A manufacturing method and apparatus for gears for a speed change device. The gears having a large end and a small end forming a reverse-tapered tooth part on an outer circumference thereof, spline teeth of an intermediate material having the small end provided in a rim of the large end thereof, a plurality of dies having a radial shape and an inclination angle to a gear axial line and slidably holding to an inclined axial line on a holding member are slid from outside of the radiation direction toward the center by a pushing cam mechanism, thereby pushing the reverse-tapered blade part formed at the leading end of the die, the spline teeth are formed in the reverse-tapered tooth part, and the die is slid by an extracting mechanism from the center of the radiation direction toward the outside along the inclined axial line.

A manufacturing method and apparatus for gears for a speed change device. The gears having a large end and a small end forming a reverse-tapered tooth part on an outer circumference thereof, spline teeth of an intermediate material having the small end provided in a rim of the large end thereof, a plurality of dies having a radial shape and an inclination angle to a gear axial line and slidably holding to an inclined axial line on a holding member are slid from outside of the radiation direction toward the center by a pushing cam mechanism, thereby pushing the reverse-tapered blade part formed at the leading end of the die, the spline teeth are formed in the reverse-tapered tooth part, and the die is slid by an extracting mechanism from the center of the radiation direction toward the outside along the inclined axial line.

A method of making a worm gear. The method includes forming a gear blank having a plurality of individual lugs formed about an outer circumferential edge of said blank to facilitate a uniform flow of a material around said plurality of individual lugs. The method also includes molding said material around said plurality of individual lugs to form a ring.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

Equipment including a rigid plate provided with a plurality of cutters configured to be impressed in sequence against a swaged annular collar of an inner ring of a wheel hub, the collar being formed with a first radial profile; the cutters sliding axially through the plate and towards a first face of the plate resting in abutment against the collar; wherein the first face of the plate is provided in the region of the cutters with a concave annular seat having a second radial profile configured to copy at least partly the first radial profile of the collar, the annular seat being configured to be passed through by the cutters during the step for impression against the collar and to contain any radial flow of the metallic material which forms the collar.

A workpiece executes a rotation movement about a longitudinal axis and is machined by a tool in a multitude of reshaping engagements, in which an active region of the tool comes into contact with the machining region. The tool is held by a tool holder. The tool holder is mounted in an orbiting body so as to be rotatable about a rotation axis and is driven to carry out a rotating movement about the rotation axis, and is driven to carry out an orbiting movement by the orbiting body. Rotation movement of the workpiece is synchronised with the orbiting movement of the tool holder and the rotating movement of the first tool holder is synchronised with the orbiting movement of the tool holder.

A method of making a bicycle sprocket having a rotational center axis basically includes providing an annular portion and forming a first tooth and a second tooth. The annular portion is made of a base material and has a plurality of teeth. At least one of the teeth is processed to form a first tooth, and at least one other of the teeth is processed to form a second tooth. The first tooth has a first axial chain engaging width that is smaller than a first axial spacing of an outer link of a bicycle chain and larger than a second axial spacing of an inner link that is coupled to an outer link. The second tooth is formed to have a second axial chain engaging width that is smaller than the second axial spacing. The second tooth is formed by deforming the base material.

A method of making a bicycle sprocket having a rotational center axis basically includes providing an annular portion and forming a first tooth and a second tooth. The annular portion is made of a base material and has a plurality of teeth. At least one of the teeth is processed to form a first tooth, and at least one other of the teeth is processed to form a second tooth. The first tooth has a first axial chain engaging width that is smaller than a first axial spacing of an outer link of a bicycle chain and larger than a second axial spacing of an inner link that is coupled to an outer link. The second tooth is formed to have a second axial chain engaging width that is smaller than the second axial spacing. The second tooth is formed by deforming the base material.

To provide a rotating member that allows formation of protrusions to be dug into an opposite surface with a simple configuration, and that can prevent a direction-dependent reduction of anti-slip effect and provide sufficient slip prevention in the direction of torque as well as in the radial direction, and a method of forming this rotating member. The rotating member has a boss and an anti-slip surface on at least one of both axial end faces of the boss. The anti-slip surface includes a plurality of crater-like depressions each having a peripheral protrusion. At least some of the plurality of crater-like depressions are arranged serially to form a plurality of crater chains.

The present disclosure relates to a seat height adjustment device for adjusting the height of a seat cushion in relation to a seat frame, in particular, an upper rail, the seat height adjustment device comprising an actuating device, which may be, in particular, an electric motor, with a toothed pinion driven by the actuating device, and a toothed gear rack, the toothed gear rack comprising a hinge end for hinging onto the vehicle seat, and a front end including a gear rod region engaging with the toothed pinion, for adjusting the hinge end upon rotation of the toothed pinion. The present disclosure provides that the toothed gear rack is hot forged, the toothed gear rack comprises, between the hinge end and the gear rod region, a reinforced region, and the reinforced region comprises a profile.