Abstract: A stamp formed muffler is provided with a nonplanar array of tubes. The tubes are defined by at least one pair of nested formed members. The nested members include at least one external shell having a nonplanar portion and at least one internal plate having a nonplanar portion, with the respective nonplanar portions being configured to be placed in generally nested face-to-face relationship. The nonplanar configuration comprises an array of channels, such that an array of tubes is defined by the channels when the components are placed in nested relationship to one another. One or more chambers of the muffler are defined adjacent the nested formed members. The chambers may be defined by a single plate placed in register with the nested components or by a second pair of nested members. The nested pairs of formed members is effective in dampening shell noise attributable to vibration of the formed members.

Abstract: A noise reducing apparatus is disclosed, comprising a lens-type hollow body consisting of a plurality of inclined hollow tubular passages. The lens-type hollow body has a plane incident surface and a curved emission surface and the length L.sub.2 of the hollow tubular passage is optimized in accordance with relevant dimensional parameters of setting of the lens-type hollow body in a sound field, to reduce noise from a spot sound source efficiently.

Abstract: A sound insulating lining for a gas flow path, particularly the bypass flow ath in a jet engine, is made up of a succession of acoustic panels including a perforated skin bonded to a stiffening frame, and a cellular structure formed by a ribbed skin clamped with prestressing via of resilient tongues to transverse struts of the stiffening frame so that the ribs engage the perforated skin to form resonant acoustic cavities. The panels forming the lining are screwed to the casing constituting the wall of the flow path to be insulated.

Abstract: A pressure gradient pickup, particularly a capacitor microphone or a dynamic microphone, has a diaphragm arranged in a housing and at least one sound entry opening which conducts the sound to the rear side of the diaphragm. Acoustically acting phase-shifting sections are connected in the interior of the housing to the at least one sound entry opening. The at least one sound entry opening is located at least approximately in the same plane as the diaphragm and is preferably arranged concentrically relative to the diaphragm edge.

Abstract: A kit includes a self-contained muffler which attaches to the output exhaust system of a small two-cycle engine, such as a model engine that is in the range of 0.15 to 1.25 cubic inches displacement. The kit provides a low cost adaptation of existing engine manifolds to meet required sound reduction guidelines of below 90 Db at nine feed from the engine. The kit is easily adapted and installed on a wide variety of manifold-muffler adaptations, for example model engines using a mounting bolt which clamps the kit muffler to a portion of the existing engine muffler.

Abstract: An integrated slip guide member and slip table assembly for use with business machines. The slip table has a first and second groups of parallel grooves thereon which are spaced apart in parallel relationship. The slip guide member has first and second members which receive the a portion of the slip table to enable the guide member to be moveable on the slip table to accommodate different widths of documents. The slip guide member also has detent members thereon to mesh with the first and second groups of parallel grooves to adjustably secure the slip guide member on the slip table.

Abstract: An exhaust muffler for an internal combustion engine, comprising a hollow casing defining a plurality of chambers which are communicated with each other by way of small holes, an exhaust inlet tube fixedly attached to an exhaust port of an internal combustion engine at its one end and fitted into the casing from a hole provided therein for communication with one of the chambers at its other end, and an exhaust outlet passage communicating another one of the chambers to the atmosphere. The internal end of the exhaust inlet tube and an opposing casing wall are joined by a threaded fastener while the exhaust inlet tube is provided with an annular shoulder surface which fits into the hole of the casing in an air tight fashion, so that the mounting of the muffler can be accomplished simply by fitting the casing of the muffler onto the exhaust inlet tube which is typically attached to a cylinder head of an internal combustion engine in advance and tightening the threaded fastener.

Abstract: A navigational calculator (10) for establishing the ratios of time, or distance, to be spent on port or starboard tacks, respectively, during the maneuvering of a yacht to a windward destination. A plurality of disk members are carried on a central support (11). The first disk member (14) has a true wind indicator (30) imprinted thereon. The second disk member (15) has a compass rose (34) imprinted thereon. The third disk member (16) has a course indicator (35) and two sets (38 and 39) of tack ratio indicia imprinted thereon. The fourth and fifth disk members (18 and 19) have starboard and port heading indicators (46 and 55, respectively) imprinted thereon. The sixth disk member (20) has included tacking angle indicia imprinted thereon and a tack ratio indicator (61) alignable with one set (38) tack ratio indicia. The seventh disk member (21) has included tacking angle indicia imprinted thereon and a tack ratio indicator (66) alignable with the other set ( 39) of tack ratio indicia.

Abstract: The component parts of a hearing aid are releasably inserted into the inside of mounts to be secured in the interior of the hearing aid housing. The mounts are provided at their inside with an elastic material that is preferably fashioned as a plurality of nubs and that exerts an elastic spring power onto the inserted component parts. The mounts can hold component parts of different sizes and are also sound-absorbing.

Abstract: An underwater communicator comprising a transmitter for transmitting acoustical energy between mediums having differing impedance. The transmitter includes first and second ends. The first end is exposed to a first medium while the second end is exposed to a second medium. In the preferred embodiment, the transmitter is formed from a material having a substantially identical impedance to the second medium. An acoustical lens is positioned adjacent the first end of the transmitter. The acoustical lens has a substantially planar front face and a substantially concave shaped rear face. The acoustical lens includes a plurality of spaced vertically extending plates. The vertically extending plates form a substantially right angle with the front face of the acoustical lens. A plurality of spaced plates intersect the vertically extending plates and form an acute angle with the front face of the acoustical lens, thereby forming a plurality of inclined passageways.

Abstract: An improved molded air inlet device such as an air silencer for an outboard motor that provides a very effective atmospheric air inlet area and which can be easily molded without restricting the flow into the device.

Abstract: An earplug uses damping to render unimportant a Helmholtz resonance between the acoustic mass intrinsic to a sound channel thereof and the compliance of air in the earcanal unimportant, in combination with an external structure coupled to the sound channel to increase response characteristics at higher frequencies in a predictable and well controlled manner in order to provide a highly desireable uniform frequency response.

Abstract: An ear tip for use with a stethoscope, audio headset or like device, the ear tip being of a construction and design that provides substantial deformation of the ear tip under normal stethoscope pressures such that in use the ear tip is seated comfortably and conformably against the ear canal opening.

Abstract: A dripping sound generating apparatus which comprises a dripping sound echoing or resonating member having a cavity inside and a hole at least at the top portion of the member. The apparatus is adapted to allow liquid to enter the member and positively retain the liquid at a lower inside portion of the member. The apparatus also includes a dripping device for producing liquid drops and permitting the liquid drops to fall from the top portion of the member onto a pool of the liquid retained at the lower inside portion of the member and a device for recycling the liquid having dripped for repeated dripping. The apparatus is capable of providing varied dripping sounds over a long time by controlling the amount of the dripping liquid.

Abstract: The invention provides a method and apparatus for manually counting pills or similar objects. Pills in excess of a required number are deposited in a counting area which has the general shape of an equilateral triangle and is defined by walls which surround all but a small open peripheral range of the area. The excess pills are separated from the required number on the counting area, and the user tilts the apparatus to cause the excess to slide out of the area through the open peripheral range while retaining the required number in the counting area. The user then tilts the apparatus to cause the required number of pills to slide out of the area through the open peripheral range.

Abstract: The check positioning system includes a guide tray (12) which in turn includes a guiding edge (31). Roller assemblies (18,20,22) in combination with associated lower gripping wheels (40,42,44) and a system (16) for driving the roller assemblies (18,20,22) move the check longitudinally in both directions along the guide tray (12). A clamping apparatus (48) controls the clamping of the check. A deskewing roller (28) on each of the roller assemblies moves the check laterally as well as longitudinally when the check is not clamped. A laterally movable edge detector (14) detects the edges of the check so it can be located relative to the guide tray (12) for accurate printing/encoding of the check.

Abstract: The invention is directed to a compact noise abatement muffler for an internal combustion engine. The muffler includes a housing having a plurality of chambers and fluid conductors for enabling the exhaust gases passing through the muffler to achieve at least 4 changes of direction of gas flow. The muffler of the invention is capable of reducing the sound pressure level of the exhaust gases between the input and exhaust ports of the muffler in the range of 10-25 decibels.

Abstract: An apparatus for permitting the viewing of a large number of entries permitted on a sheet leaving a calculating machine includes an elongate bar having a longitudinal track, a support plate having a lower end fitted in the track and an elongate fastening device connected to the elongate bar and extending transverse to the length of elongate bar. The track supports the support plate fitted therein at an angle of between 35 and 70 degrees with respect to the horizontal and has a length greater than a width of the support plate so that the position of the support plate along the track may be adjusted. The support plate includes flanges for laterally guiding longitudinal edges of the sheet supported therein. The elongate bar may be secured to the calculating machine by the fastening device at a position where the sheet leaving the calculating machine may be supported and guided by the guide plate fitted in the elongate bar.

Abstract: The silencer according to the invention contains two chambers (10,11) separated by a partition wall (14) and includes also a guide plate (25) guiding cooling air from a fan (27) through a channel (26) in which recesses (23) from one chamber terminate. By means of an ejecting function, then being formed, exhaust gases are evacuated into the channel and mixed with the cooling air to a lower temperature.

Abstract: A marine engine (18) is provide with a multi section injection molded thermoplastic air box (24) directing air to the fuel system's air intake throat (22) and silencing engine noise emitted back through the throat. The air box has a cover section (28) and a base section (26) mounted to each other solely by a seal (30) along a peripheral seam around the entire perimeter thereof, to prevent fuel leaks. The housing sections are preassembled to each other prior to mounting to the air intake throat. A removeable plug (70) in the cover section allows access through the cover section to bolts (56, 58) mounting the base section to the throat. Access is also enabled to a fuel adjustment screw (74) to enable adjustment, with the air box fully assembled and mounted in place on the throat, to enable adjustment under actual operating conditions. Air guide passages (32, 34) and an air plenum chamber (36) are all molded in place.