Abstract: An improved female mold is used in conjunction with a heated male mold for press bending glass products, such as vehicle windshields. The female mold is made of a material having thermal expansion properties equivalent to those of the corresponding male mold, preferably ceramic and most preferably the same ceramic material as the male mold. Additionally, the female mold is preferably heated so that the glass sheet to be press bent is contacted by heated surfaces on both sides.

Abstract: An improved male mold for press bending sheets of glass includes, as heating elements, heating wires which are disposed in the male mold in a manner which conforms to the outer surface of the male mold. These heating wires provide a more uniform temperature profile over the pressing surface of the male mold, thus more uniformly heating sheets of glass. Additionally, a method is provided of making a male mold for press bending sheets of glass with such conformal heating elements.

Abstract: A closed loop control system for a hydraulically actuated glass sheet press bending platen. Flow of fluid supplied to the cylinder operating the press platen is controlled through a servo solenoid valve. A linear motion transducer associated with the platen and sends appropriate signals to a programmable motion controller. The motion controller controls a position module operatively coupled to a servo solenoid valve which regulates the flow of hydraulic fluid from a pump to the cylinder. The motion controller utilizes data from the linear motion transducer for making necessary corrections to insure that the platen cycles precisely in accordance with a predetermined program. In a second embodiment of the invention, the closed loop control system for the hydraulically operated platen is combined with a precision control of a variable speed glass sheet conveyor means for improved registry of the glass sheet being bent with the platen member.

Abstract: A process and apparatus for conveying formed, heated glass sheets from a glass forming station, through a glass tempering station, to a lehr, utilizes a shuttle ring conforming in outline and elevation to the marginal edges of the glass sheet. The shuttle ring receives the glass sheet from the lower shaping mold, by the relative downward vertical movement of the lower shaping mold away from the upper shaping mold. The glass sheet thus deposited on and supported by the shuttle ring is transported through the tempering station to the lehr.