US3556196A

US3556196A - Method for automatic production and transportation of flaskless sand moulds in metal casting

Info

Publication number: US3556196A
Application number: US753640A
Authority: US
Inventors: Eugen Buhler
Original assignee: Individual
Current assignee: Individual
Priority date: 1967-08-18
Filing date: 1968-08-19
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19
Also published as: GB1233441A; US3744549A; FR1584384A

Abstract

In a method for producing and conveying horizontally divided flaskless sand molds, the molding sand is pneumatically introduced into mold frame cavities formed above and below a laterally moving match plate having a pattern on both sides and terminated by vertically moving mold frames and vertically moving press dies cooperating with said mold frames. The molding sand is pressed by a corresponding relative movement between said press dies and match plate, after which the match plate is separated from the mold halves by a corresponding relative movement between the press dies and the mold frame on one hand, and the match plate on the other. The match plate is then moved laterally into its rest position and the mold is closed, if necessary, after the insertion of cores. The finished closed mold rests on the bottom press die which is substantially flush with the upper edge of the lower mold frame, and is then displaced laterally from the molding position by the match plate as it returns from its rest position. The ejected finished mold is added to a mold train, and the finished mold is at least supported on two sides by supporting means.

Description

United States Patent [72] Inventor Eugen Buhler Weg zur Walk 96, Burtenbach, Kreis, Germany [21] Appl. No, 753,640

[22] Filed Aug. 19, 1968 [45] Patented Jan. 19, 1971 [32] Priority Aug. 18, 1967, Apr. 27, 1968 [33] Germany [31] 1,583,526 and 1,758,245

[54} METHOD FOR AUTOMATIC PRODUCTION AND TRANSPORTATION OF FLASKLESS SAND 3,273,207 9/ l 966 Taccone l64/29X 3,293,703 12/1966 Taccone 164/160 FOREIGN PATENTS 603,754 8/1960 Canada 164/40 912,608 12/1962 Great Britain 164/180 Primary Examiner-J. Spencer Overholser Assistant Examiner-JOhn E. Roethel Attorney-Holman, Glascock, Downing and Seebold ABSTRACT: [n a method for producing and conveying horizontally divided flaskless sand molds, the molding sand is pneumatically introduced into mold frame cavities formed above and below a laterally moving match plate having a pattern on both sides and terminated by vertically moving mold frames and vertically moving press dies cooperating with said mold frames. The molding sand is pressed by a corresponding relative movement between said press dies and match plate, after which the match plate is separated from the mold halves by a corresponding relative movement: between the press dies and the mold frame on one hand, and the match plate on the other. The match plate is then moved laterally into its rest position and the mold is closed, if necessary, after the insertion of cores. The finished closed mold rests on the bottom press die which is substantially flush with the upper edge of the lower mold frame, and is then displaced laterally from the molding position by the match plate as it returns from its rest position. The ejected finished mold is added to a mold train, and the finished mold is at least supported on two sides by supporting means.

PATENTEEDJA'MQIB?! T f 3636196 sum 111G513 V IN V EN TOR.

PATENIEU JANIQIQI I Sum 020F11- FIG 4 FIG. 2

IN VEN TOR.

PATENIEDJAMQIQII sum 13m 13 INVENTOR.

The invention concerns a method and an apparatus for the automatic mechanical production as well as for the conveyance of horizontally divided fiaskless sand molds.

In the two us. Pat. Nos. 1,291.996and 1.091 .020 are already described machines, operated rhythmically by apressuremedium, for-theproduction of flask less horizontally divided sand molds, whichhave two mold frames arranged The object of the present invention is, o"n the one hand, to

achieve a fully automatic operation in the production of horizontally divided molds and a larger castings thereby avoidabove and below a horizontal plate-that can. be swung out in a horizontal plane, moved vertically, and which cooperates with vertically moving press dies. v a a These known mold-making machines permit the semiautomatic production or flaskle'ss horizontally divided casting molds, but they have the disadvantage that the 'molding'sand must be manually placednin the mold frames; that the finished ntolds can only be conveyed on base plates; and furthermore that the finishedmolds must be covered with so-called jackets before theyare-moved away inorder to be able to withstand thepressure of theliquidmetal during casting. The liftingof the finished molds from the mold nakingmachine, the'pla'cement of the latteron a conveyor device and the placing of the jackets over the finished molds mustbe effected byhand. The H great'amount of manual work involved in the known methods ing base plates and jackets, and on the other hand, to make such an automatic process economical by rapid pattern changes, notonly for the production of large runs. but also for 'the production of small runs or single pieces as well as for small castings.

The present invention relates to a method for the mechanical production as well as for the conveyance of horizontally divided flaskless sand molds, where the molding sand is pneumatically introduced into two mold frame cavities formed above and below a laterally moving match plate having a pattern on both sides and terminated by vertically moving mold frames and vertically moving press dies cooperating with said frames The molding sand is pressed by a corresponding relacause loss of timeand highwage costs andprecludes the'effit n w of automatic procedures. Furthermore. the supply of-a great number of base plates and jackets requires high investment costs. 3 Y

in cen ral Pat.- No. l 950,560 is described a chute mechanism by means of which the lowermold frame and'then the upper mold 'frame'can be charged by machines of the above deseribed 'type with molding sand. U.S. Pat. No.'

3,229,366Ydescribes a mold-making machine of the above horizontal in molding position which can be swung'out into a vertical plane,' where the molding sand is pneumatically has the disadvantage that because of 'thes'uccessive filling of the lowerupper mold frame there is still a loss of time.

.tive movement between these press dies and the match plate,

afterwhich the match plate is separated fromthe mold halves by a corresponding relative movement between the press 'dies and the mold frame on the one hand, and the match plate, on the other hand. The match plate is then moved laterally into its rest position and the mold is closed, if necessary, after the insertion of cores. after which the finished mold is exposed by relative movement between at least one press die and the two mold frames, tobe moved away. Such a method is characterized according to the invention by the fact that the finished mold resting after its ejection on the bottom die, which is subthe match plate from its rest position and is introduced as a newly added part to a. mold train moving past the finished molds are supported on at least two 'sides by supporting i mentioned type. but with a pattern plate (match plate) The second method'has the disadvantagethat the molding sand blasted into the interior of the? mold frames mixes with thecornpressed ai'r'conveying it and the pattern halves are damaged by theresulting erosive action ofthesand blower,

and also difficulties are "encountered in eliminating the entrained air. Both of the last mentioned methods have the same disadvantages as the above described methods, namely that the finished mold must be transferred from the mold making machine to the conveyor device by hand. and they require base plates and jackets. The Swiss. Pat. No. production of vertically divided flaskless sand molds where the molding sand is introduced by blasting into a cavity formed between two vertical match plate halves and is sub sequently pressed'by moving the two match plate halves and swinging away one match plate half from the finished mold body, thelatter beingpushed by horizontal movement of the 364,078 describes a plant for the means.

By the term mold train" is to be understood a series of individual finished molds which directly touch each other with their unreinforced end faces, or a series of finished molds that are supported on all four sides by supporting means and whose respective adjoining end face supportingmeans touch each other. t 1

qThe invention also relatesto a plant for carrying out the method according to the invention with a sand mold-making machine operated cyclically by a pressure medium, with mold frames moving vertically above and below a laterally moving match plate, which is horizontal in molding position, and

.cooperating with respective vertically moving press dies, as well as with a device for the supply of molding sand to the mold frame cavities. Such a plant is characterized according to the invention by the fact that a preferably plate-shaped sliding die for the ejection of the finishedmolds is arranged on I one side of the match plate moving in a horizontal direction,

] the invention is preferablydesigned as a hollow body and has other match plate half onto a horizontal conveyor track where a it joins as a newly added'part of mold train moving toward a casting pit. This known method has the advantage of being completely automatic, butbecauseof the "vertical divisionofthe mold,'there are difficulties regarding the insertion of the core and the production'oflarger castings, since the finishedmold bodies cannot'withstand high internal pressure because they are not supported in any way. I

All the above described known methods have the disadvantage that the change of the patterns is cumbersome and timeconsuming. and the known semiautomatic methods are therefore uneconomical in the production of a smaller series of castings.

and that a conveyor track for the mold train receiving the finished molds and passing by a castingpit is arranged laterally of the moldmaking machine in the direction of motion of the sliding die and in a plane which the press surface of the bottom die assumes in its direction of ejection of the finished mold, the finished molds being supported at least on two lateral sur faces by supporting means being advanced along this conveyor track.

The match plate of the mold-making machine according to on its upper and lower plate-surface a plurality of apertures,

preferably uniformly distributed over the respective plate surface, into which can be introduced corresponding holding and/or fixing means for exch angeable patterns. In a match plate designed as a hollow body, the cavity of the match plate can be connected according to another feature of the inven- .tion over corresponding controllable switching elements selectively to a vacuum or pressure gas source. The match plate can have a plate frame into which upper and lower dividing plates can be inserted.

Above and below the guide section of the mold-making machine determining the departing position of the match plate can be preferably arranged, according to another feature of the invention, swing-away infrared radiators for heating the match plates.

The supporting means for the finished mold have according to the invention the form of clamping plates, guided along the conveyor track for the mold train and preferably provided with adhesive tips and cooperating in pairs, which can be tipped about a horizontal axis. The clamping plates are preferably arranged in known weight irons, guided above the conveyor track for the mold train. that they are opened up automatically during their change. According to a preferred embodiment of the invention, a number of supporting units are provided which have two or four clamping plates opposing cach'other in pairs and serving as a support for the respective finished mold, these clamping plates being articulated by means protruding beyond this weight plate being articulated on cross guide rods, preferably self-locking in the manner of toggle levers, whose respective other ends are in turn articulated on a weight connected with a trolley head and moving along a vertical guide securedwith its bottom end on the weight plate and having a stop at the top. This movement is such that in case the rollers of the trolley head rest on a longitudinal guide extending over the conveyor track of the mold train, the weight plate is held in a position detached from the top surface of the finished mold and the clamping plates in a spread position exceeding the respective horizontal dimension of the finished molds. When the trolley is released downward, the weight plate is placed on the respective top surface of the finished mold and the clamping plates are thus pressed against the respective lateral faces of the finished mold.

The feeding power necessary for feeding the mold train is preferably derived, according to the invention, by the mutual end faced bearing of the supporting means for the respective finished molds from a power source which effects, on the one hand, the lateral ejection of the last finished mold from the molding machine, and on the other hand, by acting on the respective supporting means of the second last ejected finished mold to advance of the entire finished mold train by one finished mold length.

The arrangement for the pneumatic filling of molding sand into the mold frame cavities of the mold making machine has, according to the invention, a gas compressor, a pressure gas tank, and a molding sand tank filled by a filling device from the molding sand bunker and arranged laterally of the mold making machine. Preferably two pressure gas lines are located between the pressure gas tank and the molding sand tank for admitting pressure gas over one or two controlled valves. If necessary a vacuum tank and a vacuum line can be connected with the interior of the match plates and provided with at least one control valve. Furthermore, an upper and lower molding sandline associated with the upper end lower mold frame cavity is included.

In an embodiment of the plant according to the invention the two molding sand lines are arranged laterally in known manner in such a way that they are in communication with the respective mold frame cavities through lateral slots in the mold frames of the molding machine when these frames are in filling position. In a preferred embodiment of the plant according to the invention, the two molding sand lines are connected to the upper and lower sand chambers of the moldmaking machine, which in turn are in communication with the mold frame cavities through openings of the two press dies. The sand chambers of the mold making machine can have each an upper and lower telescopic extension whose interior is in communication through openings of the respective plateshaped press die with the respective adjoining mold frame cavities. According to a preferred embodiment of the invention, the two molding sand lines, a connecting line connecting these sand lines with each other, and the upper and lower sand chamber of the mold-making machine are combined in the vertical plane to a C-shaped sand tank forming the mold making machine frame, which has at the top the filling device connected with the sand bunker and one of the two pressure gas nipples, also at its two leg ends the two sand chambers with the respective press dies, furthermore in its horizontal center plane the match plate guide, and on the lower arc of the C the other pressure gas line nipple.

In order to accelerate the production of the casting molds and the pouring of the finished mold trains, several conveyor tracks for the finished mold trains. which can be displaced transverse to their longitudinal-axes relative to the mold-making machine, can be alternatively used.

Other features and advantages of the invention will result from the following specification of some embodiments with reference to the attached drawings, in which:

FIG. 1 shows a partial section of a schematic elevation of one embodiment of the mold-making machine for sand mold production and conveyor plant according to the invention;

FIGS. 2 to 6 show a simplified schematic lateral elevation, similar to FIG. I, which represents the machine corresponding to its operation successively in pressing position, in lifting position, in core-inserting position, in mold-closing position and in mold ejecting position;

FIG. 7 shows a schematic elevation of the mold-making machine as well as of the respective conveyor track for the finished mold train of the mold-production and conveyor plant during the ejection of a finished mold, turned by 90 about the vertical axis of the machine as compared to FIGS. 1 to 6;

FIG. 8 shows a schematic cross section through the conveyor track for the mold train of the plant according to the invention with the supporting means according to the invention for supporting the sidewalls of the finished molds;

FIG. 9 shows a partial section of a schematic top view of a match plate, preferably to be used in combination with the plant according to the invention, a so-called "top plate" being inserted in the left half of the drawing;

FIG. 10 represents a section along the plane X-X in FIG. 9, seen in the direction of the arrows, which shows that in addition a so-called bottom plate" is inserted in the left halfof the lustrated in FIGS. 9 to 12 with the attached inlet, pattern, and

a pattern unit according to the invention in the production ofa mold half;

FIG. 14 shows a schematic side view in the direction of the arrow XIV in FIG. 9, in which the top and bottom part of the match plate is shown in a partly folded state;

FIG. 15 shows a schematic perspective view of a preferred I embodiment of the match plate according to the invention used in combination with a mold-making machine according to the invention;

FIG. 16 shows a schematic partial side view of another embodiment of the sand mold production and conveyor plant according to the invention;

FIG. 17 shows a partial section of a top view of the plant represented in FIG. 16;

FIG. 18 shows a partial section along the plant XVIII-XVIII in FIG. 17-,

FIG. 19 shows a partial top view of the plant represented in FIG. I6 seen in the direction of the arrow XIX in FIG. 16;

FIG. 20 shows a schematic section along the plane XXXX in FIG. 16, seen in the direction of the arrows;

FIG. 21 shows a schematic partial vertical-longitudinal section through a modified embodiment of the mold frame and press die arrangement of a mold making machine according to the invention; and

FIGS. 22 to 26 shows respectively partial verticaI-longitu dinal sections through the mold-making machine of the sand mold production and conveyor plant represented in FIGS. 16 to 20 in various operating position.

FIRST EMBODIMENT With references toFIGS. 1 to 8 of the drawings an embodiment of asand mold production and conveyor plant according to the invention will now be described. M w

FIG. 1 shows a part of the mold-making and conveyor plant according to the invention showing the foundationframe of the mold-making machine according to jthe invention with cross yoke A. ln'this foundation frame is held for vertical displacement a top die'Ba, which is fixed, for example, in this embodiment of the invention during the working cycle of the machine. This top die can be set at different levels for the production of patterns of different profile heightby'means o fa hydraulic drive Fa, so that the workingstrokes' of the machine and their time intervals are kept as short as possible. An upper mold fram'e'Ca. is vertically displaceable with respect to top die Ba by means of a hydraulic drive Eaf A double-sided match plate D is at the beginning of the working cycle of the machine in the position represented in' FIG. I of'the drawings, in which the molding'sand is introduced pneumatically into.

terposed match plate D. In this state the molding sand is introduced pneumatically by means of :the' device N.-This is the basic first step for the pressing process.

FIG. 2 shows the position of the mold frames Ca and Cb after the pressing. In the compression of the molding sand. the bottom die Bb has moved'upward relative to the lower mold .frame Cb, which is held somewhat by a certain initial stress of the hydraulic drives Ea, Eb and has thus been protected from uncontrolled sliding down..for' example, by its own weight. The bottom die Bb haslifted the'match plate D from its rails and taken it upwards together. with'th'e upper mold frame Ca relative to thestop die Ba, so that the molding sand contained the machine. The bottoindie Bb of the machine can be moved I verticallyj up 'andd own 'in known manner .by means of a hydraulic drive Fb. Aflower frame Cb is vertically displaceable relative'to Eb. n I, l p v p FIG. 7 of the drawings shows an ejectiori de'vice G for the this bottom die Bb by means'of a hydraulic drive match plate'D of the niachine'in a schematic representation.

the machine the bottom moldframe together with the bottom die Bb can pass during the pressing ope'rationthrough the frame-shaped truck" lifting the ina'tch plate D upwards and pressingitagainst the top'die Ba. t i

F IGS .7 and ,8 of the drawings alsoshow the con veyor belt I of the mold-making plant according to the invention forming the conveyor track of the mold train, on which ejected finished molds are arranged. The edges, of the horizontal separating joints of these flaskless sand molds have, according.

to the invention, complementaryibeveis L, which serve to fix the upper and lowermold halves during the feeding'p'rocesses. They have been omitted for clarityssake" in FIGS. 1 to 7, in the latter in the match plate. w V

FIG. 8 shows a schematicYcross section through the conveyor belt l and also supporting means according tothe invention for the lateral support of the finished molds resting on the conveyor belt. These have, for example, the form of clamping plates M, as mentioned above, which are pressed by means of a controllable linkage, according to the invention, laterally against the finished molds sothat the latter can withstand the casting pressure deformation force resulting from the feeding process. These clamping plates M can also be actuated, if this seems advisable, from the top, for'example by using known weightirons as it is shown on theright of FIG. 8. 1

FIG. I of the drawings also shows the pneumatic filling device N for the molding sand of the moldmaking plant according to theinvention. The molding sand is accelerated during the filling process simultaneously with air from the, top and from the side. In this way a uniform filling of both mold frames I Ca and Cb is achieved. Louvered diaphragms 0 ensure the proper air flow. v t

- FIRST EMBODIMENT OPERATION The individual working cycles of the mold-making plant ac- FIGS. 1 to 7 of the drawings. l t

' FIG. 1 shows the first working stage. Here the upper mold frame Ca and the lower mold frame Cb are applied to the in impulse, slightly trailing behind the inserting movement of the match plate, is imparted to the conveyor belt, the power of the in the upper mold frame has also been compressed. A slight jbackpressure can be exerted by means of the upper hydraulic match plate D is again placed on its frame-shapedtruck or, if

it is designed itself as a truck, on the rails and is subsequently movedto the rear by means of the horizontally acting hydraulic drive indicatedat G in FIG. 7 of the drawings. In'case the match plate Dis designed itself as a truck, a hook-shaped vertically detachable connection is provided between this hydraulic drive and the match plate D, likewise indicated in FIG.'7 (not numbered),

The removal of the match plate D results in the core-inserting positio'n represented in FIG. 4. Cores can be inserted either by hand or by ,means of a :special core-inserting mechanism. Subsequently the bottom die Bb with the lower mold frame Cb and the lower mold half moves up untilit bears on the upper mold half, the two mold frames Ca and Cb being simultaneously pulled back or subsequently pulled back by means of the hydraulic drives Ba and Eb so that they release the entire mold. w

1 The mold is thus closed and'rests in the position shown in FIG. 5 on the bottom die Bb. In its following downward move ment it is disengaged from the top die. I

' Y The bottom die subsequently moves so that it is aligned wit the conveyor belt I. This position represented in FIG. 6. t

If the-match plate D and its framesshaped truck are inis the ejection position troduced again by means of the hydraulic drive G, the finished mold K is ejected at the same time onto the conveyor belt I as shown'in FIG. 7.

The'two'mold frames Ca and Cb are subsequently raised and lowered again by means of their hydraulic drives Ea and Eb until they bear again'on the match plate D, the starting position according to FIG. I has been reached again and the working cycle can start anew.

The finished molds form, as shown in FIG. 7, a closed mold train having two abutting surfaces each of the four lateral surfaces of the finished molds supporting one another. The contact pressure of the molds, which is equal to the ejection power and the driving force required for nondriven conveyor belt must be limited so that overstress of the molds which might result in lateral destruction is avoided. To this end, the

conveyor belt I can be driven or supplemented, for example by means of a stepping mechanism, whose activity is preferably started by overpressure of the pre sure medium actuating the hydraulic drive G.

The arrangement can be such that .a synchronous motional insertingmovement of the match plate ,being so limited that I cording to the invention will now be described on the basis of destruction of the finished molds' is avoided. The driving power of the conveyor belt is preferably obtained from a power source producing power in excess of the introduction of the match plate. a

The support of the exposed other two sides of the molds is effected, as mentioned above, by clamping plates. These run in synchronism with the conveyor belt I. They can be secured by a linkage on the belt or they can be articulated on weight irons guided at the top, or they can be secured on a separate belt, which can follow, for example, by friction contact.

The control of the working cycle of the mold making plant according to the invention can be effected in a simple manner, for example, by limit switches over control pistons by means of a pressure medium. The thrusts of the various hydraulic drives, for example of the hydraulic drives Ba, Bb, Fa, Pb and G, can be limited by known means, for example, overflow valves.

The height and area of the molds can be increased by corresponding dimensioning of the parts of the plant, for example, of the mold frames, press-dies, conveyor belt etc. up to orders of magnitude which were possible so far only in automatic plants with mold flasks.

The double-sided support of the finished molds advancing on the conveyor belt I can be effected in a modification of the invention, instead of by the above described clamping plates, by conveyor belts arranged at both sides of the finished mold train and extending parallel to the conveyor belt 1, whose bank surfaces are vertical. Such supporting conveyor belts can be either driven or nondriven. They can be covered, if necessary, with spur plates extending perpendicularly to the conveyor belt surfaces, which reach between the individual finished molds and support their end faces.

Both the conveyor belt I and the above mentioned supporting conveyor belts can be'supported to such an extent by closely arranged guide rollers that they lay practically in a plane surface. They can have, for example, the form of endless steel belts.

The clamping plates used according to the invention preferably for supporting the finished mold train on both sides can be made tiltable about axes parallel to the direction of conveyance in the embodiment of the invention described here, and their respective degrees of tilting or pressing against the outer walls of the finishing mold train can be controlled, for example, by a cam track extending parallel to the conveyor belt.

Instead of a single conveyor belt 1, several conveyor belts can also be used which can be displaced transverse to the direction of conveyance and which can cooperate selectively with the mold making machine according to the invention.

The device according to the invention for the pneumatic feeding of the molding sand into the two mold frame cavities has preferably the form of a rotatably or fixedly mounted box or drum-shaped tank in which are arranged louvered air baffles, and in which the molding sand is accelerated by compressed air introduced simultaneously both from the top and from the side.

As it can be seen from FIGS. 1 to 6 of the drawings, the hydraulic drives effecting the vertical displacement of the two mold frames are arranged parallel to the hydraulic drives effecting the vertical displacement of the two press dies. As it will be described below, a concentric arrangement of the hydraulic drives for the press dies and the mold frames can also be provided instead of the parallel arrangement.

MATCH PLATE The match plate 4 and the truck carrying the match plate in the ejection position of the machine can have on the side facing the conveyor belt I, a sliding die, for example, in the form of an easily moving articulated vertical surface, which bears during the ejection of the finished mold on the vertical outer mold surface facing it.

With reference to FIGS. to of the drawings, the detail of a match plate according to the invention will now be described, which can be used in combination with the above described sand mold production and conveyor plants according to the invention represented in FIGS. 1 to 9, and also with other embodiments of such a plant, as will be described more fully below.

The preferred embodiment of a match plate according to the invention, represented schematically in FIGS. 9 to 14, has

a plate frame which consists of a main frame part I and two upper and lower frame parts 1' and 1 respectively articulated thereon. The top and bottom edges of the main frame part 1 of the match plate and the respective surfaces of the upper match plate frame part I and of the lower main frame part I" bearing thereon are so ground that the tight mutual bearing of these match plate frame parts shown in FIGS. 10, l1 and 12 of the drawings is ensured. On one side of the main frame part I of the match plate frame are secured, for example, four slightly elastic holding angles 2 which are pushed toward each other by their slight spring effect in the direction of the arrows P indicated in FIG. 10. At the free ends of these holding angles 2 are secured axle pieces 3 whose salient free ends, on both sides, are designed as axle journals 3a. On oneside each of the top and

bottom part

1 and 1" respectively of the match plate frame are secured, for example, two rigid hinge arms 4 which form an integral part with meshing gear wheels 4a in whose hub bores are supported the axle journals 3Z1 of the axle pieces 3. The dimensions of the parts are such that, when the top part 1 of the match plate frame and the bottom part 1" of the match plate frame are turned so that they bear on the two ground surfaces of the main part of the match plate frame, the holding angles 2 on both sides are elastically bent against the directions indicated by the arrows P, so that they tend to press the top part 1' and the bottom part I of the match plate frame against the respective bearing surfaces of the main part I of the match'plate frame. On the other hand, the elastic holding angles 2 have a tendency, when top part 1' and bottom part 1" of the match plate frame are folded away from the main part 1 of the match plate frame, to press the loosely meshing gear wheels 40 into a tight mutual engagement to make sure that the movements of the top part 1' and of the bottom part 1" of the match plate frame are specially synchronized to ensure a complete weight balance in favor of a low energy expenditure for moving these parts. On the sides opposite the sides of the top plate 1' and of the bottom plate I" of the match plate frame holding the respective hinge arms 4 are likewise secured limited elastic clamping parts 5 whose free ends are provided with bearing bores 5a in which are sup ported the journal-shaped free ends 6a of clamping pieces 6, which in turn can be pressed together by means of a clamping screw 7. This clamping screw 7 passes, on the one hand. through a continuous bore of one clamping piece 6, and on the other hand, is arranged in a slot-shaped recess 6b of the other clamping piece so that it can be moved away to disengage the clamping connection. By tightening the clamping screw 7, a tight mutual bearing of the associated bearing surfaces of the main part 1 of the match plate frame, on the one hand, and of the top and bottom plate 1' and 1" respectively of the match plate frame, on the other hand, can be achieved.

The match plate is divided in the embodiment represented and described here by a

central holding bar

8, 8' and 8" respectively into two halves so that the top and bottom side of the match plate according to the invention receiving the pattern change are each divided into two parts. Such a subdivision is naturally not compulsory and can be omitted by eliminating the holding bars 8, 8, 8". On the other hand, a further subdivision of the top and bottom sides of the match plate according to the invention by additional holding bars, not shown, in longitudinal and transverse directions is also possible within the framework of the invention. The holding bars 8, 8', 8" are preferably detachably mounted on the frame parts I, l and 1" of the match plate according to the invention in a manner not shown in the drawing. The top and

bottom plates

1 and 1" respectively of the match plate frame and the top and bottom parts 8' and 8" respectively of the holding bars are provided with corresponding shoulders or ledgeshaped projections on which rest a so-called top plate" 9 and a so-called bottom plate 9", which are connected by detachable fastening means, not shown in the drawings, with the top part 1 and the bottom part 1" respectively of the match plate frame. The top whichjare indicated in FIGS. 9an'd ll) of the drawings by -brokenlines. a

.-n the insides of the main part l of the match plate frame as well as on the holding bars 8, if any can be provided shoulders and holding strips respectively and 8a, which serve as a supportfor inner reinforcing plates 10. which, just like the holding bars 8. serveto increase the resistance of the match plate according to the invention against external pressure. The shoulder and holding" strips la and 80 also have the function, for reasonsto be discussed later,-of serving as a packing support for relief plates, if relief patterns must be molded with the a match plate according to the invention. a I Q On one or several of the outer four sides of the main 'part 1 each other in the form of'a square raster, as'it can be seen from FIG. 9. The change pattern halves to be secured on the top plate 9 and on the bottom plate 9" are preferably "provided in known manner with'cylindricalfitting pins 12a (FIG. 13 which can bejntroduced intothe fastening apertures 12'. The fastening of the change pattern halves on the top plate 9', and bottom plate 9 can be effected with screws, threaded bolts, clamping bolts, clamp. clips or byimagnetic force, in

which latter case the top, plate 9' and the bottom plate 9" must be made of corresponding magnetic material. Apart 4 from thefpossiblemagnetic fastening of the change pattern halves, however, the top plate 9 and thebottom plate 9'' ean also be made of a different material, for example,of wood or of plastic. 4 a

; The fastening apertures l2'can be numbered continuously,

' asjit canbe seen from H0. 9. Accordingto the invention, an r additional trialplate can be 'provided in this case, which is not represented in th'edrawings, whose top and bottom-surfaces,

plate 9 and bottom plate 9" I respectively are the carriers-of thechange pattern halveswith flaskless sand mold making machines, the feeding of the molding sand by means of compressed air into the mold frame and thus leads not only to a marked'acceleration of the feeding process, but also helps substantially to reduce or eliminate completely the difficulties encountered normally in these leases when molding complicated patterns. It is readily understandable that during the evacuation of the interior of the match plate according to the invention the elimination of the .compressed air necessary for filling the molding sand into the mold frame is effected through the uncovered fastening apertures 12 of the top plate 9' and bottom plate 9" and that it is detachment of the finished mold from the pattern is greatly facilitated, since the compressed air issuing from the interior of the match plate through the apertureslZ not covered by the pattern provides an air cushion below and above the two mold halves to be removed which and removal. 5 r v v :In'order to be able to limit the passage of air through the fastening apertures l2 of the topplate 9 and of the bottom plate 9" during the filling of the molding sand and during the detachment of the finished mold halves, it is possible according to the invention to'insert' known nozzle plugs 12b (FIG. l3),into the fastening apertures 12 not requiredfor fastening and fixing the change-pattern halves which permits only a limited passage of air through these apertures. These nozzle plugsare preferably designed as slotted plugs whose slot width is selected so narrow that the entrance of molding sand particles'into the hollow of the match plate during the evacuation of this hollow is avoided.

Despite the above described advantages. the design of the facilitates their detachment match plate according to the invention as a hollow body is not likewiseprovided with numbered'apertures, are identical in their dimensions, size, arrangement and numbering of these apertures with the top and bottom surfaces of the match plate accordingto the invention and which canbe" inscribed with wipe-off writing materials. This measure-according-to the'invention permits experimenting during the operation of the mold-making machine by means of the trial plate the respective optimum coveringof the pattern plate with the, respective patterns to be molded in the new series, and permits the marking of the fastening apertures necessary for fixing and fastening the pattern halves on the pattern plate. The. fastening of the pattern halves on the match plate according to the invention can then be effected in a very short time by usingthe "it possible to-outline the change pattern'half applied onthe trial plate, for example, with a crayon, andthus to determine a in a short time which fastening apertures are necessary for fastening and fixing the pattern halves on the match plate ac cording to the invention. a a a a e a The fastening apertures 12 of the pattern plate according to I the invention have another function, too,'however. As it can ble mounted on the match plate according to the invention.

This detachability of the top plate 9" and of the bottom plate 9" from the main part of the match plate is of particular importance, with a great subdivision of the match -plate cover marked numbers of the necessary fastening apertures. The inscribability ofthe top and bottom surfaces of the trial plate according to the invention with wipe-off writing materials makes surfaces by holding bars 8' and 8",when the match plate is to be covered simultaneously. with different series of difi'erent patterns ordifierent quantities ln these cases the time necessary for the pattern change by removing the respective top and bottom plate 9' and 9" and attaching another top and bottom plate already covered with the new pattern halves is substantially reduced. But where such cases do not appear, the fastening apertures 12 can be provided readily directly in the upper and lower bottom of a solid or hollow match plate as continuous holes. This has the result that the division of the match plate frame of the match plate according to the invention into a main part 1 and a top frame 1, as, well as a bottom frame part 1 is likewise not compulsory. This division, and particularly the simultaneous possibility of tilting away from the top part 1' and the bottom part 1'. of the match plate frame serve again merely to accelerate the change of the patterns and particularly to make the hollow of the match plate according to the invention accessible, vivhich is of particular advantage when relief plates are to be molded. FIG. 14 of the drawings shows the advantage of a weight-balance resulting from the symmetry of the folding away of the top plate 1" and of the to a vacuum and/or compressed air-source. Such an evacuation possibility of the interior of the match plate according to the invention facilities, particularly when used in combination bottom plate 1" of the match plate frame according to the invention.

If the evacuation or pressurization of the hollow of the match plate according to the invention is considered and the match plate frame is divided into a main frame part I and into a detachable and fold-away top frame part 1' and an identical bottom frame part 1'', it may be advisable to provide on or in the proximity of the mutual contact edges of these parts packing strips of suitable material, for example, of rubber.

FIGS. 9 to 14 of the drawings shows that a so-called runner" 13 is preferably detachably mounted on the top side of the top part I of the match plate frame. As it can be seen, particularly from FIG. 13, the runner 13 cooperates with a sprue 13a arranged for elastic displacement on the top die as well as, if necessary, with one or more correspondingly arranged risers, which are likewise arranged in suitable manner on the top die of the respective mold-making machine. Naturally several runners can be provided at a suitable point instead ofa single runner 13. FIG. 13 shows on the right side next to runner 13, a gate 13b attached on the top plate 9' by means of a fitting pin 12a, which is joined by a pattern 13c, likewise fixed with fitting pins 120 on the top plate. The invention also concerns the idea of using in connection with such a runner 13 or with several such runners one-piece pattern units 13d, which can likewise be seen in FIG. 13. These units consists, in the case of the top side of the match plate, of a gate, if necessary a feeder with inlet and the respective pattern half, the gate adjoining directly the respective runner 13. Due to such a measure according to the invention, the time necessary for changing the patterns is likewise reduced to a minimum.

These pattern units 13d are made of cast iron, brass, aluminum, wood or plastic, and are one piece or composed of several parts by means of a common holding strip. The units can consist of magnetic material, or can have a magnetic or magnetizable holding shoe, if they are to be secured by magnetic force on to the match plate.

MATCH PLATE IN USE In connection with FIGS. 14 and 15 of the drawings, the application of the match plate according to the invention in combination with the mold-making machine according to the invention as illustrated in FIGS. 1 to 8 will be described. As indicated in FIG. 14 the match plate 1 according to the invention rests on a slide frame 14 (broken lines) which can be dis' placed along horizontal guide rails 15. In FIG. 15 of the drawings the range of action of the mold frame and of the press dies of the respective flaskless mold-making machine is indicated by an upper and

lower mold frame

16 and 16" as represented by broken lines. As it can be seen from FIG. 15, two match plates 1A and 1B are arranged side by side in the slide frame 14. FIG. 15 shows furthermore that the slide frame 14 can be moved back and forth in the direction of arrow Q by means of a hydraulic drive (not shown in the drawing) between a position in which the match plate 1A is in the range of action of the mold frame 16' and 16" of the mold-making machine, and the represented position in which the match plate 1A is outside this range of action. According to the invention, the guide rails 15, which are likewise represented in FIG. 15, forms a part of another slide frame 17, which can be moved back and forth by means of a hydraulic drive, secured on the machine, along guide rails 19 transverse to the direction of arrow Q in the direction of the arrow R in such a way that, on the one hand, the match plate 1A can be brought in the represented position of the slide frame 17 into the range of action of the mold frames 16' and 16" of the mold-making machine, and on the other hand, in an unrepresented position of the slide frame 17, the match plate 18 can be brought into this range of action. Both slide frames 14 and 17 are so designed that the mold-making machine can cooperate unhindered with the respective match plate when the match plate 1A or 1B is in the above-mentioned operative position.

The last described double match plate arrangement according to the invention permits the pattern to be changed during the operation of the mold-making machine on the respective match plate which is not in operative position. while the other match plate moves in and out of the range of action in the working rhythm of the mold-making machine. Shutdown time for the change of the patterns is thus avoided.

With magnetic fastening of the pattern halves and pattern units on the match plate, the arrangement of a second match plate may be unnecessary under certain circumstances, since the pattern change can then be effected in a very short time in the extended state of the match during the operation of the machine.

In the arrangement described in connection with FIG. 15 of the drawings, it may be of advantage to arrange three or more match plates side by side on the slide frame 14, instead of only two, in which case the track 19 of the slide frame 17 must naturally be so dimensioned that one of the match plates according to the invention can cooperate with the mold-making machine, while a pattern change is effected on the other match plates during the operation of the molding making machines.

According to another feature of the invention, the slide frame 14 can be used as a sliding die for the ejection of the respective finished sand molds from the mold-making machine.

It follows from the foregoing considerations that the match plate according to the invention in its various embodiments, or the match plate arrangement according to the invention in its various embodiments, particularly in combination with flaskless sand mold-making machines, allows not only a considerable acceleration of the pattern change, but also leads to an acceleration and trouble-free performance of the molding process proper. The match plate and match plate arrangement according to the invention particularly in combination with fiaskless sand mold-making machines, a substantial contribution to increasing the economy of fully automatic casting plants.

The above described match plate according to the invention can be used not only in combination with mold-making machines of the type described in this connection, but also generally in combination with semiautomatic or automatic mold-making machines. In this application too, it offers all the above-described advantages.

SECOND EMBODIMENT In connection with FIGS. 16 to 18 of the drawings another embodiment of a sand mold production-and-conveyor plant according to the invention will be described. As far as parts are represented in these FIGS. which are identical with the parts represented in FIGS. 1 to 15, they have been provided with the same reference letters or reference numbers.

FIG. 16 shows just like FIG. 7 a side view a mold-making machine generally designated with 101, with an adjoining conveyor track for the finished molds, generally designated with 102.

The machine frame of the mold-making machine 101 is formed by the molding sand feeding device to be described later, particularly with reference to FIG. 18. The mold-making machine 101, like the mold-making machine described above with reference to FIGS. 1 to 7, has a top die Ba, a bottom die Bb, an upper mold frame Ca and a lower mold frame Cb. The vertical displacement of the lower mold frame Cb is effected by a hydraulic drive, identical with the hydraulic drive Ea (FIGS. 1 to 7), which is not represented for claritys sake in the drawings and which acts in opposite direction to Eb. The vertical displacement of the top die Ba is effected by means of a hydraulic drive Fa and that of the bottom die Bb by means of a hydraulic drive Fb acting in opposite direction. Preferably in the horizontal center between the two hydraulic drives Ea, Eb and Fa, Fb is fixedly mounted a horizontal guide 103 in which a match plate D designed as a truck is so guided that it can perform horizontal movements, but no vertical movements. The match plate D can have any of the forms described above in connection with FIGS. 9 to 15 of the drawings.

In FIGS. 16 to 18 of the drawings, the mold-making machine 101 according to the invention is represented in an operating position in which the match plate D is in molding position and in which the upper mold frame Ca bears with its

Claims

1. A method producing and conveying horizontally divided flaskless sand molds comprising: a. introducing a match plate between two mold frames and dies of a mold-making machine actuatable in a substantially vertical direction; b. lowering the upper mold frame and raising the lower mold frame to abut against said match plate and thereby forming mold cavities on each side of said match plate; c. pneumatically feeding molding sand into said mold cavities; d. compressing said molding sand against said match plate by moving said dies relative said mold frames; e. raising and lowering said upper mold frame and die and said lower mold frame and die respectively to free said match plate; f. moving said match plate from said mold-making machine to a rest position which is laterally adjacent thereto; g. moving at least one die relative to its mold frame to close said mold, the closed mold resting on said bottom die which is substantially flush with the upper edge of said lower mold frame; h. returning said match plate from its rest position to said mold-making machine to laterally eject the finished closed mold and start another molding cycle; i. supporting said finished closed mold on at least two sides by supporting means, said supported finished closed mold adapted to bear against previously made molds to form a mold train.

2. A method as claimed in claim 1 wherein said mold train is moved on conveying means in the direction of a casting pit.

3. A method as claimed in claim 2 wherein said conveying means is a horizontal conveyor track, the sole motive force for said mold train being that of the returning match plate which ejects said finished mold and thereby moves said mold train one mold length.

4. A method as claimed in claim 3 wherein the adjacent finished molds in the mold train have their lateral sides supported by said supporting means, the adjacent sides mutually bear on each other.

5. A method as claimed in claim 2 wherein said conveying means is a driven conveyor track, and the driving power is derived from the same power source as the driving power for said match plate movement.

6. A method as claimed in claim 2 wherein said supporting means support the lateral sides of said finished molds in said mold train and adjacent supporting means bear on one another to prevent undue pressure from being exerted on the mutually adjacent mold sides in said mold train, and the power source for the movement of said match plate and the movement of said mold train are the same.

7. A method as claimed in claim 6 wherein separate power sources actuate said match plate and said mold train.

8. A method as claimed in claim 1 comprising the further step of changing the patterns on said match plate during the period said match plate is in said rest position without interrupting the molding cycle.

9. A method as claimed in claim 1 comprising the further step of heating said match plate while it is in said rest position by an external to the plate source.

10. A method as claimed in claim 1 wherein said pneumatic feeding of molding sand to said upper and lower mold cavities is carried out in a substantially vertical direction.

11. A method as claimed in claim 10 wherein said feeding to the upper and lower mold cavities is done simultaneously.

12. A method as claimed in claim 1 comprising the further steps of evacuating said match plate during the feeding of said molding sand to augment such feeding into said mold cavities, and pressurizing said match plate during the raising and lowering of said mold frames and dies to augment freeing said finished mold from said match plate.