Abstract: A facing and boring head includes a supporting member in the form of a circular disc secured at its back to the spindle of a lathe or the like. A slide is displaceable radially at the front of the supporting member in a guide extending perpendicularly and symmetrically with respect to the axis of rotation and provides for securement of a tool holder thereto. A counterweight is displaceable in the opposite radial direction between the front of the supporting member and the slide. The mass of the counterweight corresponds to that of the slide, including the tool holder and tool. A gear causes an opposite and equal radial movement of the slide and counterweight, depending on a positioning element. A cylindrical housing surrounds the slide, the counterweight, their guides and the gear. The housing is flanged-mounted on the supporting member.

Abstract: A toolholder for recessing operations having at least one recessing tool having a cutting body of hard metal, the recessing tool being arranged in a cylindrical receiving bore in the toolholder and being held by a retaining screw arranged in the toolholder perpendicularly to the receiving bore. A tool support is arranged in the receiving bore and has a semi-cylindrical shank. The flat surface on the semi-cylindrical shank has at least one groove extending parallel to its axis for receiving an exchangeable cutting body slidably mounted in the groove. A clamping jaw for each cutting body is provided in the other remaining half of the receiving bore and, under the action of the remaining screw, is supported at its front, outer end on the top of the cutting body and by its rear end on the supporting surface of the tool support. The clamping jaw has at its front end a shoulder supporting the cutting body in the direction of sliding and is provided with a setscrew extending parallel to the groove.

Abstract: The invention relates to a facing and inside-turning head comprising a supporting body to be fixed by its back to the spindle of a turning machine, a slide shiftable radially at the front of the supporting body in a guide extending perpendicularly and symmetrically with respect to the axis of rotation, to which slide a tool holder can be fixed, and an adjusting rod slidable in the supporting body coaxially with the axis of rotation and the axial movement of which produces a radial movement of the slide via an interposed drive along with a counter weight also actuatable by the interposed drive.

Abstract: A turning tool for use in metal machining having a holder with a first recess for receiving an insert carrier therein. The insert carrier has a second recess for receiving a cutting insert therein. The insert carrier has a planar base face and a generally semicylindrical supporting surface engaging a corresponding semicylindrical support surface in the first recess on the holder. Holding screws are provided for securing the insert carrier to the holder and for securing the cutting insert to the insert carrier. The semicylindrical support surface on the insert carrier is continuous over the side edge thereof and the corresponding semicylindrical support surface in the recess on the holder are both continuous from a base surface to simplify the machining thereof. In addition, the support surfaces effect a good transmitting of forces between the respective components to enhance the durability of the tool.

Abstract: A mounting for a pair of boring tool cutting bits, the mounting being such that the two cutting bits, when present, project beyond a forward end of a mounting member and are displaced through 180.degree. relative to each other. Each of the tool cutting bits is mounted on a respective cutting bit carrier which is radially adjustable relative to and guided on teeth on the mounting member. The teeth extend in the direction of adjustment at right angles to the rotary axis of the mounting member and are parallel. The cutting bit carrier is also adjustable radially by means of an adjusting screw engaging the carrier and extending in the direction of the teeth. The teeth of the two cutting bit cariers is provided on the forward face of the mounting member in a common radial plane with continuous teeth running across the whole breadth of the forward face. The cutting bit carriers have similar teeth on their rear ends facing towards the forward face. The clamping screws are arranged parallel to the rotary axis.

Abstract: An extension for a boring rod with two counter-rotating boring tool carriers. The boring tools of the carriers are arranged at opposite ends of the boring tool carrier and displaced through 180.degree. relative to each other. The boring tool carriers have a cylindrical shaft and are each guided within a chuck socket, which sockets have a cone on their external ends and both sockets are arranged within a through longitudinal bore in a housing capable of being mounted within the boring rod. Threaded rings are screwed into each end of the longitudinal bore and act in conjunction with the chuck socket through their internal conical part to effect an axial seating between the inner end of the chuck socket and an adjusting bushing, movable within the longitudinal bore, which engages by means of two threads running counter to each other with the corresponding threads of the boring tool carrier. A centering device is provided between the housing and the boring rod.

Abstract: A boring tool for working a small diameter bore in a workpiece having a shaft of circular cross-section comprising a clamping portion for supporting the tool and a neck portion extending forwardly therefrom. The forward end of the neck portion carries a cutting plate. The cutting plate is located entirely within the circular cross-section of the neck portion, except for a cutting point on such cutting plate which extends somewhat laterally beyond the circular cross-section of the neck portion. The neck portion has a channel of semicircular cross-section which spirals from the front end thereof toward the clamping portion of the shaft, the spiral being in the directions of rotation and of feed of the workpiece with respect to the tool. In a modification, a cuttings breaker is mounted to overlie the cutting plate, extends close to the cutting point and has an axially extending cuttings breaking channel running the length thereof parallel to the axis of the neck portion and opening toward the cutting plate.