US2968846A - Foundry molding machine - Google Patents

Description

Jan. 24,1961

| F. MILLER 2,968,846

FOUNDRY MOLDING MACHINE Filed March 5, 1958 4 Sheets-Sheet l FIG. i 29 INVENTOR.

LEON F. MILLER 0% az fiw ATTORNEYS Jan. 24, 1961 F. MILLER 2,968,846

FOUNDRY MOLDING MACHINE Filed March 5, 1958 4 Sheets-Sheet 2 FIG. 2

" INVENTOR.

LON F. MILLER BY AT TORN E YS Jan. 24, 1961 L. F. MILLER 2,968,846

FOUNDRY MOLDING MACHINE Filed March 5, 1958 4 Sheets-Sheet I5 f] INVENTOR.

LEON F. MILLER 2 7 BY ATTORNEYS Jan. 24, 1961 L. F. MILLER 2,968,846

FOUNDRY MOLDING MACHINE Filed March 5, 1958 4 Sheets-Sheet 4 FIG. 7

57 INVENTOR.

LEON E MILLER 59 AL 60 BY ATTORNEYS FOUNDRY MOLDING MACHINE Leon F. Miller, Rocky River, Ohio, assignor to The born Manufacturing Company, Cleveland, Ohio, a corporation of Ohio Filed Mar. 5, 1958, Ser. No. 719,333

5 Claims. (Cl. 22-42) This invention relates as indicated to a foundry molding machine, and more particularly to a machine designed to produce foundry molds without the necessity of employing the usual jolting operation.

It has been the general practice in the manufacture of foundry sand molds to fill a flask with sand while resting on a pattern board and to jolt the pattern and flask very forcibly to consolidate and compact the sand about the pattern. The flask is then elevated toward a squeeze head to perform a final heavy squeeze operation on the sand therein. Thereafter, the flask and mold are drawn from the pattern.

When in the past an effort has been made to rely upon a squeezing operation alone, without prior jotting, the results have seldom been satisfactory except on very shallow work. Nevertheless, it has long been appreciated that it would be highly desirable to eliminate the jolting operation if at all possible inasmuch as such operation is extremely violent and noisy, making for very unsatisfactory working conditions. Moreover, massive and expensive foundations are required for jolt molding machines, and the machines themselves must be of very rugged and expensive design. A squeezing operation, on the other hand, requires no such massive construction, tie rods ordinarily sufficing to provide the requisite strength, and there is no such noise as is produced by a jolting operation.

In view of the foregoing, an important object of the present invention is to provide a method of forming large sand molds of good quality without the necessity of jolting.

Another object is to provide such method which will produce molds having uniform mold surfaces in all parts of the same, even when a relatively complex pattern is employed.

Still another object is to provide a method which will produce a mold having means facilitating escape of gases through the sand during the pouring operation.

A further object is to provide a machine for carrying out the above method which will be rapid in operation.

Yet another object is to provide such machine which may readily be set up to accommodate patterns of different contours in a manner to ensure uniform compacting of the sand against all faces of such pattern.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. l is a side elevational view of a squeeze molding machine embodying the principles of my invention;

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Fig. 2 is a front elevational view of the machine of Pi l;

iig. 3 is a vertical section taken on the line 3--3 on Fig. 2, but showing an initial stage in the operation of the machine;

Fig. 4 is a section similar to Fig. 3 but showing a further stage in the operation of the machine when the final squeeze is performed;

Fig. 5 is a view generally similar to Fig. 3 but showing a modified arrangement of the expansible probes;

Fig. 6 likewise resembles Fig. 3 but shows still another optional arrangement of such expansible probes; and

Fig. 7 is an enlarged longitudinal section through one such probe.

Referring now more particularly to the drawing, the machine there illustrated embodying the principles of my invention comprises a conventional squeeze table 1 adapted to be raised and lowered by vertical reciprocation of squeeze piston 2 in cylinder 3. A pair of depending guide bars 4 and 5 are sleeved in brackets 6 and 7 respectively to ensure straight line reciprocation when drawing the completed mold from the pattern.

Columns 8 and 9 mounted on base frame 10 carry a pair of horizontal spaced upper frame members 11 and 12 respectively, tie rods 13 and 14 connecting such upper frame members to base 10.

The squeeze head 15 is mounted for horizontal reciprocation on roller trackways 16 and 17 carried by the upper head frame members 11 and 12 into and out of position directly above squeeze table 1. Flanges 18 and 19 on the head frame overlie the respective side edges of the squeeze head to support the latter against the squeeze pressure when piston 2 is reciprocated. A pair of doubleacting piston- cylinder assemblies 20 and 21 are mounted on the respective head frame members 11 and 12 with their rods such as 22 secured to upstanding brackets 23 and 24 respectively on the squeeze head whereby such squeeze head may be shuttled into and out of operative position.

Carried by superstructure 25 is sand measuring means comprising a sheet metal hopper 26 (adapted to form the lower portion of a bin, not shown) with clamshell gates 27 and 28 adapted to be opened and closed in conventional manner by double-acting piston- cylinder assemblies 29 and 30. Sand may thus be dumped into the subjacent measuring box 31 from which it may in turn be delivered to a flask carried on squeeze table 1 by opening of a louvered gate 32 through operation of piston-cylinder assembly 33. The above-described sand hopper and delivery mechanism is not itself a portion of the present invention and is described only in order that a more complete understanding may be had of the over-all operation of the machine.

A roller trackway comprising spaced parallel rails 34 and 35 with rollers 36 and 37 may be provided to facilitate entry of the flask 38 into the machine and delivery of the flask and completed mold therefrom. A fill frame 39 will ordinarily be provided supported on brackets such as 40, 41 and 42 for vertical reciprocation when engaged and lifted by flask 38, such vertical movement being guided by guide rods such as 43, 44 and 45. The fill frame or adapter 39 is, of course, dimensioned to constitute an upward extension of the flask walls.

Crossbars such as 46 and 47 may be provided within the flask 38 to assist in supporting the finished mold in well-known manner, if desired. Similarly, other crossbars 48 and 49 at right angles thereto may also be provided.

Carried by the squeeze head 15 are a plurality of squeeze p'ates or biscuits such as 50, 51, 52 and 53 arranged to project downwardly in regions intermediate the aforesaid crossbars within flask 38 when the flask is elevated to squeeze the sand therein. Some or all of such squeeze plates may be provided with downwardly projecting inflatable probes P which perform a function explained in detail below. Referring more particularly to Fig. 7, each such probe may comprise a tubular metal coupling 54 threaded into plate 55' constituting the lower portion of one of such squeeze plates or biscuits, such coupling having a further thinner downward extension 56 welded thereto. An inner metal tube 57 open at its upper end is there threaded within coupling 54 so as to clamp an elongated distensible balloon 58 therebetween, such hal'oon fitting closely over such inner tubular member 57 and the rounded plug 59 which is fitted within the'l'ower end of the latter. Such plug has a T-channel 6i) therethrough so that fluid under pressure admitted through inlet 61 may pass through the interior of tube 57 and passage 60 to expand or distend the balloon 58. The resiliently distensible flexible membrane forming such baloon will ordinarily be of rubber or equivalent material such as neoprene.

Operation Further details of the construction may best be understood from an explanation of the operation of my new foundry molding machine.

Having particular reference to Figs. l4 inclusive and 7 of the drawing, the machine will be set up by mounting a pattern 62 upon a pattern board 63 on table 1 and then rolling an appropriate flask 38- on roller conveyors 36, 37 into position direct y above such pattern board and directly beneath the fill frame 39. Upon now admitting fluid pressure to squeeze cylinder 3, the pattern board is elevated to engage the underside of flask 38 and lift the latter from its supporting conveyor. Shortly thereafter, the upper edge of the flask engages the lower edge of the fill frame 39, and the flask and fill frame are thereafter elevated together (Figs. 1 and 2).

The measuring box 31 has previously been fiiled with sand through opening of the clamshell hopper gates 27 and 28, and such gates have subsequently been closed. Now, piston-cylinder assembly 33 is operated to open the louvered bottom of such measuring box to permit a predetermined quantiy of molding sand to be delivered to flask 38 and fill frame 39.

The squeeze head has been in inoperative position during these proceedings (to the left as viewed in Fig. 1) and has had appropriate squeeze plates and probes mounted thereon. It is now shutted to the right into the position shown in Figs. 1 and 2 preparatory to performance of the initial squeeze operation. As piston 2 continues to rise, carrying with it squeeze table 1, pattern board 63, pattern 62, flask 38 and fill frame 39, the probes P first enter the loose sand S within the fill frame and flask, such probes, of course, being rig'd and relatively narrow (Fig. 3). With further rise of the squeeze table, the squeeze plates such as 50, 51 and 52 now engage the upper surface of the sand and operate to compact the latter within the flask against the pattern 62, this being comparable to the squeezing operation commonly employed subsequent to a joting operation in conventional machines. As soon as this initial squeezing operation has been performed and while maintaining the squeezing pressure, fluid under high pressure is admitted to the interior of each of the probes P to expand the distensible balloons or covers in the manner illustrated in Fig. 4. The probes will have been selected and arranged to extend toward the pattern 62 in regions generally uniformy spaced from the latter and particularly in regions where the sand is of greatest depth. The expansion of the probes, of course, produces further final compacting of the sand against the faces of the pattern, and it has been found that the balloons when thus expanded will assume a shape or form :generally conforming to the pattern contour although,

of course, spaced therefrom. The fluid is now e3 hausted from such probes to collapse the baloons or covers 58 and squeeze piston 2 is lowered to withdraw such probes from the compacted sand. As the squeeze table continues to descend, the fill frame 39 is next picked up by the brackets such as 40, 41 and 42 and thus separated from the flask 38 which continues to descend until it rests upon its roller conveyors 36, 37. Further descent of the squeeze table now serves to draw the pattern 62 from the mold, and the flask with the completed mold therein may be rolled from the machine to make place for an empty flask rolled in from the other side.

The cavities within the sand body of the mold produced by expansion of the probes are too small substantially to weaken the latter, and have the advantage of faciitating escape of gases through the sand from the mold cavity during the subsequent pouring operation.

It will readily be understood that in many operations the probes may be mounted directly on the squeeze head without employment of the individual squeeze plates or biscuits. The particular disposition of the probes will generally depend on the conformation of the pattern employed. Thus, as shown in Pig. 5, forexample, the pattern 64 may be of a shape rendering it advisab'e to insert probes P laterally through corresponding orifices in the side walls of the flask 38 as well as providing'a central probe on one of the squeeze pistes 65. It will readily be seen that the arrangement illustrated in Fig. 5 ensures more uniform compacting of the sand against certain surfaces of the pattern Where insufiicient effect is obtained through employement of the squeeze head aione. With certain types of patterns such as 66, 67 (Fig. 6)., it is advisable or more convenient to mount the probes P on the pattern board 63 itself, thereby to obtain the desired lateral compacting action against the pattern surfaces. It will readily be appreciated from a consideration of Fig. 6 that the effect of such probes is to ensure a compacting action on the sand substantially at right angles to that afforded by the squeeze plates 68, .69 and 7d. Fluid pressure may be admitted to such probes through passage 71 within the pattern board leading to flexible hose 72. With this Fatter arrangement, it will be apparent that the probes are embedded in the Sand within the flask when the latter is filled, and it is not necessary to insert them into the already filled flask as shown in Figs. 3 and 4. Likewise, the probes will will be withdrawn from the finished mold simultaneously with the drawing of the pattern therefrom.

Naturally, various combinations of probe arrangements may be employed in addition to those shown and described by way of illustration, the arrangement normally being determined by the form of the pattern. In general, the arrangements generally exemplified by Figs. 3 and 6 are preferred to that of Fig. 5 inasmuch as the insertion and withdrawal of the probes laterally of the flask involve separate operations not occurring through normal operation of the machine.

While the probes may be inflated by means of high pressure air, hydraulic fluid such as water will normally be preferred as there is less danger resulting from accidental bursting of a balloon or diaphragm. While the sand may commonly be delivered into the flask in the manner illustrated and described, it may optionally be blown therein in the manner generally disclosed in my copending application Serial No. 520,714, now Patent No. 2,866,242, filed July 8, 1955, for Foundry Molding Process, the probes being expanded immediately upon completion of the blowing operation. In either case, the necessity of a prior jolting operation may be eliminated although, of course, if desired the sand in the flask may be first jolted or vibrated, then squeezed, and finally subjected to the further squeezing action obtained by expansion of the probes. When the probes have been withdrawn from the compacted body of sand, the small cavities left thereby may be filled with sand if desired, as by blowing, but this is not ordinarily necessary or desirable. The probes themselves, even prior to expansion, elfect a certain degree of local compacting of the sand to an extent not achieved by the usual squeeze plates or biscuits, but this is relatively unimportant compared to the final squeezing action resulting from expansion of the same. It will be appreciated by those skilled in the art that the final squeezing action of the squeeze head is effective to compact the sand more thoroughly in the upper region of the flask than around the lower ends of the probes (Fig. 4) so that subsequent expansion of the probes assists in compensating for this initial diiference. Flowability of the molding medium is not as important in my new method as when employing the usual joltsqueeze machines, and consequently I am enabled to utilize much stronger sands, i.e. a stiffer mix with appropriate binders. In most installations, however, the greatest single advantage of my new machine and method is the fact that superior molds of complex shape may now be produced without the necessity of employing the usually objectionable jolting operation.

Other modes of applying the principle of the invention may be employed, change being made as regards the de tails described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In a foundry molding machine having a vertically reciprocable squeeze piston, a squeeze head thereabove, a sand filled flask having a pattern positioned therewithin supported on a table carried by said piston, and means operative to reciprocate said piston to elevate said table and flask to squeeze sand in said flask against said squeeze head, said squeeze head comprising a plurality of depending squeeze plates, at least one of said squeeze plates having a rigidly internally supported expansible member mounted thereon and adapted to project into said sand filled flask and operative to compact such sand against a selected portion of the pattern face.

2. A foundry molding machine as set forth in claim 1 wherein said depending squeeze plates are so positioned with respect to each other and the rigidly internally sup ported expansible member is of such dimension as to provide a squeeze head generally conforming to the shape of the pattern.

3. In a foundary molding machine having a vertically reciprocable squeeze piston, a squeeze head thereabove, a sand filled flask having a pattern positioned therewithin supported on a table carried by said piston, and means operative to reciprocate said piston to elevate said table and flask, crossbars within said flask adapted to assist in supporting the finished mold, said squeeze head comprising a plurality of depending squeeze plates arranged to project downwardly in regions intermediate said crossbars when the flask is elevated to squeeze the sand therein, at least one of said squeeze plates having a rigidly internally supported expansible member mounted thereon and adapted to project into said sand filled flask and operative to compact such sand against a selected portion of the pattern face, the downward projection of said depending squeeze plates and the length of said rigidly internally supported expansible member being such to provide a squeeze head generally conforming to the shape of the pattern.

4. In a foundry molding machine having a vertically reciprocable squeeze piston, a squeeze head thereabove, a sand filled flask having a pattern positioned therewithin supported on a table carried by said piston, means operative to reciprocate said piston to elevate said table and flask, said squeeze head comprising a plurality of depending squeeze plates arranged to project downwardly within said flask when the flask is elevated to squeeze the sand therein, at least one of said squeeze plates having a rigidly internally supported expansible member detachably mounted thereon and adapted to project into said sand filled flask and operative to compact such sand against a selected portion of the pattern face, the downward projection of said depending squeeze plates and the length of said rigidly internally supported expansible member being such to provide a squeeze head generally conforming to the shape of the pattern.

5. In a foundry molding machine having a vertically reciprocable squeeze piston, a squeeze head thereabove comprising a plurality of squeeze plates, a flask and pattern supporting table carried by said piston, means operative to reciprocate said piston to elevate said table and flask to squeeze sand in said flask against said squeeze head; elongated rigid metallic probe means mounted on said squeeze plates for introduction Within the sand within said flask when the table is thus elevated, and fluid pressure inflatable means carried by said probe means for expansion when thus introduced within the sand in said flask, said squeeze plates and probe means being so positioned and arranged jointly to provide a squeeze head contour generally conforming to the shape of the pattern.

References Cited in the file of this patent UNITED STATES PATENTS 989,578 Deville Apr. 18, 1911 1,537,860 Miller May 12, 1925 2,061,280 Lawlor Nov. 17, 1936 2,328,769 Anzin Sept. 7, 1943 2,698,976 Taccone Jan. 11, 1955 2,812,560 Taccone Nov. 12, 1957 2,835,004 Whitesell May 20, 1958 2,857,636 Whitesell Oct. 28, 1958 2,864,136 Taccone Dec. 16, 1958 FOREIGN PATENTS 527,222 Germany June 15, 1931 518,605 Canada Nov. 15, 1955

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