Abstract: This invention makes it possible to freely exchange an attachment 20, to which is connected a flexible cable 21 used as an energy supply line and a signal line, on an end surface of a ram 13 of a spindle head of a machine tool having a plurality of control axes. Support means 26a, 26b, and 28 supports the cable in such a manner that this cable 21 can follow the motions of the spindle head. A conveyor means conveys the attachment between an attachment/detachment position at the end surface of the ram 13 and a position at which the attachment 20 is stored, with the cable 21 still connected thereto. The automatic attachment exchange apparatus of this invention automatically exchanges attachments while cables, such as energy supply cords and signal lines, are still connected to the attachments, thus resolving the inconvenience of connecting and disconnecting cables.

Abstract: A linear motor device includes a primary linear motor member and a secondary linear motor member shaped of teeth of a comb with a plurality of projecting portions arranged at predetermined intervals. Recesses defined between the projecting portions are filled up with filler members for flattening a surface of the secondary linear motor member facing the primary linear motor member. Therefore, it is possible to remove chips from the surface easily. Since the filler members are made of low magnetical permeability material, the magnetic shielding between the neighboring projecting portion can be maintained. A linear motor device for a machine tool includes a bar type secondary linear motor member having both ends supported by an immovable member of the machine tool and a cylindrical primary linear motor member attached to a movable member of the machine tool.

Abstract: An apparatus for controlling the opening/closing of a mechanism for clamping a work machined by a numerically controlled machine tool, comprising a driver for the clamping mechanism. The apparatus controls the opening/closing of the clamping mechanism on the basis of measured data on the distance of a main shaft provided in the machine body from the origin position of the machine, measured data on the moving speed of the main shaft, coordinate values of a clamp pawl of the clamping mechanism and data on a region where the clamping mechanism is opened.