Patent Description:
With most plastic water bottles, the cap body is made from a rigid or semi rigid material and the nozzle valve is made from a semi rigid semi flexible material. Typically, the material from which the cap body is made has a greater thermal linear expansion than the material from which the nozzle body is made. As a result, the nozzle valve can experience creep in size over time when subject to relatively extreme thermal conditions and hermetic or hydraulic sealing can be lost. As used herein, the terms hermetic and hydraulic are interchangeable. Creep can also result from mechanical events or the combination of thermal and mechanical events.

As here, where the nozzle body and cap body have different thermal linear expansion coefficients, hot and cold events or conditions are both relevant and, depending upon how parts interface, give rise to different issues of creep. Similarly, mechanical expansion and compression forces can give rise to creep. As compared to the cap body, the phenomenon of creep has a greater effect on the nozzle body due to the properties of the semi rigid semi flexible material from which it is made. Expanding or compressing a nozzle valve over time can cause the shape or size of the nozzle body to expand or contract. Further still, the process of creep is accelerated at elevated temperatures and humidity levels, for example, those that occur during a typical dishwasher cleaning and drying cycle. When coupled with mechanical expansion or compression forces acting on a nozzle body, elevated temperatures can drive creep to its mechanical limit altering the size or shape of the nozzle body. Conversely, reduced temperatures, experienced for example when a water bottle is placed in a freezer or when it is filled with relatively cold fluids, are less likely to result in creep because the nozzle body will stiffen and resist the effects of compression. Nonetheless, creep can still be a factor in reduced temperature conditions. In addition, stress can be molded into a component piece, particularly an injection molded part. Exposure to elevated temperatures can release such built-in stress. Often, such stresses cause a part to shrink. Any change in the shape or size of a part that is integral in forming a fluid seal can have a detrimental effect on the seal.

Typically, with current water bottles, when a nozzle valve and cap body are new, there is a press fit between mating parts that cause the semi rigid semi flexible valves to stretch and or compress to form hermetic seals by pressing against the mating surfaces of the cap body. If the parts are left in a stretched and or compressed condition for a period of time and subjected to relatively heightened thermal conditions, for example the wash/dry cycle of a dishwasher, the semi flexible semi rigid nozzle valve will deform or creep to the shape and the size of the mating surfaces of the relatively rigid cap. The net result is that the sealing surfaces lose their ability to press tightly against one another. In one state, the mating geometries are sized identically to one another. Parts that are sized identically will still form a hermetic seal provided the axial and radial alignment between parts does not change. However, when the nozzle valve is toggled from the open to the closed position, the parts will no longer have the same alignment and, therefore, will not form a hermetic seal. In a second state, the mating geometries have changed and the nozzle valve is larger than the mating surface of the cap body. As a result, the ability to form a hermetic seal between the mating parts is lost, regardless of the axial position of the parts.

<CIT> discloses a cap according to the preamble of claim <NUM>, for a bottle containing a drinkable beverage. The cap includes a cylindrical opening. A nozzle slides within a sleeve. A stop block is located inside the cap and includes an annular flange at the distal end. In a closed position, the distal end of the nozzle abuts the flat upper surface of the flange. A pair of limiting portions restrict movement of the sleeve.

<CIT> is directed to a container or bottle for storing and drinking liquids. The container includes a cap with a movable nozzle. A storage area is integral with the nozzle and is configured to hold liquid, powder or effervescent granules. When the nozzle is opened, the contents of the storage area fall into and mix with the liquid in the container body.

According to aspects of the present disclosure, an improved nozzle valve and an associated cap for a fluid container are described that address and resolve problems associated with thermal and mechanical creep. Improved methods and structures of forming a hermetic seal between the cap body and nozzle valve are described. These methods and structures address form and fit variations that occur over the life of the fluid container resulting from repeated exposure to elevated and reduced temperatures and mechanical expansion and compression events.

In one embodiment, a closure according to claim <NUM> comprising the improved nozzle valve and a cap member is intended to be used on a squeezable plastic water bottle. The cap dispenses the fluid contents of the bottle through a cylindrical nozzle valve that opens and closes orifices that direct the flow of the fluid as it is dispensed from the squeezable plastic water bottle. The nozzle valve slides upward and downward within a sleeve in the cap body to toggle between the open and closed modes. When the nozzle valve is pushed downward or inward it is in the closed mode. When the nozzle valve is in the upward or outward most position it is in the open mode.

According to aspects of the present disclosure, to address problems associated with thermally and/or mechanically induced creep over the life of a plastic squeeze bottle, the semi rigid semi flexible nozzle valve and rigid or semi rigid cap body require three sets of hermetic or hydraulic seals. A first set of sealing surfaces facilitates the up and down travel of the nozzle valve when moving from the open and closed positions. These sealing surfaces circumferentially extend around the outer cylindrical surface of the nozzle valve and interface with the inner wall of the sleeve, similar to the function of an O-ring. The nozzle valve is designed with thick wall sections proximate the sealing members to reduce the effects of material creep. Compared to a thinner wall section, the shape memory of a thicker wall section is retained longer. At elevated temperatures, i.e., those of a dishwasher, the cap body and sleeve material expands more than the material of the nozzle valve due to differences in the thermal linear expansion of the materials of the nozzle valve and cap body. The larger thermal expansion of the cap body and sleeve reduces the mechanical force each part imparts against the other and thereby reduces the stresses that cause creep. In a reduced temperature scenario, although the cap and sleeve may contract to a greater degree compared to the nozzle valve, the stiffening of the nozzle valve material inhibits the effect of creep.

The second and third set of sealing surfaces are at the bottom inner diameter and outer diameter of the movable nozzle valve, respectively, and are required to form a hermetic or hydraulic seal when in the closed mode. The inner diameter seal is formed by the distal end of the nozzle valve stretching over a larger diameter cylindrical plug located at the distal end of the sleeve of the cap body. The distal end of the nozzle valve utilizes a thin wall construction because it must not cause frictional forces that hinder the upward and downward travel of the nozzle valve when the user is toggling between the open and closed positions of the nozzle valve. Because it is thinner, it is more susceptible to the effects of creep. In one embodiment, the inner surface of the distal end of the nozzle valve interfaces with the outer surface of the plug at the distal end of the sleeve and the larger diameter outer surface of the plug imparts a mechanical expansion force on the inner diameter surface of the distal end of the nozzle valve. This mechanical stress will cause the nozzle valve material to creep. Exposure to elevated temperature events over time will accelerate the creep. The result of the creep is that the distal end of the nozzle valve will assume a larger diameter. The larger diameter may or may not form a seal when the nozzle valve is in a closed position. However, the nozzle valve will leak when subjected to colder temperatures that cause the cap body to shrink more than the nozzle valve.

A third set of sealing surfaces are formed between the bottom outer diameter of the nozzle valve and a mating surface of the cap body. More particularly, in one embodiment, a cylindrical channel is formed in the cap body that defines an inner surface and an outer surface. When the valve body is in the closed position, the bottom or distal end of the valve body is seated in the channel with the inner diameter of the valve body mating with the inner surface of the channel as described above in connection with the second set of sealing surfaces, and the outer diameter of the valve body mating with the outer surface of the channel (a third set of sealing surfaces). Preferably, the outer surface of the channel and the outer surface of the valve body are configured to force the outer surface of the valve body radially inwardly. In turn, this forces the inner surface of the valve body into engagement with the inner surface of the channel. The radially inward compressive force combats the mechanical expansion force of the outside surface of the plug. In addition, when either hot or cold thermal events happen, the outer diameter sealing surface of the valve body in contact with the outer surface of the channel of the cap body will maintain its hermetic or hydraulic seal and, in addition, force the inner diameter surface of the nozzle valve to compress and maintain its pressure against its mating surface of the cap body to form an affective hermetic or hydraulic seal. Thus, even if some creep were to cause expansion of the shape of the distal end of the valve body, the interface between the outer surface of the channel and the outer surface of the distal end of the nozzle valve counteract the creep and create at least one and preferably two hermetic seals.

Advantageously, the second surface of the distal end of the sleeve is angled relative to the longitudinal axis of the sleeve.

Advantageously, the outer surface of the distal end of the nozzle valve is angled relative to the longitudinal axis of the sleeve.

Advantageously, the cap body further comprises an anti-spill member positioned in the hollow body of the valve.

Advantageously, the cylindrical sleeve is made from polyethylene and the nozzle valve is made from at least one of urethane, silicone, natural rubber, synthetic rubber and polyimide.

Advantageously, the coefficient of thermal linear expansion of the cylindrical sleeve is greater than the coefficient of thermal linear expansion of the nozzle valve.

Advantageously, the difference in the coefficient of thermal linear expansion for the cylindrical sleeve and the nozzle valve is approximately <NUM> (<NUM> inches) at <NUM> (one-hundred-fifty degrees Fahrenheit).

Advantageously, the body of the nozzle valve has a thickness, and the thickness of the body is greater proximate the at least one seal member than at the distal end of the valve body.

The cap body further comprises a radially outwardly extending lip positioned at the distal end of the sleeve, the lip comprising the first and second surfaces of the distal end of the sleeve and forming a channel, and wherein the distal end of the valve body nests in the channel in the closed position.

This same nozzle valve may optionally contain structure that acts as a self-sealing valve within the said cylindrical nozzle. The self-sealing valve acts as a spill deterrent when the cylindrical nozzle is in the open mode.

The Summary of the Invention is neither intended nor should it be construed as being representative of the full extent and scope of the present invention.

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the general description of the invention given above and the detailed description of the drawings given below, explain the principles of these inventions.

In certain instances, details that are not necessary for an understanding of the invention or that render other details difficult to perceive may have been omitted. It should be understood, of course, that the invention is not necessarily limited to the particular embodiments illustrated herein.

<FIG> discloses one embodiment of a cap structure <NUM> that is intended to be used on a squeezable plastic water bottle <NUM>. The cap structure minimally comprises two parts: a body <NUM> and a nozzle valve <NUM>. The bottle <NUM> may comprise a variety of shapes. According to aspects of the present disclosure, the bottle <NUM> is generally cylindrical in shape having a longitudinal axis that extends through the nozzle <NUM>. Other bottle shapes and configurations are within the scope of the present disclosure.

With reference to <FIG>, the cap body <NUM> is generally cylindrical in nature and sized to form a hermetic seal across the open neck <NUM> of bottle <NUM>. A sealing surface <NUM> is formed between the cap <NUM> and bottle <NUM> when the screw threads <NUM> engage mating features <NUM> of the bottle neck <NUM>. The cap <NUM> dispenses the fluid contents of the bottle through the proximal end <NUM> of a cylindrical nozzle valve <NUM> that acts to open and close orifices <NUM> (<FIG> and <FIG>) that direct the flow of the fluid as it is dispensed from the squeezable plastic water bottle <NUM>. The cylindrical nozzle valve <NUM> is toggled from the open position illustrated in <FIG> and closed position illustrated in <FIG> by the operator. If the nozzle valve <NUM> is pushed downward or inward it closes or if it is pulled upward or outward it opens. In this configuration, the motion of the nozzle valve <NUM> is along the longitudinal axis of the bottle <NUM>.

According to aspects of the present disclosure, the cap body <NUM> is rigid or semi rigid in nature and can be made from any number of rigid or semi rigid materials, for example, impact resistant thermoplastic or impact resistant polyethylene such as high-density polyethylene ("HDPE") and low-density polyethylene ("LDPE"). In contrast, the cylindrical nozzle valve <NUM> is made from a semi flexible semi rigid material, for example, thermoplastic elastomers (TPE) such as urethane, silicone, natural rubber, synthetic rubber or polyimide, because the soft properties of these materials are good for accommodating surface imperfections and a press fit required in forming effective hermetic or hydraulic seals. Due to the material from which it is made, the cap body <NUM> has a coefficient of thermal linear expansion that is larger than the coefficient of thermal linear expansion of the nozzle valve <NUM>. Conversely, due to the material from which it is made, the nozzle valve <NUM> has a coefficient of thermal linear expansion that is less than the coefficient of thermal expansion of the cap body <NUM>. In addition, the semi flexible semi rigid materials of the valve body <NUM> accommodate a user that might tug on the nozzle valve <NUM> with his teeth to pull it upward into the open mode while taking a drink.

According to the present invention, the nozzle valve <NUM> is configured with one or more sealing members <NUM> formed around the exterior surface, for example, in an O-ring geometry (<FIG> and <FIG>), that form a hermetic seal by pressing against the inner surface <NUM> of a sleeve <NUM> formed in the cap body <NUM> in both the open and closed modes of the plastic cap <NUM>. The sleeve <NUM> includes one or more orifices <NUM> that extend through the wall of the sleeve and permit fluid to flow through the sleeve and out the proximal end of the nozzle valve <NUM> when the nozzle valve <NUM> is not in the closed position. The bottom or distal end of the nozzle valve <NUM> defines an inner surface <NUM> and an outer surface <NUM>. The thickness of the nozzle valve <NUM> between the surfaces <NUM> and <NUM> at the distal end of the nozzle valve <NUM> is relatively thin, and preferably thinner than the thickness of the valve <NUM> proximate the sealing members <NUM>. At least one ear <NUM> projects radially outwardly from the valve body <NUM> and is disposed within at least one orifice <NUM>. Preferably, the nozzle valve comprises at least one ear <NUM> positioned in two different orifices <NUM>. A plug <NUM> closes the distal end of the cylindrical sleeve <NUM> and a radially outwardly projecting lip <NUM> is formed radially outwardly from the plug <NUM> at the bottom or distal end of the cylindrical sleeve <NUM>. A channel <NUM> is formed in the lip <NUM> and defines an inner surface <NUM> and an outer surface <NUM>. The distal end of the nozzle valve <NUM> forms a hermetic seal at the bottom inner diameter surface <NUM> and bottom outer diameter surface <NUM> by pressing against surfaces <NUM> and <NUM> (<FIG>) of the cap body <NUM>, respectively, as shown in <FIG>. In preferred embodiments, surface <NUM> is cylindrical, polished and molded without draft. The reason it is preferable that surface has no draft is to maximize the length of contact between surfaces <NUM> and <NUM> while the nozzle valve is sliding from the open position to the closed position. When in a closed position, the bottom surface <NUM> of the nozzle valve <NUM> may engage the bottom surface <NUM> of the channel, as shown in <FIG>. Alternatively, the bottom <NUM> of the channel may be spaced from the bottom <NUM> of the valve body <NUM> with the surfaces <NUM> and <NUM> could be sized differently, having a longer dimension parallel with the longitudinal axis of the bottle.

According to aspects of the present disclosure, the diameter of surface <NUM> is sized larger than the diameter of surface <NUM> (<FIG>) of the nozzle valve <NUM> to create a press fit between the flexible nozzle valve and the more rigid cap body. In one embodiment, the diameter of surface <NUM> is <NUM> (<NUM> inches) larger than the diameter of surface <NUM>. When surface <NUM> of the nozzle valve is pushed over surface <NUM> of the cap body it stretches to form a hermetic seal between the interfering surfaces. In a preferred embodiment, the valve nozzle is stretched approximately but not limited to <NUM>%. It should also be noted that the wall thickness of the nozzle valve between surfaces <NUM> and <NUM> is small or thin enough to allow the users to stretch surface <NUM> across surface <NUM> without requiring excessive force to be supplied by the user when toggling the nozzle valve between the open mode to the closed mode. Furthermore, surface <NUM> of the nozzle valve presses against surface <NUM> of the cap body to form another hermetic sealing surface and to wedge or force the inner surface <NUM> of the nozzle valve <NUM> more tightly against surface <NUM> of the cap body. In a preferred embodiment, the distal end of the nozzle valve <NUM> and the channel <NUM> are substantially cylindrical and the outer surface <NUM> of the channel <NUM> is configured to press the outer surface <NUM> of the distal end of the nozzle valve <NUM> radially inwardly such that the inner surface <NUM> of the distal end of the nozzle valve <NUM> forms a sealed engagement with the inner surface <NUM> of the channel <NUM>. Simultaneously, the outer surface <NUM> of the of the channel <NUM> forms a sealed engagement with the outer surface <NUM> of the distal end of the nozzle valve <NUM>. Alternatively, the outer surface <NUM> of the distal end of the nozzle valve <NUM> may be configured to interface with the outer surface <NUM> of the channel to achieve the same radially inwardly directed force.

The material creep of the semi flexible nozzle valve <NUM> is exaggerated by the fact that the mating parts, the nozzle valve <NUM> and the sleeve <NUM>, have two different coefficients of thermal linear expansion. In a preferred method of construction, the cap body <NUM> is made from a polyethylene resin with a coefficient of linear thermal expansion of <NUM> / m °C (<NUM> micro inch / inch Fahrenheit) and the nozzle valve <NUM> is made from a thermoplastic urethane with a coefficient of linear thermal expansion of <NUM> / m °C (<NUM> micro inch / inch Fahrenheit). This difference can result in a relative difference in linear expansion of <NUM> (. <NUM> inches) across the geometry of features <NUM> and <NUM> assuming a dishwasher temperature of <NUM> (<NUM> F) and a diameter of <NUM> (. <NUM> inches), which is a preferred structure of surface <NUM>. In other words, surface <NUM> which stretches surface <NUM> when the nozzle valve <NUM> is in the closed position, expands <NUM> (. <NUM> inches) more than the semi flexible semi rigid nozzle valve <NUM> would grow when subjected to the same elevated temperature of <NUM> (<NUM>° F). In addition, at the elevated temperatures discussed, the nozzle valves <NUM> have a greater tendency to lose their elastic memory and thereby dimensionally creep to a larger or expanded shape or diameter. When the bottle cap <NUM> cools down to room temperature from the elevated temperatures of the dishwasher, the mating parts will not be sized the same as before the extreme temperature event. The mating surface <NUM> and <NUM> will either be sized identically to one another such there is no longer a pressing between them or there will be a gap between the sealing surfaces <NUM> and <NUM> depending on the number of dishwashing cycles and the age of the parts. Furthermore, as these same parts are subjected to freezing temperatures, surface <NUM> with the larger coefficient of linear thermal expansion will shrink more than the nozzle valve sealing surface <NUM> which will create a gap between sealing surfaces <NUM> and <NUM>. The net result is that the interface at surfaces <NUM> and <NUM> will leak absent the presence and influence of sealing surfaces <NUM> and <NUM>.

To assist in addressing the foregoing issue, in a preferred embodiment, sealing surface <NUM> (<FIG> and <FIG>) of the cap body is angled to wedge or force the inside surface <NUM> of the nozzle valve against surface <NUM> of the cap body by pressing on the circumference <NUM> of the nozzle valve <NUM>. The radially inwardly directed force can be enhanced or varied by the altering the shape of surface <NUM> and/or the complementary surface <NUM>. As illustrated in <FIG> and <FIG>, the surfaces <NUM> and <NUM> are angled or slanted to press or force the distal end of the valve <NUM> radially inwardly. As will be appreciated by those of ordinary skill in the art after review of the present disclosure, other geometric shapes can be substituted for the angled surfaces <NUM> and <NUM> with the same result, and such alternative configurations are deemed within the scope of the present disclosure. For example, one surface (<NUM> or <NUM>) could be aligned generally parallel with the longitudinal axis of the nozzle valve <NUM>, and the other surface could be angled relative to the longitudinal axis of the nozzle valve <NUM>. The surface generally parallel to the longitudinal axis would be substantially cylindrical while the surface disposed at an angle relative to the longitudinal axis would be frusto-conical in shape. This strategy accounts for and is tolerant of the effects at the elevated temperatures within a dishwasher that produce creep in the nozzle valve because outer surface <NUM> and inner surface <NUM> trap surfaces <NUM> and <NUM> between them with enough force to keep sealing surfaces in contact and without causing creep in the distal end of the nozzle valve <NUM> between surfaces <NUM> and <NUM> of the semi rigid semi flexible nozzle valve <NUM>. In other words, if the nozzle valve is subject to multiple thermal events, such as numerous dishwasher cycles, with the nozzle valve <NUM> in the closed position, the tendency of the diameter of the distal end of the nozzle valve <NUM> to increase to the diameter size of the inner surface <NUM> of the channel <NUM> is counteracted by the presence of the interface between the outer surface <NUM> of the channel <NUM> and the outer surface <NUM> of the nozzle valve <NUM> which acts to prevent expansion of the diameter of the distal end of the nozzle valve. Similarly, if the nozzle valve is in the open position during multiple thermal events, even if the distal end did tend to enlarge over time, the presence and operation of the outer surface <NUM> of the channel <NUM> acting on the outer surface <NUM> of the distal end of the nozzle valve will compel the inner surface <NUM> of the distal end of the nozzle valve into contact with the inner surface <NUM> of the channel <NUM>.

When analyzing creep and size variations of the sealing members <NUM> of the nozzle valve <NUM>, previous discussions do not apply. In this case, the geometry of the body of the nozzle valve was selected to keep part stresses below the level required for plastic deformation of the semi rigid semi flexible nozzle valve <NUM>. The wall thickness of the nozzle valve between the geometry of the sealing member <NUM> and surface <NUM> of <FIG> is increased such that internal stresses will not exceed the threshold of plastic deformation at or below room temperature. A thicker wall section also maintains shape memory longer compared to a thinner wall section. Thicker wall sections are permissible in this area of the nozzle valve <NUM> because the frictional forces experienced by the user when toggling the nozzle valve open and closed are a small percentage of the radial force that compresses the sealing members <NUM> against surface <NUM> of the cap body <FIG>.

Furthermore, when the first sealing features <NUM> are subjected to the elevated temperatures of a dishwasher, the cap body surface <NUM> will expand to a larger diameter than the nozzle valve <NUM> due to the larger coefficient of linear thermal expansion of the cap body material. More specifically, the diameter of surface <NUM>, which preferably is <NUM> (. <NUM> inches), will be <NUM> (. <NUM> inches) larger than the O-ring geometry of the first sealing features <NUM> at the elevated temperatures of a dishwasher. The net effect is that the sealing features <NUM> will be less likely to be affected by creep because there is less compression of the sealing surfaces <NUM> of the nozzle valve against the surface <NUM> of the cap body at the elevated temperatures that are likely to cause creep.

According to aspects of the present disclosure, the valve <NUM> may optionally include a self-sealing valve <NUM> as shown in <FIG> that acts as a spill deterrent when the cap is in the open mode (<FIG>) and the bottle is tipped over. Examples of such an anti-spill valves are available from Aptar, Inc. , Crystal Lake, Illinois. <FIG> shows an example of a section view of a generally accepted structure of a plastic cap without a self-sealing valve. A cap body B and a movable nozzle N are illustrated. Exemplary embodiments of a movable nozzle without a self-sealing valve are disclosed in <CIT> and <CIT>.

This self-sealing valve <NUM> is housed within the nozzle valve <NUM> and requires a different method of forming a hermetic seal between the nozzle valve <NUM> and cap body <NUM> that is generally understood in the market place for plastic caps that do not incorporate a self-sealing valve <NUM>.

According to aspects of the present disclosure, an alternative embodiment of the valve body <NUM> is illustrated in <FIG>. As shown, the exterior of the valve body <NUM> optionally includes a stabilizing feature <NUM>. This feature provides stability to the movement of the nozzle valve <NUM>, particularly preventing or reducing rocking that would cause axial misalignment of the nozzle valve relative to the sleeve due to heavy side loads.

Claim 1:
A closure for a container that is adapted to hold a fluid for dispensing and has an opening, comprising:
(a) a cap member (<NUM>) mountable to the container (<NUM>) and enclosing the opening, the cap member having a cylindrically walled sleeve (<NUM>) forming an outer opening in the cap member (<NUM>), and at least one orifice (<NUM>) formed in the sleeve (<NUM>);
(b) a movable nozzle valve (<NUM>) having a generally cylindrical hollow body (<NUM>) disposed for longitudinal movement within the cylindrically walled sleeve (<NUM>) between an open position to permit flow of a fluid through said hollow body (<NUM>) from the container (<NUM>) and a closed position to prevent flow of a fluid through the hollow body (<NUM>), the hollow body (<NUM>) having at least one seal member (<NUM>) projecting radially outwardly from an exterior surface and engaging the cylindrically walled sleeve (<NUM>), the hollow body (<NUM>) having an ear (<NUM>) projecting radially outwardly and received in the at least one orifice (<NUM>) to define a stop member for limiting movement of the hollow body (<NUM>) within the sleeve (<NUM>) between the open and closed positions; wherein
the cap member (<NUM>) has a radially outwardly extending lip (<NUM>) formed at the distal end of the sleeve (<NUM>), and wherein the at least one orifice (<NUM>) is formed in the sleeve (<NUM>) between said outer opening and the lip (<NUM>), the hollow body (<NUM>) having a distal end with an inner and outer surface;
characterized in that the cylindrically walled sleeve (<NUM>) forms the outer opening in the cap member (<NUM>) at the proximal end of the sleeve (<NUM>),
in that a channel (<NUM>) is formed in the lip (<NUM>), the channel (<NUM>) defining an inner surface (<NUM>) and an outer surface (<NUM>),
wherein the distal end of the hollow body (<NUM>) nests within the channel (<NUM>) when the valve is in the closed position, and the inner surface of the distal end of the hollow body (<NUM>) engages said inner surface of the channel (<NUM>) and the outer surface of the distal end of the hollow body (<NUM>) engages the outer surface of the channel (<NUM>) to form a seal between said distal end of the hollow body (<NUM>) and the channel (<NUM>).