# US 9,038,418 B2 · Apparatuses for manufacturing glass and methods of managing pulling forces applied to glass ribbon > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,038,418 B2 - Document ID: US9038418B2 - Status: Granted - Kind: B2 - Application number: 13/626,337 - Filed: 2012-09-25 - Published: 2014-03-27 - Granted: 2015-05-26 - Earliest claimed: 2012-09-25 - Assignees: Corning Incorporated - Applicants: Chris Scott Kogge; Gautam Narendra Kudva; Michael Yoshiya Nishimoto - Inventors: Chris Scott Kogge; Gautam Narendra Kudva; Michael Yoshiya Nishimoto - Web page: https://patentgrep.com/patent/US9038418B2 ## CPC - C03B 17/068: {Means for providing the drawing force, e.g. traction or draw rollers} - C03B 17/064: {by the overflow downdraw fusion process; Isopipes therefor} - C03B 33/0215: {the ribbon being in a substantially vertical plane} - G05B 15/02: electric - C03B 33/037: Controlling or regulating - Y02P 40/57: Improving the yield, e-g- reduction of reject rates - C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES - G05B: CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS (systems for controlling or regulating non-electric variables G05D; systems for regulating electric or magnetic variables G05F; control devices or systems insofar as characterised by mechanical features only G05G) - Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS ## Abstract Methods and apparatuses for managing pulling forces applied to a glass ribbon in a draw apparatus are disclosed. The method includes applying a front-side and a rear-side drive torque to a glass. The method further includes calculating automatically with the at least one electronic controller a front-side and a rear-side average pulling force applied to the glass ribbon and corresponding to a first time period of at least one rotation of the front-side or rear-side stub roller, respectively. The front-side average pulling force and the rear-side average pulling force are compared to establish a pulling force differential between the front-side average pulling force and the rear-side average pulling force. One or more of the front-side drive torque or the rear-side drive torque are modified to decrease the pulling force differential between the front-side average pulling force and the rear-side average pulling force. ## Claims ### Claim 1 A method of managing pulling force applied to a glass ribbon in a draw apparatus, the method comprising: applying a front-side pulling force to a front side of the glass ribbon with a front-side stub roller; applying a rear-side pulling force to the glass ribbon with a rear-side stub roller that contacts a rear side of the glass ribbon opposite the front-side stub roller; receiving with at least one electronic controller a front-side instantaneous drive torque signal indicative of a front-side drive torque applied by the front-side stub roller to the glass ribbon, wherein the front-side instantaneous drive torque signal is based on an electrical current directed to a front-side motor coupled to the front-side stub roller; receiving with the at least one electronic controller a rear-side instantaneous drive torque signal indicative of a rear-side drive torque applied by the rear-side stub roller to the glass ribbon wherein the rear-side instantaneous drive torque signal is based on an electrical current directed to a rear-side motor coupled to the rear-side stub roller; calculating automatically with the at least one electronic controller a front-side average pulling force applied to the glass ribbon and corresponding to a first time period of at least one rotation of the front-side stub roller; calculating automatically with the at least one electronic controller a rear-side average pulling force applied to the glass ribbon and corresponding to a second time period of at least one rotation of the rear-side stub roller; comparing the front-side average pulling force to the rear-side average pulling force to establish a pulling force differential between the front-side average pulling force and the rear-side average pulling force; and modifying one or more of the front-side pulling force or the rear-side pulling force to adjust the pulling force differential between the front-side average pulling force and the rear-side average pulling force. ### Claim 2 (depends on 1) The method of claim 1, further comprising graphically displaying the front-side average pulling force and the rear-side average pulling force. ### Claim 3 (depends on 1) The method of claim 1, wherein the front-side average pulling force applied to the glass ribbon is calculated based on a front-side stub roller diameter variable and the front-side instantaneous drive torque signal, the front-side stub roller diameter variable being indicative of the actual diameter of the front-side stub roller. ### Claim 4 (depends on 3) The method of claim 3, further comprising modifying the front-side stub roller diameter variable to adjust a front-side drive speed of the front-side stub roller. ### Claim 5 (depends on 1) The method of claim 1, wherein the rear-side instantaneous pulling force of the glass ribbon is calculated based on a rear-side stub roller diameter variable and the rear-side instantaneous drive torque signal, the rear-side stub roller diameter variable being indicative of the actual diameter of the rear-side sub roller. ### Claim 6 (depends on 5) The method of claim 5, further comprising modifying the rear-side stub roller diameter variable to adjust a rear-side drive speed of the rear-side stub roller. ### Claim 7 (depends on 1) The method of claim 1, further comprising modifying at least one of a front-side drive speed of the front-side stub roller or a rear-side drive speed of the rear-side stub roller to control a thickness of the glass ribbon. ### Claim 8 (depends on 1) The method of claim 1, further comprising calculating with the at least one automatic controller an intrinsic linear feed rate of the glass ribbon based on at least one of: a front-side drive speed of the front-side stub roller and a front-side stub roller diameter variable; or a rear-side drive speed of the rear-side stub roller and a rear-side stub roller diameter variable. ### Claim 9 (depends on 8) The method of claim 8, further comprising: receiving with the at least one electronic controller an extrinsic linear feed rate of the glass ribbon; and comparing the intrinsic linear feed rate of the glass ribbon to the extrinsic linear feed rate of the glass ribbon. ### Claim 10 (depends on 9) The method of claim 9, further comprising cutting the glass ribbon, wherein the extrinsic linear feed rate of the glass ribbon is calculated with the at least one electronic controller based on a length of a glass sheet cut from the glass ribbon. ### Claim 11 (depends on 9) The method of claim 9, wherein the extrinsic linear feed rate is calculated with the at least one electronic controller based on a rate of rotation of at least one slave stub roller positioned to contact the glass ribbon as the glass ribbon translates in the draw apparatus. ### Claim 12 (depends on 1) The method of claim 1, further comprising: scoring the glass ribbon with a score wheel that is synchronized to traverse the glass ribbon moving at an intrinsic linear feed rate; and determining with the at least one controller whether scoring the glass ribbon with the score wheel applies force in a down-draw direction to the glass ribbon, wherein force applied to the glass ribbon by the score wheel in the down-draw direction indicates discrepancy in the intrinsic linear feed rate from the actual linear feed rate of the glass ribbon.