Patent Publication Number: US-10315910-B2

Title: Nozzle for a liquid dispensing spout

Description:
BACKGROUND 
     Portable plastic fuel containers are well known. Most are equipped with a spout by which fuel in the container can be controllably dispensed. 
     While such spouts appear to be simple devices, they should satisfy environmental rules and regulations as well as consumer product safety regulations. They are also preferably safe and reliable to use in order to avoid product liability claims and preferably inexpensive to manufacture. A liquid fuel dispenser satisfying such requirements would be an improvement over the prior art. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1A  depicts a liquid dispensing spout on a conventional, portable fuel canister; 
         FIG. 1B  is a front perspective view of a liquid dispensing spout; 
         FIG. 2  is a second, rear perspective view of the liquid dispensing spout; 
         FIG. 3  is an exploded view of the liquid dispensing spout; 
         FIG. 4  is a cross-sectional view of the liquid dispensing spout; 
         FIG. 5  is a front perspective view of a nozzle for the liquid dispensing spout; 
         FIG. 6  is a rear perspective view of the nozzle; 
         FIG. 7  is a cutaway view of the nozzle; 
         FIG. 8  is an end view of the nozzle, looking into the nozzle from the end that abuts the body of the liquid dispensing spout; 
         FIG. 9  is an isolated cross sectional view of the liquid dispensing spout showing linked poppet valves in greater detail; 
         FIG. 10  is an isometric view of the front side or face of the spout body; 
         FIG. 11  is a side view of the spout body; 
         FIG. 11  is a cross sectional view of the spout body; 
         FIG. 13  is a perspective view of the preferred embodiment of linked poppet valves; 
         FIG. 14A  is a side view of the preferred embodiment of linked poppet valves; 
         FIG. 14B  is also the side view of the preferred embodiment of linked poppet valves, marked to show offset spacing between O-rings on the poppet valves; 
         FIG. 15  is a perspective view of a linked poppet valve and its actuator; 
         FIG. 16  is a side view of a linked poppet valve and its actuator; 
         FIG. 17  is a top view of a linked poppet valve and its actuator; 
         FIG. 18  is a rear view of the spout body; 
         FIG. 19A  is a perspective view of a valve actuator block; 
         FIG. 19B  is a perspective view of the valve actuator block engaged with the clip on the distal end of the valve stem of the linked poppet valves and encircled by a coil spring; 
         FIG. 20  is a perspective view of an alternate embodiment of a valve actuator; 
         FIG. 21  is a rear perspective view of a child-resistant liquid dispensing spout actuator; 
         FIG. 22  is a front perspective view of the child-resistant liquid dispensing spout actuator; 
         FIG. 23  is a front perspective view of the child-resistant liquid dispensing spout actuator mounted on the spout body; 
         FIG. 24A  is a perspective view of a vent tube for the liquid dispensing spout; 
         FIG. 24B  is a cross sectional view of the vent tube; 
         FIG. 25A  shows the liquid dispensing spout attached to an upright, conventional portable fuel canister that contains fuel, the canister being shown in cross section; 
         FIG. 25B  shows the liquid dispensing spout attached to an inverted, conventional portable fuel canister that contains fuel, the canister being shown in cross section; 
         FIG. 26A  is a perspective view of an alternate embodiment of linked poppet valves with an alternate embodiment of a valve stem; 
         FIG. 26B  is a cross section of the alternate embodiment of a valve stem that is shown in  FIG. 26A ; 
         FIG. 27A  is a perspective view of an alternate embodiment of linked poppet valves with an alternate embodiment of a valve stem; 
         FIG. 27B  is a cross section of the alternate embodiment of a valve stem that is shown in  FIG. 26A ; 
         FIG. 28A  is a perspective view of an alternate embodiment of linked poppet valves with an alternate embodiment of a valve stem; 
         FIG. 28B  is a cross section of the alternate embodiment of a valve stem that is shown in  FIG. 26A ; 
         FIG. 29  shows an alternate embodiment of a linked poppet actuator; 
         FIG. 30  shows an alternate embodiment of linked poppet valves, the alternate embodiment shown having poppet O-rings that are substantially coplanar, i.e., they lie on, or in, the same geometric plane; 
         FIG. 31  shows an alternate embodiment of linked poppet valves; 
         FIGS. 32 and 33  shown another alternate embodiment of linked poppet valves; 
         FIG. 34  shows an alternate embodiment of a child-resistant actuator for a liquid dispensing spout; 
         FIG. 35  shows an alternate embodiment of a child-resistant actuator for a liquid dispensing spout; 
         FIG. 36  shows an alternate embodiment of a child-resistant actuator for a liquid dispensing spout; and 
         FIG. 37  shows an alternate embodiment of a vent tube for a liquid dispensing spout. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  depicts a liquid dispensing spout  100  attached to a conventional, portable gasoline can, i.e., a reservoir  101 . The reservoir  101  can be made of plastic or metal. 
       FIG. 1B  is a front perspective view of the liquid dispensing spout  100 .  FIG. 2  is a rear perspective view of the liquid dispensing spout  100 .  FIG. 3  is a cross sectional view of the liquid dispensing spout  100 . 
     As can be seen in  FIGS. 1-3 , the liquid dispensing spout  100  comprises a spout body  102 . A nozzle  200  is attached to a front side  103  of the spout body  102  by plastic tabs  104 , which are cantilevered from the front side  103 , at both the top and bottom of the spout body  102 . 
     The spout body  102  also “carries” or supports linked poppet valves  300 , visible in in  FIG. 3 , a linked poppet valve actuator  400 , also visible in  FIG. 3 , a child-resistant actuator  500 , and an air inlet tube  600 . 
     An internally-threaded mounting collar  120 , also attached to the spout body  102  “screws onto” a threaded inlet of the reservoir  101 . The mounting collar  120  provides a substantially air-tight seal between the liquid dispensing spout  100  and the reservoir  101 . 
     As described below and as shown in the figures, the liquid dispensing spout  100  allows a liquid to be controllably dispensed from the reservoir  101 , which is preferably sealed by the mounting collar  120  so that the reservoir  101  is essentially air tight. 
     As used herein, the term, “controllably dispensed” should be construed as dispensing liquid from the reservoir  101  with little or no pulsation of liquid flowing from nozzle  200 . Such pulsation is sometimes referred to as either “chugging,” “glugging” or burping. Regardless of the term used to describe the pulsation phenomenon it is caused by negative pressure that develops in an unvented or inadequately vented reservoir by the effluence of liquid, and a sudden in-rush of air to the reservoir through the conduit through which the liquid is supposed to flow. 
     “Controllably dispensed” also includes inhibiting the operation of the liquid dispensing spout by a young child. It also includes inhibiting the flow of liquid from the reservoir  101  when the open end  210  of the nozzle  200  becomes immersed or submerged in the liquid being dispensed. 
     With regard to being child resistant, the liquid dispensing spout  100  is configured as described below such that fluid can be dispensed after disabling a mechanical safety “switch” and then pushing the poppet valve actuator  400  toward the spout body  102 . 
     Fluid flow is inhibited after the open end of the nozzle  200  becomes submerged by cutting off the flow of air into the reservoir  101  via the nozzle  200  thereby creating a negative pressure in the reservoir  101 . Stated another way, vent air into the reservoir  101  is cut off when the reservoir  101  is rotated or tipped from an upright position and when the open end  210  of the nozzle is submerged. 
     As shown in  FIGS. 1A, 25A and 25B , the vent tube  600  extends downwardly from the mounting collar  120 . The vent tube  600  has a length such that its distal open end  602  is near the bottom of the reservoir  101 . When the reservoir  101  is upright as shown in  FIG. 25A , a relatively small volume of liquid will be pushed upwardly into the vent tube. When the reservoir  101  is rotated or tilted, as shown in  FIG. 25B , some liquid in the vent tube  600  may become trapped inside the tube  600 . 
     By opening a liquid control poppet before the air control poppet opens, a small volume of liquid from the reservoir  101  flows out of the reservoir  101  before air is allowed into the reservoir  101 . Allowing liquid to flow out of the reservoir  101  before air flows in, creates a small negative pressure in the reservoir, which evacuates liquid trapped in the vent tube  600  and allowing air to thereafter flow into the reservoir  101 . The sequential opening of the poppet valves  300  as described below is thus important to controllably dispensing liquid. 
     Nozzle 
     The nozzle  200  of the liquid dispensing spout  100  is removably attached to a front face  103  of the spout body  102  by plastic tabs  104  cantilevered from the top and bottom of the front face  103  of the spout body  102 . The nozzle  200  is thus not permanently attached but can be removed from the spout body  102  by depressing the tabs  104 . The tabs  104 , which can be deflected, “removably” attach the spout by engaging (latch into) small, substantially square or rectangular “windows”  202  located near the top surface  204  of the nozzle  200  and the bottom surface  205  of the nozzle  200 . The tabs  104  and windows  202  thus lock or engage the nozzle  200  to the front face  103  of the spout body  102 . 
     Those of ordinary skill in the art should know that a fluid is a substance that tends to flow or conform to the outline of its container. Liquids and gases are thus fluids. 
     As best seen in  FIGS. 5-8 , the nozzle  200  provides two, physically separate fluid conduits  221  and  223 , which carry air and liquid respectively in opposite directions, i.e, to and from the spout body  102  respectively. Liquid from the reservoir  101  enters the upper conduit  223  at a fuel inlet port  215  at the first end  208  of the nozzle  200 . Liquid exits the nozzle  200  from a fuel outlet port  217  located at the distal second end  210  of the nozzle  200 . 
     The lower conduit  221  carries air. It is defined by a convex surface having longitudinal edges joined to the bottom  205  of the nozzle  200 . The lower conduit carries air that enters the conduit  221  at the outlet end  210  of the nozzle  200 . Air flows inwardly through the lower conduit  221  and to the spout body  102 . Air is controllably flowed through the spout body  102  and into the reservoir  101  by one of the linked poppet valves  300  via the vent tube  600 , albeit after the vent tube  600  is evacuated by a small negative pressure created in the reservoir  101  by opening the liquid control poppet before the air control poppet. 
     Those of ordinary skill in the art should recognize that in an alternate embodiment, the fluid-carrying conduit  223  can be located below the air-carrying conduit  221 . Such an embodiment, however, loses advantages provided by the air-carrying conduit below the liquid-carrying conduit, at least one of which is improved air flow. As described below, momentum of the outwardly-flowing liquid stream above the air intake port  219  reduces the likelihood that liquid will be drawn into the air intake port. 
     Merriam-Webster&#39;s Dictionary defines “ovoid” as resembling the shape of an egg. “Ovate” on the other hand means having an outline like the longitudinal section of an egg with the basal end being broader. 
     As best seen in  FIG. 5 , the distal or second end  210  of the nozzle  200  has a substantially circular cross sectional shape. The lower, air conduit  221 , however, has convex-shaped an air inlet port  219  at the second end  210  of the nozzle  200 . 
     As best seen in  FIG. 6 , the first end  208  of the nozzle  208  is substantially ovate-shaped. It is attached to the substantially ovate-shaped front face  103  of the spout body  102  by the aforementioned tabs  104  and windows  202 . 
     At the first end  208  of the nozzle  200 , the air conduit  221  has a convex-shaped air outlet port  216 . As can be seen in  FIG. 3 , a substantially ovate-shaped gasket  209  between the first end  208  of the nozzle  200  and the front face  103  of the spout body  102  enables a substantially air-tight seal between the nozzle  200  and spout body  102  when the nozzle  200  is attached to the spout body  102  by the engagement of the tabs  104  and windows  202 . 
       FIG. 6  shows a slot  214  formed in the convex-shaped “top” surface of the outlet end or port  216  of the air conduit  221 . The slot  214  has a width, W 1 , selected to provide a clearance fit with a “web”  306  portion of the linked poppet valves  300 . 
     As described below, the web  306  holds the two linked poppet valves  302 ,  304  in a space-apart relation to each other. As described below, a flow path separator  322  extending from the web  306  fits over the slot  214 , effectively preventing liquid in the liquid conduit  223  from leaking into the air conduit  221 . 
     The liquid outlet port  217  and air inlet port  219  at the second end  210  are considered herein as being “enclosed” within a substantially circular “orifice” defining the second end  210  of the nozzle. That orifice also is considered to be a “closed curve,” which is of course a curve with no endpoints and which completely encloses an area. Each port  217 ,  219 , however has its own open area. As described below, the areas of the ports  217 ,  219  are not selected at random but are instead selected such that the ratio between them provides a laminar or nearly laminar flow of liquid flowing out of the liquid port  217 . 
     Similarly, the liquid inlet port  215  and the air outlet port  216  at the first end  208  of the nozzle  200  are considered as being “enclosed” within the substantially ovate-shaped first end  208 , which is also a closed curve. As shown in  FIG. 6 , however, the ports  215 ,  216  at the first, however, have their own corresponding open areas. 
     The liquid inlet port  215  at the first end  208  of the nozzle  200  has an area greater than the area of the liquid outlet port  217  at the second end  201  of the nozzle  200 . The reduction in area between the first end  208  and the second  210  of the nozzle  200  is provided by an intermediate, transition section  211 , which provides a second end  210  have a size and shape that can fit into a container or opening into which liquid such as gasoline needs to be dispensed. Stated another way, the intermediate section  211  reduces the area of the front face  103  of the spout body  102 , and which is required to accommodate the side-by-side poppets used in the spout body, to a size that fits into the gas tank inlet restrictors of many automobiles. 
     At the second end  210  of the nozzle  200 , the air inlet port  219  is purposefully located below the fluid outlet port  217 . Experimentation revealed that momentum of a liquid stream flowing out of the nozzle  200  at the second end  210  prevents or at least significantly reduces liquid being drawn into the air inlet port  219  during dispensing. The liquid stream momentum, however, will depend on its velocity. The liquid stream velocity will of course depend in part on the cross sectional area of the liquid outlet port  217  but will also depend on volumetric air flow rate into the reservoir  101 , inasmuch as the reservoir  101  is air tight or at least substantially air tight, the liquid stream output flow rate from the port  217  depends on the volumetric flow rate of air into the air inlet port  219 . The flow rate of air into and through the air into the reservoir  101  will thus depend on the area of the air inlet port  219 . 
     In the preferred embodiment, the area of the liquid inlet port  215 , the area of the air outlet port  216 , the area of the liquid outlet port  217 , the area of the air inlet port  219  and the lengths of the air and liquid conduits  221  and  223  respectively, were selected such that the gravitational flow rate from the liquid outlet port  217  was between about 2.0 and 2.5 gallons per minute and having a substantially laminar flow, i.e., a liquid outlet flow without pulsation. An optimum ratio of the liquid output port  217  area to the air input port  219  area was experimentally determined to be about four to one (4:1) for gasoline or other liquids having viscosities between about 0.5 centipoise and 1.5 centipoise. (Water has a viscosity of 1.0 centipoise.) Such a ratio (about 4:1) produced a liquid output flow rate substantially laminar and without pulsation, using an appropriately constructed and dimensioned vent tube  600 . 
     In an alternate embodiment of the nozzle, the areas of the liquid inlet port at the first end  208  of the nozzle  200  and the area of the liquid outlet port at the second end  210  of the nozzle are substantially the same, in which case, the intermediate section  211  is essentially straight. In such an alternate embodiment, the areas of the conduits and their respective openings can have the same or different cross sectional areas. 
     In other alternate embodiments, the cross sectional shapes of the air and liquid conduits and their respective openings are substantially circular, oval and rectangular. The shapes of the first and second ends of the spout can also be the same or similar shapes. 
     Linked Poppet Valves 
     Merriam-Webster&#39;s Dictionary defines “poppet” as a valve that rises perpendicularly to or from a mating seat. The valves commonly used in the combustion chambers of an internal combustion engine type are poppet valves. 
     The structure of the preferred linked poppet valves  300  comprising the liquid dispensing spout  100  is perhaps best seen in  FIGS. 3, 13, 14A, 14B and 19 . Understanding their operation, however, is assisted by reference to  FIGS. 9-11 . 
     As shown in  FIG. 3 , linked poppet valves  300  are located between the first end  208  of the nozzle  200  and the front face  103  of the spout body  102 . As best seen in  FIGS. 13, 14A and 14B , the linked poppet valves  300  comprise a liquid control poppet  302  and an air control poppet  304 . The liquid control poppet  302  controls the flow of liquid from the reservoir  101  into the nozzle  200 . The air control poppet  304  controls the flow of ambient air into the reservoir  101 . 
     Liquid can flow out of the reservoir  101  and into the liquid inlet port  215  of the liquid conduit  223  when the liquid control poppet  302  opens. Vent air can flow into the air inlet port  219  and through the air conduit  221  to the reservoir  101  when the air control poppet  304  opens. 
     In the preferred embodiment of the liquid dispensing spout  100 , the liquid poppet  302  opens before the air control poppet  304  opens. Similarly, when dispensing is stopped, the air control poppet  304  closes prior to the liquid control poppet  302 . Opening the liquid poppet  302  before opening the air control poppet  304  when dispensing liquid allows a vacuum to develop in the reservoir  101  during the time that the air control poppet is closed. The vacuum draws out of the vent tube  600 , liquid that might be trapped in the tube  600  when the reservoir  101  is rotated to dispense fuel, as shown in  FIGS. 25A and 25B . 
     The preferred embodiment of the liquid control poppet  302  has a shape resembling an egg, i.e., a substantially prolate-spheroid having opposing ends identified by reference numerals  308  and  309 . The shape of the preferred liquid control poppet  302  is perhaps best seen in  FIGS. 13 and 14 , as well as  FIG. 19B , which provides a top view of the linked poppet valves  300 . 
     A first or front end  308  of the first poppet  302  has a tapered portion  307 , which narrows the front end  308  inwardly to form a stem  310  and which helps liquid stream smoothly over the over the poppet  302 . The opposite, rear end  309  of the liquid control poppet  302  is also tapered to reduce eddy currents in the liquid. The stem  310  and the first, liquid control poppet  302  each have a central axis  324 ,  326 . The axes  324 ,  326  are preferably co-axial. 
       FIGS. 26-32  show various alternate embodiments of linked poppets  300 . Such alternate embodiments have front ends  308  and/or rear ends  309 , which are truncated or significantly flatter (e.g.,  FIGS. 26-28 and 31 ) than the front and rear ends of the lined poppet preferred embodiment. Alternate embodiments have O-rings that are offset from each other in different directions and different distances. Other alternate embodiments have valve stems with different cross sectional shapes, e.g.,  FIGS. 26, 27 and 28 . At least one alternate embodiment has a valve stem located between the poppets, i.e,  FIGS. 30 and 32 . 
     In preferred embodiments, the first end  308  of the liquid control poppet  302  has an O-ring groove  330  located in and circumscribing the tapered portion  307  of the liquid control poppet  302 . An O-ring  332  in the O-ring groove  330  essentially provides the liquid control poppet  302  with a “liquid sealing surface,” which when urged or biased against an appropriately shaped valve “seat” is able to prevent or stop liquid from flowing out of the reservoir  101 . In other words, the liquid control poppet  302  is closed when the O-ring  332  contacts a corresponding “seat”  125  inside the upper orifice  108  of the spout body  102 . As described below, a spring biases the valve stem  310  and the O-ring  332  against the seat  108  in the spout body  102 . 
     The far end or “distal end”  312  of the valve stem  310 , i.e., the end of the valve stem  310  furthest from the poppets  302 ,  304  comprises a fork-like clip  314 . The clip  314 , which comprises part of a linked poppet actuator  400 , is preferably embodied as two, spaced-apart and substantially parallel tines  316 ,  318 . 
     As best seen in  FIG. 13 , the tines  316 ,  318  of the preferred embodiment are substantially gutter-shaped. The far end  319  of each gutter-shaped tine  316  has a rectangular thru-opening or “window”  320 . Each window  320  receives a protuberance that extends radially from a “button”  406 , best shown in  FIG. 19A . Together, the gutter shape and windows  320  allow the tines  316 ,  318  to snap together and effectively grasp the button  406 , without requiring tools or equipment. 
     The second poppet  304  controls air flow between the spout  200  and reservoir  101 . As shown in  FIGS. 13 and 14A , the preferred embodiment of the second poppet  304  is essentially a short piston having an O-ring groove  334  that circumscribes the second poppet  304  near its first end  305 . Such a poppet is considered herein as being substantially cylindrical. It&#39;s first end  305  is also preferably chamfered  335 . A soft, compressible O-ring  336  in the groove  334  provides an air flow sealing surface when the second poppet is inside an appropriately shaped and sized chamber or applied against an appropriately sized and shaped “seat.” 
     The second poppet  304  has of course its own corresponding cross-sectional shape and central axis  326 . Inasmuch as the poppets  302 ,  304  move at the same time in substantially the same direction by the same distance, the central axes of the poppets  302  and  304  are preferably coplanar or at least substantially coplanar and at least substantially parallel to each other as well as the central axis  324  of the stem  310 . The substantial co-planarity and substantial parallelism of the axes means that the two poppets  302  and  304  and stem  310  travel the same distance, in the substantially same direction along substantially parallel to each other responsive to translation of the stem  310 . 
     For purposes of clarity, as used herein “coplanar” means lying in or on, the same geometric plane. It should also be construed as lying in or on, substantially the same plane because manufacturing tolerances and processes cannot guarantee that any two axes, O-ring grooves, O-rings or any other similar product are exactly the same. 
     The chamfer  335  on the second poppet  304  facilitates movement of the poppet  304  into and out of a tapered cylinder  112  formed in the spout body  102  and best seen in the cross section of the spout body  102  provided in  FIG. 12 . The tapered cylinder/airflow control chamber  112  has an air inlet, embodied as the lower orifice  110  in the spout body  102 . 
     As the O-ring  336  slides back and forth in the tapered cylinder  112 , which is considered herein to be an airflow control chamber, the soft O-ring  336  effectively lengthens the distance that the air control poppet  304  has to travel in the tapered cylinder  112 , relative to the distance that the liquid control poppet  302 , before the air poppet  304  is “open.” Stated another way, slight compression of the O-ring  336  for the air control poppet  304  in the tapered cylinder enables the liquid control poppet  302  to open and allow liquid to flow before the air control poppet  304  opens to such an extent that a volumetric air flow rate into the reservoir  101  is sufficient to let fluid out of the reservoir and nozzle  200  without pulsation. 
     The poppets  302  and  304  are mechanically coupled to each other by a web  306 . Both poppets  302 ,  304  and the web  306  are translated or “actuated” by a single valve stem  310 . In the preferred embodiment, the stem  310  extends from the front end or side  308  of the liquid control poppet  302 . 
     The web  306  has a thickness, which is less than the width, W 1  of the slot  214  formed in the “top” surface of the air conduit port  216  at the first end  208  of the nozzle  200 . The web  306  also has a flow path separator  322 , sized, shaped and arranged (configured) to cover the slot  214 . The flow path separator  322  thus has a width W 2  greater than the width, W 1 , of the slot  214 . The flow path separator  322  preferably has a concave curvature substantially the same as the convex curvature of the air conduit  221  in the nozzle  200  to provide a barrier for the slot  214 . In the preferred embodiment, the flow path separator is molded with the web, poppets and stem. In an alternate embodiment, however, the flow separator is clipped or snapped onto the web  306 . 
     For cost reduction purposes, the poppets  302 ,  304 , web  306 , stem  310  and flow path separator  322  are preferably formed using molded plastic and are a single unitary structure. The flow path separator can also be integral with or connected to the poppets  302 ,  304  themselves. 
     Plastics are known to have a tendency to “creep” or “cold flow” over time. The web  306  is thus constructed to have a relatively large width W 3  substantially equal to the length of the slot  214  in order to strengthen the web and usage-induced creep. 
       FIG. 10  is a perspective view of the front side or front face  103  of the spout body  102 .  FIG. 11  is a side view of the spout body  102 .  FIG. 12  is a cross sectional view of the spout body  102 . 
     The substantially ovate-shaped flange  106  on the front side or face  103  of the spout body  102  circumscribes two orifices  108  and  110 . The flange  106  thus mates with the substantially ovate-shaped first end  208  of the nozzle  200 . 
     In  FIG. 10 , the top “orifice”  108  has a short conic section that provides an “interface surface  125 ” that meets the O-ring  332  on the liquid control poppet  302 . The liquid control poppet  302  is closed when its O-ring  332  is seated against the interface surface  125 . 
     As best seen in  FIGS. 13, 14A and 14B , the linked poppets  302  and  304  are laterally separated from each other as well as “coupled” to each other by the web  306 . 
     Referring now to  FIG. 13  and  FIG. 14 , the liquid control poppet  302  has an O-ring groove  330  located adjacent the front end  308 . The O-ring  332  in the O-ring groove  330 , is sized and shaped to fit snugly into the O-ring groove  330  and provide a liquid sealing surface for the first poppet  302  that alternately makes contact with and separates from the mating surface  108  in the spout body  102 . 
     The air control poppet valve  304  has an air sealing surface, comprising a second O-ring  334  that fits into a correspondingly-sized O-ring groove  331 . The O-ring  334  and the air control poppet valve  304  extend into an elongated tapered air control chamber  112 , best seen in  FIG. 12 . The tapered air control chamber is preferably a tapered cylinder in the spout body  102  and accessed through the lower opening  110  in the spout body  102 . 
     As best seen in  FIG. 14B , the O-ring  332  and the air sealing surface provided by the O-ring  331  on the air control poppet valve lie in separate and different geometric planes the edges of which are identified by reference numerals  352  and  354 . Those two planes  352  and  354  are substantially parallel and purposefully separated from each other by a relatively small distance denominated herein as an O-ring offset spacing or distance  350 . 
     Because the O-rings are offset, the coupled-together linked poppet valves  300  open at different linear displacements of the valve stem  310 . The liquid poppet  302  opens to allow liquid to flow from a reservoir before the O-ring  332  of the air control poppet  304  separates from its mating air sealing surface  110  in the spout body  102  thereby allowing air to flow through the tapered cylinder  112 . Similarly, when the linked poppets  302 ,  304  are to be closed, the O-ring  332  of the liquid control poppet  302  contacts its “liquid control valve seat”  108  before the O-ring  334  of the air control poppet contacts, and seals off the tapered cylinder  112  before the liquid control poppet  302  closes. The staggered opening and closing allows a vacuum to be developed in the reservoir  101  before the air control poppet  304  opens. That vacuum draws out of the vent tube  600 , liquid that might be trapped in the vent tube  600  as the reservoir  101  is tilted. 
       FIG. 25A  shows the liquid dispensing spout  100  attached to the conventional gasoline can, i.e., reservoir  101 . The vent tube  600  extends into liquid  2502 . A column of liquid  2504  is in the tube  600 . 
     When the reservoir  101  is inverted or tipped to dispense the liquid, as shown in  FIG. 25B , some of the column of liquid  2504  will be “trapped” in the vent tube  600 . Liquid  2502  trapped in the vent tube  600  will prevent air from flowing through the tube  600  and into the reservoir  101 . Properly venting the reservoir  101  with an extended vent tube  600  thus requires removing trapped liquid  2504  from the vent tube  600 . 
     Offsetting the O-rings  332 ,  334  enables the linked poppet valves to open at different displacements of the valve stem  310 . Stated another way, the liquid control poppet  302  will open before the air control poppet  304  opens. Liquid will thus flow past the liquid control poppet  302 , from the reservoir  101 , before air can flow past the air control poppet  303  and into the reservoir  101 . Allowing liquid to flow out of the reservoir before air can flow in enables a vacuum to be developed inside the reservoir  101 . The vacuum so developed draws liquid trapped in the air inlet tube  600 , provided of course that the tube  600  is properly constructed as described below. The staggered openings of the liquid and air control poppets thus provides the spout  100  with the ability to siphon fuel or other liquid out of the vent tube  600  that would otherwise be trapped in the air pickup tube  600  as a fuel tank or other liquid reservoir to which the spout  100  is connected, is inverted. The reservoir  101  can thus be properly vented by air flowing in from the nozzle  200 . 
     Linked Poppet Valve Actuator 
       FIGS. 15-20  depict an actuator  400  for the linked poppet valves  300 . The actuator  400  comprises the aforementioned clip  314  on the distal end  312  of the valve stem  310  and a valve actuator block  402 , best seen in  FIG. 19A . 
     Referring again to  FIGS. 14A, 14B, 16 and 17 , the clip  314  portion of the linked poppet valve actuator  400  is comprised the aforementioned tines  316 ,  318  at the distal end of the valve stem  310 . Each tine  316 ,  318  has opposing first and second ends and a “window” or hole  320  located near the distal end, i.e., the end furthest from the poppet  302 . The window  320  in each tine  316 ,  318  is sized, shaped and arranged to fit around, i.e., receive, a protuberance  404  extending radially from the surface of a substantially frusto conically-shaped button  406 . The button  406  extends or projects substantially orthogonally from a substantially planar and annulus-shaped, spring receiving surface  408  that is on a first face  410  of the valve block  402 . An undercut  416  separates the button  406  from the spring receiving surface  408  so that the windows  320  in the tines  316 ,  318  can fully encircle the protuberances  404 . 
     The protuberances  404  and the windows  320  engage and lock each other together. The valve block  402  and the linked poppet valves  302 ,  304  are thus locked together. 
     As best seen in  FIG. 19B , a coil spring  420  fits over the valve stem  310 . The valve stem  310 , however, is first inserted through an orifice or hole  152  that extends horizontally through the spout body  102 . 
     One end of the spring  420  rests in the hole  152 . The valve stem travel limiter  154  is essentially a flat, rectangular pad, orthogonal to the hole  152  and contacts the receiving surface  408  when the valves are fully open. The opposite end of the spring  420  rests against the spring receiving surface  408  of the valve block  402 . 
     When the liquid dispensing spout  100  is assembled, the spring  420  is compressed between the spring receiving surface  408  and the valve stem travel limiter  154 . The spring  420  thus exerts compressive force against the spout body  102  and through a washer and O-ring for the valve block  402 . Since the valve block  402  is latched to the valve stem  310  by the protuberances  404  and clip  314 , the spring biases the poppet valves  302 ,  304  to a normally closed position. The position and functionality of the coil spring is best seen in  FIG. 9 , which is an isolated cross-sectional view. 
     When the actuator block  402  and button  406  are urged toward the rear face  150  of the spout body  102 , the valve stem  310  and poppets  302 ,  304  are urged away from the spout body  102 , toward the nozzle  200  and away from the valve sealing surfaces in the spout body  102 . Such movement of the valve stem compresses the spring, which applies a compressive force to the valve block  402  that also applies a tensile force to the valve stem  310 . 
     Child-Resistant Actuator 
     As stated above, the liquid dispensing spout  100  includes a child-resistant actuator  500 , best seen in  FIGS. 21, 22, and 23 . The child-resistant actuator  500  comprises the aforementioned travel limiter  154  portion of the spout body  102 , the aforementioned valve actuator block  402 , a fulcrum pin  502  and a generally U-shaped lever  504  that pivots on, or around the fulcrum pin  502 . 
     For purposes of the child-resistant actuator, the valve stem actuator block  402 , is considered as having two opposing faces  410 ,  412  and two opposing sides  414 ,  416 . The button  406  on the first face  410  engages and latches the valve stem clip  314 . 
     As described above and as can be seen in the figures, the liquid dispensing spout  100  is “operated” by moving the valve stem actuator block  402  toward the spout body  102 . The valve stem actuator block  402  movement is constrained by position of parallel legs  506  of a substantially U-shaped lever  504 , vis-à-vis the planar travel limiter  154  of the spout body  102 . 
     As best seen in  FIGS. 21, 22, and 23 , the lever  504  is mounted on the fulcrum pin  502 . The fulcrum pin  502  extends through a hole  420  that extends through the valve stem actuator block  402 , orthogonal to the sides  414 ,  416  of the block  420 . 
     In the preferred embodiment, the fulcrum pin  502  and the hole  420  have an interference fit between them, in which case the lever  504  pivots on the fulcrum pin  502 . In an alternate embodiment, the fulcrum pin  502  and the lever  504  have an interference between them; the lever  504  thus pivots in the hole  420 . 
     Regardless of how and where the lever  504  pivots, the lever  504  pivots or “rotates” through an angle of up to about ninety degrees, responsive to a user pushing upwardly or downwardly on an opposite, “user” end or tab  508  of the lever  504 . Stated another way, the lever  504  can be manipulated by a user&#39;s thumb, palm or finger to rotate the lever  504  on the fulcrum pin  503  through an angle of up to about ninety degrees. 
     The user end or tab  508  of the lever  504  extends through an opening or window in a cover for the valve stem actuator block. A coil “lever spring”  510  is “wrapped around” the fulcrum pin  502 . The opposite ends of the spring  510  exert force against the second face  412  into a cylindrical diagonal pock (not shown) of the valve stem actuator block  402  and the user end  508  of the lever  504  to bias the lever  504  be horizontal, substantially as shown in  FIGS. 21 and 22 . 
     The lever return spring  510  continuously biases the lever  504  to be horizontal such that the legs  506  are directed to toward the valve stem actuator block travel limiter  154  portion of the spout body  102 . When the legs  506  are horizontal, the valve stem actuator block  402  is prevented from moving toward the spout body  102 . Constraining the movement of the valve block actuator  402  by the legs of the lever  504  thus prevents the valve stem  310  and the poppets connected to it from being moved, preventing the poppets from being opened. Constraining the valve block actuator  402  also prevents pressure inside the reservoir  101  from “pushing” the poppets open. The child-resistant actuator thus prevents vapors in the reservoir  101  from escaping. 
     When the lever is pushed upwardly or in an alternate embodiment downwardly, the lever  504  and its legs  506  rotate around the fulcrum pin  502  to either a vertical or nearly vertical position, allowing the valve actuator block  402  to translate toward or into the spout body  102 . When the valve actuator block moves toward the spout body  102 , the valve stem  310  moves through the orifice in the spout body urging the poppets away from their sealing surfaces and allowing fluid to flow as well as air to enter the reservoir. 
     Those of ordinary skill in the art should recognize that the legs  506  of the lever  504  are preferably straight but can also be bent or curved. The length of the legs  506  also needs to be slightly less or shorter than the distance between the travel limiter  154  and the fulcrum pin  502 . 
     The two legs  506  are preferably the same length. In an alternate embodiment, however, the legs  506  can have different lengths but in such an embodiment, the travel limiter  154  has different-height surfaces such that a shorter leg  506  meets the travel limiter  154  “simultaneously” with a longer leg. 
     Those of ordinary skill in the art should also recognize that maximum travel of the valve actuator block  402  is possible when the lever  504  is rotated about 90 degrees around the fulcrum pin  502 . Lesser angular displacements will allow the valve actuator block to travel smaller distances decreasing the opening areas on the two poppets. 
       FIG. 34  shows an alternate embodiment of a child-resistant actuator  3400 . AN axially rotating cam  3401  enables and disables engagement of the valve actuator block with the valve stem. A rotatable tab  3402  on a front face  3404  of a push-button  3406 . The back face of the push-button  3406  abuts the valve actuator block. Rotating the tab  3402  enables and disables the push button, enabling and disabling the spout  100  accordingly. 
     In another embodiment, shown in  FIG. 35 , the legs  506  and tab  508  of the U-shaped lever  504  are separated from each other but mounted to work together. Stated another way, the U-shaped lever  504  is replaced by an L-shaped bracket  3402 . Two legs  3404 ,  3406  of the L-shaped bracket  3402  meet at or near a pivot point  3408  through which a fulcrum pin  3410  extends. The L-shaped bracket  3402  pivots on the fulcrum  3410 . A first leg  3406  of the L-shaped bracket  3402  abuts a substantially U-shaped actuator  3412 . The longer, second leg  3404  extends toward the travel limiter  154 . Depressing the actuator  3412  causes the separate L-shaped bracket  3402  to rotate on the fulcrum  3410 , “rotating” the second leg  3404  into or away from the travel limiter  154 . 
     In yet another embodiment shown in  FIG. 36 , the length of the valve stem  310  is increased to extend substantially through the spout body  102 . An actuator block  3602 , which can slide in the spout body  102 , has a front side  3604  that acts as a cam vis-à-vis the valve stem  310 . A spring-loaded, pivotally-mounted tab  3606  is configured to press against the back side  3608  of such an actuator block  3602 . Pushing the tab  3606  toward the poppets  302 ,  304 , drives the poppets  302 ,  304  away from their sealing surfaces and opening them. 
     Those of ordinary skill in the art should also recognize that the U-shaped lever  504  with two legs  506  can also be replaced by a lever having only one-leg, i.e., a one-legged lever, which is pivoted the same way on a fulcrum pin. Regardless of whether a one-legged or two-legged lever is used, the two legs  506  (or one leg) of the child resistant actuator  504  acts as a travel limit to stop the poppet valve  300  from translating and thus disengaging the air and fluid O-rings  334  and  332  from their corresponding sealing surfaces. Disengagement of the O-rings from their sealing surfaces results in contents of the reservoir  101  being released to the environment. 
     An ASTM standard requires a valve for fuel reservoirs to resist 20 psi. A leg of a child-resistant actuator as disclosed herein eliminates the need for a spring  420  to provide such functionality. The stiffness of the spring used with the child-resistant actuator can thus be reduced lowering the force required to open the valves and easier for a consumer to operate. 
     Vent Tube 
     Finally,  FIG. 24A  is a perspective view of a first embodiment of semi-rigid air inlet tube or vent tube  600 .  FIG. 24B  is cross-sectional view of the air inlet tube  600 . 
     The tube  600  has a first end  602  which is slid over a small diameter pipe nipple that extends downwardly from the spout body  102 . An opposing distal or second end  604  is separated from the first end  602  by a length L 2 . L 2  is chosen to be less than the inside vertical height of a liquid storage tank or reservoir  101  such that the second end  604  will be above the level of liquid in a storage tank when the tank is inverted to dispense liquid. See for example  FIGS. 25A and 25B . In an alternate embodiment, however, L 2  is selected to extend above the level of the liquid in the reservoir  101  when the reservoir  101  has been completely filled. 
     An interior channel  606  tapers in from the first end  602  toward the second end  604 . The tapering configuration, or optionally the configuration with a small opening at the distal end  610 , i.e., smaller than the remainder of the tube with parallel sides, improves the consistency of airflow into the tank. 
     If liquid enters the tube at the smaller opening at the end of the tube  610 , (undesirable but can happen) and drips into the tube, the cross section increases of expands the farther that the liquid droplet moves into the tube. The tapered cross section insures that airflow can flow around a droplet or droplets of liquid and maintain the flow of air into the tank to fill the negative pressure. Similarly, in an alternate embodiment shown in  FIG. 37 , the tube  601  is straight and has substantially parallel “sides”  603  with a small opening cap  605  at the distal end of the tube  601 . As a droplet enters the small opening, the droplet travels into the parallel wall-tube  601  of greater cross section than  610 , again allowing airflow to flow around the droplet. In  FIGS. 24 and 24B , the cone-shaped nozzle  608  at the second end has a small diameter opening  610 , the area of which is significantly less than the area of the opening at the first end  602 . The diameters at the first and second ends  612  and  614  respectively are thus also different. 
     The length and diameters at the opposite ends, and the taper, were experimentally determined to enable liquid trapped in the vent tube  600  when the vent tube is inverted, to be drawn out of the vent tube by a shallow vacuum created by liquid flowing out of the reservoir without air being allowed in, at the beginning of a pour. Stated another way, the length, L 2 , the taper and the diameters at each end are selected such that a vacuum created inside a liquid container when the liquid poppet valve opens prior to the air inlet valve, creates a negative pressure that will draw liquid in the vent tube out of the tube and back into the tank out. In a preferred embodiment, L 2  was about 5.25 inches. 
     Alternate Embodiments 
     Those of ordinary skill in the art should recognize that the structures disclosed above and as claimed hereinafter provide a dispensing spout for a liquid container that is child-resistant, enables the liquid to flow without liquid flow pulsation, ceases dispensing when the dispensing spout is submerged and which satisfies various other safety and functional requirements of governmental agencies. 
     In one alternate embodiment, the linked dual poppet valves have a stem  310  that is a hollow cylinder. An example of such an embodiment is shown in  FIGS. 26A and 26B . In another alternate embodiment, the stem  310  has a cross sectional shape reminiscent of the Arabic letter X, an example of which is shown in  FIGS. 27A and 27B . In yet another embodiment, the stem  310  has a cross sectional shape that is substantially rectangular, as shown in  FIGS. 28A and 28B . 
     In another embodiment, the stem  310  is attached to or extends from the web  306  that separates and links the poppets  302 ,  304 . Such an embodiment is depicted in  FIGS. 30 and 32 . 
     The leading and trailing edges of the liquid control poppet  302  can also be flattened. An example of a flattened leading edge is provided in  FIG. 28A . 
     In the preferred embodiment, the liquid sealing surface of the liquid poppet valve  302  is an O-ring  334  made of rubber or other soft, pliable material. In an alternate embodiment, the liquid sealing surface is a pliable material that is “over-molded” (or “overmolded”) a non-pliable material, molded to form the liquid control poppet. Similarly, in yet another alternate embodiment, the air sealing surface is a pliable material “over-molded” a non-pliable material, which is molded to form the air control poppet. 
     As used herein, the term, “lap” or “lapping” refer to processes by which two surfaces are worked or machined together, with or without abrasives, until a very close fit between them is produced. In an alternate embodiment, a portion of one or both of the liquid and air poppets  302 ,  304  is lapped with a mating surface in the spout body  102  to provide one or both sealing surfaces that are lapped to each other. 
     Alternate embodiments of the linked poppet valve actuator  300  and valve block exchange locations of the clip  314  on the valve block  402  and the engagement button  406  on the valve stem  310 . See for example  FIG. 29 . 
     The foregoing description is for purposes of illustration only. The true scope of the invention is set forth in the following claims.