Machine tool

Claim 1

A machine tool for machining a work piece, the machine tool of the type having as main spindle head rotatably supporting a main spindle with a tool mount at one end, the spindle head being reciprocable relative to the machine tool frame in the axial direction of the main spindle, the machine tool further comprising: a tool holding member installed in the tool mount of said main spindle; automatic means for changing a tool held in said tool holding member during "double action" reciprocal tool-changing movement of said spindle head, said automatic means including: a. a tool support carried on said frame and movable in the axial direction of said main spindle independently of said main spindle; b. a tool magazine rotatably supported on, and axially movable with, said tool support and having a plurality of tool holders each capable of detachably holding said tool, and spaced about the magazine periphery, said magazine for indexing a selected tool holder into and out of axial alignment with said main spindle; c. first cam-and-crank means interconnecting said main spindle head, said frame, and said tool support for moving said tool support together with said spindle head a predetermined distance during the "double action" movement of said main spindle head relative to said frame, the tool being held in said main spindle also being engaged to be held by one of said plurality of tool holders of the tool magazine during movement in said predetermined distance; d. second cam-and-crank means interconnecting said main spindle head and said frame for causing said tool holding member to release the tool from the tool holding member during a preselected portion of said "double action" movement; and e. means for preventing movement of said tool support below a fixed axial location, the spindle head being axially movable below said fixed location for performing machining operations.