DEVICE FOR COIL SPRING PREDEFORMATION Russian patent published in 2017 - IPC B21F35/00 

FIELD: machine engineering.

SUBSTANCE: invention comprises a cage with a cylindrical cavity, two detachable lids with an axial bore, which are adapted to be fixed to the cage, a cylindrical core coaxially disposed in the cage and arranged to receive a spring in the cavity between the cage and the core, and rods of circular cross section with "keyed" heads, rigidly connected to the core and arranged to be located in the lids apertures. The cylindrical surfaces of the cage and core cavity are made with threaded grooves to accommodate the coils of the compressed spring, with a possibility of spring compression by the core by its limited longitudinal movement when subjected to force. The cage is made collapsible along the center line and consists of two halves, which are able to be connected and separated by means of keys and keyways located on the mating surfaces of the cage using a fixing ring.

EFFECT: strength characteristics of the spring are increased.

11 dwg