Abstract:
A fluid delivery system for delivering a supply of a fluid from a fluid source to at least one fuel injector includes a rail for conveying a fluid and being positionable proximate the fuel injector. The rail has a fluid passageway defined therein, the fluid passageway being in fluid communication with the source of fluid. A connector is in fluid communication with both the rail and with the fuel injector for fluidly connecting the rail to the fuel injector. The connector is universally shiftable in three orthogonal axes for accommodating static tolerances existing between the rail and the fuel injector and for accommodating dynamic relative motion between the rail and the fuel injector.

Description:
RELATED APPLICATIONS 
     The present application claims the benefit of U.S. Provisional Application Ser. No. 60/153,396, filed Sep. 10, 1999, incorporated herein in its entirety by reference. 
    
    
     TECHNICAL FIELD 
     The present invention concerns fluid rail assemblies for fuel injected internal combustion engines. More particularly, the present invention relates to a fluid rail assembly for use with a hydraulically actuated, electronically controlled fuel injector. 
     BACKGROUND OF THE INVENTION 
     Certain fuel injectors can be described as hydraulically actuated, electronically controlled. Hydraulic actuation of the fuel injector is preferably effected by engine oil at an elevated pressure. It should be understood that other fluids self contained in the vehicle powered by the internal combustion engine could also be used for hydraulic actuation of the fuel injector, including brake fluid, power steering fluid, or the like. 
     An exemplary fuel injector of this type is depicted generally in prior art FIG. 1 at  200 . A hydraulically-actuated, electronically-controlled, unit injector (HEUI), of the type described in U.S. Pat. No. 5,181,494 and in SAE Technical Paper Series 930270, HEUI— A New Direction for Diesel Engine Fuel Systems , S. F. Glassey, at al, Mar. 1-5, 1993, which are incorporated herein by reference, is depicted in prior art FIG.  1 . HEUI (injector)  200  consists of four main components: (1) control valve  202 ; (2) intensifier  204 ; (3) nozzle  206 ; and (4) injector housing  208 . 
     The purpose of the control valve  202  is to initiate and end the injection process. Control valve  202  is comprised of a poppet valve  210 , electric control  212 , having an armature and solenoid. High pressure actuating oil is supplied to the valve&#39;s lower seat  214  through oil passageway  216 . To begin injection, the solenoid of the electric control  212  is energized moving the poppet valve  210  upward the lower seat  214  to the upper seat  218 . This action admits high pressure oil to the spring cavity  220  and the passage  222  to the intensifier  204 . Injection continues until the solenoid of the electric control  212  is de-energized and the poppet  210  moves from the upper seat  218  to lower seat  214 . Actuating oil and fuel pressure decrease as spent actuating oil is ejected from the injector  200  through the open upper seat oil discharge  224  to the valve cover area of the internal combustion engine, which is at ambient pressure. 
     The middle segment of the injector  200  consists of the hydraulic intensifier piston  236 , the plunger  228 , fuel chamber  230 , and the plunger return spring  232 . 
     Intensification of the fuel pressure to desired injection pressure levels is accomplished by the ratio of areas between the upper surface  234  of the intensifier piston  236  and the lower surface  238  of the plunger  228 , typically about 7:1. The intensification ratio can be tailored to achieve desired injection characteristics. Fuel is admitted to chamber  230  through passageway  240  past check valve  242  from an external fuel supply. 
     Injection begins as high pressure actuating oil is supplied to the upper surface  234  of the intensifier piston  236  via passageway  222 . As the piston  236  and the plunger  228  move downward, the pressure of the fuel in the chamber  230  below the plunger  228  rises. High pressure fuel then flows in passageway  244  past check valve  246  to act upward on needle valve surface  248 . The upward force opens needle valve  250  and fuel is discharged from orifice  252  against the bias of return spring  256 . The piston  236  continues to move downward until the solenoid of the electric control  212  is de-energized, causing the poppet valve  210  to return to the lower seat  214  under the force of spring  220 , blocking oil flow. The plunger return spring  232  then returns the piston  236  and plunger  228  to their initial upward inactive positions, as depicted in FIG.  4 . As the plunger  228  returns, the plunger  228  draws replenishing fuel into the fuel chamber  230  across ball check valve  242 . 
     The nozzle  206  is typical of other diesel fuel system nozzles. The valve-closed-orifice style is shown, although a mini-sac version of the tip is also available. Fuel is supplied to the nozzle orifice  252  through internal passages. As fuel pressure increases, the nozzle needle  250  lifts from the lower seat  254  (as described above) allowing injection to occur. As fuel pressure decreases at the end of injection, the spring  256  returns the needle  250  to its closed position seated on the lower seat  254 . 
     The fuel injector  200  uses the hydraulic energy of pressurized actuating fluid, in this case engine oil, to cause injection. The pressure of the incoming oil controls the downward speed of the intensifier piston  236  and plunger  228  movement, and therefore, the rate of fuel injection. The amount of fuel injected is determined by the duration of a signal keeping the solenoid of the electric control  212  energized. As long as the solenoid is energized and the poppet valve  210  is off its seat, the actuating fluid continues to push down the intensifier piston  236  and plunger  228  until the intensifier piston  236  reaches the bottom of its bore. 
     A similar hydraulically-actuated unit injector  200  is described in SAE paper No. 1999-01-0196, “Application of Digital Valve Technology to Diesel Fuel Injection” and U.S. Pat. No. 5,720,261. In this injector, the poppet control valve  202  of the HEUI injector  200  has been replaced by a spool type digital control valve which is controlled by two solenoid coils, the valve spool being the armature. 
     In either case, there is a need for delivery of the high pressure volume of actuating fluid to the fuel injector  200  in order to effect the fuel injection event as described above. Actuating fluid delivery must be accomplished while allowing for tolerance stack-ups and relative mechanical motion existing between the apparatus delivering the actuating fluid and the fuel injector  200 . Tolerance stack-ups impose a considerable constraint on the design of any apparatus for delivering actuating fluid to a fuel injector  200 . The injector  200 , cylinder head, actuating fluid rail, and the connecting mechanism between the rail and the injector  200  all have tolerances associated with them. A desirable delivery mechanism is one that imposes no stress forces on the injector  200  as a result of the aforementioned tolerances and of the aforementioned relative motion. The delivery mechanism should additionally be easily connectable to the injector  200 . 
     U.S. Pat. No. 4,996,962, issued Mar. 5, 1991, discloses a fuel delivery rail assembly. The &#39;962 assembly uses sockets affixed to the tops of the fuel injectors. Plastic rail tubes extending between the sockets provide flexible engagements. The &#39;962 patent asserts that with such flexible engagements there is no need of strict limitation about a dimensional accuracy or geometrical orientation of the parts. It should be noted that while it is claimed that the flexible plastic rail tubes solve some of the problems sought to be solved by the present invention, there is no structure or teaching in the &#39;962 patent that relates to the present invention. 
     SUMMARY OF THE INVENTION 
     The actuating fluid delivery system of the present invention substantially meets the aforementioned needs of the industry. The connector assembly of the present invention that extends between the rail assembly and the fuel injector accommodates the aforementioned tolerances by being movable in three orthogonal dimensions. Further, after installation, relative motion existing between the rail assembly and the fuel injector is further accommodated by the ability of the connector assembly to accommodate such motion by being shiftable in the three dimensions. This is enabled by providing rotatability between the delivery system connector and the fuel injector. The ability of certain connector components to rotate relative to the fuel injector in at least a plane that is disposed orthogonal to a longitudinal axis enables both a shifting in the plane and a translation along the longitudinal axis. When rotation is able to occur, then the shifting and translation is able to occur. Additionally, the present invention provides for an exceedingly short path for the actuating fluid to travel from the rail assembly to the fuel injector. In the present invention, it is desirable that the L/D 2  ratio for the connector assembly be less than one. The present invention is less than 70 mm in length and satisfies the aforementioned L/D 2  ratio . Further, the connector assembly of the actuating fluid delivery system of the present invention is disposable in the limited space defined between the rocker arms of the head of the internal combustion engine. 
     The present invention includes several embodiments that provide for ease in connecting the connector assembly to the exemplary injector. An embodiment provides for a snap fit by pressing the connector onto a receiver assembly that is coupled to the injector. A further embodiment provides for a threaded engagement with the receiver assembly. 
     The present invention is a fluid delivery system for delivering a supply of a fluid from a fluid source to a fuel injector and includes a rail for conveying a fluid, the rail being positionable proximate the fuel injector. The rail has a fluid passageway defined therein, the fluid passageway being in fluid communication with the source of fluid. A connector is in fluid communication with both the rail and with the fuel injector for fluidly connecting the rail to the fuel injector. The connector is moveable in three orthogonally disposed axes for accommodating static tolerances existing between the rail and the fuel injector and for accommodating dynamic relative motion between the rail and the fuel injector such that stresses imposed on the fuel injector resulting from being fluidly connected to the rail are substantially eliminated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of an exemplary prior art fuel injector; 
     FIG. 2 is a sectional view of the connection assembly of the actuating fluid delivery system of the present invention viewed along the axis of the rail assembly; 
     FIG. 3 is a perspective view of an alternative embodiment of the connector assembly of the present invention; 
     FIG. 4 is a top view of the connector assembly of FIG. 3; 
     FIG. 5 is a sectional view of the connector assembly of FIG. 3; 
     FIG. 6 is a sectional view of a receiver assembly coupled to a fuel injection and adapted to receive the connector assembly depicted in FIGS. 3-5; 
     FIG. 7 is an alternate embodiment of the connector assembly depicted in FIGS. 3-5; 
     FIG. 8 is an alternative embodiment of the actuating fluid delivery system of the present invention, the view taken end on with respect to the rail assembly; 
     FIG. 9 is a side elevational view of an alternative embodiment of the connector assembly and receiver assembly with portions thereof broken away; 
     FIG. 9 a  is a downward planform view of the device of FIG. 9 taken at a horizontal section line  9   a — 9   a;    
     FIG. 10 is a perspective view of the mating portion of the connector assembly depicted in FIG. 9 adapted for mating with the receiver assembly; and 
     FIG. 11 is a perspective view as depicted in FIG. 10 with the ferrule removed. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The actuating fluid delivery system of the present invention is shown generally at  10  in the figures. In FIG. 2, the actuating fluid delivery system  10  is depicted coupled to an exemplary fuel injector  200  of the types described above with reference to the prior art. It is understood that the fuel injectors  200  are exemplary only and other hydraulically-actuated fuel injectors may be utilized with the actuating fluid delivery system  10 . 
     The actuating fluid delivery system  10  has two major components: rail assembly  12  and connector assembly  14 . Delivery system  10  may be directly coupled to the injector  200  or may be coupled to the injector  10  by means of a receiver assembly  15 , as depicted in FIGS. 2 and 5, that mounts on the injector  200 . 
     The rail assembly  12  includes two major subcomponents, an elongate rail  16  and cross-drilled sleeve  18 . The elongate rail  16  is preferably positioned immediately above a row of fuel injectors disposed in an engine cylinder head and has a fluid passageway  17  defined therein. For an in-line engine, a single rail assembly  12  is positioned above the row of fuel injectors with a connector assembly  14  connecting the elongate rail  16  to each of the fuel injectors  200 , e.g., six connector assemblies  14 , for an inline six engine. For a V-configuration engine, a pair of rail assemblies  12  respectively service each of the two banks of cylinders, e.g., two rail assemblies  12  each with four connector assemblies  14  for a V8 engine. Each of the elongate rails  16  is fluidly coupled to a source of high pressure actuating fluid which is preferably engine lubricating oil and may reach pressures on the order of 3500 psi. 
     A pair of relatively large bores  22 ,  24  are defined in the elongate rail  16  proximate each of the fuel injectors to be serviced. Each of the bores  22 ,  24  are in registry along an axis (longitudinal axis  74 ) that is preferably transverse to the longitudinal axis of the elongate rail  16 . The elongate rail  16  may be fixedly coupled to the cylinder head of the engine or to a rail carrier attached thereto by a plurality of straps that are fastened to the cylinder head or carrier as by bolts or studs. 
     The cross-drilled sleeve  18  of the rail assembly  12  of the actuating fluid delivery system  10  is comprised of a sleeve cylinder  40 . The sleeve cylinder  40  is closely received within the bores  22 ,  24  of the rail assembly  12 . Sleeve cylinder  40  has an upper projection  42 . A plane defined by the upper margin  43  of the upper projection  42  is preferably tangential with the exterior surface of the elongate rail  16 , thereby defining a flush fitting  44  at the point of tangency. The intersection of the sleeve cylinder  40  with the bore  22  is preferably welded or brazed to define a fluid tight intersection between the sleeve cylinder  40  and the bore  22  of the elongate rail  16 . 
     The sleeve cylinder  40  has an opposed lower projection  46  that is similar in construction to the upper projection  42  described above. The intersection of the lower projection  46  with the bore  24  is preferably welded to define a fluid tight intersection. The lower projection  46  forms a flush fitting at the point of tangency of the lower margin  49  of the lower projection  46  with the exterior surface of the elongate rail  16 . Accordingly, the longitudinal dimension of the sleeve cylinder  40  is substantially equal to the exterior diameter of the elongate rail  16 . 
     The sleeve cylinder  40  has a cylindrical bore  57  defined through the wall of the cylinder  40 . The cylindrical bore  57  presents an inwardly directed, decreasing diameter, beveled surface  50  extending upward from the lower margin  49 . The sleeve cylinder  40  has a plurality of cross drilled bores  52  preferably equi-angularly spaced around the circumference of the sleeve cylinder  40 . In the sectional depiction of FIG. 2, two opposed cross drilled bores  52  of the plurality of bores  52  are depicted. The bores  52  are in fluid communication with the fluid passageway  17 . The cylindrical bore  57  presents an undercut surface  54  proximate the cross drilled bores  52 . The undercut surface  54  defines in-part an annular fluid passageway  56 . This annular fluid passageway  56  is in fluid communication with the fluid passageway  17  via the bores  52 . 
     The connector assembly  14  of the actuating fluid delivery system  10  includes three major subcomponents: upper collar  58 , central tube  60 , and lower collar  62 . 
     The upper collar  58  of the connector assembly  14  includes a collar body  64 . The collar body  64  has a domed top surface  66 . An annular groove  68  is defined proximate the domed top surface  66 . A ring seal  72  is disposed within the annular groove  68  to define a fluid tight seal between the collar body  64  and the cylinder bore  57  of the sleeve  18 . The collar body  64  has a longitudinal Z axis that is coincident with Z axis (longitudinal axis)  74  and that further is coincident with the longitudinal axis of the sleeve cylinder  40 . The collar body  64  of the upper collar  58  presents a generally flat bottom face  76 . It should be noted that the bottom face  76  is preferably spaced apart from the lower collar  62  to accommodate relative motion between upper collar  58  and lower collar  62  along the Z axis  74 . 
     An annulus  78  is defined around the collar body  64 . The annulus  78 , in cooperation with the undercut  74  defined in the cylinder bore  57  of the sleeve cylinder  40 , defines the annular fluid passageway  56 . A plurality of connecting bores  80  extend inward from the annular fluid passageway  56 . Two opposed connecting bores  80  of the plurality of connecting bores  80  are depicted in FIG.  2 . The connecting bores  80  are fluidly coupled to an axial bore  82  defined along the Z axis  74  of the collar body  64 . The axial bore  82  has a generally semi-spherical bore expansion comprising a socket  84 . Socket  84  is spherical except at the points of intersection with the axial bore  82 . A circumferential groove is partially defined by a shelf  86  in the socket  84  at the point of its greatest circumference and by an upper ferrule  89  which is press fit into the collar body  64  and which defines the remainder or lower portion of the socket  84 . A ring seal  88  is disposed within the groove so defined to effect a fluid tight seal between the upper collar  58  and the central tube  60 . An opening  90  is defined in the flat bottom face  76  of the upper ferrule  89 . The opening  90  opens to the axial bore  82 . 
     The central tube  60  of the connector assembly  14  includes a tube body  92 . The tube body  92  has a tubular center portion  94 , an upper spherical end, comprising a ball  96 , and a lower spherical end, comprising a ball  98 . The balls  96 ,  98  may be formed integral with the tubular center portion  94 , as depicted in FIG. 2, or separately, as depicted in FIG.  5 . Further, the tube center portion  94  may function adequately to minimize static and dynamic stresses with only a single ball and socket, such as ball  96  and socket  84 , in cooperation with another suitable coupling (not shown) to the injector  200 , such as a ferrule in compressive sealing engagement with tube  94 . An axial bore  100  is defined along the Z axis  74 . The axial bore  100  is fluidly connected to the upper portion of the axial bore  82  defined in the collar body  64 . 
     In assembly, the upper ball  96  of the tube body  92  is placed into the socket  84  of the collar body  64 , the ring seal  88  is installed in the socket and the upper ferrule  89  is press fit to retain the upper ball  96  in the collar body  64 . The bore  90  in the upper ferrule  89  is somewhat greater in diameter than the exterior diameter of the tubular center portion  94  of the tube body  92  to define a gap  101  therebetween. The gap  101  accommodates relative motion in the X, Y planes (the X, Y planes being disposed orthogonal both to themselves and to Z axis  74 ) between the upper collar  58  and the tube  60 . 
     The lower collar  62  of the connector assembly  14  includes a lower ferrule  102 . The ferrule  102  has a generally flat top surface  104 . As previously indicated, the flat top surface  104  is spaced apart from the flat bottom face  76  of the collar body  64 . As will be seen, such spacing accommodates in part relative motion between the fuel injector  200  and the actuating fluid delivery system  10 . 
     An opening  106  defined in the flat top face  104  opens to an axial bore  108  defined in the lower ferrule  102 . The axial bore  108  is preferably coaxial with the Z axis  74 . The axial bore  108  has an upper portion  109  that expands downwardly into socket  110 . The receiver  15  necks down and is provided with external threads at its lower end for threaded securement in a threaded bore  114  in the injector body  200 . The injector  200  has a relatively slender fluid passageway  112  defined in the receiver assembly  15  which effectively comprises a portion of the axial bore  108  extends downward from the socket  110  to fluidly couple the connector assembly  14  of the actuating fluid delivery system  10  to the fuel injector  200 . The receiver assembly  15  has an upwardly directed aperture  117 , the aperture  117  being designed to receive the ball  98  and the lower ferrule  102  therein. The lower ferrule  102  is threadedly engageable with the receiver assembly  15  by threads  118  formed in the lower exterior margin of the lower ferrule  102 . An annular groove  120  is defined between the lower ferrule  102  and the receiver assembly  15  at the point of the greater circumference of socket  110 . A ring seal  122  is disposed within the annular groove  120 , thereby creating a fluid tight seal between the lower ferrule  102 , the receiver assembly  15 , and the exterior surface of the ball  98  of the tube  60 . 
     The diameter of the upper portion  109  of the axial bore  108  is somewhat greater than the diameter of the exterior surface of the center portion  94  of the tube  60 , thus generating a gap  124  between the lower collar  62  and the tube  60 . The gap  124  accommodate relative motion in the X, Y plane between the lower collar  62  and the tube  60 . 
     The connector assembly  14  is assembled by pressing the upper ball  96  of the tube  60  into the socket  84  of the upper collar  58  and pressing the lower ball  98  of the tube  60  into the socket  110  of the lower collar  62 . The balls  96 ,  98  are free to rotate within the respective sockets  84 ,  110 . The connector assembly  14  may then be fixedly, sealingly joined to the fuel injector  200  by threading the lower collar  62  by means of threads  118  into receiver assembly  15 , coupled to the fuel injector  200 . 
     The rail assembly  12  is then joined to the connector assembly  14 . This is accomplished by inserting the upper collar  58  into the cylindrical bore  57  of the cross drilled sleeve  18 . Initial passage of the upper collar  58  into bore  57  is directed and centered by the beveled surface  50 . When the rail assembly  12  is in place, suitable clamps are secured to the head of the engine. The upper collar  58  is slidable within the cylindrical bore  57  after assembly and while the delivery system  10  is coupled to the injector  200  in order to accommodate static tolerance stack-up between the actuating fluid delivery system  10  and injector  200  in the dimension of the Z axis  74 . 
     In this static relationship of the actuating fluid delivery system  10  to the injector  200 , substantially no stress is imposed on the injector  200  as a result of the aforementioned slidability in the Z dimension  74  and additionally as a result of the ability of the upper collar  58  and the lower collar  62  to shift in the X, Y plane relative to the tube  60 , providing for three dimensional shiftability. Such shifting in the X, Y plane is effectively a ball and socket type shifting resulting from the rotational motion of the ball  96  of the tube body  92  within the substantially spherical socket  84  of the upper collar and the rotation of the ball  98  of the tube body  92  within the substantially spherical socket  110  of the lower collar  62 . The upper collar  58  is at all times free to translate in the Z axis  74  with respect to the cross drilled sleeve  18  in order to eliminate any potential stress in the Z axis  74 . Accordingly, the delivery system  10  has three dimensional degrees of freedom of motion, as well as three rotational degrees of freedom of motion, when coupled to the injector  200 . Such freedom of motion in both static and dynamic conditions is achieved as well as when only an upper ball  96  disposed in a socket  84  is utilized in conjunction with Z axis  74  translation. 
     Subsequent dynamic motion of the actuating fluid delivery system  10  with respect to the fuel injector  200  maybe caused, for example, by the vibration of engine operation and by expansion and contraction of the various components due to heating and cooling and the like. The dynamic motion is similarly accounted for in the X, Y and Z axes as previously described with reference to the static tolerance stack-up. Relative motion of the actuating fluid delivery system  10  with respect to the injector  200  is accommodated by freedom to move enough in the X, Y, and Z axes to accommodate substantially all of the dynamic motion that occurs between the delivery system  10  and the injector  200  during operation of the engine. This is enabled by providing rotatability between the delivery system connector and the fuel injector. The ability of certain connector components (as noted above) to rotate relative to the fuel injector in at least a plane that is disposed orthogonal to a longitudinal axis enables both a shifting in the plane and a translation along the longitudinal axis. When rotation is able to occur, then the shifting and translation is able to occur. Accordingly, in both a static situation and a dynamic situation, virtually no stresses are imposed on the fuel injector  200  by the delivery system  10  as a result of the ability of the connector assembly  14  to move three dimensionally in the X, Y and Z axes. 
     During fuel injection, for delivery of an actuating fluid to the fuel injector  200 , high pressure fluid flows from the source of high pressure fluid  20  through the elongate rail  16 . Fluid passes through the cross drilled bores  52  of the cross drilled sleeve  18  into the annular fluid passageway  56 . The annular fluid passageway is fluidly connected to the connecting bores  80 . Fluid flows through the connecting bores  80  to the axial bore  82  of the upper collar  58 . The actuating fluid then flows through the axial bore  100  of the tube body  92  to the fluid passageway  112  defined in the lower collar  62 . The actuating fluid then flows to the fuel injector  200  for controlling the injection event as described above in relation to the prior art. 
     Referring to FIGS. 3-5, an alternative preferred embodiment of the connector assembly  14  is depicted wherein like reference numbers denote like components. It is understood that connector assembly  14  is to be slidably engaged with an elongate rail  16  substantially as described with respect to FIG.  2 . The connector assembly  14  of FIGS. 3-5 differs in several features with respect to the connector assembly  14  of FIG.  2 . The embodiment of FIGS. 3-5 includes an upper ferrule  134  disposed in an aperture defined between the upper spherical end  96  and the inner margin  135  of the slider collar  58 . The upper margin of the ferrule  134  bears on the ring seal  88 , holding the ring seal  88  in place to establish a fluid tight seal between the upper spherical end  96  and the inner margin  135  of the slider collar  58 . 
     The upper ferrule  134  is held in place by a snap ring  136  and is disposed generally circumferential to the tube  60  in an annular groove  138  defined in the inner margin  135  of the slider collar  58 . The snap ring  136  is radially compressible so that the snap ring  136  may be inserted into the entry aperture  140  defined at the lower margin of the slider collar  58 . The snap ring  136  is radially compressed by forcing the snap ring  136  upward through the chamfered mouth  139  to the entry aperture  140 . The entry aperture  140  is generally concentric with the tube  60 . The snap ring  136  is released from radial compression after passing through the entry aperture  140 . Such release causes the snap ring  136  to expand into the groove  138 , thereby holding the snap ring  136  in place. 
     The connector assembly  14  of FIGS. 3-5 further includes a lock nut  141 . A lower ferrule  142  is disposed generally concentric with the tube  60  and abutting an interior underside margin  144  of the lock nut  141 . The lock nut  141  has a bore  146  defined therein. The bore  146  is in sliding engagement with the exterior surface of the tube  60 . In the embodiment of FIGS. 3-5, the lower spherical end  98  is formed separate from the tube  60 , such that the lock nut  141  and lower ferrule  142  are slid up over the exterior surface of the tube  60  prior to the lower spherical end  98  being slid onto the exterior surface of the tube  60 . A generally L-shaped receiver aperture  148  is defined between respective portions of the exterior surface of the lower spherical end  98 , the exterior margin of the lower ferrule  142 , and the inner margin  149  of the lock nut  141 . Receiver threads  150  are defined over a portion of the inner margin  149  of the lock nut  141 . 
     Referring to FIG. 6, the receiver  15  has a receiver body  121 . The receiver body  121  is fixedly coupled to the exemplary fuel injector  200  by a plurality of cap screws, two cap screws  123  being depicted in FIG. 6. A centrally defined actuating fluid passageway  125  extends through the receiver body  121  and into the fuel injector  200 . The actuating fluid passageway  125  is fluidly coupled to the axial fluid bore  100  defined in the tube  60 . The actuating fluid passageway  125  comprises the final fluid coupling between the actuating fluid delivery system  10  of the present invention and the fuel injector  200 . 
     A generally funnel shaped ball receiver  126  is defined interior to the receiver body  121 . The ball receiver  126  has a generally spherical face  127  for receiving the lower spherical ball end  98  therein. A radially outward step  128  is provided at the upper margin of the spherical face  127  to partially define a groove to receive a seal ring  122  upon assembly. The exterior surface of the receiver body  121  has a plurality of threads  129  defined therein. 
     As can be seen in reference to FIGS. 5 and 6, in assembly, the receiver threads  150  of the lock nut  141  are threadedly engaged with the threads  129  of the receiver assembly  15 . The upper portion of the receiver assembly  15  projects into and substantially fills the receiver aperture  148 . As the lock nut  141  is turned down onto the receiver assembly  15 , the lower ferrule  142  extends in relatively close fit inside the inner margin  131  of the receiver body  121 , until the interior underside margin  144  of the lock nut  141  contacts the nut stop end surface  132  of the receiver body  121 , thus compressing the seal ring  122  between the ferrule  142 , the shelf  128  of the receiver body  121 , and the exterior surface of the lower spherical end  98  to create a fluid tight seal. 
     FIG. 7 is a variation on the previously described embodiment of the actuating fluid delivery system  10  of FIGS. 3-5. In the embodiment of FIG. 7, the entry aperture  140  defined in the slider collar  58  is chamfered to present a chamfered entry aperture  152 . The lock nut  141  includes a generally circular standoff  154  formed integral with the lock nut  141  and presented on the upper margin thereof. The circumference of the outer margin  155  of the standoff  154  is slightly less than the minimum inside circumference of the chamfered entry aperture  152 . In assembly, the snap ring  135  is positioned around the tube  60 . The lock nut  141  is slid upward on the tube  60 , engaging the underside of the snap ring  136 . The circumferential margin of the snap ring  136  bears on the chamfered entry aperture  152 . As the lock nut  141  continues its upward travel, the snap ring  136  is radially compressed by the chamfered entry aperture  142 . The standoff  154  has a height dimension that is great enough to force the snap ring  136  above the chamfered entry aperture  152 . When the radially compressed snap to ring  136  clears the chamfered entry aperture  152 , a snap ring  136  expands into the groove  138 . The standoff  134  of the lock nut  141  in combination with the chamfered entry aperture  152  greatly simplifies the process of positioning the snap ring  136  within the groove  138 . 
     A further preferred embodiment of the actuating fluid delivery system  10  is presented in FIG.  8 . The embodiment of FIG. 8 is what may be termed a claw lock connector. The lower collar  62  of the connector assembly  14  and the receiver assembly  15  each have features not found in the previously described embodiments. With respect to the lower collar  62 , a snap ring  156  is disposed in a groove  158  defined in the inner margin  159  of the lower collar  62 . The snap ring  156  holds a lower ferrule  152  in compressive engagement with an O-ring  160  and with the exterior margin of the lower spherical end  98  to effect a fluid tight seal between the lower collar  62  and the lower spherical end  98 . The lower portion of the lower collar  62 , as depicted in FIG. 8, defines a claw lock connector  162 . The claw lock connector  162  has a relatively slender neck  164  that expands radially outwardly into the integrally-formed claw  166 . The neck  164  and the claw  166  are designed to mate with the receiver assembly  15 . 
     The receiver assembly  15  of the embodiment depicted in FIG. 8 has an upper portion configured to function as a claw receiver  172 . The claw receiver  172  has an entry aperture  174  that is generally concentric with the tube  60  and spaced apart therefrom. The entry aperture  174  is defined between an upwardly extending inner projection  175  and an upwardly extending outer projection  176 . The entry aperture  174  is sized to accommodate the neck  164  of the connector  162 . The entry aperture  174  expands into a claw groove  177  at the lower margin of the entry aperture  174 . The claw groove  177  has an expanded diameter as compared to the entry aperture  174  and is designed to accommodate the claw lock connector  162  of the lower collar  62 . 
     The claw  166  does not define a full circumferential circular shape, but is in effect two semicircular, helical threads. In assembly, lower collar  62  is slid over the inner projection  175 . The lower collar  62  is then rotated approximately ¼ of a turn through which the helical shaped claws  166  engage and substantially fill the two semicircular claw grooves  177 . This means of compressive rotational engagement of the semicircular claws  166  with the semicircular claw grooves  177  is better appreciated with reference to the embodiment of FIGS. 9-11. 
     Referring now to FIGS. 9-11, a further embodiment of the actuating fluid delivery system  10  is depicted. The figures depict the connector assembly  14  of the delivery system  10 . It is understood that the connector assembly  14  is intended to be utilized in conjunction with a rail assembly  12  substantially as described with reference to FIG.  5 . The receiver assembly  15  includes a claw lock connector extending downwardly therefrom that has certain features that are similar to the claw lock connector described in conjunction with FIG.  8 . Instead of the snap ring  156  of FIG. 8, the embodiment of FIGS. 9-11 utilizes a lock nut  62  in threaded engagement with the receiver  15 . The lock nut  62  bears down on a lower ferrule  142  (see FIG. 10) to force the lower ferrule  142  into a compressive sealing engagement with the lower spherical end  98  (see FIGS.  10  and  11 ). Tightening of the lock nut  62  onto the connector  164  causes rotation of the connector  164  as indicated by arrow A in FIG. 9 a . Such rotation causes the helical claws  166  to engage the claw grooves  177  defined in the claw receiver  172 . 
     As depicted in FIGS. 9 a ,  10 , and  11 , each of the pair of claws  166  may be a portion of a helix, having an entry end  186  that has a lesser radius than the trailing end  188 . The entry end  186  has a slightly lesser radius than the radius of the claw groove  177  while the trailing end  188  has a slightly greater radius than the claw groove  177 . Accordingly, continued clockwise rotation after the entry end  186  of the claw  166  enters the claw groove  177  acts to seat the claw  166  ever more tightly in the claw groove  177 . 
     The rotation of the connector  164  caused by the rotative action of the lock nut  62  will continue until helical shaped claws  166  are wedged tightly within the claw groove  177 . At this point, rotation of the connector  164  ceases and continued rotation of the lock nut  62  acts to further compress the lower ferrule  142 . To disengage the lower collar  62  from the receiver assembly  15 , opposite rotation to that of arrow A is imparted to the lock nut  62 . Such rotation acts to withdraw the claws  166  from the respective claw grooves  177 . Rotation of the lower connector  164  is arrested when the claw stop  180  of the respective claws  166  comes into contact with the stop base  182  of the receiver assembly  15 . Continued counterclockwise rotation of the lock nut  62  acts to disengage the lock nut  62  from the lower connector  164 . 
     The present invention may be embodied in other specific forms without departing from the spirit of the essential attributes of the invention. Therefore, the illustrated embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.