Abstract:
A pop up gas cap for a gas tank includes an outer sleeve and a seal cap engaging the sleeve upon actuation of a lid which rotatably brings the seal cap and sleeve in a lock in position. After locking the sleeve and the gas cap, the lid is adapted to move between an outer pop position and an inner flush position thereof, in which the lid is flushed with the gas tank&#39;s outer surface.

Description:
FIELD OF THE INVENTION 
     The invention relates to a removable filler cap assembly for a fuel tank of motor vehicles. Particularly, the invention relates to a pop up gas cap for closing fuel tanks of motorcycles and powerboats. 
     SUMMARY OF THE INVENTION 
     Numerous filler cap assemblies are known in the art. Many of the known gas cap arrangements use gripping handles, as for example, U.S. Pat. No. 2,866,572 (Llewhellin). This patent discloses a flush-fitting filler cap assembly designed for aircraft, comprising a carrier in the form of a shallow hollow cup having an inwardly directed circumferential flange. The carrier presses down on a diaphragm contacting a sealing ring within a sleeve via a bayonet slot connection. The carrier is rotated by a finger bar. A cover plate having a slot to accommodate the finger bar is necessary to provide a flush surface wherein a spring biases the cover plate up against the carrier&#39;s inwardly directed circumferential flange. 
     Still another arrangements utilize keys which are mounted pivotally on top of the gas caps. Thus, for example, U.S. Pat. No. 3,476,285 (De Pew) discloses a filler cap assembly, comprising a closure plate formed with a pivotal key thereon and having alternate sections of greater and lesser diameter. A cup-shaped pressure plate having a shaft, a spring biasing the pressure plate upward, a resilient sealing ring. Upon pivoting the key having a curved cam surface operating against a wear plate, the closure plate is forced against the pressure plate when the key is in a closed position. 
     U.S. Pat. No. 4,189,059 (Shaw) discloses a filler cap assembly comprising a plug member having an O-ring seal, a retaining member, a locking member, a compression spring and an operating shaft. The compression spring biases the locking member away from the plug and retaining members. To lock the plug member in the tank opening, a key is rotated about the axis of the operating shaft, drawing fingers of the locking member upward into engagement with an adapter contacting the retaining member, thereby compressing the O-ring against the plug member. 
     U.S. Pat. No. 4,811,763 (Kupske) discloses an arrangement of a keyless gas cap for filling motorcycle fuel tanks. The gas cap comprises a short pipe piece housed within a cylinder means, and a coil spring. The gas cap is hingedly mounted on the gas tank and protrudes thereabove in a closed position thereof. 
     Many of the above discussed arrangements using a handle means for opening and closing of gas tanks may have unappealing designs of gas filling arrangements, which are likely to be particularly noticeable on motorcycles and powerboats. 
     Further, many of the known gas cap assemblies may likely not have a means adapted to receive an excess of fuel if the gas tank has been overfilled. 
     SUMMARY OF INVENTION 
     The novelty of the present invention is a flush-mount gas cap which is opened by unseating a pop up mechanism which is operatively connected with a lid adapted to be angularly displaced in order to unscrew a seal cap from engagement with a gas tank. 
     The flush-mount gas cap according to the invention includes a seal cap having a recessed interior which receives a spring-loaded shaft. The shaft&#39;s top end is fixed to an underside of the lid, whereas the shaft&#39;s lower end has a pin extending transversely to the shaft. The seal cap&#39;s bottom is formed with a pair of intersecting shallow and deep recesses having different axial cross-sectional depths, so that the pin selectively engages the recesses upon controllably displacing the lid. When the pin is received in the shallow recess, the cap&#39;s lid is in its flush position in which the lid&#39;s top surface is juxtaposed with the seal cap&#39;s upper surface. Alternatively, upon engagement of the pin in the deep recess, the cap is in its pop up position in which the cap&#39;s top surface is spaced from the sleeve&#39;s upper surface. 
     The seal cap includes an overfill compartment which is formed in the seal cap at distance from the bottom thereof and is in flow communication with the gas tank in the pop up position of the cap. This is achieved by having a channel which opens at opposite ends thereof into the overfill compartment and the deep recess respectively. 
     The flush gas cap according to the invention may be easily adapted for use with existing arrangements for filling fuel tanks of motor vehicles. In order to utilize the inventive gas cap with the existing arrangements, it is necessary that the seal cap of the invention be provided with a means for engaging the inner surface of an outer sleeve which has been mounted on a motor vehicle. 
     The invention also contemplates a flush-mount gas cap assembly including an outer sleeve or sleeve formed with an upper mounting flange and having a hollow inner surface which receives a fuel discharge nozzle during a filling operation. After the gas tank is filled with fuel, the seal cap releasably engages an interior of the outer sleeve to advance to a position in which the sleeve&#39;s top upper mounting flange is located either below or substantially flush with the seal cap&#39;s top surface. The spring-loaded seal cap is then displaced inwardly and, upon applying a rotational torque, the pin engages the shallow recess so that the lids &#39;s upper surface is substantially flushed with the seal cap&#39;s top surface and with the gas tank&#39;s surface. 
     It is therefore an object of the invention to provide an improved gas mount assembly overcoming drawbacks of the prior art. 
     Still another object of the present invention is provide a pop up gas mount assembly adapted to have an overfill cap, which is in flow communication with the gas tank. 
     Another object of the present invention is to provide a pop us gas mount assembly that may be easily adapted to be used with existing arrangements for filling tanks of motor vehicles. 
     Yet another object of the invention is to provide a pop up gas assembly which is aesthetically appealing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other object, features and advantages will become more readily apparent from the following description of the invention, references being made to the accompanying drawings, in which: 
     FIG. 1 is a side perspective view of a gas cap according to the invention. 
     FIG. 2 is a cross sectional view of the gas cap of FIG. 1 in its intermediate position taken along axis A—A. 
     FIG. 3 is a cross sectional view of the gas cap of FIG. 1 taken along lines III—-III and illustrating the gas cap in its flush position. 
     FIG. 4 is a cross sectional view of the gas cap of FIG. 1 in its pop up position. 
     FIG. 5 illustrates a prior art gas cap assembly. 
     FIG. 5A is a perspective view of a gas tank with a gas cap assembly of the invention which includes the gas cap shown in FIG.  1 . 
     FIG. 6 is an exploded perspective view of a gas cap assembly according to the invention. 
     FIG. 7 is another exploded view of a gas cap assembly according to the invention. 
     FIG. 8 is an axial cross-sectional view of the assembly of FIG. 5 showing the cap gas of FIG. 1 in a flush position thereof. 
     FIG. 9 is the same view as the one illustrated in FIG. 8 but showing the gas cap of FIG. 1 in an intermediary position. 
     FIG. 10 is the same view as the one of FIG. 8 but showing the gas cap of FIG. 1 in a pop up position. 
     FIG. 11 is a cross-sectional view of a stop according to one of the aspects of the present invention. 
    
    
     Although the following description relates to a gas cap assembly shown in the drawings with its axis in a vertical direction, it will be understood that the assembly according to this invention could be used in any position. Therefore the words “upper” and “lower” have merely been used herein for convenience of description and are intended to cover a gas cap assembly however oriented. 
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates a gas cap  1  including a lid  3  which is formed with an underside  5 . A shaft  9  extending along a shaft axis A-A is mounted rotatably fixed on the underside  5 . A free end of the shaft  9  is provided with a pin  11  extending transversely to the axis A—A and rotationally fixed with the shaft  9 . A seal cap  9  provided with a bottom  13  is mounted on the shaft, so that the gas cap  1  and the seal cap are axially and rotationally movable relative to one another. The axial motion between a pop up and flush positions of the lid  3  is shown and explained in reference to FIGS. 2-4. In order to articulate these positions of the gas cap, the bottom  13  of the seal cap  7  has a pair of intersecting longitudinal recesses  15 ,  17  provided with different cross-sectional depths and selectively receiving the pin  11  upon axial displacement of the shaft  9 . 
     As illustrated in FIG. 2, the shaft  9  is provided with a flange  21  attached to the underside  5  and having an abutment surface  23 . The seal cap is formed with an upper flange  19  having an upper surface  25  which faces the underside  5  of the lid  3 . An interior of the seal cap  7  is recessed and includes an upper compartment  27 , a lower compartment  29  and a shaft pocket  31  which opens at opposite ends thereof into the compartments  27 ,  29 . Collectively, compartments  27 ,  29  and pocket  31  form a channel opening at opposite ends into the upper surface  5  and bottom  13  of the seal cap and traversed by the shaft  9 . 
     The lower compartment  29  formed by the recesses  15  and  17  is a two-tier compartment, in which the first tier corresponds to a depth of the shallow recess  17  (FIGS. 3,  4 ), and the second tier corresponds to a depth of the deep recess  15  (FIGS. 2,  4 ). The shallow recess  17  is deep enough to harbor the pin  11  so that the pin would not be arbitrarily able to slip off or disengage this recess. As seen in FIGS. 24, each of the recesses&#39; bottoms  14 , 16  forms an abutment surface for the pin  11  upon lodging thereof in the respective recess. 
     The shaft pocket  31  has an inner periphery which is radially adjacent to the shaft in order to prevent the upper and lower compartments  27 ,  29  from fluid intercommunication. However, the seal cap  7  is made of a fuel resistant material having a low friction coefficient which allows the shaft  9  to slide without substantial impediment between the flush and pop up positions of the gas cap  1 . The shaft pocket  31  has a cylindrical cross-section conforming to a cross-section of the shaft  9 . However, it is possible to have different cross-sections of this chamber as long as an outer periphery of the shaft  9  conforms and is in contact with an inner surface of the shaft pocket  31 . 
     The upper compartment  27  as shown in FIG. 2 may serve as an overfill cap as will be explained herebelow. A narrow channel  33 , which is recessed in a body  8  of the seal cap  7  and is spaced radially apart from the shaft pocket  31 , opens at opposite ends thereof into the upper and lower compartments  27 ,  29  respectively. This channel provides air communication and, if necessary, liquid fuel communication in case of overfilling of a gas tank  100  (FIG.  6 ). As shown in FIG. 2, only one such channel is illustrated but, in fact, it is conceivable to have the seal cap with more than just one narrow channel. The upper compartment  27  is shown to be generally annular. However, it may have different cross-sections. 
     Although the channel  33  is shown to be axial, it is conceivable to have it inclined with respect to axis A—A. The channel as illustrated opens into the deep recess  15 . However, it is possible to form this channel in such a manner that it will open into the shallow compartment  17 . The channel should have a cross-section which is sized to allow an excessive amount of fuel to pass into the upper compartment without, however, overfilling it. 
     An outer periphery of the seal cap  7  is provided with a thread  35 , which may engage a female thread formed on sleeves of existing gas filling arrangements. 
     An upper end of the shaft  9  is surrounded by a coil spring  37  which engages the abutment surface  23  of the flange  21  and the upper compartment&#39;s bottom  27 ′ by its opposite ends. The spring is selected in such a way as to exert a sufficient axial force overcoming friction between the shaft  9  and the inner periphery of the intermediate chamber  35  and to bias the lid  3  in its pop up position. 
     As shown here, the pin  11  extends through a hole  12  formed in the vicinity of the free end of the shaft  9  and somewhat spaced therefrom. The pin  11  engages the shallow recess  17  which corresponds to the flush position of the lid  3 , in which it is slightly spaced above the upper surface  25  of the seal cap  7 . 
     FIG. 3 illustrates a position of the lid  3 , which is either immediately prior to, or immediately subsequent to the flush position of the lid  3  as shown in FIG.  2 . In order to bring the lid  3  in the flush position, first an external axial force ‘A’ overcoming the spring&#39;s counterforce is applied to the lid  3  for displacing it in a position in which the pin  11  is spaced axially inwardly from the bottom  13 , as shown in FIG.  3 . Axial displacement of the lid is arrested by the upper surface  25  of the seal cap and corresponds to the position of the pin  11  shown in FIG. 3 a . Once the pin is placed outside the body  8  of the seal cap, the shaft is able to rotate upon applying a torque to the lid  3 . As a result of such rotation, the pin  11  is angularly displaced in order to be to be in alignment with the shallow recess  17 . Due to the spring&#39;s action and after removal of the external force ‘A’, the pin  11  is pulled up into the recess  17  as shown in FIG. 2. A peripheral edge  39  is machined with a textured or knurling surface which facilitates rotational engagement between a user and the lid  3 . 
     In order to bring the lid  3  in the pop up position, as shown in FIG. 4, the lid  3  is first displaced axially downwardly from the shallow recess  17  in the position illustrated in FIG.  3 . Since the lid  3  and shaft  9  are rotationally displaceable in this position with respect to the seal cap  7 , the pin  11  may be aligned with the deep recess  15  and, upon cessation of the force ‘A’, the pin is guided axially upwardly along this recess and comes into contact with the bottom  14 . Thus, the lid  3  is popped up by action of the spring  37  and is located at a distance from the upper surface  25  of the seal cap  7 . 
     The seal cap  7  is made of a fuel resistant plastic material. The rest of the shown parts including the lid, shaft and pin may be made of stainless steel or aluminum. 
     FIG. 5 represents a gas cap assembly which may be often seen on existing gas tanks of motorcycles or powerboats. The gas cap assembly has a gas cap  105  extending from an outer decorative surface  110  of a tank  100 . This decorative outer surface  110  of a gas tank may have numerous designs, for example, flames. The gas cap as shown in this figure interrupts a pattern of flames, which are decoratively imprinted on the tank, and may contribute to a less appealing design. 
     In contrast, the gas assembly according to the invention (FIG. 5A) includes the lid  3  which in its flush position as illustrated here has its upper surface  41  lying substantially in a plane of the outer surface  110  of the gas tank  100 . It is easy to see that a decorative pattern on the surface  110  is substantially uninterrupted in the flush position of the lid  3  thereby making the whole design more appealing. 
     Referring to FIG. 6 the gas assembly according to the invention includes an outer sleeve  43  formed with a mounting flange  47 . The sleeve  43  is mounted on the gas tank  100  to have its mounting flange  47  lying substantially flush with the surrounding surface  110  of the tank  100 . The sleeve further includes an inner supporting flange  55  which is juxtaposed with an inner surface  59  of the mounting flange  19  of the seal cap. In order to provide reliable engagement between these surfaces, a sealing member, for example, an elastomeric O-ring  45  (FIGS. 8-10) is inserted therebetween during an assembling operation. 
     The shaft  9  of the lid  3  is inserted in the shaft pocket  31  to sealingly engage an inner periphery thereof and is provided with the spring  37 , as is explained above. After the lid  3  has been inserted in the sleeve  43 , the hole  12  of the shaft  9  receives the pin  11  which is keyed thereto. 
     The gas cap assembly operates in a simple manner, which is illustrated in FIGS. 8-10. When the gas tank is filled, as illustrated in FIG. 8, the gas cap  1  is screwed in the sleeve  43  which is formed with a female thread  49  mating with the thread  35  of the seal cap  7 . The threaded engagement between the sleeve and the seal cap provides a reliable seal preventing fuel from leaking outside the gas tank. 
     As further shown in FIG. 8, the lid  3  is in its flush position in which the top surface  41  thereof is surrounded by the mounting flange  47  and lies substantially in the same plane. In order to fill the gas tank, the user exerts the force ‘A’ directed downwardly upon the top surface  41  of the lid  3  thereby bringing the lid and the shaft in the position of FIG. 9, in which the pin  11  disengages the shallow recess  15 . Once the pin is out of this engagement, it is sufficient to angularly displace the lid at a predetermined angle, for example a  900  angle, so that the pin is aligned with the deep recess  17 . After this alignment is brought about the lid  3  is released and, under the spring&#39;s action, it is displaced in the pop up position as illustrated in FIG.  10 . 
     Having brought the lid in its pop up position, the user may further unscrew the seal cap from its engagement with the sleeve by actuating the lid which in its pop up position is rotationally fixed with the sleeve. Once the gas cap is unscrewed the user may proceed with filling the gas tank. 
     Another embodiment of a pin arrangement is illustrated in FIG.  11  and includes a pin  91  which is mounted on a lower end of a rod  93  extending inwardly from the shaft  9 . This rod may be machined as an integral part of the shaft  9  or may be a separate part. The pin  91  has a pair of elastically deformable leaves  80 ,  90  which are forcibly pushed toward one another while being displaced through the shaft pocket  31 . Due to inherent elasticity of the leaves which are made of, for example, spring steel, the leaves tend to straighten out immediately after passing this pocket. 
     It is understood that the embodiments of the invention are not limited to the details shown and described herein but intend it cover all such changes and modifications as are encompassed by the scope of the appended claims.