The invention relates to an apparatus (1) for producing a peripheral groove (101) in an end portion (103) of a metal tube (100), in particular a metal tube (100) which is to be coated on the inside, the groove (101) being set up for receiving tube connectors, having a first, rotationally driven roller (3), a second, freely rotating roller (5), the first roller (3) having a roughened or structured surface (6) relative to the second roller (5), a pressing device (15) for producing a relative movement between the first and second roller (3, 5), between a first and a second position, the rollers (3, 5) assuming a first spacing from one another in the first position, which first spacing permits an introduction of a wall of the tube between the rollers (3, 5), and assuming a smaller, second spacing from one another in the second position, which second spacing is smaller than a material thickness (M) of the wall of the tube.

It is proposed according to the invention that the first, driven roller (3) is set up to grip the tube from the outside in the second position and to rotate it, with the result that a peripheral groove (101) is pressed into the tube in the second position when the first roller (3) is driven.

The invention relates to an apparatus (1) for producing a peripheral groove (101) in an end portion (103) of a metal tube (100), in particular a metal tube (100) which is to be coated on the inside, the groove (101) being set up for receiving tube connectors, having a first, rotationally driven roller (3), a second, freely rotating roller (5), the first roller (3) having a roughened or structured surface (6) relative to the second roller (5), a pressing device (15) for producing a relative movement between the first and second roller (3, 5), between a first and a second position, the rollers (3, 5) assuming a first spacing from one another in the first position, which first spacing permits an introduction of a wall of the tube between the rollers (3, 5), and assuming a smaller, second spacing from one another in the second position, which second spacing is smaller than a material thickness (M) of the wall of the tube.

It is proposed according to the invention that the first, driven roller (3) is set up to grip the tube from the outside in the second position and to rotate it, with the result that a peripheral groove (101) is pressed into the tube in the second position when the first roller (3) is driven.

A device for cold working pipe elements has two or more cams, each having a gear. The gears turn synchronously with one another. 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 device for cold working pipe elements has two or more cams, each having a gear. The gears turn synchronously with one another. 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 pipe grooving device includes an assembly adapted to receive an end of the pipe. The assembly includes a cup which surrounds a pipe end stop. The cup and the pipe end stop may be mounted on a fixed pinion about which a carriage rotates. The carriage carries geared cams which engage the pinion and rotate synchronously when the carriage rotates relatively the pinion. The cams engage a pipe element received by the cup and form a circumferential groove in the pipe element. The cup and the pipe end stop move independently of one another axially along a pinion shaft to actuate rotation of the carriage. The cup accommodates dimensional pipe diameter tolerances and mitigates pipe flare and maintains pipe roundness during the grooving process.

A pipe grooving device includes an assembly adapted to receive an end of the pipe. The assembly includes a cup which surrounds a pipe end stop. The cup and the pipe end stop may be mounted on a fixed pinion about which a carriage rotates. The carriage carries geared cams which engage the pinion and rotate synchronously when the carriage rotates relatively the pinion. The cams engage a pipe element received by the cup and form a circumferential groove in the pipe element. The cup and the pipe end stop move independently of one another axially along a pinion shaft to actuate rotation of the carriage. The cup accommodates dimensional pipe diameter tolerances and mitigates pipe flare and maintains pipe roundness during the grooving process.

A pipe grooving device having a plurality of geared cams uses synchronizing gears, each of which meshes with two of the geared cams, to synchronize the rotation of the cams which engage the pipe element to form the groove. The position of the groove relative to the end of the pipe is controlled by a stop body which incorporates a plate mounted ring which engages and disengages with a pipe stop surface on one or more of the cams to limit or permit cam rotation. The pipe stop body is positioned within a cup which receives the pipe element. The cup limits pipe end flare and limits the tendency of the pipe to go out of round during the grooving process. The device mounts on a powered chuck which turns the pipe element.

A pipe grooving device having a plurality of geared cams uses synchronizing gears, each of which meshes with two of the geared cams, to synchronize the rotation of the cams which engage the pipe element to form the groove. The position of the groove relative to the end of the pipe is controlled by a stop body which incorporates a plate mounted ring which engages and disengages with a pipe stop surface on one or more of the cams to limit or permit cam rotation. The pipe stop body is positioned within a cup which receives the pipe element. The cup limits pipe end flare and limits the tendency of the pipe to go out of round during the grooving process. The device mounts on a powered chuck which turns the pipe element.

A roller set for roll forming pipe elements has an outer roller that engages the pipe element at three points to prevent teetering of the pipe element. The outer roller has a summit positioned on a raised feature, the summit comprising a curved surface adapted to burnish the pipe elements.

A roller set for roll forming pipe elements has an outer roller that engages the pipe element at three points to prevent teetering of the pipe element. The outer roller has a summit positioned on a raised feature, the summit comprising a curved surface adapted to burnish the pipe elements.