Abstract:
A mis-fuel inhibitor in an inlet neck assembly of a vehicle fuel system discriminates between nozzle diameters, allowing entrance of nozzle diameters at or greater than a predetermined minimum diameter while inhibiting entrance of nozzles having diameters less than the predetermined minimum diameter. An actuator responsive to nozzle diameters opens and closes shutters blocking nozzle entrance.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is National Phase of International Application Number PCT/US2009/052561, filed Aug. 3, 2009, and claims benefits to U.S. Provisional Application Ser.No. 61/090,411, filed on Aug. 20, 2008. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to vehicle fuel systems and the refueling structures thereof provided to receive fuel into the vehicle fuel system. More particularly the invention relates to vehicle fuel system inlet neck assemblies having inlet openings with diameters that are larger than the nozzle diameters of refueling systems for dispensing fuels of types other than the fuel intended for the vehicle, and still more particularly to structures for preventing mis-fueling a vehicle fuel system with unintended fuels. 
     BACKGROUND OF THE INVENTION 
     It is known to provide refueling system nozzles of different sizes so that an individual operating the refueling system can be aware of the type of fuel that will be dispensed from the system, and to prevent the inadvertent deposit of a wrong fuel, such as diesel fuel, into some vehicles, such as gasoline powered automobiles. It is known, for example, to provide nozzles for dispensing diesel fuel of a larger diameter than the nozzles for dispensing gasoline or urea. Accordingly, an individual cannot inadvertently dispense diesel fuel from a diesel fuel refueling system into an automobile fuel system requiring gasoline in that an inlet opening at the inlet end of the automobile fuel system will have an opening smaller than the diameter of a diesel fuel dispensing nozzle. 
     By way of further example, a urea dispensing nozzle commonly has a diameter of 19 mm and a gasoline dispensing nozzle commonly has a diameter of 21 mm. Vehicle fuel systems intended to receive such fuels are provided with fuel system inlet openings only minimally larger than the dispensing nozzle diameter for the fuel intended. Diameters for diesel fuel refueling system dispensing nozzles intended for passenger cars and light trucks are generally between 23.6 mm and 25.5 mm, while high flow rate diesel fuel dispensing nozzles intended for heavy-duty trucks are provided in diameters of 28.5 mm to 38 mm to enable faster dispensing of larger fuel volumes. Again, the inlet openings of vehicle fuel systems intended to be refueled with diesel fuel are provided with opening diameters only minimally larger than the dispensing nozzle diameter from which it is intended to be refueled. 
     Accordingly, it can be appreciated that the nozzle for diesel fuel dispensing systems generally will not fit into the refueling inlet openings of gasoline or urea fuel systems, and it is therefore unlikely that a fuel system requiring gasoline or urea will be refueled inadvertently with diesel fuel. However, because of the larger diameters at the refueling inlet openings of diesel fuel systems, a vehicle requiring diesel fuel can be refueled inadvertently from a refueling system having a urea dispensing nozzle or a gasoline dispensing nozzle. Refueling with improper fuel can cause damage to fuel systems and engines and therefore must be avoided. 
     Some nozzle inhibiting structures are known, and can prevent a smaller nozzle from a gasoline or urea refueling system from being inserted into a refueling inlet opening for a diesel fuel system. However, some such known structures are overly complex, complicating assembly, installation or retrofitting on existing systems; as well as compromising performance reliability under some situations. Some are not completely reliable, and can be forced to admit a smaller nozzle through excessive or angular force applied when trying to insert a smaller nozzle. Accordingly a simple yet reliable structure for inhibiting inadvertent mis-fueling of diesel fuel systems is desirable. 
     SUMMARY OF THE INVENTION 
     A mis-fuel inhibitor assembly includes a removable blocking structure in front of the primary shutoff valve flapper door in the inlet neck assembly of a vehicle fuel system. The blocking structure prevents a nozzle from reaching the flapper door and opening the flapper door. An actuator adjusts a position of the blocking structure to allow passage of a refueling nozzle to the flapper door. The actuator is responsive only to nozzles of a specified diameter or larger, so that nozzles having diameters smaller than the standard nozzle for the intended fuel do not initiate the actuator to adjust the blocking structure, and a smaller nozzle is inhibited from accessing the flapper door. 
     In one aspect of one form thereof, the present invention provides a vehicle fuel system inlet inhibitor for limiting fuel nozzle access by nozzle diameter. The inhibitor has a fuel inlet path defined by a plurality of openings; first and second shutters at one of the openings having closed positions blocking passage of a refueling nozzle through the opening and opened positions allowing entrance of the refueling nozzle through the openings. An actuator is connected to the shutters for opening and closing the shutters together, the actuator being initiated to open the shutters upon insertion of a nozzle having a diameter of at least a predetermined minimum diameter 
     In another aspect of another form thereof, the present invention provides a vehicle fuel system inlet neck assembly with an inhibitor for limiting fuel nozzle access by nozzle diameter and having an inlet path defined by a plurality of openings; and a primary shutoff valve having an access hole positioned with respect to the inhibitor to receive a refueling nozzle inserted along the inlet path, and a flapper door closing the access hole. The inhibitor includes an actuator having peripherally connected segments defining one of the openings having a diameter smaller than a minimum acceptable nozzle diameter. Adjacent segments of one pair are separated by an axial separation extending through the actuator from the opening defined by the actuator segments. The opening expands under force exerted by insertion of a nozzle of at least the minimum acceptable diameter. Expansion of the opening causes movement of at least some of the segments. The actuator has first and second pins axially directed from the actuator toward the primary shutoff valve, the pins being disposed on segments that are moved by expansion of the opening. An inner plate has lateral guide slots through which the first and second pins extend. First and second shutters are disposed on an opposite side of the inner plate from the actuator and block access to the flapper door in closed positions of the shutters and expose the flapper door in opened positions of the shutters. Cam slots in the first and second shutters receive distal end portions of the first and second pins. 
     In a still further aspect of a still further form thereof, the present invention provides a vehicle fuel system refueling inlet inhibitor for limiting fuel nozzle access by nozzle diameter. The inhibitor includes an actuator having peripherally connected segments defining an opening with a diameter smaller than a minimum acceptable nozzle diameter and larger than a maximum unacceptable nozzle diameter. Segments of one pair are separated by an axial separation extending through the actuator from the opening. The opening expands under force exerted by insertion of a nozzle of at least the minimum acceptable diameter and causes movement of at least some of the segments. First and second pins extend from segments that are moved by expansion of the opening. An inner plate has lateral guide slots through which the first and second pins extend. First and second shutters are on an opposite side of the inner plate from the actuator, and have closed positions adjacent each other and opened positions in which the shutters are swung away from each other. Cam slots in the first and second shutters receive distal end portions of the first and second pins. 
     One advantage of one form of the present invention is that a mis-fuel inhibitor can be added to an inlet neck assembly of a motor vehicle fuel system to minimize the opportunities for refueling the vehicle with improper fuel. 
     Another advantage of another form of the present invention is that a refueling pump nozzle smaller than an intended refueling nozzle size can be restricted from entering a vehicle fuel system during a refueling operation. 
     Still another advantage of still another form of the invention is that common nozzle sizes for gasoline and urea refueling pumps can be inhibited from entering a diesel fuel system inlet neck assembly so that the possibility of refueling a diesel fuel system with gasoline or urea is reduced. 
     Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vehicle fuel system inlet neck assembly having a mis-fuel inhibitor therein; 
         FIG. 2  is a cross-sectional view of the fuel system inlet neck assembly shown in  FIG. 1 ; 
         FIG. 3  is an exploded view of the inlet neck assembly shown in  FIGS. 1 and 2 ; 
         FIG. 4  is a fragmentary perspective view of the inlet neck assembly shown in the previous drawings, illustrating a condition prior to refueling; 
         FIG. 5  is an end view, partially broken away, of the inlet neck assembly in the condition shown in  FIG. 4 ; 
         FIG. 6  is a fragmentary perspective view of the inlet neck assembly shown in the previous drawings, illustrating a condition as a refueling operation is commenced by initial insertion of a refueling nozzle; 
         FIG. 7  is an end view, partially broken away, of the inlet neck assembly in the condition shown in  FIG. 6 , but with the refueling nozzle not shown to more clearly reveal structures of the inlet neck assembly; 
         FIG. 8  is a cross-sectional view of the inlet neck assembly shown in the previous drawings, illustrating a condition during a refueling operation with full insertion of a refueling nozzle; 
         FIG. 9  is an end view, partially broken away, of the inlet neck assembly in the condition shown in  FIG. 8 , but with the refueling nozzle not shown to more clearly reveal structures of the inlet neck assembly; 
         FIG. 10  is a cross-sectional view of the inlet neck assembly at the end of a refueling operation, as the refueling nozzle is being removed; 
         FIG. 11  is a cross-sectional view of the inlet neck assembly with the refueling nozzle further removed than as shown in  FIG. 10 ; 
         FIG. 12  is a perspective view of an actuator in the mis-fuel inhibitor shown in the previous drawings; 
         FIG. 13  is a perspective view of an actuator inner housing in the mis-fuel inhibitor shown in the previous drawings; 
         FIG. 14  is a perspective view of an actuator outer housing in the mis-fuel inhibitor shown in the previous drawings; and 
         FIG. 15  is a perspective view of a flapper door bracket of a primary shutoff valve in the inlet neck assembly shown in the previous drawings. 
     
    
    
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now more specifically to the drawings and to  FIGS. 1 and 2  in particular, a vehicle fuel system inlet neck assembly  20  is shown having a mis-fuel inhibitor  22  as a part thereof for preventing the insertion of a refueling nozzle that is smaller in diameter than the nozzles provided for the intended fuel. Refueling system  20  is shown as a capless refueling system having a primary shutoff valve  24 ; however, those skilled in the art will readily recognize that mis-fuel inhibitor  22  can be incorporated into the inlet neck of a vehicle fuel system having an outer cap thereon as well. The capless structure shown is merely one suitable arrangement in which the mis-fuel inhibitor can be used advantageously, but is not intended to limit applications and uses of the present invention, nor the scope of the claims that follow. 
     Mis-fuel inhibitor  22  includes an outer cover  30 , an actuator  32 , an actuator inner housing  34 , first and second shutters  36 ,  38  and an actuator outer housing  40 . Actuator outer housing  40  and outer cover  30  define an inner volume in which actuator inner housing  34  is contained, with actuator  32  positioned therein and first and second shutters  36 ,  38  disposed between actuator inner housing  34  and actuator outer housing  40 . A path is defined along openings through the assembled components for insertion of a properly sized nozzle to reach primary shutoff valve  24 . As those skilled in the art will readily understand, various locating features including cooperating ribs, grooves, projections, holes and the like can be used on adjacent components for properly locating and positioning the various components with respect to one another. 
     More specifically, outer cover  30  includes a top  50  defining a circumferential channel  52  at the outer edge thereof and an upstanding ring  54  defining an opening  56  therethrough. A flange  58  at the outer edge of ring  54  provides stability and strength. Ring  54  can be shaped and sloped with respect to the angle at which inhibitor  22  is positioned to direct a refueling nozzle inserted therein. 
     Actuator  32 , shown individually in  FIG. 12 , is a generally annular, expandable structure of connected, partially enclosed, truncated pyramid-shaped segments  60 , with open bases thereof at the circumferential periphery of actuator  32 . As can be seen in  FIGS. 2 and 12 , each of the truncated pyramid-shaped segments  60  has an outer end panel  62  and an inner end panel  64  between radial panels  66  and  68 . Segments  60  taper inwardly both radially and axially, and together segments  60  define a narrowed opening  70  at rounded truncated apexes  72  of the segments  60 . Narrowed opening  70  defines an expandable passage through actuator  32 . In a relaxed state of the installed actuator  32 , opening  70  is of smaller diameter than the diameter of the smallest acceptable refueling nozzle to be received in mis-fuel inhibitor  22  and is larger than the diameter of the refueling nozzles for unacceptable fuels that are to be prevented from completely entering inlet neck assembly  20 . Outwardly closed radial spaces  74  are provided between adjacent segments  60  except for between one pair of adjacent segments  60  that are separated by a complete axial separation  76 . Outwardly closed radial spaces  74  terminate at connecting panels  78  provided at the outer periphery of actuator  32  to interconnect adjacent segments  60  at the open bases thereof. Accordingly, actuator  32  can be expanded and contracted, increasing or decreasing the width of axial separation  76  while changing the shapes of radial spaces  74  slightly. Pins  80 ,  82  are provided axially directed from the peripheral edge of the inwardly face end of actuator  32 , extending toward primary shutoff valve  24 , one such pin  80 ,  82  provided on each side of axial separation  76 . Accordingly, expansion of opening  70  and the resulting broadening of axial separation  76  cause pins  80 ,  82  to move away from one another. A C-shaped spring  84  is connected to and partially surrounds actuator  32 , and biases actuator  32  to a constricted position with separation  76  substantially closed in the relaxed state of the installed actuator  32 . Accordingly, insertion of a nozzle having a diameter greater than narrowed opening  70  requires sufficient force to overcome the biasing spring force of C-shaped spring  84 ; and, upon removal of such a nozzle, actuator  32  constricts under the biasing force of C-shaped pin  32 . 
     Inner housing  34 , shown individually in  FIG. 13 , is a generally cup-like structure having an inner plate  90  and a sidewall  92 . Inner plate  90  defines a major opening  94  for receiving a nozzle therethrough and lateral guide slots or channels  96 ,  98  for receiving pins  80 ,  82  of actuator  32 . Sidewall  92  can be substantially continuous or discontinuous as necessary and advantageous for operation of components contained therein in a compact assembly. One or more holes  100 ,  102  in inner plate  90  can be provided for receiving on or more locating projections of actuator  32 . 
     First and second shutters  36 ,  38  are pivotally installed leaf-like structures forming a barrier to the insertion of a nozzle through mis-fuel inhibitor  22 . At ends thereof, which in the exemplary embodiment are upper ends, first and second shutters  36 ,  38  have axially inwardly extending pivot projections  110 ,  112 , respectively. Each further defines a cam slot  114 ,  116 , respectively, angling downwardly and outwardly from upper positions near the pivot projections. Cam slots  114 ,  116  receive therein distal end portions of axially extending pins  80 ,  82  of actuator  32 . Accordingly, movement of axially extending pins  80 ,  82  caused by the outward expansion of actuator  32  as a refueling nozzle is inserted causes movement of the pins relative to cam slots  114 ,  116 , and results in shutters  36 ,  38  pivoting about the pivotal projections  110 ,  112  thereof from the closed positions in which the shutters are adjacent one another to opened positions in which the shutters are swung away from each other. 
     Actuator outer housing  40 , shown individually in  FIG. 14 , is a further cuplike structure having a base  120  at the inner end thereof, defining an opening  122  therethrough. Opening  122  is oriented with respect to opening  94  of inner housing  34 , opening  70  of actuator  32  and opening  56  of outer cover  30  so as to receive a refueling nozzle inserted along the path defined by the openings. Base  120  further defines holes  124 ,  126  that receive axially extending pivot projections  110 ,  112  of shutters  36 ,  38 , respectively; with shutters  36 ,  38  positioned between base  120  of actuator outer housing  40  and inner plate  90  of actuator inner housing  34 . Actuator outer housing  40  further defines a sidewall  128  having an outer edge  130  received in circumferential channel  52  of cover  30 . One or more lateral opening  132  can be used to define an exit path for fuel in the event of a failed nozzle shutoff when refueling is complete. 
     Mis-fuel inhibitor  20  is aligned with primary shutoff valve  24 , which includes a flapper door housing  140 , a flapper door bracket  142  with a flapper door  144  connected thereto by a pivot pin  146 , and a flapper door spring  148  for biasing flapper door  144  to a closed position. During a refueling operation, a refueling nozzle is admitted by force exerted against flapper door  144  moving the flapper door out of the way for final entry of the refueling nozzle. 
     Flapper door housing  140  includes an outer plate  150  defining an access hole  152  therein for receiving a refueling nozzle during a refueling operation. Flapper door housing  140  further includes a sidewall  154  configured such as at a circumferential inner edge  156  for engaging a filler neck from a fuel tank of a vehicle fuel system. 
     Flapper door bracket  142 , shown individually in  FIG. 15 , is anchored in flapper door housing  140  and provides a pivot anchor structure for flapper door  144 . Accordingly, the ends of pin  146  are received in holes  160  of anchor blocks  162 ,  164 . 
     Flapper door  144  includes a base structure  170  having a dome  172  thereon that is received in and/or against access hole  152  to close the opening therethrough. Pivot tabs  174 ,  176  define holes  178 ,  180  therein, respectively, and are secured about pivot pin  146 . 
     Chamfered and/or angular surfaces are provided throughout the assembly to facilitate and direct the insertion of a refueling nozzle. Some of these chamfered and/or angled surfaces are illustrated at  182 ,  184  and  186  in the drawings. 
     As can be appreciated from the description above in conjunction with the various drawings showing different stages of a nozzle  190  being inserted, first and second shutters  36 ,  38  initially block access to flapper door  144 , as shown in  FIGS. 1 ,  2 ,  4  and  5 . Axial force against shutters  36 ,  38  does not move the shutters from the closed, block positions of the installed assembly. Upon the insertion of a nozzle  190  of at least the minimum acceptable diameter, shutters  36 ,  38  are pivoted by actuator  32  about the pivot projections  110 ,  112  thereof to rotate the bodies of shutters  36 ,  38  from in front of flapper door  144 . Rotation of shutters  36 ,  38  is caused by the expansion of actuator  32  and the resulting movement of actuator pins  80 ,  82  in cam slots  114 ,  116 . 
     A refueling nozzle having a diameter smaller than the diameter required to expand actuator  32  simply passes through opening  56  and narrowed opening  70  without moving segments  60 . The nozzle can continue through major opening  94  of inner housing  34  but then encounters first and second shutters  36 ,  38  which have not been moved and remain in a blocking position relative to opening  122  and structures there beyond, including flapper door dome  172 . The nozzle cannot progress beyond this point and it never reaches primary shutoff valve  24 . Attempts to force the end of the nozzle against shutters  36 ,  38  will not move the shutters, which must rotate about their pivot projections  110 ,  112  to be moved. Further, the relationships between actuator pins  80 ,  82 ; lateral guide slots  96 ,  98  and cam slots  114 ,  116  require that all moving parts be moved together; and C-shaped spring  84  holds the actuator in a constricted position with actuator pins  80 ,  82  closely positioned one to another. Accordingly, if actuator  32  is constructed so that narrowed opening  70  requires expansion to admit a diesel fuel nozzle but not for admitting narrower nozzles typically provided for gasoline or urea refueling systems, the narrower nozzles can not be inserted beyond first and second shutters  36 ,  38 . The primary shutoff valve  24  remains closed, and inappropriate fuel is not admitted to the fuel system. 
     As illustrated in the series of drawings including  FIGS. 6-10 , if a nozzle of larger diameter, such as diesel fuel nozzle  190  is inserted through opening  56  in outer cover  30 , the end of the nozzle will encounter outer panels  62  of segments  60  in actuator  32 . Since the nozzle  190  is of a diameter larger than narrowed opening  70 , force is applied against segments  60  as the nozzle, is pushed inwardly. The tapering orientation of the outer panels  62  facilitates insertion of the nozzle being forced there against and initiation of actuator  32  by the outward movement of the segments  60 . Force applied against segments  60  and the resulting outward movement of the segments causes separation of the confronting edges along axial separation  76 . Accordingly, pins  80  and  82  are caused to move away from one another. Anchoring some of the segments  60  diametrically opposite to axial separation  76  by locating pins received in holes  100 ,  102  minimizes movement of the anchored segments and focuses the expansion of actuator  32  and segment movement to the segments most closely adjacent to axial separation  76 . Accordingly, a relatively small increase in the diameter of narrowed opening  70  results in appreciable movement of actuator pins  80 ,  82 . The relative sizes, positions and orientations of the segments  60  with respect to one another also can be used to achieve the desired movement of actuator pins  80 ,  82 . As shown in the exemplary embodiment in the drawings, not all segments  60  need be of the same size. 
     As narrowed opening  70  is caused to expand under the force from nozzle  190  being inserted, actuator pins  80 ,  82  move laterally within lateral guide slots or channels  96 ,  98 . Pins  80 ,  82  also move along cam slots  114 ,  116  of first and second shutters  36 ,  38 . As pins  80 ,  82  move along cam slots  114 ,  116 , the angular orientation of cam slots  114 ,  160  causes a swinging type movement of shutters  36 ,  38  about the pivots defined by pivot projections  110 ,  112  pivotally held in holes  124 ,  126  of actuator outer housing  40 . The swinging movement of first and second shutters  36 ,  38  exposes flapper door  144  to the continued inward advancement of nozzle  190  which, after passing through and expanding actuator  32  continues through the expanded opening in the actuator, major opening  94  of actuator inner housing  34  and between the outwardly swung first and second shutters  36 ,  38 . The end of nozzle  190  passes through opening  122  of actuator outer housing  40  and encounters flapper door  144 . Continued insertion of nozzle  190  applies force against flapper door  144 , causing the flapper door to pivot about the axis defined by pivot pin  146 . With the nozzle fully inserted into primary shutoff valve  22 , refueling can commence. 
       FIGS. 6 and 7  illustrate a condition of assembly  20  when nozzle  190  has been inserted into actuator  32 , but not fully into primary shutoff valve  24 . Nozzle  190  has caused actuator  32  to reach maximum expansion, causing shutters  36 ,  38  to be pivoted from the blocking position in front of flapper door  144 . The flapper door remains closed until contacted and moved by further insertion of nozzle  190 . 
       FIGS. 8 and 9  illustrate a condition of assembly  20  when nozzle  190  has been inserted through mis-fuel inhibitor  22  to a fully inserted position in primary shutoff valve  24  for refueling to commence. Actuator  32  remains expanded, shutters  36 ,  38  remain pivoted to opened positions and flapper door  144  has been opened by the insertion of nozzle  190 . 
     When refueling is completed, withdrawal of nozzle  190  results in flapper door  144  being urged closed by flapper door spring  148  after the end of nozzle  190  is withdrawn outwardly of access hole  152 . As nozzle  190  is removed from actuator  32 , C-shaped spring  84  urges constriction of the actuator, narrowing any gap along axial separation  76 . As actuator  32  constricts, pins  80 ,  82  move toward one another, returning along lateral guide slots  96 ,  98 . As the distal portions of pins  80 ,  82  move toward one another the pins also move along cam slots  114 ,  116  of first and second shutters  36 ,  38 . The shutters are moved toward the closed position, again concealing or blocking flapper door  144 . 
       FIGS. 10 and 11  illustrate conditions of assembly  20  when nozzle  190  is partially removed from primary shutoff valve  24  ( FIG. 10 ) and when nozzle  190  has been fully removed from primary shutoff valve  24  but remains in mis-fuel inhibitor  22 . The conditions of the various structures at stages of removal are the same as when the nozzle is in a corresponding position during nozzle insertion.  FIGS. 10 and 11  illustrate that flapper door  144  rests against and follows the movement of the end of nozzle  190  as the nozzle is either inserted or withdrawn. 
     Accordingly, structure is provided to allow the insertion of nozzles having diameters at or above the required minimum diameter, while excluding nozzles having smaller diameters. The structure will not open to allow a smaller nozzle to enter even if force is applied against some, but not all of the segments  60 . Lateral guide slots or channels  96 ,  98  of actuator inner housing  34  retain actuator pins  80 ,  82  and thereby shutters  36 ,  38  in their closed positions if force is applied generally against upper and lower segments  60  relative to the installed position as shown in the drawings. Force against upper segments  60  additionally causes actuator pins  80 ,  82  to engage against the ends of cam slots  114 ,  116 , further holding shutters  36 ,  38  in closed positions. Force applied primarily against segments  60  to the left or right causes binding of one or the other actuator pin  80 ,  82  at the end of the respective lateral guide slot or channel  96  or  98  in which it is held. Movement of shutters  36 ,  38  requires that multidirectional forces be applied simultaneously against segments  60  all around actuator  32 . The required multi-directional forces are applied when a nozzle of a diameter larger than narrowed opening  70  is inserted, but are not achieved if a nozzle smaller than narrowed opening  60  is inserted, even if the smaller nozzle is forced against some of the segments  60 . 
     In the exemplary embodiment shown, the inlet path defined by the various openings through the outer cover, actuator, actuator inner housing and actuator outer housing as well as through the primary shutoff valve is not centered to accommodate a smaller overall package. However, it should be understood that the various openings can be centered along an axis of the assembly as well. 
     Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 
     Various features of the invention are set forth in the following claims.