Abstract: A numerically controlled wire-cutting electric discharge machine composed of a numerical control apparatus controlling a feeding of a piece of work on at least three axes and a wire-cutting electric discharge apparatus. The wire-cutting discharge apparatus comprises a pair of V type slot guides which stretch a wire therebetween, a first and a second drive means which displace the work in the direction of two axes with respect to the wire electrode and a third drive means which rotates at least one of the V type slot guides around a predetermined axis, so that the relative displacement between the piece of work and the wire electrode is controlled via the first and second drive means by two outputs of the numerical control apparatus, the V type slot guide is rotated via the third drive means by another output of the numerical control apparatus so that the V type slot guide is turned a predetermined angle in the direction of the above-mentioned relative displacement.

Abstract: In a tool-indexing apparatus, the apparatus comprises a member being moved in a linear direction, one set of ball screws which connects between the member and a tool-post, a stopper which restricts the linear movement of the tool-post, and two coil springs which resist against the linear movement of the tool-post and the member. During the operation of the apparatus, first, the member together with the tool-post are lifted, and after the tool-post has become abutted against the stopper via one of the two coil springs, the tool-post is revolved by means of one set of ball screws and by the other one of the coil springs for establishing the tool-indexing operation of the apparatus.

Abstract: A drilling machine with an automatic tool changer (A.T.C.) including a driving motor which drives a spindle head to traverse, upwards and downwards and a tool magazine which is rotatably supported by the spindle head and has a plurality of tools, wherein when one of the tools is to be interchanged with another of the tools, said tool magazine is rotated at predetermined angles by the driving motor by means of the spindle head and a link mechanism.

Abstract: A drilling machine with an automatic tool changer (A.T.C.) comprising a driving motor for a spindle head and a tool magazine rotatably supported by the spindle head and provided with a plurality of tool arbors for holding tools, one of the tools being interchanged with another of the tools by intermittent rotation of the tool magazine, and wherein the tool arbors are supported for swinging movement between a protrusion position and a retraction position so as not to obstruct the machining operation.