Patent ID: 7264581

Claim:
A machining center comprising a first column extending longitudinally and having a longitudinal side surface and a transverse side surface; a second column extending longitudinally and spaced from the first column; a crossbeam being mounted transversely on the first and the second columns and having a tool end near the first column; a tool magazine being mounted near the first column, extending transversely and having an inner transverse side surface facing the transverse side surface of the first column; an upper tool exchange device being mounted on the tool end of the crossbeam; a lower tool exchange device being mounted on the inner transverse side surface of the tool magazine, wherein the lower tool exchange device and the upper tool exchange device are located on a virtual plane parallel to the longitudinal side surface of the first column; and a relay tool exchange device being mounted on the transverse side surface of the first column and comprising a guide device being mounted on the transverse side surface of the first column and extending longitudinally; a frame being mounted moveably on the guide device; a tool case being mounted on the frame and aligned selectively with the upper and the lower tool exchange devices; and a driving device being connected to the frame and driving the frame up and down to approach the upper and the lower tool exchange devices.