Abstract: Method of fabricating attenuation sandwich panels having a central cellular core positioned between and bonded to an imperforate facing sheet on one surface thereof and a perforate facing sheet with an outer layer of porous fibrous material adhered to the other surface. The combined perforate sheet and porous fibrous material have a predetermined open surface area prior to attenuation panel fabrication. The perforation exposed surface of the combined perforate sheet and porous fibrous material is covered with a maskant material which covers the surface only. The porous fibrous surface is then saturated with a liquidous anti-wetting solution which coats substantially all of the fibers. The solution is allowed to dry and the maskant is then removed from the opposite surface. The components making up the panel are then assembled and bonded together to form the attenuation panel.

Abstract: The materials to be chem-milled are coated with a maskant material, a template having a specific hole pattern is then placed over the masked surface of the material. A laser beam is then directed towards the template and is scanned either manually or by numerical control means along the hole pattern. The laser is maintained at each hole for a sufficient length of time to enable the maskant to be burned from the material. The material is then chem-milled by any conventional means thereby forming holes through the material at the maskant free areas. The remaining maskant is then removed from the surface of the material.

Abstract: Method of manufacturing broad band noise attenuation sandwich panels utilizing a cellular core positioned between and bonded to two facing sheets by an adhesive bonding system. One facing sheet is perforated and the other imperforate. A thin sheet of porous fibrous felt or fabric is bonded to the outer surface of the perforate sheet. The adhesive layer, at least between the perforate sheet and the porous fibrous material, is sufficiently thick to isolate the two components and form a funnel shaped opening necked down at the entrance to each perforation. In one embodiment a thin layer of non-metallic cloth is positioned between the perforated and porous fibrous material in those areas where cutting, trimming or drilling of the completed structure is required to maintain isolation.

Abstract: A method of manufacturing a perforate material from wire mesh for honeycomb noise attenuation and the resulting material therefrom comprising the steps of selecting a sheet of wire mesh, constructed from a material that can be readily diffusion bonded; cleaning the selected wire mesh to remove all grease therefrom, suspending the sheet of selected wire mesh within a furnace, evacuating the oven to about 10..sup.5 torr, elevating and maintaining the furnace temperature to facilitate diffusion bonding of the contacting cross-over areas of the strands of the wire mesh; reducing the furnace temperature, removing the sheet of diffused wire mesh from the oven when its temperature is below its oxidation level. The furnace may additionally be charged with an inert gas to decrease the cooling time. In some instances a heat dispersing member is inserted between the sheet of wire mesh and the source of the elevating temperature.

Abstract: An accessory for a jet engine for tuning turbine exhaust gases for maximum thrust capabilities in the absence of a turbine thrust reverser and cowling combination normally for and utilized thereon. The accessory comprises an inner streamlined nozzle shell forming a continuation of the outer skin of the turbine exhaust duct, a center mounted engine plug providing a path for the turbine gases between the inner nozzle surface and the engine plug outer surface and a transition adapter for mating and attaching the plug to the center of the engine. The engine plug is further provided with an opening between its engine attached and outer ends providing communication between the engine and the atmosphere adjacent the rear end of the plug. The accessory further comprises a fairing for attachment to the pylon supporting the engine to further tune the gases leaving the nozzle.

Abstract: A three link system in combination with the linear translation of a rear cowl section for non-linear rotation of each of a plurality of blocker doors for providing constant engine pressure characteristics during all positions of blocker door rotation between stowed and fully deployed. A first link is pivotally attached at one end to the engine and pivotally attached at its other end to a second link member which in turn is pivotally attached at its other end to the blocker door. A third link member is pivotally attached to the engine rearward of the first link connection and pivotally connected at its other end to the second link intermediate the end of the first link and blocker door. Actuators are provided for linear translation of the rear cowl section.

Abstract: An integrated thrust reverser vertical thrust control and divergent nozzle for controlling the exiting gases from a thrust producing aircraft engine. The nozzle comprises at least two nozzle reverser doors that are pivotable about a fore and aft aircraft pivotal connection and an actuator system for pivoting the doors. The pivotable connection at each pivot point is remotely disengageable allowing the doors to selectively pivot about either their forward or aft connection. The doors can be positioned through an infinite number of different positions through their travel about either pivotal connection. When in a forward thrust mode the two nozzle reverser doors pivot about their forward pivot point, when in a reverse mode about their aft pivot connections and a combination of forward and aft pivot connections for aircraft vectoring.

Abstract: A thrust reverser for a fan jet engine enclosed by an engine nacelle. The nacelle has a forward section fixed to the aircraft structure and a rearward translatable section attached to the forward section. The nacelle forming a secondary fan nozzle. A pair of blocker doors are pivotally attached to the rearward translatable nacelle section. Drag links are pivotally attached to the forward nacelle section and one of the drag link connects to each blocker door. A cascade ring is fixedly attached to the rear nacelle section and is translatable therewith for positioning within the opening between the nacelle portions when the rearward section is in a translated position. An air motor with drive connections to a plurality of ball-screw actuators provides the means for uniformly translating the rearward section. A recess in the inner surface of the rearward section is provided for the stowing of the links in a position out of the engine gas flow stream when the rearward section is in its stowed forward position.

Abstract: A water jet inlet as used in a surface effect ship, cavitation free environment is provided of a fixed round or rectangular inlet geometry, within the confines of inlet velocity ratios pertaining to the ship velocity immersion design profile. An additional embodiment is disclosed that enables the instant invention to operate at a range of drop fractions, including negative drop fractions, and allows for a truly flush inlet, resulting in minimizing the drag of the ship and potential ingestion of large floating debris.

Abstract: The creation of controlled hole sizes and locations in uncured reinforced thermo setting plastic material by mechanically perforating the uncured material and "B" staging the material surrounding the perforation by sonic vibration of the mechanical perforating device.

Abstract: The invention pertains to apparatus for preventing the flooding of an enclosed plenum chamber pressurized by a source of pressurized gas provided through a duct system leading from a plenum chamber open to the surface of the water over which the ship rides. The inlet to the duct system located within the open plenum chamber is formed to reject by deflection a substantial quantity of water adjacent the inlet from entry. Any small amount of water entering the duct that is not initially rejected from the inlet is ramped through the duct and collected in a stern holding tank. The holding tanks include a float controlled water exhaust valve that opens to the atmosphere and exhausts that collected water therein with the aid of plenum pressure. Any water reaching the closed plenum chamber is constantly exhausted therefrom through apertures in its walls. An additional embodiment is disclosed that prevents substantially all water from entering the enclosed plenum chamber.

Abstract: An overhead lighting fixture with the housing having an open bottom, a resilient hinge pivotally fastening a first side of the light transmitting panel to a first side of the housing adjacent the open bottom of the housing, and a latch assembly for detachably securing a second side of the light transmitting panel to a second side of the housing adjacent its open bottom. The second side of the housing is an elongated extruded side panel member having a light housing web portion and a latch web portion that lies in a plane approximately 90.degree. thereto. The latch member has a J-shaped configuration with a head, a body, and a foot. The head of the latch member has a circular lateral cross-section that is matingly received in a groove formed in the latch web portion. This structure permits the latch member to be pivoted laterally into and out of engagement with a lip extending along the length of the light transmitting panel that rests in the curved hook surface of the J-shaped latch member.

Abstract: This process comprises the steps of depositing a suitable maskant which is resistant to the chemicals used in chem-milling on a back-up sheet such as thin plastic, punching or cutting the desired pattern to be removed from the sheet metal through the maskant and the back-up sheet, then applying the maskant by adhering the same to the sheet metal surface with the plastic back-up sheet on the outside surface. The back-up sheet/maskant combination is placed on both sides of the sheet metal where the thickness of the sheet metal requires chem-milling from both surfaces. For thin metal, one surface of the material can be directly coated with the maskant while the other surface employs the back-up sheet/maskant combination.

Abstract: An electronic circuit for inhibiting overconduction of power transistors utilized in a switching mode and driven by a square wave signal of selected frequency. A reference voltage is utilized to compare the conduction of the transistors. The signal produced as a result of the comparison is utilized to control the base drive to that transistor through a logic circuit. Timing means is provided to delay the turn on or tuen off of the drive signal responsive to the comparison signal.

Abstract: A planing seal for a vehicle having a hull with downward extending sidewalls. The seal comprises a plurality of juxtaposed supporting stays positioned parallel to and between the extended hull sidewalls. These supporting stays are connected to the hull at their forward end and remain free at their rearward end. A plurality of forming cables are attached to the hull at one of their ends and at least one of the plurality of cables attach to at least one of the supporting stays intermediate its ends. The cables have a length selected to provide a curvilinear form to the supporting member which allows independent freedom of movement of the stays toward the hull cable attach point. A flexible, non-permeable membrane extends the width of the hull between the sidewall extensions. The membrane has a spaced-apart sealed attachment to the hull fore and aft. The combination of the extended sidewalls and membrane hull attachments provide a pressurizable plenum chamber with seals supported by the stays.

Abstract: The creation of controlled hole sizes and locations in uncured reinforced thermo setting plastic material by mechanically perforating the uncured material and "B" staging the material surrounding the perforation by sonic vibration of the mechanical perforating device.

Abstract: A pierce rivet machine for simultaneously pierce riveting sheets of material to the opposing flanges of a channel shaped member having a first and a second pierce rivet driver, a first and a second pierce rivet holder for respectively holding rivets for said first and second pierce rivet drivers, and a first and a second anvil each respectively positioned to function in conjunction with the operation of said first and second pierce rivet drivers. The first and second pierce rivet drivers are positioned diametrically opposed to each other. A drive rod supports each pierce rivet driver and attached to the end of the drive rod is a link member and bellcrank for driving the drive rod along an axial reciprocating path. A tie bar has its ends pivotally attached to the bellcranks causing the drive rods to be simultaneously actuated. One of the bellcranks has its end pivotally attached to an air cylinder motor that operates the machine.

Abstract: A vehicle seat assembly having adaptability for use as both a side facing seat positioned along the side walls of various model vehicles and as a front facing seat along the rear wall of various model vehicles. The assembly has a plurality of seat modules, the combination being any mix of the single occupant or double occupant variety. Each of the seat modules has a shell-like structure with a back portion and a seat portion, both of which have a concave outer contour configured to receive a human body. Side flanges are integrally formed along the edges of the seat and back portions. A plurality of end arm members are provided and each has a panel section and inwardly extending flanges for supportably contacting the side flanges of the seat module. The arm member flanges have a back portion support flange and a seat portion support flange. Interlocking structure is formed on the rear of the end arm members for engaging interlocking structure on the front of seat mounting adaptor members.

Abstract: An acoustical laminate comprising multi-ply glass fabric impregnated with an epoxy resin and a method of manufacturing the laminate. The laminate may be bonded to suitable backing, such as a honeycomb core with a solid backing, to produce an acoustical panel. The panel provides excellent, substantially linear, sound absorption characteristics.