A rotary cutting unit for a rotary saw has a cross bar and at least one cutting structure, wherein the cutting structure is in contact with the cross bar. The cross bar runs through sleeve holes. The center of gravity of the turning unit is located in an axis of the center of the sleeve holes. The axis is perpendicular to the transverse axis of the crossbar. The rotary saw selectively installs the rotary cutting unit of the corresponding specification, and it can quickly and easily change the aperture of the circular hole to be processed, and with high usability.

The present technology presents system of a guide for widening a drilled hole. In various embodiments the system comprises a hub including a circular central member and a plurality of slots for shims around a circumference of the circular central member. Embodiments include a plurality of shims with the plurality of shims being fit into the plurality of slots around the circumference of the circular central member. Furthermore, the plurality of shims each include a narrow end and a wide end with the narrow end of each of the plurality of shims being in a same direction and the wide end of each of the plurality of shims being in an opposite direction to the narrow end allowing for the guide to fit securely into the existing hole before drilling the new hole.

A cutter holder structure comprises a cutter arbor and a connecting shaft having a tapered section at one end thereof. One end of the tapered section is formed with a first inner screw hole, and another end of the tapered section is formed with a second inner screw hole. The connecting shaft further has a horizontal positioning hole that penetrates through the connecting shaft. Two ends of the positioning hole are formed with cylindrical holes. A reduced hole is defined between the cylindrical holes. A nut has a third inner screw hole at one end and an axial hole at another end. The nut further has a horizontal countersink hole and a horizontal fourth inner screw hole. An eccentric distance is defined between a center of the countersink hole and a center of the fourth inner screw hole. A screw is inserted through the countersink hole and locked into the fourth inner screw hole.

An automatic lathe includes a main spindle that rotates a workpiece about a shaft center, a cutting tool that processes the workpiece, a feeder that moves the cutting tool, an input receiver that receives inputs regarding an eccentric distance and a radius, and a controller that controls the movement by the feeder such as to set a virtual circle having a radius of the distance, to set an offset virtual circle having a center at a position where a center of the virtual circle is offset from the shaft center of the workpiece in the radial direction of the workpiece by the radius, and to move the cutting tool along an circumference of the offset virtual circle in relation to a rotation of the workpiece by the main spindle. A hole is processed, which has the radius at a position away from the shaft center by the distance.

A turning device with static bar includes a motor, a driving shaft and a sleeve, which defines a seat for temporarily accommodating at least one portion of the bar being machined. A machining tool is coupled directly or indirectly on the sleeve. A secondary shaft is interposed between the driving shaft and the sleeve and is coupled to the screw of a first assembly constituted by a first recirculating-ball screw and a respective first lead screw integral with the sleeve. The sleeve and first assembly are coaxial and the driving shaft axis is parallel to and separate from the common axis of the sleeve and first assembly.

The device includes an adjustment element coupled to a pusher shaft, which through the secondary shaft.

makes the screw translate and the assembly lead screw rotate, with consequent rotation of the sleeve and a movement in a radial direction of the tool.

Tool assembly for a rotating device having a drive, a control and a supporting arrangement for at least one tool insert. In order to provide a device for off-round turning which can be constructed with little technical and mechanical effort and nonetheless be used at almost any axial position of a workpiece, the application proposes a tool assembly of the type mentioned above. The tool assembly is designed as a crank drive assembly, wherein the supporting arrangement has a swinging piston unit and the crank drive assembly has a crank unit, and the swinging piston unit and the crank unit are connected to one another by a thrust rod unit.

A double eccentric positioning apparatus uses two equal offset eccentric bushings to accurately position a tool (such as a drill bushing) in two dimensions. Miniature servo motors and precise gearing control the rotation of each eccentric bushing, which controls the direction of the offset vectors. The offset vectors are used to determine the final position of the drill bushing. The desired rotation angles can be mathematically calculated based on desired position. The inner eccentric bushing is located concentric to the offset of the outer eccentric bushing. This allows any position, within a radius of two times the eccentric offset, to be achieved. The use of worm gearing on the eccentric bushings prevents back-driving of the servo motors, due to the lead angle of the worm gears, and the friction between the worm wheel and worm gear.

A boring-bar arrangement includes a boring bar, a securing device, and a clamping bolt. The securing device has a reduction sleeve, which is secured in a tool chuck, which has a front end that faces away from the tool chuck and a protruding hollow section which receives the boring bar. The hollow section has a hollow-section interior, a hollow-section outer wall, and a hollow-section wall which is arranged therebetween. The hollow-section wall has a first thickness in a side region where the cutting tool protrudes from the boring bar which is less than a second thickness in a rest of the hollow-section wall. The boring bar is releasably secured as a replaceable head, via its back end, at a front end of the protruding hollow section. A front end of the clamping bolt has a male thread which sits in the female thread of the boring bar.

A device for the precise angular positioning of tool-holders suitable for CNC machines, in particular tool-holders (10) motorised or non-motorised, comprising a front part (12) and an opposite rear part (14) and suitable to perform angular machining on multi-spindle and single-spindle CNC lathes, on transfer machines, milling centres and machine tools which perform machining by chip removal, comprises a plug (18) cooperating with a pair of pins (28), (30) arranged orthogonally relative to said plug and adjustable in rotation. Each of the pins (28), (30) comprises an offset cylindrical central portion (32), forming a cam which, by rotating, interacts with said pins to achieve said precise angular positioning of the tool-holders (10).

An automatic lathe includes a main spindle that rotates a workpiece about a shaft center, a cutting tool that processes the workpiece, a feeder that moves the cutting tool, an input receiver that receives inputs regarding an eccentric distance and a radius, and a controller that controls the movement by the feeder such as to set a virtual circle having a radius of the distance, to set an offset virtual circle having a center at a position where a center of the virtual circle is offset from the shaft center of the workpiece in the radial direction of the workpiece by the radius, and to move the cutting tool along an circumference of the offset virtual circle in relation to a rotation of the workpiece by the main spindle. A hole is processed, which has the radius at a position away from the shaft center by the distance.