Abstract: To provide a speaker unit capable of being thinned much further. A speaker unit 1 includes a voice coil 6 through which an input signal is passed, a voice coil bobbin 5 for converting the input signal flowing through the voice coil 6 into a mechanical reciprocating movement, a diaphragm 2 connected to either one side of said voice coil bobbin 5 in the reciprocating vibration direction; and a damper not connected to the voice coil bobbin 5 and connected to an outer edge portion of the diaphragm 2 and suppressing a rolling phenomenon of the voice coil bobbin 5.

Abstract: A nondirectional acoustic generator includes two acoustic generator units which are disposed facing each other as near as possible to the extent that diaphragms thereof do not become in contact with each other, drive units of the acoustic generator units being connected in series or in parallel to drive the acoustic generator units in phase and generate air compression sound waves which are radiated in the circumferential direction of the diaphragms.A speaker system includes a plurality of nondirectional acoustic generators coaxially disposed so as to align the centers of respective diaphragms and make the phases at sound generating areas coincident with each other.

Abstract: A speaker cone plate is provided with an inorganic surfacial hard layer formed at least on a face of a metal substrate and is subjected to a reinforcing treatment by hot isostatic pressing, wherein the surfacial hard layer may be composed of a carbide, an oxide, a borie or a phosphide or may be formed by plasma thermal spraying of an inorganic substance containing silicon nitride whiskers or silicon carbide whiskers.

Abstract: A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atomosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

Abstract: A method of forming diamond-like carbon layer which is advantageously adaptable as a coating layer on acoustic diaphragms. In the method, carbon vaporized out of solid carbon source is deposited onto the surface of the diaphragm as the coating layer in the atmosphere of catalystic gas, for instance, H.sub.2 +Ar or H.sub.2 of about 10.sup.-4 Torr. The deposited carbon layer on the surface of the diaphragm is an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond and crystalline carbon particles of hybridized orbital SP.sup.3 bond dispersed in the amorphous carbon, or an amorphous carbon of inclusion of hybridized orbital SP.sup.2 bond and hybridized orbital SP.sup.3 bond.

Abstract: Slurry consisting of water and solid material is fed to a plurality of supply chambers arranged in parallel to each other by a low pressure slurry pump, and the filled slurry is transferred to a transferring pipe under liquid pressure of a high pressure driving liquid pump. Also, to the upper and lower portions of the supply chambers are connected driving liquid supply/discharge pipes and slurry supply/discharge pipes having valves. The valves are selectively opened/closed in accordance with a detection of a float position within each supply chamber to thereby feed the slurry continuously under pressure. Upon the slurry pressure feeding, the valves connected to the supply chamber lower portion are prevented from closing due to a packing condition.

Abstract: A slurry transport system including a pipeline switching device mounted in pipelines so that when any abnormal condition exists in the slurry transport pipeline, the transport medium return pipeline can be used for transporting a slurry while using the slurry transport pipeline for returning transport medium to the point of origin.

Abstract: A part of the driving liquid discharged from an outlet pipe for driving liquid is supplied, under the control of a first flow control means, to a slurry tank in accordance with the amount of the solid matter supplied thereto, so that the concentration of slurry may be kept at all times to be constant. Further, a clean liquid is supplied, under the control of a second flow control means, in accordance with the amount of driving liquid supplied to the slurry tank.

Abstract: Slurry consisting of water and solid material is fed to fill a plurality of supply chambers arranged in parallel to each other, by the action of slurry pump. The filled slurry is forced to a transferring pipe by the liquid pressure of a high pressure driving liquid pump. A float is positioned on an interface between the slurry and driving liquid within the supply chamber. When a sensor for detecting the position of the float is inoperative due to an external turbulence or the like, a command signal is applied to selected valves in response to a period of time set in a timer.

Abstract: An automatic slurry concentration control system including a mixing tank filled with a charge of slurry of solids containing water, a clear water tank for supplying clear water, a suction tube of a slurry supply pump located in an opening in a lower portion of the mixing tank, and a movable tube for adjusting the opening of the mixing tank, wherein the concentration of slurry in the suction tube can be controlled by adjusting the movable tube, is provided with a clear water control device. The clear water control device is mounted in the clear water tank for controlling the amount of clear water supplied from the clear water tank in accordance with the amount of slurry delivered from the mixing tank.

Abstract: A float of a system for pressure feeding of slurry including a main body in the form of a bellows having a liquid and a gas sealed therein. The float has an apparent specific gravity which may vary depending on the value of pressure of a slurry or a driving liquid, whereby the slurry can be continuously fed from at least one slurry supply chamber by a driving liquid under high pressure to a desired destination.

Abstract: A slurry conveyor system in which a mixture liquid is charged into a supply pipe by a low-pressure mixture liquid pump through a valve, and, thereafter, fresh water of high pressure is supplied by a high-pressure fresh water pump into the supply pipe by a switching of the valve, thereby to force the mixture liquid from the supply pipe into a convey pipe to continuously convey the slurry. The supply pipe is provided with a pressure adjusting device for increasing or decreasing the pressure in the supply pipe to equalize this pressure to the pressure in a pipe connected to the supply pipe, thereby to facilitate the opening of the valve disposed between the supply pipe and the pipe connected to the latter.

Abstract: Slurry consisting of water and solid matters are charged into a plurality of vessels by means of a low-pressure slurry pump, and is discharged into a transfer pipe by fluid pressure generated by a high-pressure driving liquid pump. A float member is positioned at the border of the slurry and the driving liquid in each vessel. Any failure taking place in the apparatus is displaced or informed on the basis of the period of time taken by each float member moving between the upper and lower limit positions or the number of movements.

Abstract: An apparatus for making the supply of a material liquid and relief of pressure of a reaction product liquid in a high-pressure liquefaction reaction such as direct liquefaction of coal. The apparatus includes at least one cylinder having two working chambers separated by a movable float, one of which is adapted to receive the material liquid while the other is adapted to be charged with high-pressure product liquid. A gas discharging pipe having a valve is connected to the side of the cylinder to which the high-pressure product slurry is to be charged. For delivering the product slurry from the cylinder to the outside of the system, the pressure in the cylinder is beforehand relieved and the gases separated from the product slurry are discharged through the valve of the gas discharging pipe. Thereafter, the product slurry filling the cylinder is delivered to the outside by a low pressure of the material slurry supplied to the other side of the cylinder.

Abstract: An apparatus including at least one horizontal feed pipe from which a mixture of liquid and particulate solid material to be transported is discharged into a high-pressure transport pipe by the action of a driving liquid delivered through a vertical pipe connected to the horizontal feed pipe to apply pressure to the mixture in the horizontal feed pipe through an intermediate liquid having a specific gravity lower than that of the mixture and higher than that of the driving liquid. Prior to initiation of an operation, the horizontal feed pipe and a lower portion of the vertical pipe below a float mounted therein are charged with the intermediate liquid and an upper portion of the vertical pipe above the float is charged with the driving liquid. Upon the mixture being delivered by a low-pressure mixture pump to the horizontal feed pipe, the intermediate liquid flows into the vertical pipe and raises the level of the float to return the driving liquid from the vertical pipe to its tank.

Abstract: A control system for an apparatus for hydraulically transporting sedimentation prone slurry containing pulverized or powdered solid material mixed with water. A pipeline resistance of a slurry transport pipe at a proper location is detected by varying the flow rate of the slurry at the starting point of slurry transportation, and the critical flow velocity for slurry sedimentation is determined by using the pipeline resistance. The slurry is economically transported at the flow velocity above the critical flow velocity.

Abstract: In a transportation of solid materials of a wide grain-size distribution, including fine and coarse particles, a liquid as a transportation medium is added to the materials to turn them into slurry, so as to transport the latter hydraulically. The waste solution after the transportation is thickened into a heavy media, by dehydrator and solid-liquid clarifier, and reserved in a heavy media tank adapted to suitably adjust the concentration of the media. The media in the heavy media tank is returned to the transportation source, so as to serve as the transportation medium for transporting the slurry.

Abstract: In transporting solid material of a wide particle size distribution ranging from small to large size particles, a liquid is added to the solid material as a transporting medium to convert the solid material into a slurry to be hydraulically transported. The slurry that has performed the function of transporting the solid material is passed through a water removing device and a solid-liquid separating device to produce a suspension which is stored in a heavy medium tank and returned, after adjusting the concentration of the solid material therein, to the starting point of transportation so that the suspension can be recycled for use as a heavy transporting medium.

Abstract: A loudspeaker system has a cabinet in which a loudspeaker is mounted, the cabinet supporting therein a hollow duct which provides sound communication between the exterior and interior of the cabinet. A standing wave prevention member made of a sound absorbent material is disposed within the duct in spaced relation thereto, the member being smaller in volume than the duct.

Abstract: To prevent erosion-corrosion of capsules moving by means of a fluid through a pipe line, straight chain, macromolecular materials are deposited on the surfaces of capsules before introduction into the pipe line, a corrosion inhibitor is added to the fluid, and said corrosion inhibitor of higher concentration is deposited to the capsules before a temporary exposure to the atmosphere.