Electric pulse tube expander

An electric pulse tube expander for expanding a tube, said tube expander comprising

• a bed;
• horizontal guides mounted on said bed;
• carriage means guided by said horizontal guides;
• a vertical guide mounted on said carriage means;
• an electrode for applying a pulse to a tube to be expanded, said electrode being movable in vertical and horizontal planes, and being mounted on said vertical guide so that it is movable in a vertical plane on said vertical guide;
• a first drive mounted on said bed for moving said electrode in a horizontal plane, said first drive including a first electric motor for producing a torque to move said electrode in a horizontal plane, a first reducer kinematically coupled to said first motor, said first reducer having an output shaft, and a first mechanism for setting the distance of movement of said electrode, said first mechanism being connected to said output shaft of said first reducer and having a first drive shaft operatively coupled to said first reducer, a first drive gear mounted on said first drive shaft, a first driven shaft, a first driven gear mounted on said first driven shaft and having teeth in a number corresponding to a given distance of movement of said electrode, said first drive and driven gear being in coupling relation with each other, a first arm affixed to and projecting from said first driven shaft, a first limit switch operably interacting with said first arm, a first lead screw mounted on said bed and kinematically coupled to the output shaft of said first reducer for moving said electrode in a horizontal plane, said first lead screw moving said vertical guide with said electrode in a horizontal plane;
• a second drive mounted on said horizontal guides for moving said electrode in a vertical plane, said second drive including a second electric motor for producing a torque to move said electrode in said vertical plane, a second reducer kinematically coupled to said second motor, said second reducer having an output shaft, and a second mechanism for setting the distance of movement of said electrode, said second mechanism being operatively coupled to said output shaft of said second reducer and having a second drive shaft operatively coupled to said second reducer, a second drive gear mounted on said second drive shaft, a second driven shaft, a second driven gear mounted on said second driven shaft and having teeth in a number corresponding to the distance of movement of said electrode, said second drive and driven gear being in coupling relation with each other, a second arm affixed to and projecting from said second driven shaft, a second limit switch operably interacting with said second arm, a second lead screw kinematically coupled to the output shaft of said second reducer for moving said electrode in a vertical plane, said second lead screw moving said electrode in a vertical plane on said vertical guide;
• a pulse generator electrically connected to said electrode for producing an electric current pulse for a tube expansion operation;
• and
• control means electrically connected to said pulse generator and to said first and second drives for moving said electrode in horizontal and vertical planes.