The present invention provides a new bending apparatus and bending method of a tube material which makes it possible to achieve all of bending by a large bending radius not requiring large scale equipment or die, bending resistant to wrinkling and buckling at an inner side of the bending, and bending with a high productivity, that is, a ram bending apparatus using a punch 12 and a set of rolls 13, 13 for three-point bending of a tube material wherein the punch 12 has a groove 12a of a width of the width of a circular tube 11 or more and wherein the set of rolls 13, 13 are supported by a frame 14. The rolls 13, 13 can freely move on the frame 14 in directions away from each other in a state contacting the punch 12. The frame 14 has a hollow space 14a enabling free movement of the descending punch 12 and the circular tube 11 bent along with this during the bending of the circular tube 11.

The present invention provides a new bending apparatus and bending method of a tube material which makes it possible to achieve all of bending by a large bending radius not requiring large scale equipment or die, bending resistant to wrinkling and buckling at an inner side of the bending, and bending with a high productivity, that is, a ram bending apparatus using a punch 12 and a set of rolls 13, 13 for three-point bending of a tube material wherein the punch 12 has a groove 12a of a width of the width of a circular tube 11 or more and wherein the set of rolls 13, 13 are supported by a frame 14. The rolls 13, 13 can freely move on the frame 14 in directions away from each other in a state contacting the punch 12. The frame 14 has a hollow space 14a enabling free movement of the descending punch 12 and the circular tube 11 bent along with this during the bending of the circular tube 11.

A tubing bender device includes a frame, handle, ratchet mechanism, slide rod and a frame notch. The tubing bender may be easily disassembled and assembled into a forward or reverse configuration through the use of connectors, two brackets and a bending mandrel. Reversibility is also provided by a cross bow bar support releasably secured to either the slide rod or to a bracket. The cross bow bar support may also be inverted to position die heads in either an upward or downward direction. Repositionable die heads may also be rotated relative to the support into an operative configuration when bending smaller diameter tubing. The repositionable die heads are rotated relative to the support into a non-operative configuration when bending larger diameter tubing.

A tubing bender device includes a frame, handle, ratchet mechanism, slide rod and a frame notch. The tubing bender may be easily disassembled and assembled into a forward or reverse configuration through the use of connectors, two brackets and a bending mandrel. Reversibility is also provided by a cross bow bar support releasably secured to either the slide rod or to a bracket. The cross bow bar support may also be inverted to position die heads in either an upward or downward direction. Repositionable die heads may also be rotated relative to the support into an operative configuration when bending smaller diameter tubing. The repositionable die heads are rotated relative to the support into a non-operative configuration when bending larger diameter tubing.

Bending mandrils and related bending machines and methods are disclosed, which include at least one ultra-high molecular weight (UHMW) material. The mandril, which may comprise or consist of the UHMW material, is placed within an interior of a structure to be bent before the structure is bent about a pending die of the bending machine. Kerf cuts may be provided at the mandril for added flexibility. Other components of the bending machine, such as the following block and/or the bending die may also include panels of surfaces comprising a same or different UHMW material.

Bending mandrils and related bending machines and methods are disclosed, which include at least one ultra-high molecular weight (UHMW) material. The mandril, which may comprise or consist of the UHMW material, is placed within an interior of a structure to be bent before the structure is bent about a pending die of the bending machine. Kerf cuts may be provided at the mandril for added flexibility. Other components of the bending machine, such as the following block and/or the bending die may also include panels of surfaces comprising a same or different UHMW material.

Bending mandrils and related bending machines and methods are disclosed, which include at least one ultra-high molecular weight (UHMW) material. The mandril, which may comprise or consist of the UHMW material, is placed within an interior of a structure to be bent before the structure is bent about a pending die of the bending machine. Kerf cuts may be provided at the mandril for added flexibility. Other components of the bending machine, such as the following block and/or the bending die may also include panels of surfaces comprising a same or different UHMW material.

Bending mandrils and related bending machines and methods are disclosed, which include at least one ultra-high molecular weight (UHMW) material. The mandril, which may comprise or consist of the UHMW material, is placed within an interior of a structure to be bent before the structure is bent about a pending die of the bending machine. Kerf cuts may be provided at the mandril for added flexibility. Other components of the bending machine, such as the following block and/or the bending die may also include panels of surfaces comprising a same or different UHMW material.

SUMMARY

The invention relates to a method and a device for expanding at least a section of an initial tube blank (2) made of plastic or metal in such a way that an expanded tube blank (1) is obtained which tapers in the direction of an end of the tube blank that is not affected by the expansion process. The initial tube blank is fixed in a holding device (4) in a first position (6a), a first mandrel (3) is inserted into the initial tube blank, pressed therein and held in the pressed-in position for a predetermined heating time period, so that at least a part of the tube blank is expanded, and finally the first mandrel is pulled out of the expanded tube blank (1), wherein, when the first mandrel is pulled out of the tube blank, either compressed air is blown into the interior of the expanded tube blank through the first mandrel provided with at least one corresponding first air channel (5), or the expanded tube blank is mechanically stripped off.

SUMMARY

The invention relates to a method and a device for expanding at least a section of an initial tube blank (2) made of plastic or metal in such a way that an expanded tube blank (1) is obtained which tapers in the direction of an end of the tube blank that is not affected by the expansion process. The initial tube blank is fixed in a holding device (4) in a first position (6a), a first mandrel (3) is inserted into the initial tube blank, pressed therein and held in the pressed-in position for a predetermined heating time period, so that at least a part of the tube blank is expanded, and finally the first mandrel is pulled out of the expanded tube blank (1), wherein, when the first mandrel is pulled out of the tube blank, either compressed air is blown into the interior of the expanded tube blank through the first mandrel provided with at least one corresponding first air channel (5), or the expanded tube blank is mechanically stripped off.