US2278815A - Casting machine - Google Patents

Description

April 7, 1942. H. c, -W|NKEL CASTING MACHINE Filed Au 28; 1946 5 Sheets-Sheet l' April 7, 19428 H. c. WlNKEL CASTING MACHINE Fi led Aug. 28,1940

5 Sheets-Sheet 5 g gg g 2,22% gE;5225222222522Ea BEBEUEQEEQEEEEQEE CEEEELEEEEEEEECa 3 mw 1: I: Q i, \m. 1 L l 1 Patented Apr, 7, 1942 UNITED STATES v PATENT" OFFICE ML ZTZTIZTM. Application August 28 1940, Serial Na. 354,495

9Claims.

This invention relates to casting machines and more particularly to automatic machines for casting or molding grids for storage batteries.

The machine of this invention is intended for continuous operation for quantity production of battery grids and is adapted to consecutively .present closed molds to the usual metal pouring device whereby the consecutive molds are filled and then moved past a discharge. station where each mold automatically opens and the grid is discharged therefrom. The discharged grids are automatically arranged in segregated groups so that the grids from each mold are assembled in a single group.

It is an object of the invention to provide a rotary molding machine having improved operating, features particularly adapted for high speed quantity production and in which the parts of the molds may easily be separated for cleaning and spraying in the usual manner and wherein the molds are particularly adapted for high speed quantity production in that they are constructed to enable complete and uniform filling of the molds without the forming of unduly large fins on the grids. The molds are also construct ed to equalize the, pressures therein so that the back pressure of trapped gases is just sufllcient to counteract the pressure of the metal when all of the passages of the mold are completely filledand without allowing the passage of the molten material into the gas compression spaces. The molds are, therefore, completely filled to form perfect strands in the finished grid and at the same time the grid may easily be removed from the molds.

In casting grids for battery plates in which the strands of the labyrinth-like plate are elongated and very small in diameter, it has been very diflizult to cause the molten metal to completely fill the mold cavity and form perfect strands throughout the plate and without forming objectionable fins on the strands. This is due to the small size of the grooves in which the strands are molded and the fact that the mold contains air which usually vented therefrom n in) It has been found that, by the proper distribution of air compression chambers or grooves closely associated with the strand cavities of the mold, air vents may be entirely dispensed with and a desired flow of metal may be obtained so that perfect grids may .be formed without fins on the strands and without permitting any of the metal to enter the compression grooves. this means the grids are perfectly formed and easily ejected from the molds and the molds do not require frequent cleaning. This is an important feature of this invention, as it enables the use of a simple high speed molding machine suitable for quantity production and with a minimum number of defective grids.

Another object is to Provide a "molding machine of few parts, all easily accessible for repairs or adjustment and in which the sections of any of the molds may easily be separated for cleaning or spraying, or one section may be completely removed from the machine by merely releasing a latch and bodily removing the section without the use of tools, thereby providing free access at any time to the mold cavities of any of the molds irrespective of their position on the machine.

Battery grids are cast in integral pairs, that is, two grids in a single casting with an outstanding terminal lug on-each grid. The terminal lugs are oppositely disposed on the double gridand it has been found that, if these lugs can accurately be cast without fins and with clean-cut edges, they may be used as locating without fins are provided.

through air passages. The metal very often flows into these air vents, therebynot only causing fins but also tending to lock the grid in the mold and prevent proper automatic ejection of Another object is to provide, in a continuously moving mold, means to enable the molten metal pouredinto the moving mold from a fixed pump or other suitable means to be properly distributed in the moving mold without being spilled therefrom.

Other objects will be apparent from the specification and the appended claims.

line substantially corresponding to line 22 thereof.

Fig. 3 is ,a side elevation partially in section of the grid assembly device and is a continuation of the left-hand end of the machine as illustrated in Figs. 1 and 2.

Fig. 4 is a top view of the grid assembly table illustrated in Fig. .3.

Fig. 5 is an enlarged top view of one of the fixed mold sections and the grid ejectorassembled therewith, a portion of the mold element being shown in section for purposes of illustration.

Fig. 6 is a fragmentary face view of one of the mold sections and illustrates the mold cavity for forming the grid and the compression spaces for gas between the channels forming the strands of the grid.

Fig. 7 is a diagrammatic side elevation of one of the double grids which may be molded by the mold construction shown in Fig. 6.

Fig. 8 is an enlarged horizontal detailed section through the closed mold after the metal has been poured therein and is taken on a line substantially corresponding to line 8-8 of Fig. 6.

Fig. 9 is an enlarged vertical section through the closed and filled mold and is taken on a line substantially corresponding to line 9--9 of Fig. 6.

Fig. 10 is a fragmentary face view of a slightly different type of mold particularly adapted for forming a grid with so-called staggered strands and constructedto provide a corrugated bottom fin having considerably increased strength without increasing the thickness thereof so that the grid may more easily be handled without distorting the fin.

Fig. 11 is an enlarged fragmentary sectional view through a closed and filled mold of the type shown in Fig. 10 and is taken on a line substan tially corresponding to line ll-|l of Fig. 10.

Fig. 12 is a vertical section through the closed and filled mold and is taken on a line substanwithout fins on the grids.

Fig. 16 is a perspective view of the sealing plug shown in Figs. 14 and 15.

Referring to the drawings in detail, the embodiment illustrated comprises a substantially circular frame I supported on suitable legs 2. The frame I is provided withan upwardly extending hollow stub shaft 3 rigidly secured in the frame, on which is rotatably mounted a table 4, on which'table a plurality of radially positioned grid molds are mounted for rotation therewith. The table 4 is provided with a gear 5 secured thereto and in mesh with a pinion 6 on a vertical drive shaft 1. The table 4 is driven by means of a motor 8, which latter drives the shaft 1 through a speed reducer 9 to which the motor is operatively connected by means of a belt I 0 on suitable pulleys. The table may, therefore, be continuously operated in the direction of the arrow in Fig. 1. The table 4 is provided,'adjacent its outer edge, with rollers or casters H adapted to rest on a circular track [2 on the frame I. 1

Around the edge of the table 4 are mounted a plurality of sets of upwardly and outwardly extending brackets II. In the present embodiment there are eight sets of these mold supporting brackets distributed around the table. However, only five of these sets'and the molds supported thereon are shown in Fig. 1, as all of the sets of brackets and associated molds and operating mechanisms therefor are identical. A suitable mold is mounted on each set of brackets and comprises an inner mold section l4 fixedly secured to the brackets l3 and provided adjacent each side of the mold cavity with an outwardly extendin guide rod or stud IS, on which latter is slidably mounted an outer mold section I. The outer section l6 may, therefore, be freely moved on the studs l5 to and from the inner section 14 by an operating mechanism which will now be described.

The mechanism for operating each mold comprises a U-shaped yoke II, the outer transverse span' Ila thereof normally resting in notches It in a pair of outwardly extending brackets l9, which latter are rigidly secured to the outer face of the outer mold member Ii. Spaced collars [1b are secured on the spans 11a in order to prevent v lateral movement thereof and in order to enable accurate closing of the mold. An elongated guard 29- having angularly inturned ends 2| is secured to the outer ends of the brackets 19 and may be used as a handle for removing the outer mold member l6 from the guide rods I5 when the loop I! is raised out of the notches and above the mold to the dotted line position shown in Fig. 2.

The outer mold section may, therefore, easily be removed at any time by merely raising the yoke or so-called bail, or may be moved outwardly on the guide rods l5 until engaged by the loop span "a in order to separate the mold sufliciently to enable cleaning or spraying of the faces of the mold sections. It'is desirable that, during the automatic operation of the machine, the molds should separate only sufliciently to enable ejection of the grid for the reason that too great separation chills the mold.

The inwardly extending arms of the yoke ll are connected to a cross bar 22 to thereby form a loop extending completely around a mold. The bar 22 is provided ith a rearwardly extending rod 23 pivoted at 24 on a lever 25, which latter extends through an opening in the table 4 and is pivoted thereon at 26. A compression spring 23a is mounted on the rod 24, which latter is slidable in the pivot of the lever 25, and the spring may be adjusted by means .of the nuts shown so that the mold sections may be clamped together with a suitable resilient pressure. The lever 25 is provided at its lower end with a spherical cam follower 21, which follower is.

adapted for engagement with upwardly extending arcuate cams 28 and 29 on the frame I. The

cams 28 and 29 are concentrically positioned, and

in Fig. 2 the mechanism at the left-hand side of the view illustrates the follower in engagement with the inner surface of the cam 28 to thereby hold the associated mold in open position, while at the right-hand side of Fig. 2 the follower 21 is in engagement with the outer surface of the cam 29 to thereby hold the associated mold in closed position. The moldshown at the left of Figs. 1 and 2 is at the discharge station of the machine. The mold must, therefore, be open at that time.

The discharge cam 28 is provided with an outwardly inclined end portion 280 (Fig. 2) which is spaced from the adjacent end of the cam 29 to provide a passage therebetween for the'follower. Therefore, when the follower leaves the cam 29, it will engage this outwardly extending flange 28 and the lower end of the lever 25 will be moved inwardly as the follower travels toward the main portion of the cam 28, and the outer section of the mold will, therefore, be moved outwardly to the open position as illustrated in Figs. 1 and 2.

The closing cam 29 is provided with an inwardly inclined portion 29a adjacent the end of the cam 28, and, therefore, when the follower leaves the cam 28, it will engage thisinturned portion and move the follower outwardly onto the outer surface of the cam 29. This operation will move the outer section of the mold inwardly to the position shown at the left of the drawings (Figs. 1 and 2) to thereby snugly close the mold. The cross bar 22 of the mold operating loop is .chine.

sufficiently resilient to enable the mold to be I closed and clamped with considerable pressure and at the same time allow for any mechanical inaccuracies in the mechanism.

The molds are preferably open only a suflicient length of time todischarge the grid, and an in- .clined track or chute 30 is positioned at the'diseharge station and underneath the path of the- 7 cross bar 32, and springs 34 are mountedonthe ejectorpins-tc normally retain the cros r 32 against the'heads of adjustable stop-b engage and move the ejector bar 32 and-pins 3| Push rods 35 are secured to the cross bar- 22 of the mold opening bail l1, and these push rods"; .pression chambers of suflicient size and distri-' Figs. 3 and 4 illustrate the grid segregating or stacking mechanism which comprises a rotatable table 4| pivoted at 42 on any suitable support and provided with a sprocket 43 secured to the table and connected to the drive shaft ,1 by means of a chain 44 and a suitable sprocket 45 I on the drive shaft. The table 4| is positioned adjacent the end of the chute so that the dis-- charged grids will .be delivered to the table therefrom, and is provided with a plurality of assembling or sorting stations corresponding innumber to the number of molds used on the maused, and therefore there are eight assembling stations on the table 4|, as shown in Fig; 4. The;

transmission between the drive shaft and the assembling table is of such ratio that all of the grids from a single moldare assembled in a group 7 or stack at the same-station on the assembling table. By this means, if any mold is defective. all defective grids therefrom will beassembled at one station. Also it will immediately be apparent that the corresponding mold is the defective 7 Furthermore, defective grids fromany single mold will not be mixed with perfect grids one.

from the other molds and may readily be found and disposed of. Also if a mold is found to produring the outward mold opening movement of the loop. This causes the ejector pins to loosen the grid so that it drops downwardly ontothe track 30, whereby it is directed to the group assembling table.

. It will be apparent that, by the use of a suit able driving transmission, the machine may be charge station, the metal is sufficiently hardened so that the grid may be ejected by the mechanism just described.

In moldingbattery grids,'it is desirable that an associated mold. By this means the molds the mold should be retained at a predetermined same mold and may be separated after being cast duce defective grids, it is not necessary to stop" V the machine until the end of the run, as -the de-.

fective molds will be segregated from-the perfect ones, or, if desired, the defective mold need notbepoured.

' As previously stated, for the successful operation of an automatic machine of this type that the molds should be so constructed that perfect grids may be produced such a manner that they may easily be ejected therefrom.- It has beenfound that this ishbest accomplished without the use of the usual vent holes or air passages and by the use of combution with respect to the strand'cavities that the back pressure of the gases is just sufficient to permit complete filling of the mold without forming fins on the strands. Molds suitable for this purpose are disclosed in Figs. 6 to 13, ill-f clusive. Both sections of the mold are-substantially. identical in so, far as the mold cavities are concerned. In some cases a flat-face mold is desired, that is, wherein the parting line is in aslngleiplane; This type of mold is illustrated in Figs. 6, 8, and 9. In othercases it is desirable in Figs. 10 to 13, inclusive.

In the embodiment shown in" Figs. 6, 8, and 9,

a portion of a mold section i411 is illustrated and. comprises a mold cavity 46 which provides a mar ginal casting groove 41, horizontal rib grooves 48, and intersecting vertical strand grooves 49. Terminal lug cavities 410. are also provided. v

- Fig. 7 is a diagrammatic elevation of a double grid produced by this type of mold and after the grid has been trimmed, and illustrates two integral grids 50 and 5| which are cast in the and trimmed to provide two smaller grids. The

transverse rib grooves 48 are larger than the strand grooves and are of subsfintially thesame depth as the marginal casting grooves 41. The

vertical strand grooves 49, however, are much smaller and are preferably deeper inone side may be retained at any required temperature. b

In the present instance, eight molds are i it is extremely important of-the mold than in the other to provide ofi'set strands in the manner shown in Fig. 8 so that a deep groove 49a. is in one mold section and the -opposing shallow groove 49b is in the opposite section. This provides staggered strands in a fiat-faced mold.

In Figs. 8 and 9 the two mold sections lla'and Mb are shown clamped together in their proper .strand grooves 49 and the transverse reinforcing rib grooves 48. These compression grooves 52 are preferably provided in each mold section, as illustrated in Figs. 8 and 9, and are preferably substantially of the shape'illustrated. It will be apparent, however, that thegrooves may be of any convenient shape and in only one mold section if desired, the only requirement being that they should be of sufiicient size and so related to the strand grooves as to enable a proper gas compression to provide for completely filling the mold without fins. The mold is provided with an inlet opening 53 and with gate grooves 54 to facilitate the introduction of molten metal.

' A very desirable form of grid is provided with so-called offset or staggered strands. This is important where it is desired to cast lighter strands, as it is necessary that the strands should be fiush with the sides of the casting. A mold for producing this construction is illustrated in Figs. -10'to 13, inclusive. Fig. 10 illustrates a portion of a mold llc having a marginal casting groove 55, horizontal reinforcing rib grooves 56, and vertical strand grooves 51. This type ofmold is provided with a corrugated face forming a zigzag parting line as shown. at 58' (Fig. 11). This is accomplished by forming each mold section by milling or otherwise in the direction of the strands to-form the corrugated parting line and the strand grooves, 51, complementary grooves 51 being formed in each mold section. Compression chambers in the form of elongated grooves 58 are then formed, one groove in each facet of the mold between each pair of strands. These chambers are preferably angular in cross section, as illustrated in Fig. 11, as this shape provides for convenient milling without undercutting. The compression grooves 58 are preferably in only one section of the mold. However, it will be apparent that complementary grooves may be cut in both sections if desired, the only requirement being that they shouldbe of sumcient size to allow for the proper amount of gas compressionto enable the mold to fill without forming excessive fins in the same manner as in the fiat-faced mold previously described.

The use of compression chambers instead of vents enablescontinuous operation of the machine in quantity production, as substantially all.

of the grids are perfectly molded, and it is only the grid, and it is desirable that a reinforcing fin be provided on the bottom edge of the grid for that purpose.

In the embodiment last described, the cutter which forms the corrugated parting line in the mold continues the out beyond the bottom of the grid cavity as shown at 59. These extended corrugations terminate in a marginal slot 60, which latter forms a horizontal reinforcing rib on the fin formed by the extended corrugations 59. A very light additional out is taken on the terminal corrugations 59 so that a very thin corrugated fin is formed as shown in Figs. 12 and 13, and, as this fin terminates in the horizontal table. Therefore, this fin provides a rigid element for handling the grid during the trimming operation and provides more area for chilling the fin and for venting during pouring, which is desirable as the heavy border portion usually fills first and air is trapped in the center portions. This reinforcement is accomplished without any material waste of metal over the usual methods. I The two mold sections I4 and I6 form what may aptly be termed die plates, and these die plates are preferably formed with complemental mold cavities. The compression grooves in either embodiment shown may be in only one die plate or, if desired, complemental grooves may be formed so that'each pair of grooves forms a single compression chamber of sufiicient size and relationship to the adjacent casting grooves to perform the required function. I

Fig. 14 is wat face view of the upper portion of the drag die plate which co-operates with the complemental cope plate. The present invention is adapted for continuous operation whereby, if desired, the molds maybe continuously moved past a fixed filling station, at which station a predetermined amount of molten metal is dropped into the inlet or screw opening 53 when the mold is moving in the direction of the mold opening, the movement of the mold tends ,to cause the metal to overflow at the rear of the mold opening. With a mold construction such cavity is provided. This is accomplished by very infrequently necessary to stop the machine means of transverse baffles 61 which are formed bycomplemental ribs or partitions in the sprue openings of the die plates with their sharp uppersufiiciently above the cavity to provide a passage 53 under each baflie to enable fiow of the metal grids from each mold from the grids of the other thereunder and provide a uniform distribution of the metal to themold cavity. The advanc- 4 ing end of the mold cavity is preferably angularly inclined forwardly as shown at 64, while the rear wall 65 is more nearly vertical to prevent overflow of any of the molten metal from the space between this end wall and the adjacent balile 6|. J

As previously stated, terminal lug cavities 61a are provided in the complemental sections of the mold, and it is desirable that at least the outer portions of these lugs be free of fins and thatthe edges be clean-cut and accurate so that the lugs on the casting may be used for locating the casting in a trimming machine or any suitable grid handling device. In order to accomplish this, one of the die plates, preferably the drag plate I4, is provided with a plug .66 slidably mounted therein and having a cavity 61 in the face thereof forming a part of the lug cavity of the mold. The plug or movable mold section 66 is slidably mountedin an. opening 68 in the die plate andis provided wtih rearwardly extending guide pins 69 slidably mounted in complementary guide holes, thus preventing any rotary movement of the plug 66 while'permitting axial movement thereof. A stop bolt 10 is threaded into the plug 66 from the rear of the die plate, as illustrated, and a spring II tends to move the plugfoutwardly whenever the mold is open, the outward movement being limited by the head of the bolt 10. It will be .apparent that, when the mold is closed, the outer surface or embodiments disclosed herein, since modifications may be made, and it is contemplated,

' therefore, by the appended claims to cover any such modifications as fall within the true spirit and scope of this invention.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is:

- 1. In an automatic grid molding machine of the character described, the combination with molds and to stack the grids oheach segregated group one on top of the other.

4. An automatic grid molding machine comprising a rotatable support having a plurality of radially disposed molds thereon for consecutive movement past a filling station and a discharge station by rotation of said support, means for ejecting cast grids from successive molds. at said discharge station, a rotatabl grid segregating table, means for directing the discharged grids onto said table, and means for moving said table in synchronism with the movement of said molds so that the grids from each moldvwill be in a segregated group on said table.

5. Inan automatic grid molding machine, a mold comprising a fixed drag and a movable cope, elongated leader pins rigidly supported on said drag, said cope being slidablysupported on said leader pins for movement to and from said drag and freely removable from said machine by outward sliding movement on said pins, a transmission for intermittently sliding said cope on said leader pins, said transmission comprising an intermittently oscillatable lever, and a link pivoted on said lever and having its free end engaged in an upwardly facing notch in said removable cope portion so that said cope may be moved outwardly on said leader pins beyond the normal outward limit of its movement or completely removed from said machine by raising said link out of said notch.

6. An automatic molding machine comprising a supporting frame, a rotatable table pivotally mounted on said frame, means for rotating said table, a plurality of radially positioned vertical molds mounted on said table, each comprising an outwardly facing drag section, outwardly extending leader pins on said drag section, a cope section slidably mounted on saidleader pins and freely removable from said machine by outward movement 'on said pins, outwardly extending I brackets on said cope section and having upwardly facing notches therein, an upwardly extending lever pivoted on said table at the rear of said mold and having a cam follower on its lower end for engagement with a fixed cam on said frame for intermittently operating said lever to ward and from said mold, a loop-like link pivoted on the upper end of said lever and extending around said mold with its outer span releasably means for successively ejecting grids from a plurality of molds at a single discharge station, of movable means synchronized with said ejecting means to receive and segregate the grids ejected from each mold from the grids of all the other molds.

2. An automatic grid molding machine comprising a plurality of sectional molds adapted to be closed for pouring and'opened for discharge of a grid therefrom, means for moving consecutive closed molds past a filling station, means for successively opening said molds at a discharge station, -and movable means synchronized with the movement of said molds to segregate the grids from each mold from the gridsof the other molds. I

3. automatic grid molding machine comprising a pluralityof sectional molds adapted to be closed for pouring and opened for discharge of a grid therefrom, means for moving consecutive closed molds past a filling station, means for successively opening said molds at a discharge station, and movable means synchronized with engaged in said notches for movement of said cope with said'lever, said cope being freely removable from said guide rods by raising said link upwardly out of said notches.

"7. In a grid molding machine, a mold comprising a fixed drag, a, movable cope, elongated leader pins fixed in one of said mold elements and in guiding relation to the other mold element, a transmission for intermittently recipro-' open, said latch being adjustable to enable manual movement of said cope a limited greater distance from said drag to enable inspection or spraying and the like of the mold faces and being further completely releasable from said cope toenable'free removal of said cope from said machine by outward movement parallel with said leader pins. I the movement of said molds to segregate the 8. The combination with a plurality of n molds, and means for successively discharging grids from said molds, of a rotatable grid segregating support, said support comprising succesfor intermittently reciprocating said cope, said transmission including a latch releasably engaging said cope for movement thereof a limited distance from and to said drag, said distance being suillcient' to enable the discharge of a casting from said mold and being limited to prevent chilling oi the mold when open, said latch being adjustable to enable manual movement of said cope a limited greater distance from said drag to enable inspection or spraying and the like of the mold faces and being further completely releasable from said cope to enable tree removal of said cope from said machine by outward movement parallel with said guides.

HERBERT C. WINKEL.

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