Patent Description:
A cap may be used to seal an opening of a pressurized container. When the container is highly pressurized, it will be nearly impossible to remove the cap without a leverage enhancing tool until the pressure of the container is equalized with the ambient atmosphere. Further, if a cap is removed from an opening while the container is pressurized, the pressure acting on the cap can cause the cap to explosively separate from the container. In addition, the pressurized fluid within the container may escape therefrom at a high temperature and/or velocity. Accordingly, accessing the interior of a container while the container is pressurized can result in potential injury to the operator or damage to an article surrounding the container. Containers with caps are disclosed in <CIT>, <CIT> and <CIT>.

According to one aspect, a container assembly is provided as defined by claim <NUM>.

In addition to one or more of the features described above, in embodiments the pressure relief valve is mounted to the housing at a position adjacent to the opening.

In further embodiments an axis of the pressure relief valve is oriented at an angle to an axis of the opening.

In further embodiments the axis of the pressure relief valve is perpendicular to the axis of the opening.

In further embodiments when the movable member is in the first position, the internal compartment is pressurized, and when the movable member is in the second position, the internal compartment is vented.

In further embodiments the engagement feature includes a groove extending about at least a portion of a periphery of the cap.

In further embodiments the engagement feature has a similar size and shape to a portion of the movable member with which the engagement feature cooperates.

In further embodiments the cap further comprises at least one vent hole, the at least one vent hole being arranged in fluid communication with the engagement feature.

In further embodiments when the movable member is in the first position, rotational movement of the cap relative to the opening is restricted.

In further embodiments the pressure relief valve further comprises a valve body having a first end and a second end, the first end being arranged adjacent to the cap, wherein the movable member extends through the first end in both the first position and the second position.

In further embodiments the engagement feature is located at a pressurized portion of the cap.

In further embodiments the engagement feature is located at a non-pressurized portion of the cap.

According to another aspect, a method of removing a cap from a container is provided as defined by claim <NUM>.

In further embodiments equalizing the pressure within the container and the ambient pressure further comprises providing a fluid flow between the pressure relief valve and the container.

In further embodiments equalizing the pressure within the container and the ambient pressure further comprises venting fluid from the container through the pressure relief valve when the container is pressurized.

In further embodiments venting fluid from the container through the pressure relief valve when the container is pressurized further comprises venting fluid from the container through at least one vent hole formed in the cap, the at least one vent hole being arranged in fluid communication with an end of the pressure relief valve.

In further embodiments the at least one vent hole is formed at the engagement feature.

In further embodiments unlocking the cap relative to the container further comprises separating a movable member of the pressure relief valve from an engagement feature of the cap.

In further embodiments separating the cap from the container further comprises rotating the cap to threadably decouple the cap from the container.

In further embodiments separating the cap from the container further comprises rotating and axially translating the cap to decouple the cap from the container.

With reference now to <FIG>, an example of a container <NUM> suitable for retaining a medium under pressure is illustrated. As shown, the container <NUM> has a container body including a housing <NUM> that defines a generally hollow internal compartment <NUM>. At least one port or opening <NUM> is formed in the housing <NUM> and is arranged in fluid communication with the internal compartment <NUM>. The opening <NUM> may be selectively sealed to retain the contents within the internal compartment of the container <NUM>. In an embodiment, the container <NUM> is a holding tank associated with a potable water system or waste water system of an aircraft. The holding tank <NUM> may be pressurized at any time when the aircraft is operational, including when the aircraft is on the ground. During normal operation, the pressure acting on a holding tank <NUM> of a potable water system is a positive pressure. However, in other applications, the holding tank <NUM> may experience a positive pressure or negative pressure during different operating conditions. Accordingly, any container <NUM> suitable for use in a pressurized application, including both positive pressure and negative pressure applications, are also within the scope of the invention as defined by the claims.

An example of an assembly <NUM> suitable to selectively close an opening, such as opening <NUM>, of the container <NUM> is illustrated in more detail in <FIG> and <NUM>-<NUM>. In the illustrated, non-limiting embodiment, the assembly <NUM> includes a cap <NUM> having an axially extending body <NUM>. As shown, all or at least a portion of the axial body <NUM> of the cap <NUM> is receivable within the opening <NUM>.

In the illustrated, non-limiting embodiment, the cap <NUM> further includes a radially outwardly extending flange <NUM> that, for example, has a diameter greater than the inner diameter of the opening <NUM> and, in some embodiments, is greater than or equal to an outer diameter of the housing <NUM> adjacent to the opening <NUM>. Although the flange <NUM> is shown as being located at an end of the body <NUM>, embodiments where the flange <NUM> is arranged at a central portion of the body <NUM> are also contemplated herein. In embodiments where the cap is removed by hand, the flange <NUM> may provide an area for a user to easily grasp and rotate the cap <NUM>. As shown, the flange <NUM> may be positionable adjacent to or in contact with an upper surface <NUM> of the housing <NUM> surrounding the opening <NUM> when the body <NUM> is received within the opening <NUM>. However, in other embodiments, the flange may be offset from the surface <NUM> when the body <NUM> is fully seated within the opening <NUM>. Further, embodiments where the cap <NUM> does not include a flange <NUM> are also contemplated herein.

The cap <NUM> is removably connectable to the housing <NUM> to close and seal the opening <NUM>. In an embodiment, best shown in <FIG> and <FIG>, a plurality of first threads <NUM> is formed at the inner surface <NUM> of the housing <NUM> and a plurality of second threads <NUM> is formed about an outer periphery of at least a portion of the body <NUM>. Accordingly, during installation of the cap <NUM> within the opening <NUM>, the cap <NUM> is rotated to threadably couple to the housing <NUM> of the container <NUM>. One or more parameters of the threads <NUM>, <NUM> may be selected such that the engagement between the first threads <NUM> and the second threads <NUM> is sufficient to maintain the cap <NUM> in position within the opening <NUM>, even when the container <NUM> is positively or negatively pressurized.

With reference now to <FIG>, a cap <NUM> and housing <NUM> connectable via another coupling mechanism is illustrated. As shown, the cap <NUM> is retained within the opening <NUM> of the housing <NUM> via a bayonet connection. At least one receiving groove <NUM> is formed within the inner surface <NUM> of the housing <NUM> within the opening <NUM>. The at least one receiving groove <NUM> has an axial component 44a and a circumferential component 44b. In the illustrated, non-limiting embodiment, the at least one receiving groove <NUM> is L-shaped. A locking feature <NUM> of the cap <NUM>, such as a pin for example, is receivable within the one or more receiving grooves <NUM>. In an embodiment, the pin <NUM> extends radially outwardly from an exterior surface of the axial body <NUM>.

To install the cap <NUM> within the opening <NUM>, each pin <NUM> is aligned with and slidably received within the axial component 44a of the receiving groove <NUM>. The cap <NUM> is then rotated, thereby moving the pin <NUM> through the circumferential portion 44b of the receiving groove <NUM> to a position where axial movement of the cap <NUM> is restricted by one or more surfaces of the housing <NUM>. In an embodiment, the cap <NUM> includes a boss <NUM> that may be used to rotate the cap <NUM> via a wrench or other suitable tool. The boss <NUM> may be arranged at a first end of the axial body <NUM>, and may be arranged external to, or within the opening <NUM> when the cap <NUM> is mounted within the opening <NUM>.

It should be understood that the threaded connection and the bayonet connection described herein are intended as an example only and that embodiments where the cap <NUM> is removably connected to the housing <NUM> via another suitable coupling mechanism are also within the scope of the disclosure. Further, embodiments where the body <NUM> of the cap <NUM> is receivable about the exterior of the housing <NUM>, rather than within the opening <NUM>, to close and seal the opening <NUM> are also contemplated herein.

The threaded connection and the bayonet connections illustrated and described herein are intended to take the primary pressure load. The engagement between the cap <NUM> and the housing <NUM> may be sufficient to form a seal therebetween. However, in other embodiments, another component may be used to form the seal. In an embodiment, an O-ring, gasket, or other flexible seal wraps about the periphery of the body <NUM> such that when the cap <NUM> is installed relative to the opening <NUM>, the seal is configured to directly contact an adjacent surface of the housing <NUM>, such as inner surface <NUM> for example, to form an air-tight seal between the body <NUM> and the housing <NUM>. In other embodiments, cap <NUM> and housing <NUM> may have matching smooth surfaces to engage and seal without the addition of another part or material.

A pressure relief valve <NUM> is associated with the cap <NUM> to further restrict movement of the cap <NUM> relative to the opening <NUM> when the container <NUM> is pressurized. In the illustrated, non-limiting embodiment, the pressure relief valve <NUM> is mounted to the housing <NUM> adjacent to the cap <NUM>. The pressure relief valve <NUM> may be permanently affixed to the housing <NUM>, or alternatively, may be removably coupled therein. Although the pressure relief valve <NUM> is shown as being threadably coupled to the housing <NUM>, embodiments where the pressure relief valve <NUM> is integral with the housing and/or embodiments where the pressure relief valve is mounted to the cap <NUM> via another suitable mechanism are also contemplated herein. Further, as shown, the axis of the pressure relief valve <NUM>, as defined by movement of the movable member (to be described in more detail below), is oriented generally perpendicular to the axis of the opening <NUM> and the cap <NUM>. However, in other embodiments, the axis of the pressure relief valve <NUM> may be oriented at another angle to the axis of the cap <NUM>.

An example of a pressure relief valve <NUM> is shown in more detail in <FIG>. As shown, the pressure relief valve <NUM> includes a valve body <NUM> having a first end <NUM> and a second end <NUM>, and an internal chamber <NUM> extending between the first end <NUM> and the second end <NUM>. The first end <NUM> and the second end <NUM> may each have an opening <NUM>, <NUM> formed therein, and a valve cap <NUM> may be connected to the second end <NUM> of the valve body <NUM> to close and seal the opening <NUM> at the second end <NUM>. The valve body <NUM> additionally includes at least one vent hole <NUM> for venting pressure through the pressure relief valve <NUM> to the atmosphere. In the illustrated, non-limiting embodiment, the pressure relief valve <NUM> includes two vent holes <NUM> that are evenly spaced about the periphery of the valve body <NUM>. However, it should be understood that a pressure relief valve <NUM> having any suitable configuration of vent holes <NUM> is within the scope of the disclosure. Further, it should be understood that the total number, the size, and the position of the vent holes <NUM> may be selected based on the application and the total amount of fluid to be released through the valve and a desired time to release the pressure.

A movable member <NUM>, also referred to as a valve member, is mounted within the chamber <NUM>. The movable member <NUM> includes an elongated valve stem <NUM> and a disc or collar <NUM> mounted to a portion of the valve stem <NUM>. In the illustrated, non-limiting embodiment, the disc <NUM> is arranged at a central portion of the valve stem <NUM>. However, the disc <NUM> may be located at another portion of the valve stem <NUM>, such as at an end thereof for example. A portion of the valve stem <NUM> is configured to extend through the valve cap <NUM>, to the exterior of the valve body <NUM>. As shown, a handle or lever <NUM> (see <FIG>) for selectively operating or releasing the pressure relief valve <NUM> is connected to the external portion of the valve stem <NUM>.

The movable member <NUM> is configured to translate between a first position in which the pressure relief valve <NUM> is normally closed, and a second position in which the pressure relief valve <NUM> is open. In the first position, a portion of the movable member <NUM> is arranged in position to substantially seal the opening <NUM> of the first end <NUM> of the valve body <NUM>. When in the first position, the disc <NUM> itself may be used to seal the opening <NUM>, or alternatively, a seal <NUM>, such as an O-ring for example, mounted to the valve stem <NUM> and/or the disc <NUM> may seal the opening <NUM>. In the second position, the disc <NUM> and/or seal <NUM> are spaced apart from the opening <NUM> by a distance. As a result, fluid is configured to flow through the opening <NUM> at the first end <NUM>, into the chamber <NUM>, and out to the ambient atmosphere via the one or more vent holes <NUM>. It should be understood that for embodiments where the container is negatively pressurized (vacuum), when the valve <NUM> is opened, air will flow in the opposite direction, into the interior of the container <NUM> to equalize the pressure within the container <NUM> with the pressure of the ambient atmosphere.

A biasing member <NUM> (best shown in <FIG>), such as a spring for example, is located within the chamber <NUM> and is operably coupled to the movable member <NUM>. In an embodiment, the biasing member <NUM> is a coil spring mounted concentrically about the valve stem <NUM>, extending between a surface of the valve cap <NUM> and a surface of the disc <NUM>. A biasing force of the biasing member <NUM> is configured to bias the movable member <NUM> toward the opening <NUM> at the first end <NUM>, thereby causing the pressure relief valve <NUM> to be normally closed.

Operation of the lever <NUM> is configured to transform the movable member <NUM> between the first position and the second position. In the illustrated, non-limiting embodiment, the lever <NUM> includes a cam surface <NUM> that is configured to engage an adjacent surface, such as of the valve cap <NUM> for example. Accordingly, as the lever <NUM> rotates about an axis from a first configuration to a second configuration, the camming action causes the movable member <NUM> to translate axially in a direction opposite the bias of the biasing member <NUM>. The cam surface <NUM> of the lever <NUM> may be configured to hold the lever <NUM> in the second configuration, thereby holding the valve open. However, in other embodiments, other mechanisms may be used to hold the movable member <NUM> in the translated position such that the valve remains open. Further, as the lever <NUM> is rotated from the second configuration toward the first configuration, and the force opposing the biasing member <NUM> is removed, the movable member <NUM> is biased back to the first position. It should be understood that the pressure relief valve <NUM> illustrated and described herein is intended as an example only and that a pressure relief valve <NUM> having any suitable configuration is within the scope of the disclosure.

With continued reference to <FIG>, <FIG>, and <FIG>, in the illustrated, non-limiting embodiments, when the pressure relief valve <NUM> is in the sealed, first normal position, the movable member <NUM> of the pressure relief valve <NUM> extends through the first end <NUM> of the valve body <NUM> and is engaged with a portion of the cap <NUM>. Accordingly, the movable member <NUM> "locks" the cap <NUM> in place within the opening <NUM> by restricting axial movement thereof. To unlock the cap, the movable member <NUM> is moved to the second position, such that the movable member <NUM> and the cap <NUM> are disengaged. Although the movable member <NUM> is illustrated as being engaged with the body <NUM> of the cap <NUM>, it should be understood that embodiments where the movable member is engaged with the flange <NUM> of the cap <NUM> are also contemplated herein.

As shown, an engagement feature <NUM>, such as a groove for example, is formed in a surface of the cap <NUM> and the distal end <NUM> of the movable member <NUM> is receivable therein. The engagement feature <NUM> may be located at either a pressurized portion of the cap <NUM> or at a non-pressurized portion of the cap <NUM>. The engagement feature <NUM> may include one or more of an annular groove that extends about the entire periphery of the body <NUM>, a groove that wraps about only a portion of the outer periphery of the body, an axial groove (see <FIG> and <FIG>), and a groove generally complementary in size and shape to the distal end <NUM> of the movable member <NUM>. In embodiments where the engagement feature <NUM> is an annular groove or a groove that wraps about a portion of the outer periphery, the cap <NUM> is at least partially rotatable about its axis when the distal end <NUM> of the movable member <NUM> is received within the engagement feature <NUM>. In embodiments where the engagement feature <NUM> is an axial groove, the cap <NUM> may be partially translatable along the cap's axis of rotation. However, in embodiments where the engagement feature <NUM> is a single groove complementary to the distal end <NUM> of the movable member <NUM>, both axial and rotational movement of the cap <NUM> is prevented. Although the engagement feature <NUM> is illustrated and described as a groove formed in the surface of the body <NUM>, it should be understood that any configuration where the distal end <NUM> of the movable member <NUM> cooperates with at least one of an engagement feature <NUM> of the cap <NUM> and the features connecting the cap <NUM> to the opening <NUM>, such as threads <NUM>/<NUM> or bayonet connection <NUM>/<NUM>, to restrict rotational and/or axial movement of the cap <NUM> is within the scope of the disclosure.

One or more vent holes <NUM> arranged in fluid communication with the interior of the container <NUM> are formed in the body <NUM> of the cap <NUM>. In an embodiment, at least one vent hole <NUM> is axially aligned with the one or more engagement features <NUM> formed therein. Accordingly, when the pressure relief valve <NUM> is opened by moving the movable member <NUM> to the second position, fluid, such as pressurized air for example, is configured to flow from the internal compartment <NUM> of the container <NUM> to the engagement feature <NUM> via the at least one vent hole <NUM> and from the engagement feature <NUM> into the open first end <NUM> of the pressure relief valve <NUM> for release to the ambient atmosphere as previously described.

By restricting movement of the cap <NUM> using the movable member <NUM> of a pressure relief valve <NUM>, the pressure relief valve <NUM> must be opened and pressure must be released from the container <NUM> prior to removing the cap <NUM> therefrom. Further, such an assembly provides a fail-safe measure without adding excess components or weight to the system.

Claim 1:
A container assembly comprising:
a container body having a housing (<NUM>) defining an internal compartment (<NUM>) and an opening (<NUM>) connected to the internal compartment;
a cap (<NUM>) mounted to the housing about the opening, characterized by the cap having an axially extending body (<NUM>) receivable within the opening (<NUM>) and an engagement feature (<NUM>) formed within the axially extending body; and
a pressure relief valve (<NUM>) mounted to the housing and operably coupled with the internal compartment to vent fluid from the internal compartment, the pressure relief valve having a movable member (<NUM>) movable between a first position and a second position, wherein when the movable member is in the first position, the movable member is configured to cooperate with the engagement feature to restrict movement of the cap relative to the opening.