Abstract: A low puff boom microphone includes a protective grid covering an end portion of the microphone housing, a microphone capsule near the protective grid, a layer of material between the protective grid and microphone capsule, a spacer between the layer of material, and an open area laterally of the spacer.

Abstract: An adjustable motorcycle muffler affixable to the exhaust pipe of a motorcycle. The muffler includes a stationary ring which is affixed to the exit end of the muffler body and the stationary ring has several openings therethrough. An adjustable ring is affixed to the face of the stationary ring and is movable to increase or decrease the gas flow resistance through the stationary ring.

Abstract: A universal muffler construction (10) comprising: a muffler housing member (11), housing end plate members (12), a primary exhaust tube array (13), a baffle locator plate element (15), an auxiliary exhaust tubing array (16), and, auxiliary end plate elements (17) which are orientable with respect to one another to produce a variety of different internal muffler flow path configurations.

Abstract: A tuneable exhaust pipe for an internal combustion engine having a baffle slidable longitudinally within the exhaust pipe at the upstream end a plug in the downstream end. The baffle and plug each have an opening for passage of exhaust gasses therethrough. The baffle defines a resonate chamber on each side of it. The chambers avoid turbulence and maintain the shock wave in the gasses so that the chambers cause an additive dynamic relationship calculated to cause a supercharging effect on the engine by increasing the internal pressures therein.

Abstract: A universal heat shield which may be varied in length and shape to fit a variety of mufflers, catalytic converters, and the like, is disclosed. A pair of metal sheets, each of which includes a pair of planar members intersecting at a crease line, a pair of slots and a pair of tabs, are fastened to each other with screws which extend through the slots. The shield is fastened to the muffler by strapping the tabs to opposite ends of the muffler body.

Abstract: A fluid operated vacuum device for manipulating a workpiece includes a rectangularly shaped metal body having a plurality of fluid passageways therein. One passageway communicates with a suction cup for creating a vacuum between the cup and the workpiece. Another fluid passageway terminates in an exhaust opening on one end of the body over which there is secured a plastic muffler for dispersing and silencing fluid exiting from the body. The muffler is substantially hollow and includes a plurality of openings in one side thereof through which exhaust fluid may escape into the ambient atmosphere. The effectiveness of the muffler is increased by a recess in the body circumscribing the exhaust opening, a perforated baffle member within the muffler, and a series of dimples in an interior wall of the muffler upon which exhaust fluid impinges.

Abstract: A muffler for use with pneumatically powered apparatus has a cylindrical housing with air outlet slots, to the back of which there is a pipe-like damper cartridge. Within the cartridge there is an axially adjustable choke body whose choke head is guided with a sliding fit by radial nosepieces resting against a support sleeve for the damper cartridge. A coned air flow controlling part of the choke head is used together with a coned face of the inner end of a connection inlet hole of the housing for forming an adjustable choke gap.

Abstract: An acoustic lining for a flow duct has a first perforate skin fixed to an underlying sound-absorbing layer. The first perforate skin is overlain by a second perforate skin which forms the wall of the flow duct. One of the skins is relatively moveable in a sliding sense with respect to the other skin so as to vary the acoustic impedance of the duct wall as the perforations in the respective skins slide into and out of registration with each other. This enables the acoustic impedance of the duct wall to be varied to suit the flow and noise conditions prevailing in the duct and so obtain optimum noise attenuation in the duct, which may be the intake duct of a turbofan aeroengine.

Abstract: A sleeve is slidable longitudinally of a can, on a weapon, containing sound suppressing means, between a first position retracted onto the can and a second position extending forwardly from the can with only adjacent ends lapping, to enhance sound suppressing action when the sleeve is moved to the second extended position. A longitudinally extending slot in the sleeve, with laterally extending notches, and a stop disposed in the slot to limit movement of the sleeve on the can. A knob with lock means to secure the stop in a selected notch of the slot.

Abstract: A sound suppression system having a sound suppression chamber formed from a longitudinally extending tubular housing. One end of the tubular housing is closed by an end plug which has a bore through which passes one end of a tubular member. The tubular member comprises a gun barrel having a cylindrical sleeve surrounding a predetermined length of the gun barrel. The tubular member has a plurality of tubular passages each of which have their one end in communication with the bore of the gun barrel and their other end longitudinally displaced therefrom adjacent the end of the gun barrel to place them in communication with the interior of the sound suppression chamber. A baffle having a cylindrical body approximating the interior diameter of the tubular housing is positioned within the tubular housing. Both the interior of the tubular housing and the outer cylindrical housing of the baffle are threaded so that the baffle may be adjustably positioned through the length of the tubular housing.

Abstract: A silencer for an internal combustion engine includes a main silencer having an axially movable tubular member located therein which is movable from a first position in which it constitutes an extension of an inlet to the main silencer and a second position in which it is spaced from the inlet for exhaust gases entering the silencer, thus permitting the exhaust gases to flow directly into the main silencer.

Abstract: Silencers for gas discharge devices employing easily replaceable cartridges utilizing juxtapositioned layers of wire mesh and porous absorbed material which dissipate exhaust noises of an exhaust system and deflect under pressure of the exhaust gases to provide a self cleaning function.

Abstract: An exhaust device is provided comprising a first diverging portion extending into a cylindrical envelope into which is axially displaceably mounted a streamlined conically shaped member adapted to be moved in relationship to the engine rating.

Abstract: To assist textile mills in complying with Government regulation of noise levels, a tunable noise suppression device or muffler is connected to the exhaust of the fiber collection box of a pneumatic spun fiber collection system of a spinning machine. The device is adjustable to reduce exhaust noise to an acceptable level while maintaining the necessary degree of suction in the fiber collection system. The noise suppression device has the ability to nullify the most predominant noise generating sound wave lengths and/or predominant noise frequencies through tuning, whereby it is unnecessary to construct various sizes and configurations of the suppression device for use on different textile machines which may possess differing predominant noise frequencies.

Abstract: A two-piece outer casing encloses a volume with a central divider plate which extends the length of the casing. The two portions of the casing are bolted or otherwise clamped about the divider plate. Each half of the outer casing has angled inner ribs or diverters. The diverters in one casing extend at an opposite angle to the longitudinal axis of the central plate as do the diverters of the other outer casing. The inner edges of the diverter seal against the surface of the central plate. The transverse dimension of the central plate is less than the transverse dimension of the diverters and the outer casing such that an exchange aperture is defined between the central plate and the inner surface of the outer casing between adjacent pairs of diverters. The casing has an exhaust input port and an exhaust outlet port at opposite ends and opposite sides.

Abstract: The application discloses a new silencer for internal combustion engines. This silencer comprises an internal resilient tube capable to vibrate longitudinally and permeable to the exhaust gas and an external sheath. An end piece closes the internal tube. Spacers are secured to the internal tube and another end piece provided with apertures is secured to the end of the external sheath. The exhaust gases exit from the internal tube through the space comprised between the spacers and the external sheath towards said apertures in the other end piece.