Differential thermal treatment of glass objects

Claim 1

A PROCESS FOR SUBMITTING A GLASS ARTICLE, IN PARTICULAR, A GLASS SHEET TO A TEMPERING OPERATION IN WHICH A SELECTED PART OF THE GLASS ARTICLE IS TO BE OF LESS TEMPER THAN OTHER PORTIONS OF THE GLASS ARTICLE, WHICH CONSISTS IN COATING SAID SELECTED PART OF THE GLASS ARTICLE WITH A SUBSTANCE ADHERING TO THE GLASS SURFACE AND HAVING HEAT-REFLECTIVE PROPERTIES CAPABLE OF CONTROLLING THE CONDITIONS OF THE HEAT EXHCANGE BETWEEN SAID ARTICLE AND THE THERMAL SOURCE, HEATING SAID ARTICLE AND THE THERMAL SOURCE, HEATING SAID ARTICLE THUS COATED AT SUCH A RATE AS TO BRING THE UNCOATED PARTS TO A TEMPERATURE SUITABLE FOR TEMPERING WHILE SAID COATED PART IS AT A REDUCED TEMPERATURE RELATIVE THERETO, RAPIDLY CHILLING SAID COATED ARTILCE AND THEN REMOVING SAID COATING FROM THE ARTICLE.