摘要:
A process for the formation of a thread form in a substantially elongate member (1), wherein the thread form includes at least one rib (3) spaced apart from at least one other rib along the elongate member and wherein the thread form has a relatively coarse rib spacing but a fine thread pitch.
摘要:
The object of the present invention is to provide a bolt that effectively prevents gouging, seizure and racing between the bolt and nut without the aid of a guide boss and is effective when combined with the case nut. Said object can be attained by providing a bolt having a threaded shank portion (103) wherein a plural number of notched faces (104,105) slanting toward the end of said threaded shank portion (103) at an angle ranging from ±15° to ±80° toward the axis of said threaded shank portion (103), are formed at the beginning of the thread part (103A) of said threaded shank portion (103).
摘要:
In a method of manufacturing anchor bolts to be fixed on concrete structures there is a preliminary step of heading a steel rod to form at an upper end thereof, a head (13) having a tapered surface (13 a ) tapering downwardly from the upper end and, decreasing in diameter subsequently a male screw (14) is formed at the other end of a rod by thread-rolling, and simultaneously a part adjacent to the head is rolled to form a reduced diameter rod-portion by gradually displacing a surface layer of the rod-portion (15) inwardly and outwardly to give rise to inner (18) and outer (17) transient swells respectively forming a stopper and a tapered portion merging into the tapered surface (13 a ) of the head. An expansible sleeve is loosely fitted on the reduced diamter rod-portion, with the sleeve being made by die-cutting and bending a metal plate into a cylindrical shape of an outer diameter substantially equal to outer diameter of the screw (14).
摘要:
Including: an intermediate-formed product forming process forming a shoulder part 3, a pipe part 18, a tapered part 17 and an aperture-end part 16 above a trunk part; and a screw-forming forming a screw-thread part by an inner mold 64A and an outer mold 64B in which the pipe part 18 is sandwiched therebetween, an outer diameter of the pipe part is formed to an intermediate diameter between a ridge diameter and a bottom diameter of the screw-thread part in the intermediate-formed product forming process, and in the screw-forming process, the screw-thread part is formed from the tapered part to the pipe part so as to form a screw-starting part is formed at an intermediate position of the tapered part, a height of a first step of a right-hand screw-type protrusion of the inner mold is formed to be lower than a height of a second and subsequent steps in an angle range of 90° circumferentially continuing from the screw-starting part, and rolling a screw-forming tool having the inner mold and the outer mold with revolving in a left-hand direction seeing from an aperture-end toward a bottom part of the intermediate-formed product.
摘要:
The inventive method of forming anchor bolts comprises following steps. A rod-shaped workpiece (26) is roll-formed by penetrating the rod-shaped workpiece (26) with two wedge-shaped tools (34,35) at two points (46,47). The two points (46,47) are arranged on opposite sides and axially separated of a plane (33) perpendicular to an axis of the rod-shaped workpiece (26). The two wedge-shaped tools (34,35) are axially approaching to the plane (33) while the rod-shaped workpiece (26) is revolved around the axis (38). The roll-formed workpiece (26) is separated along the plane (33) for forming two bolts. A sleeve is applied around the anchor bolts.
摘要:
Screw (10), bolt or locking ring bolt (20), in each case produced solely by rolling, and production method for such a screw (10), such a bolt or locking ring bolt (20).