AUTOMATIC MACHINE FOR EXPANDING RINGS AND METHOD FOR MAKING BANDAGES Russian patent published in 1999 - IPC

FIELD: plastic metal working, namely manufacture of ring-shaped articles, possibly bandages with complex-shape cross section. SUBSTANCE: ring expanding automatic machine with vertical expansion plane, outer driven roll having stationary rotation axis and radially moving inner expanding mandrel includes movable centering rollers with locking device, mechanism for radially moving inner expanding mandrel mounted on rocking lever for moving mandrel axis along circle. Relation of radius of said circle to value of working stroke of mandrel is no less than 25:1. Expanding mandrel has hinged support mounted on two spindles secured to body of rocking lever and having axes parallel relative to mandrel axis. Mechanisms for charging blank and discharging expanded bandage are in the form of movable lever supports mounted in body of moving hinged support of expanding mandrel. Method for making bandages comprises steps of successively deforming ring blank at first between outer rotating roll and inner expansion mandrel at applying radial effort to mandrel and applying limitation efforts by means of two moving pressure rollers to outer portion of blank near outer roll. Then blank is deformed between working rolls at applying limitation efforts by means of two moving centering rollers arranged opposite relative to pressure rollers and at removing limitation efforts of pressure rollers. Blank is deformed at removing radial effort acting upon mandrel and it is rotated relative to three stationary supports at side of outer roll and two fixed centering rollers. EFFECT: lowered labor consumption at making bandages of enhanced quality, increased reliability of automatic machine. 5 cl, 6 dwg