Patent ID: 7958748

Claim:
An isopipe for use in a fusion process for the manufacture of sheet glass from molten glass in which a compressive load is applied to the isopipe, comprising: a refractory body comprising: a proximal end configured for application of at least a portion of the compressive load; a distal end configured for application of at least a portion of the compressive load, an upper portion, wherein at least a portion of said upper portion defines a collection trough configured to receive the molten glass, a root portion opposed to the upper portion, and outer surfaces which extend between the upper portion and the root portion, wherein said outer surfaces are angled inward to intersect at said root portion wherein the refractory body further defines a cavity positioned between the upper portion, the root portion, and the outer surfaces that extends along a longitudinal axis between the respective proximal and distal ends, and wherein a cross-sectional area of the cavity varies along the longitudinal length of at least a portion of the cavity, wherein the cavity has a lower surface, wherein at least a portion of the lower surface has a curved shape in the plane of the longitudinal axis, and wherein a center portion of the lower surface is spaced downwardly away from the longitudinal axis of the refractory body relative to the respective ends of the cavity.