METHOD OF COARSE THREAD HARDENING Russian patent published in 2009 - IPC B24B39/00 

FIELD: engineering industry.

SUBSTANCE: invention relates to engineering industry, namely to finishing-strengthening treatment of threaded blanks with coarse pitch by method of surface plastic deformation. Circular motion is transmitted to blank and circular motion and longitudinal feed equal to thread pitch is transmitted to deforming tools. Preliminary and final thread hardening is simultaneously performed by tools for preliminary hardening and tools for final hardening correspondingly. Each of the said tools includes a disk on which there is steel spring in a form of a ring. The spring is located on the edge surface of the disk with tension. Spring coils have working section performed in a form of threaded groove of the treated thread and straight attachment section. Between working section and attachment section of spring coil there are damping parts. Spring coils are attached on disk edge surface performed in a form of a ring made of thin steel string band and installed on rubber bush on disk hub. Spring coil tops are connected between themselves by ring strongly attached on each spring coil top. The spring of tool for preliminary hardening is made of steel string band, and the spring of tool for final hardening is made of steel spring wire of round cross-section.

EFFECT: technological capabilities are extended, capacity is increased, manufacturing cost is decreased.

6 dwg, 1 tbl, 1 ex