Abstract: A sewing machine including a needle bar to which a sewing needle conveying a sewing thread is secured, a main shaft to which the needle bar is connected, a loop catcher which cooperates with the sewing needle to catch a loop of the sewing thread conveyed by the needle, a catcher shaft to which the loop catcher is connected, a drive motor which drives at least one of the needle bar and the loop catcher by rotating a corresponding one of the main shaft and the catcher shaft, a first sensor which detects a first reference rotation position of at least one of the main shaft and the catcher shaft and generates a first detection signal indicating that the one shaft is taking the first reference rotation position, a second sensor which detects a second reference rotation position of the drive motor and generates a second detection signal indicating that the drive motor is taking the second reference rotation position, and an indicating device which indicates, based on the first detection signal, that the one of the

Abstract: A maleimide-based copolymer is provided, in which the content of compound (X) shown by the formula (I) is controlled in a range which does not adversely affect the physical properties of the copolymer. Such a copolymer includes an aromatic vinyl-based monomer unit and a maleimide-based monomer unit as essential components, proportion y of the maleimide-based monomer unit in structure is 35 to 65% by weight, and a content of the compound (X) is 3% or less and also, does not exceed a numeral value of 0.06y. The copolymer is prepared by radical copolymerization which is carried out by supplying gradually an aromatic vinyl-based monomer and a maleimide-based monomer into a reaction vessel under a condition of keeping these monomers separated without mixing together beforehand.

Abstract: Light projectors are located outside of a kiln inlet and at positions below the axis of a roller array for generating optical signals in the lengthwise direction. Light receptors are located outside of a kiln outlet and at positions below the axis of a roller array for independently receiving the optical signals from the projectors. When the rollers rotate normally, the light generated from the projectors enter intermediately the receptors. When there is roller breakage, the broken roller falls due to gravity and tilts down. Then, a part of the light generated from the projectors is cut off by the broken roller piece. Hence, no ray reaches the receptor corresponding to the shielded ray. This ensures that roller breakage is detected.

Abstract: A roller driving apparatus for use in a roller hearth kiln has a kiln tunnel and kiln side walls. The apparatus includes a rotary drive shaft, a holder fixedly mounted at one end thereof on the rotary drive shaft, a metal connection pipe detachably mounted on the other end of the holder and including a positioning aperture formed therein, a ceramic roller, and a metallic receiver roller rotatably supporting the driven end of the ceramic roller through a metallic coil spring. The positioning aperture extends along the longitudinal axis of the connection pipe, and the ceramic roller is mounted at a drive end thereof on an end of the connection pipe opposite to the holder for receiving drive power from the rotary drive shaft. The ceramic roller has another, driven end, and extends through the kiln tunnel through one of the kiln side walls of the roller hearth kiln.

Abstract: A workpiece fabric holding device for producing neatly folded pocket pieces for attachment to an article clothing. When a peripheral edge of a patch pocket P put on a gage plate at an operational position is folded back under the gage plate, a folded portion around the edge with a double folded portion formed at the corners of the patch pocket P. Then the gage plate is moved downward and the folded portion and the double folded portion are depressed to a cloth W positioned on a machine table. A hollow is formed on the machine table which opposes and receives the double folded portion. A stopper is arranged in the hollow to prevent the cloth of the folded portion or the double folded portion from being drawn out beyond the periphery of the patch pocket P.

Abstract: A horizontal axis full rotary hook for a sewing machine, including a generally cylindrical hook base having a point of hook, an inner circumferential surface, and a guide groove formed in the inner circumferential surface; and a generally cylindrical bobbin-case holder having an inner circumferential surface, an outer circumferential surface, and a part-circumferential rail provided on the outer circumferential surface, the bobbin-case holder being supported by the hook base such that the bobbin-case holder is freely rotatable relative to the rotary hook while the rail is guided in the guide groove, the bobbin-case holder having a needle aperture which allows a sewing needle with an upper thread to be moved down to a bottom position thereof, the needle aperture having a first inclined inner surface which is opposite to the point of hook with respect to the needle at the bottom position, a distance between the needle at the bottom position and the first inclined inner surface as measured in a direction paralle

Abstract: A casing for a kiln includes at least one casing unit comprising: vertical and horizontal frame members assembled according to the shape of a framework of the kiln; outer plates secured to at least one of the vertical and horziontal frame members for covering the spacings encircled by said vertical and horizontal frame members; guide fittings provided at the spacings between outer plates adjacent in a longitudinal direction of the kiln for slidably supporting the ends of said outer plates; and securing means for securing said outer plates to said vertical frame member or horizontal frame member so that the spacings between the adjacent outer plates are expandable in a longitudinal direction of the kiln.

Abstract: A roller driving apparatus in a roller hearth kiln which has a plurality of ceramic rollers arranged across a kiln tunnel. The ceramic rollers rotate to move articles to be heat treated while conveying them. A rotary drive shaft connects the ceramic roller through a holder and a cylindrical metallic connection pipe which is mounted on the other end of the holder and which includes a positioning aperture formed therein. A leaf spring is fixedly mounted with one end on the holder, and the other end being engageable with the positioning aperture of the connection pipe. The opposite driven end of the ceramic roller is supported on a pair of metallic receiver rollers through a metallic coil spring which is wound on the driven end of the ceramic roller.

Abstract: A waste heat recovery apparatus is disclosed which recovers the waste heat of high temperature exhaust gas discharged from a furnace. The apparatus includes a radiation body made of ceramic material, which is formed with a heat radiation surface arranged adjacent to an exhaust gas outlet of the furnace, and directed toward the inside of the furnace. The radiation body has a plurality of regular channels allowing passage of the exhaust gas therethrough. Exhaust gas passes through the channels and heats the radiation body, and a substantial amount of the holding heat of the exhaust gas is radiated from the radiation surface toward the inside of the furnace, allowing an efficient waste heat recovery.