Abstract: A method for drawing glass sheets of crystallization-sensitive glass such as borosilicate glass or glass ceramic. A melt in a vat of a glass furnace is supplied through a feed channel to a drawing chamber from which a glass sheet is drawn perpendicularly upwardly essentially across a full width of the drawing chamber. The melt in the drawing chamber is heated by at least two current-charged precious metal strips at each of the opposite sides of a drawing plane in a region of the surface of the sheet. This heating occurs in sections at each side of the drawing plans so that the melt is sectionally heated and crystallization at walls of the drawing chamber laying opposite one another at the vertical drawing plane is effectively prevented. In addition, the drawing chamber can be sectionally covered by slides.

Abstract: A method for drawing glass sheets of crystallization-sensitive glass such as borosilicate glass or glass ceramic. A melt in a vat of a glass furnace is supplied through a feed channel to a drawing chamber from which a glass sheet is drawn perpendicularly upwardly essentially across a full width of the drawing chamber. The melt in the drawing chamber is heated by at least two current-charged precious metal strips at each of the opposite sides of a drawing plane in a region of the surface of the sheet. This heating occurs in sections at each side of the drawing plans so that the melt is sectionally heated and crystallization at walls of the drawing chamber lying opposite one another at the vertical drawing plane is effectively prevented. In addition, the drawing chamber can be sectionally covered by slides.

Abstract: Inner and outer blow-moulded glass bulbs, each open at one end thereof, are positioned one inside another on an apparatus having a chuck means which holds the bulbs in a spaced apart relation. The apparatus includes pivotally moveable gripping means which engage outer surface edges of the outer bulb along the open end thereof and positively hold such surface edges against an adjacent support surface while deformation heat and force are applied to the outer bulb surfaces above such edges to selectively compress or stretch such outer bulb surfaces toward the adjacent inner bulb surfaces. Thereafter, the surfaces of the inner and outer bulbs which are in contact with one another are fused together and the open ends of the respective bulbs are sealed to one another to define a container mouth.

Abstract: A device for cutting glass for example separating a drop or portion of a plastic glass skein emerging from a feeder characterized by having two shear arms mounted for rotation in a common frame, each of the shear arms being provided with a knife at its extreme end and a device for periodically moving the arms in a pincher-like closing movement toward one another and away from one another so that the knives can execute a cutting process. The device for periodically moving includes a device for forming a periodic working cycle preferably comprising at least one cam having one segment forming a working stage of a working cycle and a second segment forming an idle stage. By varying the speed of rotation of the cam while the follower is in the second stage, a time delay between the closing of the knives can be adjusted without changing the speed of movement during a cutting stage.