Abstract: To provide a variable valve driving device which can accurately control the lift amount of valves and can be manufactured at a low cost. The device has: valves (10) serving as intake valves or exhaust valves of an engine; springs (11) for biasing the valves (10) in the valve closing direction; a cam (12) for pressing the valves (10) in the valve opening direction against a biasing force of the springs; a piston (19) joined to the valves (10); a control chamber (21) configured by a piston insertion hole (20) into which the piston (19) is inserted; and a control mechanism (24) for changing the valve closing timing of the valves (10) by controlling the introduction and discharge of a working fluid into and from the control chamber (21).

Abstract: To provide a variable valve driving device which can accurately control the lift amount of valves and can be manufactured at a low cost. The device has: valves (10) serving as intake valves or exhaust valves of an engine; springs (11) for biasing the valves (10) in the valve closing direction; a cam (12) for pressing the valves (10) in the valve opening direction against a biasing force of the springs; a piston (19) joined to the valves (10); a control chamber (21) configured by a piston insertion hole (20) into which the piston (19) is inserted; and a control mechanism (24) for changing the valve closing timing of the valves (10) by controlling the introduction and discharge of a working fluid into and from the control chamber (21).

Abstract: A valve driving device reduces the volume of the pressure chamber and decreases the energy supplied during driving to open the main valve. As a result of this initial energy, the main valve is lifted by inertial motion. When the main valve is opened (lifted), a first actuating valve is opened, and high-pressure actuating fluid is supplied to the pressure chamber. When in this process the pressure in the pressure chamber falls below the pressure of a low-pressure chamber, a second actuating valve opens independently, and low-pressure actuating fluid is introduced into the pressure chamber. By this means negative pressure in the pressure chamber can be prevented, and the main valve can be held in a lift position equivalent to the initial energy. When the main valve is to be closed, an actuator forcibly opens the second actuating valve.

Abstract: A valve driving device reduces the volume of the pressure chamber and decreases the energy supplied during driving to open the main valve. As a result of this initial energy, the main valve is lifted by inertial motion. When the main valve is opened (lifted), a first actuating valve is opened, and high-pressure actuating fluid is supplied to the pressure chamber. When in this process the pressure in the pressure chamber falls below the pressure of a low-pressure chamber, a second actuating valve opens independently, and low-pressure actuating fluid is introduced into the pressure chamber. By this means negative pressure in the pressure chamber can be prevented, and the main valve can be held in a lift position equivalent to the initial energy. When the main valve is to be closed, an actuator forcibly opens the second actuating valve.

Abstract: The present invention relates to a method for reinforcing a structure comprising the steps of forming a primer layer on the surface of a structure to be reinforced; forming if necessary a putty layer on the primer layer; applying an impregnating resin on the formed primer layer provided that the putty layer in case where the putty layer is formed on the primer layer, before, after or before and after cladding with the fiber sheets, to allow the resin to penetrate into the spaces in the fiber sheets; and curing the resin,the said primer, putty and impregnating resin comprising a resin composition which can cure at a temperature not more than 5.degree. C.

Abstract: A digital signal recording apparatus includes: a level encoder for encoding a digital signal into the first to N-th level data, N being an integer greater than 1; a solid state memory having a data storage area and an auxiliary information storage area, the data storage area being writable for the first to N-th level data; and a write controller for, when the writable area in the data storage area is exhausted, freeing at least a part of an area in the data storage area in which level data other than the first level data is stored, for storing level data including at least the first level data into the freed area in the data storage area, and for storing auxiliary information indicating attributes of the stored level data into the auxiliary information storage area.

Abstract: A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a disphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil driver unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.

Abstract: In a vane pump, a pump housing assembly contains a cam ring having an internal cam surface. A rotor carrying plural vanes is disposed within the cam ring and rotated by a drive shaft. Both end surfaces of the cam ring contact with a pair of flat contact surfaces formed within the pump housing assembly, respectively, and the vanes define plural pump sectors between the rotor and the cam ring, together with the rotor, the cam ring and the pair of contact surfaces. The contact surfaces are formed with a pair of intake ports and a pair of exhaust ports. Furthermore, one of the contact surfaces is provided with a pair of pressure leaking grooves formed at locations between the intake ports and the exhaust ports.

Abstract: A speaker system has an acoustic diaphragm and an image projection screen provided on a surface of the diaphragm integrally therewith so as to enable the user to enjoy both realistic image on the screen and powerful sound reproduced through the diaphragm. The rear surface of the diaphragm is closed at a peripheral portion thereof while the central portion of the rear surface of the diaphragm is opened to the exterior, so that the speaker system can provide a high level of reproduced sound pressure in low-pitched region, while the thickness of the speaker is reduced remarkably. The diaphgram can be driven by a plurality of driving units so that the speaker system can operate only with an ordinary stereophonic amplifier.

Abstract: This invention provides a heat-sensitive transfer layer which comprises a substrate and a heat-melting ink layer provided to one surface of said substrate, characterized by providing, between said substrate and heat-melting ink layer, an interlayer which breaks away within itself by separation under heat at the time of heat transfer.

Abstract: This invention provides a heat-sensitive transfer layer which comprises a substrate and a heat-melting ink layer provided to one surface of said substrate, characterized by providing, between said substrate and heat-melting ink layer, an interlayer which breaks away within itself by separation under heat at the time of heat transfer.

Abstract: A parametric loudspeaker utilizes nonlinearity of air relative to ultrasonic waves for producing an audio frequency having super directivity, and to thus provide a limited listening area public address system subject to a large listening area by safeguarding listeners by the provision of a framework for intercepting powerful ultrasonic waves and an acoustic filter. The depth and energy consumption of the parametric loudspeaker are reduced by the use of a reflective plate. Arbitrary directivity is obtained by the provision of a mechanism to move an ultrasonic wave radiator or the reflective plate. The parametric loudspeaker and any other loudspeaker may be combined.

Abstract: A diaphragm for loudspeakers comprises chitin as a natural high polymeric material having a large value of Young's modulus and kraft pulp having large mechanical internal loss. Therefore, the deformation and the partial vibrations of the diaphragm during diaphragm operation do not come out due to the use of the chitin, because the flexural rigidity of the diaphragm is considerably large. Mechanical internal loss is also large owing to the use of the kraft pulp. As a result, it is possible to obtain a loudspeaker which has little fluctuation in frequency response, and which provides a superior sound pressure-frequency response, a superior distortion factor and a superior phase response.

Abstract: A rotary servovalve includes a valve sleeve formed with a supply port for connection to a source of fluid under pressure and distribution ports respectively for connection to opposite fluid chambers of a hydraulic power cylinder, the valve sleeve being formed at the inner periphery thereof with circumferentially spaced sleeve channels respectively in open communication with the supply and distribution ports, and a valve rotor coupled with the valve sleeve for relative rotation thereto, the valve rotor being formed thereon with circumferentially spaced control lands which are arranged to correspond with the sleeve channels when the servovalve is in a neutral position.

Abstract: A control system for a hydraulic tandem pump assembly including a primary pump for supplying fluid under pressure to a power-assisted steering device and a secondary pump for supplying fluid under pressure to a hydraulic motor of an engine cooling fan, which pumps are mounted on a common drive shaft for rotation therewith.

Abstract: A method for manufacturing a concrete structure such as columns and beams with sufficient reinforcement in the shear strength to be durable against earthquakes, etc. A reinforcing member composed of a fiber-reinforced plastic is applied onto the outer periphery of a concrete structural member by winding the fiber strands around the outer periphery of the concrete structural member while impregnating the fiber material with a resin.

Abstract: A heat-sensitive transfer sheet comprising a base film, a first hot melt layer composed mainly of wax, a coloring layer comprising at least one colorant and at least one a resin as a vehicle, and a second hot melt layer composed mainly of wax, these layers being formed on said base film in this order.

Abstract: In a vane pump, a pump housing contains a cam ring having an internal cam surface, in which a rotor carrying eight vanes is rotatable by a drive shaft. A pair of side plates positioned in the receiving bore in contact engagement with the opposite end surface of the cam ring, the internal cam surface and the rotor define a pump chamber. Each of the side plates is formed at its inside surface contacting the cam ring with a pair of intake ports, a pair of exhaust ports and a vane back pressure groove. This groove is always filled with pressurized fluid supplied from the exhaust ports such that the pressurized fluid is directed into vane support slits formed in the rotor.

Abstract: The present invention relates to a lithographic printing plate which can eliminate disadvantages of conventional zinc oxide master papers and has sensitivity sufficient for practical use in respect of long wavelength laser light. The invention contemplates to provide the lithographic printing plate which is fabricated by charging an electrophotographic plate involving a photoconductive layer on a conductive substrate, the photoconductive layer being prepared by dispersing a mixture containing 50 wt % or less of a phthalocyanine pigment/(zinc oxide and zinc sulfide) into a binder resin, exposing the electrophotographic plate to an image to form the electrostatic latent image, developing the exposed electrophotographic plate by the use of an ink receptive toner, and fixing the plate thus developed.