Abstract: A tunnel furnace composed of modular sections, each modular section comprising horizontal and mutually parallel openings occupying the width of a heat treatment enclosure, the openings being beneath the top of a conveyor and adjacent each other in a direction parallel to the direction of travel of the conveyor with each opening extending perpendicular to the direction of travel, such that each opening gives out a sheet of ascending gas, a collecting slot formed in an upper wall of the heat treatment enclosure extending horizontally, mutually parallel, perpendicular to the direction of travel of the conveyor and extending the width of the enclosure, such that the slot collects the sheet of ascending gas, temperature adjusting devices for maintaining the temperature of the collected gas for the module, a circulating fan for accepting the collected gas and circulating the gas via a gas circulation path to the openings after passing through the temperature adjusting devices and a regulating device for controlling

Abstract: A conveyor apparatus for receiving and transporting cylindrical stock or articles past work stations includes a plurality of rollers disposed along spaced-apart parallel axes. The rollers are driven through one-way or overrunning clutches and rotate cylindrical stock disposed between adjacent pairs of rollers. At a work station, a moving member such as a belt engages the stock and rotates it at a speed higher than the speed imparted to it by the rollers. The overrunning clutches release the conveyor rollers and rotate with the stock at a correspondingly higher speed. The constant, non-slipping contact between the rollers and stock minimizes such difficulties as scoring of the stock and significantly improves product quality and appearance.

Abstract: A lehr for heat treating glass articles is assembled from a series of modules to define an elongated insulated tunnel. A belt conveyor extends throughout the tunnel for moving articles from one end to the other. Duct work connection between the tunnel and the ambient air and associated heating and blower means establish heating, tempering and cooling zones respectively within the lehr in the direction of conveyor movement. Temperature sensors adjacent both flights of the conveyor are linked with a control panel to permit establishment of any desired temperature curves.

Abstract: Hot glass panes are displaced without sagging through a treatment station, such as an oven, on a roller grate which is linearly reciprocated while the rollers of the grate receive a translatory angular velocity component and an angular oscillation so that the velocity at a glass pane relative to the traveling grate is R.multidot..omega..sub.osc +R.multidot..omega..sub.trans, where R is the radius of the rollers at a point of contact with the pane, .omega..sub.osc is the angular oscillation velocity component of the roller displacement and .omega..sub.trans is the angular translatory component.

Abstract: A method for the prevention of the curving of glass sheets in the roller-equipped furnace of a horizontal tempering plant utilizes a substantially turbulent air flow over the upper surface of the glass sheet for intensifying the convection heat action applied to the upper surface of the glass sheet. The furnace is fitted with perforated pipes which are connected to a source of compressed air for blowing horizontal air jets above the upper surface of the glass sheet.

Abstract: A traveling grate for hot glass prevents sagging of the glass by displacing the grate at a velocity different from the angular velocity imparted to the grate rollers in the opposite direction so that the translatory velocity imparted to the glass is an algebraic summation of the grate velocity and .omega.R where .omega. is the angular velocity of the rollers and R is the radius thereof.

Abstract: The present invention was developed to provide an improved process for retaining the substantially pristine state of glass articles, particularly thin-walled, lightweight glass containers.

Abstract: Glass lenses or lens blanks, containing all the ingredients necessary to produce phototropic or photochromic behavior, are treated in a conventional production furnace to produce a locally variable heat treatment, wherein at least one portion thereof is raised to a temperature exceeding the glass strain point but not the softening point, and other portions are heated to variable temperatures decreasing from the strain point. The treatment causes development of phototropic or photochromic behavior only in those portions of the lenses or lens blanks exposed to the temperature above the strain point.

Abstract: Glass lenses or lens blanks, containing all the ingredients necessary to produce phototropic or photochromic behavior, are treated in a conventional production furnace to produce a locally variable heat treatment, wherein at least one portion thereof is raised to a temperature exceeding the glass strain point but not the softening point, and other portions are heated to variable temperatures decreasing from the strain point. The treatment causes development of phototropic or photochromic behavior only in those portions of the lenses or lens blanks exposed to the temperature above the strain point.

Abstract: A method of treating ophthalmic quality lenses or lens blanks that produces a reversible progressive local variation in phototropic behavior with a continuous variation in transmissivity. The lens or lens blank is composed of a potentially phototropic glass containing all the necessary ingredients including uniformly dispersed silver halide particles therein to develop a phototropic behavior during the heat treatment of the present method. The steps of the present method include mounting the lens or lens blank in carrier means, heating the lens or lens blank thus mounted in a heat treatment furnace at a temperature sufficient to develop the phototropic behavior of the potentially phototropic glass. Characteristically the required heat treatment temperature to develop this phototropic behavior is one which exceeds the strain point of the glass but not the softening point thereof.

Abstract: The invention achieves local variation, or a continuous gradation, in photochromic or phototropic properties across the face of glass lenses and lens blanks, especially those of ophthalmic quality. The lenses and lens blanks contain all those ingredients required to produce photochromic or phototropic behavior. They are exposed to a locally variable temperature field or environment, in such manner as to, in at least one portion of the lens or lens blank cause the temperature therein to exceed the strain point but not the softening point of the glass. In other portions of the lens or lens blank the temperature is below the strain point, thus causing development of phototropic or photochromic behavior only in those portions of the lens or lens blank exposed to the temperatures above the strain point.

Abstract: A method of thermally treating glass products in which the products are conveyed through a number of heating zones and/or cooling zones of a tunnel furnace and are heated and cooled, respectively, by means of an airflow maintained in each zone in a direction transverse to the direction of transport; according the invention, the velocity of the airflow increases gradually both in the heating zones and in the cooling zones; for that purpose, two perforated partitions having gradually increasing flow apertures for the airflow are provided in each zone.

Abstract: A method of and apparatus for controlling the temperatures of glass sheets moving bodily through a furnace by automatically varying the heat exposure time of the sheets in the furnace in accordance with temperature variations from a desired level detected in heated sheets exiting the furnace.

Abstract: In a furnace for heating sheets of glass wherein the glass is supported on a layer of gas, hot furnace gases are internally recirculated by means of an air flow amplifier utilizing the Coanda effect. A portion or all of the thermal energy may be efficiently supplied by electric heating.

Abstract: In a furnace for electrically heating sheets of glass wherein the glass is supported on a layer of gas, hot furnace gases are internally recirculated by gas flow entrainment means, preferably an air flow amplifier utilizing the Coanda effect. Air supply tubes are electrically heated and arranged over the glass to provide the furnace with thermal energy.

Abstract: The invention achieves local variation, or a continuous gradation, in photochromic or phototropic properties across the face of glass lenses and lens blanks, especially those of ophthalmic quality. The lenses and lens blanks contain all those ingredients required to produce photochromic or phototropic behavior. They are exposed to a locally variable temperature field or environment, in such manner as to, in at least one portion of the lens or lens blank cause the temperature therein to exceed the strain point but not the softening point of the glass. In other portions of the lens or lens blank the temperature is below the strain point, thus causing development of phototropic or photochromic behavior only in those portions of the lens or lens blank exposed to the temperatures above the strain point.

Abstract: A glass tempering system including a roller hearth furnace that has a conveyor with elongated rollers extending through an elongated heating chamber of the furnace and outwardly through elongated slots in the sides of the furnace so as to be supported on drive belts which are slidably driven along support surfaces to thereby frictionally drive the rollers and convey glass sheets over the rollers through the heating chamber. The furnace is of a modular construction and includes upper and lower housing portions with inner layers of refractory material that define the heating chamber. Flanges of the refractory material cooperate to define the elongated slots at the sides of the furnace. Heat seal arrangements extend between the refractory flanges and the conveyor rollers to mitigate heat flow from the furnace during use. A first electric motor drive mechanism drives belt sheaves that receive the drive belt at the end of the furnace where glass enters the heating chamber.

Abstract: This disclosure relates to a method and apparatus for annealing glassware by passing the ware continuously through a tunnel in which the application of heat and recirculation of the gaseous treating medium is regulated to establish and maintain independently controllable heating and cooling zones. An endless perforated conveyor passes from end to end of the tunnel and the ware is placed on the conveyor in alignment with and beneath a jet-like blast of the treating medium internally and externally of the ware simultaneously to subject all of the ware to uniform treatment in minimum time. The treating medium in the heating zones of the tunnel is recirculated and furnace pressure and temperature is regulated by circulating fans and by dampers between the furnace chambers with the outside atmosphere.