BACKGROUND OF THE INVENTION

Field ofthe Invention:

This invention relates generally to personal service units and systems for generation and dispensing of oxygen for use in situations of emergency decompression aboard aircraft. More particularly, the invention relates to a compression molded personal service unit for providing services to passengers or crew such as ventilation and lighting, as well as a modular system for stowing and deploying an oxygen generator and oxygen masks, for use during decompression or oxygen depletion, or other emergencies aboard an aircraft.

Description of Related Art:

In the course of aircraft operation, passengers and crew aboard an aircraft typically ate provided with controllable ventilation, lighting, and emergency oxygen supplies by a personal service unit (PSU) adjacent to a passenger or crew seat. Passengers or crew may require an oxygen supply and mask system to provide breathing oxygen consistent with physiological demands at altitudes of up to 40,000 feet. Provisions for personal service units and modules within such personal service units for stowage and deployment of an oxygen generation and mask system should account for requirements for quick donning of an oxygen mask, the limited space and volume available aboard an aircraft, the desirability of weight reduction, and reliability ofthe system.

Additionally, conventional personal service unit panel assemblies have typically been formed of aluminum sheet metal, thermoformed plastic or injection molded plastic. Panel thickness is dictated by weight constraints for aircraft, and such panels are typically reinforced by a metal or plastic structure bonded to the back side ofthe

panel to provide stiffness and rigidity. This reinforcing structure also typically includes clips, fasteners, and brackets for installation of components such as ventilation outlets, reading lights, wire harnesses, and the like. It would be desirable to provide personal service unit assemblies with a reduced part count, reduced weight, and reduced costs of tooling, materials, and assembly.

Ease of maintenance of emergency oxygen systems is also an important consideration, especially for aircraft that can seat as many as from 300 to 800 passengers. Following a decompression and deployment of oxygen masks, all expended oxygen generators should be removed and replaced, and all ofthe oxygen masks deployed should be cleaned or replaced. In a conventional system, this requires removing the generator from the oxygen dispensing system module container, disconnecting the masks, cleaning the masks, re-attaching the cleaned masks to the generators, installing the generator in the containers and repacking the masks.

Current conventional designs for oxygen generation and dispensing modules for aircraft are frequently complicated and have a large number of detailed parts that can decrease the reliability ofthe system, due to the chances of improper assembly and due to the increased number of potential modes of failure which are generally a feature of complicated designs, and can lead to improper opening ofthe module door, improper deployment of oxygen masks, entanglement of lanyards and oxygen tubing during deployment, or improper packing or stowage of oxygen masks in the module over the life ofthe unit. It would therefore be desirable to integrate detailed parts of an oxygen module into a container assembly in order to reduce weight by eliminating part count, fastening hardware and bonding processes for attaching various detailed parts to the container, it would also be desirable to reduce the part count to increase reliability, since there would be fewer parts to fail, deteriorate or malfunction during the service life ofthe oxygen dispensing system modules.

Additionally, conventional oxygen generator and mask systems are typically tested by fully deploying the oxygen masks, requiring tedious restowing ofthe oxygen masks, which can lead to improper packing and improper 15 deployment. It would be desirable to provide a test system that allows testing for proper functionality ofthe

deployment system without actual full deployment of oxygen masks, while also aiding in the repacking ofthe masks Particularly aboard an aircraft where restowing of masks must be done anywhere from 300 to 800 times, the effect of fatigue on increasing the chances of improper packing can be of great importance It would also be desirable to provide a system for operating a test release ofthe oxygen masks for a drop test that can prevent the door ofthe container housing from opening fully when the door latch is released, eliminating the need for repacking ofthe masks The present invention meets these needs

SUMMARY OF THE INVENTION Briefly, and in general terms, the present invention provides for a new and improved compression molded integrated personal service unit for use in transport aircraft for providing services to passengers or crew, such as ventilation, lighting, and emergency oxygen The invention also provides improved and easier testing ofthe oxygen dispensing system

In one embodiment, the invention provides for a compression molded integrated oxygen generation and oxygen mask module that can be mounted separately in the aircraft or disposed within the personal service unit, for generating and dispensing oxygen for use in situations of emergency decompression aboard an aircraft The compression molded personal service unit and integrated oxygen modular system utilize composite materials, making them lighter in weight Due to the modular, integrated construction ofthe oxygen dispensing system modules ofthe invention, fewer detailed parts are provided that can interfere with the functioning of doors, hinges and latching and the deployment and stowage of masks The oxygen dispensing system modules container assembly includes multiple parts that are integrally molded into the container body for ease of assembly and lighter weight The chances of improper deployment of oxygen masks are reduced, since fewer parts are provided on the inside ofthe container that can become entangled with lanyards or oxygen mask tubing during deployment Accordingly, the invention Provides for an improved personal service unit for services such as 25 ventilation, lighting and emergency oxygen In one presently preferred aspect ofthe present invention, the personal service unit comprises a housing formed by compression molding of a sheet or

bulk molding material, and means disposed in the housing for providing services to a person in the transport aircraft In one presently preferred embodiment, the personal service unit can also include an integrated modular system for dispensing oxygen for use in transport aircraft, comprising an oxygen dispensing system modules container housing formed by compression molding of a molding material, an oxygen source for providing oxygen to the oxygen dispensing system modules container housing, and oxygen dispensing means to be deployed from the container for dispensing oxygen. In a presently preferred embodiment, the oxygen dispensing means comprises at least one oxygen mask connected to the oxygen source, and the oxygen source comprises an oxygen generator removably disposed in the container housing. The container housing includes a main door, latch means for latching the main door in a closed position,, and latch release means for releasing the main door to move to an open position for deployment ofthe oxygen dispensing means The latch means preferably comprises means for latching the main door and the container housing together The latch release means preferably comprises a door release plate, a latch plunger is having a latch piston aligned to press on the door release plate when the main door is closed to release the latch means, and means for resetting the latch release means when the main door is moved to the closed position

The means for resetting the latch release means preferably comprises a yoke member having a cam surface aligned to engage with the latch plunger, the latch plunger having a corresponding cam surface for engaging the cam surface ofthe yoke member, the yoke member operating to reset the latch plunger piston when the main door is moved to a closed position, and the latch plunger cam surface engaging the yoke member cam surface to pivot the yoke member out of engagement with the latch plunger when the main door is moved to the closed position The main door preferably includes integrated door hinge post receptacles for receiving mounting posts of door hinges In another aspect ofthe invention, the container housing includes integrated profile strip attachments for attachment of lightweight slotted hangers or attachment guides to slide or snap onto the container shell ofthe module. In another presently preferred aspect ofthe invention, the modular oxygen system includes means for testing deployment ofthe oxygen dispensing means. The means for testing deployment ofthe oxygen dispensing means preferably

comprises means for retaining the main door in a partially opened test position In one preferred embodiment, an external test lever is mounted on the main door for preventing the main door from opening fully to allow testing deployment ofthe oxygen dispensing means-without requiring repacking the oxygen masks In another preferred embodiment, a test means is contained inside the container The test means is accessible by a test deployment tool is insertable through an aperture formed in the main door, to prevent tampering or inadvertent deployment ofthe system by passengers

Other features and advantages ofthe present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles ofthe invention

BRIEF DESCRIPTION OF THE DRAWINGS

Fig 1 is a perspective view ofthe modular system for producing and dispensing oxygen for use in transport aircraft,

Fig 2 is a perspective view ofthe modular system of Fig 1 showing the container shell, with the oxygen masks removed;

Fig. 3 is an enlarged view ofthe striker and release plate ofthe multiple release door and latch system ofthe modular system of Fig 1,

Fig 4 is a perspective view of an integrated profile strip and attachment guide or hanger for the attachment system for the integrated module of Fig 1,

Fig. 5 is a perspective view ofthe one-piece door, hinge and mounting system, and a test lever assembly in a closed position of a test system ofthe integrated module of Fig 1,

Fig 6 is a top plan view ofthe container shell,

Fig 7 is a perspective view ofthe test lever of Fig 6, shown in an open and/or test position,

Fig 8 is a perspective view of an alternative test release system, and test deployment tool, for the integrated module of Fig 1,

Fig. 9 is an exploded perspective view of an optional automatic latch reset mechanism,

Fig. 10 is a sectional elevational view ofthe automatic latch reset mechanism of Fig. 9;

Figs. 11 a-c are simple schematic elevational view of, the automatic latch reset mechanism showing the three basic stages of resetting ofthe latch;

Fig. 12 is an exploded view of a personal service unit according to the principles ofthe invention, for use in a transport aircraft;

Fig. 13 is an exploded view of ventilation and lighting components ofthe personal service unit of Fig. 12;

Fig. 14 is an exploded view of an alternative embodiment of an integrated module for producing and dispensing oxygen, for use in the personal service unit of Fig. 12; and Fig. 15 is an exploded view of an aisle light panel assembly for use in the personal service unit of Fig. 12. integrated module for producing and for use in the personal service unit

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Conventional designs for aircraft personal service units and oxygen mask systems for producing and dispensing oxygen in emergency decompression situations typically are complicated and have a large number of detailed parts that can increase the cost of assembly. In such an oxygen supply system, the large number of detailed parts can also decrease the reliability ofthe system, due to the chances of improper assembly, that can lead to improper opening ofthe door or improper deployment ofthe masks, particularly due to entanglement of lanyards and oxygen tubing during deployment. In addition, the multiplicity of parts in such systems can add unnecessary weight to an aircraft

The compression molded personal service unit ofthe invention for providing such services as ventilation, lighting and emergency oxygen preferably utilizes composite materials, is lighter in weight, and has fewer parts compared to current conventional personal service units. The oxygen dispensing system modules container assembly ofthe invention can be mounted separately in an aircraft or contained within the

personal service unit, includes features necessary for generating and dispensing oxygen that are integrated into the container body during fabrication ofthe container, and also preferably utilizes composite materials, is lighter in weight, and has approximately 39 !k fewer parts compared to current conventional oxygen-producing modules The modular oxygen system includes features necessary for generating and dispensing oxygen that are integrated into the container body during fabrication ofthe container Multiple parts are integrally molded into the container body for ease of assembly and lighter weight The reduction in the number of parts leads to increased reliability, since fewer parts exist on the inside ofthe container for entangling lanyards or oxygen mask tubing during deployment, and the opportunity for malfunctioning of doors, hinges and latching mechanisms is significantly reduced. The resulting oxygen dispensing system modules is lighter, easier to build, and costs less to produce than conventional oxygen dispensing system modules

As is illustrated in the drawings, which are provided by way of illustration ofthe invention and not by way of limitation, the invention is embodied in a modular structural system 20 that can be contained within a personal service unit, or mounted separately in an aircraft, for producing and dispensing oxygen for use in transport aircraft With reference to Figs. 1 and 2, the integrated oxygen dispensing system modules includes an oxygen dispensing system modules container assembly 22 and a removable oxygen generator 26 and oxygen dispensing means, such as one or more oxygen masks 28. The oxygen masks are typically connected to the oxygen generator for receiving oxygen and dispensing oxygen to a passenger when the emergency oxygen system ofthe aircraft is activated.

The modular oxygen system includes a main door 30 hingedly mounted to the oxygen dispensing system modules container assembly The main container door 30 preferably includes a door latch assembly 34, which includes one or more release deployment latches 36 connected to the main door by attachments 44, and latching to the container assembly 22 illustrated in Fig. 6. The door latch assembly preferably includes more than on release deployment latch. The one or more deployment latches are connected and driven by a single drive shaft 38, so that when one ofthe door latches is released by the latch plunger or striker 40 striking the door release plate 42, both release latches are

released at the same time The main door 30 also includes door hinge mount receptacles 48, shown in Fig. 5

In one preferred embodiment, the door and latch system includes two or more release deployment latches The multiple release door and latch system facilitates the door shutting in a desirable non-bowed configuration, and provides improved reliability due to an increase in a number of latch points from a traditional single point of latching to two or more points of latching in the door The door latching system is adaptable to containers of different sizes with long door assemblies As the door assembly length increases on various models of aircraft, the ability to latch the door shut in two or more locations can be significant in eliminating drooping or bowing ofthe door The use of a simple striker design that impacts door release plates also improves the reliability ofthe mask deployment, since no side loads are introduced which could cause the latch to bind during the opening and closing ofthe door The tolerance for the latch and door alignment is greatly relaxed, since the latch striker merely strikes the door release plate to release the latch

As is illustrated in Fig 4, the attachment system 52 also preferably includes an integrated attachment guide 54 formed on the edge 56 ofthe container shell 62 A lightweight slotted hanger or profile strip 58 preferably includes an elongated channel or groove 60 to interfit with the integrated attachment guide, so that the profile strip can slide or snap onto the container shell 62, while the other end 63 includes a curved hook portion for engaging a support rail (not shown) The lightweight profile strip is currently preferably formed of aluminum to provide a strong but lightweight profile strip, although other similar strong and lightweight materials may also be used. With the profile strip, a physical force fit is achieved which increases the reliability ofthe attachment system This enhances the structural integrity ofthe module, since no additional mechanical fasteners or adhesives are required

The container assembly also preferably includes attachment locations 64 shown in Fig 4 and 6 for unitary door hinge mounts 66, shown in Fig 5, having door hinge mounting posts 68 that slide into corresponding hinge post mount receptacles 48 in the main door. The one-piece door hinge posts include a locking tab 78

that can fit through and interlock with the hinge receptacles 74 (shown in Fig 4 and 6) molded container shell

The one-piece door hinge mount allows for precise location ofthe door hinge mounting posts in the container. Since the opening is built into the die used to make the container shell, the location ofthe door hinge mount is precise and repeatable The door hinge mounting utilizes snap in methodology, which allows the door hinge post to be quickly attached to the container shell assembly The design of the door hinge mount allows the part to slide into the opening in the container shell and lock into place with no mechanical fasteners or is adhesives. It is also relatively easy to remove the door by depressing the locking tab on the door hinge post and disengaging it from the hinge post receptacle molded into the door, which facilitates repair or servicing ofthe unit in the field The precise position ofthe container door permits the door to consistently open and close and line up with door latch assemblies. This also enhances the flatness ofthe door when closed, which also improves the appearance ofthe unit in an aircraft

As is illustrated in Fig. 5 and 7, a test lever assembly is also preferably integrated into the main door. The test lever can move from a closed position as is illustrated in Fig 5, to an open or test position as illustrated in Fig 7, for testing the deployment ofthe oxygen masks in the integrated oxygen dispensing system modules Movement ofthe test lever to the open position prevents full deployment ofthe integrated oxygen dispensing system modules, also allowing access to the information on the inside of the test lever.

In the test lever assembly integrated into the door, alignment ofthe lever with the door is automatic because the lever is already installed in the door, increasing the functionality ofthe test lever device and door system. Proper alignment ofthe test lever device enhances the appearance ofthe unit in the aircraft. Such a design also eliminates any protrusions or other part assembly configuration which could serve to cause snagging or accidental operation.

Referring to Fig. 8, an alternative embodiment of a test system 94 is illustrated that is contained inside the integrated oxygen dispensing system modules The integrated oxygen dispensing system modules typically includes a latch such as an electric

latch (not shown) for releasing the main door 30 The remote or auxiliary test deployment tool 98 is a separate tool that is preferably inserted into the opening 102 in the door and through the key shaped opening 104 ofthe container flange to prevent the full opening of the door The tool 98 is then typically rotated approximately 90 degrees to prevent removal ofthe tool from the key shaped hole The shoulder 106 ofthe tool is preferably spaced apart from the distal end 107 ofthe tool such that, when inserted, the shoulder of the tool will prohibit the door ofthe integrated oxygen dispensing system modules from falling past the required open door test position during testing This allows observation of successful door opening, and the visual inspection on the edge ofthe exposed door of information such as the date of generator manufacture, lanyard length, number of masks, and other useful information In this alternative embodiment, the conventional opening for a test button is eliminated, and the possibility of inadvertent passenger deployment is therefore also eliminated

With reference to Figs 9, 10, 11 A, 1 IB and 11C, the modular structural system can also optionally include an automatic latch reset mechanism, so that the motion of closing the main door automatically moves the latch plunger 40 to a ready position for releasing the door latches The automatic latch reset mechanism includes a yoke 110 hingedly mounted to the door 30, and having a seat surface 112 for engaging the extended latch plunger or piston 114 disposed in the latch body 116 The yoke also preferably includes a bevelled cam surface 118 adjacent to the latch plunger seat surface 1 12 for slidably engaging a correspondingly bevelled cam surface 120 on the latch body The yoke in an upright position as shown in Figs 9 and 1 la makes contact with the extended latch piston 1 14, to move the latch piston upward as the door is closed, until the latch piston has moved to the reset position in which the ball detent 122 ofthe latch body is seated in the detent seat 124 ofthe latch piston Additional closing movement ofthe door engages the latch body cam surface 120 with the yoke cam surface 118, as shown in Fig lib, rotating the yoke against a spring bias to a position disengaged from the latch body allowing actuation ofthe latch, as shown in Fig lie Additional closing movement ofthe door engages the door hooks to the container, which completes the door closing cycle, so that actuation ofthe latch piston or plunger will release the door hooks

With reference to Figs. 12 - 15, in one currently preferred embodiment, the invention comprises a personal service unit 130 that comprises a housing 132 formed by compression molding of a sheet or bulk molding material. As is illustrated in Fig. 12, the housing ofthe personal service unit can be formed by compression molding interior sections 134 and 136 ofthe housing, a ventilation port and lighting cover 138, an oxygen mask compartment exterior door 140, and an exterior cover panel 142 having an opening 144 for the ventilation port cover. Means are preferably disposed in the housing of the personal service unit for providing services to passengers or crew in the transport aircraft, such as ventilation, lighting and emergency oxygen. As is shown in Fig. 13, the ventilation port and lighting cover includes ports 146 for moveable ventilation nozzles 148 having an associated gasket 150 for sealing connection ofthe nozzle to the ventilation port, and associated gaskets 152 for sealing connection ofthe nozzle to a ventilation supply conduit 154. Lighting assemblies 156 are also provided for insertion in the lighting ports 158 ofthe ventilation port and lighting cover, along with associated electrical circuitry 160 for connecting the lighting assemblies with 10 the electrical system ofthe aircraft. A lighting and service control panel (not shown) can also be provided for controlling lighting and other services, such as audio and video entertainment, and may include a call button (not shown) for summoning assistance of an attendant or the like. Fig. 15 illustrates an alternate embodiment of an aisle light 162 having a light bulb 164 and a light mounting assembly 166 for attachment to a lighting cover panel 168 by associated brackets 170 to a lighting cover panel 172 to be mounted in a personal service unit.

In one presently preferred embodiment illustrated in Fig. 14, the personal service unit can include a compression molded integrated module 174 for producing and dispensing oxygen for use in transport aircraft. The oxygen dispensing system modules includes a container housing assembly 176 also preferably formed by compression molding of a sheet or bulk molding material, and can include an oxygen supply line 178 connected to an oxygen generation source (not shown) , and oxygen dispensing means, such as one or more oxygen masks 180. The oxygen masks are typically connected to the oxygen supply for receiving oxygen and dispensing oxygen to a passenger when the emergency oxygen system ofthe aircraft is activated. The integrated oxygen dispensing

system modules also includes a main door 182 hingedly mounted to the oxygen dispensing system modules container assembly, and means for latching the main door in a closed position and for releasing the main door to move to an open position for deployment ofthe oxygen dispensing means. The main oxygen dispensing system modules door also preferably includes room to inscribe information 184 such as the date ofthe generator manufacturer, the number of masks in the container, and the lanyard lengths inside the container, as well as other useful information.

In a presently preferred aspect ofthe invention, the personal service unit housing and the oxygen dispensing system modules housing can be formed by compression molding of a sheet or bulk molding material. As is well known in the art, in compression molding, a molding material such as a preshaped part, a volume of molding powder, a viscous mixture of liquid resin and is filler material, or a prepreg molding material that can be partially cured is placed in a mold cavity in a lower half of a mold die. Forming ofthe material is typically accomplished by application of heat and pressure with an upper half of the mold die, similar to forging. The molding material is typically a thermosetting plastic, which is frequently in a partially polymerized state. Cross-linking of the thermosetting plastic is allowed to occur in-the heated mold, for a period of time ranging typically from about 0.5 to 5 minutes.

One preferred type of sheet molding materials for use in compression molding in the present invention is the type of sheet molding compounds made ready for fabrication by combination of a thermosetting resin with a reinforcing fiber material, other modifiers can also be included in the sheet molding compounds, as desired, and as is well known by those skilled in the art. One preferred type of sheet molding compound is vinyl ester such as that sold under the trade name QC-8800, available from Quantum Composites, Inc. of Midland, Michigan. QC-358800 typically is available in a rolled sheet form approximately 0.125 inches thick, with a glass fiber content of approximately 62 per cent, and glass fibers having a length of about one inch, although other fiber lengths and contents are available. The material can also optionally include a flame retardant, or other modifiers. The material is typically compression molded at a temperature of from about 270° to about 300°F, with a molding pressure of about 300 to about 1,000 psi. A typical

0 25 inch section will cure to a rubbery consistency in about 3 to 5 minutes at a temperature of about 280°F Other reinforcement materials that can be used include metal fibers, silicon carbide fibers, mineral fibers such as boron, graphite, carbon fibers, aramid fibers, glass spheres and flakes, natural fibers such as cotton or jute, synthetic fibers such as acrylic and is rayon, and the like other sheet or bulk molding systems that can also be suitable for compression molding in the invention include polyesters, epoxies, phenolics, silicones and polyimides, for example Compression molding temperatures of 350°F or higher, and pressures of up to 2,000 psi are typical

It should be noted that integrating several ofthe parts into the container assembly reduces weight compared to conventional oxygen dispensing system modules systems, by limiting the part count, fastening hardware and bonding processes for attaching parts to the container Use of composite materials in the design also reduces weight, while providing strength required for transport aircraft Reducing the part count increases reliability, since there are fewer parts to fail, deteriorate or malfunction during the service life ofthe integrated oxygen dispensing system modules Reduction ofthe number of parts is achieved, since many ofthe parts are molded as part ofthe container shell, such as the attachment guides for the profile strips, attachment locations for the door hinge mounts, attachments for the door latch mechanism and door release hooks, and the door hinge mount receptacles and door release hooks

Although the embodiments described have generally utilized a chemical oxygen generator as the oxygen source, it is possible within the intended scope of this invention to install as an oxygen source a manifold, which is connected to a remotely located oxygen supply The remotely located supply could include any ofthe oxygen supply means known in the art, such as, for example, a remotely located chemical oxygen generator, a compressed gas container, a liquid oxygen system, a device concentrating oxygen from the air, or a device producing oxygen by the electrolysis of water, or a combination of two or more such supply means.

It will be apparent from the foregoing that while particular forms of the invention have been illustrated and described, various modifications can be made

without departing from the spirit and scope ofthe invention. Accordingly, it is not intended that the invention be limited, except as by the appended claims.