A method for manufacturing an annular member includes: a cylindrical member forming step of forming a cylindrical member with an annular shape from a round bar material; and a cutting and separating step of cutting and separating the cylindrical member over an axial direction of the cylindrical member while rotating the cylindrical member, the cylindrical member being cut and separated by a shear force obtained by restraining molds, which apply an urging force to an outer circumferential surface of the cylindrical member, and by a restraining mold, which is provided with a gap on the outer circumferential surface of the cylindrical member, among a plurality of restraining molds provided on an inner circumferential surface side and an outer circumferential surface side of the cylindrical member along the axial direction, to obtain a plurality of annular members.

In a die-casting machine with toggle-joint or without toggle-joint, a threaded section or a shaped section of horizontal columns is made by first carrying out turning and then rolling.

A piston manufacturing device includes a first forming device (42) configured to form an annular groove (61) in a piston (11), and a second forming device (52) configured to press an edge (15) of an opening (14) of the piston (11) toward other end side in an axial direction of the piston (11) and to form a thick section (65) extruded from an inner circumferential surface (12b) arranged between the edge (15) and the groove (61) toward an axial center side of the piston (11), wherein a recessed section (53) is formed at a portion of the second forming device (52) that is arranged to abut the edge (15) so that an inner circumferential side of the edge (15) is plastically deformed toward the other end side in an axial direction of the piston (11).

A roller for engaging an outer surface of a pipe element during roll forming has a perimeter region defined by three faces. A channel is positioned in one of the faces. The channel extends circumferentially around the perimeter region and provides a void space that reduces the contact area between the face and the side surface of a circumferential groove formed in the pipe element during roll forming. The reduced contact area reduces frictional heating of the pipe and roller as well as the tendency of the roller to slip relative to the floor surface of the groove due to axial force engendered when an asymmetrical groove is formed.

A device for cold working pipe elements has two or more cams, each having a gear which meshes with a pinion to turn all of the cams. Each cam has a cam surface with a region of increasing radius and may have a region of constant radius extending around a cam body. Each cam also has a traction surface extending around a cam body. A discontinuity in each cam surface is aligned with a gap in the traction surface of each cam. The discontinuities and gaps provide clearance for insertion and removal of the pipe element between the cams to form a circumferential groove when the cams are rotated. A cup adjacent the pinion is movable along the pinion axis to engage and disengage from a stop surface on one of the cams. Engagement between the cup and a stop surface prevents rotation of the cam.

Battery pack powered roll groover described herein includes a housing, an inner roller provided on the housing and configured to be received in an inner circumference of a workpiece, a groove roll provided on the housing and configured to produce a groove on the workpiece, one or more motors provided within the housing and configured to drive the groove roll, and an electronic processor electrically connected to the one or more motors. The electronic processor is configured to operate the one or more motors to perform a first operation of moving the groove roll in a radial direction, and operate the one or more motors to perform a second operation of moving the groove roll around a track in a circumferential direction. The first operation is performed to adjust a groove depth on the workpiece. The second operation is performed to produce the groove on the workpiece.

Processing tool for processing a surface of a workpiece. The processing tool includes a tool body which defines a tool axis. At least one first roll element, which is borne by the tool body, is rotatable around a first roll element axis and has a first outer surface with a rough surface structure in at least one first working section configured for rolling contact with the workpiece surface. Further, at least one second roll element, which is borne by the tool body, is rotatable about a second roll element axis and has a second outer surface that, in at least one second working section configured for a rolling contact with the workpiece surface, has a distance (r2) to the tool axis, which is less than a distance (r1) of the at least one first working section to the tool axis.

A tube having sealing ring grooves formed by a sequential rotational process and a shock absorber including the tube, in which durability of a sealing ring fitted in each of the sealing ring grooves is enhanced. An inclination angle (1) formed with respect to a plane (PL1) perpendicular to an axis of a separator tube by a side surface of the sealing ring groove, which is located on an opening end side of the separator tube, is set to 8 or more. With this, a maximum tensile stress to be applied to an O-ring can be reduced to be smaller than a maximum tensile stress in a case of using a backup ring. As a result, the durability of the O-ring can be set equivalent to or enhanced to be higher than durability in the case of using the backup ring.

A piston manufacturing device includes a first forming device (42) configured to form an annular groove (61) in a piston (11), and a second forming device (52) configured to press an edge (15) of an opening (14) of the piston (11) toward other end side in an axial direction of the piston (11) and to form a thick section (65) extruded from an inner circumferential surface (12b) arranged between the edge (15) and the groove (61) toward an axial center side of the piston (11), wherein a recessed section (53) is formed at a portion of the second forming device (52) that is arranged to abut the edge (15) so that an inner circumferential side of the edge (15) is plastically deformed toward the other end side in an axial direction of the piston (11).

A device for cold working pipe elements has two or more cams, each having a gear which meshes with a pinion to turn all of the cams. Each cam has a cam surface with a region of increasing radius and may have a region of constant radius extending around a cam body. Each cam also has a traction surface extending around a cam body. A discontinuity in each cam surface is aligned with a gap in the traction surface of each cam. The discontinuities and gaps provide clearance for insertion and removal of the pipe element between the cams to form a circumferential groove when the cams are rotated.