g., L-L) of the float chamber 220.

[0103] In particular embodiments, one or more interlocking and / or sealing features may be provided to assemble parts of the vent valve assembly, and / or effectively contain and seal fuel- related fluids within the vent valve assembly. By way of example and not limitation, interlocking tabs may be provided to connect two or more of a bottom plate 130, mid plate 150, and / or top plate 110. By way of example and not limitation, seals such as labyrinth seals (for e.g., seals 350 as depicted in FIG. 5A for top plate 110 and mid plate 150 interfacing; for e.g., as depicted in FIG. 3C and 5B for mid plate 150 and bottom plate 130 interfacing; for e.g., seal 355 provided to seal the head valve chamber 520) may be provided between interfacing surfaces of vent valve assembly components to securely contain any cross-seal fluid communication, leakage, and / or contamination. In particular embodiments, seals such as labyrinth seals may separately or additionally provide press-fit ability for assembly. In particular embodiments, other kinds of seals, such as O-rings, may be separately or additionally used in the vent valve assembly.

[0104] The benefits and advantages of the inventive concepts are now believed to have been amply illustrated in view of the exemplary embodiments disclosed.Clauses

[0105] Clause 1. A vent valve assembly comprising: a housing comprising a float chamber; a float assembly provided within the float chamber and comprising a float configured to be movable along a longitudinal axis of the float assembly, wherein the float comprises one or more float guiding structures; and a plate assembly comprising a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float and guide motion of the float along the longitudinal axis of the float assembly, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outerperimeter of the float to facilitate reduced binding associated with motion of the float, each radial distance taken in a plane perpendicular to the longitudinal axis of the float assembly.

[0106] Clause 2. The vent valve assembly of clause 1 , wherein the plate assembly is provided with a first vent orifice aligned with the float chamber.

[0107] Clause 3. The vent valve assembly of any of clauses 1 or 2, wherein an axis passing through at least two of the float guiding structures intersects the longitudinal axis of the float assembly.

[0108] Clause 4. The vent valve assembly of any of clauses 1 to 3, wherein the first radial distance is less than or equal to one-half of the second radial distance.

[0109] Clause 5. The vent valve assembly of any of clauses 2 to 4, wherein one or more of the float guiding structures comprise ribs or rails configured to operatively engage with one or more of the plate guiding structures.

[0110] Clause 6. The vent valve assembly of any of clauses 2 to 5, wherein one or more of the plate guiding structures comprise ribs or rails configured to operatively engage with one or more of the float guiding structures.

[0111] Clause 7. The vent valve assembly of any of clauses 2 to 6, wherein the float assembly further comprises a platform disposed on an upper surface of the float, the platform angled at a non-parallel angle relative to a plane orthogonal to the longitudinal axis.

[0112] Clause 8. The vent valve assembly of clause 7, wherein the platform is angled relative to the plane orthogonal to the longitudinal axis at an angle between five degrees and thirty degrees.

[0113] Clause 9. The vent valve assembly of clause 7, wherein the float assembly further comprises a membrane elongated along a lengthwise axis and comprising a first end secured to a first attachment of the float assembly, a second end provided opposite the first end and secured to a second attachment of the float assembly, and a slack portion associated with the second end.

[0114] Clause 10. The vent valve assembly of clause 9, wherein, corresponding to an uppermost position of the float along the longitudinal axis of the float assembly, the membrane is configured to cover and seal the first vent orifice, at least a portion of the membrane being supported by the platform, wherein, based on the float moving away from the uppermost position, the membrane is configured to reopen the vent orifice, the reopening associated with the first end initiating a peeling away of the membrane from the first vent orifice, and wherein at least a part ofthe slack portion of the membrane comprises a curvature about an axis perpendicular to the lengthwise axis of the membrane.

[0115] Clause 11. The vent valve assembly of any of clauses 9 or 10, wherein the first vent orifice comprises an elongated section aligned with the lengthwise axis of the membrane.

[0116] Clause 12. The vent valve assembly of any of clauses 9 to 11, wherein the slack portion of the membrane facilitates sealing of the first vent orifice by facilitating alignment and constraint of the membrane relative to the vent orifice.

[0117] Clause 13. The vent valve assembly of any of clauses 7 to 12, wherein an upper surface of the platform comprises a cavity, the cavity comprising an elongated section aligned with a lengthwise axis of the platform.

[0118] Clause 14. The vent valve assembly of any of clauses 2 to 13, further comprising a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure.

[0119] Clause 15. The vent valve assembly of clause 14, wherein the second side of the plate assembly comprises a plate chamber, and wherein the plate assembly comprises a second vent orifice separately provided from the first vent orifice and aligned with the head valve assembly.

[0120] Clause 16. The vent valve assembly of any of clauses 14 or 15, wherein the head valve assembly is disposed adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with a vent outlet of the vent valve assembly.

[0121] Clause 17. The vent valve assembly of clause 16, further comprising a longitudinal axis of the head valve assembly laterally offset from the longitudinal axis of the float assembly and oriented parallel to the longitudinal axis of the float assembly.

[0122] Clause 18. The vent valve assembly of any of clauses 14 to 17, wherein the float comprises a cross-sectional shape including a cutout configured to accommodate at least a portion of the head valve assembly.

[0123] Clause 19. A fuel tank valve system comprising: a fuel tank comprising a vent outlet; a vent valve assembly operatively coupled with the fuel a housing, the vent valve assembly comprising: a float chamber; a float assembly provided within the float chamber and comprising a float configured to be movable along a longitudinal axis of the float assembly, wherein the floatcomprises one or more float guiding structures; a plate assembly comprising a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float and guide motion of the float along the longitudinal axis; and a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with the motion of the float, each radial distance taken in a plane passing through the float and perpendicular to the longitudinal axis of the float assembly, wherein the head valve assembly is disposed adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with the vent outlet.

[0124] Clause 20. A method of assembling a vent valve assembly, comprising: providing a float assembly within a housing of the vent valve assembly such that a float of the float assembly is movable along a longitudinal axis of the float assembly, a first side of a plate assembly further provided to face the float assembly; operatively engaging one or more guiding structures of the float assembly respectively with one or more guiding structures of the plate assembly to constrain and guide motion of the float along the longitudinal axis; providing a head valve assembly adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly; and providing the plate assembly with a first vent orifice aligned with the float assembly and a second vent orifice aligned with the head valve assembly, wherein a first radial distance between the longitudinal axis and each of the guiding structures of the float assembly is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with the motion of the float, each radial distance taken in a plane passing through the float and perpendicular to the longitudinal axis of the float assembly.Miscellaneous

[0125] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. For example, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments that may not be described in words or by reference to the drawings, but which are fully contemplated. It will also be understood that changes and modifications may be made by those of ordinary skill within the scope of the disclosure, illustrations, and / or the following claims. Such variations are fully contemplated herein and not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0126] The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and / or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.

[0127] It should be noted that figures provided herein may be illustrated schematically rather than literally or precisely; components and aspects of the figures may not necessarily be to scale. Moreover, while like reference labels or numerals may designate corresponding parts throughout the different views in many cases, like parts may not always be provided with like reference numerals or labels in each view. Further, like parts may not be labeled in every view or figure.Numerical ranges recited in this application should be construed to be inclusive of the end points of the stated ranges. Particular axes, such as one or more rotational, lateral and / or longitudinal axes, which may be omitted herein in some illustrations, should be construed to exist in every illustration or situation where it is referred to, or to which it reasonably corresponds.

Claims

CLAIMS:

1. A vent valve assembly comprising: a housing comprising a float chamber; a float assembly provided within the float chamber and comprising a float configured to be movable along a longitudinal axis of the float assembly, wherein the float comprises one or more float guiding structures; and a plate assembly comprising a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float or guide motion of the float along the longitudinal axis of the float assembly, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with motion of the float, each radial distance taken in a plane perpendicular to the longitudinal axis of the float assembly.

2. The vent valve assembly of claim 1 , wherein the plate assembly is provided with a first vent orifice aligned with the float chamber.

3. The vent valve assembly of any of claims 1 or 2, wherein an axis passing through at least two of the float guiding structures intersects the longitudinal axis of the float assembly.

4. The vent valve assembly of any of claims 1 to 3, wherein the first radial distance is less than or equal to one-half of the second radial distance.

5. The vent valve assembly of any of claims 2 to 4, wherein one or more of the float guiding structures comprise ribs or rails configured to operatively engage with one or more of the plate guiding structures.

6. The vent valve assembly of any of claims 2 to 5, wherein one or more of the plate guiding structures comprise ribs or rails configured to operatively engage with one or more of the float guiding structures.

7. The vent valve assembly of any of claims 2 to 6, wherein the float assembly further comprises a platform disposed on an upper surface of the float, the platform angled at a nonparallel angle relative to a plane orthogonal to the longitudinal axis.

8. The vent valve assembly of claim 7, wherein the platform is angled relative to the plane orthogonal to the longitudinal axis at an angle between five degrees and thirty degrees.

9. The vent valve assembly of claim 7, wherein the float assembly further comprises a membrane elongated along a lengthwise axis and comprising a first end secured to a first attachment of the float assembly, a second end provided opposite the first end and secured to a second attachment of the float assembly, and a slack portion associated with the second end.

10. The vent valve assembly of claim 9, wherein, corresponding to an uppermost position of the float along the longitudinal axis of the float assembly, the membrane is configured to cover and seal the first vent orifice, at least a portion of the membrane being supported by the platform, wherein, based on the float moving away from the uppermost position, the membrane is configured to reopen the vent orifice, the reopening associated with the first end initiating a peeling away of the membrane from the first vent orifice, and wherein at least a part of the slack portion of the membrane comprises a curvature about an axis perpendicular to the lengthwise axis of the membrane.

11. The vent valve assembly of any of claims 9 or 10, wherein the first vent orifice comprises an elongated section aligned with the lengthwise axis of the membrane.

12. The vent valve assembly of any of claims 9 to 11, wherein the slack portion of the membrane facilitates sealing of the first vent orifice by facilitating alignment and constraint of the membrane relative to the vent orifice.

13. The vent valve assembly of any of claims 7 to 12, wherein an upper surface of the platform comprises a cavity, the cavity comprising an elongated section aligned with a lengthwise axis of the platform.

14. The vent valve assembly of any of claims 2 to 13, further comprising a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure.

15. The vent valve assembly of claim 14, wherein the second side of the plate assembly comprises a plate chamber, and wherein the plate assembly comprises a second vent orifice separately provided from the first vent orifice and aligned with the head valve assembly.

16. The vent valve assembly of any of claims 14 or 15, wherein the head valve assembly is disposed adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with a vent outlet of the vent valve assembly.

17. The vent valve assembly of claim 16, further comprising a longitudinal axis of the head valve assembly laterally offset from the longitudinal axis of the float assembly and oriented parallel to the longitudinal axis of the float assembly.

18. The vent valve assembly of any of claims 14 to 17, wherein the float comprises a cross-sectional shape including a cutout configured to accommodate at least a portion of the head valve assembly.

19. A fuel tank valve system comprising:a fuel tank comprising a vent outlet; a vent valve assembly operatively coupled with the fuel a housing, the vent valve assembly comprising: a float chamber; a float assembly provided within the float chamber and comprising a float configured to be movable along a longitudinal axis of the float assembly, wherein the float comprises one or more float guiding structures; a plate assembly comprising a first side and a second side opposite the first side, the plate assembly disposed with the first side facing the float assembly within the float chamber, wherein the first side of the plate assembly is provided with one or more plate guiding structures configured to respectively operatively engage with the one or more float guiding structures to constrain the float or guide motion of the float along the longitudinal axis; and a head valve assembly configured to selectively open based on a fluid pressure acting on the head valve assembly exceeding a threshold opening pressure, wherein a first radial distance between the longitudinal axis and each of the float guiding structures is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with motion of the float, each radial distance taken in a plane perpendicular to the longitudinal axis of the float assembly, wherein the head valve assembly is disposed adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly, and wherein the head valve assembly is provided in fluid communication with the vent outlet.

20. A method of assembling a vent valve assembly, comprising: providing a float assembly within a housing of the vent valve assembly such that a float of the float assembly is movable along a longitudinal axis of the float assembly, a first side of a plate assembly further provided to face the float assembly; operatively engaging one or more guiding structures of the float assembly respectively with one or more guiding structures of the plate assembly to constrain the float or guide motion of the float along the longitudinal axis;providing a head valve assembly adjacent to the float assembly such that the first side of the plate assembly faces the head valve assembly; and providing the plate assembly with a first vent orifice aligned with the float assembly and a second vent orifice aligned with the head valve assembly, wherein a first radial distance between the longitudinal axis and each of the guiding structures of the float assembly is less than a second radial distance between the longitudinal axis and an outer perimeter of the float to facilitate reduced binding associated with motion of the float, each radial distance taken in a plane perpendicular to the longitudinal axis of the float assembly.

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