The Invention relates to clean rooms, such as clean rooms used to control contamination in the pharmaceutical and electronics industries. The Invention is a structural light fixture for use in a ceiling of a clean room and is a ceiling system that includes the structural light fixture. The Invention also is a method of constructing a ceiling using the structural light fixture and is a method of maintaining the light fixture in the clean room ceiling. The structural light fixture of the invention strengthens the ceiling and maintains security from contamination within the clean room while allowing servicing of the light fixture from within the clean room.
Clean rooms are used to control the environment and prevent contamination of product, equipment, materials and processes in the pharmaceutical, biotechnology, life sciences and technology industries. A clean room may take the form of a building-within-a-building, with a clean room envelope within a larger building envelope. The larger building protects the clean room from the elements, contains mechanical systems serving the clean room and may provide structural support to the clean room. The clean room provides a discrete space in which the operator can separately control the temperature, humidity, cleanliness and air pressure.
The ceiling of a clean room may support more than the weight of the ceiling. For example, the ceiling may support the weight of equipment, such as HVAC, electrical, gas, or water utilities or other equipment serving the clean room and the weight of installers or users walking, crouching or crawling on the ceiling to install or maintain the equipment. Clean rooms may utilize composite construction, with walls and ceiling composed of opposing steel panels bonded to an aluminum honeycomb core. For reduced weight and cost, the composite panels are constructed to be as thin as possible, consistent with the structural requirements of the ceiling and walls.
The Invention is a light fixture that also serves the purpose of a structural beam to support adjacent ceiling components of a clean room ceiling, all while segregating the interior of the clean room from the exterior. The structural light fixture allows servicing of a lamp and power supply from the interior of the clean room without interfering with the barrier created by the structural light fixture to the movement of liquid, gas, contaminants or disinfectants through the clean room ceiling.
The structural light fixture includes two nesting, inverted U-shaped beams; namely, an outer U-shaped beam and an inner U-shaped beam. Each of the inner and outer U-shaped beams is unitary and composed of a single extrusion, preferably composed of aluminum. The outer U-shaped beam is secured to the surrounding components of the ceiling, such as composite panels, in a mutually supporting relationship. The top and sides of the outer U-shaped beam are closed and do not define openings communicating through the structural light fixture. The unperforated outer U-shaped beam, combined with the fluid-tight joints between the outer U-shaped beam and the adjacent components of the ceiling, prevent air or other gas from moving between the atmosphere inside the clean room and the atmosphere outside the clean room by leaking through or around the structural light fixture. The closed and unperforated outer U-shaped beam also prevents movement of liquids, particulates, disinfectants, microorganisms or other biological material across the structural light fixture between the interior and exterior of the clean room.
The outer and inner U-shaped beams each defines an interior volume and an open side. The inner U-shaped beam nests within the outer U-shaped beam so that the inner beam interior volume is largely contained within the outer beam interior volume. The open sides of both the inner and outer U-shaped beams are oriented toward the interior of the clean room when the structural light fixture is installed in the clean room ceiling. The inner U-shaped beam is selectably attached to the outer U-shaped beam and reinforces the outer U-shaped beam. The strength and stiffness of the combination of the inner and outer U-shaped beams is greater than the strength and stiffness of either the outer U-shaped beam or inner U-shaped beam alone.
The inner U-shaped beam supports lamps, which may be LED lamps, that are the source of light. The lamps may use any other technology to generate or distribute light, such as light-emitting capacitors, light pipes, or fluorescent or incandescent lamps. The inner U-shaped beam also supports the power supply for the LED lamps and a lens covering the LED lamps. The power supply may include a back-up battery to illuminate the lamps in the event of a power failure.
When the structural light fixture is installed in a clean room ceiling, the combination of the inner and outer U-shaped beams reinforces adjacent ceiling panels or other ceiling components and increases the strength and stiffness of the ceiling compared to a ceiling that does not include the structural light fixture having inner and outer U-shaped beams. The combination of the inner and outer U-shaped beams is capable of sharing a load applied to an adjacent ceiling components and is capable of transferring a load to the adjacent ceiling component.
A lamp is located within the inner U-shaped beam interior volume and is configured to project light through the open sides of the inner U-shaped beam and outer U-shaped beam into the interior of the clean room when the structural light fixture is installed in the clean room ceiling. A lens covers the lamp and may be resiliently retained within the inner U-shaped beam. The inner U-shaped beam is releasably retained by the outer U-shaped beam by fasteners such as screws or clamps. The fasteners may be disposed under the lens and accessed when the lens is removed. Removing or releasing the fasteners or clamps allows a user to remove the inner U-shaped beam from the outer U-shaped beam when the user is within the clean room. Removing the inner U-shaped beam allows the user to service the power supply and the lamp without jeopardizing the liquid- and gas-tight seal between the interior and the exterior of the clean room.
The ceiling system of the Invention includes the structural light fixture, one or more other ceiling components that selectably mate with structural light fixture, flush beams to support the structural light fixture and the other ceiling components, and cables or rods to support the flush beams. The other ceiling components to which the structural light fixture may be attached include ceiling panels as described above, other structural light fixtures, utility races, other structural beams, or any other ceiling component.
To support the structural light fixture and other ceiling components, opposing flush beams extend between the tops of opposing clean room walls or are disposed at the top of opposing clean room walls. The top of the flush beam defines a channel. The channel can receive one or more cable or rod fasteners for attachment to cables or rods. The cables or rods attach the cable or rod fasteners to the building structure and can support the flush beam intermediate to the opposing walls. Each flush beam defines a shelf at the bottom of the flush beam extending the length of the flush beam. Hook ends are disposed at opposing ends of the ceiling components, such as ceiling panels and the structural light fixture, and engage the shelves of opposing flush beams. Each flush beam shelf has an upright ridge that extends the length of the flush beam shelf. The ridge of the flush beam shelf engages a mating groove on the hook end. The ridge and mating groove align the flush beam and ceiling component.
In the system of the Invention, the structural light fixture and other ceiling components are joined by slots and splines. The structural light fixture defines a longitudinal slot on either side of the structural light fixture and extending the length of the structural light fixture. The longitudinal slots of the structural light fixture correspond in location to component slots defined by other ceiling components on either side of the structural light fixture, such as ceiling panels, utility raceways, other structural beams, and other structural light fixtures. A connecting spline is inserted into adjoining longitudinal slots and component slots during installation, sealing the junction between the adjacent structural light fixture and other ceiling components. The spline may be composed of a metal, such as aluminum, or a polymer, and prevents or reduces liquid or gas penetration between adjacent ceiling components.
The splines also serves to transmit a load applied to one ceiling component to adjacent components, such as other structural light fixture or ceiling panels. For example, a load applied to a ceiling panel may be transmitted to an adjacent structural light fixture by the spline. The splines therefore structurally join the structural light fixture to other ceiling components in an integrated whole.
As an alternative to the ceiling system described above, the system may dispense with flush beams. Instead, each of the ceiling components, including the ceiling panels, utility raceways, structural beams, and other structural light fixtures define slots in each of its four sides. Each slot is disposed opposite a slot in an adjoining ceiling component. Each pair of adjoining components is connected by a spline mating with the adjoining slots. Because of the lack of flush beams, the ceiling components are suspended directly from the building structure, as by rod or cables attached to plates bolted to the ceiling components. For this alternative system, the structural light fixture and ceiling components described above dispense with the hook ends. The structural light fixture is attached to adjoining ceiling components by splines in the slots on each of the opposing ends and by splines in longitudinal slots on opposing sides of the structural light fixture. In all other respects, the structural light fixture of the alternative ceiling is the same as the structural light fixture of the ceiling utilizing flush beams and as described above.
The bottom side of the structural light fixture may be coated with PVC and may be solvent-welded to adjoining ceiling components to seal the junction between the structural light fixture and other ceiling components, as against the passage of liquid, biological or other contaminants and against the passage of disinfectants or gas. Alternatively, the bottom side of the structural light fixture may be composed of, for example, powder-coated aluminum and the junction with other ceiling components may be sealed with a suitable sealant, such as a silicone caulk.
The method of installation of the Invention is a method of installing a clean room ceiling that includes the structural light fixture of the Invention. To install the clean room ceiling, an installer will install support rods or cable to the building structure and will install opposing flush beams that are suspended by the support rods or cables. The installer will obtain the structural light fixture as described above having nesting inner and outer U-shaped beams and hook ends. The installer will place the hook ends in engagement with the opposing flush beams. The installer will place splines in longitudinal slots of the structural light fixture and in the component slots of adjacent ceiling components. The user will seal the joints between the structural light fixture and adjacent ceiling components, either by solvent welding or by apply a sealant.
The method of maintaining the structural light fixture is applied after the structural light fixture is installed in the clean room ceiling. While located in the interior of the clean room, the user may remove the lens from the inner U-shaped beam and may repair or replace the lamp. The user may then remove or otherwise disconnect fasteners or clamps connecting the inner U-shaped beam to the outer U-shaped beam. The user may then remove the inner U-shaped beam and repair or replace the power supply and/or battery backup. Assembly of the structural light fixture is the reverse of disassembly.
Servicing of the structural light fixture from inside the clean room provides advantages to the user and to the clean room designer. First, access to the sealed structural light fixture from inside the clean room avoids any issues with movement of gas, liquid, or contaminants through the structural light fixture. Second, access to the top of the clean room ceiling may be limited by the physical dimensions of the space above the clean room ceiling and by HVAC, gas, water, electrical or other utilities or equipment installed above the clean room ceiling. Servicing the structural light fixture from inside the clean room avoids any issues with physical access to the top of the clean room ceiling. Third, servicing of the structural light fixture from inside the clean room also provides the clean room designer with greater flexibility, since the designer can select the location of HVAC, gas, water, and electrical or other utilities or equipment above the clean room ceiling without regard to providing access to the structural light fixture from above.
The invention is a structural light fixture 2 that is a component of a ceiling 4 of a clean room 4.
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The inner U-shaped beam 12 is shown in cross section in
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The load sharing provided by the splines 70 between the structural light fixture 2 and the other ceiling components 60 makes the ceiling 4 stiffer and stronger than it would otherwise be, allowing otherwise identical components 60 to span longer distances than would otherwise be the case, or allowing the other ceiling components 60 to be constructed from lighter, thinner, weaker and hence less expensive materials than would otherwise be the case.
The junction between the structural light fixture 2 and the other ceiling components 60 may be sealed. The junction can be sealed by solvent-welding a polyvinyl chloride (PVC) coating on each of the ceiling components 2, 60 to the adjoining ceiling component 2, 60 by dissolving the adjoining PVC coatings with an organic solvent and allowing the solvent to evaporate, joining the two PVC coatings. Alternatively, the adjoining ceiling components 2, 60 may be sealed by use of a sealant, such as silicone caulk, applied to the junction.
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In this document, elements of the same name and number on one figure or relating to an embodiment have the same or equivalent meaning when the element number is shown on another figure or in relation to another embodiment. The following are the numbered elements shown in the drawings and described in the specification.
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