Patent ID: 9643872
Date: 2017-05-09
CPC Classifications: C03B

Claim:
1. A roll forming apparatus comprising: a glass feed device for supplying a stream of molten glass; and at least one forming roll being spaced from a forming body to define a glass forming gap between the forming roll and the forming body for receiving the stream of molten glass to form a glass ribbon including a formed thickness, wherein the forming roll comprises a working zone portion comprising a working zone surface for engaging the stream of molten glass, the working zone surface including a substantially constant length extending parallel to a rotation axis of the forming roll with the working zone surface circumscribing the rotation axis of the forming roll, wherein the forming roll includes a first thermal resistance boundary extending towards the rotation axis of the forming roll at a first acute angle relative to the rotation axis of the forming roll and a second thermal resistance boundary extending towards the rotation axis of the forming roll at a second acute angle relative to the rotation axis of the forming roll, the first acute angle facing away from the second acute angle, and the working zone surface being defined between the first thermal resistance boundary and the second thermal resistance boundary, and wherein the first thermal resistance boundary extending at the first acute angle and the second thermal resistance boundary extending at the second acute angle provide the working zone portion with a circumferential dovetail portion between the first thermal resistance boundary and the second thermal resistance boundary, and the circumferential dovetail portion includes a trapezoidal cross-sectional portion flared in a radial direction extending away from the rotation axis of the forming roll.