Abstract: A heater has a heat resistant, thermally and electrically insulating tube having an elongated opening through a wall of the tube and extending along at least a portion of the tube, and a heating element positioned within the tube and extending along at least a portion of the opening. A first portion of a section of the element extending along the opening is exposed and a second portion of the section of the element extending along the opening is shielded by the tube. In one particular embodiment of the invention, the tube is a cylindrically shaped aluminum oxide tube, the heating element is a nichrome wire coil, and the elongated opening is a slot having a constant width which extends between opposing ends of the tube.

Abstract: A heat softened glass sheet is shaped between a contoured upper mold and a flexible lower ring mold. The flexible shaping surface of the lower mold has a generally flat surface configuration as it initially contacts and lifts the peripheral portions of the glass sheet off a series of conveying rolls. The lower mold continues to bias the glass sheet against the upper mold and deforms to substantially compliment a corresponding peripheral portion of the contoured upper mold.

Abstract: Edge grinding cut glass sheets by engaging the moving edge of a cut glass sheet with a rotating edge grinding wheel having blocky diamonds in a concentration not exceeding 20 embedded in a matrix.

Abstract: A bit for a core drill of the type for drilling a chamfered hole in an article has a dynamic cooling fluid flow directing element for cooling the bit and article surfaces during drilling and chamfering of the article.

Abstract: This invention relates to applying a protective composition to the vicinity of a scored region of a glass sheet. The scored region is weakened and develops vents as a result of the scoring. Such vents are likely to develop breakage when the glass sheet is subjected to a thermal treatment associated with tempering. The application of the protective composition is made before the glass sheet is subjected to thermal processing by heating to above its strain point followed by rapid cooling below its strain point. The protective composition flows at a lower temperature than the glass sheet to which it is applied and is capable of healing the scored region during the thermal treatment to which the glass sheet is subjected after the application of said protective composition, thereby reducing the tendency of a vent to develop into glass breakage during said thermal treatment.

Abstract: A tong supporting carriage is provided with an elongated tong support member having elongated slots with low friction bearing means for supporting in free sliding and rotating relation a vertical rod having a clevis attached to its lower end. A lever arm having tongs suspended freely on tong suspension points on opposite sides of said clevis is attached to the clevis intermediate its ends. When two pairs of tongs are used to grip a glass sheet to be bent about a vertical axis of bending, the tong suspension points move with the tongs gripping localized portions of the upper edge of the glass sheet and pivot the vertical rod, which slides longitudinally toward the other vertical rod as the distance between points subtended by the vertical rods on the glass sheet decreases as the glass sheet bends about a vertical axis. Kinking of the glass in the vicinity of the tong gripping points is thus minimized.

Abstract: In a glass sheet heating furnace where the glass sheets are supported by edge gripping tongs, means to heat the tongs independently from the heating of the glass sheets is provided so as to reduce the frequency of tong vents in the glass sheets without distorting edge portions of the glass sheets.

Abstract: When bending glass sheets to a curvature including a line of sharp bending, damage to the glass surface caused by sliding of the glass relative to the press surfaces is reduced by employing a hinged shaping member having offset hinges.

Abstract: A wheel having a plurality of spaced grinding pads is rotated about a vertical axis and displaced toward a glass sheet rotating in a horizontal plane to grind a rabbet in the edge of the glass sheet. The spaced grinding pads reduce frictional heat and provide periodic spacings between the glass sheet and wheel to pass a coolant therebetween to eliminate thermal damage to the glass edge.

Abstract: When glass sheets are bent to "V" shape by press bending and electrical current is used to provide localized heating along the intended line of a sharp bend, it is necessary to insulate the glass electrically from ground. This is done according to the present invention by providing the pressing molds that engage the glass with covers of electrical insulator material, such as fiber glass, and by incorporating in the glass suspending means or tongs a length of electrical insulator material sufficiently long to effectively insulate the metal tongs that engage the glass from the tong suspension carriage which is grounded and to avoid electrical arcing. The detailed tongs construction incorporating a member of an electrical insulator material of sufficient length to insulate the conductive glass sheet portion from a grounded tong supporting carriage and to avoid arcing therebetween is also part of the present invention.

Abstract: Heat-softened glass sheets may have sharp bends imparted thereto by pressing between complementary molds when preceded by localized heating along the intended line of the sharp bend. The localized heat is applied along the line by means of electrical resistance heating through the glass immediately prior to the pressing step.