The invention relates to a device for forming an at least in part closed hollow profile from a board a with a tool comprising a first half having an at least a U-stamp and at least an upper cavity and a second half having two identical at least in part U-shaped die cavities. The U-stamp and the upper cavity of the first tool half are each meshed with an at least in part U-shaped cavity when the tool is shut. The at least one U-stamp and the at least one upper cavity of the first tool half and the at least two at least in part U-shaped die cavities of the second tool half are arranged in a rotationally symmetrical manner to the rotational axis running in the closing direction of the tool.

A method includes: bending a sheet about a mandrel such that the sheet is tubular, wherein the sheet includes a first longitudinal end portion and a second longitudinal end portion; engaging the first longitudinal end portion with the second longitudinal end portion; and passing the sheet between a first knurling wheel and a second knurling wheel such that the first knurling wheel applies a first knurling pattern to the sheet over the first longitudinal end portion and the second longitudinal end portion and the second knurling wheel applies a second knurling pattern to the sheet over the first longitudinal end portion and the second longitudinal end portion.

A method of forming a closed cross-sectional structure press-forming the plate-shaped workpiece into portions corresponding to bottom portion and left and right side wall portions; and providing bend-facilitating lines at the plurality of bend lines; bending the workpiece in a direction that the portions corresponding to the left and right side wall portions approach each other by pressing a punch into a space between a pair of dies while clamping the portion corresponding to the bottom portion between the punch and a pad in a plate thickness direction; and bending the corresponding portions along the bend-facilitating lines by pressing the corresponding portions against an outer periphery of a plug having an outer peripheral shape the same as a final shape of the closed cross-sectional structure while the plug is placed on the portion of the workpiece corresponding to the bottom portion.

A method includes: bending a sheet about a mandrel such that the sheet is tubular, wherein the sheet includes a first longitudinal end portion and a second longitudinal end portion; engaging the first longitudinal end portion with the second longitudinal end portion; and passing the sheet between a first knurling wheel and a second knurling wheel such that the first knurling wheel applies a first knurling pattern to the sheet over the first longitudinal end portion and the second longitudinal end portion and the second knurling wheel applies a second knurling pattern to the sheet over the first longitudinal end portion and the second longitudinal end portion.

A device for manufacturing at least one undercut in a sheet-metal profile that is slotted or closed may include an inner core portion and an outer core portion, which together can be inserted within the sheet-metal profile and/or may support a semi-finished sheet-metal product from which the sheet-metal profile is formed. The inner core portion and the outer core portion may have faces that mate with one another such that when the inner core portion rotates or translates relative to the outer core portion, the outer core portion is forced away from the inner core portion. To cause this behavior, the faces may be undulating, inclined, or cam-like, for example. In effect, a cross-sectional profile of the device may be reduced at least for purposes of extracting the device from the sheet-metal profile after the undercuts have been formed.

A producing method to be disclosed is a producing method for producing a formed metal item that includes a tubular part with a slit. This producing method includes a step (i) of forming U-shaped part having a U-shaped cross section by deforming a metal plate, and a step (ii) of forming the tubular part with the slit by deforming the U-shaped part using a die assembly with a protruding part in such a manner that two end parts of the U-shaped part clamp the protruding part. In step (ii), a cross-section peripheral length LH of the tubular part is made shorter than a cross-section length LU of the U-shaped part.

A workpiece is formed into a shape having curvatures in the longitudinal and width directions required for a final closed cross-sectional shape, and bend-facilitating lines are provided at positions corresponding to bent lines in the closed cross-sectional shape. The workpiece formed in the first step is bent in a direction that left and right side wall portions approach each other by clamping the bottom portions between a punch and pad in the plate thickness direction and by pressing a punch into a space between dies. A plug having an outer shape the same as the final closed cross-sectional shape is placed on the bottom portion of the workpiece formed in the second step, and the bottom portion and the left and right side wall portions are bent along the bend-facilitating lines by pressing the bottom portion and the left and right side wall portions against a periphery of the plug.

A workpiece is formed into a curved shape that has curvatures in the longitudinal and width directions required for a final closed cross-sectional shape. The formed workpiece is bent in a direction that left and right side wall portions approach each other by clamping the bottom portions between a punch and pad in a plate-thickness direction. A pair of flange portions are butted against each other while the formed bottom portions of the workpiece are placed on a pad; and a die cavity having the same shape as the final closed cross-sectional shape is defined between a support surface of the pad supporting the bottom portion and pressing surfaces of a pair of pressure cams pressing the left and right side wall portions. Then, the pair of flange portions are depressed toward the cavity using depressing portions of a second punch disposed above the pair of flange portions.

A roller is provided includes a cylindrical shaft supported by a main assembly of an image forming apparatus or a detachable cartridge. The cylindrical shaft includes a separation region on a circumference of the cylindrical shaft, where a pair of end portions of the cylindrical shaft oppose each other or are in contact with each other with respect to a circumferential direction relative to the circumference of the cylindrical shaft, and wherein the separation region extends in an axial direction of the cylindrical shaft. In addition, a rotatable cylindrical member is mounted around an outer circumference of the cylindrical shaft and is rotatable about the cylindrical shaft while an inner peripheral surface of the rotatable cylindrical member is in contact with an outer peripheral surface of the cylindrical shaft in a region of the cylindrical shaft other than the separation region with respect to the circumferential direction.

The invention relates to a device and a method for producing at least partially closed hollow profiles from a sheet by a U-O-forming with a tool set having a U-punch in a first tool half for producing an at least partially U-shaped sheet and an upper die in a second tool half for forming an at least partially U-shaped sheet into an at least partially closed hollow profile. Parts of the tool set run parallel to one another in the axial direction of the at least partially closed hollow profile to be produced and are arranged above one another in the closing direction of the tool halves, wherein a common matrix receiver is provided between the tool halves of the tool set, which receiver comprises at least two identical, partially U-shaped dies for the tool set and can rotate about its axial axis.