DEVICE FOR SPRING CONTACT TESTING AT MAXIMUM LOAD Russian patent published in 2011 - IPC B21F35/00 

FIELD: process engineering.

SUBSTANCE: invention relates to production and testing of springs, particularly, to increasing spring service life by spring hardening. Proposed device comprises top die with ball surface, bottom stationary plate, top insert with ball surface in contact with top die ball surface, bottom die arranged on said plate, rectangular guide supports rearranged to spring OD and secured to bottom stationary plate with the help of radial T-like grooves made thereon. Said inserts have screw surface repeating shape of spring extreme coils and provided with grooves deep to, at least, half the spring coil diametre, and grooves to accommodate rectangular guide supports to lock spring extreme coil end faces.

EFFECT: locking spring extreme coils in hardening.

3 cl, 4 dwg