MILL FOR LENGTHWISE EXPANDING OF AXIALLY SYMMETRICAL SHAPES Russian patent published in 2003 - IPC

FIELD: plastic working of cold metal, possibly expanding parts with axially symmetrical cross section such as parts having splines, teeth, polygonal, cylindrical, cone parts and parts with shaped surface. SUBSTANCE: mill includes housing; stocks secured to housing; clamping centers; rotation mechanism with stopper device in the form of rotary plate having stops and mounted in one of clamping centers; stationary plate with stops mounted on inner surface of cylinder; head mounted in quick-release traverse bar secured to body of power drive unit. Expanding rollers are mounted with possibility of rotation on axles in said head. There are radius grooves on end surfaces of expanding rollers for engaging with rigid stops arranged in head body and turnings for placing coil springs whose one ends are secured to expanding roller and whose other ends are secured to axle. Before mounting in head, expanding rollers are rigidly fixed on axle by means of fixing member, for example in the form of rectangular rod with cylindrical end. Rectangular portion of fixing member engages with groove on end of expanding roller; cylindrical end of fixing member is placed in opening of axle. Each fixing member in the form of rectangular rod with cylindrical end is arranged in such a way that its rectangular portion is placed in radial groove on end of expanding roller and its cylindrical end is placed in opening of axle. In lid of head there are windows for mounting fixing members after assembling head. On end of rectangular portion of fixing member there is thread for demounting fixing member after assembling head. Each fixing member has cutout directed to side of coil spring. EFFECT: improved design of mill allowing to expand high-quality axially symmetrical shapes, lowered metal consumption for making shapes. 5 cl, 6 dwg