摘要:
Disclosed herein is a sound wave control device which is shaped in a lens form or a prism form from an acoustically rigid porous material, wherein numerous paths having different path lengths are provided and the apparent medium density is varied. This second wave control device is used to improve the sound quality and the directivity of the sound waves from a speaker and the directional control of noises.
摘要:
A perlite sound absorbing plate and a sound insulating wall constructed by arranging a number of said plates side by side and by assembling together into one integral body are disclosed. The plate is composed of a mixture including 1,000 cm.sup.3 by bulk volume of formed perlite particles each having a diameter of 0.1 to 7.0 mm, 100 to 140 g of cement, liquid rubber latex containing 5 to 20 g of solid ingredients and a suitable amount of water and produced by press molding with a compression ratio of 1.10 to 1.30. The wall is constructed by assembling a number of said plates each provided with a side groove with the aid of supporting columns and reinforcing plates, each having a ridge adapted to be engaged with the side groove of said plate.
摘要:
A vibration isolating device comprises a base, a plurality of support members each placed onto the base and comprised of a two series layer of an electroviscous body and an elastomeric body, and a cradle supported through these support members. These support members are provided with circuit for applying voltage to each electroviscous body, respectively.
摘要:
A vibration damping apparatus for transportation includes a vertical direction damping device having air springs and air dampers arranged in parallel on a base and horizontal direction damping device having laminated rubbers. The vertical and horizontal damping devices are combined in series for supporting a load base. The apparatus further includes an air supply source for supplying air into the air springs, control valves provided between the air springs and the air supply source for controlling air supply into and exhaust from the air springs, displacement detecting device for detecting displacements of the load base relative to the bases, and control device for controlling the control valves on the basis of results detected by the displacement detecting device to maintain the load base horizontally and at a constant level relative to the base whatever load is loaded on the load base.
摘要:
A vibration free container for transportation comprises vibration isolating device which are arranged under the container and comprises a lower layer and an upper layer. The lower layer consists of at least two long laminated rubber bodies in the form of a parallelepiped extending in parallel with each other and upper layer consists of a plurality of column-shaped vibration isolators fixed between a bottom plate of the container and upper surfaces of the lamianted rubber bodies. Each of the laminated rubber bodies comprises rubber layers and metal plates alternately laminated. In another aspect the vibration free container comprises an outer casing and an inner casing received in the outer casing, and the vibration insulating device is interposed between the outer and inner casing to support the inner casing relative to the outer casing.
摘要:
A noise reducing apparatus in the form of a hollow body comprising two or more passage groups consisting of a plurality of passages. The length of each passage is determined such that the sound waves emitted from the passages of the adjacent passage groups form plane waves which are shifted by a half wavelength so that plane waves interfere each other. The apparatus can be secured to an opening of construction and reduce the level of sound pressure from a sound source without any closed shield construction surrounding the sound source.
摘要:
A device for controlling a propagation direction of noise, which is preferably associated with a sound insulating wall to significantly improve its sound reducing effect of alleviating noise emitted from a noise source such as a railroad, highway and the like on which an electric car and automobiles run. The device comprises a hollow structural body composed of a plurality of elongated vertical hollow passages arranged at right angles to a substrate and spaced apart from each other by means of partition walls. The upper noise inlet side surface of the hollow passages face a propagation direction of noise emitted from the noise source and serve to refract and lag in phase the noise passed therethrough, thereby producing a sound reducing region located intermediate between a direct sound propagation and the refracted sound propagation. In one embodiment, a pair of hollow structural bodies are arranged in opposition to each other to form an arch type device. In another embodiment, the hollow structural body may be provided at its noise inlet or outlet side surface with an extension of the hollow passages.
摘要:
A sound absorbing body which can effectively be utilized as an exterior sound absorbing wall or an interior wall of a house is disclosed. The sound absorbing body comprises a number of sound absorbing cavities inclined at an angle .alpha. which is smaller than 80.degree. with respect to a transverse horizontal sectional plane of the body, the sound absorbing cavities being opened at the sound incident surface.
摘要:
Curable coating compositions particularly suitable as a vehicle for printing inks, comprising a resin obtained by esterifying with acrylic or methacrylic acid a hydroxyl group-containing resin prepared either by reacting ingredients (A) and (B) to form a reaction mixture which is then reacted with ingredient (C) or by reacting the ingredients (A), (B) and (C). The ingredient (A) is a five-membered cyclic compound having conjugated double bonds or a Diels-Alder's reaction product thereof, the ingredient (B) a compound having both a polymerizable double bond and a hydroxyl group in the molecule and (C) a resol type phenolic resin.
摘要:
A device for controlling a propagation direction of noise which is preferably associated with a sound insulating wall to significantly improve its sound reducing effect of alleviating noise emitted from a noise source such as a railroad, highway and the like on which an electric car and automobiles run. The device comprises a hollow structural body composed of a plurality of elongate hollow passages superimposed one upon the other and spaced apart from each other. The passages are arranged in a propagation direction of noise emitted from the noise source and serve to refract and lag in phase the noise passed therethrough, thereby producing a sound reducing region located intermediate between a direct propagation sound and the refraction propagation sound.