The present invention relates generally to fluid containers and, more particularly, to closure mechanisms for drinking bottles such as sports and water bottles. Specifically, the present invention relates to pop-up type valve assemblies for fluid container closure mechanisms.
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.
According to aspects of the present disclosure, an improved nozzle valve and 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, the improved nozzle valve and cap are 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.
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. Moreover, reference made herein to “the present invention” or aspects thereof should be understood to mean certain embodiments of the present invention and should not necessarily be construed as limiting all embodiments to a particular description. The present invention is set forth in various levels of detail in the Summary of the Invention as well as in the attached drawings and the Detailed Description of the Invention and no limitation as to the scope of the present invention is intended by either the inclusion or non-inclusion of elements, components, etc. in this Summary of the 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.
It should be understood that the drawings are not necessarily to scale. 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.
With reference to
According to aspects of the present disclosure, the cap body 6 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 8 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 6 has a coefficient of thermal linear expansion that is larger than the coefficient of thermal linear expansion of the nozzle valve 8. Conversely, due to the material from which it is made, the nozzle valve 8 has a coefficient of thermal linear expansion that is less than the coefficient of thermal expansion of the cap body 6. In addition, the semi flexible semi rigid materials of the valve body 8 accommodate a user that might tug on the nozzle valve 8 with his teeth to pull it upward into the open mode while taking a drink.
According to aspects of the present disclosure, the nozzle valve 8 may be configured with one or more sealing members 26 formed around the exterior surface, for example, in an O-ring geometry (
According to aspects of the present disclosure, the diameter of surface 42 is sized larger than the diameter of surface 34 (
The material creep of the semi flexible nozzle valve 8 is exaggerated by the fact that the mating parts, the nozzle valve 8 and the sleeve 30, have two different coefficients of thermal linear expansion. In a preferred method of construction, the cap body 6 is made from a polyethylene resin with a coefficient of linear thermal expansion of 120 micro inch/inch Fahrenheit and the nozzle valve 8 is made from a thermoplastic urethane with a coefficient of linear thermal expansion of 85 micro inch/inch Fahrenheit. This difference can result in a relative difference in linear expansion of 0.002 inches across the geometry of features 34 and 42 assuming a dishwasher temperature of 150 F. and a diameter of 0.750 inches, which is a preferred structure of surface 42. In other words, surface 42 which stretches surface 34 when the nozzle valve 8 is in the closed position, expands 0.002 inches more than the semi flexible semi rigid nozzle valve 8 would grow when subjected to the same elevated temperature of 150° F. In addition, at the elevated temperatures discussed, the nozzle valves 8 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 2 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 34 and 42 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 34 and 42 depending on the number of dishwashing cycles and the age of the parts. Furthermore, as these same parts are subjected to freezing temperatures, surface 42 with the larger coefficient of linear thermal expansion will shrink more than the nozzle valve sealing surface 34 which will create a gap between sealing surfaces 34 and 42. The net result is that the interface at surfaces 34 and 42 will leak absent the presence and influence of sealing surfaces 36 and 44.
To assist in addressing the foregoing issue, in a preferred embodiment, sealing surface 44 (
When analyzing creep and size variations of the sealing members 26 of the nozzle valve 8, 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 8. The wall thickness of the nozzle valve between the geometry of the sealing member 26 and surface 46 of
Furthermore, when the first sealing features 26 are subjected to the elevated temperatures of a dishwasher, the cap body surface 28 will expand to a larger diameter than the nozzle valve 8 due to the larger coefficient of linear thermal expansion of the cap body material. More specifically, the diameter of surface 28, which preferably is 0.950 inches, will be 0.0025 inches larger than the O-ring geometry of the first sealing features 26 at the elevated temperatures of a dishwasher. The net effect is that the sealing features 26 will be less likely to be affected by creep because there is less compression of the sealing surfaces 26 of the nozzle valve against the surface 28 of the cap body at the elevated temperatures that are likely to cause creep.
According to aspects of the present disclosure, the valve 8 may optionally include a self-sealing valve 10 as shown in
This self-sealing valve 10 is housed within the nozzle valve 8 and requires a different method of forming a hermetic seal between the nozzle valve 8 and cap body 6 that is generally understood in the market place for plastic caps that do not incorporate a self-sealing valve 10.
According to aspects of the present disclosure, an alternative embodiment of the valve body 8 is illustrated in
While various embodiments of the present invention have been described in detail, it is apparent that modifications and alterations of those embodiments will occur to those skilled in the art. However, it is to be expressly understood that such modifications and alterations are within the scope and spirit of the present invention, as set forth in the following claims. Other modifications or uses for the present invention will also occur to those of skill in the art after reading the present disclosure. Such modifications or uses are deemed to be within the scope of the present invention.
The present application claims the benefit, under 35 U.S.C. § 119(e), of U.S. Provisional Application Ser. No. 62/398,728 filed Sep. 23, 2016 entitled “Sports Bottle Cap,” the entirety of which is incorporated herein by this reference.
Number | Date | Country | |
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62398728 | Sep 2016 | US |