US1570695A - Glass-drawing apparatus - Google Patents

Description

Patented Jan. 26, 1926.

UNITED STATES PATENT OFFICE- WILLIAM L. MONRO, OF PITTSBURGH, PENNSYLVANIA, .ASSIGNOR TO WINDOW GLASS MACHINE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

GLASS-DRAWING APPAATUS.

Applipation led November 6, 1922. Serialy No. 599,236.

To all whom it may concern: f

Be it known that I. WILLIAM I1. MoNRo, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement inGlass-Drawing Apparatus, of which the following is a full, clear, and exact description.

This invention relates to glass drawing apparat-us, and more particularly to the Lubbers venting system used in the drawing of glass cylinders. While the original Lubbers system of venting was effectualin reducing bumps or pulsations to within commercial flattening limits, this invention still further reduces such pulsations, and is effective to produce a more uniform cylinder under varying operating conditions.

In the co-pending application of Monro, Clark and Pierce, Serial No. 231,332, filed April 29, 1918, there is shown a venting system in which a jet of air is forced into a venting chamber of larger cross sectional area. than the jet, thence through a long enclosed conduit to the cylinder. I have discovered that pulsations are still further re* duced or avoided if the venting chamber is `moved to a position adjacent the bait.

Another 'distinguishing feature of the present invention is the location of the venting opening with respect to the jet opening. I have found that the action of the vent is rendered much more sensitive if the vent opening extends at least as far as the plane of the air jet opening.

In the accompanying drawings, illustrating the preferred embodiment of my invention,

Figure 1 is a view, partly broken away, showing my improved vent applied to the usual form of blow-pipe;

Figure 2 is a detail sectional view of a portion of Figure 1;

Figure 3 is a section, to reduced scale, on the line III- III of Figure 2;

Figure 4 is a view corresponding to Fig ure 3, but showing a two-hole form of vent;

Figure 5 is a detail sectional view showing a slightly modified form of apparatus; and

Figure 6 is a detail sectional View showing another modification.

In the preferred embodiment of the invention, air is supplied from an air line, not shown, through the usual ball connecd tion 2 of a blow-pipe 3, thence through a restrictor 4 into a venting chamber 5. The venting chamber 5 is located adjacent the drawing bait 6. v

A venting opening 7 is provided in the side wall of the chamber 5. 7 may be of any shape, but it should extend at least as far as, and preferably be tangent to, or terminate in, the plane of the jet openlng. I have found that the sensitivity of thevent is greatly increased by such an arrangement. The form shown in Figure 5 has also given good results. In this form the restrictor 4 projects slightly into the chamber. While the best results are apparently attained when the vent opening terminates in the plane of the jet opening, it may be -shifted slightly upwardly without materially affecting the sensitivity. In other words, the jet opening should be at or below the upper edge of the vent opening. l

The effect of the restrictor 4 is to cause the air to enter the chamber 5 in jetform. This results, I believe, in the formation of regions of sub-atmospheric pressure adjacent the chamber walls lateral to the air stream, as indicated by dotted section lines in Figures 2, 3 and 4. The space thus taken up I have designated generally as a pocket, since there is a partially enclosed space back of the current of air moving through the chamber. This tendency to create a region of reduced pressure is of course obviated on one side by the vent opening, where atmospheric pressure will always tend to prevail. These two conditions, I believe, cause the air stream to be drawn slightly out of line toward the pocket, and any variation in pressure in the cylinder is reflected in the swaying of the air stream back and forth. This swaying causes greater or less air How through the vent opening 7 dependin on whether the air stream sways towar or away from the vent, and serves to very accurately regulate the cylinder pressure. I do not, however, limit myself to this theory.

In Figure 4 a modified form of apparat-us embodymg two vent openings 7 is shown. The vents are so disposed with re's ect to the chamber wall that each has a pocet opposite it. Such a form has" been found satisfactory in gractice, whereas Aother forms, in which one The openingY 'ol'er was placed opposite the' other, thus eliminating the pocket, have not been satisfactory.

In Figure 6, an air supply pipe 3a of smaller cross sectional area than the chamber 5 is used to give the jetaction which I secure in the preferred form by the restrictor t.

While I have shown the preferred form of my invention, it will be understood that it is not limited to the illustrated details, but may be embodied in other constructions without departing from the spirit of the invention or the scope orn the following claims.

I claim:

l. In apparatus for drawing glass cylinders, a bait, a. chamber adjacent the bait, and a. nozzle of smaller cross sectional area than the chamber adapted for the discharge of air in jet form through the chamber and into the bait, the chamber havino' a substantially continuous wall at one sizde of the path of said air jet and having an opening opposite such wall, substantially as described.

2. In apparatus for drawing glass cylinders, a chamber through which air is supplied to the cylinder being drawn, the chamber having an air inlet opening which is of smaller cross sectional area than the chamber and adapted to deliver air in jet form, the chamber also having a venting opening extending at least as far as the plane of the air inlet opening, substantially as described.

3. In apparatus for drawing glass cylinders, achamber through which air is Vsupplied to the cylinder being drawn, the chamber having an air inlet opening which is of smaller cross sectional area than the chamber and adapted to deliver air in jet form, the chamber also having a venting opening terminating in the plane of the air inlet opening, substantially as described.

4. In apparatus for drawing glass cylinders, a bait and a chamber immediately adjacent thereto through which air is supplied to the cylinder being drawn, the chamber having an air inlet opening which is of smaller cross sectional area than the chamber and adapted to deliver air in jet form, the chamber also having a` venting opening terminating in theplane of the air inlet opening and having a pocket opposite the venting opening, substantially as described.

In testimony whereof I have hereunto set my hand.

WILLIAM L. MONRO.

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