US2402234A

US2402234A - Method of and apparatus for forming glassware

Info

Publication number: US2402234A
Application number: US413624A
Authority: US
Inventors: Walter K Berthold
Original assignee: Hartford Empire Co
Current assignee: Hartford Empire Co
Priority date: 1941-10-04
Filing date: 1941-10-04
Publication date: 1946-06-18
Anticipated expiration: 1963-06-18
Also published as: GB560576A

Description

June 18, 1946.- w BERTHQLD 2,402,234

METHOD OF AND APPARATUS FOR FORMING GLASSWARE Filed Oct. 4, 1941 3 Sheets-Sheet 1 m liwlhmllg Jizvefitnr waft BPKBBI'ZbU fllill my? 5 E wsK grim-i .233 i I as June 18, 1946. w BERTHOLD 2,402,234 METHOD OF AND APPARATUS FOR FORMING GLAssWARE 3 Sheets-:Sheet 2 Filed Oct. 4, 1941 WEE 51 K BBPZIJDZLI 6. m n a W. n 2 w 2 w// 1 1. .II 5 fl 5: "m

flZZIarnEys June'18,'1946. W. K. BERTHOLD 4 2,402,234

METHOD OF AND APPARATUS FOR FORMING GLASSWARE Filed Oct. 4, 1941 s Sheets-Sheet s Even Z; 121* AZQZZIEPKBEPZLIJQIH. I

- flZZ K171225975 Patented June 18, 1946 METHOD OF AND APPARATUS FOR FORMING GLASSWARE Walter K. Berthold, Itockville, Conn., assignor to Hartford-Empire Company, Hartford, Coma, a

corporation of Delaware Application October 4, 1941, Serial No. 413,624

9 Claims.

This invention relates to the manufacture of charges of molten glass into articles of glassware,

such as bottles, Jars and other containers and particularly those which have neck finish or finished rim portions at their open ends or mouths.

An extensively used prior art method of forming glass charges into containers is known as the blow-and-blow process. It is sometimes termed the narrow-neck" process since most bottles and other containers having relatively narrow neck portions are made by its use.

In the blow-and-blow or narrow-neck process, a charge of molten glass usually is delivered downwardly into the temporarily open upper'end of an inverted parison mold. Such a mold may comprise cooperative parison body and neck molds. A neck pin may project from below vertically into the neck mold at the time of the delivery of the charge to the parison mold or be raised to such an upwardly projected position concurrently with or shortly after such delivery. This neck pin terminates below, or not substantially above, the level of the juncture of the inverted neck and parison body molds. The neck pin cooperates with the usual thimble or neck pin guide and with the neck mold to define an annular narrow space at the lower end of the inverted parison mold into which glass of the charge is compacted by settle blowing pressure fluid (air) applied to the upper surface of the glass charge in the parison mold, whereby to form the neck finish or finished rim portion of the article being made.

The neck pin is then retracted downwardly and, after a suitable period of time to allow any desirable or necessary "corkage reheat, counterblowing air under pressure is admitted to the space in the neck finish or finished rim portion of the article that has been left vacant by the downward retraction of the plunger. This will enlarge the neck pin hole upwardly into the body portion of the glass in the body mold and will counterblow such glass against the wall of the cavity of the inverted parison body mold and against a balile or bottom plate which has been placed in position to close the previously open upper end of the inverted parison body mold.

The hollow parison produced by the steps above described may be transferred to a cooperative blow mold and blown in the latter to produce a bottle or other glass article of the final shape desired.

The present invention provides improvements over the blow-andblow or narrow-neck process substantially as just described, particularly in or eliminates the settle blow waves in the side walls of the finally blown article which are inherent I in the blow-and-blow process. The method of the present invention also distributes the glass of the charge more uniformly throughout the walls of the article during the formation thereof than is doneby the usual blow-and-blow process, and is less adversely affected in the production of a series of similar articles by variations of the weight of diiferent generally similar charges from which such articles are to be formed. Other advantages over the prior art methods are obtained as hereinafter will be pointed out or will become apparent to those skilled in the art.

As in the previously practiced blow-and-blow process, a charge of glass may be delivered downwardly through the temporarily open upper end of the inverted parison mold into the forming cavity of such mold as an early step in performing the method of the present invention. Such method then departs from the practice of the blow-and-blow process. According to the present invention, the descent of the charge is checked in the inverted parlson mold by the tip of a vertically movable pressing plunger which projects through the neck mold to a sufficiently high level in the body mold to support the charge as an entity completely above the internally grooved or otherwise 'intemally configured neck finish forming wall of the neck mold. The contact of the tip of the pressing plunger with the charge is initially with the central portion only of the original lower end surface of the charge and subsequently with glass at the interior of the charge as relative vertical movements occur between the plunger tip and the glass surrounding such tip.

Upward-movement of the plunger tends to raise the charge as an entity in the inverted parison glass mold without, however, preventing downward movement of glass of the charge on the plunger tip. Air under. pressure is applied'to the top surface of the charge, tending to compact it downwardly in the inverted parison mold. These opposing forces act on the glass charge as the plunger is raised in the inverted parison mold from its initial charge contacting position to the end of its upward stroke, quickly to form the glassy of such charge into a hollow parison having a neck flnishor finished rim portion and a hollow body. The cavity of this hollow body extends through such neck finish or finished rim portion longitudinally of the parison body for a substanbe effected, after tial part, preferably one-half or more, of the total length of the parison. The wall of this internal cavity will have been marvered by the contact of the pressing plunger therewith in opposition to the downwardly directed air pressure on the upper surface of the glass. The length of the plunger insertable into the inverted parison press mold and of its pressing stroke are predetermined to assure the desired length of internal cavity in the body of the glass parison and also to assure the provision in the parison mold of a hollow parison extending substantially the full length of the glass forming cavity of such mold. At the completion of the upward stroke of the pressing plunger, the level of the upper surface of the glass in the parison mold preferably is at or close to that of the upper end of the cavity of the body mold. Counterblowing may thereafter downward retraction of the pressing plunger and the application of a suitable bottom plate or bafiie to the upper end of the parison mold, without causing the aforesaid undesirable settle blow waves in the side walls of the final article.

The hollow parison thus produced may be subjected to suitable further steps or treatment to form it into a finally blown article of the final shape desired.

Reference now may be had to the accompanying drawings, in which Figure 1 is a more or less diagrammatical view. mainly in vertical section, showing an inverted parison mold and .certain associated parts at a charge receiving station just at or immediately after descent of a charge in theparison mold has been checked therein by the tip of a pressing plunger which is then located at its initial glass charge contacting position in the parison mold:

Fig. 2 is a'view similar to Fig. 1 after a settle blow head has been operatively applied to the funnel at the top of the inverted parison mold body and after the pressing plunger has completed part of its upward stroke;

asoaaae of into a narrow-necked article as shown in Fig.

; and

Fig. 18 is a fragmentary vertical sectional view of a novel apparatus for guiding, positioning and operating a pressing plunger in the performance I of the method of the present invention.

Fig. 3 is a view similar to Fig. 2 at the instant the pressing plunger reaches the end of its upward stroke;

Fig. 4 is a view similar to Fig. 3 except that the settle blow head has been removed and is not shown;

Fig. 5 is a view similar to Fig. 4 except that the funnel has been removed and the pressing plunger has been retracted downwardly past its initial glass charge contact position to a lower neck mold clearance position:

Fig. 6 is a view similar to Fig. 5 except that a bottom plate or baffle has been applied to the upper end of the parison mold and the cavity in the glass left by the withdrawal of the plunger is being enlarged somewhat by counterblowing;

Fig. 7 shows the counterblown parison after removal of the bafiie;

Fig. 8 shows the parison supported at its neck finish portion after removal of the body mold. the view also showing puff or other blowing of the parison;

Fig. 9 shows the parison after it has been reverted and transferred to a final blow mold;

Fig. 10 shows the blowing of the parison to final form in the final blow mold. a final blow head having been operatively applied to the latter:

Figs. 11, 12, 13, l4, l5. l6 and 17 are views which correspond generally with Figs. 1, 2, 5, 6, 8, 9 and 10, respectively, but illustrate a typical use of the invention to form a mold. charge into a wide-mouthed article, specifically a jar, instead A typical procedure by which a charge of molten glass may be formed into a narrow necked article, specifically a bottle as shown in Fig. 10, may comprise the fOllOWin-g steps.

A charge of molten glass produced by a feeder (not shown) or in any other known manner, may be dropped or otherwise delivered end-wise through a funnel guide I, Fig. 1, into the cavity 2 of the inverted body mold 3 of an inverted parison mold assembly at a suitable charge receiving and parison forming station. The inverted parison mold assembly includes a neck mold 4 and a thimble or plunger guide ring 5 carried by the neck mold. The body mold and the neck mold each may be of the usual twopart construction. A pressing plunger 6, which preferably tapers toward its tip for part of its length, projects through the thimble and the neck mold into the cavity of the inverted body mold to a height in the latter sufiicient to cause the charge, indicated at i in Fig. l, to be supported on the tip of the plunger it completely above the internally grooved or otherwise configured molding wall of the cavity 6 of the neck mold.

It is unnecessary to illustrate or describe herein the constructions and functions of the parts of the parison mold assembly shown more or less diagrammatically in Fig. 1 or of suitable means for supporting and operating them as these matters are well known to those skilled in the art. Reference may be had to Patent No. 1,911,119. granted May '23, 1933, to H. W. Ingle for a disclosure of particular means suitable for supporting and operating these cooperative mold parts and adjuncts if it is desired to make use of such means.

The thimble shown in Fig. 1 includes a novel structural feature which adapts it for cooperation with the novel plunger guiding and positioning mechanism shown in Fig. 18 and to be hereinafter described. Since, so far as performance of the method of the invention is concerned, any suitable thimble or plunger guide ring may be employed, the thimble shown in Fig. 1 will not be further described at this point, but the novel feature thereof will be pointed out in connection with the description of the mechanism of Fig. 18.

The plunger t5, as aforesaid, is of the pressing plunger type instead of being merely a neck pin as disclosed in the Ingle Patent 1,911,119, for ex ample. It is of sufiicient length to project through the neck mold a substantial distance vertically in the cavity of the inverted body mold, preferably to about half the length thereof. So far as performance of the method of the present invention is concerned, the plunger 6 may be moved vertically at the proper times in the directions and to the extents required by any suitable operating mechanism and, at least in theory. by hand or manually operated instrumentalities. In practice, I prefer to use the operating mechanism shown in Fig, 18, hereinafter to be described. Other suitable forms of operating mechanism are disclosed in the copending application of George E. Rowe, Serial No. 410,747, filed September 13, 1941, for Apparatus for and methods of forming glassware, which is of common ownership with the present application.

After the stageof operation shown in Fig. 1 has been reached and before glass of the charge suracoaaae rounding the tip of the plunger has had time to Pref this regard. If so, it preferably is such'that the upward movement of the plunger in contact with the glass charge will be commenced first.

At the stage of operations 'shown in Fig. 2, the plunger has completed part of its upward stroke to press glass of the charge against the cushion of compressed air above such charge. The pressure of such air cushion and gravity have caused glass surrounding the plunger to move downwardly thereon into the upper part of the cavity of the neck mold. as indicated at 10.

Fig. 3 shows the conditions at about the instant of completion of the upward pressing stroke of the plunger and while air under pressure is still being applied to the upper surface of the glass charge. The conjoint effect of these oppositely acting forces is to compact glass of the charge surroundapproximately half the length of the glass in the.

mold. The wall of this cavity will be marvered and chilled somewhat by the contact of the plunger with the glass of the charge as such cavity is being formed. The plunger may be cooled internally during its contact with the glass. as in the manner disclosed in the aforesaid Rowe application, Serial No. 410,747. The operations just described are performed very quickly. Since the results thereof cannot be observed while they are being produced, it is not known whether the neck finish portion of the article is formed exactly at, slightly before or. slightly after the instant of completion of the upward pressing stroke cfthe plunger.

The settle blow head 9 is a combination parison bottom bame and blow head adapted to cooperate with the funnel I for the performance of its blowing function as shown in Figs. 2 and 3, and directly with the upper end of the inverted body mold to serve as a bottom baffle as shown in Fig. 6. Such a combination baffle and blow head, and suitable means for operating it, are well known in the art. examples thereof being disclosed in the aforesaid Ingle Patent No. 1,911,119.

Fig. 4 shows a stage ofoperations at which the combination ballle and blow head 9 has been removed but the funnel is still in place and the pressing plunger is still raised. This is followed by removal of the funnel and downward retraction of the plunger past the glass charge initial contact position to a lower mold clearance position such, for example. as that shown in Fig. 5. Thereafter, the member 9 is applied to the mold body 3 to serve as a balfle and counterblowing air is applied to the space vacated by the plunger, as indicated by the arrows H in Fig. 6, to enlarge the cavity it in an upward direction and to force 1 Wise.

. 6 glass ofthe charge against the bame member 9. The latter has a shallow concavity 9a in its bottom surface. supplementing the body mold cavityand providing a space of limited size into which glass can be forced to permit enlargement of the axial cavity in the glass. A countcrblown hollow parison. designated 15 in Fig. 6, is thus produced.

The member .9 may then be removed and the inverted hollow parison 15 may be permitted to reheat at its bottom end then uppermost) and at its interior while its external side walls are in contact with the closed heat extracting mold walls, substantially as shown in Fig. 7. Fig. 8

shows puff blowing of the inverted parison after the body mold has been removed therefrom to leave such parison supported only at its neck finish portion by the neck mold. The steps shown in Figs. 7 and 8, or either of them, may be omitted or employed as is'deemed desirable or required in forming any particular article in accordance with the present invention.

Fig. 9 shows the parison in reverted position in a blow mold ll after such parison has been transferred from the parison forming station of the preceding views. This transfer and the reversion of the parison may be effected by a swinging movement of the neck mold, carrying the parison, as disclosed in the aforesaid Ingle Patent 1,911,119. The low position of the plunger, Figs. 5 to 8, inclusive, permits such a movement of the neck mold and thimble unit.

Fig. 10 shows conditions after the parison has been blown by air from a flnal'blow head 11 to form an article of glassware, in this case a bottle ID, of the final shape-desired.

Operations similar to those described may be employed to form a charge of molten glass into other glass containers. either narrow-necked.

wide-mouthed or semi-wide-mouthed ware. Certain stages in the manufacture of a jar by the method of the present invention are shown in Figs. 11 to 1'7, inclusive. In these operations. a suitable inverted parison body mold 2|, a suitable neck mold 22. carrying a suitable thimble 23. and a suitable plunger 24 may be used. at times in conjunction with the funnel land/or the combined settle blow head and baflle 9 ubstantially as hereinbefore described. A glass charge 25 is shown in Fig. 11 in the cavity of the inverted body mold as it is supported therein by the tip of the 'plunger 24. Such charge may be formed by the conjoint plunger action and opposing compressed air cushion to have'an internal cavity 26 extending for the greater part of the length thereof and a neck finish portion 21 at the lower end of the cavity, as shown in Fig.

12 and also in Fig. 13. Counterblowing. Fig. 14.

to time. will not alter the upward strokes of the plunger either as to the length thereof or other- Another advantage of the present invention is that such weight variations do not alfect filling of the annular space, which may be quite narrow. around the plunger-in the neck mold with glass of the successive charges to form the neck finish portions of the hollow parisons formed of such charges. These features of the invention. are particularly important and bene- The invention provide for desirable distribution of the glass of a charge throughout the walls of the article being made, so that such article may be formed with its side walls of substantially uniform thickness at all portions thereof. The improvement in this regard is particularly marked in the case of articles having neck portions of relatively small diameters. Also, aspreviously pointed out herein, the invention provides an effective, advantageously usable way of eliminating settle blow waves in the side walls of a bottle or other blown hollow glass article.

While, as aforesaid, the plungers used in performing the method of the'present invention may be operated by various other means, I prefer to use novel mechanism which the invention provides for this purpose. Such a mechanism, as shown in Fig. 18, comprises a vertically disposed pneumatic cylinder II in which a piston 32 is vertically reciprocable. The piston carries an upwardly projecting rod 33 which extends slidably through a bearing unit 34 at the central portion of the upper head 35 on the cylinder 3| into an open-topped cylindrical holder 38 on the cylinder 3|. The rod 33 carries the plunger that is to be used in a particular installation for the performance of the method. As shown in Fig. 18, the rod carries the plunger I, hereinbefore referred to, the butt end portion 8a of such plunger being detachably secured to the rod in any suitable known way, as by a screw threaded connection (not shown).

The holder 36 houses a plunger guiding and positioning mechanism comprising a cylindrical casing 31 fitting within the holder and secured, as at 33, against turning about its vertical axis relative to the holder. The upper end portion 31a of the casing 31 protrudes from the holder 38, is reduced in size internally at 39, and is formed at its upper surface to provide a flat horizontal seat 40 on which may rest the flat-bottomed base 4| of an annular lower section 42 of the aforesaid thimble or plunger guide rings! of the Fig. 1 form of neck mold assembly. The

superposed portions of the upper end portion 31a of the casing 31 and of the lower section 42 of the thimble 5 have outwardly projecting oppositely beveled edge portions adapted to be engaged by bevel-sided grooves 43 in the confronting faces of aligning and locking members 44 so that the latter, on closing, will bias the parts 4i i and 31a to axially aligned relation to each other if any relative lateral movement between them is required and then will lock such parts together in their aligned relation.

The lower portion of the casing 31 contains a retainer 45 for a coil spring assembly 46 which surrounds the rod 33 and exerts an upward thrust on the flanged lower end 41 of a vertically movable cylindrical plunger guide 48. The guide 48 i vertically reciprocable in a reducing bushing 49 which is mounted within a portion of the casing 31 and is suitably formed to maintain the cylindrical guide 48 concentric with the upper portion 31a of the casing 31. Theguicle 48 therefore will be axially aligned with the thimble i and hence with the closed neck ring 4 when the thimble section 42 and the upper end portion 37a of the casing 31 have been aligned and locked together as hereinbefore described. The butt portion 8a of the plunger 6 may be formed with one or more peripherally enlarged cylindrical bearing portions 50 fitting closely but slidably in the plunger guide 48 so that the plunger will be centered in relation to the neck mold when the guide 48 is aligned with such mold.

The plunger guide is provided with an upwardly facing internal shoulder 5| adjacent to its lower end. A cylindrical spacer ring 52 of a predetermined height flts within the lower portion of the plunger guide so that the upper edge of such spacer ring lie in the path of the bottom surface of the lowermost peripherally enlarged bearing .portion 50 of the plunger when the latter has been retracted downwardly by the piston 32 for part of the downward stroke of the latter from the position shown in Fig. 18.

The operation of the parts of the plunger guiding, positioning and operating pparatus as described so far is substantially as follows. The plunger 6 is shown in full lines in its uppermost position in the cavity 2 of the inverted parison body mold 3, this position having been reached by reason of upward movement of the piston 82 in the pneumatic cylinder 3| until the upper end of the butt portion of the plunger struck the downwardly facing shoulder 83 which is located at the top of the downwardly flaring open bottomed main cavity 54 in the thimble 5 and at the lower end of the central plunger guiding opening 55 in such thimble. Application of air under pressure to the space above the piston 82 in the cylinder 31 and relief 01' pressure below such piston will cause a downward stroke of the piston and attendant downward movement of the plunger 6. Such movement of plunger will be relative to the plunger guide 48 until the plunger butt portion 50 strikes the spacer 52, after which the remainder of the downward stroke of the piston 82 will cause the plunger and the guid 83 to move downward together against the resistance of the compressed spring assembly 46 until the upper edge of the guide 48 has reached the position indicated by the dot-and-dash lines at 56 and the plunger tip is at the p sition indicated by the dot-and-dash lines at 51. This is the lowermost, neck mold clearance position of the plunger. On sufllcient relief of pressure above the piston 32, the spring assembly 46. will be effective to return the plunger guide to its full line position at which the flanged lower end portion thereof will strike the fixed reducing bushing 49 and at the same time to move the plunger upwardly until its tip is at the initial glass charge contact or loading position indicated by the dotand-dash lines at 58. Further upward movement of the plunger 6, from position 58 to the full line position, will be independent of the plunger guide and may be efiectedby an upward stroke of the piston 32 in the cylinder 3i, as aforesaid.

The plunger operating structure Just described is substantially as disclosed in the aforesaid application of George E. Rowe, Serial No. 410,747, filed September 13, 1941, as the invention of said Rowe and such structure, per se, is not claimed herein. The improvement features provided by the present invention in connection with such operating structure will now be particularly described. These features are mainly concerned with prevention of leakage of air or other pressure fluid from the communicating supp y passages of the plunger guiding, positioning and operating be substantially as disclosed in the logic Patent- No. 1,911,119. The passage 60 may be closed at its lower end and in open communication at its 'upper end with the lower end of a vertical air passage ii in a wall of the cylindrical holder 3!. The passage ll may be closed at its top and provided adiacent to its top with a port 8! which opens through the inner wall of the upper portion of the holder 36 in communication with a transverse port or short passage 83 which is provided in the upper portion of the casing 31 to extend irom the outer to the inner surface of such casing. The port 62 may be extended around the inner periphery of the holder 36 in the form of a chamber 62a.

. The passage 83 communicates at its inner end with a channel 84 in the outer periphery of the lower portion of an annular piston 65 which fits slldably in the upper end portion of the casing 31. Vertical passages, as at 68, lead from the. lower side of the channel 64 to an annular chamber 81 which is provided within the upper part of the casing 31 around an externally reduced upper portion a of the bushing 49. The lower DOT-e tion or the piston 65 is located in the annular chamber 01 in spaced relation with the reduced portion a of the bushing 49. The piston 65' carries an upwardly proiectinginwardly'stepped sealing ring 88, located directly-above the part a but spaced from the upper edge of the latter to provide an annular port I for the chamber 61 at the upper inner side of the latter. This port 6! is closed except for its communication with the chamber 61 when the movable plunger guide ll is at the upper end of its stroke as shown in full lines in Fig. 18, this by reason of the close sliding fit between the guide 48 and the sealing ring ll. However, when the guide it has been retracted downwardly until its upper edge is at the position indicated by the dot-and-dash lines J56, air under pressure from the chamber 61 may pass through the port 89 upwardly past the upper end portion of the guide 48, which may be reduced externally at a to provide spacefor such passage, to the interior of the thimble 5. Thence, when the plunger is down, such air may pass through the interior the neck mold to the interior of the partially formed glass parison proiecting upwardly from the neck mold to-counterblow the parison or for puff or other blowing of such parison.

The air entering the annular channel 64 in the piston will exert upward pressure on the latter to maintain the beveled upper edge portion 68a oi the sealing ring in air-tight contact. with the inclined inner peripheral wall of a cooperative sealing ring 10 which constitutes an element of the assembly of thimble components. The ring II is retained in a'suitably sized and configured annular groove or way H between the bottom of the upper section of the thimble and the lower thimble section 42 at the Joint between these sections so as to be capable of a slight floating movement. The arrangement is such as to assure that the contacting rings 68 and II will seal the Joint between the sections 01 the thimble between separate parts of 10 against the escape of air through such joint when the piston 65 is being urged upwardly by air pressure in the annular space 64,

Rings 12 may be provided on the piston 65 to prevent leakage of air between it and the portion of the cylindrical casing 31 above the passages 3-64. A sealing ring 13 may be provided in a suitable groove between the contiguous surfaces 0! the upper end portions of the holder 38 and casing 31 above the passages 6263 for a like purpose. A vent 14 to the atmosphere may be 1 provided to prevent building up or pressure in the annular space 15 above the piston 65. A radial slot 16 may be provided in the thimble supporting surface at the top of the casing 31 to permit the escape of air from the space 'I'I between the sealing ring and the portion oi the thimble section 42 below the level of the sealing ring 10.

The thimble 23 01 the neck mold and thimble assembly or the Fig. 11 form of structure is shown as consisting of parts generally like those hereinbeiore described as components of the thimble 5 of Figs. 1 and 18. Thev neck mold and thimble assembly 01' the Fig. 11 form of structure therefore may be used with'a plunger guiding, positioning and operating mechanism substantially like that shown in Fi 18.

The invention is not limited to the exact details, either oi structure or method, which hereinbetore have been pointed out, as changes therein will readily occur to those skilled in the art.

I claim:

1. The method of forming a charge of molten glass into a hollow parison which comprises dropping the charge into the cavity of an inverted parison mold, checking downward movement of the charge as a whole at a predetermined level within said inverted parison mold so that the upper and lower ends oi the charge are spaced ,tmporarily from the levels of the upper and lower ends or the cavity 01'- said inverted parison mold. thrusting a vertically movable upright pressing plunger upwardly in the cavity of the inverted parison mold to impart a -liiting force to the glass of the charge by contact of the upper end of the upwardly moving plunger initially with the central portion only of the original lower end surface of the charge in the inverted parison mold and subsequently with glass of thecharge at the interior'thereot, and applying flu'idunder pressure to the upper surface of the charge in the inverted parison mold to oppose the action oithe upwardlymoving plunger on the glass of the charge, whereby to cause part of the glass of the charge to move downwardly to fill the space within the lower end portion of the cavity of said inverted parison mold around the plunger therein and other glass of the charge to be dis- .placed upwardly to produce an axial cavity extendingnpwardly in the glass in the mold from its lower end for a substantial part of the length thereof and to raise for a substantial distance the level of the upper surface oi the glass in the inverted parison mold, a

2. The method of forming a'hollow parison which comprises dropping 'a charge of molten glass onto the tip of an upwardly movable upright pressing plunger that projects upwardly in the cavity oi! an inverted parison mold in spaced relation with the side wall of said cavity and is eilective to check the 'iall'oi said charge in the cavity at a predetermined distance above the lower end of said cavity, raising the plunger in the cavity of said mold toimpart a lifting force to the acoaaaa charge at the axis of said charge, and, during said raising of the plunger, applying a fluid under pressure to the upper surface of the charge in the mold to oppose said lifting force on the glass at the axis of the charge and to accelerate downward movement of glass oi the charge in the space between said plunger and the side wall of the cavity of said inverted parison mold.

3. The method of forming a hollow pn which comprises delivering a charge of molten glass axially downward into an open ended ver-- tical molding cavity having a height substantially greater than the length of said charge, checking. downward movement of said charge in said cavity so that the upper and lower ends of the charge will be temporarily located at levels respectively below and above those of the corresponding ends of said cavity, and substantially simultaneously applying a motive force directed upwardly from below against the vertical central portion only of the charge and a yieldalole motive force directed downwardly from above against the entire upper surface of said charge to form said charge into a parison having an overall length substantially co-extensive with that oi said molding cavity and having an internal cavity open at the lower end of the parison and extending vertically in said parison from its lower end for a substantial part of the overall length thereof.

4. Th method of forming a hollow parison which comprises dropping a charge of molten glass into the cavity of an inverted parison mold having a neck finish forming part at its lower end, checking descent of the charge in said cavity before the lower end of the charge hasdescended into said neclr finish forming part of said inverted parison mold, thrusting a pressing plunger from below axially upward in the cavity of said inverted parison mold against and into the vertical central portion of the charge for a substantial part of the complete height of said charge, and applying air under pressure to the entire upper surface of said charge during the upward thrust of said pressing plunger to oppose upward dis placement of glass of the charge by the upward thrust of the plunger and to aid downward movemerit of glass of the charge surrounding said plunger into the necl; finish forming part of said inverted pariscn mold.

5. The method of forming a hollow parison which comprises dropping a charge of molten lass into the cavity oi an inverted parison mold l2 into said neck finish forming part of said invcrwd parison mold, thrusting a pressing plunger from below axially upward in the cavity of said inhaving a neck finish forming part at its lower end, checking descent of the charge in said cavity before the lower end of the charge has descended into said neck finish forming part of said inverted parison mold, thrusting a pressing plunger from below axially upward in the cavity or said inverted parison mold against and into the vertical central portion of the charge for at least half the height of the cavity of said inverted pax'ison mold, and applying air under pressure to the entire up= per surface of said charge during the upward thrust of said pressing plunger to oppose upward displacement of glass or" the charge by the upward thrust of the plunger and to aid downward movement of glass of the charge surrounding said plunger into the neclr finish forming part of said inverted parison mold.

6. The method of forming a hollow parison which comprises dropping a charge of molten glass into the cavity of an, inverted parison mold having a neck finish forming part at its lower end, checking descent. of the charge in said cavity before the lower end of the charge has descended verted parison mold against and into the vertical central portion of the'charge fora substantial part of the-complete height of said charge, applying air under pressure to the entire upper surface of said charge during the upward thrust of said pressing plunger to'oppose upward displacement of glass of the charge by the upward thrust of the plunger and to aid downward movement of glass of the charge surrounding said plunger into-the neck finish formin part of said inverted parison mold, withdrawing said plunger downwardl out of contact with the glass in the cavity of said inverted perlson mold, applying a parlson bottom bade to the upper end of said cavity, and applying air under pressure from below into the space within the glass left by the withdrawal of said plunger to produce a counterblown parison Within said inverted parison mold.

7. The method of forming an article of hollow glassware having a neck finish portion at the open end thereofwhichcomprlses dropping a charge of molten glass into a vertical molding cavity having a neck finish forming portion at its lower end and having an overall height substantially greater than the length of the charge, checking downward movement of the charge in said cavity before any glass of said charge has descended into the neck finish forming portion of the molding cavity but after the upper end of the charge has reached a level substantially below that of the upper end of said molding cavity, then forming said charge into a parison having an overall length substantially equal to the height of the molding cavity by thrusting a pressing plunger upwardly from below in contact with glass or" the vertical central portion only of the charge to displace glass of the charge upwardly to the upper end of said molding cavity and simultaneously subjecting the entire upper surface of the charge to pneumatic pressureto oppose upward displacement oi glass by the plunger and to aid movement of glass of the charge downwardly in the space surrounding the plunger into said necl: finish forming portion of the molding cavity, withdrawing said plunger downwardly out of contact with the hollow parison in said molding cavity, applying a parison bottom bailie to the upper end of said molding cavity, counterblowmg the hollow parison in said molding cavity, transterring the counterblown parison to a final blow mold, and blowing said counterblown parison to final form in said final blow mold.

8. In glassware forming apparatus, the coinbination with a parison forming unit comprising an inverted parison body mold and an inverted necis mold and thimble or plunger guide ring assembly at the lower end of the body mold, oi a pressing plunger, means for supportin the press ing plunger in vertical position and for reciprocating it in a vertical path extending from a lower level through said neck mold and thimbie or plunger guide ring assembly into said body mold in substantially axial alignment therewith, for guiding the plunger in its vertical reciprocations, said last named means including an opentopped substantially cylindrical casing surrounding said plunger in concentric relation therewith and in contact at its upper end with said neck mold and thimble or plunger ring assembly, means for supplying air under pressure to the interior of said cylindrical casing and thence to the interior of said neck: mold and thimble or plunger guide ring assembly when the plunger is at the lower end of its path of vertical movements, and means for sealing the place of contact of the upper end of said cylindrical casing with said neck mold and thimble 0r plunger guide ring assembly to prevent leakage of any of said air under pressure to the outside of said casing at said place of contact.

9. In glassware forming apparatus, the combination with a parison forming unit comprising an inverted parison body mold and an inverted neck mold and thimble or plunger guide ring assembly at the lower end of the body mold, of a pressing plunger, means for supporting the pressing plunger in vertical position and for reciprocating it in a vertical path extending from a lower level through said neck mold and thimble or plunger guide ring assembly into said body mold in substantially axial alignment therewith. means for guiding the plunger in its vertical reciprocations, said last named means including an opentopped substantially cylindrical casing surrounding said plunger in concentric relation therewith and in contact at its upper end with said neck mold and thimble or plunger ring assembly, means for supplying air under pressure to the interior of said cylindrical casing and thence to the interior of said neck mold and thimble or plunger guide ring assembly when the plunger is at the lower end of its path of vertical movements, and a vertically movable sealing ring mounted within said cylindrical casing and maintained by said air under pressure in air-tight contact at its upper end, with an inner peripheral wall of said neck mold and thimble or plunger guide ring assembly to prevent leakage of any of said air to the exterior of the casing at the place of contact of the latter with said neck mold and thimble or plunger guide ring assembly.

WALTER K. BER'II'IOID.