US3438396A - Dual differential control valve - Google Patents

Description

April 15, 1969 w. F.JEHN i 3,438,395

DUAL DIFFERENTIAL CONTROL VALVE Filed Feb. 16. 1967 INVENTOR. WEKA/6,6 F3 df/ ,grrof :is

United States Patent O 3,438,396 DUAL DIFFERENTIAL CONTROL VALVE Werner F. Jehu, 438 T winning Drive, Dayton, Ohio 45431 Filed Feb. 16, 1967, Ser. No. 617,768 Int. Cl. FlSb 3/00; C03b 9/02 U-S. Cl. IS7-596.18 8 Claims ABSTRACT OF THE DISCLOSURE A control valve for glass-blowing apparatus comprising a sealed casing having a cylindrical ring supported in slaid casing with spaced parallel flexible diaphragms closing the opposite side faces of said ring to form an isolated pressure or suction responsive chamber between said diaphragms, A positive or negative pressure intake conduit in communication with the interior of said isolated pressure responsive chamber adapted to be supplied with positive or negative (suction) oral pressure by the glassblower. A positive pressure supply valve in said casing connected to one of said diaphragms and responsive to outward deflection of that diaphragm to supply a positive pressure into said casing and a negative or suction pressure control valve in said casing connected to the other diaphragm responsive only to inward deflection of that diaphragm for applying suction or negative pressure to the interior of said casing. A iiexible glass-blowing conduit connected in communication with the interior of said casing for supplying the said positive or negative pressure from the interior of said casing to the molten glass article being blown in isolated responsive relation to the glassblowers positive or negative oral pressures.

The invention described herein may be manufactured and used by or for the United States Government for governmental purposes without the payment to me of any royalty thereon.

Cross-references to related applications This invention is an improvement on my copending patent application for Oral Contnolled Pressure Regulator, Ser. No. 537,616, led Mar. 21, 1966.

Summary of the invention The dual differential control valve comprises means which permits the glassblower to isolate his breath from the molten glassware or article under fabrication by replacing his breath with an inert or reducing gas under sensitive control of the glassblowers oral pressure or suc- The dual differential control valve comprises means tion to protect the glassblower from harmful substances during the fabrication, such as radioactive material or mercury vapors that may be given off from the heated surfaces of his glasswork, and to protect the glasswork being blown from being contaminated by the moisture or oxygen content of the glassblowerls breath.

An important object of the invention is the provision of a supersensitive control valve structure that will deliver `'an inert gas to the molten glasswork being fabricated at substantially the same relative pressures that the glassblower applies to his glass-forming mouthpiece.

A further object includes means for supplying an isolated suction pressure to the glasswork being blown at substantially the same pressure as the glassblowers suction pressure.

A further object is the provision of a glassblowing apparatus for supplying either a positive or a negative isolated pressure medium to a molten glass article being blown under control of a glassblowers positive or suction oral pressures in which the pressure or suction for 3,438,396 Patented Apr. 15, 1969 fabrication of the molten glass article is completely iso lated from the glassblowers oral breath pressure or suction, and therefore permits the glassblower tomake full use of his skill in creating and sensing the exact pressures needed for construction of the glassware or article, and also permits him to use both hands for manipulating and forming the glassware. It also facilitates the glassblowers work in the fabrication of large volume glasswork.

Brief description of the drawings FIGURE 1 is a somewhat diagrammatic elevation view, parts being broken away to foreshorten, illustrating sa glassblowing apparatus incorporating the dual differential control valve of the invention and means for supplying positive or negative inert gas pressures to the glassblowing or forming tube and work being fabricated under direct control of the dual differential control valve.

FIGURE 2 is an enlarged detail vertical sectional view of the control valve structure of the invention, showing both valves in their normally gravity-closed position in full lines and showing the upper or positive pressure supply valve moved to open position in dotted lines to admit the positive pressure of the inert gas to the glasswork being blown.

FIGURE 3 is a vertical sectional view similar to FIG. 2 but showing the lower or suction pressure inlet valve opened by the connected lower diaphragm, by the suction or negative oral pressure of the glassblower, to create a negative or suction pressure in the glasswork being fabricated.

FIGURE 4 is a fragmentary det-ail sectional View taken about on line 4-4 of FIG. 2.

Description of the preferred embodiments Reference numeral 1 denotes a closed, leakpr-oof differential dual valve chamber or casing having a bottom closure or valve supporting plate 2. The plate 2 is secured in place by any suitable means (not shown) and adjacent the opposite side edges of the plate are spaced parallel tubular conduits 3 and 4 which extend through the plate 2 in sealed relation, extending upwardly with their upper ends curving inwardly toward each other as at 3a and 4a to support an upper or inert pressure inlet valve casing 5 which is located centrally adjacent the top of the casing 1.

The tubular conduits 3 and 4 also Xedly support an annular or cylindrical ring 6 in parallel elevated relation to the base of the supporting plate 2. The cylindrical ring 6 is supported fno-rn the conduits 3 and 4 by short tubular connections 7 and 8.

The upper end 3a of the conduit 3 opens in communication with the interior of the inert pressure valve casing or chamber 5. The supporting connection `8 for the right side of the ring 6 comprises a tubular conduit opening into the supporting conduit 4 at one end and into communication with the interior of the cylindrical ring 6, as shown.

Two thin tiexible rubber diaphragms 9 and 10, respectively, are tightly fastened to the top and bottom peripheral edges of the ring 6, thus supporting the diaphragms 9 and 16 in spaced parallel relation to form with the ring 6 an isolated leakproof chamber 11 which is connected in communication with the interior of the conduit 4. The upper end of the interior of the conduit 4 is closed.

The upper or inert pressure control diaphragm member 9 is reinforced by inside and outside discs 9a and 9b substantially as shown. The lower suction or negative pressure control diaphragm 10 is 'also reinforced by the plates 10a and 10b.

Each of the upper and lower diaphragms 9 Iand 1t) is respectively connected by the upper and lower valve stems 1-2 and 13 to the disc valves 16 and 18. The inert pressure valve disc 16 normally seats by gravity on the valve seat 15 which surrounds the inert gaseous pressure inlet opening into the interior of the casing 1, pressure being admitted into the valve chamber 5 from the pressure supply pipe 3 through the port 14.

The lower valve stem 13 extends downward from the diaphragm into a lower tubular conduit member 17 and carries a valve disc 18 which seats on an annular valve seat 19, the suction pressure passage 17C receiving the transversely extending guide pins 18a on the lower end of the lower valve stem 13.

The suction conduit 4member 17 extends downward and receives a flexible hose 17a which is connected to a suction pump 17b having a discharge outlet pipe 17d. If the glassblower does not desire to apply suction then conduit 17 must be left open to atmosphere rather than connected to the suction pump.

T-he valve stem 13 is thus stabilized in the enlarged bore or guide passage 17C at one end and by the diaphragm 10 at its upper end.

The upper end of the upper valve stem 12 is likewise stabilized by the stem guide bushing 28 which extends downward in the upper valve casing 5 as shown.

The main or supporting plate 2 has a fourth tubular conduit therethrough indicated at 21 which opens in communication with the interior of the main casing or shell 1 at its upper end while the lower end is provided with a hose connection receiving a ilexible conduit or hose 22 which is connected in communication with the molten glass manipulating and blowing tube of the glass-blower or glass-forming means 23.

The reference numeral 24 denotes a lump of molten glass on the outer end of the manipulating and blowing tube 23 at the start of the glass-blowing or fabricating operation. The inert pressure medium supply tube 3 extends downward through the plate 2 and out of the bottom of the casing 1 and is connected by a flexible pressure supply conduit or tube 25 through a suitable pressure regulator 26 of conventional design to a suitable source of inert gas under pressure, for instance supplied by a pump or container 27.

The pressure medium which is supplied by the pump or tank 27 is provided at a relatively low pressure and is preferably a dry gas such as nitrogen, carbon dioxide, argon or forming gas at a low pressure of about 2 p.s.i.

The two diagram valve members 16 and 18 'are normally seated on their respective seats 15 and 19, and are held thereon respectively by gravity, aided by positive pressure supplied in the valve chamber 5 through the conduit 3, and by the negative or suction pressure applied in the lower valve guide bushing 17 from the suction putmp 17b. The valve is used in its vertical position as shown.

The glassblowers mouthpiece or nipple is indicated `at 28 and is connected by a suitable length of flexible tubing 29 to the tube or conduit 4 projecting below the casing as seen in FIG. 1, which established the glassblowers oral pressure or suction through the short conduit 8 to the coniined and isolated space within the cylindrical ring 6 and between the spaced valve controlling diaphragm members 9 and 10.

From the above it will be observed that if no pressure or suction is applied through the mouthpiece 28 by the glassblower the isolated positive pressure on the disc valve 16 will not tend to open this valve while the suction or negative pressure in the tube 17 from the pump 17b will not tend to open the disc valve 18 from its seat 19 since the pressure in the casing would be less than the pressure in the upper valve casing 5 and would be greater than that in the lower tubular member 17.

When the glassblower blows in the mouthpiece to iniiate or expand the glass bubble 24 this tends to separate the diaphragms 9 and 10, and at the saime time forcing the lower disc 18 down tighter on its seat, raising the upper diaphragm 9 to move the valve disc 16 oit its seat. This allows the isolated gas pressure medium to enter the interior of the casing 1 and iiow through the conduits 21, 22 and 23 to expand the molten glass work 24 as desired. The amount of oral or breath pressure applied by the glassblower determines the degree of opening of the valve disc 16 and thus the rate of flow of the isolated inert gas to the work being blown. As soon as the pressure inside the casing 1, and also in the glasswork, reaches the pressure which the glassblower applies through his mouthpiece to the chamber 11, the diaphragm 9 will fall down again by gravity and close the inlet valve 5. If the glassblower wants to reduce the pressure inside the glasswork he releases some pressure from the chamber 11 through his mouthpiece. The greater pressure in the casing 1 will open the valve 18 temporarily until pressure in chatmber 11, casing 1 and work 24 is equalized then the valve 18 will drop closed by gravity.

Likewise when the glassblower applies suction to the mouthpiece 28 the reduced pressure in chamber 11 compared to pressure in the casing 1 draws the upper diaphragm 9 down to firmly close the valve disc 16 on its seat 15 and suck the lower diaphragm 10 upwardly as seen in FIG. 3 to raise the valve disc 18 olf its seat and the pressure medium in the casing 1 and the tubing 21, 22, 23 and in the glasswork 24 will be withdrawn to reduce the internal pressure when desired to contract the blown work 24. Varying the degree of suction by the glassblower varies the suction area between the valve 18 and its seat which varies the effective suction. When the negative pressure in chamber 11 and in the glasswork reaches the negative pressure the glassblower is applying to the chamber 11 through his mouthpiece, the diaphragm 10 will fall down by gravity and close the valve 18.

Since the entire dual valve structure is carried rigidly by the bottom or supporting plate 2 the removal of the casing or shell for adjustment exposes the entire internal working parts without disturbing their operative relations.

It is often desirable to keep a small ushing circulation of inert gas through the glass-'blown articles during the fabrication thereof, to prevent internal oxidizing by the atmosphere, especially when both of said positive and negative pressure control valves are closed. This is important where the conduit 17 is open to atmosphere (lower pressure) as well as being connected to a positive suction means such as 17b.

Referring to the drawings, a small inert gas bypass passage 3a is provided in the supporting plate 2 and extends in communication at one end with the positive inert gas pressure supply conduit 3, which as before mentioned, has a predetermined regulated low pressure of about 2 p.s.i. This bypass passage or conduit 3a extends into the supporting or base plate and turns upwardly to provide a needle valve controlled outlet port 3b opening into the interior of the casing, the port 3b being controlled by the needle valve 3c which has a knurled adjusting wheel or disc conveniently located below the bottom of the supporting plate. Adjustment of the thumb wheel of course axially adjusts the needle Valve to control the ow of the inert gaseous pressure medium through the port 3b, which ow must necessarily be very small. This bypass out-iiow from the port 3b through the conduit 21, to the molten glass articles being fabricated, prevents the atmosphere from entering the interior of the work and causing oxidizing, when for instance, a tubular glass conduit member is being heated and manipulated by the glassblower to fuse the same into the side of another glass member to provide a tubular bypass, or vent passage or the like. This bypass through the port 3b is necessarily very low, so as not to build up sutiicient undesirable pressure in the molten glass parts being fabricated or joined, to prevent them from expanding, swelling or blooming by internal gaseous pressure while the two diaphragm valves 16 and 18 are closed. This bypass pressure must be suiiiciently low to prevent pressure build up in the casing 1 sutiicient to open the valve 18 by lifting the diaphragm.

I claim:

1. A dual differential pressure control valve device for glass-blowing apparatus comprising a closed pressure-tight casing; a positive and relatively low pressure supply conduit, in communication with the interior of said casing, adapted to be connected to a molten glass-blowing device for applying positive or relatively low pressure from the interior of said casing to said molten glass-blowing device; positive pressure control valve means, fixed in said casing, having an outlet port opening into said casing controlled by said valve means; spaced relatively low pressure control valve means, xed in said casing, having a relatively low pressure port opening into said casing, controlled by said relatively low pressure control valve means; spaced positive and relatively low pressure actuated diaphragm means iixed in said casing between said positive and relatively low pressure control valve means; a common positive and relatively low pressure supply conduit means, connected to both of said positive and low pressure actuated diaphragm means, for simultaneously applying positive or relatively lower pressure than the pressure in said casing to both of said diaphragm means; said last mentioned conduit means extending out of said casing and adapted to be connected to a glassblowers oral positive or relatively low oral breath pressure applying means; an actuating connection, between said positive pressure diaphragm means and said positive pressure supply valve means, for opening said positive pressure supply valve means into communication with the interior of said casing; a second independent actuating connection, between said relatively low pressure control diaphragm means and said relatively low pressure control valve means, operable to selectively open said relatively low pressure control valve means in communication with said casing, when pressure in said relatively low pressure diaphragm means is reduced lower than the pressure in said casing to reduce the pressure in said casing, for reducing the pressure in said outlet conduit means to said molten glass-blowing device.

2. A dual differential pressure control device for molten glass-blowing apparatus comprising a pressure-tight casing; a positive or negative pressure delivery conduit, in communication with the interior of said casing, adapted to be connected to a molten glass-blowing conduit for supplying positive or negative pressure from the interior of said casing to said molten glass-blowing conduit; positive pressure control valve means, fixed in said casing, having a positive pressure outlet port opening into said casing controlled by said control valve means; spaced relatively negative pressure control valve means, fixed in said casing, having a negative pressure conduit extending out of said casing controlled by said negative pressure control valve means, and adapted to be connected to a negative pressure supply means; an annular dual diaphragm supporting ring, fixed in said casing, in spaced relation between said positive and negative pressure control valve means; spaced parallel fiexible diaphragm members, secured to and closing both sides of said supporting ring to form a closed isolated positive and negative pressure applying chamber therein; a glassblowers positive and negative suction pressure application conduit connected in communication with the interior of said charnber, between said diaphragms, and extending out of said casing, adapted to be connected to a glassblowers oral positive or suction pressure tubular conduit means for supplying isolated positive or negative `glassblowers oral breath pressure into said ring between said diaphragms; said diaphragms comprising a positive pressure actuated diaphragm adjacent said positive pressure supply valve means and a negative pressure actuated diaphragm adjacent said negative pressure control valve means; actuating means, connected between said positive pressure actuated diaphragm and said positive pressure control valve means, for opening said positive pressure control valve means by outward deflection of said positive pressure actuated diaphragm, by introduction of positive isolated oral pressure from the glassblower into said chamber; and an operating connection, between said negative pressure actuated diaphragm and said negative pressure control valve means, 'for opening said negative pressure control valve means by application of relative suction or negative oral pressure through said positive and negative pressure supply conduit by the glass lblower in said chamber to lower the pressure in said chamber below the pressure in said casing, for reducing the pressure in said casing and through said molten glass-blowing conduit to said work being blown.

3. A dual differential pressure control device for manually controlled glassblowing apparatus comprising a closed casing having a molten glass-blowing and fabricating outlet port; a dual diaphragm chamber, fixed in said casing, comprising an annular supporting ring and parallel spaced iiexible diaphragms closing both sides of the ring to form a closed isolated pressure and suction applying chamber; a positive and negative pressure supply conduit extending into said casing in communication with the interior of said chamber, adapted to be connected to a glassblowers oral breath pressure or suction tubular conduit supply exteriorly of said casing for applying the glassblowers positive pressure or negative suction pressure into said chamber on said diaphragms; a normally closed positive pressure control inlet valve in said casing adapted to control supply of positive pressure into said casing exteriorly of said chamber when said valve is opened; a positive actuating connection between said positive pressure inlet valve and one of said diaphragms for opening said positive pressure inlet valve by outward defiection of said one diaphragm when the glassblowers positive breath pressure introduced in said chamber exceeds to a predetermined extent the pressure in said casing exteriorly of said chamber, for increasing the pressure in said casing delivered through the said chamber outlet port; a suction pressure outlet port in said casing adapted to be connected to suction applying means exteriorly of said casing; a suction pressure control valve in said casing normally closing said suction pressure outlet port; connecting means from said suction pressure control valve connected to the other diaphragm to open said suction outlet port by inward deflection of said other diaphragm toward said chamber when suction applied within said chamber by the glassblower is reduced to less than the internal pressure in said casing exteriorly of said chamber, to reduce the pressure in said casing and through said molten glassblowing and fabricating outlet port to the glasswork being fabricated.

4. A dual differential positive and negative pressure control device for oral glass-blowing apparatus comprising a supporting plate and cover therefor forming a closed positive or negative pressure enclosing casing; a tubular positive and negative pressure supply conduit, lixed in said plate, leading outwardly from the interior of Said casing, adapted to be connected to a molten glass-blowing and manipulating tube for blowing and fabricating molten glass articles; a suction applying conduit fixed in said supporting plate for communication with the interior of said casing, adapted to be connected exteriorly of said casing to a source of suction pressure; a suction pressure control valve in said Casing normally closing said suction conduit; a positive pressure Supply conduit fixed in said plate for supplying a positive pressure into said casing, adapted to be connected exteriorly of said casing to a source of predetermined positive pressure; normally closed positive pressure control valve means in said casing normally closing said positive pressure supply conduit fixedly supported by said positive pressure supply conduit in spaced opposed aligned relation to said suction pressure control valve; a glassblowers positive oral pressure and suction applying conduit fixed in said plate and extending into said casing in closed fixed supporting relation to said positive pressure control valve means, and extending out of said casing, adapted to be connected to a glassblowers oral pressure and suction supply conduit for selectively applying positive oral pressure or suction to said positive pressure and suction applying conduit; a cylindrical dual diaphragm supporting ring tixedly supported in said casing by said last mentioned conduit, between said positive pressure control valve means and said suction control valve; spaced first and second parallel flexible diaphragms sealed to the opposite sides of said ring to form an isolated positive and suction pressure chamber therebetween; a communicating passage connected between the interior of said chamber and the glassblowers oral pressure and suction applying conduit means for increasing the pressure in said chamber above the pressure in said casing to ex said first one of said diaphragms outward relative t said chamber, or reduce the pressure in said chamber relative to pressure in casing to flex said second one of said diaphragms inward toward the chamber; a positive operating connection, between said first diaphragm and said positive pressure inlet control valve, tor opening said inlet control valve proportionally to the degree of outward deliection of that diaphragm; a positive actuating connection, between said second diaphragm and said suction inlet valve, for opening said suction inlet valve in proportion to inward deflection of the second diaphragm.

5. A device as set forth in claim 4, including7 a restricted positive pressure bypass conduit, connected between said positive pressure supply conduit and the interior of said Casing, for supplying positive pressure into said casing while the aforesaid positive pressure and suction control valves are closed; including pressure flow regulating means in said `bypass passage for regulating the flow of positive pressure from said positive pressure supply conduit into said casing.

y6. A dual differential pressure control device for molten glass-blowing apparatus comprising a closed casing having a bottom closure plate; a positive pressure supply conduit, ixed in said plate and extending upwardly, having a central positive pressure outlet opening facing downwardly into said casing, and adapted to be connected to positive predetermining pressure supply means exterior of said casing; a relative negative pressure conduit in said plate opening upwardly in said casing in vertically spaced aligned relation below said positive pressure supply opening, and opening outwardly at its lower end away from the casing; a relatively negative pressure control valve in said casing, in aligned spaced relation below said positive pressure supply conduit outlet; a closed dual diaphragm chamber, -ixedly supported in said casing, comprising a cylindrical supporting ring intermediate said positive pressure and relatively negative pressure control valves; a glass blowers positive and relatively negative oral pressure supply conduit fixed in said plate in supporting open communication with said chamber; said glassblowers oral positive pressure and negative pressure supply conduit extending through said plate outwardly away from said casing and adapted to be connected to a glass-blowers mouthpiece; a positive pressure responsive iirst diaphragm closing the upper side of said chamber, deliectable upwardly by application of glassblowers positive oral pressure introduced into said chamber; a relatively negative pressure responsive second diaphragm comprising a lower wall of said chamber, facing downwardly toward said relatively negative pressure control valve, detiectable upwardly and inwardly of said chamber by application of relative negative glassblowers breath pressure in said chamber; a positive operating connection, between said positive pressure responsive first diaphragm and said positive pressure control valve, for Opening said last mentioned valve by upward deflection of said last mentioned diaphragm; a positive operating connection between said relatively negative pressure responsive second diaphragm and said relatively negative pressure responsive control valve, for opening said last mentioned valve by upward deflection of the last mentioned diaphragm incident to application of the glassblowers oral negative pressure in said chamber which pressure in said chamber is reduced lower than the pressure in said casing.

7. A device as set forth in claim 6, in which said positive pressure supply conduit and said glass'blowers positive and relatively negative pressure supply conduit extend upwardly in spaced parallel fixed relation from said bottom closure plate at opposite sides of the edge of said chamber, and curve inwardly adjacent the top of said casing toward each other with the upper ends thereof ixedly supporting said positive pressure control valve; and a positive supporting connection between the opposite sides of the dual diaphragm chamber and each of the last mentioned conduits.

8. A device as set forth in claim 7, including a regulatable restricted bypass conduit, between said positive pres sure supply conduit and the interior of said casing, for feeding and regulating a limited pressure iluid bleed from said positive pressure supply conduit into said casing, to maintain a predetermined low positive pressure fluid ow out of said casing through the molten glassblowing and fabricating tube when both of said positive and relatively negative pressure control valves are closed by lack of glassblowers positive or relatively negative pressure in said chamber between said diaphragms.

References Cited UNITED STATES PATENTS 2,286,282 6/1942 Joesting 137-5961 XR 2,825,361 3/1958 Selvos 137-596.18 2,966,927 1/1961 Peters 137-596.18 3,052,064 9/1962 Kaeser 65-300 3,181,563 5/1965 Gitfen 65-301 XR WALTER A. SCHEEL, Primary Examiner.

R. I. SMITH, Assistant Examiner.

U.S. Cl. X.R.

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