Abstract: A vertical spindle numerically controlled machining center includes a stationary bed or base on which a workpiece holding table is slidably mounted for movement along a first axis. A vertically extending upright or column, having a vertically reciprocal spindlehead slidably mounted thereon, is slidably mounted on the bed for movement along a second axis perpendicular to the first axis so that the spindlehead overlies a portion of the table. Within the upright is a recess adjacent to the bed. A tool storage magazine is located in the recess and is slidably mounted on the bed for movement through the recess along an axis parallel to the second axis. During a tool change cycle, the toolholder then held in the spindle is returned to the tool storage magazine by first moving the spindlehead to the ready position and then moving the tool storage drum toward the spindlehead to engage the tool then held in the spindle.

Abstract: A tool storage drum which is adapted to receive and store a plurality of toolholders is rotatably mounted on top of the upright of a horizontal machining center behind the spindle thereof. A tool changer carriage carrying a tool change arm is pivotally mounted on the upright above the spindle and is pivotable between a parked position in which an end of the tool changer arm is adjacent to the tool storage drum and an exchange position in which an end of the tool changer arm is adjacent to the spindle. The tool changer arm is slidably mounted on the carriage for movement between an extended and a retracted position to remove toolholders from their sockets or insert them therein and is rotatable through 180.degree. to interchange its ends for the purpose of exchanging a tool in the spindle for a tool previously removed from the tool storage drum.

Abstract: The bed and upright of a machine tool are made of structural steel tubes which are welded together to form unitary structures. Each of the structural steel tubes is substantially rectangular in cross-sectional shape.

Abstract: A tool storage drum which is adapted to receive and store a plurality of toolholders is rotatably mounted on top of the upright of a horizontal machining center behind the spindle thereof. A tool changer carriage carrying a tool change arm is pivotally mounted on the upright above the spindle and is pivotable between a parked positon in which an end of the tool changer arm is adjacent to the tool storage drum and an exchange position in which an end of the tool changer arm is adjacent to the spindle. The tool changer arm is slidably mounted on the carriage for movement between an extended and a retracted position to remove toolholders from their sockets or insert them therein and is rotatable through 180.degree. to interchange its ends for the purpose of exchanging a tool in the spindle for a tool previously removed from the tool storage drum.