Abstract: An element of a sound arresting device has a cylinder and a blade integrally formed in the cylinder and helically twisted along the longitudinal direction of the cylinder. A plurality of elements are coupled to each other along their longitudinal direction and are fitted in a pipe. The ends of the two adjacent blades are perpendicular to each other. The pipe is covered with a sound insulating material. The elements and the pipe are made of a porous metal material, a porous plastic material or a porous ceramic material. When the sound arresting device is used as an automobile muffler, acoustic waves propagating in the gas are repeatedly mixed, interfere with each other and are absorbed by the apertures and the sound insulating material, thereby decreasing noise from the engine. Dust in the exhaust gas is captured by the apertures of the elements and the pipe, and is removed from the exhaust gas.

Abstract: A muffler for internal combustion engines in which the structure cancels sound waves by interference. The gases generally flow in one direction through the muffler with intermittant flow reversal occurring only upon acceleration. The muffler is formed with a plurality of longitudinal chambers divided by reflection walls. Edge echo openings in the reflection walls permit limited gas entry into the chambers. A plurality of helical members surrounded by a large open tube and pierced by a small open tube channel all of the gases through a bulkhead wall which divides the muffler housing into two volumetrically generally equal portions.

Abstract: Means for accelerating the discharge of exhaust gas from an internal combustion engine, adapted to be mounted to the end of the engine exhaust pipe, in which exhaust gas from the engine is swirlingly guided by a plurality of spiral blades disposed in a tubular member, to form a super low pressure space at the center of the exhaust gas flow, thereby to accelerate the discharge of the exhaust gas.

Abstract: A muffler for automobile internal combustion engines consisting briefly of a housing having an inlet end where the exhaust gases are channeled through a tubular member having a helical member so that the gases are forced into a spiral flow pattern. The helical member extends beyond the end of the tubular member so that the gases are then permitted to follow a larger spiral pattern where they reflect against the walls of the housing. The housing has an outlet opening which is smaller than the housing diameter which causes compression of the gases and further reflection and interference of the sound waves. The muffler is formed with a counterflow reverberation chamber, a central chamber and a directional-flow reverberation chamber.

Abstract: A porous acoustic element is disclosed having a configuration comprised of individual cross-wound porous layers of widely varying porosity, with transition plenum layers interposed therebetween having a configuration so as to prevent formation of blockages and small area openings which would be created by a direct overlay winding of differing pitch. The porosity of each wound layer increases in successive layers to compensate for expansion of the gas as it flows through the element. The resulting porous element allows gaseous flow therethrough, with maximum pressure energy dissipation and controlled velocity to minimize aerodynamic noise created by flow through valves and other flow restrictions. A specific embodiment is disclosed in which the porous layers are created by variable pitch wire ribbon cross windings and the transition layers are provided by wire mesh having relatively large openings.

Abstract: This invention is directed to an apparatus and method for treating a flowing gas so as to decrease the back pressure of the flowing gas and the noise of the flowing gas.

Abstract: A silencer construction for connection to the intake side of a compressor comprises an assembly of axially spaced annular sound damping elements which form air in-flow passages therebetween. The sound damping assembly is located in a radially outer annular chamber of the silencer housing and the radially inner circumference of each of the sound damping elements merges into a curvilinear air guiding element which functions to deflect the partial air flows leaving the passages between the damping elements in the direction of the main air flow into a convergent intake manifold of the compressor.

Abstract: The acoustic silencer functions as a pulsation dampener to minimize noise generated in liquid and/or gaseous fluids inherently present in fluid conveying systems which embody pumps, compressors, engines and the like. The device includes a shell divided into first and second compartments by a partition supporting a central tube placing the compartments in communication with each other. The tube passage itself is provided with internal diametrically oppositely positioned vanes forming an acute angle with the axis of the tube to impart a rotational component to fluid flow through the tube. A polar or rotational inertence is thus provided in addition to linear inertence to the fluid flow thereby enabling shorter tubes to be utilized with a subsequent simplication in the manufacture and an increased reliability in the structural integrity of the silencer.

Abstract: A muffler assembly for substantially dampening acoustical vibrations of engine exhaust gases. The muffler assembly includes flow control means, such as a diffuser having a centrally disposed baffle with radially extending deflector vanes having axially extending tabs. The diffuser can be positioned in a tubular expansion joint which is secured to an apertured louver tube within a loosely compact shell of sound attenuating material. The diffuser substantially blocks and restricts the axial flow of exhaust gases along portions of the longitudinal axis of the louver tube, deflects the flow of exhaust gases toward the sound attenuating material and creates turbulent flow.

Abstract: An exhaust apparatus for internal combustion engines comprises an outer pipe having an enlarged intermediate portion and at least one end portion having nearly the same diameter as the exhaust pipe from the engine for connection thereto, an inner pipe of approximately the same diameter as the exhaust pipe, a plurality of helical passages provided between the inner and outer pipes and sets of fins arranged inside the inner pipe at each end to impart vortical flow of gases passing through the inner pipe and to accelerate the gases through the helical passages and absorb them from the engine, the end portion of the outer pipe being connected with the exhaust pipe by means of an encircling clamping ring.