Abstract: An air distribution system for electronic components utilizes an air supply unit with a silencer unit. The silencer unit attenuates sound associated with the air unit blowers with inlet and discharge silencers. The blowers have check valves which provide for isolating each blower for continued operation even with one blower. The cooling air is transported to a circuit board module stack from the blowers through ducts and a bank of rod valves. The valves allow maximum air flow to the modules with minimum resistance. The ducts have a flexible portion which have quick disconnects and act to isolate the modules from vibrations and static. The modules utilize channels in an air plate with different sized baffles to provide even distribution of cooling air to the printed circuit boards.

Abstract: In an automobile, a silencer connected to an exhaust pipe includes a casing made of thermally resistant synthetic resin and provided at an inner surface with a thermally insulating material. The silencer is disposed between a side frame and a side body and covered with an undercover from below the silencer and is disposed between a side frame and a side body of an automatic vehicle in a space behind a rear wheel.

Abstract: The cylindrical enclosure 12 of a recuperator 10 as in FIG. 2 contains an annular coaxial heat exchanger 50 full of cooling liquid 22 circulating therethrough. Exhaust gas from an internal combustion engine flows from an inlet end 32 through the heat exchanger 50, first in an axial region 15 via a conduit 14, then back through a surrounding annular region 18, then through tubes 37 to an outlet end 34. The inlet 30 and outlet 31 for the gas are in the side wall 40 of the cylindrical body 12, and the exhaust gas 11 enters and leaves via conduits 14 and 19 that are perpendicular to the side wall 40 at the inlet 30 and at the outlet 31. So the ends 41 and 42 of the body 12 are free of adjacent obstruction, and at least one of them is removable, as in FIG. 4 or FIG. 5 . Thus, the recuperator 10 can be opened and closed to make the interior accessible for inspection, cleaning, or other desired purpose.

Abstract: The vehicular muffler assembly of this invention includes a muffler which has a elongated shell. An inlet communicates with the interior of the shell to provide a port for entry of exhaust gases from an internal combustion engine to the interior of the shell. An outlet communicates with the interior of the shell to allow exhaust gases to leave the shell. A heat shield is mounted on the exterior of the shell. The heat shield is symmetrical and has an outer wall. The outer wall has a weld skirt which is integral with the outer wall. A plurality of discreet welds spaced along the weld skirt fixes the outer wall to the shell. A slot opening is formed in the weld skirt between adjacent discreet welds.

Abstract: An exhaust muffler and heat shield assembly and a method for producing the assembly are provided The muffler includes a pair of stamp formed external shells. At least one external shell is stamped to include a plurality of tabs extending outwardly from the peripheral flange of the external shell. The tabs preferably are disposed at locations that otherwise would have defined wastage to be trimmed from the stamp formed external shell The heat shield is configured to be mounted to the muffler by crimping the tabs. In particular, peripheral regions of the heat shield may be engaged between the peripheral flange of the muffler and the crimped tabs. Alternatively, the heat shield may include slots through which the tabs extend for mechanical engagement with the heat shield.

Abstract: A lawn mower having a driver's seat mounted on a vehicle body, an engine mounted rearwardly of the driver's seat, a radiator and a radiator fan disposed between the driver's seat and engine, an engine hood for covering the engine and radiator, and a muffler disposed in a space defined by an upper rear surface of the engine and the engine hood. The hood includes a rear wall defining an exhaust grille, and the muffler has an exhaust outlet opening in a direction along cooling air flows from the radiator fan to the exhaust grille. The cooling air flowing rearwardly by action of the radiator fan passes through the radiator and flows out rearwardly of the vehicle body, carrying heat from upper positions of the engine and heat radiating from the muffler. The muffler releases exhaust gas to be entrained by the cooling air flows.

Abstract: A construction element for a noise-suppression shed of the type used for ground-testing jet engine aircraft. These sheds usually have transversely extending continuous apertures for the admission of fresh air, the inner face of the shed's roof being provided with spaced liners of a sound-absorbing material defining flowpaths for fresh air entering the interior of the shed. The element comprises a cover panel element carried by a mounting structure and having a stepped profile configuration in the longitudinal direction of the shed, and mutually spaced first and second elements of a sound-absorbing material. The arrangement of a plurality of construction elements in rows extending in the longitudinal and transverse directions and interconnection of the respective mounting structures results in the formation of continuous air inlet gaps extending over the full width of the roof and passing between the sound-absorbing liners.

Abstract: A heat shield (1) includes a support layer (2) that is perforate only in predetermined partial areas (6, 7, 8) and comprises an insulation layer (3) that has a protective coating (4, 5) on both sides thereof. In particular, flange areas (6), attachment areas (8), and areas of bent or angular deformities (7) are free of perforations. A protective coating (5) on a side of the insulation layer facing the support layer has a thickness of less than 30 .mu.m and can be constructed of a thin aluminum foil or a sprayed or deposited metalized coating. Preferably, the protective coating has fine pores.

Abstract: A vertical exhaust pipe having an inner pipe with an upper opening. An outer pipe is positioned around the inner pipe and has an end portion that extends beyond the upper opening in the inner pipe, said end portion defining an outlet through which exhaust gas exits the outer pipe. A mechanism is coupled with the inner pipe for blocking rain that has entered the outer pipe from falling through the opening in the inner pipe. A ledge mechanism is positioned beneath the upper opening in the inner pipe and between the inner and outer pipes for forming a chamber within which is held rainwater that has entered the outer pipe. A drainage mechanism allows rainwater in the chamber to pass to the exterior of the outer pipe.

Abstract: A discharge silencing apparatus having a noise abating device, a housing enclosure for the device and an integral frame for supporting a blower and accompanying motor. The frame provides support for the blower and provides sealing ends for the enclosure to insure outflow of air through the noise abating device to an outlet of the enclosure.

Abstract: The invention relates to a combination power and heat unit with a bedplate (1), flanged-together machines (2, 3), a noise suppressor (8), an exhaust-gas heat exchanger (9), a cooling-water heat exchanger (19) as well as the associated auxiliary apparatus and piping, wherein the bedplate (1) shelters the noise suppressor (8) and the exhaust-gas heat exchanger (9) along its opposite longitudinal sides below the machines (2, 3), which are elastically supported on the bedplate (1).

Abstract: An exhaust pipe shield for motorcycles or the like comprises curved shield member having a generally constant radius greater than that of a cylindrically shaped exhaust pipe. A plurality of spacer blocks are interposed between the shield inner surface and the outer surface of the exhaust pipe. The spacer blocks are secured to the shield. A clamping mechanism is coupled to the spacer blocks for securing the shield to the exhaust pipe.

Abstract: A heating device, particularly an automotive heating device, in which a noise muffling device is integrated within the heating device. The muffler can be provided in the combustion pipe defining the combustion chamber, or the combustion pipe, itself, can be designed as the muffler. The muffler operates by absorption and/or reflection sound muffling techniques in accordance with various embodiments, and may, simultaneously, purify the combustion gases, for example, by catalytic afterburning, and/or by filtering of soot particles. The muffler is arranged in a hot zone, but not in the flame area of the combustion chamber, to achieve a self-cleaning action. In other embodiments, noise muffling material is arranged in an exhaust gas collection chamber to achieve sound muffling based on reflection and/or absorption and/or other conventional sound reduction methods. In all cases, the need for an external muffler in the exhaust line from the heating device is eliminated.

Abstract: A power thermo-coupling unit with muffler (4, 5) and exhaust gas heat exchanger (6, 7) avoids the requirement of a disproportionately large space for component removal at the front end of the power thermo-coupling unit. The muffler (4, 5) and the exhaust gas heat exchanger (6, 7) each have two separate components, the lengths of which are shorter than the distances between the center column (8) and the end walls of the unit support (1).

Abstract: A fireplace provided with a sound reducer is shown. The sound reducer eliminates ambient noise feeding back to the indoor through the flue system of the fireplace.

Abstract: A muffler cover has a plurality of air holes formed therein. At least part of the air holes is formed in such a manner as to have configurations which indicate characters or symbols, and at least those portions of the muffler facing the portions of the muffler cover that correspond to the air holes indicating the characters or symbols are coated with a heat resistant coating.

Abstract: A reciprocating piston and cylinder pneumatic motor with a sound-reducing system that diffuses exhausting air by directing it across the curved outer surface of the cylinder.

Abstract: The liquid jet cutting machine contains at least one cutting head provided with an apparatus for producing high-pressure liquid at pressures in excess of 1000 bar. The cutting head delivers a high-pressure liquid cutting jet and is preferably movable or guideable along a predetermined cutting path. An apparatus is provided for holding the workpiece to be cut at least during the cutting operation. At least the high-pressure liquid producing apparatus, preferably inclusive of a drive and/or auxiliary aggregate, the cutting head, the holding apparatus and a cutting jet collector are connected with a common frame and form a positionally displaceable transport unit. The cutting head is preferably automatically controllable in its movements by a guiding apparatus which constitutes an industrial robot. The holding apparatus may also perform controllable movements and preferably contains an infeed and/or outfeed device for the workpiece to be cut, as well as a drain device for the spent jet liquid.

Abstract: A vehicular muffler heat shield comprises at least one and preferably two longitudinally rigid, transversely flexible shield members. The shield members have muffler shell contacting, longitudinal ribs and raised, perforated shield panels. The shield members are identical and longitudinally slidable to fit mufflers of a range of lengths. The shield members are strapped to muffler shells by separate, flexible straps which conform the shield members to muffler shell contours.

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 stacking device for sheet material such as banknotes and receipts has a stacker drum with a suction opening at a predetermined location on the periphery. The suction opening grips the leading edges of the sheets to be stacked at a first tangential position and releases the sheets against a stopper at a second tangential position. The stacker drum has air openings on the periphery behind the suction opening. The air openings discharge pulsating compressed air to separate the portion of the sheets trailing the leading edges from the drum.

Abstract: A heat recovery muffler comprising an outer body and having an annular heat exchanger disposed within the body and spaced from the ends thereof. The heat exchanger is provided with a central opening and an exhaust gas inlet pipe is located within the central opening and spaced inwardly therefrom to provide an annular passage. The downstream end of the central opening of the heat exchanger is closed off so that the flow of exhaust gas entering the muffler body through the inlet pipe will be reversed and is directed upstream. The heat exchanger is formed with a plurality of tubes that provide communication between opposite ends of the body, and the exhaust gases, after being reversed in flow, then flow downstream through the tubes in heat exchange relation with a cooling medium, such as water, to cool the exhaust gases and heat the cooling medium. The cooled exhaust gases are discharged to the atmosphere through an outlet pipe in the downstream end of the muffler body.

Abstract: An exhaust muffler cover for internal combustion engines having a piled buffering layer provided on the outer surface of a cover member surrounding the exhaust muffler body with a suitable gap therebetween. The cover member has a sufficiently reduced thickness to ensure a good radiation of the heat transmitted from the exhaust muffler body. An attaching member playing the role of a reinforcement is fixed to the inner peripheral end of the cover member.

Abstract: In bottle transporting apparatus, noise resulting from bottles colliding with each other and noise emitted by the transport mechanism is suppressed by moving the bottles in a water bath which immerses the mechanism and at least partially immerses the bottles so the sound is absorbed and attenuated by the water. Means are provided for partially filling the bottles with liquid before they reach locations where noise would be generated and this further suppresses noise. Water jets are used to assist bottle movement where the bottles are transported on conveyors and the jets may be used as the sole propulsion force in apparatus wherein the bottles are simply pushed along smooth support surfaces.

Abstract: A vibration damping device for a body resonant at two frequencies, is formed by a plate which can be connected to the body transversely with respect to its vibration direction. A post extends from the plate and mounts one end of an elastically flexible tongue which extends from the post substantially parallel to the plate so as to form a space between the tongue and plate. A weight is fixed to the other end of the tongue and vibration damping material is positioned in the space. The tongue and weight form a system resonant at both of the bodies' resonant frequencies, the tongue's energy being absorbed by the damping material.

Abstract: A system comprising a rail wheel and rail has the wheel and preferably also the rail provided with vibration dampers which absorb vibration having the frequency of the radial resonant vibration frequency of the wheel, for the purpose of preventing the formation of ripples in the rail head's surface on which the wheel runs.

Abstract: Noise attenuation during the purging of pipes by means of steam blowing is achieved by the use of a receptacle into which steam is blown upon discharge from one end of a pipe; a linkage pivotally suspends an exchangeable mouthpiece adjacent to a front end opening of the receptacle and carries a stop member; actuation of the linkage places the mouthpiece over a front end of the pipe adjacent to said opening while removing said stop and, alternatively, places the mouthpiece over a front end of the pipe adjacent to said opening while removing said stop and, alternatively, pivots the mouthpiece to clear the pipe while causing the stop member to be placed in front of that front end.

Abstract: An engine enclosure (10) has a noise suppression arrangement (15,15a,15b) mounted thereon including a plurality of acoustical energy absorbers (20,20a,20b) and sound reflectors (24,24a,24b) spaced from the absorbers to provide airflow passages (26,26a,26b) therebetween. The noise suppression arrangement (15,15a,15b) efficiently absorbs and reflects acoustical energy and exhibits a low space to sound absorption efficiency ratio in comparison to conventional noise suppression arrangements.

Abstract: A noise reducing assembly, including a sound absorbing grille (30) with louvers (33) and a sound and air diverting unit (40) is used for noise control in an earthmoving vehicle (20). The sound absorbing grille (30) has a perforated panel (32) covering an air exhaust opening (22). A plurality of sound absorbing louvers (33) are attached to the perforated panel (32) in spaced relationship. The sound and air diverting unit (40) is disposed in front of the sound absorbing grille (30), and includes means (42a,42b,42c) for diverting the sound and air from said sound absorbing grille (30) vertically and transversely of the vehicle body. The walls of the louvers (33) and the sound and air diverting unit (40) are filled with sound absorbing material (37,43).

Abstract: For suppression of flow-driven resonances, a cross section modification is undertaken at the outlet of a diffuser. The length of the cross section modification stands in a specified relationship to the sonic wave to be suppressed.

Abstract: A method and apparatus for reducing acoustic noise associated with the release of gases from a submerged device, such as a sea water battery. A flat piece of material, preferably polyurethane, is mounted onto the top of the device. The piece of material is provided with an outwardly extending lip on the lower surface thereof adjacent an outlet port through which the gases issue. The lower surface of the lip is preferably curved upwardly and outwardly away from the outlet port and is disposed immediately at the upper edge of the outlet port. Gas emitted from the outlet port immediately forms bubbles on the lower surface of the lip, and the bubbles so formed pass outwardly and upwardly along the lower surface and subsequently escape into the free water.

Abstract: Apparatus for attentuating noise emitted from an inlet port to a centrifugal fan comprises a panel member which is mounted in spaced confronting relationship to the inlet port and includes a rigid backing member, a facing mounted in spaced disposition from the rigid backing member, partitions dividing the space between the rigid backing member and the facing into a plurality of cavities, and acoustic infill in the cavities. The facing has a plurality of perforation zones, and is formed in each perforation zone with small perforations whereby the facing is rendered acoustically permeable over a limited area only. One wall of each cavity includes a perforation zone of the facing, whereby the cavities constitute Helmholtz absorption cavities. The facing is adapted to face the inlet port and transmit noise for attenuation in the cavities.

Abstract: A muffler system positioned within the engine housing of the vehicle such as a garden tractor, includes a muffler surrounded by an open ended tubular heat shield having a venturi tube on its outer end which receives and accelerates the exhaust gases to create a flow of cooling air through the engine housing and between the muffler and the tubular heat shield for extracting heat from both the engine housing and the muffler.

Abstract: A centrifugal fan is treated acoustically by the provision of tuned noise absorption cavities preferably including absorbent infill between an acoustically permeable scroll and casing of the fan. Alternatively, or in addition an acoustically absorbent panel structure is provided in spaced confronting relationship with the inlet port of the fan. The panel structure has an acoustically permeable facing spaced from a rigid backing and the space may be divided into noise absorption cavities and specifically Helmholtz type absorption cavities, the absorption bands of which are broadened by including acoustic infill. It is most advantageous to provide a multiplicity of Helmholtz absorption cavities tuned to respective different center frequencies of their acoustic absorption bands.

Abstract: A power unit including a liquid-cooled engine, a radiator in fluid communication with the engine for cooling engine coolant, a fan on one side of the radiator for directing air therethrough, and a noise suppressing baffle on the other side of the radiator for altering the path of travel of air exiting the radiator and absorbing fan noise including a housing containing, noise suppressing material. The housing includes the improvement wherein a perforated panel faces the side of the radiator opposite the fan and is slightly spaced therefrom with the panel being pyramid-shaped and extending toward the radiator and presenting at least three generally planar surfaces intersecting at a common point to the radiator.

Abstract: A noise silencer covering an air discharge opening in front of a radiator is used for noise control for an earthmoving vehicle. The silencer encloses a radiator grill which is removably attached to a forward end of an engine enclosure. The noise silencer is provided with upper and lower discharge openings with the open area of the upper opening being larger than that of the lower opening. The walls of the silencer are lined with sound absorbing materials.

Abstract: A noise reduction device for use with an impact tool which comprises a deformable block having a flat face and an opening therein for accepting the set of the tool, and a cylindrical housing extending from the block and sealed about the tool, with an open conduit extending from said housing.

Abstract: A helical cutterhead for a wood planer for reducing noise level during planing by supressing vibration and sound radiation by having more than one knife blade engaged in the workpiece at any instant by satisfying the minimum condition of the formula L=.pi.D cot.phi./N is less than the workpiece width and in which L is the contact distance, D is the cutterhead diameter, N is the number of knife blades, and .phi. is the helix angle, and in which L is less than 4 inches.

Abstract: A tuned pipe exhaust for a two cycle internal combustion engine for snowmobiles and the like includes a conically shaped converging megaphone section terminating in a small end tube. An absorptive spiral muffler unit is co-axially secured to the end tube and includes an inner radial end wall extending radially from the end tube. The muffler unit attenuates high frequency exhaust noise. The space between such end wall and the upstream conical wall of the tuned pipe is enclosed with a tubular resonator wall to define a resonator cavity with coupling opening in the end tube. The cavity and throat opening defines a Helmholtz resonator which attenuates low frequency exhaust noise. The combination of a low frequency reactive section and a high frequency absorptive section creates an effective balanced silencer operating over the normal frequency spectrum of such engines.