A machine tool has a worktable slidably mounted on a bed for movement along a horizontal X axis opposite a spindle which is journalled for rotation about a horizontal Z axis perpendicular to the X axis, the spindle being slidably mounted on the bed for movement along the Z axis toward and away from the worktable and for movement along a vertical Y axis perpendicular to both the X and Z axes. A workpiece storage support is rotatably mounted on a frame adjacent to the worktable on the side thereof opposite the spindle. The worktable and workpiece storage support have guideways thereon for slidably receiving a pallet carrying a workpiece, the guideways being positioned so that they can be aligned to permit a pallet to be slid from the workpiece storage support to the worktable and vice versa along the Z axis. A pallet transfer bar is provided which is dimensioned on one end to fit in the spindle and is dimensioned on the other end to engage a pallet. To transfer a pallet from the workpiece storage support to the worktable or vice versa, the pallet transfer bar is clamped in the spindle, the worktable and spindle are moved along the X, Y and Z axes to align the pallet guideways and to engage the pallet transfer bar with the pallet, and the spindle is then moved in the appropriate direction along the Z axis to pull the pallet onto the worktable or push it off the worktable.

In a pallet exchange apparatus for a machine tool, a rotary member carried to be rotatable in a horizontal plane mounts thereon a pallet support means which in turn supports a pallet unloaded from the machine tool and a pallet to be loaded into the machine tool. Each pallet is provided with an engaging hook. A transfer member is provided with a transfer hook engageable with the engaging hook to move the pallet to be loaded on the machine tool toward the machine tool. A fixed hook is provided to be engageable with the engaging hook. The rotary member is rotated to move the engaging hook of the pallet to be loaded on the machine tool into engagement with the transfer hook and to move the engaging hook of the pallet unloaded from the machine tool into engagement with the fixed hook.

Quick clamping cylinder for retracting and centering a draw-in nipple, in which the quick clamping cylinder contains a displaceable piston which is subjected to spring forces when retracting and to pressure fluid when releasing, the supply with pressure fluid being effected through the attaching means of the quick clamping cylinder.

Arrangement for clamping and positioning palettes in the correct position, wherein for the clamping of the palettes a draw-in nipple cooperates with a rapid-clamping cylinder. Addtionally, a rotation safeguard is present between the palette and the associated rapid clamping cylinder. This safeguard against rotation is implemented in the form of localizing pins which have a corresponding mechanical strength to prevent movement when clamping force is exerted.

A mechanism for moving a plurality of workpieces toward a work station of a machine tool, loading workpieces into the machine tool, and removing processed workpieces therefrom in which the mechanism for indexing, raising and lowering a walking beam is carried by a slide for extending the walking beam into and removing it from the work station of the machine tool. The processed workpieces withdrawn from the machine tool are removed from the walking beam by a pusher mechanism.