US1913945A - Turret casting machine - Google Patents

Description

June 1933- A. w. MORRIS ET AL TURRET CASTING MACHINE Filed May 6. 1931 I5 Sheets-Sheet 1 JNVENTOR. Al BERT W000 Mom/a A TTORNEYS.

Jim/15m: WHHER/LL, JR,

June 13, 1933. w MORRIS ET AL 1,913,945

TURRET CASTING MACHINE Filed May 6, 1931 3 Sheets-Sheet 2 INVENTOR. 11mm r W000 Mom/5 AND Y JZiMt/EL PRICE Mfr/IE LL,J

A TTORNEYS.

June 13, 1933. A. w. MORRIS ET AL 1,913,945

TURRET CASTING MACHINE Filed May 6, 1951 s Sheets-Sheet s INVENTOR. ALBERTMM Mam/5 JAM/EL BQ/OE Wen/ER/L J/e.

7/ A TTORNEYS.

l Patented June 13, 1933 UNITED STATES PATENT OFFICE ALBERT WOOD MORRIS, OF DREXEL HILL, ANT) SAMUEL PRICE WETHERILL, JR, OF HAVEBFORD, PENNSYLVANIA, ASSIGNORS TO WETHERILL-MORRIS ENGINEERING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF DELAWARE TURRET CASTING MAC' HINE Application filed ma 6, 1931. Serial No. 535,344.

This invention relates to a metal casting machine or apparatus. It is an improvementin what we will refer to as turret casting machines. In such mach nes a series of permanent in lds are carried by a turret past a filling station, a mold ejecting station, a mold cleaning or conditioning station (for example, a station to smoke the molds), a core inserting station, and any other stations that are desired. A machine of this general type is shown in applicant Morris prior Patent No. 1,239,808 of September 11, 1917.

We desire in the present invention to provide an improved means and mode of operation for manipulating the molds on the turret, for successively charging the molds on the turret with metal, and for coordinat; ing and timing the casting operations while retaining all the general advantages of a turret cast ng machine. In some effects these improvements give a new and useful machine operation, but some of them give better casting results which are more important. \Ve will describe the invention in connection with the accompanying drawings as an illustrative embodiment.

In the drawings,

Fig. 1 is a side elevation of our casting machine with the left-hand side cut away so as to permit a larger scale, and parts removed to make the drawings clearer;

Fig. 1a is a diagrammatic view of a mechanical motion used;

Fig. 2 is a plan view of a segment of-the machine as shown in Fig. 1.

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2, but with the assumption that a mold is at the filling station for the mold charging ladle to operate upon; and

Fig. 4 is a diagrammatic view of electrical control means for timing parts of the machine operation.

It will be clear from Fig. 1 that the machine shown is of very large size and adapted -to carry molds for both small and very large castings. A base frame 5 provides a central turntable support for the turret or table plate 8. The turning movement of the table is slow and the latter may be supported for rotation on a bearing plate carried by the base 5 with an annular oil well around the plate, all shown dotted at the upper part of the base. A part of hub 7 of plate 8 is shown in section and on this hub is a. ring gear 1 which meshes with a gear 2, one-half the size of gear 1. Gear 2 is operated intermittently by a four-slot star Geneva gear movement which we have indicated generally by 3. and its drive pin by 4. The motor m drives the Geneva movement through a reduction gear as indicated. The drive mechanism is such that ring gear 1 is driven intermittently by the constantly rotating motor m and so as to make eight distinct stops of suitable duration in each revolution. The number of stops corresponds with the number of molds on the turret. We have shown in Fig. 1a a diagram of a four-slot star Geneva movement of conventional type. The stop wheel 3 is such as would be on the shaft of gear 2, and keeper part 3 with drive pin 4 is such as would be carried by the shaft of the gear reduction means shown above in Fig. 1. Two revolutions of gear 2 rotate gear 1 a single revolution. And so with four stops for gear 2 there will be eight for gear 1 in each revolution. This kind of mechanical motion for intermittent angular movements is so well known that its detailed description seems unnecessary. Figs. 1 and 1a give the specific way of adapting it to our purpose and will be readily understood by a man skilled in the art of machinery who knows that eight stops are desired in each rotation of turret 8.

Around the periphery of the turret we have indicated (in Fig. 2) slots or openings 11 extending radially. A vertical supporting plate 12 is bridged across each of these openings to hold the stationary half of a mold 9. We have shown only one of the molds in place over one of the openings, but it is to be with respect to the stationary mold half. Each of the eight molds on the turret is supplied with a power cylinder arranged like the one shown in Fig. 2. I

At the top of each cylinder 10 is a valve box 17 and a rack and pinion 18 and 19 (Fig. 1) to operate the valve in the box for admitting and exhausting pressure fluid from pipe 20. The rack 18 is spring-pressed against a cam 40. The arrangement is such that the control valve is operated to apply power in the cylinder 10 to close the mold, hold it closed and then open it, as will be referred to later.

Extending vertically from the frame support 5 is a central column 6 to which the cam is secured (see Fig. 1). Above cam 40 a circular manifold 21 is mounted for rotation on the column. A pipe 20 from each of the eight power cylinders 10 is attached for connection with a power source (air pressure) through the manifold 21. The latter may be supplied by a pipe running axially of column 6 and then radially to the common chamber (shown dotted) in manifold 21. As pipes 20 rotate with turret 8, manifold 21 rotates around column 6, being suitably mounted and packed on said column for this purpose.

The filling station is indicated at line 3-3, Fig. 2, and the parts in position for the mold charging operation are shown in section in Fig. 3. With the closed mold' 9 brought to position by the turret, a power cylinder 71 .operates piston rod 31 to elevate charging ladle 34 for nozzle pipe 35 to register under pressure with mold gate 36. Then fluid pressure is admitted through pipe 32 against baffle 33 to act on the molten liquid level and drive the metal vertically through pipe 35 to fill the mold 9 quickly. The gate 36 has a restricted portion which will cause quick freezing of a stopper portion in the mold gate. When the charging pressure is exhausted through pipe 32, most of the metal in the gate 36 below the restricted portion drops back down pipe 35 (which avoids large sprues on the castings), piston 31 is lowered by exhausting cylinder 71 and the turret carries the filled mold away and brings another mold to the filling station.

As the molds are intermittently arriving at the filling station as the turret is rotated, at great deal of hot metal is necessary to supply them in the continued operation of the machine. It is not feasible to melt the large amount of metal desired at the machine or as part of the machine operation in the way we have shown By arranging the charging ladle 34 sq that it overlaps the edge of turret 8 we can provide a hinged cover which can be quickly opened. A flexible portion of the air pressure supply pipe 32 and its bafiie is carried by the cover so that when the cover is opened there is a safe assurance that the air pressure cannot be applied to the hot metal. At desired intervals this cover 45 is opened and ladle 34 supplied with hot metal by a ladle transport from a furnace operated according to foundry practice and generally in dependent of the machine operation. This supply by workmen is frequent enough to keep the metal in ladle 34 hot enough for the mold charging operation.

Our mold charging operation is an important feature of the invention. We are aware that charging ladles for filling a mold by bottom pouring under pressure are known. Such a ladle operation generally is shown in the prior Patent No. 1,747,728, granted to us on February 18, 1930, in which a special type of casting machine is disclosed. But so far as we know the mold charging operations for a turret type casting machine have never been coordinated with the advantages of a charging ladle such as we have disclosed in the present invention. It has been customary in operating turret machines having the capacity for large casting molds, to fill the latter by the labor of a workman who is sta tioned with a hand ladle to fill the molds from the top as they go by his station. Our improvement is not in the mere elimination of this worklnans function. What we accomplish. is something more. It is to have one charging ladle fill all the molds on a turret machine under the right conditions to get better quality castings while retaining the advantages of the turret machine. This is accomplished in the illustrative embodiment by filling the successive molds through a bottom pouring gate (and from the metal below the level of that in the charging ladle to avoid dross and impurities) so as to keep the metal from breaking its stream (as often occurs in top pouring with large casting work) and to keep all the metal in motion until the mold is filled. And this is accomplished by the one charging ladle operating on successive molds while the others in the machine are stationed about for the desirable work to be done apart from the filling operation.

These considerations are. of exceptional importance in turret machines for this reason. The turret machines are adapted to make very large castings in permanent molds and castings which have usually been made in sand molds. When these large castings are poured from the top by gravity, as they usually are, the permanent molds (and the permanent cores frequently used) cause a rapid setting of the metal. Sometimes the bottom of the casting will freeze before the pouring is finished. Sometimes the metal will shrink too much on the cores before the rest of the casting is cool enough to make it feasible to pull the cores. Sometimes the metal near the bottom of the casting sets so far ahead of the rest of the metal that the casting has severe and detrimental strains set up in it before the mold can be opened. This all tends to poor quality castings. It is frequently desired to heat treat the castings to improve their quality but if the casting operation has been carried on in a haphazard manner without giving its steps order and characteristics determined by metallurgical considerations, the castings fail to respond as desired to the heat treatment. We have conceived that these difficulties in the casting steps of a turret' machine can be practically eliminated by arranging the mold charging operation at the filling station as we have disclosed it. And of course the work is facilitated by making our disclosed arrangement.

There are castings which need to have their cores pulled within such a close range 0 time after the metal has set on the cores that a difference of one second in doing the work will make the difference between a good and poor casting. Such castings cannot ordinarily be made on a turret machine in permanent molds. The old way of operating such machines does not give a. uniform starting point in time by which any critical operation at stations beyond the filling station can be accurately determined. They can now be determined at any of the turret stations by the fact, that in our improved machine the permanent molds leave the filling station filled with metal that has all been kept in motion until the mold was filled and started off to the other stations at a more uniform cooling rate. This proper start for uniform cooling is figured from the exact time of completing the filling operation and the time between the filling step and the next critical step is made uniform with the filling step for each mold. This exactness in the turret machine operation would not be possible from operation in the desired any automatic gravity filling of the molds by automatic pouring. If the latter were used in a turret machine it would result in merely eliminating the work of the usual hand pourer. But our automatic type of mold filling in the turret machine goes beyond the mere elimination of hand work.

Following these considerations, it will be seen that the characteristics of our pouring association with the turret machine are of particular-importance. The bottom pouring operation substantially as shown is the one we prefer and which we have claimed specifically in combination.

- But we have improved the operation of a turret casting machine in the feature of its mold filling op ation in a way which can be accomplishec broadly by other specific apparatus than the one shown and with many of its advantages. If we consider Fig. 3, it will be apparent that the charging ladle could be shifted to the right, the nozzle 35 could be extended vertically with a goose neck top so as to contact with a top opening of the mold. In such a case the cylinder 71 would need to be operated 'to raise the charging ladle to break connection with the mold and lower it to make connection. The liquid metal would be forced into the mold by the air pressure through pipe 32 the same as in bottom ouring. Or instead of a top or bottom liiling openin for the mold a side opening could be used. n the latter case the charging ladle would be mounted to reciprocate horizontally instead of vertically to make and break the connections with successive molds with side filling openings on the turret. In all of these cases,T-bottom, top, or side pouring into the mold,-as long as the level of the molten metal (when the air pressure from pipe 32 is off) remains below the actual mold orifice,

mold in timed relation to the turret operation can be carried out. The metal may be raised through the ladle nozzle arran ed either vertically as shown or at an angle. bottom pouring has the advantage over the others in that it provides a simple way to keep the hot metal all in motion as it is fillllxllg the mold cavity and until it is filled.

ith top pouring this might be done also but it would require special mold filling passages and would not be so simple as that shown. With a side opening in the mold for filling, such opening could be on a level with the bottom part of the mold cavity and this would keep the metal in motion until filling was completed. But it would not appear to be quite so desirable as the bottom pouring.

With such possibilities in mind, we have claimed in addition to the specific form of the bottom pouring arrangement, the structural arrangement in somewhat broader language to take in the idea of the obvious variations that might be made in our specific form to get some important part of the advantages in the improved combination of a pressure charging ladlecoordinated with the turret machine for the latter to produce better quality castings.

Another feature of invention on the turret machine we have disclosed, is in the mold opening and closing devices, including the way of holding the molds closed by the power cylinders. Heretofore turret molds have been manipulated by mechanical means such as cam rods, etc. These have the disadvantage of changing ing unyielding and not under all conditions being capable of doing the desired work. By providing a series of air cylinders, with movable mold parts, on the piston rods we get these advantages. The mold is closed with a continued follow-up pressure constantly available while the mold should be closed, a simple yielding pressure for protecting the mold from unbearable strains, a self-adjusting mold closure to hold the molds together even when warped and a pressure holding difierent mold positions their operation by wear, be-' f the principle of quick pressure filling of the at the various turret stations, or between such stations. This latter feature is of considerable importance when it is desirable to partially open the mold to pull cores or for any of a great variety of other reasons in casting work. The turret machine is fundamentally a more flexible type of casting machine than other types and when provided with theair cylinders for rotation with the molds to manipulate them in various ways around the turret the flexibility of the machine is enormously increased. It is now no longer necessary to adjust or change or substitute all the mechanical contrivances on the turret to change the mold manipulating operations. It is only necessary to change the admission or the exhaust of the air cylinders as they arrive at one or another point in the turrets rotation. And this can be done in one most simple manner by the mere peripheral contour of the stationary cam 40.

For the control of the machine, we have already described the mechanical movement for driving the turret 8 through a cycle of eight steps and eight stops. Obviously the number of stations, speed and time of dwell eight steps and eight stops. Obviouslythe work. The stationary cam 40 deternnnes the admission and exhaust of air to each power cylinder 10 at appropriate points in the circle of each molds movement with the turret. lVe have not'attempted to show all such movements as may be desired by an indicated plotting of the cam 40. The desirable changes in the contour of cam 40 must obviously be made according to what particular mold movements are desired. These will all be understood by the man skilled in the art.

It is desirable to time the operation of power cylinder 71 to lift and lower the charging ladle to correspond with the predetermined timed arrival of successive molds 9 at the filling station indicated in Fig. 3. And the pressure from pipe 32 shouldibe admitted and exhausted in timed relation to the desired bottom pouring operation. This automatic timing requires a control device for cylinder 71 and pipe 32. We have jointly invented an automatic timing device for casting operations shown in Patent No. 1,816,491, dated July 28, 1931, which can be used for our present purpose of controlling the time of the named operations.

\Ve have shown herein in diagrammatic form (Fig. 4) a lneans to control said operations. Two timing switches with contacts 89 and'98 are on a common shaft which is geared to shaft 91 so as to turn constantly, and to make one revolution for each revolution of the turret. The terminal switch 90 in circuit 88 is arranged to be closed by contacts 89. A solenoid 87 will be energized intermittently and eight times for each complete turn of the turret. Each time the solenoid will operate the valve stem 100 extending from valve box 95 to admit air pressure to cylinder 71 as indicated. The spring indicated will return the valve stem to exhaust position as the solenoidis deenergized. In proper timed relation to this intermittent operation of power cylinder 71, the contacts 98 close terminal switch 82, energize solenoid 84 to operate tliestein of the valve in box 85 to admit air pressure to pipe 32 and elevate the metal through the bottom pouring nozzle. The spring 86 will return the valve stem so as to exhaust the pipe 32 when contact 98 leaves terminal 82 of circuit 83. As indicated, the contacts 98 are shorter than contacts 89 so that the air pressure will be applied and released in the charging ladle 34 while the ladle is held in pouring relation to mold 9.

The turret machine we have described can be used either with large molds having multiple interconnected cavities for making small castings. Or it can be used with very large molds to make single castings of larger size than is commonly made in permanent molds. It is capable of making castings a large as pipe sections and castings of a character having a much longer dimension in one direction (height) than in the other, of which pipe sections are an example.

Having described our invention, what we claim is:

1. A casting machine having a horizontal turret with permanent molds thereon, spaced around adjacent the turret periphery, an opening in the turret under each mold to charge and discharge the same, means to suecessively position the molds above charging and discharging stations, a mold charging device at the charging station comprising a metal st rage ladle arranged to hold molten metal ingvsuflicient quantity to avoid the necessity r extraneously supplied heat between charging operations and means to cause registration between a bottom inlet of each mold and the charging device for abottom pouring mold filling operation, said means including an elevating device to move the charging device into and out of bottom pouring relation to each mold when at the charging station, power means for rotating the turret, for operating said elevating device, and for opening and closing said molds, and means operable by the turning of the turret to time the application of power to open and close the molds.

2. A casting machine comprising a rotatable table or support, permanent molds arranged around the outer edge of the table, a mold opening and closing device for each mold, power means to rotate the table and operate each of said devices in definite timed relation, a mold charging ladle having means for pressure registration with said molds when they are turned to a filling station and having separate means spaced from said mold registering part to fill' the ladle, said ladle havin its mold re istering part underlying the e go of said ta 1e and its said separate filling means beyond the edge of said table, 5 means for lifting the charging ladle into registration with a mold positioned above the same and means for applying pressure to the contents of the charging ladle to lift the metal therein to fill the mold through a bottom opening, said ladle having a capacity for filling many successive molds before it is necessary to recharge the ladle through its filling means.

3. A casting machine comprising a rotatable table, a series of permanent molds supported in spaced relation around the outer edge of the table, said molds havin a bottom gate for pressure pouring, a mol charging ladle having a support independently of the table and a pressure registration nozzle for contact with such a gate, said ladle having means to force metal vertically through said nozzle under pressure against all the metal in the ladle, said ladle also having a metal charging gate separate from said nozzle and located beyond the edge of said table, means to rotate the table to successively bring said molds into position for registration with said nozzle and means to lift said nozzle into registration position with said molds, one by one, as they are brought into position, said ladle being arranged to operate apart from furnace operations so as to charge the molds at a position remote from the necessary metal melting operations. I

4. A casting machine comprising a rotatable table, a series of permanent molds mounted around the outer edge of the table, said molds having a bottom gate for pressure pouring, power means to rotate the table in timed relation and bring said molds successively to a filling station, a charging ladle at said station having a pressure registration nozzle for connection with such a mold gate at the station, said ladle havirig'power means operable on all the metal in said ladle to force metal vertically through the nozzle and into the mold under pressure, and timed controlled means to cause registration of said ladle with successive molds as they arrive at said station and to apply said power means to force metal into such molds, said apparatus being operable with heat supplied solely by 55 the molten metal placed in the ladle and said ladle having a metal charging opening apart from its nozzle, said ladle being of sufiicient capacity for many continued successive mold filling operations without being recharged through said opening.

5. A casting machine comprising a rotatable table or support, permanent molds arranged around the outer edge of the table, a mold opening and closing device for each mold, power means to rotate the table and operate each of said devices in definite timed relation, a mold charging. ladle having unobstructed upwardly extendin outlet means for pressure registration wit said molds when they are turned to a filling station, said ladle being located adjacent .the edge of the table and arranged to hold molten metal normally below the level of the mold filling orifices, means for moving the charging ladle in-to registration with successive molds at the filling station, and means for applying pressure to the whole contents of the charging ladle to force it toward the upwardly extending outlet and into a mold whenever the charging ladle makes registration contact therewith, said ladlebeing of suflicient capacity apart from all furnace operations to hold and supply metal for continued successive mold filling operations, said ladle having a hot metal charging opening with a cover therefor located apart from its outlet means whereby the machine may operate without a furnace means incorporated there- 1n.

6. A casting apparatus comprising a power operated turret with permanent molds mounted in spaced relation adjacent its periphery so as to successively pass operating stations, a power cylinder on the turret for each mold, means to control the operation of the power cylinders so that they may be successively opened and closed by the cylinder at appropriate stations, said control means being operable by the turning of the turret, a mold charging ladle of suflicient capacity for filling many successive molds without replenishment of or reheating the metal in the ladle between mold filling operations, and power means to place all the molten metal of said ladle in direct pressure filling relation with each mold as the latter arrives at one of said stations, said apparatus being arranged to be supplied with its metal pouring heat solely by hot metal from an outside source supplied to said ladle, said ladle being constructed to retain the required heat within T the time that its contents can be used up in the operation of the ap aratus as described.

In testimony whereo we have aifixed our signatures. 11

ALBERT WOOD MORRIS. SAMUEL PRICE WETHERILL, JR.

6 (CER'IIRIFIIGATE (NF GQRRIEC'EINDN.

Patent No,- LQB,

Antoni Wfiillll hltlRlS, El it.

it lo hereby certiiied that error appears in the printed specification of the above numbered patent requiring correction as lollows: Page 4, line27 and 28, atrilteout the words "eight steps and eight stops. Obviously the work" and insert instead "at dilierent stations will be made to fit the work"; and line W, tor "a" read "as"; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the ease in the Patent tiliiice.

Signed and sealed this 8th day of August, A. 1). i933.

hi. H. Moore.

(Seal) Acting Commissioner oi Patento

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