Patent Description:
Containers can be used to store various contents, such as liquids. Some containers are designed to maintain the temperature of their contents, be they hot or cold. Vacuum flasks are commonly used as insulating storage containers. Typically, two concentric containers are joined at the neck, and the intervening gap is at least partially evacuated of air. The vacuum gap reduces heat transfer between the container contents and the environment. However, vacuum flasks are still prone to heat transfer via their lids or sealing mechanisms. During prolonged storage, heated contents are prone to cooling. Air space within the vessel also cools, generating a vacuum which may make removal of the container lid difficult.

The present invention provides a lid for an insulated container, according to claim <NUM>. The development of a vacuum in the interior compartment of the insulated container draws a force on the flexible gasket, thereby reducing pressure in the diaphragm chamber. The negative pressure in diaphragm chamber is back-filled with external air, which enters the lid via the air channels. The lid may then be removed without excessive vacuum forces.

All figures are drawn approximately to scale, however other relative dimensions may be used without departing from the scope of this disclosure.

Insulated containers, such as vacuum flasks are designed to maintain the temperature of their contents over time. However, such containers are prone to thermal compromise via the interface between the container body and a lid. The lid may act as a heat sink, allowing heated contents to cool over time, resulting in the generation of a vacuum in the otherwise sealed inner compartment of the vessel. The resulting vacuum may make removal of the container lid challenging, even causing vapor lock in the most extreme examples. While some insulated containers are ventilated, allowing outside air into the vessel is a less than ideal solution, as this may exacerbate cooling of the contents, and typically requires relatively small vents which may leak and are difficult to clean. One such approach is shown in <CIT>, which discloses a lid according to the preamble of claim <NUM>. Therein, a diaphragm is positioned so as to extend inwards into the container upon a vacuum developing. However, this requires the lid to engage with outer threads of the container so that the only seal is formed at the top of the container. This may reduce the fidelity of the seal when the lid is screwed onto the container.

Additionally, wider insulated vessels, such as canisters, may generate a gasket friction problem as a result of the increased surface area condition between the lid and the vessel. Even in the absence of venting and/or cooling issues, the torque required to open a canister may be high, simply based on gasket friction. In general, people may incorrectly blame vacuum for problems with opening storage canisters when the real problem is increased friction, or a combination of vacuum and friction. Either way, the result is a sealed vessel that is difficult or impossible to open.

For example, <FIG> shows illustrations of insulated canister assemblies <NUM> and <NUM>. Insulated canister assemblies <NUM> and <NUM> are configured to store liquids or other contents, and to sustain temperature differences between contents sealed within the assembly and the environment. Lid <NUM> is configured to reversibly couple to container body <NUM>, via rotation of lid <NUM> about a central axis which may enable the insulated canister assembly <NUM> to be closed and opened or partially opened such that lid <NUM> remains partially attached to container body <NUM>. For instance, a user may screw lid <NUM> in a clockwise direction to close insulated canister assembly <NUM> and rotate lid <NUM> in a counterclockwise direction to open or partially open insulated canister assembly <NUM>. However, other opening or closing techniques may be used, in other examples.

Container body <NUM> may be made from stainless steel, or any other suitable material for an insulated canister assembly. Container body <NUM> includes a base <NUM> and a top <NUM>. Top <NUM> includes an opening <NUM> which may be configured to receive lid <NUM>. Opening <NUM> may provide access to central cavity <NUM> when lid <NUM> is not coupled to container body <NUM>, allowing materials to be added to and/or withdrawn from container body <NUM>.

Canister assembly <NUM> is shown with container body <NUM> detached from lid <NUM>, allowing container mating complements <NUM> to be viewed. In this example, container mating complements <NUM> include sealing protrusions rather than threads. The sealing protrusions are shown arranged in a circumferential path (e.g., helical path) around an inner container surface <NUM>. Specifically, the sealing protrusions may trace a path around the inner container surface that corresponds to a thread path <NUM> around lid <NUM>. By utilizing sealing protrusions, rather than threads, a pathway from central cavity <NUM> to the exterior of the canister assembly may be generated when the lid <NUM> is partially unscrewed from container body <NUM>. In this way, liquid contents within central cavity <NUM> may be poured out without having to fully remove lid <NUM>.

The complimentary thread paths facilitate tight and robust sealing between container body <NUM> and lid <NUM> when lid <NUM> is attached to (e.g., screwed onto) the container body <NUM>. In the closed configuration, as shown for canister assembly <NUM>, container mating complements mate and seal with thread path <NUM>, thus joining lid <NUM> with container body <NUM>. In this way, liquid or other contents in container assembly <NUM> are sealed there within.

Container mating complements <NUM> are raised such that they extend inward, towards a central axis of container body <NUM>. Specifically, in one example, the sealing protrusions may be in the shape of a dome (e.g. hemispherical, semi-hemispherical, etc.). However, a variety of protrusion shapes may be used without departing from the scope of this disclosure.

<FIG> shows a cross section of an additional insulated canister assembly <NUM>, comprising a lid <NUM> removably coupled to a container body <NUM>. Container body <NUM> is shown as a double-walled container. Container body <NUM> includes outer wall <NUM> and inner wall <NUM>. Outer wall <NUM> and inner wall <NUM> may be coupled together at top <NUM>. A vacuum gap <NUM> may separate outer wall <NUM> and inner wall <NUM>, insulating central cavity <NUM> from the external environment when lid <NUM> is in place.

Lid <NUM> includes vacuum insert <NUM> and mating sleeve <NUM>. Mating sleeve <NUM> may function to partially encompass vacuum insert <NUM> and to enable lid <NUM> to mate with and form a seal with container body <NUM> (e.g., via a threading engagement). Vacuum insert <NUM> may be fabricated from stainless steel, from the same material as container body <NUM>, and/or from any other suitable material.

Mating sleeve <NUM> may be coupled to a top <NUM> that includes handle <NUM>. Handle <NUM> may be in the form of a bale arch that is configured to pivot away from the top of lid <NUM>. Lid <NUM> may include an upper seal <NUM> and a lower seal <NUM>. In this example, lower seal <NUM> may be considered a primary seal, while upper seal <NUM> may be considered a secondary seal. Upper seal <NUM> is depicted as an O-Ring that extends around mating sleeve <NUM>. Lower seal <NUM> is included in gasket <NUM>. Upper seal <NUM> may act, in addition to providing a seal, to center lid <NUM> on top <NUM>. Upper seal <NUM> may also provide feedback to a user as to when lid <NUM> is fully engaged with container body <NUM> (e.g., by increasing rotational friction), thereby decreasing the likelihood the user will over tighten lid <NUM>.

To address the aforementioned vacuum and friction issues, lid <NUM> includes gasket <NUM> that stretches across the base of lid <NUM> covering diaphragm chamber <NUM>. Diaphragm chamber <NUM> is shown as being coupled to an exterior of insulated canister assembly <NUM> via air channels <NUM>. As material within central cavity <NUM> cools, a vacuum may develop within central cavity <NUM>. The vacuum force within central cavity <NUM> of container body <NUM> may cause gasket <NUM> to flex towards central cavity <NUM>. Flexing of gasket <NUM> may in turn inflate diaphragm chamber <NUM> by drawing external air through air channels <NUM> and around mating threads <NUM>.

Diaphragm chamber <NUM> may thus expand to fill a portion of the space within central cavity <NUM>, thus creating a reduced volume and maintaining the internal pressure within central cavity <NUM>. This reduces the development of vacuum (and/or prevents a substantial increase of an existing vacuum condition), making canister assembly <NUM> easier to open. This approach thus accomplishes vacuum mitigation while maintaining central cavity <NUM> sealed from the outside, leveraging the flexing of gasket <NUM> to perform the ventilation function by effectively drawing air into central cavity <NUM> without actually exposing central cavity <NUM> to external air. As will be described further herein, elements of lid <NUM> also reduce friction between lid <NUM> and container body <NUM> by decoupling the sealing mechanism from the rotation of the mating threads <NUM>. Additional views of lid <NUM> are shown in <FIG> (perspective view) and <FIG> (cross-sectional view). Additional components such as coupling ring <NUM> and gasket tab <NUM> are indicated and discussed in more detail with regard to <FIG>, and <FIG>.

<FIG> shows an exploded view <NUM> of canister assembly <NUM>, including outer wall <NUM>, inner wall <NUM>, top <NUM>, handle <NUM>, vacuum insert <NUM>, upper seal <NUM>, mating sleeve <NUM>, gasket <NUM>, and coupling ring <NUM>. Coupling ring <NUM> is coupled to both gasket <NUM> and mating sleeve <NUM>. <FIG> shows an exploded view of lid <NUM>, including mating sleeve <NUM>, gasket <NUM>, and coupling ring <NUM>. Gasket <NUM> is fixed in position relative to coupling ring <NUM>. However, coupling ring <NUM> is configured to rotate freely around mating sleeve <NUM>. For example, both coupling ring <NUM> and mating sleeve <NUM> may be polycarbonate, and thus spin smoothly around each other, while coupling ring <NUM> and gasket <NUM> remain essentially stationary relative to one another.

As shown in <FIG>, mating sleeve <NUM> includes quarter-turn mating threads <NUM> to couple to the mating protrusions <NUM> of inner wall <NUM>. In this way, the upper portion of each thread is engaged when lid <NUM> is in place. The lower portion of mating threads <NUM> thus drives the mating sleeve off from mating protrusions <NUM>.

Because coupling ring <NUM> and gasket <NUM> rotate freely from mating sleeve <NUM>, gasket <NUM> does not rotate relative to inner wall <NUM> when lid <NUM> is being removed. Rather, mating threads <NUM> convert rotational force to axial force, effectively lifting gasket <NUM> out of container body <NUM> without gasket <NUM> swiping rotationally along inner wall <NUM>, and thus mitigating those frictional forces. Rather, gasket <NUM> moves up and down as mating threads <NUM> engage and disengage mating protrusions <NUM>.

<FIG> shows a close-up view of coupling ring <NUM>. As shown, coupling ring <NUM> is a split-ring, generating an air channel <NUM> which goes behind gasket <NUM>. The elastic nature of gasket <NUM> maintains coupling ring <NUM> in place. Coupling ring <NUM> may be flexible enough to allow a user to remove and replace the coupling ring for cleaning purposes, etc. As gasket <NUM> and coupling ring <NUM> rotate freely around mating sleeve <NUM>, they may be challenging to remove for cleaning. As such, a gasket tab <NUM> may be included to increase the ease of removing these components.

The split-ring allows air to enter the air channels <NUM> on the cap-side of diaphragm chamber <NUM>. These channels are thus exposed and active even when the cap is fully screwed on, while allowing gasket <NUM> to maintain a quality seal with inner wall <NUM>. <FIG> show a cross section of mating sleeve <NUM>, indicating air channels <NUM>. Air channels <NUM> traverse the base of the molded portion of mating sleeve <NUM>. However, other air channel pathways through lid <NUM> have been considered.

To facilitate air entry into air channels <NUM>, mating sleeve <NUM> may further include O-ring channels <NUM> which allow outside air to traverse upper seal <NUM>. Examples are shown in <FIG>. Thus, the development of a vacuum in central cavity <NUM> draws a force on gasket <NUM>, reducing pressure in diaphragm chamber <NUM>. The negative pressure in diaphragm chamber <NUM> is thus back-filled with external air, which enters canister assembly <NUM> via o-ring channels <NUM>, traverses gaps between mating protrusions <NUM>, and enters air channels <NUM> via the air channel <NUM> created by the split in coupling ring <NUM>. Lid <NUM> may then be removed without excessive vacuum or frictional forces.

Claim 1:
A lid (<NUM>) for an insulated container (<NUM>), comprising:
a flexible gasket, the flexible gasket (<NUM>) positioned so that when the lid (<NUM>) is fully engaged with the insulated container (<NUM>), the flexible gasket (<NUM>) forms a seal between the lid (<NUM>) and an inner wall (<NUM>) of the insulated container (<NUM>), the flexible gasket (<NUM>) further configured to expand into an interior compartment (<NUM>) of the insulated container (<NUM>) responsive to a vacuum developing in the interior compartment (<NUM>);
a diaphragm chamber (<NUM>) situated opposite the flexible gasket (<NUM>) from the interior compartment (<NUM>) when the lid (<NUM>) is fully engaged with the insulated container (<NUM>); and
one or more air channels (<NUM>) coupling the diaphragm chamber (<NUM>) to an exterior of the lid (<NUM>), wherein the diaphragm chamber (<NUM>) is located on an interior of a mating sleeve (<NUM>) configured to couple the lid (<NUM>) to the insulated container (<NUM>), characterized in that the mating sleeve (<NUM>) is coupled to the flexible gasket (<NUM>) via a coupling ring (<NUM>), wherein the coupling ring (<NUM>) is fixed in rotational position relative to the flexible gasket (<NUM>), and wherein the coupling ring (<NUM>) and the flexible gasket (<NUM>) rotate freely relative to the mating sleeve (<NUM>).