Abstract: A vertical machine tool with a movable main spindle has a headstock for supporting a spindle having an axis in a vertical direction. A work feeder gives and takes a work between the work feeder and a chuck. The work feeder includes a work feeder frame provided in the vicinity of a machine body, a swivel member driven by a driving means for swivelling, a plurality of pallets mounted on the swivel member, and a supporting device disposed in a work receipt/release position where the pallet is positioned for receiving/releasing the work between the pallet and the chuck. The supporting device supports the pallet, positioned in the work receipt/release position, movably up and down in the direction of the axis of the spindle. The receipt/release of the work may be performed under the condition that the work is kept depressed to the chuck.

Abstract: A turret tool post for a machine tool has a turret having a plurality of turret faces each equipped with a tool for machining, a turret shaft for rotating the turret, a cam follower provided on the turret shaft, a cam having a cam surface engaged with the cam follower to cause the cam follower to rotate, and an indexing motor for driving the cam to index the turret faces. A straight raceway portion is formed on the cam surface of the cam so that the cam follower is not driven to rotate through a predetermined angle. Also disclosed is an apparatus for controlling indexing of the turret tool post which has a turret controller for controlling the rotation of the indexing motor. The speed of the indexing motor is controlled in accordance with whether a door attached to a cover covering the turret and other elements is open or closed.

Abstract: A method of machining the contour of a printed circuit board by effecting a relative feed movement between a rotating tool and the other periphery of the printed circuit board. The electrical current value of a drive motor for driving a spindle to which the tool is attached is detected and an operation is conducted for changing the machining condition in such a manner as to reduce the electrical current value of the spindle drive motor and, at the same time, for changing also tool diameter compensation amount to a value corresponding to the machining condition after the change, at every time the detected electrical current value has reached a predetermined current value immediately before tool breakage and repeatedly by a predetermined number of times.