Abstract:
An apparatus that injects fluid into an inflatable device, dynamically monitors the pressure inside the device, and automatically terminates the inflation and disconnects from the inflatable device when the pressure inside the device reaches a predetermined value preset by the operator. After securing a chuck to the valve of an inflatable device by simply pulling a trigger similar to that of a pistol, the operator initiates the inflation and does not need to intervene further.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Present Invention 
   The present invention relates to the fields of inflation systems and safety devices. 
   2. Status of the Related Art 
   Current art does not contain all the features claimed by the present invention. U.S. Pat. No. 5,365,967 (Moore, 1994) discloses a specially built tire valve with a built-in pressure indicator that emits a whistling sound when a preset pressure is attained. No adjustment feature on the preset pressure level is disclosed or claimed. U.S. Pat. No. 5,257,642 (Worth, 1993) discloses a pressure relief valve that can be inserted into a tire valve specially built with an integral on-off feature. The relief valve is preset to discharge air to the environment when a tire is inflated to a pressure greater than a predetermined value. The Moore and Worth inventions require valves that differ greatly from the industry standard and add undesirable wheel rim mass that can cause wheel balancing problems. Neither invention offers the safety benefit of hands-free, automatic disconnect of the inflation system at a desired pressure. 
   U.S. Pat. No. 5,857,481 (Zimmerman, 1999) discloses a tire inflation system that permits an operator to open a valve and inflate a remotely located tire through a flexible hose. The operator can set a desired tire pressure level on a pressure regulator located near the valve, and the hose can be disconnected from the regulator when the desired pressure is attained. U.S. Pat. No. 6,279,599 (Chen, 2001) discloses an air hose assembly that permits conventional inflation, and also provides for air release with a sliding mechanism, concentric with the hose assembly, with which the operator can hold the valve open until the desired amount of air is released. Neither invention offers the safety benefit of hands-free, automatic disconnect of the inflation system at a desired pressure. 
   U.S. Pat. No. 4,076,037 (Perez, 1978) discloses a safety valve that threads onto a conventional tire valve stem and relieves pressure above a preset value. It offers no inflation capability. 
   SUMMARY OF THE INVENTION 
   Injection of a fluid into an inflatable device is herein referred to as an “inflation event.” The component of an inflatable device that permits fluid ingress is herein called a “valve,” and the central core valve component that must be depressed to initiate fluid flow into the valve is herein called a “valve stem.” The component of an inflation device that interfaces directly with an inflatable device&#39;s valve is herein called a “chuck.” As herein used, “piston” refers to a component that slides inside a confined space such as a cylinder, and to a diaphragm-like or hinge-like component capable of moving from one position to another at the urging of gas pressure or a spring. As herein used, “spring” means any device or material capable of storing kinetic energy and returning at least a portion of that stored energy as kinetic energy. When used herein, “chamber” means an enclosed space that may or may not have one or more openings that provide communication with other enclosed spaces or with the atmosphere. 
   The present invention chuck provides easy, quick, and secure communication between an inflation device and an inflatable device. The present invention alleviates the major inconveniences and safety weaknesses inherent in inflation events carried out with state of the art inflation devices. After positioning the chuck on the valve of an inflatable device and pulling a trigger, the present invention requires no further operator interaction with the chuck. 
   For safety, the operator may initiate an inflation event entirely outside a protective cage that houses an inflatable device. For example, the remote feature enhances the safety of an inflation event such as the inflation of a truck tire with compressed air. The operator does not even have to put a hand inside the cage to hold the chuck onto a valve during the inflation process. 
   Fluid injected by the present invention is not limited to compressed air. The supply fluid reservoir can be any container or line system providing storage of a fluid, including, but not limited to a liquid, a gas, shop air, bottled gas, and a tank filled by a compressor. The reservoir can also be a direct connection to a compressor or pump. 
   With the present invention, a predetermined pressure inside an inflatable device causes the chuck to be automatically disconnected and released from the valve of the inflatable device. Such automatic disconnect without operator intervention at the valve assures a safe, handsfree conclusion of the inflation process. Disconnect at a predetermined pressure also assures a consistent inflation process when several devices are to be inflated to identical pressures. The safety and consistency of the present invention are valuable, desirable features in an assembly line environment such as, for example, a bicycle, motorcycle, automobile, truck, or tractor production, maintenance, or repair facility. 
   The present invention provides a means for setting the pressure at which the chuck will be automatically disconnected from the valve. This can be done by someone during the manufacturing, distribution, or retail stage, or by the operator. The setting can be permanent or variable. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The structure and operation of the invention will become apparent upon reading the following detailed description of the preferred embodiment and upon reference to the accompanying drawings in which like details are labeled with like identification numbers throughout, and in which: 
       FIG. 1  is an exploded view of the handle assembly, so-called because it is the portion of the preferred embodiment that is generally held by the operator during an inflation event. 
       FIG. 2A  is a cross-sectional side view of one half of the handle shell. 
       FIG. 2B  is a cross-sectional side view of the half of the handle shell opposite that of the half shown in  FIG. 2A . 
       FIG. 3  is an exploded view of the barrel assembly that mates with the handle assembly. 
       FIG. 4A  is a rear plan view of the trigger, a component of the barrel assembly. 
       FIG. 4B  is a side plan view of the trigger. 
       FIG. 5A  is a top plan view of the barrel, a component of the barrel assembly. 
       FIG. 5B  is a side plan view of the barrel. 
       FIG. 5C  is a bottom plan view of the barrel. 
       FIG. 6  is a plan view of the metering tube, a component of the barrel assembly. 
       FIG. 7  is a bottom plan view of the handle shell that shows, among other features, the viewing directions of  FIGS. 2A and 2B . 
       FIG. 8  is a plan view of the release piston, a component of the handle assembly. 
       FIG. 9A  is a plan side view of the present invention. 
       FIG. 9B  is a cross-sectional side view of the present invention. 
       FIG. 9C  is a partial cross-sectional cut-away drawing of the chuck portion of the present invention and the valve of an inflatable device. 
       FIG. 9D  is a partial cross-sectional cut-away drawing of the chuck portion of the present invention grasping the valve of an inflatable device. 
       FIG. 10  is an exploded view of an alternative embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Inventor presents herein the best mode for carrying out the present invention in terms of its preferred embodiment, depicted within the aforementioned drawings. 
     FIG. 1  is an exploded view of handle assembly  1 . From a reservoir or other source not shown, pressurized fluid is introduced into an interchangeable fluid supply connector  40  connected to handle shell  99 . 
     FIG. 2A  is a cross-sectional view of handle shell  99 . Connector  40  is threaded into threaded hole  2  of handle shell  99 . The pressurized fluid that flows through connector  40  flows into the section of filter  41  (see  FIG. 1 ) that occupies chamber  3  of handle shell  99 , through the section of filter  41  that is threaded into threaded hole  4 , and through chambers  5 ,  6 , and  7 . Groove  8  houses O-ring  42 , discussed below as part of handle assembly  1 . 
     FIG. 3  is an exploded view of barrel assembly  69 . O-rings  156 ,  159 , and  166  are respectively installed in metering tube grooves  155 ,  158 , and  165 . Compliant washer  200 , rigid spacer  190 , and valve stem actuator  185  are installed inside lower chuck body  210 . Middle chuck body  180  is inserted into lower chuck body  210 , and metering tube  150  is inserted into middle chuck body  180  so that diametrical pin hole  181  in middle chuck body  180 , diametrical pin hole  211  in lower chuck body  210  and diametrical pin hole  223  in metering tube  150  are aligned. Metering tube  150  and middle and lower chuck bodies  180  and  210  are pinned together with cylindrical pin  222  pressed through the three mating pin holes. 
   Heretofore, for purpose of description, the open end of barrel  120  will be referred to as the front end of barrel  120  and barrel assembly  69 , and the direction in which the front end of barrel  120  and barrel assembly  69  face will be referred to as “forward.” Any component orientation or motion coincident with that direction will be considered to the front or “forward.” Any component orientation or motion opposite to that direction will be considered to the rear or “rearward.” 
   Referring again to  FIG. 3 , compression spring  153 , with an inside diameter smaller than the outside diameter of metering tube  150  and an outside diameter smaller than the inside diameter of barrel central chamber  122 , is installed inside barrel central chamber  122 . Internally tapered upper chuck body  230  is pressed into the front end of barrel  120  so that the largest diameter of the chuck body  230  taper faces forward. 
   In the preferred embodiment, chuck holes  218  are cut with a ball end mill circumferentially on equally spaced radii and near the forward end of lower chuck body  210 . The resulting configuration of a chuck hole  218  is a curved hole on the outer surface of lower chuck body  210  that tapers inward to a curved hole on the inside surface of lower chuck body  210 , the outer hole having a larger diameter than the inner hole. Chuck balls  217  are sized so that they cannot pass entirely through chuck holes  218 . When seated in a chuck hole  218 , some portion of a chuck ball  217  protrudes inside the inner surface of lower chuck body  210 , and some other portion of a chuck ball  217  protrudes outside the outer surface of lower chuck body  210 . Chuck balls  217  are seated in chuck holes  218 , and the end of metering tube  150  in which O-ring  156  is seated is inserted through upper chuck body  230  and into barrel chamber  122 . Lower chuck body  210  is inserted into upper chuck body  230  far enough to assure that chuck balls  217  are captured between chuck holes  218  and the tapered inside diameter of upper chuck body  230 . 
     FIGS. 4A and 4B  show trigger  240  and its hemispherical slot  247  that is inserted into barrel slot  126 , shown in  FIG. 5C . Hemispherical trigger slot  247  receives metering tube  150 , and trigger  240  is attached to metering tube  150  with screws  245  and  246  that communicate through trigger holes  241  and  243 , respectively, with metering tube threaded holes  168  and  169 , respectively, when metering tube  150  is inserted into barrel central chamber  122  (see  FIG. 3 ). Thus attached to trigger  240 , metering tube  150  is captured within, and is capable of sliding inside, barrel central chamber  122  when an operator slides trigger  240  in barrel slot  126 . 
   In  FIG. 1  it can be seen that release piston  83  and its seated O-ring  87  are concentrically installed on release pin  78  and held in place between spring clips  82  and  89  that are seated in grooves  81  and  88 , respectively. Release pin  78  mounts through hole  91  in release pin guide  90  that is seated in handle chamber  16  (see  FIG. 2A ), and communicates with barrel hole  123  (see  FIG. 5C ). Handle assembly  1  is inserted into cutout  127  of barrel  120  (see  FIG. 5B ) and is attached to barrel  120  with four screws  139  (see  FIG. 3 ) that communicate with threaded holes  24  in handle shell  99  through barrel counterbored clearance holes  128 . 
   Heretofore, for purposes of description of the combined handle and barrel assemblies  1  and  69 , the end of handle assembly  1  that receives fluid supply connector  40  will be referred to as the “bottom end,” and the opposite end (the end joined with barrel  120 ) will be referred to as the “top end.” Motion in the direction toward the top and bottom ends will be referred to as “upward” and “downward,” respectively. 
   No Fluid Flow through Barrel Assembly: Absent external force on trigger  240 , compression spring  153  seated against the rear wall of barrel central chamber  122  exerts a longitudinal force against the rear end of metering tube  150 . That force pushes metering tube  150  and attached trigger  240  forward until the front end of trigger  240  impinges the front end of barrel slot  126 . The barrel assembly parts are dimensioned so that when trigger  240  is held in the foregoing forward position by spring  153 , chuck balls  217  seated in chuck holes  218 , are captured by lower chuck body  210  and upper chuck body  230 . 
   With metering tube  150  in its forward position, O-rings  156  and  159  approximately span barrel holes  125  so that fluid at reservoir pressure in handle chamber  7  is laterally confined by O-ring  42  in groove  8 , and communicates through holes  125  to confinement in the annular chamber defined by the outer surface of metering tube section  157 , the inner surface of barrel central chamber  122 , and O-ring  156  in groove  155  and O-ring  159  in groove  158  (see  FIG. 6 ). 
     FIG. 7  shows that handle angled chamber  28  joins handle chamber  5  and handle chamber  19  (sealed during assembly by means of O-ring  105 , port cover  101 , and screw  100 ).  FIG. 7  also shows that handle angled chamber  29  joins handle chambers  19  and  10 . Regulator  57 , discussed in detail below and shown in  FIG. 8 , is located near or at its uppermost or topmost position in handle chamber  10  so that fluid from angled chamber  29  is confined in the annular chamber defined by the outer surface of section  59  of regulator piston  57 , the inner surface of handle chamber  10 , and O-ring  56  seated in groove  58  and O-ring  61  seated in groove  60 . 
   Thus, with metering tube  150  in its forward position, fluid flow is blocked, and fluid pressure in the annular chamber between the outer surface of metering tube section  157 , the inner surface of barrel central chamber  122 , and O-rings  156  and  159  stabilizes at the fluid reservoir pressure. Consequently, when trigger  240  and metering tube  150  are spring loaded in their forward positions, there is no fluid flow through the forward end of metering tube  150  and lower chuck body  210 . 
   Fluid Flow through Barrel Assembly into the Atmosphere: An operator initiates fluid flow through lower chuck  210  by pulling trigger  240  rearward. When rearward motion of trigger  240  is sufficient to cause metering tube cavity  167  to line up with barrel hole  123 , chamfered tip  98  of release pin  78  in handle chamber  16  seats in metering tube cavity  167 . Release pin  78  is guided by release pin guide  90  seated in handle chamber  16  and sealed with O-ring  94  seated in release pin guide groove  93 . Release pin  78  is urged into metering tube cavity  167  by compression spring  77  and spacer  76 , concentric to release pin  78  in handle chamber  16 , that exerts a force that is parallel to release pin  78  and that is imposed on release piston  83  concentrically attached to release pin  78  between release pin grooves  81  and  88 . With chamfered tip  98  of release pin  78  seated in metering tube cavity  167 , metering tube  150  is locked in its most rearward position, and further movement of trigger  240  and metering tube  150  is precluded. 
   With metering tube  150  in its rearward position, the annular chamber defined by the outer surface of metering tube section  162 , the inner surface of barrel central chamber  122 , and O-ring  159  seated in groove  158  and O-ring  166  seated in groove  165  approximately spans barrel holes  124  and  125 . In this configuration, fluid confined by O-ring  42  seated in groove  8  flows through handle chamber  7 , through barrel holes  125 , and into the annular chamber between the outer surface of metering tube section  162 , the inner surface of barrel central chamber  122 , and O-rings  159  and  166 . From that annular chamber the fluid flows through metering tube holes  161  and  164  into metering tube center bore  152 . If lower chuck body  210  is not properly attached to an inflatable device, the fluid will escape into the atmosphere through the forward end of metering tube  150  and lower chuck body  210 . 
   To stop the escape of fluid, an operator may pull release knob  70  downward (away from the bottom end of handle shell  99 ). Knob  70  is attached to release pin  78  with set screws  75  that impinge on release pin groove  80 . Piston  83  is concentrically secured to release pin  78  between release pin grooves  81  and  88 . Pulling knob  70  downward with sufficient force to overcome the force of compression spring  77  seated against piston  83  pulls chamfered tip  98  of release pin  78  out of metering tube cavity  167 . Compressed spring  153  then pushes metering tube  150  and attached trigger  240  into their forward positions, thus blocking barrel holes  125  and stopping the flow of fluid through barrel holes  125  and the forward end of metering tube  150  and lower chuck body  210 . Consequently, with trigger  240  and metering tube  150  spring loaded in their forward positions, there is no fluid flow through the forward end of metering tube  150  and lower chuck body  210 . 
   Fluid Flow through Barrel Assembly into an Inflatable Device: Communication between a fluid reservoir and an inflatable device requires proper attachment of a chuck to the inflatable device&#39;s valve. For practice of the present invention, the operator pushes upper chuck body  230  and lower chuck body  210  (see  FIGS. 9C and 9D ) onto the valve  300  of an inflatable device so that rubber washer  200  contacts the valve, and valve stem actuator  185  depresses the valve stem  310  sufficiently to permit fluid flow into the inflatable device. Chuck balls  217  contact the outer surface of the valve. Applying forward force to handle and barrel assemblies  1  and  69  sufficient to assure that valve stem actuator  185  keeps the valve stem of the inflatable device depressed, the operator pulls trigger  240  rearward. Because metering tube  150  is pinned to middle and lower chuck bodies  180  and  210 , and lower chuck body  210  receives the valve of an inflatable device, pulling trigger  240  rearward results in forward movement of handle and barrel assemblies  1  and  69 , respectively. Consequently, because upper chuck body  230  is part of barrel assembly  69 , the tapered inside surface of upper chuck body  230  moves forward onto lower chuck body  210 , forcing chuck balls  217  deeper in chuck holes  218 . Thus the portions of chuck balls  217  protruding inside the inner diameter of lower chuck body  210  impose a circumferential radial force on the captured valve of the inflatable device. As the narrowing section of the tapered inside surface of upper chuck body  230  is forced further forward, chuck balls  217  grip the valve with greater force. 
   When rearward motion of trigger  240  is sufficient to cause metering tube cavity  167  to line up with barrel hole  123 , chamfered tip  98  of release pin  78  in handle chamber  16  seats in metering tube cavity  167 . Release pin  78  is urged into metering tube cavity  167  by compression spring  77  as described above. With chamfered tip  98  of release pin  78  seated in metering tube cavity  167 , metering tube  150  is locked in its most rearward position, and further movement of trigger  240  and metering tube  150  is precluded. 
   With metering tube  150  in its rearward position, the annular chamber defined by the outer surface of metering tube section  162 , the inner surface of barrel central chamber  122 , and O-ring  159  seated in groove  158  and O-ring  166  seated in groove  165  is approximately centered over barrel holes  124  and  125 . In this configuration, fluid confined by O-ring  42  seated in groove  8  flows freely through handle chamber  7 , through barrel holes  124  and  125 , and into the annular chamber between the outer surface of metering tube section  162 , the inner surface of barrel central chamber  122 , and O-rings  159  and  166 . From that annular chamber the fluid flows through metering tube holes  161  and  164 , into metering tube center bore  152 , through lower chuck body  210 , and into the inflatable device valve. 
   The operator can stop the inflation process at any time by manually pulling release knob  70  downward (away from handle shell  99 ). Additionally, the present invention provides for termination of the inflation process with automatic disconnect of lower chuck body  210  from the valve of the inflatable device and automatic cessation of fluid flow from the barrel assembly at a predetermined inflation pressure. 
   Automatic Chuck Disconnect: Before the inflation process begins, the operator selects and sets a pressure at which the inflation process will be terminated.  FIG. 1  shows that the operator adjusts the present invention to achieve a desired pressure in the inflatable device by rotating pressure adjuster  50  clockwise to compress spring  55  and counter-clockwise to relieve spring  55 . The function that spring  55  performs in the regulation of the pressure in the inflatable device is discussed below. The desired pressure is indicated by the position, relative to handle marker  250 , of visible scale  251  on pressure adjuster  50 . 
   Handle assembly  1  contains a mass flow rate restrictor.  FIGS. 2A and 2B  show that handle chamber  6  has a cross-sectional area significantly smaller than any of the other fluid flow chambers in the present invention. The ganged chamber comprised of barrel holes  125  and the ganged chamber comprised of metering tube holes  161  and  164  each constitute a chamber with a combined cross-sectional area significantly larger than that of handle chamber  6  and the inflatable device valve. For example, in the preferred embodiment, handle chamber  6  and each barrel hole  125  has a diameter of 0.031 in. Therefore, the combined cross-sectional area available for fluid flow in the four barrel holes  125  of the preferred embodiment is four times that of the cross-sectional area available for fluid flow in handle chamber  6 . In the preferred embodiment, metering tube holes  161  and  164  have a diameter of 0.046 in. Therefore, the combined cross-sectional area available for fluid flow in metering tube holes  161  and  164  of the preferred embodiment is 4.4 times that of the cross-sectional area available for fluid flow in handle chamber  6 , and the cross-sectional area in the inflatable device valve is approximately three times that of the cross-sectional area available for fluid flow in the handle chamber  6 . 
   Therefore, handle assembly  1  contains a mass flow rate restrictor. When the inflation process begins, fluid pressure inside all chambers downstream of handle chamber  6  stabilizes at the same pressure present in the inflatable device, while fluid pressure in handle chambers  2  through  6  is equal to the pressure of the fluid reservoir. Because of friction and the flow restriction imposed by handle chamber  6 , communication between a fluid reservoir and an inflatable device through handle assembly  1  and barrel assembly  69  does not instantaneously raise the inflatable device pressure to that of the reservoir. Rather, the pressure of the fluid in the chambers downstream of handle chamber  6 , and in the inflatable device, gradually increases as fluid flows through the restricted handle chamber  6 . 
   During the inflation process, the fluid pressure in metering tube center bore  152 , metering tube holes  161  and  164 , barrel holes  124  and  125 , and handle chambers  10  and  11  rise at substantially the same rate as the pressure in the inflatable device. The increasing fluid pressure in handle chambers  10  and  11  gradually increases the force exerted by the fluid on the top surface of regulator piston  57  that is fitted inside handle chamber  10  with O-rings  56  and  61  seated in regulator piston grooves  58  and  60 , respectively (see  FIG. 8 ). Where handle assembly  1  joins barrel assembly  69 , fluid in handle chamber  11  is confined by O-ring  63  seated in groove  12 . The increasing force pushes piston  57  downward, compressing spring  55 . As regulator piston  57  moves downward, it approaches an opening created where angled chamber  30  intersects with handle chamber  10  (see  FIG. 2B ). That opening in the wall of handle chamber  10  permits communication, through angled chamber  30 , between handle chambers  10  and  22 . Angled chamber  30  normally vents to the atmosphere through handle chamber  22  (sealed during assembly by means of O-ring  105 , port cover  101 , and screw  100 ) and angled chamber  31  that in turn communicates with the atmosphere through handle chambers  16 ,  15 ,  14 , and  13 . 
   As regulator piston  57  moves further downward in handle chamber  10 , O-Ring  56  passes over the opening to angled chamber  30 . At that point the annular chamber defined by the outer surface of section  59  of regulator piston  57 , the inner surface of handle chamber  10 , and O-rings  56  and  61  is brought into communication with angled chamber  30 . That annular chamber maintains pressure equal to that of the fluid reservoir, such pressure being communicated from the reservoir through handle chamber  5 , angled chamber  28 , handle chamber  19  (sealed during assembly by means of O-ring  105 , port cover  101 , and screw  100 ), and angled chamber  29  that intersects handle chamber  10  at a location upward from the point of intersection of angled chamber  30  (see  FIGS. 2A and 2B ). When the annular chamber defined by the outer surface of section  59  of regulator piston  57 , the inner surface of handle chamber  10 , and O-rings  56  and  61  simultaneously spans the intersections of angled chambers  29  and  30  with handle chamber  10 , the pressure of the fluid in angled chamber  30  will immediately change from atmospheric to that of the fluid reservoir. 
   When the pressure change in angled chamber  30  occurs is dependent on the mechanical properties and initial length of spring  55 . When the inflation process begins, the initial length of spring  55  is determined by the position of pressure adjuster  50  and its shank  48  in threaded handle chamber  9 . Thus the present invention enables an operator to adjust, with pressure adjuster  50  aided by marker  250  and a visible scale  251  on pressure adjuster  50 , the initial compressive force in spring  55 , thereby setting the inflation pressure that initiates the series of actions that overcomes the force in spring  55  and automatically disconnects lower chuck body  210  from the inflatable device valve. 
   When angled chamber  30  achieves reservoir pressure, handle chamber  22 , angled chamber  31 , and handle chamber  16  substantially simultaneously achieve reservoir pressure. Where handle assembly  1  joins barrel assembly  69 , fluid in handle chamber  16  is confined by O-ring  94  seated in groove  17 . Fluid at reservoir pressure in handle chamber  16  exerts a force on the top surface of release piston  83 . Because the bottom surface of release piston  83  is exposed to atmospheric pressure in handle chambers  13 ,  14 , and  15  and around release knob  70 , and because O-ring  87  seated in release piston groove  86  seals the periphery of release piston  83  in handle chamber  16 , the increasing pressure on the top surface of release piston  83  pushes the piston downward. 
   As release piston  83  moves downward, attached release pin  78  moves with it, thereby disengaging chamfered tip  98  of release pin  78  from metering tube cavity  167 . Spring  153 , seated in the rear of barrel central chamber  122 , then thrusts the barrel and handle assemblies  69  and  1  rearward, away from metering tube  150 . Thus the effect of spring  153  is to push barrel  120  and upper chuck body  230  away from pinned middle and lower chuck bodies  180  and  210  and metering tube  150 . As upper chuck body  230 , with its internal taper, is pushed away from lower chuck body  210 , the force exerted on chuck balls  217  by upper chuck body  230  decreases, thereby reducing the radial forces exerted by chuck balls  217  on the inflatable device valve. At some reduced level of force exerted by chuck balls  217  on the inflatable device valve, the spring-loaded valve stem pushing against valve stem actuator  185  will eject lower chuck body  210 , metering tube  150 , and barrel and handle assemblies  69  and  1 , and the inflation process will terminate. 
   When the present invention inflation device has been ejected from the inflatable device valve, spring  153  maintains metering tube  150  in its forward position, and the annular chamber defined by the outer surface of metering tube section  162 , the inner surface of barrel central chamber  122 , and O-rings  159  and  166  no longer straddles barrel holes  124  and  125 . Rather, O-rings  156  and  159  approximately span barrel holes  125  so that fluid in handle chamber  7  communicates through holes  125  with the annular chamber defined by the outer surface of metering tube section  157 , the inner surface of barrel central chamber  122 , and O-rings  156  and  159 . Where handle assembly  1  joins barrel assembly  69 , fluid in handle chamber  7  is confined by O-ring  42  seated in groove  8 . Thus, when the inflation process has been terminated, and metering tube  150  is in its forward position, fluid flow at reservoir pressure through holes  125  is confined to the annular chamber defined by the outer surface of metering tube section  157 , the inner surface of barrel central chamber  122 , and O-rings  156  and  159 . And fluid flow at reservoir pressure from handle chamber  5  is confined to angled chamber  28 , handle chamber  19  (sealed during assembly by means of O-ring  105 , port cover  101 , and screw  100 ), angled chamber  29 , and the annular chamber between regulator piston  57 , handle chamber  10 , and O-rings  56  and  61  stabilizes at the fluid reservoir pressure. Consequently, there is no fluid flow through metering tube  150  or lower chuck body  210 . 
   With atmospheric pressure on both ends of regulator piston  57 , spring  55  extends to its initial length, and regulator piston  57  returns to its neutral position, blocking angled chamber  30  from fluid at reservoir pressure. The top surface of release piston  83  is therefore no longer exposed to reservoir pressure, and spring  77  pushes release pin  78  to its neutral position with chamfered tip  98  of release pin  78  held against metering tube  150  between metering tube cavity  167  and O-ring  166 . Thus, after an inflation process has terminated, the components of the present invention return to a configuration and state ready for another inflation event. 
   Because handle chamber  6  has a cross-sectional area significantly smaller than any of the other fluid flow chambers in the present invention, handle chamber  6  restricts the fluid flow rate into all the chambers in the fluid flow path between handle chamber  6  and the inflatable device, and between handle chamber  6  and handle chamber  10  where pressure regulation occurs. Variations of the preferred embodiment can be achieved by designing the fluid flow rate restriction in any section of the fluid flow path that assures that the pressure build-up in handle chamber  10  is sufficiently controlled such that the pressure against the top surface of regulator piston  57  does not instantaneously reach reservoir pressure and consequently instantaneously initiate the automatic chuck disconnect process. One such variation could be achieved by eliminating the restriction of handle chamber  6 , eliminating three of the holes  125 , and then relying on the restriction created by the single remaining small diameter hole  125 . 
   Premature initiation of the automatic chuck disconnect process can also be avoided with different ratios between the cross-sectional area of the chambers downstream of the flow restricting chamber and the flow restricting chamber itself. Although the preferred embodiment discloses a ratio between the smallest chamber downstream of the restricting handle chamber  6  (the annular area around the valve stem for the preferred embodiment) and chamber  6  of approximately three-to-one, that ratio is not mandatory. Depending on parameters including but not limited to the density of the fluid, the overall friction in the fluid flow path, including the effects of sharp turns or radiused bends, and spring rates of any springs or other components influenced by fluid pressure in a way to affect an automatic chuck disconnect or automatic fluid flow cessation, the ratio could theoretically be smaller than that of the preferred embodiment. 
   Reference to  FIG. 3  should suggest to one versed in the mechanical arts another variation on the preferred embodiment. With provision of the functionality of compliant washer  200 , rigid spacer  190 , and valve stem actuator  185 , middle chuck body  180  could be incorporated into lower chuck body  210  or metering tube  150 , thereby eliminating one machined or extruded tube and simplifying the assembly process. 
   In the present invention, pressure adjuster  50  is a knurled knob on one end of a threaded shaft. Alternatively, the adjuster could be a lever, slider, cam, dial, wheel, or equivalent device. 
   An option that could be made available for the preferred embodiment is a means of fixing the preset automatic disconnect pressure, thereby precluding its change by unauthorized operators. Such a feature could be realized with a locking mechanism, such as a pin, weldment, or epoxy applied to pressure adjuster  50 . For a fixed disconnect pressure, pressure adjuster  50  could also be designed as a fixed stop for spring  55 , thus allowing no adjustment whatsoever. With a fixed stop, the present invention could be offered with a set of springs  55 , each with a different spring rate (sometimes called spring constant) that would result in a set of discrete, non-adjustable, preset disconnect pressures. 
     FIG. 10  illustrates another present invention embodiment variation in which handle assembly  1  and barrel assembly  69  are separated by a flexible tube or hose. Such an embodiment permits an operator to inflate an inflatable device that might be too small to conveniently accommodate the length of barrel assembly  69  in close proximity to the valve of the inflatable device. 
     FIG. 10  illustrates how the present invention functions of grasping the valve of an inflatable device and, at a predetermined inflatable device pressure, automatically disconnecting from the valve, can be performed remotely from barrel  120 . The forward end of metering tube  150  is threaded to form opening  152 A and fitted with a first tube connector  260 . The first end of flexible tube  265  is mounted on the forward end of tube connector  260 . The first end of sheath  270 , concentrically installed on tube  265 , is pushed against the forward face of flange  280  on tube connector  260 . Sheath  270  and flexible tube  265  are sized so that the latter is slideable inside the former. 
   The second end of sheath  270  is concentrically and firmly attached to the first end of remote chuck body  231 . Such attachment may be press fit, adhesive, or other equivalent means. The second end of flexible tube  265 , running inside sheath  270 , extends through the first end of remote chuck body  231 , the second end of remote chuck body  231 , and compression spring  255 , and is installed on a second tube connector  260 . 
   Compliant washer  200 , rigid spacer  190 , and valve stem actuator  185  are installed inside lower chuck body  210 . Middle chuck body  180  is inserted into lower chuck body  210  so that diametrical pin hole  181  in middle chuck body  180 , diametrical pin hole  211  in lower chuck body  210 , and a diametrical pin hole (not shown) in second tube connector  260  are aligned. Middle and lower chuck bodies  180  and  210 , and second tube connector  260  are pinned together in the same manner as middle and lower chuck bodies  180  and  210  and metering tube  150  in barrel assembly  69  illustrated in  FIG. 3 . The pinning process must not block fluid flow through any of the pinned components. As an alternative to pinning, second tube connector  260  may be threaded into a middle chuck body  180  modified with internal threads, or made integral to a middle chuck body  180 . When the pinned or otherwise attached components are assembled, middle chuck body  180  is partially inside lower chuck body  210 , which, along with spring  255 , is partially inside remote chuck body  231 . 
   From  FIG. 10  it can be seen that flexible tube  265  acts as an extension of metering tube  150 , and functions as a link in the transfer of force from trigger  240  to remote chuck body  210  while also acting as part of the path for fluid flow from metering tube center bore  152  to the inflatable device. As with the preferred embodiment, the operator of the present invention in its  FIG. 10  alternative embodiment pushes remote chuck body  231  and lower chuck body  210  onto the valve of an inflatable device (not shown) so that rubber washer  200  contacts the valve, and valve stem actuator  185  depresses the valve stem sufficiently to permit fluid flow into the inflatable device. Chuck balls  217  contact the outer surface of the valve. 
   Applying force to remote chuck body  231  and lower chuck body  210  sufficient to assure that valve stem actuator  185  keeps the valve stem of the inflatable device depressed, the operator pulls trigger  240  rearward. Because metering tube  150  is attached to flexible tube  265 , which is in turn attached to middle and lower chuck bodies  180  and  210 , because sheath  270  is selected to resist compression, and because lower chuck body  210  receives the valve of an inflatable device, pulling trigger  240  rearward results in forward movement of the handle and barrel assemblies, and movement of sheath  270  toward the valve. That movement of sheath  270  moves remote chuck body  231  toward the valve, partially compressing spring  255 . Consequently, the tapered inside surface of remote chuck body  231  is pushed further onto lower chuck body  210 , forcing chuck balls  217  deeper in chuck holes  218 . Thus the portions of chuck balls  217  protruding inside the inner diameter of lower chuck body  210  impose a circumferential radial force on the captured valve of the inflatable device. As the narrowing section of the tapered inside surface of remote chuck body  231  is forced further onto lower chuck body  210 , chuck balls  217  grip the valve with greater force. 
   Fluid flowing from metering tube  150  passes through flexible tube  265  into the valve. When the pressure in the inflatable device reaches the predetermined desired value, lower chuck body  210  is automatically disconnected from the valve in the same manner, with one exception, as it is disconnected in the preferred embodiment. In the  FIG. 10  alternative embodiment, the automatic disconnect feature is assisted by the conserved energy in spring  255  that was compressed in the process of attaching lower chuck body  210  to the valve of the inflatable device. The additional force of disconnect is needed to overcome the friction between flexible tube  265  and sheath  270  inherent in the  FIG. 10  alternative embodiment. 
   It will be apparent to those with ordinary skill in the relevant art having the benefit of this disclosure that the present invention provides an inflation device with an easily attachable hands-free chuck that is automatically detached from the valve of an inflatable device at a preset pressure. It is understood that the forms of the invention shown and described in the detailed description and the drawings are to be taken merely as presently preferred examples and that the invention is limited only by the language of the claims. The drawings and detailed description presented herein are not intended to limit the invention to the particular embodiments disclosed. While the present invention has been described in terms of one preferred embodiment and a few variations thereof, it will be apparent to those skilled in the art that form and detail modifications can be made to those embodiments without departing from the spirit or scope of the invention.