APPARATUS FOR DOUBLE-SIDED BENDING OF TUBES IN TWO PLANES Russian patent published in 2007 - IPC B21D7/24 

FIELD: plastic working of metals, in particular, bending of sections from tubular blanks.

SUBSTANCE: apparatus has horizontal bending unit and vertical bending unit which are mounted on frame and provided with bending arms fitted on shafts, drives for moving said units, and blank retainer. Horizontal bending unit has clamp-mold positioned for displacement along guiding columns rigidly fixed on frame, said clamp-mold being secured through foldable levers to pneumatic cylinder rod and having contour conforming with ready part and coming into contact with blank during bending process. Said contour has radial part in the form of half-trough and movable cheeks equipped with oval openings and radial part having radius corresponding to that of horizontal bending unit and terminating in curved portion. Lower portion of radial parts is made in the form of fork and feelers equipped with projections arranged at an angle relative to path of displacement of clamp-mold. Feelers may be adjusted for accurate positioning of movable cheeks by cooperation with fork and by moving along guiding planks fixed on clamp-mold and shouldered pin, which are set on shafts positioned for rotation through rack-and-gear mechanisms. Slide block has working contour formed as half-trough, whose upper part is terminated with curved portion. Curved portions of cheeks and curved portion of half-trough of slide block are formed on condition that molds of vertical bending unit define single groove upon termination of horizontal bending process.

EFFECT: increased efficiency, simplified construction and enhanced reliability in clamping of blank.

6 dwg