Abstract: The present invention provides an accelerated weight drop for use as a seismic energy source, a method for operating an accelerated weight drop for use as a seismic energy source, and a seismic survey system including the accelerated weight drop. The accelerated weight drop, among other elements, includes a strike plate positionable on a surface, and a striker positionable over the strike plate. The accelerated weight drop further includes a compressed gas spring configured to drive the striker toward the strike plate thus creating seismic waves within the surface, wherein the striker is slidably coupled to the compressed gas spring and the striker and the compressed gas spring rotatably coupled to the strike plate about an axis.

Abstract: The present invention provides an exhaust chamber system, comprising a stationary propeller type blade assembly with a nose cone within or adjacent to an expansion chamber, to create a vortex that swirls exhaust gas towards the outlet. The resultant vacuum within the exhaust chamber aids in scavenging an internal combustion engines exhaust gases, and in reducing system back pressure The exhaust chamber maintains the sound level of the exhaust within acceptable limits, while delivering improved horsepower, torque, and/or fuel efficiency over standard and other performance mufflers.

Abstract: A marine seismic source method capable of retaining low frequencies is disclosed. One embodiment of the method comprises a seismic source that generates an up-going wave and first down-going wave with opposite polarity. The up-going wave reflects off the ocean surface as a second down-going wave having the same polarity as the first down-going wave and the first and second down-going waves combine substantially in-phase to form a third down-going wave. A source apparatus to accomplish the method is also disclosed. One source apparatus embodiment comprises a device wherein at least part of the device is below the surface of the water and the device is adapted to cause oscillations below the surface of the water, and means for oscillating the device in the water to create an up-going wave and a first down-going wave and the up-going wave has reverse polarity relative to the first down-going wave.

Abstract: To provide a muffler device capable of improving the discharge of exhaust gas, while discharging the exhaust gas in any desired direction. The muffler device is connected to a rear end portion of an exhaust pipe extending from an internal combustion engine of a vehicle. An exhaust outlet opening is provided that opens outwardly and laterally of the vehicle and is disposed at a rear portion of a muffler main body. The muffler main body is provided with a muffler side cover and an end cap as muffler covers. The muffler side cover includes a slit. The slit serves as an air intake guide shaped portion for guiding ambient air so that the ambient air crosses the exhaust outlet.

Abstract: An acoustical panel comprising a continuous phase of an interlocking set gypsum matrix and a method of preparing an acoustical panel are disclosed.

Abstract: A sound attenuating cover is adapted for intimate fitment to a compressor of a domestic air conditioner, and comprises an outer sleeve member and a generally circular top member which is releasably secured to the outer sleeve member. Hook and loop fasteners secure a first end of the outer sleeve member to a portion of the outer periphery of the sleeve member. When the closure member secures the top member to the outer sleeve member, and the hook and loop fasteners are secured, a cylindrical cover having a closed top end is formed having a diameter adapted for intimate fitment to a compressor of a domestic air conditioner. Each of the outer sleeve member and the circular top member comprises inner and outer cover sheeting material, and at least one layer of sound attenuating material which is typically glass fiber together with barium loaded vinyl.

Abstract: An exhaust gas muffler is provided for an internal combustion engine, especially for an internal combustion engine in a manually-guided implement such as a power saw, a cut-off machine, or the like. The muffler has a housing having an inlet for exhaust gases and an outlet out of the housing. To achieve an after burning of exhaust gas in a straightforward manner, the exhaust gases in the housing flow through a reaction zone in which the exhaust gases circulate at least partially.

Abstract: A control system (10) controls a variable acoustical damping device (20) disposed in a sound producing channel (5) of a vehicle engine (1). The control system includes a controller (12) and a selection device (14). The controller is coupled to the variable acoustical damping device and stores a plurality of control patterns (A. B) for different levels of acoustical damping of the acoustical damping device. The selection device outputs a selection signal to the controller so that the controller controls the variable acoustical damping device based on one of the control patterns corresponding to the selection signal.

Abstract: A piston is reciprocated axially at high speed at very small amplitude by an actuator in the larger-diameter base of an acoustic resonator. According to pressure fluctuation in the acoustic resonator involved by reciprocal motion of the piston, fluid is sucked into and discharged from the acoustic resonator via a valve device at the top end of the acoustic resonator. The acoustic resonator is contained in a gas guide. Fluid from the valve device is introduced into the gas guide to cool the valve device.

Abstract: Methods and apparatus are provided for an exhaust duct having an externally replaceable acoustic liner. The exhaust duct includes a forward section that is configured to be axially coupled with a bulkhead collar on the aircraft, a body section that is coupled to the forward section and a stinger cap that includes the replaceable acoustic liner. The replaceable acoustic liner is configured to be slideably received by the body section.

Abstract: The present invention provides a resonator for attenuating acoustic vibration from an air intake passage. The resonator includes a neck, a resonator chamber, a piston-type member, and an actuator. The neck is attached between the air passage and the resonator chamber. The neck has two overlapping portions allowing the neck to extend within the resonator chamber. The piston-type member is located within the resonator chamber and is translated by the actuator to change the volume of the resonator and the neck length. By changing the volume and neck length of the resonator, the frequency attenuated by the resonator can be adjusted.

Abstract: A cooled acoustic liner useful in a fluid handling duct includes a resonator chamber 52 with a neck 56, a face sheet 86, and a coolant plenum 80 residing between the face sheet and the chamber. Coolant bypasses the resonator chamber, rather than flowing through it, resulting in better acoustic admittance than in liners in which coolant flows through the resonator chamber and neck. In one embodiment, the liner also includes a graze shield 88. Openings 40, 38 penetrate both the face sheet and the shield to establish a relatively low face sheet porosity and a relatively high shield porosity. The shielded embodiment of the invention helps prevent a loss of acoustic admittance due to fluid grazing past the liner. Another embodiment that is not necessarily cooled, includes the resonator chamber, low porosity face sheet and high porosity shield, but no coolant plenum for bypassing coolant around the resonator chamber.

Abstract: To provide a motorcycle exhaust system, which is less susceptible to the elevated temperature of the exhaust gases and vibrations induced by the motorcycle combustion engine (E) and in which the sectional area of the exhaust passage can be properly adjusted independence on the operating condition of the motorcycle combustion engine (E), the motorcycle exhaust system includes a motorcycle combustion engine (E) mounted at a location generally intermediate between front and rear wheels (3 and 9), an exhaust passage fluidly connected at one end with an exhaust port of the motorcycle combustion engine (E), a silencer (17) fluidly connected with the opposite end of the exhaust passage and supported by the motorcycle frame structure (FR) at a location generally above the rear wheel (9); and an exhaust control valve (24) disposed in an inlet of the silencer (17) for variably adjusting the sectional area of the exhaust passage.

Abstract: An ultra light, noise reducing composite (1) comprises an acoustically transparent, light weight film (6) between an underlay layer (5) and an air flow resistance layer (4). This composite allows to easily tune the acoustic properties by balancing the absorption and sound transmission behaviour of the composite (1). This air flow resistance layer (4) has an air flow resistance of between 500 Ns/m3 and 10,000 Ns/m3 and an area mass between 200 g/m2 and 3,000 g/m2. The underlay layer (5) has a stiffness value in the range between 100 Pa and 100,000 Pa. The light weight film (6) may consist of a synthetic foil and preferably has a thickness of 0.01 mm.

Abstract: To provide an exhaust device for enhancing the appearance quality, secure the degree of freedom in designing and enhance the cooling performance. An exhaust device in which a second exhaust muffler at a rear portion of an exhaust system extends rearwardly from an engine is disposed in a rear portion of a rear cowl wherein a rear end surface of the second exhaust muffler is covered with a resin-made muffler rear cover.

Abstract: An electro-acoustic transducer includes a tone generator, a vibrator, and a case. The tone generator includes a diaphragm, and a voice coil joined to the diaphragm. The vibrator includes a magnetic circuit having a magnetic gap at which the voice coil is positioned, and a suspension made of metal and having a first end joined to the magnetic circuit to suspend the magnetic circuit for allowing the magnetic circuit to vibrate. The case is joined to a periphery of the diaphragm, and includes a metal plate joined to a second end of the suspension. The metal plate is joined to the suspensions reliably, hence allowing the electro-acoustic transducer to be manufactured stably.

Abstract: The invention concerns a suction muffler for a hermetic refrigerant compressor with a housing having an inlet and an outlet and limiting at least one muffling chamber, and a gas supply channel located in the muffling chamber between the inlet and the outlet. It is endeavoured to prevent too much oil from remaining in the refrigerant gas flow. For this purpose, the gas supply channel forms a throttling path and ends in the muffling chamber, and that in the area of the inlet of the gas supply channel an oil extraction opening is located, which ends in the muffling chamber.

Abstract: A stethoscope cover incorporated into an isolation garment which cover operably retains the stethoscope listening device and at least a portion of the stethoscope sound tube so that a doctor or nurse can put on an isolation garment and use their preferred stethoscope to examine a patient because the portions of the stethoscope which come in contact with a patient or are near the patient are protected from coming directly in contact with the patient by the stethoscope cover.

Abstract: The exhaust created from the operation of pneumatic tools can create a considerable amount of noise. The present disclosure includes a detachable muffler apparatus used to reduce the sound during the operation of a pneumatic tool. The muffler apparatus includes a flexible outer housing that defines a muffler passage extending between a muffler inlet and a muffler outlet. The flexible outer housing includes an attachment end that defines the muffler inlet and a distal end that defines the muffler outlet. The attachment end can be removably attached to a pneumatic tool body by a fastener. Tool exhaust is forced through and around folds within at least one sheet of permeable material positioned within the muffler passage.

Abstract: A downhole tool for gathering formation data from inside a borehole includes a substantially tubular housing adapted for axial connection to a drill string and multiple sensors coupled to the tubular housing. The sensors include a first pair of sensors aligned along a first axis and adapted to measure a spatial derivative along the first axis, a second pair of sensors aligned along a second axis and adapted to measure a spatial derivative along the second axis, and a third pair of sensors aligned along a third axis and adapted to measure a spatial derivative along the third axis. In selected embodiments, the spatial derivatives are used to differentiate seismic or sonic compression and shear waves measured in a downhole environment.