Abstract: An oil-free chain has bushings which protrude from the outer surfaces of the inner link plates into which they are press-fit, and extend into bushing supporting bores formed in the inner surfaces of the outer link plates of the chain. These bushing supporting bores are formed by a pressing operation which produces offsets in portions of the outer plate, so that, as the bushing supporting bores are formed in the inner surfaces of the outer plates, bosses are simultaneously formed on the outer surfaces. The connecting pins of the chain are press-fit into pin holes in these bosses. The bushing supporting bores are formed without removal of material by machining, and therefore the strength of the outer plates is not compromised.

Abstract: A cylindrical bearing member, which can hold lubricating oil in blind grooves as oil reservoirs for a long period of time to exhibit a lubricating function sufficiently, the blind grooves being efficiently mass-produced on the inside of the cylindrical member at low cost. The cylindrical bearing member has an inner circumferential surface having a plurality of blind grooves and is formed as a hollow open-ended cylindrical member with a bottom from a circular column-shaped crude material or blank. The blank includes a tapered inner circumferential surface at its open end. A groove forming die pin including groove forming protrusions is pushed from the open end towards the bottom to obtain a cylindrical member in which a plurality of grooves are formed on the inner surface.

Abstract: A method for monitoring hydrogen gas and a hydrogen flame wherein an object light having a wavelength of about 309 nm and resulting from two or more laser beams, which have been irradiated to a space to be monitored, is collected and converted to an electronic image, and the electronic image is amplified and converted back to an optical image, thereby imaging a spatial intensity distribution of light at a specific wavelength. A device for monitoring hydrogen gas and a hydrogen flame, which comprises two or more laser beam sources, means for collecting an object light having a wavelength of about 309 nm and resulting from laser beams, which have been irradiated to a space to be monitored, image producing means for converting the object light to an electronic image, amplifying the electronic image, and converting back the amplified electronic image to an optical image, and means for imaging a spatial intensity distribution of light at a specific wavelength.

Abstract: A method of making a bushing 100 with blind grooves used as oil reservoirs for a chain, by which a number of blind grooves 112 for oil reservoirs are provided in an axial direction on an inner circumferential surface of a cylindrical steel member in forging processes comprises the steps of: fitting one end of a cylindrical steel member 106 to blind groove forming protrusions HP1 of a hollow die pin HP contained in a blind groove forming die D6, pressing the blind groove forming protrusions HP1 against an inner circumferential surface of the cylindrical steel member 106 while a diameter widening center pin EP inserted from the other end to the one end of the cylindrical steel member 106 is abutted and held on a front end inner circumferential portion HP3 of the hollow die pin HP and pushing a blind groove forming punch P6 into the blind groove forming die D6 while pressing the other end of the cylindrical steel member 106 and sliding an inner circumferential surface 111 of the cylindrical steel member 106 with

Abstract: A method for monitoring hydrogen gas and a hydrogen flame wherein an object light having a wavelength of about 309 nm and resulting from two or more laser beams, which have been irradiated to a space to be monitored, is collected and converted to an electronic image, and the electronic image is amplified and converted back to an optical image, thereby imaging a spatial intensity distribution of light at a specific wavelength. A device for monitoring hydrogen gas and a hydrogen flame, which comprises two or more laser beam sources, means for collecting an object light having a wavelength of about 309 nm and resulting from laser beams, which have been irradiated to a space to be monitored, image producing means for converting the object light to an electronic image, amplifying the electronic image, and converting back the amplified electronic image to an optical image, and means for imaging a spatial intensity distribution of light at a specific wavelength.

Abstract: An oil-free chain has bushings which protrude from the outer surfaces of the inner link plates into which they are press-fit, and extend into bushing supporting bores formed in the inner surfaces of the outer link plates of the chain. These bushing supporting bores are formed by a pressing operation which produces offsets in portions of the outer plate, so that, as the bushing supporting bores are formed in the inner surfaces of the outer plates, bosses are simultaneously formed on the outer surfaces. The connecting pins of the chain are press-fit into pin holes in these bosses. The bushing supporting bores are formed without removal of material by machining, and therefore the strength of the outer plates is not compromised.

Abstract: A gas leakage monitoring method and system capable of ensuring safety of a gas utilization facility by visualizing invisible-to-naked-eye leakage gas and/or flame of leakage gas into the form of an image. The gas leakage monitoring method comprises the steps of collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, converting the detected light into an electronic image, amplifying and then converting the electronic image into an optical image again, and imaging the spatial intensity distribution of the particular wavelength light.

Abstract: A gas leakage monitoring method and system capable of ensuring safety of a gas utilization facility by visualizing invisible-to-naked-eye leakage gas and/or flame of leakage gas into the form of an image. The gas leakage monitoring method comprises the steps of collecting a detected light of a particular wavelength, which is caused by leakage gas and/or a flame of the leakage gas, in a space to be monitored, converting the detected light into an electronic image, amplifying and then converting the electronic image into an optical image again, and imaging the spatial intensity distribution of the particular wavelength light.

Abstract: A cylindrical bearing member, which can hold lubricating oil in blind grooves as oil reservoirs for a long period of time to exhibit a lubricating function sufficiently, the blind grooves being efficiently mass-produced on the inside of the cylindrical member at low cost. The cylindrical bearing member has an inner circumferential surface having a plurality of blind grooves and is formed as a hollow open-ended cylindrical member with a bottom from a circular column-shaped crude material or blank. The blank includes a tapered inner circumferential surface at its open end. A groove forming die pin including groove forming protrusions is pushed from the open end towards the bottom to obtain a cylindrical member in which a plurality of grooves are formed on the inner surface.

Abstract: A cylindrical bearing member which can hold a lubricating oil charged into blind grooves serving as oil reservoirs for a long period of time and thereby exhibit a lubricating function sufficiently and which can be mass-produced at low cost. The cylindrical bearing member is made with a plurality of blind grooves serving as oil reservoirs swaged on the inner circumferential surface of a pipe-shaped seamless cylindrical member by using a hollow die pin including a plurality of grooving protrusions on end portions of the outer circumferential surface of the die pin and provided with a plurality of diameter=expanding slits therein along the longitudinal direction of the die pin, and a diameter-expanding center pin EP, which is retractable in said hollow die pin HP. The hollow die pin is inserted into a hollow cylindrical part, and the center pin is inserted into the die pin to cause the protrusions to penetrate the interior cylindrical surface of the part.

Abstract: A reel for a chain or the like comprises a core portion adapted to have a chain wound around it and a pair of flange portions arranged at opposite ends of the core portion for retaining the chain on the core portion. The core and flange portions are constituted by a plurality of bent rods bonded together. Each of the bent rods comprises a central portion forming part of the core of the reel and a pair of side portions at its opposite ends forming parts of the chain-retaining flanges of the reel. The reel is inexpensive to manufacture, and can be dipped in rust-preventive fluid along with the chain, thereby eliminating the necessity of winding a chain onto a special reel for rust treatment and then rewinding the chain onto another reel for storage or shipment.