Abstract: Disclosed is a resin composition for an optical material which contains a base polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C). Also disclosed is a resin film for an optical material which is made of such a resin composition for an optical material. Specifically disclosed is a resin composition for an optical material which has high transparency and high heat resistance, while enabling formation of a thick film with high precision. This resin composition is particularly useful for a resin film which is used for forming optical waveguides. Also specifically disclosed are a resin film for an optical material using such a resin composition and an optical waveguide using such a resin film.

Abstract: The present invention relates to a resin composition for an optical waveguide comprising (A) a photopolymerizable monomer, (B) a binder polymer and (C) a photoinitiator, wherein the photopolymerizable monomer (A) contains a hydroxyl group-containing fluorinated mono(meth)acrylate base compound. Provided are a resin composition for an optical waveguide which has a high transparency in a wavelength of 1.3 ?m and which is excellent in formation of a thick film and an adhesive property and an optical waveguide prepared by using the same.

Abstract: Disclosed is a resin composition for an optical material which contains a base polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C). Also disclosed is a resin film for an optical material which is made of such a resin composition for an optical material. Specifically disclosed is a resin composition for an optical material which has high transparency and high heat resistance, while enabling formation of a thick film with high precision. This resin composition is particularly useful for a resin film which is used for forming optical waveguides. Also specifically disclosed are a resin film for an optical material using such a resin composition and an optical waveguide using such a resin film.

Abstract: The present invention relates to a process for producing an optical waveguide, including the steps of applying a cladding layer-forming resin onto a substrate and curing the resin to form a lower cladding layer; laminating a core layer-forming resin film on the lower cladding layer to form a core layer; subjecting the core layer to exposure to light and development to form a core pattern; and applying a cladding layer-forming resin over the core pattern to embed the core pattern therebeneath, and curing the resin to form an upper cladding layer, wherein the step of forming the core layer includes the steps of (1) allowing the core layer-forming resin film to be temporarily attached onto the lower cladding layer using a roll laminator, and (2) thermocompression-bonding the temporarily attached core layer-forming resin film onto the lower cladding layer under a reduced pressure. There is provided the process for producing an optical waveguide having a uniform core with a good productivity.

Abstract: The present invention relates to a resin composition for an optical material comprising (A) a carboxylic acid-modified phenoxy resin, (B) a polymerizable compound and (C) a polymerization initiator, a resin film for an optical material comprising the above resin composition and an optical waveguide having a core part and/or a cladding layer formed by using the same. Provided are a resin composition for an optical material which is excellent in a heat resistance and a transparency and which is soluble in an alkaline aqueous solution, a resin film for an optical material comprising the above resin composition and an optical waveguide produced by using the same.

Abstract: The present invention relates to a flexible optical waveguide including a core portion and a cladding layer which has an increment of insertion loss of 0.1 dB or less upon subjecting the waveguide to a 360° bending test at a radius of curvature of 2 mm, as well as an optical module using the flexible optical waveguide. There are provided a flexible optical waveguide having high flexing property, heat resistance and transparency, as well as an optical module using the flexible optical waveguide.

Abstract: The present invention relates to a flexible optical waveguide including a core portion and a cladding layer which has an increment of insertion loss of 0.1 dB or less upon subjecting the waveguide to a 360° bending test at a radius of curvature of 2 mm, as well as an optical module using the flexible optical waveguide. There are provided a flexible optical waveguide having high flexing property, heat resistance and transparency, as well as an optical module using the flexible optical waveguide.

Abstract: A support member which is securely fixed to a truck frame is constituted by a tubular body portion and a lid portion. A couple of dry electromagnetic brakes are located in a brake accommodation room within the tubular body portion. The support member is assembled with an electric motor. A drum member which accommodates a planetary reduction gear mechanism is rotatably mounted on the outer periphery of the support member through bearings. A floating seal is provided between the support member and the drum member, and a seal ring (45) is provided between an axial bore in the support member and a coupling shaft. Thus, the two dry electromagnetic brakes are accommodated in the support member, safely shielded from lubricant oil.

Abstract: A hydraulic drive system comprises directional flow control valves (10a-f) for selectively supplying a hydraulic fluid from a first hydraulic pump (1a, 1b), inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid delivered from a second hydraulic pump (3a, 3b) to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders, a bypass flow control valve (204) disposed in a line (104) connecting the supply line (100) and a reservoir (2), and a controller (31) for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. Thus, the number of flow control valves and the length of piping required for their connection can be reduced, and a total pressure loss can be further reduced.

Abstract: The present invention relates to a phenoxy resin for an optical material obtained by subjecting at least one selected from specific difunctional epoxy resins and at least one selected from specific difunctional phenols to polyaddition reaction, wherein a film comprising the above phenoxy resin has a refractive index of 1.580 or less at 25° C. and a wavelength of 830 nm, a resin composition for an optical material containing the above phenoxy resin, a resin film for an optical material comprising the above resin composition and an optical waveguide produced by using the above resin composition and/or the above resin film.

Abstract: The present invention relates to a flexible optical waveguide prepared by using a resin film for forming an optical waveguide for at least one of a lower cladding layer, a core layer and an upper cladding layer, wherein a ten point average roughness (Rz) on a surface of either one of the lower cladding layer and the upper cladding layer is 0.5 ?m or more and 10 ?m or less, a production process for the same and an optical module prepared by using the flexible optical waveguide. Provided are a flexible optical waveguide which is excellent in an adhesive property in compounding with an electric printed wiring board and turning a flexible optical waveguide into a multilayer, a production process for the same and an optical module prepared by using the flexible optical waveguide.

Abstract: Disclosed is a resin composition for an optical material which contains a base polymer (A), a photopolymerizable compound (B), and a photopolymerization initiator (C). Also disclosed is a resin film for an optical material which is made of such a resin composition for an optical material. Specifically disclosed is a resin composition for an optical material which has high transparency and high heat resistance, while enabling formation of a thick film with high precision. This resin composition is particularly useful for a resin film which is used for forming optical waveguides. Also specifically disclosed are a resin film for an optical material using such a resin composition and an optical waveguide using such a resin film.

Abstract: The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.

Abstract: The control valve apparatus holds a seat valve member in a position seated on a valve seat to thereby prevent a backward flow even if the pressure in the inlet chamber side becomes lower than the pressure in the outlet chamber side. With a pilot control valve member is in a closed state, when the pressure in the inlet chamber is higher, a pressurized medium is introduced to the control pressure chamber via a first valve unit and is cut off from the outlet chamber by a second valve unit. When the pressure in the outlet chamber is higher, the pressurized medium is introduced to the control pressure chamber via the second valve unit and is cut off from the outlet chamber by the first valve unit.

Abstract: A hydraulic drive system has directional flow control valves (10a-f) for selectively supplying a hydraulic fluid, inflow control valves (201-203) disposed respectively in branch lines (150A-C) branched from a supply line (100) for supplying a hydraulic fluid to rod pushing-side chambers (5aA, 5bA, 6A, 7A) of hydraulic cylinders. A bypass flow control valve (204) is disposed in a line (104) connecting the supply line (100) and a reservoir (2). A controller (31) is provided for computing control variables corresponding to operation command signals from control levers (32, 33) and controlling the inflow control valves (201-203) and the bypass flow control valve (204) in accordance with the computed control variables. As a result, the number of flow control valves and the length of piping required for connection of the flow control valves can be further cut, and a total pressure loss can be further reduced.

Abstract: Fault diagnosis of hydraulic pumps is made automatically during an actual operation of a working machine, particularly when there is a problem with horsepower limiting control of the hydraulic pumps. A controller 50 performs horsepower limiting control for a plurality of variable displacement hydraulic pumps 1 to 6. The controller 50 measures a pump delivery pressure and pump delivery rate of each hydraulic pump when the pump delivery rate reaches a maximum during operation of the hydraulic drive system based on their detected values, collects the measured values as fault diagnostic data, and then compares a calculated target pump delivery rate with the collected pump delivery rate to decide if there is a fault of the hydraulic pump.

Abstract: A winch over-winding prevention apparatus includes: a winch drum that is driven for up/down hoist in response to a command issued through an operating lever; a stop switch that is activated when a suspended object raised or lowered as a hoisting cable wound around the winch drum is further taken up or fed out is hoisted up to a predetermined stop position; and a stop device that stops drive of the winch drum when the stop switch is activated, and further includes: a speed detection device that detects a hoist speed of the suspended object; a speed reduction device that reduces a drive speed of the winch drum once the suspended object reaches a predetermined speed reduction start position; and a speed reduction control device that calculates a deceleration rate of the winch drum in correspondence to the hoist speed of the suspended object detected by the speed detection device and controls drive of the speed reduction device in response to a speed reduction command corresponding to the deceleration rate.

Abstract: In a pump fault diagnostic apparatus for a hydraulic drive system, it is possible to make a fault diagnosis of hydraulic pumps automatically during an actual operation of a working machine and to detect a fault when there is a problem with horsepower limiting control of the hydraulic pumps as well. A controller 50 performs horsepower limiting control for a plurality of variable displacement hydraulic pumps 1 to 6.

Abstract: A swivel control apparatus according to the present invention , includes: a hydraulic pump; a hydraulic motor for swiveling which is driven by hydraulic oil emitted from the hydraulic pump; a control valve which controls a flow of hydraulic oil which is supplied from the hydraulic pump to the hydraulic motor for swiveling, and at a neutral position of the control valve cuts off from one another a pair of ports which communicate to input and output ports of the hydraulic motor; a valve device which communicates and cuts off from one another a pair of conduits which are respectively connected to the input and output ports of the hydraulic motor for swiveling; a pressure detection device which detects respective pressures in the two conduits and outputs pressure signals; a rotational speed detection device which detects a physical quantity based upon a rotational speed of the hydraulic motor for swiveling and outputs a rotational speed signal; a mode selection device which selects a neutral brake mode and a neut

Abstract: A hydraulic drive system for a supersized hydraulic working machine such as a hydraulic excavator includes hydraulic pumps connected to main lines through a delivery line and a supply line. Branch portions from the main line include flow control valves for allowing a hydraulic fluid to flow from the hydraulic pumps toward hydraulic cylinders. A hydraulic reservoir is connected to the main lines through a reservoir line and a drain line. Other branch portions for the drain line include flow control valves for allowing a hydraulic fluid to flow from the hydraulic cylinders toward the hydraulic reservoir. A line branched for the delivery line includes a bypass valve for supplying the hydraulic fluid delivered from the hydraulic pumps to the supply line at a desired flow rate and returning the remaining hydraulic fluid to the hydraulic reservoir.