Abstract: It is an object to provide a locking bolt, which is capable of tightly fixing a member or the like at an extremely high degree of firmness without being loosened even when vibrations are repeatedly applied thereto, and is manufactured in an extremely facilitated manner. The locking bolt includes: a shank section (1) threaded on an outer circumference thereof; and a head section (2) provided at one end of the shank section (1). The head section (2) includes: a main body portion (201) having a hexagonal cross-sectional shape; and a cylindrical skirt portion (202) provided continuously with the main body portion (201) and formed so as to be spaced radially outward from the main body portion (201) in an expanding manner along a concave surface using a catenary curve surface.

Abstract: A fastening member for appropriately ensuring strength of a peripheral edge part of a tapered-ring-body-shaped part and appropriately reducing external dimensions. A bolt, a nut or a washer employed for fastening a body is fastened by a screw tightening action The fastening member has a tapered-ring-body-shaped part formed into a ring body shape with a gradually increasing diameter toward a seating surface formed into a circular-planar-band-ring-shape concentric with an axis so as to press against the body being fastened. The taper angle of the tapered-ring-body-shaped part is an acute angle, and an upright surface is formed on an outer circumferential surface of the tapered-ring-body-shaped part and vertically erected from the body being fastened.

Abstract: It is an object to provide a locking bolt, which is capable of tightly fixing a member or the like at an extremely high degree of firmness without being loosened even when vibrations are repeatedly applied thereto, and is manufactured in an extremely facilitated manner. The locking bolt includes: a shank section (1) threaded on an outer circumference thereof; and a head section (2) provided at one end of the shank section (1). The head section (2) includes: a main body portion (201) having a hexagonal cross-sectional shape; and a cylindrical skirt portion (202) provided continuously with the main body portion (201) and formed so as to be spaced radially outward from the main body portion (201) in an expanding manner along a concave surface using a catenary curve surface.

Abstract: A cutting machine for a railroad rail performs clamping by use of a screw to fasten a catch arm onto a gauge which indicates a cutting position and is fastened onto a railroad rail. The catch frame is connected to a main body block via slide shafts, and a rotating grinding disk saw, driven by an engine mounted on the main body block, is rocked by working a stroke handle to smoothly raise and lower the rotating grinding disk saw within a cut opening to cut the railroad rail crosswise. By varying the cut of the rotating grinding disk saw, frictional resistance to cutting is reduced and the generation of frictional heat is prevented, permitting use of a small-scale engine and improving the accuracy of the cut.

Abstract: The present invention provides an impact wrench and a bolt-tightening method such that a spring force is applied, through the circumference of a spindle coupled with the output shaft of an electric motor, in the forward direction to a hammer which is capable of forward and rearward movement and rotational motion following the spindle. The hammer and an impact shaft are brought in coaxial mesh alignment by leaving a gap between them in the direction of rotation so that when a bolt to be tightened is inserted into a socket fixed to an end of the impact shaft to permit the bolt to be tightened, the mesh contact with the impact shaft is released as a result of the hammer being lifted up in the rearward direction against the reaction force due to the tightening of the bolt. An impact sensor detects release of the hammer from the impact shaft and an angle sensor measures the angle of rotation of the impact shaft.

Abstract: A drilling machine for a railroad rail, in which the railroad rail is clamped crosswise with respect to a main body case by a catch frame and a clamp arm, includes a cutter advanced perpendicularly with respect to the middle part of the rail by turning the rotating handle of a link mechanism to drill boltholes is specific positions. The drilling position of the bolthole to be drilled in the middle part of the rail is set by a height gauge, secured on the catch frame, and a pitch gauge, mounted on the railroad rail.

Abstract: An indexing and positioning device comprises: a fixed inner ring; and outer ring disposed coaxially, coplanarly, and revolvably therearound with an annular boundary therebetween; a plurality of positioning recesses formed at equal indexing intervals along and straddling the boundary and comprising respective inner and outer parts respectively formed in the inner and outer rings, all recesses assuming a completely assembled state upon combination of the inner and respective outer parts in a specific indexing register; a plurality of positioning balls one of which is floatably accommodated within each of the positioning recesses; a retainer confining and guiding each of the positioning balls; and a clamp ring operable to press the positioning balls inward into the respective positioning recesses thereby to cause accurate and positive centering and positioning of indexing positions of the inner and outer rings relative to each other.

Abstract: A chuck jaw changer is disclosed as mounted on the headstock (24) of an N/C lathe (22) for automatically changing the set of gripping jaws (32) of a quick change chuck (28) on a work spindle (26) with any of other interchangeable sets of gripping jaws (32') being held by a rotary, indexing jaw magazine (34). The jaw magazine has formed therein several jaw grooves (150) each for holding one set of gripping jaws (32'), or the jaw set (32) withdrawn from the chuck, slidably engaged therein in a row. An indexing mechanism (35) revolves the jaw magazine relative to the machine tool for bringing any of the jaw grooves into line with that one of radial jaw guideways (54) of the chuck which is being held in a prescribed jaw change position on the work spindle. A jaw transfer mechanism (36) operates for successively transferring the set of jaws from the chuck into an empty jaw groove in the jaw magazine, and a different set of jaws from the jaw magazine to the chuck.

Abstract: The present invention relates to a lathe to which a long bar stock is automatically supplied by a simple construction utilizing the revolution of a main spindle. Pinch rollers having a hyperboloidal profile are disposed face to face and a circumferential surface of a bar stock is pinched by the pinch rollers. The pinch rollers each have a driving roller concentric therewith and are rotated as one unit. The distance between the opposed pinch rollers can be adjusted to correspond to the diameter of the bar stock. The driving rollers are rotated by rotation of the main spindle for feeding the bar stock in the axial direction by the resulting rotation of the pinch rollers.

Abstract: The present invention relates to an improvement in a mechanism wherein a flywheel which is idly mounted on a spindle of a machining center is easily and speedily connected with or detached from the spindle by a clutch which is fitted on the spindle adjacent to the flywheel for promoting the cutting efficiency by providing spindle inertia of two kinds; one kind for heavy cutting and another for light cutting respectively.