US1505584A - Method of drawing sheet glass - Google Patents

Description

Aug. 19, 1924. 1,505,584

H. S. CAMPBELL METHOD OF DRAWING SHEET GLASS Filed Feb. 12, 1919 atented Aug. 19, 1924.

UNITED STATES HUDSON s. owl-BELL, or onnnxsnune, wEsr vnmmriei.

METHOD or DRAWING SHEET GLASS.

Application filed February 12, 1919. Serial No. 276,691. I

To all whom it may concern:

Be it known that HUDSON S. CAMPBELL, a citizen of the United States, a resident of Clarksburg, in the county of Harrison and State of West Virginia, has invented a new and useful Improvement in Methods of- Drawing Sheet Glass; and he does hereby declare the following to be a full, clear, and exact description thereof.

My invention relates particularly to a method of drawing glass in sheet form.

The object of my invention is to provide a method of drawing sheet glass, in which the drawing operation is a continous one and the glass is so supported in the operation as to keep it spread or taut, thus insuring a perfectly flat piece of glass while, at the same time provision is made for severing the glass in sheets of any suitable length as it is being formed.

In the accompanying drawing, I have illustrated apparatus suitable to carrying out my improved method in which Figure l is a view of a portion of a suitable furnace with a forehearth or a dog-house extension shown partly broken away with the drawi g apparatus arranged therein; Figure 2 is a section on the line 2-2 on Figure 1; Figure 3 is an enlarged view showing the manner in which the sheet is severed, and Figs. 4, 5, and 6 are perspective views of the cutting and gripping blocks.

In the drawing the numeral 2 designates a suitable furnace with the forehe-arth or dog-house 3 into which the glass 2 flows from the furnace 2. In order to cut 05 to some extent, the heat of the furnace from the area from which the glass sheet is drawn, any suitable shielding device 4 may be em lo ed.

p be upper and lower shafts 5 and 6 are arranged in pairs parallel to each other in suitable bearings and mounted on said shaft at each end thereof are the sprocket wheels 7 and 8 respectively.

Chains 9 and 10 are mounted on said sprocket wheels and power is provided for driving said chains in opposite directions,

as indicated by the arrows Fig. 1. The links of the chain are provided with gripping blocks 11, with the serrations or teeth, 12, formed therein as shown Fig. 6.-

At intervals on the chains 9 are the bars 13, which extend from one chain to the other, said bars having the fiat-faced portions 14 and the serrated portions 15.

,The chains 10 carry the bars 16 which extend from one cham to the other, and said bars are provided with the knife 17, and the serrations 17*. The bars 13 and 16 are so arranged that as the said chains travel, said bars will come into register with each other at the point in line with the lower shaft 6, or before said bars leave the peripheries of the lower sprocket wheels, the knife like edge 17 co-operating with the fiat face 14 of the bar, 13, to sever and at the same time grip the lastic glass as clearly indicated in Fig. 3. y having these bars co-operate in this way before leaving the peripheries of the lower sprocket wheels, a resistance is afiordedto take up the thrust caused by the severing and gripping of the glass at this point, as will more fully here,- inafter appear.

In carrying. out my improved method by the apparatus above described, the glass is first lifted from the supply of molten glass in the forehearth 0r dog-house by lowering a suitable bait and lifting the glass up between the chafts 5 and 6 until it is in a position for the bars 13 and 16, which by coming in contact with each other, savers and grips the succeeding sheet simultaneously at any point desired below the original bait used for starting the draw, and the serrations on the lower part of the bars 13 and 16, which extend clear across the sheet, entering into the plastic glass, makes the grip for the continuous draw. This preliminary lifting of the glass by the bait has not been illustrated, as there are many dif ferent forms of baits suitable for this purpose, and this preliminary step forms no part of my present invention.

As soon as the gripping bars 13 and 16 take hold of the sheet the glass will be kept moving or continue to be drawn by the operation of my apparatus and the sprocket wheels being geared together, the serrations in blocks 13 and 16 act to replace the bait and operate as a bait until such time as another set of said bars '13 and 16 come into place or contact with the sheet of glass which is being drawn. The chains 9 and 10 and side gripping blocks 11 carried thereby will travel at a uniform rate of speed and said blocks will be of a size only to extend for about an inch or so on both edges of the sheet, the intervening glass will be smooth and even and the drawing operation will be continuous, as long as the sprocket in this manner, kee perfectly flat sheet is thus insured.

The sheet thus formed is severed and simultaneously the succeeding sheet regripped, while soft or plastic and this is done by the knife-bars 16, co-operating with the supporting bars 13. This severing accordingly takes place down adjacent to the point of draw and the knife block and supporting blocks are timed to come into register with each other, preferably before the blocks leave the peripheries of the lower sprockets, or in line with the shafts, so that the blocks are supported against thrust during the severing and re-gmpping operation. This is clearly indicated in Figures 1 and 3 of the drawing where the knife edge 17 is shown as having forced its way into the plastic sheet of glass and before the glass has hardened or set. This knife edge 17 cooperates with the flat face 14 of the block 13 and the knife, b pressing against the .smooth face 14 of the block 13 will sever the glass at this point, and by reason of the serrations, 15 and 17- on blocks 13 and 16, the grip on the succeeding sheet will be had below the point of severing, simultaneously with the severing and the glass will keep on traveling upward until the next set of severing and gripping bars 13 and 16 come into play to cut off one sheet and support the next sheet and continue its'upward movement, thus making a continuous draw. This is made possible by the fact that the severing and gripping takes place at all points along the width of the sheet at the same time.

By the expression severing the glass as used both in the specification and claims, I mean either the complete separation of the glass from the main body or such a separation as will leave the sheet connected to the main body only by a thin film, so that when the sheet passes above the apparatus, by bending the sheet at the point of severance, the sheet will be detached from the main body of glass.

By my invention I provide for the drawing of sheet glass continuously and for the severing and simultaneously gripping of the succeeding sheet of the glass while it is still in its plastic or soft condition, thereby forming sheets of any desired length, and as the glass is only gripped along its edges 1 and at its top edge during the drawing, only the portions so gripped is waste. As the intervening glass does not come in contact with any rolls or supporting device, the surface of the glass has a very high finish and contains none of the defects due to the flattening operation required in the manufacture of glass by the cylinder process, which operation mars, to a more or less degree, one or both surfaces of the glass. The glass is formed of any desired width or thickness and when introduced into the annealing oven it comes out with a perfectly annealed fire-polish on both sides of the sheet due to the fact that the glass during this formation is not subjected to any rolling or flattening operation which will cause an uneven temperature condition due to defects caused by such rolling or flattening, and hence an imperfect annealing.

I prefer to make the bars 13 and 16 as well as the gripping blocks 11 of carbon such as set forth and claimed in an application filed by me on the 8th day of August, 1919, Serial No. 316,109.

What I claim is:

1. The method of forming sheets of glass consisting in drawing the sheet continuously from a bath of molten glass, severing the glass, simultaneously gripping the succeeding sheet along its top edge, and gripping its side edges below the point where the first gripping occurs to keep it spread taut.

2. The method of forming sheets of glass consisting in drawing the sheet continuously from a bath of molten glass, severin the glass, gripping the succeeding sheet simultaneously with the severing Just below the point of severing, and gripping the side edges of the sheet at intervals to keep the sheet taut, all while in a plastic condition.

In testimony whereof, I, the said HUDSON S. CAMrBELL, have hereunto set my hand.

HUDSON S. CAMPBELL.

Witnesses:

C. W. VANNoR'r, CHARLES Lone.

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