Abstract: A tool holder in a machining center comprising a basic tool holder provided with a tapered fitting hole formed on the nose portion and a small tool having its tapered fitting portion fitted detachably in the tapered fitting hole, wherein a plurality of guide holes for protruding a locking ball are formed on a circumferential wall of the fitting hole, a recess for receiving the locking ball therein is provided on a nose outer peripheral surface of the basic tool holder on which the fitting hole is formed, and a piston actuated at all times toward a base end portion of the basic tool holder is provided slidably and wherein release means for releasing the small tool from being locked by shifting the piston toward a nose of the basic tool holder is provided between the piston and the basic tool holder, a pressure chamber is formed further between the piston and the basic tool holder, and a high-pressure air from a fluid pressure source is connected to each discharge port in the pressure chamber and the fitting ho

Abstract: A replaceable tool is comprised of a tool holder forming a hole providing an engageable ditch on the insert end of the shank, a fitted hole for detachably fitting the shank of this tool holder therein and a sleeve providing a plurality of locking balls to be engaged and removed from the fitted ditch of the tool holder in the fitted hole. In the interior of the fitted hole of the sleeve, the locking balls are pressed on the engageable ditch and the draw collar for applying attraction in the axial direction of the sleeve is slidably provided. When the shank of the tool holder is fitted in the fitted hole of the sleeve, the head portion end of the tool holder is designed to be pressed on the end flange portion of the fitted hole of the sleeve, and when the draw collar is pulled in the axial direction of the sleeve, the shank portion is expanded through locking balls so as to be pressed on the inner wall surface of the fitted hole of the sleeve.

Abstract: A unit case having the shape of a hollow cylinder is demountably mounted in a tapered hole of a spindle by use of a unit holding member and a stock suction nozzle is demountably mounted on the tip end portion of said unit case through a cover member. An end of a suction pipe led to the inside of the hollow of said unit case is fixed on the rear end portion of said unit case, and a stock suction means such as a vacuum pump is provided on the other end portion of said suction pipe through a cleaner.

Abstract: A tool head comprising plural cutting insert holders disposed on a holder main frame fixed to an arbor in such a manner that each is capable of sliding in the radial direction of the arbor; adjusting screws disposed on the holder main frame in parallel to the cutting insert holders in such a manner that movement in both axial and radial directions is restricted; and female screws fixed to the cutting insert holders and brought into tight screw engagement with the adjusting screws, respectively.