Patent ID: 9249525
Filing Date: 2016-02-02
CPC Classification: C30B,H05B,Y10T

Claim Text:
1. A flat, ring-shaped resistance heater suitable for supplying heat to a growing single crystal, comprising first and second flat rings, each ring having an outer circumference and an inner circumference defining respective outer and inner edges, the edges optionally rounded; the outer and inner optionally rounded edges connected by annular planar surfaces, wherein each ring is interrupted by a ring gap, and the upper and lower rings are spatially and electrically separated from each other except at a loop portion proximate a ring gap of one ring, such that a flow direction of electric heating current in the first ring is opposite the flow direction of electric heating current in the second ring, the annular planar surfaces forming on each ring an outward annular planar surface facing away from the other ring, and an oppositely facing annular planar surface facing toward the other ring; a plurality of insulative ring connecting elements spaced circumferentially along the annular planar surfaces of the first and second rings, the insulative ring connecting elements securing the upper and lower rings together but spatially separated and restricting movement of the upper and lower rings towards each other or away from each other; at least one insulative end connecting element proximate said loop portion and located on the annular planar surfaces of the first and second rings, securing the first and second rings to each other in an insulative fashion; a first current lead attached to said first ring proximate the gap in the first ring; a second current lead attached to said second ring proximate the gap in the second ring; wherein the first and second current leads are secured to each other by at least one insulative current lead connecting element which restricts movement of said first and second current leads towards or away from each other in the presence of an external magnetic field, and wherein all insulative connecting elements are composed of an insulating material or a material which provides a high impedance to the flow of electrical current.