A hydraulic bender comprises a hydraulic cylinder adapted to cause a mandrel to reciprocate along a longitudinal axis in a first plane in which two forming dies are stationed on either side of the axis. A pneumatic cylinder coupled to the axles of the forming dies and applies torque through a tether and pulley system to the forming dies. As the tube engages both the mandrel and the forming dies, resistive pressure in the pneumatic cylinder applies torque to the forming dies to hold them against the tube during the bending operation. A clamp may be applied to the tube to keep it snug against the mandrel as the forming dies rotate along the sides of the tube during bending. The torque system applies continuous pressure to the tube and permits bending of extremely thin walled tubing such as titanium aircraft tubing without wrinkling.Virtually every complex machine and vehicle in today's industrial society employs cylindrical tubing having one or more arcuate bends between end points. When such tubing fails or must be modified, the original bends usually must be replicated as part of the modification or repair. Often it is inconvenient, uneconomic or impossible to return to the original manufacturer for a duplicate or modified tube. Moreover, repair or modification projects often demand immediate substitution of tubes and cannot await research into availability. Considerable interest therefore exists for commonly available tube bending devices capable of bending tubing on demand from models at hand. Of the devices on the market during recent decades to fill this need, all fall short of the ideal bender. Many cannot bend tubing into angles up to and including one hundred eighty (180°) degrees. Of those that can, most cannot accommodate complex bends in three dimensions, or multiple bends close together on one tube. A need exists for a hydraulic bender which can produce complex bends in three dimensions and closely spaced bends on a single tube.
Advantages- accordingly, it is an object of this invention to provide a hydraulic bender with the following advantages: (a) inexpensive, portable, and quick and easy to use; (b) capable of bending close, multiple bends in any direction, including 180° bends, without tube damage; (c) providing open access to the top and bottom of the machine for visual inspection of the tube during the bending operation; (d ) allows the operator easily to copy existing bends; (e) provides a ready adjustment for bends of varying radii without interference from support plates and brackets; and (f) capable or bending short radius bends in extremely thin walled tubing such as titanium aircraft tubing.
