Patent Description:
Luminaires with automated and remotely controllable functionality (which may be referred to as automated luminaires) are well known in the entertainment and architectural lighting markets. Such products are commonly used in theatres, television studios, concerts, theme parks, night clubs, and other venues. A typical automated luminaire provides control from a remote location of the pan and tilt functions of the luminaire allowing an operator to control the direction the luminaire is pointing and thus the position of the light beam on the stage or in the studio. Many automated luminaires additionally or alternatively provide control from the remote location of other parameters such as intensity, focus, zoom, beam size, beam shape, and/or beam pattern of light beam(s) emitted from the luminaire. Such automated luminaire products are often used outdoors in, for example, theme parks or concerts. Maintaining a dry, controlled physical environment inside an automated luminaire is important for the continuing operation of the unit. Prior art automated luminaires are known from <CIT>, <CIT> and <CIT>.

For a more complete understanding of this disclosure, reference is now made to the following brief description, taken in conjunction with the accompanying drawings in which like reference numerals indicate like features.

In a first embodiment, a luminaire includes a first enclosure, a second enclosure, a pipe coupled to the first and second enclosures, and a chamber coupled to the first enclosure. The first enclosure includes one or more luminaire components that are configured to modify and emit a light beam. The first enclosure also includes first and second openings and is otherwise sealed from external air. The second enclosure includes electronic circuits electrically coupled to the luminaire components of the first enclosure. The second enclosure also includes a third opening and is otherwise sealed from the external air. The first enclosure is rotatably mounted to the second enclosure. The pipe is coupled at a first end by a rotatable sealed air coupling to the first enclosure at the first opening and at a second end by a fixed sealed air coupling to the second enclosure at the third opening. The pipe is otherwise sealed from the external air. The chamber includes a drying agent, has fourth and fifth openings, and is otherwise sealed from the external air. The chamber is coupled at the fourth opening by a rotatable sealed air coupling to the first enclosure at the second opening. The fifth opening has a membrane completely covering the fifth opening, the membrane comprising a material configured to allow air to pass through the material while reducing the passage of water droplets in the air.

The luminaire may further include a third enclosure that is rotatably mounted to the first enclosure and to the second enclosure, whereby the first enclosure is rotatably mounted to the second enclosure by the third enclosure. The third enclosure includes a motor that is electrically coupled to the electronic circuits of the second enclosure. The motor rotates the first enclosure relative to the third enclosure. The third enclosure includes sixth and seventh openings and is otherwise sealed from the external air. The sixth opening is coupled to the pipe at the second end by the sealed air coupling. The seventh opening is coupled by a rotatable sealed air coupling to the second enclosure at the third opening.

Preferred embodiments are illustrated in the figures, like numerals being used to refer to like and corresponding parts of the various drawings.

If a luminaire (or fixture) is used outdoors or in another area where it is subject to rain, weather, or high humidity it is important to protect any luminaire mechanisms and optical systems from the effects of moisture and humidity. Some fixtures may have sealed housings or semi-sealed housings with pressure equalization. Such fixtures may suffer from effects caused by the thermal operating cycle, as follows. When an automated luminaire is turned on, internal systems such as light sources, electronics, power supplies, and motors generate heat and cause the temperature inside the fixture to rise. Such a rise in temperature produces a corresponding increase in the air pressure within the luminaire.

In some fixtures, this pressure is contained within the luminaire using hermetic seals. The load on such a hermetic seal from such a pressure increase within the luminaire can be significant and the repair and maintenance of the seals may be expensive and/or difficult. A failure in such seals may lead to water ingress into the luminaire, which may lead to damage or degradation of the luminaire mechanisms and/or optical systems.

In other fixtures, the fixture is sealed, but the pressure is allowed to escape through pressure relief valves. However, when such a fixture is powered off and cools down, its internal pressure drops relative to atmospheric pressure outside the fixture and external air (or outside air) and moisture may be drawn back into the luminaire through the seals, the pressure relief valve, or other paths. This too can lead to water ingress to the luminaire or condensation within the luminaire and damage or degradation of the luminaire mechanisms and/or optical systems.

Luminaires according to the disclosure are sealed, but also are vented to the outside air through a system that removes excess humidity from incoming air and reduces condensation within the luminaire. This has the advantage of reducing water ingress to the luminaire and condensation within the luminaire, as well as reducing damage or degradation of the luminaire mechanisms and/or optical systems.

Luminaires according to the disclosure are also segmented into enclosures that are sealed and are coupled to each other to allow passage of air between the enclosures. The connected enclosures are vented to the outside air through each other to a single water and humidity reducing system. In such embodiments, the enclosures are coupled by air passages that are rotatably coupled to the enclosures, giving the advantage of allowing one or more of the enclosures to rotate relative to each other while reducing water ingress to the luminaire and condensation within the luminaire. Optical, mechanical, and electrical components of the luminaire may be located in various ones of the enclosures as appropriate to the design and functioning of the luminaire.

<FIG> presents a schematic view of a luminaire system <NUM> according to the disclosure. The luminaire system <NUM> includes a plurality of luminaires <NUM> according to the disclosure. The luminaires <NUM> each contains on-board a light source, one or more of color changing systems, light modulation devices, and pan and/or tilt systems to control an orientation of a head of the luminaire <NUM>. Mechanical drive systems to control parameters of the luminaire <NUM> include motors or other suitable actuators coupled to a control system, as described in more detail with reference to <FIG>, which is configured to control the motors or other actuators.

In addition to being connected to mains power either directly or through a power distribution system, the control system of each luminaire <NUM> is connected in series or in parallel by a wired data link <NUM> to one or more control desks <NUM>. Upon actuation by an operator, the control desk <NUM> sends control signals (such as commands) via the data link <NUM>, where the control signals are received by the control system of one or more of the luminaires <NUM>. The control systems of the one or more of the luminaires <NUM> that receive the control signals may respond by changing one or more of the parameters of the receiving luminaires <NUM>. The control signals are sent by the control desk <NUM> to the luminaires <NUM> using DMX-<NUM>, Art-Net, ACN (Architecture for Control Networks), Streaming ACN, or other suitable communication protocol.

The luminaire head of the luminaire <NUM> comprises an optical system comprising one or more luminaire mechanisms, each of which includes one or more optical devices such as gobo wheels, effects wheels, and color mixing (or other color changing) systems, as well as prism, iris, shutter, and lens movement systems. The term luminaire mechanisms further includes a pan and tilt mechanism configured to move the luminaire head relative to a fixed portion of the luminaire <NUM>. Some or all of the luminaire mechanisms may include stepper motors or other rotating actuators to cause movement of their associated optical device(s).

<FIG> presents a first view of a luminaire <NUM> comprising a luminaire humidity and pressure control system according to the disclosure. <FIG> shows the luminaire <NUM> with some components removed so that the humidity and pressure control system is more easily seen and described. The luminaire <NUM> may comprise a number of separate enclosures that can be protected by the humidity and pressure control system. The luminaire <NUM> includes a base enclosure <NUM>, a motor enclosure <NUM>, and a head enclosure <NUM>. The base enclosure <NUM> is a portion of the luminaire that is typically fixedly attached to or rests on a supporting structure and remains stationary. The base enclosure <NUM> may include power supplies, interface electronics, and other control equipment. The motor enclosure <NUM> may include the motors and associated electronics that control pan and/or tilt motion of the luminaire head. The head enclosure <NUM> may include luminaire components such as optical devices and associated motors, as well as circuits and other control electronics. A light source <NUM> may be located within the head enclosure <NUM> or may be external to, but optically coupled with, the head enclosure <NUM>, as described in more detail with reference to <FIG>. The light source <NUM> and the luminaire components produce and modify a light beam that is emitted from the head enclosure <NUM>. The head enclosure <NUM> moves in a tilt direction relative to the motor enclosure <NUM>, the motor enclosure <NUM> moves in a pan direction relative to the base enclosure <NUM>. Thus, the head enclosure <NUM> is rotatably mounted to the base enclosure <NUM> by the motor enclosure <NUM>.

Although the luminaire <NUM> includes three enclosures, in other embodiments any number of enclosures may be included. For example, a light bar or cyclorama luminaire may have only the head enclosure <NUM> mounted for tilt motion relative to the base enclosure <NUM>. The motors and associated electronics that control tilt motion of such a luminaire may be located in either or both of the base enclosure <NUM> and/or the head enclosure <NUM>. Still other embodiments may include only a single enclosure or more than three enclosures. The ability to increase the number of enclosures in a luminaire according to the disclosure provides the advantage of increasing the number of luminaire components that may be protected from damage or degradation caused by water ingress and/or condensation, while also allowing the additional components to rotate relative to each other. It is to be understood that when the phrase `connected enclosures' is used in this specification, it means one or more enclosures.

All three enclosures <NUM>, <NUM>, and <NUM> are sealed such that external air does not pass through the seals. However, the enclosures <NUM>, <NUM>, and <NUM> are connected together and vented through drying tubes <NUM> and <NUM> that allow air to flow into and out of the enclosures, such that an internal air pressure in the enclosures <NUM>, <NUM>, and <NUM> never rises significantly above or below an external atmospheric pressure, thereby reducing pressure on the seals of the enclosures. In the luminaire <NUM>, the base enclosure <NUM> is vented to the motor enclosure <NUM> through a pipe <NUM> that couples an opening in the base enclosure <NUM> to an opening in the motor enclosure <NUM>.

The pipe <NUM> provides a rotatable sealed air coupling between the base enclosure <NUM> to the motor enclosure <NUM>. The coupling is an air coupling because it allows passage of air from the base enclosure <NUM> to the motor enclosure <NUM>. The coupling is a sealed air coupling because it is sealed from the external air. The coupling is a rotatable sealed air coupling because it comprises rotating flanges, gaskets, seals, and/or other elements configured to allow the base enclosure <NUM> and the motor enclosure <NUM> to rotate relative to each other while still allowing the passage of air. A sealed air coupling that does not allow the pipe <NUM> to rotate relative to the base enclosure <NUM> or the motor enclosure <NUM> may be referred to as a fixed sealed air coupling. The pipe <NUM> provides a rotatable sealed air coupling that is configured to pass air from the base enclosure <NUM> to the motor enclosure <NUM>, sealed from the external air, through the rotating pan system at the base of the motor enclosure <NUM> by which the motor enclosure <NUM> rotates relative to the base enclosure <NUM>.

In turn, the motor enclosure <NUM> is vented to the head enclosure <NUM> through a pipe <NUM>. The pipe <NUM> comprises a sealed air coupling at a first end <NUM> to an opening in the motor enclosure <NUM> and a rotating sealed air coupling at a second end <NUM> to an opening in the head enclosure <NUM>. The pipe <NUM> is configured to pass air from the motor enclosure <NUM> to the head enclosure <NUM> through the rotating tilt system on the side of the head enclosure <NUM>.

The three enclosures <NUM>, <NUM>, and <NUM> are thus connected together by pipes <NUM> and <NUM> to form a combined enclosure having pressure and humidity control. The combined enclosure is vented to the external air through a vent pipe <NUM> via an opening in the head enclosure <NUM>. The vent pipe <NUM> comprises a rotating sealed air coupling at a first end to the opening in the head enclosure <NUM>. The vent pipe <NUM> comprises a sealed air coupling at a second end to a drying tube (or chamber) <NUM>, which is sealed air coupled to a drying tube <NUM>. The drying tubes <NUM> and <NUM> include a drying agent such as silica gel or other suitable desiccant material. An exit opening of the drying tube <NUM> includes a membrane <NUM> that air couples the drying tube <NUM> to the surrounding atmosphere (the external air).

The membrane <NUM> may comprise a hydrophobic membrane material such as GORE-TEX (a registered trademark of W. Gore & Associates, Newark, Delaware) or other suitable material that allows air to pass through, but reduces or prevents the passage of water and/or moisture in the form of water droplets. Thus, the membrane <NUM> is configured to remove water droplets from incoming air and the drying agent of the drying tubes <NUM> and <NUM> is configured to remove water vapor (or humidity) from incoming air.

In operation, when the luminaire <NUM> is powered up, both the temperature and internal air pressure within the three enclosures <NUM>, <NUM>, and <NUM> rise. This increase in air pressure forces air out of the enclosures <NUM>, <NUM>, and <NUM> through the vent pipe <NUM> and drying tubes <NUM> and <NUM> before exiting the luminaire <NUM> at membrane <NUM>. When the luminaire <NUM> is powered down, both the temperature and the internal air pressure inside the enclosures <NUM>, <NUM>, and <NUM> drop and external air may be drawn back into the luminaire <NUM> through the membrane <NUM>, reducing or eliminating liquid water and/or moisture in the indrawn air. The indrawn air then passes through the drying tubes <NUM> and <NUM>. The drying tubes <NUM> and <NUM> will remove water vapor from the indrawn air, causing the air that enters the enclosures <NUM>, <NUM>, and <NUM> through vent pipe <NUM> to have a reduced humidity. This forcing of air out of and subsequent drawing of air back into the enclosures <NUM>, <NUM>, and <NUM> may be referred to as an `air cycle path' of the luminaire humidity and pressure control system of the disclosure.

Because the volume of air passing out of and into the enclosures <NUM>, <NUM>, and <NUM> through the drying tubes <NUM> and <NUM> is relatively small, the drying tubes <NUM> and <NUM> have a capacity to remove the humidity for multiple on/off cycles of the luminaire <NUM>. In some embodiments the drying tubes <NUM> and <NUM> contain enough drying agent to dehumidify <NUM> on/off cycles of the luminaire <NUM> before requiring regeneration or replacement of the drying agent by a service technician. The term 'regeneration' refers to a drying treatment that removes absorbed moisture from the drying agent, renewing or regenerating the capacity of the drying agent to continue absorbing moisture. The term 'life' of the drying agent may be used to refer to the time from a first use of the drying agent to the point where its reduced effectiveness as a desiccant requires regeneration or replacement by a service technician. Although the example shown uses two drying tubes <NUM> and <NUM>, in other embodiments one drying tube (or drying chamber) or more than two drying tubes may be included. Similarly, although some embodiments utilize silica gel as a drying agent, in other embodiments the drying tubes or chambers may additionally or alternatively include other drying agents.

In some embodiments, the hot dry air being forced out when the luminaire <NUM> is powered on will regenerate the drying agent in the drying tubes, extending the life of the drying agent. In further embodiments, this drying and regeneration process may be enhanced by using a heater (not shown in <FIG>) inside or around one or both of the drying tubes <NUM> and <NUM>.

In some embodiments, one or more of the enclosures <NUM>, <NUM>, and <NUM> may include one or more sensors that are configured to measure characteristics of the enclosure, where the characteristics are selected from, but not limited to, air pressure, air humidity, and/or air temperature. Data samples from such sensors may be collected by a control system of the luminaire <NUM> and information related to the collected data samples sent (or transmitted) to a user via one or more communication channels such as a display included in the luminaire <NUM>, the wired data link <NUM> using a protocol such as Remote Device Management (RDM), a web connection via the data link <NUM>, a cellular or WiFi wireless connection, or a near-field communication (NFC) or other wireless communication link. Such sending of the information has the advantage of allowing a user of the luminaire <NUM> to obtain the information without opening the luminaire <NUM> or to receive the information at a remote location, rather than being required to access the luminaire <NUM> to obtain the information. In some embodiments, a plurality of such data samples may be stored in a service log of the luminaire <NUM> and the contents of the log sent via one or more of the above channels to the user, a service technician, or the manufacturer. Such of a plurality of data samples in a service log has the advantage of giving a historical record of the sensed characteristics within the luminaire. In some such embodiments, the service log may also include a timestamp associated with one or more of the data samples, the timestamp indicating a time at which the data sample was collected and allowing the user, a service technician, or the manufacturer to identify a time at which a data sample of interest was collected.

Additionally, in some such embodiments, the control system of the luminaire <NUM> may determine, based on data from such sensors, whether the sealed enclosures have been effectively sealed (or re-sealed after maintenance). For example, when the luminaire <NUM> is powered on if an air pressure sensor indicates that the air pressure inside one or more of the enclosures <NUM>, <NUM>, and <NUM> is not rising, while at the same time the temperature sensor indicates that the temperature in the enclosure is rising, then this data may be interpreted by the control system as an indication that one or more of the enclosures <NUM>, <NUM>, and <NUM> are incompletely sealed to the external air. Such a determination provides the advantage of (i) enabling a service technician to determine whether the enclosure(s) have been effectively re-sealed after maintenance, prior to returning the luminaire <NUM> to service, and/or (ii) enabling a user of the luminaire <NUM> to determine remotely whether the seals have failed in an enclosure that was previously effectively sealed.

<FIG> presents an overview of the luminaire <NUM> of <FIG> in a fully assembled state. The sealed enclosures and associated connecting pipes are hidden in <FIG> by external housings or cowls.

<FIG> presents a schematic view of a luminaire humidity and pressure control system <NUM> according to the disclosure. <FIG> is a simplified diagrammatic view of the luminaire humidity and pressure control system <NUM> of the luminaire <NUM> described with reference to <FIG>. A base enclosure <NUM> is vented through a pipe <NUM> that connects the base enclosure <NUM> to a motor enclosure <NUM>. In turn, the motor enclosure <NUM> is vented through a pipe <NUM> (having ends <NUM> and <NUM>) that connects the motor enclosure <NUM> to a head enclosure <NUM>. The three enclosures <NUM>, <NUM>, and <NUM> are thus connected together with tubing that creates a combined enclosure for pressure and humidity control. The head enclosure <NUM> is vented through a pipe <NUM>, also venting the enclosures <NUM> and <NUM>. The pipe <NUM> enters a drying tube <NUM>, which includes a drying agent such as silica gel. Finally, at an exit of the drying tube <NUM>, a membrane <NUM> connects the system to the external atmosphere. Membrane <NUM> may be made of a micro-filter material such as GORE-TEX which allows air to pass through, but reduces or prevents the passage of water or moisture. In the embodiment shown in <FIG>, a heater <NUM> is mounted around (or thermally coupled to) the drying tube <NUM> and may be controlled by a control system of the luminaire <NUM> to heat the drying agent during the hot-air venting phase of the cycle and/or other desired periods, providing the advantage of regenerating the drying agent and extending its life. In other embodiments, the heater <NUM> may be mounted inside the drying tube <NUM>. Still other embodiments may not include the heater <NUM>.

The head enclosure <NUM> includes a sensor <NUM> that measures one or more parameters such as air pressure, air humidity, or air temperature. In other embodiments, one or more of such sensors <NUM> may be included in the enclosures <NUM> and/or <NUM>. In some embodiments, a plurality of such sensors <NUM> may be included in one or more of the enclosures <NUM>, <NUM>, and <NUM>.

Data samples from such sensors may be collected by the control system of the luminaire <NUM>. The control circuit <NUM> is located in the base enclosure <NUM>. In other embodiments, a control circuit <NUM> may be additionally or alternatively located in the head enclosure <NUM>. In still other embodiments, a control circuit (not shown in <FIG>) may be located in the motor enclosure <NUM>. Such one or more control circuits may separately or cooperatively form the control system for the luminaire <NUM>. Information related to the collected data samples may be sent to a user by the control system via one or more communication channels as described above. As also described above, in various embodiments, the data samples may include a timestamp and may be stored and sent to the user, a service technician, or the manufacturer.

<FIG> further shows a light source <NUM> external to the head enclosure <NUM>. The light source <NUM> is optically and physically coupled to the head enclosure <NUM>, but separated and sealed from the head enclosure <NUM> by a transparent window and gasket <NUM>. Heat generated by the light source <NUM> may be significant, and such an arrangement provides the advantage of keeping heat emanating from the light source <NUM> external to the head enclosure <NUM> and helping to reduce the temperature rise and the air pressure rise within the head enclosure <NUM>. Such reductions have the advantage of lessening the volume of air that exits and re-enters the combined enclosure of the three enclosures <NUM>, <NUM>, and <NUM> during each on/off cycle, helping to increase the life of the drying agent in drying tube <NUM>.

<FIG> presents a second view of the luminaire <NUM> of <FIG>. The luminaire <NUM> includes drying boxes <NUM> in the base enclosure <NUM> and a drying box <NUM> in the head enclosure <NUM>. In various embodiments, zero or more drying boxes may be included in any enclosure of a luminaire humidity and pressure control system according to the disclosure.

The drying boxes <NUM> and <NUM> are not part of the air cycle path described with reference to <FIG>, which occurs when the luminaire <NUM> heats up and cools down. Instead the drying boxes <NUM> and <NUM> aid in initial assembly and subsequent maintenance. When the luminaire <NUM> is manufactured and the enclosures <NUM>, <NUM>, and <NUM> are first sealed, they will contain the air from the factory, which may be humid. The drying boxes <NUM> and <NUM> include a drying agent such as silica gel and a plurality of openings in the box that expose the drying agent to the air in the enclosure. Once the enclosure is sealed, such boxes will remove some of the initial humidity captured within the enclosure, even before the luminaire is powered. The drying boxes <NUM> and <NUM> may also help ensure that air in the enclosures remain dry during storage and shipping.

In some embodiments, the drying agent inside any of the drying boxes <NUM> and <NUM> and/or the drying tubes <NUM> and <NUM> changes color when it absorbs moisture. In some such embodiments, the drying boxes <NUM> and <NUM> and/or the drying tubes <NUM> and <NUM> are configured to allow such color-changing drying agent to be easily visible. In some such embodiments, the drying boxes <NUM> and <NUM> and/or the drying tubes <NUM> and <NUM> may be fabricated at least in part of a transparent or translucent material. In other such embodiments, the drying box or drying tube may have an easy to remove portion of the box or tube exposing the drying agent to view. In still other embodiments, one or more of the plurality of openings in the drying box may be sized to allow viewing of the drying agent through the opening. Such a drying agent and drying boxes or drying tubes provide the advantage of enabling a user or service technician to visually check whether the drying agent is ready for use or needs regeneration or replacement before sealing the enclosures <NUM>, <NUM>, and <NUM> of the luminaire <NUM>.

The inclusion of the drying boxes <NUM> and <NUM> provides the advantage of an extra, initial drying cycle, which may serve to extend the life of the drying agents in the drying tubes within the luminaire. The inclusion of the drying boxes <NUM> and <NUM> provides the advantage of allowing the luminaire <NUM> to be placed back into service more quickly, without requiring the use of external tools to dehumidify the sealed enclosure or to flush the humid air from the sealed enclosure with nitrogen or dehumidified air.

<FIG> presents a block diagram of a control system (or controller) <NUM> according to the disclosure. The control system <NUM> is suitable for use to control the systems of a luminaire comprising a luminaire humidity and pressure control system according to the disclosure. The control system <NUM> is also suitable for controlling the light source, optical devices, pan and/or tilt systems, and other control functions of the luminaires <NUM> and <NUM> as well as connecting and responding to and storing data read from sensors installed within the luminaires <NUM> and <NUM>.

The control system <NUM> includes a processor <NUM> electrically coupled to a memory <NUM>. The processor <NUM> is implemented by hardware and software. The processor <NUM> may be implemented as one or more Central Processing Unit (CPU) chips, cores (e.g., as a multi-core processor), field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and digital signal processors (DSPs).

The processor <NUM> is further electrically coupled to and in communication with a communication interface <NUM>. The communication interface <NUM> is coupled to, and configured to communicate via, the data link <NUM>. The processor <NUM> is also coupled via a control interface <NUM> to one or more sensors <NUM>, motors, actuators, controls, heater <NUM>, and/or other devices. The processor <NUM> is configured to receive control signals from the data link <NUM> via the communication interface <NUM> and, in response, to control systems and mechanisms of the luminaire <NUM> via the control interface <NUM>.

Via the control interface <NUM>, the processor <NUM> is further electrically coupled to and in communication with temperature, humidity, and/or pressure sensors such as the sensor <NUM>. The processor <NUM> is configured to receive control signals from the data link <NUM> via the communication interface <NUM> and, in response, measure, store, and transmit information related to data sampled from one or more of the sensors <NUM>.

The control system <NUM> is suitable for implementing processes, module control, optical device control, pan and tilt movement, parameter control, motor control, position sensor control, brake control, and other functionality as disclosed herein, which may be implemented as instructions stored in the memory <NUM> and executed by the processor <NUM>. The memory <NUM> comprises one or more disks and/or solid-state drives and may be used to store instructions and data that are read and written during program execution. The memory <NUM> may be volatile and/or non-volatile and may be read-only memory (ROM), random access memory (RAM), ternary content-addressable memory (TCAM), and/or static random-access memory (SRAM).

Claim 1:
A luminaire (<NUM>, <NUM>), comprising:
a first enclosure (<NUM>, <NUM>) comprising one or more luminaire components configured to modify and emit a light beam, the first enclosure including first and second openings and being otherwise sealed from external air;
a second enclosure (<NUM>, <NUM>) comprising electronic circuits electrically coupled to the luminaire components of the first enclosure, the second enclosure including a third opening and being otherwise sealed from the external air, wherein the first enclosure is rotatably mounted to the second enclosure;
a pipe (<NUM>, <NUM>) that is air coupled at a first end (<NUM>, <NUM>) by a first rotatable sealed air coupling to the first enclosure at the first opening and at a second end (<NUM>, <NUM>) by a fixed sealed air coupling to the second enclosure at the third opening, the pipe otherwise sealed from the external air; and
a chamber (<NUM>, <NUM>, <NUM>) comprising a drying agent and fourth and fifth openings and being otherwise sealed from the external air, wherein:
the chamber is coupled at the fourth opening by a second rotatable sealed air coupling (<NUM>, <NUM>) to the first enclosure at the second opening; and
the fifth opening comprises a membrane (<NUM>, <NUM>) completely covering the fifth opening, the membrane comprising a material configured to allow air to pass through the material while reducing the passage of water droplets in the air.