US1910354A - Molding machine - Google Patents

Description

May 23, 1933.

w. H. NlcHoLLs Er AL. 1,910,354

MOLDING MACHINE Filed Nov, 19. 1930 3 Sheets-sheet 1 ATTORNEYS May 23, 1933. w. H. NlcHoLLs ET AL 1,910,354

MOLDING MACHINE Filed NOV. 19, 1930 3 Sheets-521961'l 2 INVENTORS WlLLlAM H.NlC. O L ARTH R D. ZI

w if/zo ATTORNEY I May 23. 1933- w. H. NlcHoLLs ET AL 1,910,354

MOLDING MACHI'NE Filed Nov. 19. 1930 3 Sheets-Sheet' 3 10/ 90 V11 /fzWq/g. 10.

NVENTORS l WILLUMVI H. NICHOLLS ARTHU D, ZIEBARTH MQW AT QRNEYS Patented May 23, 1933 UNITED STATES PATENT" oFFlc WILLIAM H. NICHOLLS, OF OLD WESTDUBY, AND ABTHUR,D. ZIEBARTI-I, OF KEW GARDENS, `NEW YORK, ASSIGNORS, BY DIRECT .AND .-MESNE ASSIGNMENTS, TO Y WM. H. NICHOLLS C0. INC., OF. RICHMOND HILL; NEW YORKQA CORPORATION OF v NEW YORK MOLDING MACHINE .Application led November 19, 1930. Serial No.l 496,670. v

Important objects of the present invention are, to provide a roll-over molding machine of generally improved design; to provide such .a machine which will be efficient a-nd easy to operate; to provide a roll-over molding machine wherein j olting mechanism, mold-squeezing mechanism and patterndrawing mechanism are all embodied in a roll-over unit mounted for rotation about a lateral axis; to mount said unit so that it will be substantia-lly balanced about its axis of rotation and will roll over easily; to provide satisfactory means for operating the jolt; squeeze and draw mechanisms of said rotatable means by fluid pressure; to provide simple and satisfactory fluid pressure operated means for performing the roll-over operation; to provide means designed to facilitate the control of the fluid pressure operated means; to provide an improved roll-over molding machine of the trunnion type; to provide a roll-over molding machine whereina flask and pattern support and a squeeze head are joined together and supported in a unit by fluid pressure operated mechanism for squeezing and pattern drawing and wherein said mechanism in turn has a lateral trunnion which is mounted to rotatably support the unit; to provide in a molding machine improved fluid pressure operated means for mold squeezing and pattern drawing; and to provide other improved features which will appear hereinafter.` f

In the drawings, Fig. 1 is a plan View of the molding machine; A

Fig. 2 a vertical section taken on the line 2 2 of Fig. 1;

'Figa 3 a side view of the machine upon a smaller scale showing the squeezing operation.; Fig. 4 a fragmentary sectional View of the machine showing the pattern-drawing operation; i l e Fig. 5 an elevation of the machine looking toward the opposite side thereof;

Fig. 6 a section taken on the line .6 6 of Fig. 2; l 1

Fig. 7 a detail section taken on the line 7 -7 of Fig.`,2; f-

' Fig. 8 a front elevation of a portion of the machine; v

Fig. 9 a sectional View of thel roll-over control valve;

Fig. 10 a section taken on the line `10-10 of Fig. 9; and l l Fig. 11 a sectional vview of one of the chec valves ofthe roll-over control pipes.

The molding machine comprises broadly, a

pedestal l and a mold-forming roll-over unit 2. Said unit is mounted upon thepedestal for substantially balanced rotation about 1a lateral axis and includes all of the ymechanism required for jolting, mold squeezing and pattern drawing. These operations are. performed by means of fluid pressure, and fluid pressure is also employed for rotating the unit.,`

The pedestal' 1 comprises a hollow casting formed with a broadbase 3 which, in the present instance, is bolted as at 4 to a foundation 5. At its upper end the pedestal casting is formed with a long, horizontal bearing-box 6 which tapers toward one end, is formed within its larger end with a cylindrical bear* i ing surface 7 andwithin its smallerend with a materially smaller cylindrical bearing surface 8. Within the hollow upright portion of the pedestal is mounted a fluid pressure operated mechanism for effecting the rollover, as will be described hereinafter.V e

The mold-formingunit 2 includes aca-string forming arather long cylinder') which is normallyfupright and has a closed lower end 10 andan Vopen upper end. -At a point near the upper end the vcasting isintegrallyformed with a long, hollow,laterally extending trunnion 11 which extends through the bearing box 6 and is correspondingly tapered. I Cylindrical bearing'surfaces 12 and 13 formed upon the trunnion oppose the bearing surfaces 7 and 8 respectively of the bearing box, and anti-friction rollers 14 are interposed between said opposed bearing surfaces.k The rollers are confined endwise by ribs 15 formed upon the trunnion, by a plate 16 bolted to the free end of the trunnion and by a flat surface 17 formed upon the cylinder 9, around the root of the trunnion. The plate 16 abuts the outer end of the bearing box to prevent withdrawal of the trunnion, and a circular rib 18 formed upon the cylinder 9 fits around the opposite end of the bearing box. At its free end the trunnion is formed with a reduced nipple-like extension 19 having a bore opening into the interior of the hollow trunnion and forming part of a fluid pressure supply connection for vthemechanismsof the roll-over unit. f

` Near its lower end the cylinder casting 9'is integrally formed with a lateral. extensionv projecting in an opposite direction from the trunnion and defining a smaller cylinder 20 extending parallel to cylinder 9, and any oil chamber 21 between said cylinders. der 2O is closed at its lower end' and open at `its upper end andforms part of a jolt mechanism. vA hollow jolt piston 22 is fitted to reciprocate inl the cylinder and has a Hat table 23 cast upon its upper end and normally resting upona flat surfacev 24fsurroundin 'the open end ofthe cylinder. Saidtable orms a support for a mold flask and a carrier for a mold pattern. For the admission of fluid pressure to the jolt cylinder for the jolting operation said cylinder is formed with an admission port 25 upon itsy outerV or forward side, spaced upward from the lower end of the jolt piston in the normal position of the latter. Port 25 opens into an annular groove 26 formed in the piston,.and said groove communicates through apertures 27 with a cavity 25E-formed in thelower end ofthe. piston. Below the port 25 the cylinder is formed with an. exhaust port 29 normally closedl by the piston..

Fluid vunder pressure' is supplied to admis- *sion` port 25 through` a val-ve 30mounted upon the cylinder. Said valve is normally closed by the fluidpressure assisted by spring pressure if required and has a forwardly extending` stem 31 for opening it. A lever 32 is pivoted as at 33 to the casingl of the valve and has a depending armengageable with thek valve stem for pushing it inward: and adapted to be pressed by the knee of the operator. A tension spring 34 is anchoredy to the upper end of the lever and to the cylinder and normally holds the lever rocked'a-wayfromy the valve stem.l Lever 32.v also serves forthe retraction of a lock which is provided to hold the jolt piston in place when rolled over. Said lock comprises a bolt 35 slidable .a bore formed theifront of the cylinder and having a tapered inner end engageable in atapered keeper aperture formed in a bush-.ing 36 mounted in the piston.M At its outer end the bolt .has a pin and slot operative connection 37T with the lever at a point between the pivot of the lever and the spring connection, so that the spring normally holds the bol-t engaged inthe keeperaperture. When thev lever is rocked?, however for opening the valve 30 the bolt is "alsoretracted to permit jolting move'- rnen-t of the piston'. Preferablythere is suiicient clearance between the lever and the Cylinvalve stem to permit retraction of the bolt before the stem is engaged.

The jolt piston is prevented from turning, and. from moying too far outward under some circumstances by a bolt 38 screwed into the table 23, slidably fitted in a boss formed in the top wall of the oil chamber and extending down into said' chamber where it is provided with a stop nut 39 engageable withsaid boss. v Directly beneathfthe lbolt the lower wall of the oil chamber is formed with an aperture giving access to the nut and normally closed by a threaded lug 40. Similarly the lower end of the jolt cylinder has an aperture normally closed by a threaded plug 4l. Within the oil chamber is an oblique [in 42 which combines with the walls to-,form'a trough, when inrolled over position, and' one or more oil ports 43 leadf from saidtrough to the -interior of the jolt cylinder for lubrieating it. Anfoily pipe'43 leads from the oil chamber to the interior of the cylinder 9.

Slidably fitted inthe large cylinder 9 is a long, hollow, cylindrical plunger 44 which forms a shiftable supportfor a squeeze head t 45. The upper. end of the plunger is closed by a head 461 bolted thereto as at 47 and its lower endis closed. by a piston-like head 48 yfitted inthe plunger and secured to it by screws 49.- At a medial point in the length of theplunger a'pistoir-l-i-ke partition disk 50 isvfitted rin the plungerand secured by screws 5l. Astem'Q extends through the plunger along the axisther'eof. At its lower end said stern-is fixed` to. the-closed end of head 46 and hasa pistonv 56 fixed to it and having a. sliding fit in the plunger. Said piston has an aperture through which the end Vof the stem is passed and the 'stem is threaded and has twonuts 57 and 58 screwed upon it and tightened againstl opposite lfaces of the piston. At a point between the lower plunger head and the partition disk or piston 50, and preferably nearer the. latter, another piston 5.9 is fixed tothe stem and has a sliding fit in the plunger, the stem being passed through an aperture inthe piston, threaded and having two nuts 59 screwed upon it and tightened against the opposite faces of the piston.

Pistons 56 and 59 have packing engaging the plunger, and the plunger pistons 48 and 50 have packing engaging the stem, to prevent leakage. l'Ihe'interior'of the plunger is divided by the various pistons into three fluid expansion chambers 60, 61 and'62. vChamber 60 is located between the upper plunger head 'les 'lis

tion. i Admission of sufficient fluid pressure to' "1 a threaded bore in the free stem has a fluid `passage 63 extending the length thereof, and lateral ports 64 and 65 through which said passage communicates with the chambers 61 and 62 respectively. The upper end of passage 63 is closed by a plug and its lower end has a fluid supply and exhaust connection. A port 66 leads through the plunger head 47 into the chamber 60 and also has a fluid supply. and exhaust connecehamber will cause the plunger to move upward with reference to Fig. 2, since the plunger is movable in cylinder 9 while the piston 56 is fixed. Thereby the squeeze head 45 is moved farther away from the Vflask support 23. This movement is automatically limited by a locking means comprising a hook 67 which is pivoted, as at 68, to the under side of the plunger head 47 and is adapted to gravitate into engagement with a loop 69 formed upon the nut 57, and anchor thereto. Admission of fluid pressure to the chambers 61 and 62 through the stem passage 63 and ports 64 and 65 acts upon the plunger pistons 48 and 50 to force the plunger downward.

Thereby the squeeze head is moved toward the flask support for mold-squeezing and for holding the flask in place during the rollover operation.

The mounting for the squeeze head 45 includes a lateral arm 70. An ear 71 Vis formed upon the plunger near the upper end thereof and the arm is formed with a forked end which straddles said ear and is pivoted l thereto upon a pin 72 for lateral swinging of the squeeze head into and out of register with the flask support. The squeeze head is provided with an upwardly extending central shank 7 3 which screws upward through end of the arm and supports the squeeze head for vertical adjustment. A hand grip 74 is formed .upon the free end of the arm for swinging it, and the pivoted end of the arm is formed with a stop lug 75 engageable with the plunger to limit the swing of the arm which brings the squeeze head into register with the flask support.

Within the hollow pedestal 1 is a mecha nism for effecting theroll-over of the moldforming unit upon the trunnion 11. This mechanism includes a shaft 76 mounted in bearings 77 near the base of the pedestal. A sprocket wheel 78 is fixed to said shaft, an-

other sprocket wheel 79 is fixed -to the trunnion and a drive chain 80 is trained over said wheels. An adustable device 81 is provided for tensioning the chain. Between the `trunnion 'and shaft7 6 extends a cylinder Said cylinder has a closed upper endl formed with an ear 83 which isvpivoted upon a pin 84 fixed within the pedestal. A piston 85 is fittedin the cylinder and has a piston rod 86 extending downward through a removable head 87 closing the lower end of' the cylinder. At its lower end the piston rod is operatively connected to a crank 88 fixed to shaft 76. The cylinder has fluid admission and exhaust connections .at its opposite ends for reciprocating the piston. A valve 89 is provided for controlling the fluid pressure in the cylinder. i

Valve 89 comprises a body or base 90 and a cap 91 defining a chamber 92 and bolted to each othery and to a plate 98. The latter covers an opening in the side of the pedestal nearest the roll-over unit and is bolted to the pedestal. A valve seat 94 is formed upon the valve body within the chamber 92, and a disk valve 95 is rotatably mounted upon said seat and is formed withtwo ports 96 and 97 spaced around its axis, and with a radial cavity 9.8 opening inward toward the valve seat. A stem 99 for rotating the valve is rotatably fitted in a bore formed in the valve body and is fixed to the valve. An axial passage 100 formed in said stein communicates with the valve cavity 98 and places the latter in communication with a lateral .exhaust port 101 formed in the valve body.- The stem extends outward through an opening in the valve-supporting plate 93 and is provided with an operating handle 102 vforming two` oppositely extending arms' having eyes vat their extremities. The valve seat is formed with two ports 103 and 104 spaced around the valve axis a less degree than the valve ports 96 and 97. A flexible tube or hose 105 connects port 103 to the upper end of the cylinder 82 and a flexible tube or hose 106 conneots port 104 to the lower end of the cylinder. Y Connected to the valve cap 91 is a fluid supply pipe 107 opening into the valve chamber 92. A spring 108 interposed betweenv the cap and thevalve assists the fluid pressure lto hold the valve upon its seat. Each of the tubes and 106, adjacent its connection with the cylinder, is provided witha check valve 1,09 opening toward lthe cylinder but exhaust of the fluid back to the tube.

l/Vhen the handle v102 is rocked in one direction valve port 96 is brought into register with port 103 for supplying fluid pressure to the upperend ofqcylinder`82 and the valve cavity 98 isregistered with port 104 forthe exhaust of the cylinder below the piston 85. Thereby the piston is forced downward to cause rotaton of the roll-over unit to rolled over positionV through the operative connection between the piston and the trunnion 11. lllhen the handle is rocked in. the' opposite direction valve port 97 is registered with port 104 and valve cavity 98 is registered with port 103 for admission 0f` fluid pressure 'to the provided with a bleed port 110 permitting lovver end of cylinder 82' and exhaust of: pressure from Vthe upperY endet' .the Cylinder. Thereby the piston is forced uplwardtofroll yback the roll-overunit .to normal position.

Movement of the valve disk to etherof said positions is limited by engagement? oza stop pinlll with the ends of a slot 112 formed in the disk. The roll-over movement of :the unit is limited by Contact of a stop 113 formed upon the plunger 44 Withone side of an elongatedzstop rib 114 formed upon the pedestal. Roll back movement of theunitis limited by contact of a stop llormed upon cylinder with the opposite side of the-rib 114.

Means are providedor convenient operation of the valve89 from the front of the machine. .This meansl includ-es a: horizontal rock shaft 116 extending fore and aft above the roll-over unit. Saidv shaft is mounted inbearings supported byan L-shaped bracket 117 supported upon the bearing box 6'; Centrally fixed to the rear end of shaft 116 `is-a cross bar 118 similar tothe valve handle 102 and having its kends operatively connected to the ends of the handle by pull-cords119." A similar cross bal" 120 iscentrally fixed to the opposite endv of the :rock shaft andhas tWo pull cords 121 depending Vfrom its ends and provided with handles '122 Within 'the reach of an operator. `Tl1e cross arm 120 is normolly held horizontal'by a tensionspring-123 which is anchored to a centrally depending Alug formed upon the lcross arm and to a depending ear 124 carried bythe bracket 117.

Mounted upon one side of the large cylinder 9 is a valve 125 for controlling the squeezing and pattern-drawn operations of the rollover unit. This valve is substantially a duplicate of valve 89 and a detail showing and description of it is thought to be unnecessary. A pipe 126 leads from 'the valve tothe lower end of the stem 52 and the passage 63' therein. Another pipe 127 leads from the valve-"to lthe port 66 at the upper end vof the plunger 411i Pipe 127 is formed in telescoping sections to permit movement of the plunger 'and is suitably packed to prevent leakage, The valve has an operating handle 128.

Fluid, preferably air under' pressuref'is' supplied to the jolt valve 43(7) 'andthe squeeze and drawvalve 125 `through vthe hollovv'trunnien 11. A main supply pipe129'is c'onnected to the nipple 19 of the plunger by a ysuitable stuffing box structure 130,1 and apassage, 131 formed in cylinder 9 leads obliquelyout- Ward. 7 A pipe 132 connects said port to valve 125, and afbranchpipe lconnects pipe 132 to the jolt valve 30; `Pipe107 which supplies the'valve 89 for the roll-*over and roll-back operations, leads from the supply pipe 129.` The machine is operated as follows Valve 125 is manually operated to admit air which is supplied through the trunnion, into pipe 127 and thence to port 66 andthe'uppermost chamber of the plunger. This operation 'of the valve also vents the lplunger chambers Gland 62 ytoiatmosphere through portsf64 and-65,fpassage 63,-pip'e126 and the exhaust port 'of thevalve. Consequently the air admitted 1 into 'chamber 60 elevates the plunger *and increasesnth'e clearance between the squeeze'head 45 fand-,the llaslilsupporting tablea 23.v ALoek 67:'automatically limits the upward movementr olil the plunger. The squeeze headisswung laterally out of regster with the table and a flask l2" is placed upona pattern plate P which is supported by the =table` 23 and secured thereto Iasindicated at 134. The pattern plate carries a pattern P projecting upward into the flask. In order to :holdv the'vflask. true upon the pattern: plate the plate is provided with :the usual retaining pins'135 which projectithrough apertured ars'lformed upon."r/)fppdsitesidesof the flask. yHaving v-p'osit-ionedfthe flask it is charged with sand 'and'thexjolting operation issprforned zbyv pressing y the 'lever 32l inward: '.'lhisl retractsv the bolt f 35 and". opens the' valve 30 for theadmi'ssion ofcompressed air to Ithe lower end :of the jolt cylinder through ports-'25- and 27 .Therebythe jolt piston "is raised until-it bpensthe; exhaust port T29 whereupon it vdrops for 'jolting the sand. vVillleni this has been repeated sufliciently .the lever is released,4 whereupon the1 valve 30 is automatically closed and the'bolt 85de automatically projeted'invvard by the; contrac-tionv ofspringy 34 for-locking the jolt piston. u v

fAsqueez'e boa-rdror bottom board B is next placed upon 'the s-ndin the'flaslr; squeeze head' 45 is swung backV into lregister w'ith the Hasln-'and .valve 125 is' operated for the moldsqueezing bperationr vThrough said valve compressedz air7 supplied through the trunn-ion';1-is r'admitted to pipe *126' and-thence through stenrpas'sage63 and ports 64 and totplfunger.l chambers (S1-and 62. Here said-air operates upon'pisto'ns 50 and 48 fto foree-'the".plunger' oWnWard' and press the squeeze head l'145 f against @the presser board B to squeeze the mldi "It Wi xbe'sunderstood that .tbezva-lvef-125 in f itsh mold-squeezing adf `iustment'vents thejc'hamber 60 to atmosphere; The pressure developed in chambers 61 and'- 62 eiertedlu-ponth'e cooperatingjpistons 48 and 50 -causesi an effective 'squeezing =By the yprovision of tandem expansion chambers'-and4 pistons, iasshown,"'the piston and"cylinder diameters are greatlyreduced andl themecha: nism is givenfan elongatedfo'rm suitable for supporting the jolting mechanism and the squeeaefhead in spaced relation and for carrying the trunnio'n- 11;V

I Vhile 'holdingl the partsfinsquee'zing position the 'valve 89 '-is operated for the roll-over by pulling the appropriatehand-le A122Qat the front of the' machinef 'lhe'` -valvel admits com'- pressed'air ytor theupper-end of cylinder 82 and exhausts 'it 'from the lower'end thereof I said spaces must be vented. The

to cause the roll-over of the mold-forming unit 2 and the inversion of the flask. During the roll-over the flask and mold are held clamped in position by the squeezing mechanism and, at the conclusion of the roll-over the weight of the flask and mold rests upon the squeeze head which then serves as a flask support.

Vhile maintaining the rolled over position of the unit 2 and the flask the valve 125 is operated for causing the pattern-drawing operation. Air is thereby exhausted from the plunger chambers 61 and 62 through the ports 64 and 65, passage 63. pipe 126 and the valve exhaust port. Thereby the plunger 14 and the squeeze head 45, with the supported flask and mold, are permitted to gravitate away from the table 23. Since the table carries the pattern P the latter is withdrawn from the mold by the recession of the squeeze head. In rolled over position the hook 67 lies in an inoperative position upon the plunger head 46 to permit the greater movement of the plunger for pattern drawing. The

'f flask is next removed from the inverted squeeze head, and the valve 89 is operated from the front of the machine by the appropriate handle 122 to cause the roll-back movement of the mold-forming unit. rlhe valve does this by exhausting air from the upper end o-f cylinder 82 and admitting compressed air to the lower end of the cylinder.

The mold-forming unit is designed and supported for substantially balanced rotation so that little power is required for the roll-over and roll-back movements. These movements are cushioned by the restricted exhaust of air from the cylinder 82 through the bleed ports 110 in the check valves 109.

It is obvious that the volumes of the plunger and cylinder spaces between pistons 50 and 59 and between piston 48 and the lower end of cylinder 9 will vary in the reciprocation of the plunger. Consequently lower space, with reference to Fig. 2, is vented directly to atmosphere through ports 136 in the closed end 10 of the cylinder, and the upper space is vented through ports 137 in the plunger which open into longitudinal grooves 138 formed in the inner walls of the cylinder .and lead into said lower space. The plunger is held against turning in the cylinder by a set screw 139 threaded through the cylinder and engaging in a longitudinal slot 140 formed in the outer wall of the plunger.

Vhat we claim is:

1. A molding machine comprising a rollover unit including a flask support mounted for shifting to jolt the sand in a supported flask, fluid pressure operated means to shift said support for jolting, locking means to hold said support against shifting, manually operable means operatively connected to said locking means and said fluid pressure operatedmeans to release the locking means and cause Athe ,jolting operation, and means to automatically applythe locking means after the jolting'operation; and a mounting for said'unit supporting it for rotation to roll over the flask.

' 2. A molding machine comprising amoldforming roll-over unit including a pair of opposed flask supports spaced apart to accommodate a flask between themr and permit it to rest uponV one lof said supports, fluid pressure operated iolt mechanism to vertically shift the latter support for vjolting the sand in the mold, locking rmeans to prevent said vertical shifting of said support, lcontrol means for the jolt mechanism, manually operable means operatively connected to said locking means. and to said jolt control means for releasing the vlocking means and causing the jolting operation, means to automatically vapply said. locking means at the conclusion of the jolting operation, pattern-holding means carried by said latter flask support, and means to move one support toward the other to squeeze the interposed mold in the flask and hold the flask during the roll over; and amounting for said unit supporting it for rotation to roll over the flask and transfer its weight. fromone support to the other, one support being shiftable away froml the other for drawing the pattern and `said locking means preventing dropping of the jolt-operated support when the pattern l drawing occurs.

'3. A molding machine comprising a pair of opposed flask supports; a fluid pressure operated mold-squeezing and pattern-drawing mechanism connecting said supports and supporting them in spaced relation in a unit; a trunnion carried by said mechanism and extending laterally from it; and a mounting for` said trunnion supporting said unit for rolling over to vinvert the flask and transfer it from one support'v to the other. i

4. A roll-over molding machine comprising a pair ofopposed flask supports; avfluid pressure operated mechanism supporting said flask supports in spaced rela-tion in a'unit, said mechanism being operablefor shifting one llasksupport toward the other supportv for mold squeezing; and a mounting for said fluid pressure operated mechanism supporting the unit through the medium of said mechanism for rotation about a lateral axis to roll over and invert the flask and transfer its weight from one support to the other.

5. A molding machine comprising a pair of flask supports; a roll-over unit comprising a telescoping fluid pressure operated mechanism supporting said flask supports laterally offset therefrom in opposed spaced relation to receive a mold flask therebetween, said mechanism being operable by fluid pressure to longitudinally contract it and move lli onel of. said supportsl toward the other to squeeze ay mold in an interposed ilask and being operablegto longitudinally extend `it to move one of said .supports awayv from the other for pattern-drawing; `.and amounting for said mechanism supporting the unit through themedium o'f'said mechanism for rotation about a lateral axis to roll over the flask and-transfer the weight of the flask from one of said supports tothe other. :64A molding machine comprising a pair of flasksupports; av roll-over unit comprising a. fluid pressure operated mechanism supporting said'l'lask supports laterally offset therefrom in opposed spaced relation to receive a Vmold fla-sk therebetween and comprising means forming a plurality of iuid pressure chambers in tandem relation and each having a shiftable Wall operatively connected to one of therlask supports, said Walls being shiftable in unison in the same direction by fluid pressurevapplied in said chambers to the same side of each Wall to move said operatively connected lask support toward the other support for mold squeezing and shiftable in the opposite direction to move one of said supports away from the other for pattern-drawing; and a mounting-for said mechanism vsupporting the unit through the medium of ,said mechanism for rotation about a lateral axis to roll over the flask and transfer the vWeight of the lask vfrom one of said supports to the other.V

7. A molding machine comprising a rollover unit including a pair of opposed flask supports spaced apart to `accommodate a {ias-k between them, mechanism'to shift one of 'said .supports toward and from the other for ,squeezing and releasing the mold, and gra-vityoperated locking means to limit the movement of said shiftable support away from the other support; and amounting for said unit supporting it for rotation to roll over the flask, said locking means being releasable by :gravity when the unit is rolled over to permit `greater movement of the shift` able support away from the other support for pattern drawing.. v

In testimony whereof We hereunto alix our signatures this 15th day 'of November, 1930.

WILLIAM NICHOLLS. ARTHUR D. 'ZIEBRTL

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