Heater for ring - has ring seated over one limb of U=shaped iron core closed by yoke

摘要

The heater has an iron core located in a casing and with a primary winding wound around it. The two ends of the core project out of the casing. A short-circuiting yoke made of iron forms a closed core with the outside parts of the core. The ring being heated is placed over one of the outside ends of the core after removing the short-circuiting yoke such that it rests on the upper cover of the casing. The yoke is then replaced. The core may be U-shaped and the yoke bar-shaped and pivoted at one end to one of the projecting ends of the U-core. Several such closed core/yoke systems may be used to heat one ring. The core/yoke systems may be adjustable.