US2049788A - Glass feeder - Google Patents

Description

Patented yAug. 4, i936 TENT FFICE GLASS FEEDER Frank Il. 0. Wadsworth, Pittsburgh, Pa., assigner to Ball Brothers Company, Muncie, Ind., a corporation of Indiana Application August 28, 1933, Serial No.6 87,044

35 Claims.

My invention relates to an automatic glass feeder of the self-controlled-continuous-forcedflow type, which is broadly differentiated from the usual forms or species of flow feeding' devices by its capacity to establish and maintain an uninterrupted llow of substantially greater volume than can be obtained either by the action of gravity alone-as in natural flow feeders-or by the combined action of gravity and of an intermittently applied and periodically reversed forceas in reciprocating plunger and pressure-vacuum air types of apparatus-and one of the principal objects of my improvements is to thus greatly augmentthe rate of delivery of the molten material, both by increasing the mean effective eX- trusion pressure thereon, and by also eliminating the loss of time (and theother diiiculties) which is occasioned by the periodic stoppage and reversal` of theexpulsion movement thereof.

My improved type of feeder is further differentiated from those now in common use by its capacity to control its own action in such manner as to obtain a uniformity of operative performance, and secure a preadjusted or predetermined character of delivery, that is best adapted to produce a series of mold charges of the proper contour and weight for subsequent fabrication in they forming machine with which the feeder is to be used; and another important purposeof the present invention is to provide a method and a means of procedure whereby these results may be eifectively attained under a Wide variation in operative conditions.

Another object of my improvements is to pro- 2-.3 vide means for periodically varying and controlling the extrusion pressure-and the resultant rate of discharge oi the molten glass-for the purpose o1" shaping successive sections of the continuously flowing stream (without interrupt- 4;) ing the continuity of flow), prior to its separation into mold charges; and thereby obtaining a uniform series of progressively formed gobs or masses of material that may be readily severed from the oncoming stream (preferably at points .5 of reduced diameter) and delivered to the receiving apparatus in the best condition for the desired treatment therein.

A further purpose of these improvements is the provision of readily adjustable instrumentalities for manually regulating the relative variations in the rate-of delivery of the continuously flowing material during diierent portions oi each complete cycle of gob formation; and thus changing, when desired, the form or contour of successive stream sections, Without altering the mass or volume of the series of mold charges cut,y therefrom.

Still another object of this invention is the pro--` visionV of a special form of delivery orifice ring, which isV particularly adapted to cooperate with 5 other'features of 'my improved feeder construction in securing' the results that are characteristic of the combination as a whole; ory which may be used with advantage in conjunction with other analogous forms of apparatus.

Additional purposes and objects of the herein described improvements will become apparent, to those skilled in this art, from a consideration of the two exemplary embodiments thereof, which are illustrated in the accompanying drawings, and 15 in which:

Figure I is a longitudinal vertical section through the center of one form of my improved feeder assembly;

Fig. II is a horizontal section (on a reduced scale), on the double plane II-II-II of Fig. I;

Fig. III is a partial vertical section, in the plane of Fig. I, which illustratesan alternative construction of certain parts of the apparatus;

Fig. IV is a central vertical section-similar to that, of Figi-through a second illustrative embodiment of this invention;

Fig. V is a partialv plan view-on the plane VV--V of Fig. IV--of a portion of the construction shown in-k FiglIV;

Fig. VI is a reduced scale section on the horizontal plane VI-VI of Fig. IV;

Fig. VII is a second horizontal section on the plane VII-VII of Fig. IV; andv Fig. VIII is arvertical section, in the plane of Fig.y IV, showing a slight modication of a part of the construction depicted in that ligure. n

Referringiirst to the illustrations of Figs. I, II and III; l indicates a. forehearth, which extends out from'l the front of a suitable glass melting 4.0 tank (not here shown), and which is` conveniently enclosed by a sheet metal boot r2, that is supported, at its outer end, by vertical posts or standards 3 3. The forward portion of the forehearth chamber (C) is provided with aV removable bell B, which is inserted through the iloor of the forehearth, and is held up, in sealed engagement with the roof block 4, by means of a support plate 5 and the bolts 5 6; and the lower end of this bell is partially closed by a flanged .i0 metal ring l, which is held in position by the collar 8 and an insulating bushing 9, of asbestosbre or equivalent material, and which forms the delivery (ilow) orifice of the feeder. The upper end of the bell B is cylindrical in outline, but the lower 35 part is of rectangular shape, and is provided, on its rear side, with an upwardly tapered and transversely curved portion I0, which is recessed to form a lateral extension II of the bell chamber D. The lower end of the recess II terminates in a curved port or supply passage G, which passes through the wall of the bell B, and is in registry with a notch in the. adjacent side of a second bell member I2 that is inserted through the roof of the forehearth I and is held down against the oor of the chamber C by the plate and bolt elements I4-I5-I5, etc. The member I2 is hollowed out to form an accumulation chamber J, which is in communication with the molten glass in the forehearth extension through the side ports I-I-I-I, and the upper end of this member is provided with a tubular bolt I6, or" nichrome, or other suitable alloy, which extends up throughV the plate I4 and terminates in a central cup I1 thereon. The port G is controlled by a reciprocable plug valve I8, which extends through the roof block 4, and which is rigidly secured tothe metal collar I9 by the bolt 2U. The central stem of the collar I9 is closely engaged by a graphite or asbestos packing gland sleeve 2 I, which is mounted in the lower head of a cylinder 22,` that is bolted to the roof plate of the forehearth boot 2; and the upper end of this stem is secured, by the stud bolt 24, to the piston 25, which is adapted to slide in the upper portion of the said cylinder.

The space below the lower head of the cylinder 22-which is in open communication with the segregation chamber D in the bell B-is connected, by the pipe 25, withthe valve chamber of a reciprocable needle valve element 21 that is adapted to regulate the flow of compressed air from the conduit 28 to the chamber D; and the space above the piston 25 is connected, by the pipe 30, with the box of a double acting piston valve 3l, which serves to alternately establish communication between the said piston chamber and the pressure and vacuum conduits 32 and 33. This double acting valve assembly, is also coupled, by the pipe 35, to the cup I1, which communicates with the collection chamber J, and further serves to alternately connect the vacuum and pressure lines 33 and 32 to the said chamber J.

The reciprocable valve elements 21 and 3l are positively moved in one direction by the rotating cams 35 and 31 (which are mountedon a common driving shaft but which may be angularly adjusted with respect to each other); and areV moved in the reverse direction by the return springs 38 and 39. The stem 4I) of the needle valve 21 is pivotally connected to the lower end of a cam lever 4I which is fulcrumed on an adjustable pin 42 that may be moved up and down (in the slotted extremity of the lever 4I) to alter the throw of the valve head 21; `and the degree of opening of the valve-for any given setting .of the pin 42-may also be independently varied by the axial adjustment of the threaded Valve sleeve 43 through which the inner end of the valve stem d@ passes. The outer end of this stem carries a disc valve 45, which is normallyheld closed by a light spring 45, but which is adapted to be engaged, and opened, by an adjustable collar 41 on the stem 4S, when the valve head 21 is moved to its closed position by the return spring 38.

The functional operation of the above described parts is as follows: When the valve control elements are in the positions shown in full lines in Figs. I and II the Vupper end of the cylinder 22 is in communication with the compressed air line 32; the connected piston and plunger valve elements 25 and I8 are depressed until the adjustable stop nut 50, on the upper end of the stud bolt 24 is engaged by the upper head of the cylinder 22; and the supply port G is thereby substantially closed. The compressed fluid then ad- 5 mitted to the upper end of the chamber D (through the pipe and valve connections 28- 43-21-26, etc.) supplements the action of gravity in expelling the molten glass from the orice F, at a rate which is determined and controlled by the line pressure in the conduit 28, and by the adjustment of the valve elements 42, 43 etc., and also, if desired, by the setting of the hand valve 5I. During this stage of the operation the line 35 which leads from the accumulation cham- 15 ber J is connected to the vacuum conduit 33; and the reduction in pressure in this chamber draws the glass from the orehearth pool, through the inlet ports H, H, and rapidly raises the level of the molten material in the interior of the bell I2. 2O In order to definitely limit and preadjust the volume of glass thus admitted to the accumulation chamber, I provide an automatically operated check valve 52 (or 52a Fig. III), which acts to close the lower end of the pipe 35 when the 25 glass has reached a predetermined level, and thus arrests the further action of the vacuum (suction) on the inilowing material. In the construction shown in Fig. I this automatic closure of the check valve (52) is effected by a float 55, of clay 30 or other suitable material, which is adjustably connected to the valve 52Yby a threaded stem 55, that passes loosely through the opening in the tubular bolt I6. When the valve is closed by the lifting of the float 55, a hydrostatic balance is at 35 once established between the glass within and without the bell I2; and the elevated column of glass will remain in equilibrium in the nowvcompletely closed chamber (J) until the cam 31 acts to lift the piston valve 3|.

In the arrangement shown in Fig. I the cams 36 and 31 revolve in a clockwise direction; and these revolving elements are preferably so adjusted that the valve 21 will be momentarily closed-thus cutting off the application of pressure to the glass in the delivery chamber D before the valve 3i is lifted by the cam 31. The reduction in pressure on the glass above the delivery orice will diminish the rate of extrusion therefrom, and will produce a natural fnecking of the outiowing stream, without interrupting the continuity of its movement; and the degree of this necking action can be reguiated and controlled, by the length of the depressed portion of the ciam 35, and also by the adjustment of the collars 41 which determine the amount of venting action effected by the relief valve 45. Concurrently with, or immediately subsequent to, the establishment of this temporarily decreased pressure in the chamber D the valve 3I is raised to its upper position, by the cam 31, and the vacuum line 33 is thus put in communication with vthe top of the cylinder 22 (through the valve port 51 and the pipe 3b), while the pressure conduit 32 is concurrently connected to the line 35 through the 6fvalve port 53. The exhaustion of the air from the space above the piston 25, permits the latter to be lifted, by the unbalanced pressure of the atmosphere on its lower side, until the end 0.5 the piston bolt 25 engages the adjustable stop screw 5B, and thereby opens the supply passage G by a predetermined amount. The simultaneous admission of compressed to the pipe line 35 opens the closed check vialve 52, and thus subjects the glass in the chamber J to a predetermined pressure, (whichmay be adjusted and controlled by the hand valve iii) that will force it, through the passage G, into the segregation or delivery chamber D, more rapidly than it can escape therefrom throughl the delivery orifice F, and will therefore quickly raise the level of the glass therein;-this result being effected by making the area of the passage G substantially greater than that of the two inlet ports I-I-I-I, and also greater than that of the delivery orifice F, and by also so adjusting the valve controls 21-42-43- 5I and 6l, that the pressure in the line 2S is substantially less (at this stage in the cycle of operation) than that in the line 35.

In order to further control the automatic action of the feeder I have provided means whereby the valve 3l is returned to its normal full line position of Fig. I (independently of the movement of the cam Si), when the gllass has risen to a predetermined level in the delivery chamber D. As shown in Fig. I this means comprises a pair of contact rods $52 and 63, one of which (62) is adjustably mounted (for up and down movement) in an insulated bushing 'eii on the base of the cylinder member 22; and the other of which is fixed in an insulated block 65, that is secured to the floor of the forehearth boot These contact rods are connected, by thewires and 6l, to the terminals of a magnet coil which is in series with a battery (or other suitable source of electric current) lil; and which is adapted (when energized) to act on a soft iron armature Il, that is carried on a bell crank lever and is normally held away from the coil by the spring i3. The vertical arm of the bell crank lever 12 carries a stop pawl lli, which is adapted to engage the lower end of the valve stem 345, when the valve 3l is lifted by the cam 3?, and to hold it in its lifted position after the naised portion of this cam has passed under and beyond the contact roller of the cooperating cam lever M. But as soon as the rising column of glass in the chamber D comes into contact with the lower end of the rod 62 the battery cir-cuit through the elements 62- 66-58-61-65-63 is closed; and the armlature 'H is drawn downward and disengages the pawl 'M from the valve stern 365'; thus permitting the valve ii to be returned to its initial full line position by the spring This return movement again admits compressed air to the top of the cylinder 22 (therebydepressing the plug valve i8 and closing the passageway G) and applies vacllum to the chamber J to recharge the latter with a fresh supply of glass.

It will be apparent that the above described assembly Yof operative parts constitutes a selfcontrolled system, in which the volume of glass that is dnawn into the accumulation chamber J is automatically regulated by the adjustment or setting of the iioat with respect to the check valve 52; and in which the amount of molten material, that is transferred from this chamber J to the chamber D, also automatically limited by the Vertical adjustment of the contact rod 62; and that the termination of these charging and transfer movements of the glass is in no way dependent uponvthe mechanica?. action of the cam 31 land of its associated parts. This automatic self-control of the alternate vacuum and pressure actions on the glass in the chamber J permits the use of a very high vacuum during the accumulation period (which will in turn permit the use of relatively small inlet ports I-,I-I-I) and 'also the use of a high pressure during the transfer period-which will result in a very rapid recharging of the delivery chamber D-without any danger of unduly prolonging either of these operations and without requiring any exact timing, or adjustment of the cam Si. The only func,-

'tion performed by the latter is that of initiating;

the transfer movement of the glass from the previously filledl chamber J to the partiallyy emptied chamber D.

It will also be apparent that the total volume of,A` glass discharged from the delivery orifice during any one complete cycle of operative action-i. e.,I during each complete revolution of the cam as-` sembly 36-3D-is controlled in part by the combined gravity and air pressure on the mass of glass above thedelivery orice F, and in part bythe degree of throttling exercised by the plunger Valve i8 (which may be regulated by theI adjustmentr of the stop elements 5@ and et); and that the relative rate of extrusion of the molten material at successive intervals during each com-. plete cycle may also be varied and predetermined,

- by the adjustments of the valve elements .'l--li3--.

hearth chamber, and thus preventing the forma,-` tion of stagnant pools of material, and of local;- ized Zones of varying, or variable, temperature, This circulatory movement is produced by a rotating multi-{2)-lobed paddlewheel 11, of suit- I able refractory material, which is mechanically keyed to the inner end of a large hollow shaft of heat resistant metal (e. g. nichrome) that is re,- Volvably mounted in a graphite bushing 18 and is driven, from any suitable source of power, by the sprocket wheel and sprocket chain element 'M -8D. The rotation of this lobed wheel maintains a continuous current flow of molten glass in one direction-e. g. a counter-clockwise ow around the front of the bell B-and a reverse circulation of the heated gases of combustion above the glass surface; and this circulatory equalization effect may be assisted or supplemented, if desired, by the use of suitably position burners (not here shown) to supply additional heat to the forehearth chamber.

It is also desirable to provide means for blocking off the flow of glass to the forward end of the forehearth chamber for the purpose of removing and (or) replacing one or both of the bell members (l2-B), when the latter have been accidentally cracked or injured. As here illustrated this means comprises a vertically movable block 8l,-whose lower end is immersed in the glass, and whose width is somewhat greater than the gap between the inner ends of the two baliie or bridge blocks 82-82, that project laterally from the side walls of the forehearth chamber. The upper end of the vertically movable gate 8l extends up through the roof of the forehearth, and is preferably covered by a removable cap 83, which is bolted to the top plate of the boot' 2, and which serves to prevent any outflow of hot gases through the opening for the member 83.

The vertical adjustment of this gate--either for F bers l2-B, and the adjacent walls of the fore-l .f

in, andto, the block 8|.

Fig. III illustrates another means for arresting the withdrawal of air from the-accumulation chamber J when the glass therein has risen to a predetermined level. In this arrangement the automatic closure of the vacuum line connection 35 is effected by a vertically movable disc valve 52a, which is normally held open by a weighted armature 83, that is positioned below an electro-magnet coil 89, and which is closed by the lifting of this armature when the magnet is energized. One terminal of this coil is connected to the battery lead 97, and the other terminal to an insulated cover nut 99 which carries a vertically adjustable threaded rod 9|, that passes down through the tubular connecting bolt 56. When the rising column of glass in the chamber J comes in contact with the lower end of this rod (9|) the battery circuit is closed, through the contact 63 (see Fig. I) and 9I,and the check valve 52a is lifted to its seat, and is held in that position until compressed air is again admitted to the line 35 and forces it open against the pull of the electromagnet.

Figs. IV, V, VI, VII and VIII` illustrate another exemplary construction, which presents the same general features of functional action and performance as are characteristic of the previously described assembly (Figs. I to III) but which differs therefrom in certain details of structural form and arrangement of parts. In this structure the forward portion of the forehearth chamber (C) is provided with a raised shelf 94, which rests on the spacing blocks 95-95, and is engaged, on its lower surface, by ya cylindrical sleeve 96, that projects up through the forehearth floor and is removably held in sealed contact with the said shelf by the plate and clamp bolt elements 5ft-6a` The spacing v block and sleeve members -95-95 are so shaped and arranged as to form an elongated annular passageway G between the forehearth floor and the'shelf 94, (see Fig. VII) and the latter is provided with threeopenings 93, 99 and i539, which are respectively in registry with the two ends of the passageway G and with the upper end of sleeve 96.

The segregation or delivery bell member B consists of a straight cylindrical sleeve'whose lower end is seated on the upper surface of the shelf block 94 and Whose upper end is engaged by the chamfered roof block 4a, that is'held in position by the cover plate and clamp bolt .elements I 9 I-I 02 etc.;-the inner diameter, and the position, of the member B being such that its lower end embraces both of the openings 99 and |99. The opening I 99, which leads from the passage G to the segregation or delivery chamber D, is controlled by a vertically reciprocable plug valve |8a which passes upward through the roof block 4a, and is clamped at its upper end to a Vguide shaft I9a that is slidably engaged by a graphite bushing 2 Ia in the cover cap 22a.

'Ihe opening 98, in the rear part of the shelf 94, is of conical form and is covered by the lower end of a vertically reciprocable bell I2a, which is attached to the lower extremity of a guide 'rod |94, by the tubular bolt Ita and the auxiliary washer and bolt elements let-|95. This guide rod |94 is provided with a flanged collar |96, which is rigidly secured to the concentric bolt and rod members Ilia-|99, by the stud bolt and nut elements I9'l; and this collar is pivotally connected, at |98, to the inner ends of twin arm levers IDS-|99, which are fulcrumed, at II9, on

gages with a reinforcing bolt 86 that is secureda block |I| that is mounted to slide horizontally in suitable guide supports II4. The outer ends of the lever arm's I99-IIJ9 are flexibly connected to the slotted head of the guide shaft |9a by the cross bolt I|5, and carry an adjustable counterweight IIB, which serves to assist in normally holding the plug valve 8a in its closed position; and in concurrently holding the bell member I2a in its raised position. A second pair of rocking guide arms |I8-II8, are fulcrumed on xed trunnion supports IIS-H9 (which lie in the same horizontal plane as the trunnion support III) of the levers IBS-|99), and are pivotally connected to the levers |99 by the cross bolt |29, which is positioned midway between, and in line with, the pivot points |98 and II9. The arms II8-I I8 are also extended inwardly, beyond the trunnion supports II9, and carry a second adjustable counterweight IIal, which cooperates with the weight I I6 in holding the members I2a and IBa in the normal full line position of Fig. IV.

The above described system of levers and leverv connections (IIlS-I I8-I99-I Ill- I I II4--II9 and HID-constitute a straight line" linkage which will constrain the rod |94 to move up and down in a vertical line (or at right angles to the plane of the trunnion supports IIIl-I I9), and will thus eliminate the necessity for any guide bearing for the lower end of this reciprocable member. lThe upper end of the rod is secured to a piston IZI which slides up and down in a cylinder |22 and which may be forced down by the admission of compressed air that is admitted to the cylinder space above the piston through a double acting poppet relief valve |23. The downward movement ofthe connected members I2 I- |94 and I2a is limited by an adjustable nut 69a, whichV is carried by the upper end of the piston rod |94; and their upward movement-(which is accompanied by a corresponding reverse movement of the parts |8aI9a)-is controlled by an adjustable set screw 59a that is'carried by the head 22a and is adapted to engage the counter- 4 movement of the valve cam lever 4 la is utilized to g not only regulate the flow of compressed fluid to the interior of the bell B-and thereby vary and control the rate of extrusion from' the delivery orifice F-but is also used to open the valve |23 and thereby effect the transfer of a fresh charge, or quota, of molten material from the bell chamber J to the delivery chamber D. This action is effected as follows:

When the depressed, or cut away, portion of the revolving cam 36a passes under the roller on the cam lever 4 Ia, the l-atter is rotated in a clockwise `direction (on its adjustable fulcrum pin support 42a) by the pull of the spring 39a; and the valve 21a is moved towards its seat by the return spring 38a, thus momentarily reducing or relieving the air pressure in the delivery bell chamber D. The downward movement of the right hand end of the lever 4 la brings an adjustable contact screw |25 into engagement with the adjacent horizontal arm of a bell crank lever |26--which is pivotally connected to the upper end of the double disc poppet valve |23-thereby closing the atmospheric exhaust port |21, and concurrently opening the subjacent port connection to the conduit 32a. This valve movement admits compressed air to the upper end of the cylinder |22 and moves the connected piston-rodbell members |2|-||ll|-|2a downward; thereby shutting off, or throttling, com-munication between thel glass in the chamber J and the surrounding mass of glass in the forehearth chamber C, and simultaneously opening the port connection 99 between the passageway G and the delivery chamber D. The downward movement of the hollow piston rod lllil, establishes communication between a lateral port opening |28 in the side of this rod and the space above the piston |2|; and thereby admits compressed air to the interior of the depressed bell d20. The pneumatic pressure thus exerted on the now confined mass of glass, in the accumulation chamber J, forces the molten material, through the connected passages se-G-, into the segregation chamber D, at a substantially greater rate than it can be expelled from the delivery orice F;

and this transfer or recharging action will con,-

tinue until the glass in the bell B has reached a preadjusted height, which is determined and controlled in the following manner:

A vertically adjustable contact rod 62ais passed through an asbestos packed opening in the roof block la and is projected downward into the underlying delivery chamber D. The upper end of this rod is threaded and is engaged by a nut |30, which is rotatably mounted between insulating collars carried by laterally projecting lugs on the head 22a; and the rod is connected, by the wire 66a, with one terminal of an electromagnet coil 68a. A second contact rod 63ais extended through the side wall of the forehearth, and the adjacent portion of the spacing block 95, and is projected into the molten glass at the front end of the passageway G (just below the opening 19) and this rod is connected, in series with the battery 10a, with the other terminal of the coil 68a. This coil is provided with a soft iron armature core 1la, which is normally heldin its raised position by a compression spring 13a, and which carries an upwardly projecting beveled tooth 14a, that is adapted. to engage with the adjacent lower extremity of the-bell crank lever |26, andY lock the latten-and the attached valve |23-in its open position; i. e., in the position to which it is moved by the clockwise rotation of the cam lever dla. When the glass in the delivery chamber D has been raised to the level indicated by the dotted line in Fig. IV, the battery circuit is closed-through the coil 68a and its connections 62a-63a66a61a etc-and the armature 1|a is drawn down, thereby releasing the valve lever |26 from the locking dog 14a, and permitting the valve |23 to be returned to the full line (closed) position shown in Fig. IV,

lopen to the atmosphere through the restricted ,vent |32 (which is automatically closed when the pi'ston rod A|04 is moved down), and the glass in the forehearth chamber will then flow freely into theaccumulation reservoirthrough the large annular opening between the lower end of the raised bell and the shelf Ss-until it reaches the level of the molten material in the main pool. But it is ofcourse possible to provide an arrangement whereby the `vent |32 will be brought into registry with a port leading to a Vacuum line, When the piston rod |04 is raised to cut off communication between the port |28 and the top of the cylinder |22, and thus apply a suction to the glass in the chamber J, which will lift it to any desired height above the level of the glass in the forehearth chamber. Such a modified construction is shown in Fig. VIII, in which |33 is an internally grooved and radially perforated collar that is interposed between two packing rings, or gland members, which embrace the upper end of the piston rod |04; and 35a is a vacuum line connection which leads to an annular channel |35 that surrounds this collar and communicates with the radial perforations therein. When the first described arrangement (of Fig. IV) is used the maximum height of glass in the accumulation chamber is determined only by the level of glass in the main tank and forehearth extension therefrom; and this will remain constant as long as the main tank level is unchanged. With the last described arrangement (of Fig. VIII) the maximum elevation of the glass in the bell l2a will be preferably xed and determined by mounting a vertically adjustable contact rod Qta in the tubular piston shaft lll, and utilizing this, in conjunction with the contact 63a and a suitable battery (e. g. 1li or 10a) to close an elec'- tric circuitA through the electromagnet coil 89a), and thereby close the cut off valve 52a, when the rglass in the chamber J comes in contact with the lower end of the rod Sla; (see also description of the analogous control illustrated in Fig. III

supra).

In order to prevent the escape ofhot gases of combustion kthrough the opening around the upper part of the vertically movable bell l2a, I preferably employ a.cylindrical guard sleeve |36 whose lower end is seated on the shelf block 94, and whose upper end is engaged by a flanged cap 31, that is bolted down to the cover plate llll, andis flexibly coupled to` the piston rod collar |06 jby the metallic bellows |38. The lower portion of this guard 'sleeve is cut away on the rear side (as shown in Figs. IV and VI), to afford communication between the glass in the forehearth chamber and the space surrounding the bell Iza;

but the sides of the sleeve adjacent to the forehearth walls are engaged by bridge blocks Ullill, which rest on the shelf 94 and extend above the level of the glass pool, so that these blocks and the intervening portion of the sleeve |36 together form a dam that cut off the flow of molten material to that part of the forehearth enclosure in which the bell B is mounted. In Vorder to maintain this portion of the feeder assembly at the proper temperature `I provide suitable gas burners l ll-@lill etc. which are preferably mounted at different levels on opposite sides of the forehearth; and are so positioned (see dotted lines of Fig. VI) as to direct op-positely moving currentsof hot gasesl around the front of the vbell B, and rearwardly along the sides thereof,

through the openings between' the upper part of the guard sleeve and the adjacent walls, and into providing any special flues or chimneys for carrying away the burned gases of combustion from the forehearth, and facilitates the establishment and maintenance of uniform temperature conditions in all parts of the forwardly advancing quotas of glass which aresuccessivelyv supplied to the delivery chamber D and then expelled therefrom in a continuously flowing stream.

As already stated one of the features of my present improvements is the provision of a special form of a metal bushing or ring to define and determine the form and the area of the ilow orice F. The clay rings or collars which are ordinarily used for this purpose are subject to mechanical attrition, as well as tothe solvent action of the acid silicate constituents of the molten glass; and are also subject to injury in the plugging and unplugging. of the flow orifice at the beginning and the end of each weeks run; and all ofrthese actions tend to alter both the size and the shape of the opening through whichl the molten material is extruded, and thereby vary the cross sectional form or (and) the desired rate of delivery of the outiiowing stream. In order to avoid these diiculties, and at the same time avoid any substantial coooling of the stream surface by thermal conduction, Ivprovide a flow bushing (l or la) which has a very thin cross section, and is made of highly refractory metal, (e. g., nichrome or tungsten-molybdenum alloy) and insulate this ring from its collar support (8 or a) by a thick washer (9 or 9a) of asbestos or other non-conducting material. 'Ihe internal surface of this metal bushing (1 or' la) may be accurately machined to. a predetermined size and shape (of either circular, or elliptical or other desired cross sectional form), and may also be highly polished; and it will very quickly become uniformly heated to substantially the same temperature as that of the glass in contact therewith; so that it will not only serve to accurately determine the contour of the stream which issues from the delivery orifice (F) but it will also serve to diminish any retardation of the outflow by frictional resistance or by surface chilling.

In the normal opera-tion of my improved feeder, suitable means will be provided for severing the extruded and constantly flowing stream of molten material, at proper intervals, to form a succession of mold charges; and for delivering these successively cut off masses to the forming machine. This means may comprise a pair of movable shear blades (S-Sl-such as are indicated in dotted lines in Fig. I-which are prefer- Aably positioned quite close to the lower end of the delivery orifice F, and are operated at any desired time in the cycle of feed action-(preferably v1933, 653,081, filed Jan. 23, 1933, and 701,636,

led Dec. 9, 1933, but as this severing means forms no part of the particular feature of improvement herein set forth (except as complemental thereto) no further description thereof will be given.

I desire it to be understood that I have devised Vvarious structures and procedures `for producing and utilizing a continuously flowing stream of molten glassin connection with the formation of mold chargesv andvin whichthe flow of glass through thel orifice is never less than a gravity flow under the existing head and that various details of such apparatus and such procedure here illustrated and described but not claimed herein are claimed in my following copending applications 679,889, filed July 11, l1933, 687,042, filed Aug. 28, 1933, 687,043, filed Aug. 28, 1933, 716,626, filed Mar. 21, 1934, and 716,627, filed Mar. 2l, `1934.V It will bereadily understood, without further extended explanation, that all of the operative portions of Ymy improved feeder assemblies are so constructed andV arranged that they may be individually removed from the forehearth boot supports (2 and 3 or 2a and 3a) whenever it lis necessary to replace injured or worn out parts; and that the-,various manual adjustments, which may be used to vary and control the feeding ac,- tion, are all readily accessible to the operator in charge of the apparatus; and that these adjustments provide for Vavery wide range of change in the operative conditions, without aiecting the inherent self-controlled action of various cooperative elements. And with the preceding disclosure as a guide those skilled in this art will now be able-to understand and appreciate the functional characteristics and the operativea-dvantages of the herein described improvements; and will be able to devise various other alternative or equivalent structures which will be capable of practicing my present invention, and of attaining, in whole or in part as may be desired, the various objects and results that have been hereinbefore mentioned or are now apparent.,

What I claim is:

1. In combination in a glass feeder, aforehearth enclosing an accumulation chamber, and

a delivery chamber, a passage between said cham*- bers, means for controlling the delivery of glass from said foreliearth to said accumulation chamber, a device for controlling said passage. and means responsive to the glass level within said delivery chambers for controlling said device.V

2. In combination in a feeder for molten material, a forehearth, an accumulation chamber and a delivery chamber associated within said forehearth, aV passage `between said chambers, means for controlling the delivery of molten material from said forehearth to said accumulation chamber and from said accumulation chamber to said delivery chamber, and means dependent on the material level within said chambers for controlling said rst mentioned means.

3. In combination in a feeder for molten material, a forehearth, an accumulation chamber and a delivery chamber associated within said forehearth, a passage between said chambers,

means for drawing a quota of material from said' forehearth into said accumulationl chamber, means .responsive to material level within said accumulation chamber for controlling said rst lmentioned means, means for controlling said passage, and means responsive to material level Vwithin said delivery-chamber for controlling the operation of said passage controlling means.

4. In combination in a feeder for molten glass, a forehearth, an accumulator chamber and adeivery chamber associated with said forehearth,

`a passage between said chambers for delivering Vglass from the accumulator to the delivery chamber, a device for controlling said passage, and means for operating said device toclose Said passage and for drawing glass into said accumulator chamber while discharging glass from said delivery chamber.

5. In combination in a feeder for molten glass, a forehearth, an accumulator chamber and a delivery chamber associated with said forehearth, a passage between said chambers for delivering glass from the accumulator to the delivery chamber, a device for controlling said passage, and means for operating said device to close said passage and for drawing glass into said accumulator chamber while discharging glass from said delivery chamber and means responsive to the glass level within said chambers for controlling the operation of said first mentioned means.

6. In combination in a glass feeder, a forehearth, a delivery chamber having a submerged flow orifice associated with said forehearth and an accumulator chamber communicating with said delivery chamber, automatic means for controlling the delivery of glass from said forehearth to said accumulator chamber and from said accumulator chamber to said delivery chamber and means responsive to glass levels within said chambers for controlling said automatic means.

7. In combination in a glass feeder, a forehearth enclosing a delivery chamber having a submerged flow orifice and an accumulator chamber, a submerged passage between said chambers, means for reciprocating said accumulator chamber to establish and cut off communication between said passage and said forehearth, and a mechanically actuated device for opening and closing said passage.

8. In combination with a forehearth for molten glass having a ow orifice associated therewith, a closure for said forehearth, a gate extending through an opening in said closure and projecting into the glass contained within said forehearth, a shield secured to the outer surface of said closure and enveloping the end of said gate projecting through said opening and means extending through said shield for actuating said gate.

9. In combination in a feeder for molten glass, a forehearth enclosing a delivery chamber having a submerged iiow orifice, an accumulator, a passage between said chamber and said accumulator, means for reciprocating said accumulator, means for closing said passage and means for simultaneously subjecting said chamber to superatmosphericl pressure and said accumulator to sub-atmospheric pressure.

10. In combination in a glass feeder, a forehearth, a delivery chamber located within said forehearth and provided with a submerged flow orifice, an accumulator chamber, an inverted bell mounted within said accumulator chamber, a passage between said chambers, a device for opening and closing said passage, and counterbalanced means for reciprocating said bell and said device.

11. In a feeder for molten glass, a forehearth, a delivery chamber located therein and provided with a submerged flowy orifice, an Vaccumulator chamber, a submerged passage between said chambers, an inverted bell located Within the accumulator passage, a reciprocatory device located within the delivery chamber for controlling said passage. and associated means for liftingsaid bell as said device is lowered to close said passage and means for simultaneously subjecting the interior of said bell to vacuum pressure and said chamber to super-atmospheric pressure.

`12.*In combination in a glass feeder, a forehearth, a delivery chamber located within the forehearth and having a submerged orifice formed therein, means for segregating a quota of glass from said forehearth while a previously segregated quota is discharged from said delivery chamber and means responsive to glass level within said chamber for controlling the delivery of segregated quotas thereto.

13. A method of delivering a succession of mold charges from a pool of molten glass which consists in withdrawing and segregating a quota of glass from said pool, transferring glass from said segregated quota to a glass delivery position, controlling the amount so transferred by the level of `the glass in such delivery position and discharging such transferred portion while withdrawing and segregating a succeeding quota from said pool.

14. A method of delivering mold charges from a pool of molten glass which consists in successively withdrawing and accumulating quotas of molten glass from said pool, transferring a measured portion of each such accumulated quota to a body of glass maintained over an open flow orice and severing a mold charge from the stream flowing through such orifice while withdrawing and segregating a succeeding quota from said pool.

15. In combination with a forehearthhaving a discharge orifice, a delivery chamber above said orifice, an accumulator chamber and a passageway joining said chambers, means for subjecting the interior of said accumulator chamber to a vacuum pressure, means responsive to the glass level within said chamber for controlling the operation of said means, means for moving the glass in said accumulator chamber through the passageway and into said delivery lchamber, means for closing said passageway, means responsive to the glass level with said delivery chamber for operating said closing means, and means for subjecting the glass within the delivery chamber to super-atmospheric pressure.

16. In combination with a forehearth having a discharge orifice, a delivery chamber, an accumulator chamber and a passage joining said chambers, means for segregating a quota of molten glass within said accumulator chamber, means for moving glass from the accumulator chamber through the passage and into the delivery chamber, means for closing said passage, means responsive to the glass level within said delivery chamber for operating said closing means, and means for subjecting the interior of the delivery chamber to super-atmospheric pressure.

17. In combination with a forehearth for mol ten glass having a flow orifice therein, an inverted bell projecting into said forehearth and extending below the level of glass contained therein, means for reciprcating said bell, a ported sleeve surround said bell and projecting into the glass in said forehearth, a hollow member adjacent said sleeve and in communication with said bell and said orifice and means for alternately connecting said bell and said hollow member to a source of fluid pressure.

1S. The method of delivering molten glass from a pool of such material which consists in segregating a quota of material from said pool, transferring a portion of the segregated material to a delivery postion, controlling the quantity of material so transferred by the glass level in the delivery position, discharging said transferred material while preventing a reversal of fiow from 'the delivery position and segregating another quota from said pool simultaneously with the discharging of the transferred material.

19. The method. of delivering molten glass from a pool of such material which consists in segregating a predetermined quota of material from said pool, transferring a portion of the segregated quota to a delivery position, utilizing Athe level of material in the delivery position to control the amount of segregated material transferred thereto, discharging the transferred material while preventing a reversal of flow from said delivery position and segregating another quota simultaneously with the discharge of the transferred material.

2G. A pneumatic glass feeder comprising a forehearth having a flow orifice therein, a delivery chamber in communication with said flow orifice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a closure member for said passage, means for alternately connecting said accumulation chamber to sources of fluid pressure and vacuum, means for periodically connecting the delivery chamber to a source of fluid pressure and means for moving said closure member into passage-closing position each time said delivery chamber is connected to the source of pressure.

21. A pneumatic glass feeder comprising a forehearth having a flow orice therein, a delivery chamber in communication with said flow orifice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a closure member for said passage, means for periodically connecting said accumulation chamber to a source Y of fluid pressure to move material therein through the passage into said delivery chamber, means for periodically connecting said delivery chamber to a source of fluid pressure, and means operable when said delivery chamber is connected to pressure for moving said closure member into passage-closing position.

22. A pneumatic glass feeder comprising a forehearth having a flow orifice therein, a delivery chamber in communication with said flow orifice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a closure member for said passage, means for alternately connecting said accumulation chamber and Said delivery chamber to a source of fluid pressure, and means operable when said delivery chamber is connected to the source of pressure for moving said closure member into passage-closing position.

V23. The combination with a feeder for molten .glass comprising a forehearth having a iiow orice therein, a delivery chamber in communication with said fio-w orifice, an accumulation chamber communicating with the forehearth and havking a passage leading therefrom into said delivery chamber, .a closure member for said passage, means for alternately connecting the accumulation chamber to sources of vacuum and iiuid pressure to alternately accumulate a quantity of glass therein and discharge glass therefrom into said vdelivery chamber, means for periodically moving said closure member into said passage-closing position, means responsive to the glass level within -said delivery chamber for independently operating saidpassage-closure member, and means for Vperiodically connecting the delivery chamber to a source of fluid pressure.

24. The combination in a feeder for molten glass comprising a forehearth having a flow orice therein, a delivery chamber in communication with said cw orifice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a closure member for said passage, means for periodically connecting the accumulation chamber to a source of pressure to move material therefrom through said passage into said delivery chamber, means responsive to the glass level within said delivery chamber for closing the connection between said accumulation chamber and the source of fluid pressure, means for periodically moving said closure member into passage-closing position, and means for periodically connecting said delivery chamber to a source of fluid pressure.

25. The combination in a feeder for molten glass comprising a forehearth having a flow orifice therein, a delivery chamber in communication with said iiow orice, an accumulation chamber communicating with the forehearth and having a passage leadingftherefrom into said delivery chamber, a closure member for said passage, means for alternately connecting said accumulation chamber and said delivery chamber to a sourceof fluid pressure, means responsive to the glass level within said delivery chamber for automatically closing communication between the accumulation chamber and the source of fluid pressure, and means operable when said delivery chamber is connected to the source of fluid pressure for moving said closure member into passage-closing position.

26. The combination in a feeder for molten glass comprising a forehearth having a flow orice therein, a bell ,projecting Vinto said forehearth and extending below the level of the molten glass contained therein, a hollow member adjacent said bell and in communication with said orice, a iioo-r block having an opening therein for establishing communicationV between said bell and said hollow member, a closure member for said opening, means for reciprocating said bell and closure member, and means for alternately connecting said bell and said hollow member to a source of fluid pressure.

27. The combination in a feeder for molten glass comprising a forehearth having an orifice therein, a bell projecting into the forehearth and extending below the level of the molten glass contained therein, a hollow member adjacent said bell and in communication with said orifice, a floor block having an opening therein establishing communication between said bell and said hollow member, a closure member for said opening, means for reciprocating said bell and closure member, means for alternately connecting said bell and said hollow Ymember to a source of fluid pressure, and means responsive to the level of glass in said hollow member for independently closing the connection between said bell and the source of fluid pressure.

28. The combination in a feeder for molten glass comprising a forehearth, a hollow member supported in said forehearth and having a flow orifice therein, a spout projecting from said member, a stationary bell adjacent said member and having a series` of ports therein o-ne of which is in registration with said spout, means for alter'- nately connecting said bell to sources of fluid pressure and vacuum, means responsive to the level of glass within said bell for closing the connection to the source of vacuum, a closure member for said spout, means for reciprocating said closure member and means operable when said spout is closed for connecting said hollow member to a source of fluid pressure to expel the glass therefrom through the orifice.

29. The combination in a feeder for molten glass comprising a forehearth, a hollow member supported in said forehearth and having a iiow orifice therein, a spout projecting from said member, a stationary bell adjacent said member and having a series of ports therein one of which is in registration with said spout, means for alternately connecting said bell to sources of iiuid pressure and vacuum, means responsive to the level of glass within said bell for closing the connection to the source of vacuum, a closure member for said spout, means reciprocating said closure member, means responsive to the level ci glass within said hollow member for actuating the closure member reciprocating means, and means for periodically connecting the hollow member to a source of iiuid pressure to expel the glass therein through the orifice.

30. The combination in a feeder for molten glass comprising a forehearth having a flow orifice therein, a delivery chamber in communication with said oriiice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a gate normally closing said passage, means for periodically moving said gate to open said passage, means for applying an expelling force to the glass in said accumulation chamber to transfer glass therefrom through said passage and into said delivery chamber, and means responsive to the glass level within said delivery chamber adapted to control the closing of saidV gate.

3l. The combination in a feeder for molten glass comprising a forehearth having a iiow orifice therein, a delivery chamber in communication with said oriiice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a reciprocable closure member for said passage, means for reciprocating said closure member, a valve for controlling the operation of said closure member reciprocating means and adapted to connect said accumulation chamber to sources of fluid pressure, mechanical means for periodically operating said valve and means responsive to the glass level in said delivery chamber for operating said valve independently of said mechanical means.

32. The combination in a feeder for molten Y glass comprising a forehearth having a iiow orifice therein, a delivery chamber in communication w'lth said orifice, an accumulation chamber communicating with the forehearth and having a passage leading therefrom into said delivery chamber, a gate for closing said passage, iiuid actuated means forcontrolling the movement of said gate, means for introducing iiuid pressures into said accumulation chamber, a valve for controlling delivery of fluid pressures to said iiuid actuated means and to said accumulation chamber, mechanical means for operating said valve and means responsive to the glass level with said delivery chamber for operating said valve independently of said mechanical means.

33. The combination in a feeder for molten glass comprising a forehearth, a delivery chamber in open communication with a ilow orifice, an accumulation chamber communicating with the forehearth and having a passage leading rtherefrom into said delivery chamber, a closure member for said passage, fluid actuated means forreciprocating said closure member, a valve for connecting alternately said iiuid actuated means and said accumulation chamber to sources of liuid pressure and vacuum mechanical means for actuating said valve, means responsive to the level of glass within said accumulation chamber for independently closing its connection to the source of vacuum, means responsive to the level of glass within said delivery chamber for operating said valve independently of said mechanical means, and means for periodically applying an expelling force to the molten glass within said delivery chamber.

34. A method of forming a succession of mold charges from a mass of molten glass, which consists in successively withdrawing and accumulating quotas of molten glass from said mass, transferring glass from each such quota to a body of molten glass maintained over a iiow oflice,while proportioning the quantity of glass so transferred in accordance with variations in the head of glass of such body over said orifice, yand severing mold charges from the stream issuing from said orifice in timed relation with the accumulation of such quotas.

35. A method of forming a succession of mold charges from a mass of molten glass, which consists in withdrawing a quota of glass from such mass, shutting off communication between the quota so withdrawn and said mass and substantially simultaneously establishing communication between such quota and a body of glass maintained above a iiow orifice, delivering glass from such quota to such body to increase the head thereof over said orifice, shutting off communication between said body and the undelivered portion of said quota, and substantially simultaneously establishing communication between such portion of such quota and such mass, continuing the discharge of glass from said body through said orifice while replenishing such quota and repeating the cycle while severing the stream issuing from said orifice in timed relation with such replenishing operations.

FRANK L. O. WADSWORTH.

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