US2068835A - Foundry system - Google Patents

Description

Jan. 26, 1937. H. WURSTER 2,068,835

FOUNDRY SYSTEM Filed March 13, 1955 4 Sheets-Sheet l MOLD rRAMs-Fna CONVEYOR DEE] ASSEMBLM/ COOL //v JECf/O/V MOLD- MOLD MAk/A/q CONVEYOR L J 3nnentor SAND RE ruAW HEA/R YA. WuRs 715R:

Y attorney FOUNDRY SYSTEM Filed March 15, 1935 4-Sheets-Sheet 2 I n Eunentor fif/VR m. wups 75R (i ttorneg Jan. 26, 1937. H. A. WURSTER FOUNDRY SYSTEM Filed March 13, 1935 4 Sheets-Sheet 3 Snventor WURS 75/? TM (lt torneg HEA/QYA.

Jan. 26, 1937. A. WURSTER 2,068,335,

FOUNDRY SYSTEM a V attorney 45 wings, wherein:

Patented Jan. I 2 6, 1937 This invention relates broadly to founding and is particularly concerned with that phase of foundry work dealing with the production of parts-castings of different types on a volume 5 basis, or the production of an entire assembly of castings going to make up a complete machine or article regardless of whether or not volume production is contemplated.

The'present invention may be considered in 10 the nature of an improvement over that disclosed in my prior Patent No. 1,911,542, granted May 30, 1933, and includes among its objects those noted in said patent, with alternate types of, and which for certain installations may be considered 15 improved apparatus for carrying out such objects. In the present instance, th'e system is carried into and through the casting department and the cycle completed from thee/making and assembling of the molds to the removal of the castings and return of the sand to' the conditioning plant and the return of the flasks to the patterns or cope and drag plates at the start of the cycle.

A further important object of the present invention, in addition to the saving of time and laher and reduction of production costs,is to lighten the burden of the foundryman by eliminating heavy manual labor and rendering certain operations automatic so that he may devote more time to constructive work and thereby produce better 30 castings generally and be more content .and take a more active interest in his work.

Another object of the invention is to provide an improved founding system capable of being carried out by apparatus which in general may be obtained in the open market and adapted to the improved system without changing vital operatingparts-which have already demonstrated their practicability through actual usage, therea by eliminating costly experimentation and 40 changes in design which might otherwise vbe necessary. v

The oregoing, and other objects and advantages will become apparent in view of the follow- 1 g description taken in conjunction with the Figure 1 is a plan view, more or less diagrammatic, of" apparatus constructed and coordinated ina manner such as to render it capable of carryto the illustration in Figure-1;

FigureB is a view in side elevation of Figure 2 taken'about on the line 3-3 in the latter figure 55 and also including the sand-delivery apparatT;

Figure 3a is an enlarged sectional view taken along the line 3-4 of Figure 3; 2

Figure 4 is an enlarged sectional view taken. about on the line 4-4, Figure 2 and particularly showing one of the machines for the mold-mak-. 5 ingiconveyor;

Figure 4m 'is a view in side elevation of Figure Figure 5 is a view in side elevation of a portion, of the mold-transfer conveyor;

Figures 6 and 7 are, respectively, views in side and end elevation of automatic weight-handling or mold-clamping machines forming part of the apparatus, said viewsbeing taken about on the lines 66 and 1-1, Figure 1; and

Figure 8 is a -fragmentary view in side elevation of a'modifled type of mold-making mecha:

nism.

.The term mold-making is meant to cover the making of molds for both plain and cored .castings, or in other words, dry sand cores may be made in the same manner in which molds are made.

The entire lay-out is shown more or less diagrammatically in Figure l, and consists generally of a series of cordinated conveyors having mounted thereon conveying and molding machines which carry the parts going to make up the molds. The molding sand is conveyed to the v flasks in a particularly advantageous manner directly from the sand conditioning plant, the sand being automatically leveled,'packed and thereafter returned to the conditioning plant.

The apparatus and method which I have provided includes three conveyor systems, namely a mold making conveyor system, a mold transfer conveyor and a pouring conveyor system. The flrstof said systems comprises generally a series of mechanisms which automatically and successively operate to flll the mold flasks with loose 40 sand',.thereafter' jar and pack the loose sand around the pattern and raise the mold from the pattern. The second of said conveyor systems operates to transfer the molds from the first system'to the mold pouring conveyor system. The intermediate system, that'is, the mold transfer system and the first and third named systems overlap for a portion of their travel to permit the workmen operating the foundry assembly to pick up the mold parts from the making conveyor and arrange them on the pouring conveyor. The

pouring-conveyor system includes a station carrying a series of automatically raised and lowered weights which. function to secure the mold parts lnposition during the pouring. Subsequent to ,direction generally horizontal.

the pouring and the automatic removal of the weights referred to a considerable section of the pouring conveyor is utilized for cooling the castings.

Referring to the drawings and the steps of my method in the sequence in which they are carried out the letters A, B and C adjacent the mold making conveyor indicated diagrammatically in Figure 1 indicates stations where workmen arrange molding flasks and patterns upon a series of interconnected andages or machines which move continuously-in the oval orbit or path indicated. As the conveyor units with the mold flasks and patterns properly arranged thereon reach a point indicated at D, sand is discharged into the open top of the flasks. The molding sand is preferably conditioned at a sand conditioning plant at 5 adjacent the mold making conveyor and this plant may comprise an elevator G which elevates sand from a pit to a feeder 1 from which it falls upon a conveyor means 8 which transports the sand to an aerating and discharging assembly positioned above the flasks.

Since about 90% of the light casting work is known in the art as riddle work or work requiring a smooth finish, it is important that in a combined or automatic mold forming equipment such as I have provided that the sand will be positioned about the patterns in a manner to produce acceptable riddle work castings". Sand that is well conditioned by the known sand conditioning systems has a tendency to form lumps of balls while being transported from the sand conditioning device to the flasks. Such undesirable sand exists whenever the sand is transported on a belt, trough, hopper or the like. Such lumpy sand even though otherwise well conditioned and aerated will not produce acceptable riddle work castings.

To overcome the objections incident to transporting conditioning sand from a sand conditioner to the pattern I have provided a novel sand agitating or discharging device at the end of the conveyor 3. Referring particularly to Figures 3 and 3a the conveyor 8 is provided with an extension conveyor 8a which continues the movement of the sand from the conveyor 8 in a Sand plows l9 and we or analogous devices are placed above the conveyor extension 8a and are so arranged as to scrape the sand off of the conveyor extension 3a and direct it into the open chutes 9-911 and 91) arranged below the conveyor extension. The lower end of the chutes 9 and 9a are directed inwardly beneath the conveyor extension so as to discharge sand at the outer edges of the relatively large or wide pattern arrangement whereas the lower end of the chute 9b terminates substantially in the center of the pattern arrangement passing therebeneath and thus discharges sand into the central area of the patterns passing therebeneath. It will be appreciated that this arrangement provides that in the event relatively small flasks or small pattern arrangement are carried by the conveyor beneath the sand discharge that the chute 9b alone may be employed to fill the molding flask.

Whatever lumps or chunks of sand may have been formed during the transporting of the sand from the conditioning plant 6 to the discharge assembly are effectively broken up and completely aerated by the agitators or aerating devices I l disposed in the chutes 9-911 and 9b. As best shown in Figure 3a a motor Ha having a shaft lib is arranged generally parallel to the conveyor track 3!.

veyor and transverse shafts 0 are provided with a driving connection therewith such as a bevel gear or the like and said shafts llc extend laterally into the chutes 9, 9a and 9b. The agitators H secured to the shafts within the chutes are provided with plates which are curved and thus aid the force of gravity in directing the sand downwardly into the flask. It will be observed that this method of forcibly throwing aerated, perfectly conditioned sand against the patterns produces acceptable castings having a smooth finish and thus my method distinguishes over prior art methods wherein the sand is dropped or lowered into the mold flasks from a hopper.

The carriages or machines which travel steadily and continuously about the mold making conveyor path are indicated generally at I? and comprise a frame 52b provided with flanged wheels 520. which normally rest upon the con- A second set of flanged wheels .29 are provided to support the carriage l2 during the jarring or jogging of the sand subsequent to the filling of the flask. A short section of track 39 is provided adjacent the sand discharging station and is formed with sloping ends to guide the wheels 29 of the carriage I2 as they traverse this section of the conveyor path. This section of the conveyor path may be referred to as the jarring station and the track 36 is rereferred to as an anvil track inasmuch as the carriage i2 is provided with automatically operated mechanism to forcibly raise and lower the pattern table l3 to jar the sand in the flask 1.

During the movements of the conveyor which jar or jog the sand into position around the pattern considerable settling and compacting of the sand takes place. The fact that the track 38 and wheels 29 are elevated from the track 31 throughout this station prevents the transmission of the jarring or vibrating forces to the rest of the carriage or machines H2 in the conveyor system. To effect the raising and lowering of the assembly which produces the jarring referred to a cylinder 520 is mounted at the underside of the carriage or machine i2 and carries therein a piston lZd operatively connected to the pattern table IS. A conduit i l leads from the cylinder I20 to an inlet chamber i'la which is connected to a common flexible conduit l7 connecting all of the carriages or machines 9 2. The conduit i7 is connected as at H! to a flexible lead-in conduit l8 arranged at the center of the mold making conveyor systern.

As shown in Figures 2 and 3 a hose reel or the like 29 is mounted at a central point within the conveyor orbit and a flexible conduit it? carried thereby leads to a conduit header fitting l9 which is carried by the series of mold units on the conveyor, The reel attached end of the conduit is terminates at the rotational center of the reel 20 as is usual in such constructions.

Since the specific reel structure is but an element in the combination of my invention any suitable reel structure may be employed at this point and preferably reel structures carrying flexible conduits such as those disclosed in the patents to Ludwig No. 1,881,764 and Lea, No. 1,908,852 are employed to conduct the fluid pressure from the central point of the conveyor path to the header fitting l9 carried by the mold units. As will be observed by reference to the Lea and Ludwig patents and as is conventional in reel constructions of this type coil springs are arranged to tension the flexible conduit intermediate the reel and the object carrying the free otherwise lost from the flasks as they traverse end of the hose so as to rewind the conduit upon the reel. This construction becomes advantageous in connection with the molding apparatus of my invention in that the slack is kept out of the flexible conduit as the header fitting l9 moves from the major axis of the oval conveyor path to the minor axis thereof. The rewinding characteristics of the reel structure such as shown in Ludwig and Lea become unimportant where the conveyor path is circular or where other means are employed to control the flexible, conduit.

A spring pressed valve 2i is interposed between the air conduit H or fluid pressure inlet chamber Ila and while the carriage unit l2 traverses the jarring track section 30 a member 24 is brought into engagement with the valve 2| so as to admit air or fluid pressure to the conduit l4 and thus raise the pattern table l3: As the carriage units traverse the anvil track 30 and the bar 24 the pattern plate i3 is raised and lowered and following this station the conveyor units are brought beneath a bar 31 which functions to scrape off the sand which extends above the edge of the flask f. In this connection attention is directed to the-pins i3 carried by the pattern table l3 which extend into apertures I carried by the flask f and serve to retain the flask in position on the table throughout the filling, jarring, scraping, and tamping operations (Figure 3). The station where the scraping takes place. is indicated at F in Figure 1 and following the leveling or scraping action of the bar 31 the conveyor units pass beneath a tamping mechanism indicated at 38 which comprises a series of fluid actuated rammers or tamping plungers 38a.- The plungers 38a continuously reciprocate and the enlarged heads thereon serve to uniformly tamp and pack the sand into the flask as the flasks continuously move therebeneath.

Following the tamplng or packing station indicated in Figure 1 as at G the units pass beneath a leveling or strike-off device 39 which trowels or smooths the sand flush with the top of the flasks. Preferably the upper edges of the flasks fv are sloped downwardly as at 39b to facilitate the smooth troweling or ride-over movementof the device 39 which is. mounted to permit a limited vertical movement. After leaving the" flnal level-- ing or sand packing device 39 the units come to a vibrating station indicated in Figure 1 at I and defined by the bar 23 in Figure 2. As'the continuously raised and through rods i2i con-' nected therewith will move the flask I away from the pattern p in the manner illustrated in Figure- 3; The bar 26 having considerable extent along the conveyor path maintains the flasks in their raised position while they approach the .station'indicated at K at which station they are areprovided with a continuous sand pit therebeneath and the sand which is jarred, scraped or veyor. end 43 which is adapted to engage the wheels 43c and raise the weights'flb clear of the flasks f. To ensure a smooth lowering action and consaid stations drops into the sand pit 33. The lower wall of the sand pit 33 is provided with a conveyor belt 36, the upper end of which travels in a direction opposite to the travel of the conveyor units and functions to return the sand dropped into the pit to the sand conditioning apparatus 6.

Any suitable means for driving the conveyor unitsor machines i2 may be employed, for example, a continuous sprocket adapted to engage the axle shaft or the track wheels l2a could be provided and mounted at any convenient point adjacent the tracks 3|. Preferably the machines are connected in tandem and their travel is continuous throughout the path of the conveyor.

Referring now particularly to Figure 1, it will be noted that a mold or flask transfer conveyor generally indicated at 40 is mounted adjacent the mold-making conveyor and is timed with the latter. A preferred type of conveyor is shown in Figure 5 and comprises an overhead track 40a having suspended therefrom a series of bale hooks 40b through the, medium of hoist mechanism generally indicated at 400, the respective units being connected by a flexible chain or like member as at 40d, the bale hooks 40b having a universal suspension connection with the hoist mechanism 400. The flasks are provided with trunnions 41, so that an attendant may stand adjacent the, point of transfer and engage the hooks 40b over the trunnions 4|.

While the conveyor 40 is shown more or less in detail in Figure 5, it will be understood that this showing is simply to illustrate an operative mechanism and is not to be construed as alimitation on the combination of apparatus as aparts are matched and the flasks closed, it is generally necessary that they be held in clamped or weighted relation to prevent separation or displacementduring the pouring operation and subsequent cooling of the metal. In the present instance, this clamping operation is performed automatically by means such as that illustrated more or'less in detail in Figures 6 and 7 and shown-in plan at the right of Figure 1. This mechanism comprises a series of weights 43 each of which is carried by a support or holder 43a, the latter in turn being adjustably secured to a trunnion bracket arm 43b in which a wheel 430 is journaled. A stationary semi-circulan cam track 430' is installed at the one end of the conveyor 42, and the wheels 30 travel on these tracks during the time the weights 43 are in in- .operative position. A pedestal bracket 43d is mounted on a conveyor 43c, and the bracket arm 43b is pivotally connected to said. pedestal bracket. The conveyor 43e is continuous and may be operatively connected to, or driven in synchronism with the mold assembling and'pouring con- The track 430' is provided with a cam tact of the weights 43b with the flasks f, a shockabsorblng or retarding member 44 is preferably provided, note Figure .6, and may consist 01 a fluid cylinder having a plunger a mounted therein to which an arm 44b is connected, the latter in turn having a sliding pivotal connection with the arm 43b. The cylinder 44 is connected to the pedestal bracket 43d and may be provided with the usual by-pass ports common to devices of this type.

The flask weights 43 above described obviate the need for moldclamping devices and this renders my system more nearly automatic and better suited to high speed production. The need for mold weights, that is, weights to hold the sand in the flask compact during the pouring and setting period is obviated by the use of flask bars ,b as indicated in Figure 2. The strain put upon the mold while the metal is being poured therein is taken by the transverse flask bars Ib and since the massive flask weights 43 which I have provided eliminate the need for conventional mold clamp pins the foundry worker's time is not consumed fastening and unfastening a plurality of clamps or latches.

The operation of this mold clamping or weighting assembly is follows:

The track 430' constitutes part of a circle or the said track is discontinued adjacent the poursection 1: of the conveyor 32, so that when the units 43 reach a point in registration with the traveling flasks, they drop off of the end of said track and lower onto the top of the flasks.

During this time, the pouring operation is completed, the weights remaining on the flasks until the latter reach the cam end 43f, whereupon the weights are raised clear of the flasks.

The conveyor 42 extends to a point adjacent sand shake-out mechanism generally indicated at 45, and which mechanism is more or less diagrammatically illustrated since it may be of the conventional type obtainable in the open market.

The sand from the molds falls through a grating 46 and onto a return conveyor 41 which conveys the sand back to the conditioning plant 5.

Adjacent the shake-out mechanism and above the conveyor 41 is a gravity flask conveyor 48 which returns the empty flasks to a flask return conveyor 49, the latter being of substantially the same type as the conveyor 40 and operating in substantially the same manner.

The operation of the machine may, of course, be varied to suit conditions, but in general is as follows:

At A, one or more attendants clean the patterns and set chaplets; at B, an attendant places the drag flasks on the pattern plates; at C, the cope flask is placed on the pattern plates; the foregoing operations being manual and capable of being performed by unskilled labor.

At D, sand is directed into the conveyor through the hoppers 9, 8a or 92), the sand as it drops through the hopper or hoppers being subjected to the aerator l 5.

At E, the machines l2 pass the cam 24 (note Figure 2) and the valve 2i is depressed and air admitted to the jolt cylinder l2c, whereupon the jolting operation takes place automatically.

At F, the device 3'5 serves to rough plow or strike on" the surplus sand, after which the flasks pass beneath the rammer 38, this oper ation taking place at station G.

At H, the sand is leveled substantially flush with the top of the flask by the device 39.

At I, the cam 25 contacts the valve 22 and opens the line to the vibrator cylinder; and approximately at J, the stripper valve 23 is opened flasks being held in elevated position along the station K to give time for one or more attendants to transfer the molds to the conveyor Ml, the attendants simply engaging the bale hooks 40b over the trunnions 4| of the flasks, the actual transfer operation taking place about at L.

At M and M, the molds are matched and closed, or in the case of a core job, the core may be Isgt at M and the molds matched and closed a The pouring station is indicated at N, and just before reaching this station, the weights t3 are lowered onto the flask due to the fact that the wheels 43 have moved clear of the raised track 430'.

That section of the conveyor between the pouring station N and the station may be considered as the cooling section; and when the molds reach the station 0, an attendant transfers the flasks to the shake-out mechanism, from which point they are placed on the conveyor 38 and passed down to station P, where they are placed on the flask-return conveyor and re- "tilrned to the stations B and C, where they are placed over the pattern plates and the cycle repeated.

The patterns which are exposed at the left hand extremity of Figures 1 and 2 illustrate how varying types of castings may be made continuously and without interruption regardless of their size, shape or weight. In other words, a mixed job may be run as easily as a single or similar line of castings.

In Figure 8, a modified type of mold-making mechanism is shown which is particularly adapted for relatively small work where the parts to be handled manually are not overly heavy. In this instance, the flasks may be stripped manually. The conveying track is indicated at 56, the conveying machines at and the flasks at f. The machines 5! are preferably each provided with a depending bracket 52 carrying a bearing wheel 53 adapted to engage jarring cam members 5 3 formed on an anvil track 5%, thereby performing the jarring operation automatically. The installation in thisinstance is much simplified with respect to that shown in Figures 2 and 3. It will be obvious that certain of the apparatus shown in Figures 2 and 3 may be utilized in this modifled structure, notably the gravity feed of the sand. This combination, or a gravity feed with a mechanical jarring action, results in a much simplified arrangement; and in the case of certain types of shallow or light work, the jarring mechanism may be entirely dispensed with.

-It will be understood that certain changes in structure and design may be adopted within the scope of the invention as defined by the appended claims.

I claim: A

i. In a molding apparatus, a sand conditioning unit, a chute for discharging sand into a flask, means for constantly moving a series of flasks beneath said chute, a constantly moving conveyor interposed between said conditioning unit and said chute to transfer sand from said unit'to said chute, means within said chute to break up the lumps and balls of sand occasioned by movement along said conveyor and throw the agitated and aerated sand downwardly through said chute and directly against patterns in the molding flasks disposed therebeneath.

2. In a molding apparatus, a sand conditioning unit, a chute for discharging sand into a and the flasks raised clear of the patterns, the flask, a conveyor interposed between said conditioning unit and said chute to transfer and discharge sand into said chute, means within said chute to break up the lumps of sand occasioned by movement along said conveyor and throw the agitated and aerated sand downwardly through said chute and into the molding flasks disposed therein, said means comprising a shaft transversely arranged with respect to said chute provided with inclined blades and a motor to rotate said shaft.

3. In a molding apparatus having a series of interconnecting units. constantly traveling about a conveyor path, means to jar said units during a part of their travel comprising a fluid pressure cylinder carried by each of said units, a plunger therein operatively connected to a pattern and flask supporting table, means to admit fluid pressure to said cylinder comprising a flexible conduit leading from a fluid pressure supply to said units, a valve interposed between said flexible conduit and said cylinder conduit, means adranged adjacent said conveyor path and extending for a limited distance therealong to engage said valve to eiTect movement of the flask and pattern withrespect to said unit.

4. In a molding apparatus, a series of interconnected mold units arranged to' travel about a closed conveyor path, said units comprising a pattern table adapted to support a pattern and aflask, an air cylinder mounted on said unit beneath said pattern table, a piston therein and means operatively connected to said piston and said flask to effect a raising of said flask with respect to' said pattern table upon movement of the piston within the cylinder, a fluid pressure conduit leading from said cylinder to a valve mounted onsaid unit, a member fixed with respect to said conveyor adjacent the path thereof arranged to engage said valve means upon travel of said unit therealong, a flexible conduit connected to said valve means and leading therefrom to an air-supply whereby upon travel of said units about said conveyor path said valve is opened by'said member to admit air into said cylinder and the flask is raised with respect to said pattern and pattern table.

5. In a molding apparatus, a mold assembly and pouring conveyor comprising a series of interconnected flask supports arranged to be continuously moved about a closed conveyor path, complementary flasks arranged upon said supports, a pouring station along said conveyor path, a mold flask clamping device arranged'at said pouring station comprising a wheel having a series of weights pivotally mountedthereon and laterally projecting therefrom, said wheel timed to rotate in synchronism with said flask supports as said flask supports traverse said pouring station, means to raise said weights above the level of the flasks carried by said flask supports as they leave said pouring station and means to lower said weights upon said flasks to effect a clamping thereof at said pouring station.

6. In a molding apparatus, a conveyor comprising a series of interconnected flask supporting units, said conveyor having one portion of its path curved to provide a pouring station, a flask clamping mechanism arranged at said portion of said conveyor path comprising a wheel having a plurality of pivoted weights projecting laterally from the periphery thereof, the projection of said weights beyond the periphery of the wheel being suflicientto overhang molding flasks carried by said supports,-means toraise said weights above the plane of the top of the molding flasks as said flasks and weights leave said pouring station and g I means to lower said weights and eifectively clamp said flasks during the pouring thereof.

.7. In a mold assembly and pouring system, a conveyor having an elongated path with curved ends, a series of interconnected flask supporting units on said conveyor, a flask clamping wheel mounted at one end of said conveyor path, said wheel having an axis corresponding to the axis of the curved end of the conveyor path, a plurality of weights pivotally mounted on said wheel, said weights arranged to project beyond the periphery of said wheel and overhang the flask supporting units of said conveyor path throughout the curved end thereof, said wheel and said conveyor traveling in timed relation whereby each of said weights overhangs a complementary pair of flasks carried by said flask supporting units, means to maintain said weights in a raised position as the weights and flask approach each other, means to lower said weights when they have attained an overhanging relation with respect to said flasks to efiectively clamp said flasks and facilitate the pouring'thereof, means to raisesaid weights with respect to the flasks subsequent to said pouring said wheel and the curved portion of the conveyor path to a cooling section.

8. In a molding apparatus, a sand conducting unit, a chute for discharging sand into a flask, a constantly moving conveyor interposed between therebeneath.

HENRY A.

whereby the flasks are free to move away from 'said conditioning unit and said chute to transfer

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