Abstract: An earplug is provided, of a type that includes a soft shell (12) and an insertion stem (16), which facilitates pullout of the earplug from the ear canal and which has an increased ability to block noise. The earplug includes a body or shell of soft elastomeric material with a forward portion (20) constructed to enter the ear canal and a rearward portion (22) which flares in a rearward direction. A stem (16) of more rigid material than the shell, extends along most of the length of a passage (14) formed within the shell. The shell passage has a neck part (42) at the rear of the shell forward portion. The stem has a forward flange (32) lying in interference fit within the passage at a location forward of the passage neck part, and the stem has a rearward flange (34) that lies in interference fit with the flared rear portion of the shell.

Abstract: Improvements are described in the injection of ammonia (NH.sub.3) into the exhaust gases of an engine to reduce nitrogen oxides. Instead of merely injecting ammonia into the exhaust gas conduit through a hole in its side, an ammonia injector (90) is provided that projects considerably into the exhaust conduit (16), with the injector having a plurality of holes (94). The ammonia is activated to decompose it into its reactive components, including NH.sub.2 and NH prior to injecting it into the exhaust conduit. Such activation prior to injection can be accomplished by heating the ammonia in the presence of a catalyst such as a metal of the platinum group, iron, nickel, or zinc. In an engine that has a fuel injection system wherein electrical pulses are delivered to fuel injectors to control the fuel flow rate, the durations of these electrical signals are used to control the opening of a valve (72) that controls the flow rate of ammonia into the exhaust gas conduit.

Abstract: An earplug of the slow recovery type is described, which has open cells for expelling gas to the outside during compression, but which resists the entry of water through the outside and the soiling of the outside by dirt. The earplug includes a body formed of pressure-molded slow recovery resilient foam material forming multiple gas-filled shells. The plug body has a surface region forming a skin wherein the average cell cross-sectional area is less than half that of cells at the center of the body, and is less than one-tenth millimeter, the surface region being primarily continuous.

Abstract: A system is provided for changing hydraulic oil in vehicles such as airplanes, which enables rapid replacement of dirty oil and rapid cleaning of oil to meet military/commercial aircraft specifications for reuse. The apparatus includes a frame (40), dirty and clean oil tanks (14, 16) mounted on the frame, a filter tank (30) with filters (32) mounted on the frame, and pump and valve means (20) for controlling the flow of oil. Initially, the apparatus is rolled up to an airplane, dirty oil in the hydraulic reservoir of the plane is pumped into the dirty oil tank, and clean oil from the clean oil tank is pumped into the airplane reservoir. Thereafter, while the apparatus is moved or is stationary, dirty oil from the dirty oil tank is pumped through filters of the filter tank and into the clean oil tank for an initial cleaning, and thereafter the oil is continually circulated from the clean oil tank through the filtered tank and back to the clean oil tank to polish the oil.

Abstract: A rotary fluid valve has a pivotable disk (36) with through slots (38, 39), the disk blocking outer ends of ports (31, 32) in a neutral disk position. When the disk pivots in first or second directions from the neutral position, one of its slots moves into line with one of the ports. This allows pressured air to flow from the now-uncovered port and through the disk slot, and through an upper chamber (46) lying against the upper face of the disk, to allow air to flow between an external fluid coupling (17 or 18) that is coupled to the port, to another external coupling (19, 20) that is coupled to the upper chamber, as to inflate or deflate a vehicle air bag.

Abstract: An apparatus useful for detecting the speed and/or position of an object moving along a defined path and more particularly to such an apparatus configured to minimize the spacing between a sensing face of the apparatus and a target surface on the object. Embodiments of the invention are particularly suited for sensing the speed of a rotating member, e.g., a gear, by utilizing a sensor, such as a Hall-effect sensor, to detect the movement of each gear tooth past the sensor. An apparatus in accordance with the invention is configured to mount the sensor for adjustable positioning along a sensor path between an initial position and a final operational position. Movement of the sensor along the sensor path is restricted, e.g., by frictional engagement, but can be overcome by contact with the target surface so as to move the sensor to its final position with the spacing, i.e., airgap between the sensing face and the target surface, minimized.

Abstract: A marker is provided for use by emergency service personnel entering a room of a building, to keep the door from latching closed while he/she searches the room, and later help him find the door to exit the room, and to indicate to other rescuers that a search is in progress or has been completed. The marker includes a housing (12, FIG. 1) and a door clamp (14) mounted on the housing and constructed to fit on a door to prevent complete closing of the door. The housing holds an audible alarm generator (20) which generates sound beeps to help a searcher find the door in an environment of thick smoke. With the door clamp holding the door ajar, the sound beeps can be heard from outside the room, so another searcher can determine that a search is in progress. The alarm is settable to generate a different pattern of sound beeps, to indicate that a search is in progress, or has been completed. It also generates light flashes. The door clamp can include a length of wire that extends around the outer edge of a door.

Abstract: A vacuum assisted toilet is described, of the type wherein the toilet bowl outlet has a lower trap that is open to the passage of air therethrough except during each flushing when a vacuum is applied, which uses the vacuum more effectively. A vacuum source (46, FIG. 3) includes a first container portion (107) that holds water between flushings, with the water released during a flushing and creating a vacuum in a second portion (106) of the container that is coupled through a vacuum conduit (48) to the toilet bowl outlet. Instead of constantly coupling the second portion of the container to the bowl outlet, the second portion of the container is allowed to progressively expand but remain substantially unconnected to the bowl outlet until a predetermined amount of expansion (to 108) when the second portion is suddenly connected through the vacuum conduit (48) to the bowl outlet.

Abstract: A fluid swivel is described, of the type that carries oil, water or natural gas at high pressure between an undersea well and a weathervaning ship, which has a seal device of increased lifetime. The seal device (56, FIG. 2 ) lies in a cavity of a first swivel part (12) and includes a rigid seal ring (62) that is slidable toward and away from a sealed surface (66). A deformable seal (60) can be backed up by the seal ring, with the seal ring sliding to close the extrusion gap (70) into which the seal could extrude when high pressure fluid enters the swivel. A pressure source (80) coupled to the cavity urges the backup part to deform radially and slide toward the sealed surface with a force that increases as the pressure of fluid in the swivel increases.

Abstract: An illuminated sign assembly is provided, of the type that includes illuminated alphanumeric characters lying on a dark background, wherein the characters and/or color can be readily changed at low cost. The sign includes a thick rigid structural plate (26, FIG. 3) of colorless translucent material which can be readily placed in a lightbox that shines light through the plate. A thin color sheet (30) which passes light of a selected color, lies on the front face of the translucent plate, and an opaque character sheet (34) which has apertures (20) defining alphanumeric characters, lies on the front face of the color sheet. The color and character sheets are each thin, so new color and character sheets can be provided at low cost for mounting on the plate. The color and character sheets each have a layer of water-soluble adhesive so a water spray (62, FIG. 11) can be applied to greatly reduce the adhesive viscosity to enable squeegeeing (at Z) of each sheet to remove air bubbles.