Patent Publication Number: US-2007107800-A1

Title: Locking system for a closure mechanism for a fuel-tank filler pipe

Description:
The present invention relates to a locking system for a closure mechanism for a fuel-tank filler pipe.  
      Filler pipes on fuel tanks, in particular tanks on board motor vehicles, are closed off during normal use of the tank outside filling periods. Closure is generally produced by means of a cap that is inserted into the upper part of the pipe while a rotational movement is imparted to it so as to close the pipe in a liquid-tight and gas-tight manner. There are various types of cap, made of metal and/or plastic, sealing being produced by clamping a seal by screwing or by turning a key inserted into the centre of the part outside the pipe.  
      The operations of removing the cap before filling the tank and of replacing this cap and closing the pipe after filling are usually carried out manually by the user or the filling-station attendant. When the tank has been filled, the cap sometimes might not be replaced, owing to forgetfulness, thus resulting in the loss of this cap and in the pipe remaining open to the atmosphere for a relatively long time. During this period, liquid fuel losses may occur and vapour escapes in the surrounding atmosphere.  
      With the aim of preventing cap losses and the ensuing atmospheric pollution, closure systems incorporated into the filler cap have been proposed, to replace the traditional cap. Improved versions of these generally comprise blocking means for preventing said systems opening unexpectedly, for example during cleaning of the bowl (indentation in the bodywork where the filler pipe is located and that is closed off by the fuel flap) using a high-pressure cleaning device.  
      Thus, for example, application WO 03/010022 in the name of the applicant describes a closure device provided with blocking means that can be disengaged by means of a thrust force parallel to the axis of the pipe head and automatically re-engaged upon closure of the fuel flap. Such a system has the advantage of automatic locking, coupled to the closure of the flap, and of being operational even in the event of a power failure on the vehicle (since disengagement is manual, via the thrust of the dispensing nozzle). However, there is a risk that a high-pressure water jet directed substantially parallel to the axis of the pipe head may, in spite of everything, disengage the blocking means in the same way as a dispensing filler nozzle.  
      An object of the present invention is therefore to provide a simple locking system that makes it possible to overcome power failures and has the advantage of automatic locking (remedying forgetting to lock after filling), while at the same time offering a lower risk of accidental unlocking.  
      To this end, the present invention relates to a system for locking a closure mechanism for a fuel-tank filler pipe covered by a fuel flap, said mechanism comprising a shutter allowing automatic opening of the pipe via the action of a fuel-dispensing nozzle, this shutter being: 
          retractable through the action of thrust directed against it along an axis parallel to the axis of the pipe head;     integral with a return spring allowing it to be held in the closed position; said system comprising:     a lever integral with the closure mechanism and having the effect of locking/unlocking it, depending on its position;     a lever arm, integral with the fuel flap, that can act effectively on the lever only to lock the mechanism when it is unlocked and the fuel flap is being closed.        

      “Fuel tank” is intended to means any type of tank capable of storing a liquid and/or gaseous fuel under varied pressure and temperature conditions. Reference is more particularly made to tanks of the type found on motor vehicles. The term “motor vehicle” is intended to include not only cars but also motorcycles and lorries.  
      The filler pipe is a pipe that communicates with the interior of the tank and allows the introduction of fuel.  
      The tank and the pipe may be made of metal or of plastic.  
      The closure mechanism to be locked by the system according to the invention is well suited to a tank/filler-pipe assembly of which at least one of the two components of the assembly is made of plastic. It is particularly well suited to an assembly of which the filler pipe is made of plastic. Preferably, this closure system itself comprises at least one component made of plastic.  
      “Plastic” is intended to mean any material comprising at least one synthetic resin polymer.  
      All types of plastic may be suitable. Particularly suitable plastics belong to the category of thermoplastics.  
      “Thermoplastic” means any thermoplastic polymer, including thermoplastic elastomers and blends thereof. The term “polymer” denotes not only homopolymers but also copolymers (binary or ternary copolymers in particular). Examples of such copolymers are, with no restriction being implied, random copolymers, linear and other block copolymers and graft copolymers.  
      Any type of thermoplastic polymer or copolymer whose melting point is below the decomposition temperature is suitable. Synthetic thermoplastics that have a melting range spread over at least 10 degrees Celsius are particularly suitable. Examples of such materials are those that have a polydispersity of their molecular mass.  
      In particular, use may be made of polyolefins, polyvinyl halides, thermoplastic polyesters, polyketones, polyamides and copolymers thereof. A blend of polymers or copolymers may also be used, as may a mixture of polymeric materials with inorganic, organic and/or natural fillers such as, for example, but with no restriction being implied, carbon, salts and other inorganic derivatives, and natural or polymeric fibres. It is also possible to use multi-layer structures consisting of stacked, integral layers comprising at least one of the polymers or copolymers described above.  
      The aim of the closure mechanism to be locked by the system according to the invention is to perform the function of a cap that closes, in a sealed manner, the upper part of the filler pipe outside tank-filling periods with the aim of avoiding any escape and loss of liquid fuel and vapour to the atmosphere when the tank contains fuel.  
      Preferably, the closure system is incorporated into the pipe head, i.e. it is incorporated into a set of components that are mounted on the upper end of the filler pipe and form a head of which one part formed by a body covers the pipe and another part is inserted into the top of this pipe over a predetermined length.  
      The closure mechanism allows, in particular, automatic opening of the pipe via the action of a fuel-dispensing nozzle. “Automatic opening” is understood to mean opening produced by the action of the dispensing nozzle alone, to the exclusion of any other mechanical influence. The dispensing nozzle is that which equips the hoses of fuel pumps in filling stations.  
      The closure mechanism comprises a shutter, i.e. a device closing off the passage for gases and liquids in the pipe. This shutter may have various forms. A particularly suitable form is that of a movable plate that closes off the passage when it is in the closed position. This plate may optionally be coupled to a rotary casing comprising a cylindrical opening (as in application FR 03/12782, in the name of the applicant, the content of which is therefore incorporated in the present application by reference). 
    
    
      According to the invention, the shutter can be retracted through the action of a thrust directed against it along an axis parallel to the axis of the pipe head. Various means may be present in order to render the shutter retractable. One means that has yielded good results is a shaft integral with the pipe head and located at the periphery of the shutter, which can serve as rotation axis, allowing tilting of the shutter.  
      The shutter is held in the closed position by a return spring. A highly suitable spring is a torsion spring arranged around the shaft, with one end integral with the shutter.  
      According to the invention, the closure mechanism is provided with a locking system comprising a lever that, depending on its position, allows or blocks (either directly or indirectly, via coupling/securing to a supplementary component) the retraction of the shutter. Preferably, the lever is integral with a rotary or pivoting component that effectively locks/unlocks the closure mechanism, depending on its position.  
      According to a first advantageous embodiment, the lever is integral with a rotary ring that collaborates with the shutter via a bayonet system of which the parts that cooperate are arranged, respectively, on the inner cylindrical surface of the ring and over the periphery of the shutter. These parts of the bayonet device may consist of flattened lugs whose thickness varies in the form of a bevel and which are arranged inverted one on top of the other. Alternatively, a component (the ring, for example) may comprise recesses of suitable size and form to allow the passage of lugs arranged on the other component (the shutter).  
      According to this embodiment, action on the lever gives rise to the rotation of the ring and, respectively, the alignment and de-alignment (in the unlocking and locking position, respectively) of the lugs and of the recesses.  
      According to another embodiment, the lever is integral with a plate that is able to pivot about an axis parallel to the axis of the pipe head, between a position in which it blocks the movement of the shutter and a position in which it allows its retraction, the lever actuating pivoting of the plate between these two positions.  
      According to the invention, a lever arm is integral with the fuel flap and its geometry is such that it is able effectively to act on the lever in order to lock the closure mechanism (when it is unlocked) when the fuel flap is being closed (i.e. during its closing), but such that, conversely, opening of the flap does not give rise to any action on the lever and thus does not unlock the closure mechanism. Manual action (direct or indirect) is required to give rise to this unlocking.  
      “Direct manual action” is understood to mean a direct mechanical action (via the user&#39;s hand or finger(s)) on the lever in order to move it from one position to the other (locking/unlocking).  
      “Indirect manual action” is understood to mean the manual actuation of the control (push-button, switch or the like) of an actuator (for example, an electric, electromagnetic or pneumatic actuator) or a motor that acts on the lever in order to give rise to its change in position.  
      Advantageously, when an indirect manual control is used, the system is nevertheless designed to also allow direct manual control with a view to allowing the system to be locked/unlocked in the event of a power failure, also.  
      It should be noted that a sensor monitoring proper locking of the closure mechanism (and thus of the fuel flap) (indicator light or sound indication) may be incorporated into the vehicle&#39;s passenger compartment, for greater security.  
      The present invention is illustrated in a non-limiting manner by FIGS.  1  to  6 , which illustrate certain preferred embodiments of locking systems according to the invention.  
     
       FIGS. 1 and 2 
     
      These figures illustrate a pipe head provided with a closure mechanism ( 1 ) and also a fuel flap ( 2 ) in an open position. These elements are provided with a locking system comprising a lever ( 3 ) integral with a rotary ring ( 4 ) that collaborates with a shutter ( 5 ) via a bayonet system. This lever ( 3 ) slides in a slot ( 6 ) made in a cover ( 7 ). The fuel flap ( 2 ) is integral with a lever arm ( 8 ), which, in these figures, is uncoupled from the lever.  
      In  FIG. 1 , the closure mechanism is in the locked position, but the flap ( 2 ) has already been opened by the user.  
      In  FIG. 2 , the closure mechanism has been unlocked by manual action of the user (direct or indirect, via control of an actuator) on the lever ( 3 ). The shutter ( 5 ) is not visible in this case (because it is in the retracted position on account of the dispensing nozzle (not shown) in order to carry out filling of the fuel tank).  
      Locking of the closure mechanism after filling may proceed as follows: 
          either the user locks the mechanism by direct manual action on the lever     or, if the user forgets to lock, this is automatically achieved by closure of the fuel flap, which is illustrated in the following  FIGS. 3 and 4 . 
 
  FIGS. 3 and 4  
       

      These figures illustrate in more detail two embodiments of locking systems according to the invention. They illustrate certain elements already illustrated in  FIGS. 1 and 2  (and bearing the same numbers), and which are contained in/accessible via the filling bowl ( 9 ). It is also possible to see here: 
          the mechanism for retracting the shutter, which comprises a shaft ( 11 ) and a return spring ( 11 ′) for holding it in the closed position;     the bayonet system comprising a rotary ring ( 12 ) integral with the lever ( 3 ) and the actual shutter ( 5 ′) in the form of a tilting plate.        

      The locking system shown in  FIG. 3  is purely manual. It is shown in a position in which the flap ( 2 ) is in the process of reclosing and in which the lever arm ( 8 ) will abut on the lever ( 3 ) in order to lock the closure mechanism. A purely manual unlocking solution of this type has the drawback for the user of exposing the latter&#39;s hands to possible soiling and fuel residue present in the filling bowl ( 9 ).  
      The system shown in  FIG. 4  is both manual and partially controlled by an actuator ( 10 ). Via a control button located in the vehicle&#39;s passenger compartment, for example (or in the filling bowl ( 9 )), the user actuates the actuator ( 10 ) that unlocks the closure mechanism by acting on the lever ( 3 ). In the event of a power failure, it is still possible to act manually on the lever ( 3 ), but the user is normally kept free of soiling. In order to lock the mechanism after filling, it suffices to reclose the flap ( 2 ), as in  FIG. 3 .  
     
       FIGS. 5 and 6 
     
      The system illustrated in these figures is a locking system for a closure mechanism comprising a movable plate ( 5 ′) coupled to a bushel ( 5 ″) via a system of gear wheels ( 5 ′″). The plate ( 5 ′) is able to tilt (in the wake of a thrust parallel to the axis of the pipe) about a shaft ( 11 ), and is brought back into its closed position by a return spring (not shown).  
      The movement of the tilting plate ( 5 ′) may be blocked by means of a pivoting counterplate ( 12 ′) that pivots about an axis ( 13 ) and that can be placed in the locked/unlocked position by means of action on a lever ( 3 ).  
       FIG. 5  shows a section through the closure mechanism in a plane comprising the axis of the pipe, and  FIG. 6  shows a front view solely of the tilting plate part ( 5 ′)/pivoting counterplate ( 12 ′). In the latter, the mechanism is shown in the locked position and, in order to unlock it, it is necessary to act on the lever in the direction indicated by the arrow.  
      Just as in the system shown in FIGS.  1  to  4 , the fuel flap (not shown) is provided with a lever arm with a geometry and location such that it abuts on the lever ( 3 ) if the system is unlocked and the fuel flap is reclosed, this being so as to bring the lever back into the position shown in  FIGS. 5 and 6  (and thus to relock the closure mechanism).