Apparatus and method for bending a glass tube to a U shape

An apparatus for bending a glass tube to a U shape having two generally parallel legs each having a longitudinal axis, said glass tube having a centrally disposed predetermined zone for bending, a diameter, and an axis, the apparatus comprising:

• a pair of chucks for holding said glass tube at both sides of the centrally disposed predetermined zone for bending;
• a heating device, said heating device cooperating with said chucks so as to heat and soften said glass tube in the predetermined zone for bending;
• a turning mechanism on which said chucks are mounted, said turning mechanism being operable to rotate each of said chucks about a respective turning center, said turning centers being disposed along a line generally parallel to said axis and spaced from said axis by a first predetermined distance, said turning centers being spaced from each other along said line by a second predetermined distance which is less than a third predetermined distance defined by the separation of the longitudinal axes of said generally parallel legs;
• a bending drum to guide bending at said predetermined zone;
• a moving device for said bending drum, said bending drum being mounted on said moving device, said moving device being movable so that said bending drum comes into contact with said glass tube in said predetermined zone thereof immediately before the glass tube is bent by said turning mechanism and so that said bending drum is removed from said predetermined zone of said glass tube before bending is complete.