US3241199A - Method of packing by squeezing of the foundry molds - Google Patents

Description

March 22, 1966 B. v. RABINOVECH 3,241,199

METHOD OF PACKING BY SQUEEZING OF THE FOUNDRY MOLDS Filed Aug. 28, 1964 3 Sheets-Sheet l 0 N m w h/ u a Qg 1 www L4 INVENTOR x9. 1/. ffla/A/owcv-l March 22, 1966 B. v. RABINOVICH 3,241,199

METHOD OF PACKING BY SQUEEZING OF THE FOUNDRY MOLDS Filed Aug. 28, 1964 3 Sheets-Sheet 2 5w. $1 5 2. L Fri 5-; T x

w; 2 INVENTOR A 23. 1/. 245mm V/CH March 22, 1966 B. v. RABINOVICH 3,241,199

METHOD OF PACKING BY SQUEEZING OF THE FOUNDRY MOLDS Filed Aug. 28, 1964 3 Sheets-Sheet 3 4 ,ZW 7b.

United States Patent 3,241,199 METHOD OF PACKING BY SQUEEZING OF THE FOUNDRY MOLDS Benedict Veniaminovich Rabinovich, Yauzsky Blvd. 14, Apt. 16, Moscow, U.S.S.R. Filed Aug. 28, 1964, Ser. No. 392,724 6 Claims. (Cl. 22-193) This is a continuation-in-part of my copending application Serial No. 168,594 filed January 22, 1962, now abandoned.

This invention relates to foundry practices and more particularly to a method of making a casting mold component which may be a cope or drag or both, by utilizing a preliminary pattern to partially compact a molding material such as sand, and a final pattern to further compact the molding material and provide the final mold component.

Heretofore numerous attempts have been made to improve the quality of casting mold components and these attempts have involved the use of rubber diaphragms or squeeze plates having projections thereon and also the use of a flowable molding mixture, but many of these prior art methods are time-consuming and costly, and furthermore have not resulted in providing mold components of the desired quality.

It is accordingly an object of the present invention to provide a method of making a casting mold component which may be rapidly carried out and which results in providing a mold component of superior quality.

A further object of the invention is the provision of a method of making a casting mold component in which there is achieved a regulated and uniform packing of the sand or other molding material during the molding operation, and the notation regulated packing has reference to a possibility for gaining the desired packing in the desired places.

A still further object of the invention is the provision of a method of making a casting mold component which operates to provide such components of superior quality and having smooth casting contacting surfaces and in which the cost of molding is materially reduced by eliminating the necessity of discarding imperfect mold components.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sectional view showing a two-component mold formed by utilizing the method of the invention, and in which the drag is convex and the cope concave;

FIG. 2 is a sectional view showing a stack mold consisting of three components constructed in accordance with the method of this invention;

FIGS. 3a to 30 sectional views showing the steps of the method utilized in forming one concave component of a mold;

FIGS. 4a to 40 sectional views showing a modified method of making a mold component;

FIGS. 5a to Sc sectional views showing the steps in a method of making a convex mold component;

FIGS. 6; to 60 sectional views showing the steps in a method of making a double mold component having one side convex and the opposite side concave; and

FIGS. 7a to 70 sectional views showing the steps in the method of making a double mold component in which the molding material is blown into the flask and with the resulting component having one side concave and the opposite side convex.

In connection with the drawings, the following is indicated thereon:

Z denotes the height of the layer in the finished mold.

3,241,199 Patented Mar. 22, 1966 A denotes the height of the additional layer compacted under pressure.

The index i in the mathematical expressions set forth below indicates the appropriate vertical section of the layer of the mold. For the periphery of the mold it is assumed that i=0, i.e. Z =Z =H where H is the height of the flask; A;=A For the subsequent sections of the layers positioned above the pattern i:1,2,3

Depending upon the metal pressure taken by the mold and taking into consideration the technological requirements a required compacting is established for each column of sand. It is characterized by the value of the compression (packing) coefiicient K which is equivalent to the ratio of the height A of the additional layer of mix compacted under pressure to the height Z, of the pressed layer above the final pattern, i.e.

Determining from experience the value of K and knowing the height of the layer Z it may be ascertained from the above formula that A =K Z As a rule, K, lies within the range 0.30.8. In the particular case the mold may be compacted uniformly, therefore all coefiicients K, have a similar value, namely,

With particular reference to FIG. So, there is shown a conventional flask 5 mounted on frame 1 of a conventional molding machine, and a preliminary pattern 3 is positioned on a pressure plate 4 and a stripper plate 2 is disposed around the pattern 3 in contact with the upper surface of the pressure plate 4. The preliminary pattern 3 is partially inserted into the flask 5 and it is to be noted that the upper surface of the stripper plate 2 is disposed a distance A below the lower edge of the flask 5, and it is to be noted that A. is equal to K H and reference is made to the formula discussed above.

ment of the sand.

The pressure plate 4 together with the stripper plate 2 and preliminary pattern 3 is moved upwardly a predetermined distance to partially compact the sand in the flask 5, which results in forming a preliminary mold cavity in the sand which is shown in full lines in FIG. 3b. Thereafter, the stripper plate 2 is retained in position while the pressure plate 4 and preliminary pattern 3 are removed and a final pattern 7 is substituted for the preliminary pattern 3. With the final pattern 7 disposed on the pressure plate 8, such pressure plate and final pattern 7 are moved upwardly until. the upper surface of the stnipper plate 2 is in alignment with the lower edge of the flask 5 as shown in FIG. 3c. This results in further compacting the sand in the flask 5 and provides the final mold cavity.

The heights X X X of the preliminary pattern are calculated in accordance with the heights h I1 11, of the final pattern and are obtained from the general formula X =H (K K +h (1+K When applying this formula, the fact must be taken into consideration that heights X and h are counted off upwardly of the surface of the stripper plate 2 and such heights are viewed to be positive when the pattern is a convex pattern. Otherwise, when the heights X and h;

are counted off downwardly, these values are considered to be negative if the pattern is a concave pattern.

In a particular case for uniform mold packing When K =K =K =K :idem=K, then the formula assumes X =h (1+K).

If desired, the method described above in connection with FIGS. 3a to 3c could be carried out on a rollover type of molding machine in which the flask is inverted during the molding operation, and in such case use of the stripper plate 2 is not necessary.

Example N0. 1

It is assumed that the height of the flask 5 and the layer along the mold periphery, H =Z =200 mm. (FIG. 3a), and the heights of the pattern h =l20 1pm., h =40 mm. (FIG. 30). According to technological consideration, the layer arranged along the mold periphery, of Z thickness, must be highly packed while the layer of Z thickness is a little weaker and the layer of Z thickness is the weakest.

To effect a certain result in accordance with practical data, it is necessary to assume the following values of packing coeflicient for the corresponding layers:

K 08; K 06; K :0.7

The following should be calculated:

(a) Depth A .In FIG. 3a where it is sought to lower the upper surface of the stripper plate relative to the lower edge of the flask 5, the same is calculated on the basis of the formula namely A =K -Z =0.8 -200: 160 mm.

(b) Heights of the preliminary pattern X X .-The above is calculated on the basis of the formula namely 1 O( O 1) +/11(1+K1)= 200(O.8-0.6)+120(1+0.6)=232 mm.

In FIGS. 4a to 40 there is shown a modified method of making a casting mold component in which preliminary pattern 9 is inserted in the flask 5 from the bottom and is moved upwardly by movement of the pressure plate 4- and stripper plate 2 to partially compact the sand in the flask 5, the platen 6 serving to prevent upward movement of the sand, and this operation serves to initially compact the sand.

Thereafter, as shown in FIG. 4b, the preliminary pattern 9 is removed but pressure plate 11 and stripper plate 2 are positioned with the upper surface of the stripper plate 2 and pressure plate 11 in alignment with the lower edge of the flask 5 to prevent downward movement of the sand in the flask, and the final pattern 7 is moved downwardly into the sand to further compact the same and provide the final mold cavity.

In this form of the invention the heights of the preliminary pattern 9 are indicated as Y and Y which correspond to X and X described above in connection with the first form of the invention, and the value of these heights Y and Y are obtained from the same formula X =H (K -I With particular reference to FIGS. 5a to Sc, there is shown the steps in a method for producing a convex mold component which may be either a cope or a drag, and the same formula as given above are utilized for obtaining the values of X and X which represent the heights of the preliminary pattern 3.

As shown in FIG. 5a, a flask 5 is disposed on a surface of the molding machine 1 in alignment with an opening therein in which is slidably positioned the preliminary pattern 3 which is provided with a cavity therein. Thereafter the flask 5, as well as the cavity in the preliminary pattern 3, is filled with sand and the preliminary pattern 3 is moved upwardly a predetermined distance to partially compact the sand and provide a preliminary convex mold component. Then the flask 5 and the preliminary pattern thus obtained are turned 180 by suitable means. In this position, the preliminary pattern 3 is removed and the final pattern 7 is inserted into the space arranged on the machine frame (FIG. 5b). The final pattern 7 is moved downwardly to the position shown in FIG. 5c to further compact the sand and provide the final convex mold component.

Example N 0. 2

It is assumed that the height of the flask and that of the layer along the mold periphery, H =Z =l20 mm. (FIG. 5a) and the heights of the pattern h =l00 mm., [1 :20 mm. (FIG. 5c). The values for the corresponding layers are K =0.8, K =O.6 and K =0.7.

It is then necessary to determine the following:

(a) Dimensions A .In FIG. 5a, the same is calculated in accordance with the formula namely A =K Z :O.8-=96 mm.

(b) Heights X X .The above are calculated on the basis of the formula X =H ,(K -K )+h (1+K namely and X2 H (K I(2) 1+0.7)= 22 mm.

In FIGS. 6a to 6c there is shown a method of making a double mold component having a concave portion and a convex portion, and for this purpose there may be provided a flask 5 positioned on a molding machine 1 with a pressure plate 11 disposed below the flask 5. The flask is filled with sand or other suitable molding material and after disposing a platen 6 on the upper edge of the flask 5 the pressure plate 11 is moved upwardly to partially compress the sand in the flask 5.

Thereafter the pressure plate 11 and platen 6 are removed and a final concave pattern 7 is disposed below the flask 5 while a final convex pattern 7" is disposed above the flask 5. The patterns 7' and '7" are moved toward each other to further compress the sand in the flask 5 and to provide a final mold component having a convex portion and a concave portion, as clearly shown in FIG. 6c.

The method described in connection with FIGS. 6a to 60 may be utilized to produce a mold component of the type utilized in the stack mold shown in FIG. 2.

The mold component thus produced can be used for the upper or lower component of a mold as illustrated in FIG. 1. If it is to be employed as the cope, its concave upper face will engage the metal. The projection formed against the pattern 7 can be removed or left in position. Also, the mold component could be used as the drag shown in FIG. 1 and in this situation, the projection formed on pattern 7' would engage the metal.

With particular reference to FIGS. 7a to 70, there is shown a further method of making a double mold com-- ponent having a concave portion and a convex portion, and in this form of the invention a flask 5 is positioned on the molding machine 1 and a preliminary convex pattern: 3" supported on a pressure plate 4 and a stripper plate 2 is partially inserted in the flask 5 from below and a preliminary concave pattern 3' is disposed above the flask -5.

A plate 12 on the molding machine is provided with an inlet fitting 13 which is received in an opening in the preliminary concave pattern 3' and the preliminary pattern 3' is also provided with air vent openings 14. Sand or other molding material is blown into the flask 5 through.

the fitting 13 and air escapes from the flask through the vent openings 14. The blowing of sand into the flask 5 operates to fill the same and partially compacts the sand to provide preliminary concave and convex mold surfaces.

Thereafter the preliminary convex pattern 3" and the preliminary concave pattern 3' are removed and replaced by a final convex pattern 7" and a final concave pattern 7, which patterns are moved toward each other to the position shown in FIG. 7c which results in providing a final double mold component having concave and convex portions.

In the form of the invention shown in FIGS. 7a to 7c the height X, of the preliminary pattern is calculated from the formula X =h /2l(H K Z,K In the particular case for uniform mold packing when In applying the above formula, X, and h, are positive when the pattern is convex and negative when the pattern is concave, and it is further to be noted that the symbols utilized in the formula are indicated in FIGS. 7a to 70.

Example N0. 3

It is assumed that the height of the flask and that of the layer, H =Z =t200 mm., the heights of the concave pattern h '=100 mm., h '=20 min, and the heights of a convex pattern h 120 mm, h "=40 mm. (FIG. 7c). Then the following values of packing coeflic-ients are selected for the corresponding layers, namely K =0.8, k1=0.6 and K2=0.7.

The following is then calculated:

(a) Dimensions A .In FIG. 7a, the same are determined in accordance with the formula (c) Heights of convex preliminary pattern X and X ".-These are also calculated in accordance with the formula X =h /21(H K Z K i.e.

It will be seen that by the above-described invention there has been provided various modifications of .a method of making a casting mold component which will result in producing such a mold component having superior characteristics, and this method results in reducing the cost of foundary procedures by reason of elimination of the necessity for frequently discarding mold components of inferior quality.

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof, and therefore the invention is not limited to that which is shown in the 6 drawings and described in the specification but only as indicated in the appended claims.

What is claimed is:

1. A method of making a casting mold component utilizing a flask, molding sand or the like, a platen, a pressure plate, a stripper plate, a preliminary pattern and a final pattern, said method comprising the steps of disposing said preliminary pattern and stripper plate on said pressure plate, placing the flask above the pattern and stripper plate, partially inserting said preliminary pattern into said flask from below, filling said flask with sand, disposing said platen on the upper side of said flask to prevent upward movement of the sand, moving said pressure plate, said stripper plate and said preliminary pattern upwardly a predetermined distance to compact the sand and provide a preliminary mold cavity, retaining said stripper plate in position and removing said pressure plate and preliminary pattern, disposing said final pattern on said pressure plate, inserting said final pattern into said preliminary mold cavity, moving said pressure plate, said stripper plate and said final pattern upwardly until the upper surface of said stripper plate is in alignment with the lower edge of said flask to further compact said sand and provide a final mold cavity and removing said platen, said pressure plate, said stripper plate and said final pattern to provide said mold component.

2. A method of making a casting mold component utilizing a flask, molding sand or the like, a platen, a pressure plate, a stripper plate, a preliminary pattern and a final pattern, said method comprising the steps of disposing said preliminary pattern and stripper plate on said pressure plate, placing the flask above the pattern and stripper plate, partially inserting said preliminary pattern into said flask from below, filling said flask with said, disposing said platen on the upper side of said flask to prevent upward movement of the sand, moving said pressure plate, said stripper plate and said preliminary pattern upwardly a predetermined distance to compact the sand, retaining said stripper plate in position and removing said pressure plate and preliminary pattern, replacing said pressure plate in engagement with said stripper plate, removing said platen, forcing said final pattern downwardly into the sand from the side opposite said stripper plate and pressure plate to provide a final mold cavity and removing said pressure plate, said stripper plate and said final pattern to provide said mold component.

3. A method of making a convex casting mold component utilizing a flask, a molding machine having an opening to slidably receive a pattern, a preliminary concave pattern and a final concave pattern, said method comprising the steps of disposing said flask on said mold ing machine in alignment with said opening, disposing said preliminary pattern in said opening below said flask, filling said flask with sand, moving said preliminary pattern upwardly to partially compact said sand and provide a preliminary convex mold component, removing said preliminary pattern, inverting said flask and preliminary mold component and disposing the same on said machine below said opening, disposing said final pattern in said opening, moving said final pattern downwardly to further compact said sand and provide a final convex mold component, removing said final pattern and removing said flask and final mold component from said machine.

4. A method of making a mold component having a concave impression on one side and a convex impression on the other side utilizing a flask, a platen, a pressure plate, a concave pattern and a convex pattern, said method comprising the steps of disposing said pressure plate below said flask, filling said flask with sand, disposing said platen in engagement with the upper edge of said flask to prevent upward movement of said sand, moving said pressure plate upwardly a predetermined distance to partially compact said sand, replacing said pressure plate by said concave pattern, replacing said platen by said convex pattern, moving said patterns toward each other to form a convex mold element at the bottom of said flask and a concave mold element at the top of said flask and removing said patterns to provide a mold component having a concave impression on one side and a convex impression on the other side.

5. A method of making a mold component having a concave impression on one side and a convex impression on the other side utilizing a flask, a concave preliminary pattern having sand inlet and air outlet openings, a preliminary convex pattern, a stripper plate, a pressure plate, a final concave pattern and a final convex pattern, said method comprising the steps of disposing said concave preliminary pattern above said flask, disposing said convex preliminary pattern and stripper plate on said pressure plate and partially inserting said convex preliminary pattern into said flask from below, blowing sand into said flask through said inlet opening to fill said flask and partially compact the sand, retaining said stripper plate in place and removing said preliminary patterns, substituting said final patterns for said preliminary patterns, moving said final patterns toward each other to further compact said sand and provide a convex mold element at the top of said flask and a concave mold element at the bottom of said flask and removing said patterns and stripper plate to provide a mold component having a concave impression on one side and a convex impression on the other side.

6. A method of making a casting mold component utilizing a flask, a preliminary pattern and a final pattern, said method comprising the steps of partially inserting said preliminary pattern into said flask, filling said flask With sand, moving said preliminary pattern through a predetermined distance to partially compact said sand and provide a preliminary mold element, substituting said final pattern for said preliminary pattern, moving said final pattern to further compact said sand and provide a final mold element and removing said final pattern to provide said mold component.

References Cited by the Examiner UNITED STATES PATENTS 705,215 7/1902 Davis 2250 2,791,013 5/1957 Dernmler 2236 2,839,799 6/1958 Herbruggen 2236 2,908,950 10/1959 Mutter et a1 2236 MARCUS U. LYONS, Primary Examineer.

Claims (1)

1. A METHOD OF MAKING A CASTIN MOLD COMPONENT UTILIZING A FLASK, MOLDING SAND OR THE LIKE, A PLATEN, A PRESSURE PLATE, A STRIPPER PLATE, A PRELIMINARY PATTERN AND A FINAL PATTERN, SAID METHOD COMPRISING THE STEPS OF DISPOSING SAID PRELIMINARY PATTERN AND STRIPPER PLATE ON SAID PRESSURE PLATE, PLACING THE FLASK ABOVE THE PATTERN AND STRIPPER PLATE, PARTIALLY INSERTING SAID PRELIMINARY PATTERN INTO SAID FLASK FROM BELOW, FILLING SAID FLASK WITH SAND, DISPOSING SAID PLATEN ON THE UPPER SIDE OF SAID FLASK TO PREVENT UPWARD MOVEMENT OF THE SAND, MOVING SAID PRESSURE PLATE, SAID STRIPPER PLATE AND SAID PRELIMINARY PATTERN UPWARDLY A PREDETERMINED DISTANCE TO COMPACT THE SAND AND PROVIDE A PRELIMINARY MOLD CAVITY, RETAINING SAID STRIPPER PLATE IN POSITION AND REMOVING SAID PRESSURE PLATE AND PRELIMINARY PATTERN, DISPOSING SAID FINAL PATTERN

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