US2685112A - Machine for making foundry molds - Google Patents

Description

Aug. 3, 1954 R. G. MARILLIER 2,685,112

MACHINE FOR MAKING FOUNDRY MOLDS Filed Dec. 18, 1951 3 Sheets-Sheet l 1 I Z0 '26 I 2 I g o .9 \35 Z] 0 2 if I ATTORNEYS Aug. 3, 1954 Filed Dec. 18 1951 R. s. MARlLLlER 2,685,112

MACHINE FOR MAKING FOUNDRY MOLDS 5 Sheets-Sheet 2 ATTORNEYS Patented Aug. 3, 1954 UNITED STATES ATENT OFFICE France, assignor to Etablissements A. Marillier, Saint-Loup-sur-Semouse, France, a society of France Application December 18, 1951,

Serial No. 262,214

Claims priority, application France December 23, 1950 4 Claims.

packing plate.

Other features of my invention will become apparent in the course of the following detailed description of some specific embodiments thereof with reference to the accompanying drawings, by way of example, and in which:

Figs. 1 and 2 are diagrammatical views showing, respectively in elevation (partly in section) and in plan view, a machine for making foundry molds according to my invention.

Fig. 3 shows, on a larger scale and in longitudinal section on the line IIIIII of Fig. 4, the control means for moving the table of the machine upwardly and downwardly.

Fig. 4 is a bottom view of the power piston included in the means of Fig. 3.

Fig. 5 shows, in axial section, a modification of the means for temporarily connecting the lower part of the power piston with the hammer.

Figs. 6 and 7 are views similar to Fig. 4 showing the elements of the mechanism in different relative positions.

The machine as a whole is of conventional construction. In the example shown, it includes a support I carrying a fixed cylinder 2 in which is housed the mechanism for controlling table remove the molds, arm well known, through 1 into the position shown 2, to facilitate access to to make it possible to 5 may be pivoted, as about a vertical spindle in dotted lines in Fig. table 3.

Frame I also carries, on one of its side walls, an oblique arm 8 the free end of which supports a valve system 9, controlled by means of a handle 50, for feeding a fluid (air) under pressure to move table 3 up and down.

A frame 5! is guided at every corner of table 3 by a vertical rod. This frame can be moved up and down by means of two vertical cylinders ii in which pistons I2 are slidable. In order to obtain a vertical and perfectly plane movement of the frame, this frame is stiffened by plates l3. Through distributing valve 9 and orifices 56, fluid is fed to the chambers 55 at the lower part of cylinders H, which causes the whole of pistons l2, frame 57 and the guiding rods to move vertically in the upward direction. Due to this vertical movement, the molding box is moved away from the pattern plate placed on table 3, until the molded piece is cleared and can be removed from the table.

When the molding box is removed, fluid is caused, by means of distributing valve 9, to escape from chambers 55 and the whole structure is returned to its initial position. A new molding box is then placed on the pattern plate.

The molding box is filled with the molding material (sand) and the packing plate 55 is brought back, by rotation of arm 5 through 90, above the table for the making of another mold.

All the parts above described are well known in the art and are not essential elements of the structure according to my invention, which is concerned with the means for controlling the upward and downward movement of the table and the operation of the hammer.

According to my invention, the molding box placed on table 3 and filled with sand or any other molding material is to be subjected to at least one shock before table 3 is moved upwardly toward plate 5 and is subjected to vibrations by the action of the hammer.

For this purpose, I provide in the fixed vertical cylinder 2 a piston made of two parts l4 and coaxial and located one above the other. The upper piston element l4, upon which rests table 3, which is fiXed thereto, includes, at the top thereof, a flange 56 adapted to rest on the upper edge of cylinder 2 and when flange I6 is resting on the top end of cylinder 2 and the lower piston i5 is in contact with the bottom of this cylinder, there is a space ll (Fig. 3) between these piston elements. This space is in communication, through a conduit l8, with distributing valve 3 so as to be fed with a fluid under pressure, in particular compressed air, when said distribution valve is placed in the corresponding position.

When the lower piston element I5 is resting upon the bottom l9 of cylinder 2, the compressed air admitted into space H moves the upper piston element i4 and table 3 upwardly until the lower edge 20 of this last mentioned piston element comes to the level of the exhaust orifice or orifices 2! provided in the wall of cylinder 2 and opening to the atmosphere, so that this compressed air escapes suddenly into the atmosphere. As, in the meantime, the feed of compressed air to space H has been cut off, there is a sudden drop of the pressure under piston element It, which moves down suddenly under the effect of its weight until the flange l6 thereof strikes the upper edge of cylinder 2. A shock is thus imparted to the molding box carried by table 3,

which thus produces an even distribution and a settling of the sand in all the cavities of the pattern, more especially in the angular portions thereof.

If necessary, this operation is repeated as many times as wanted, by suitably operating distributing valve 9.

The upper piston element M which, as above described, serves to impart at least one shock to table 3 and the molding box placed thereon, prior to its upward movement for cooperation with packing plate 3, and the lower piston element l5, which has remained inactive up to this time, both cooperate in producing the successive upward and downward movements of the table,

these two piston elements being provided with housings for the hammer which is to strike the under face of table 3 in a vibratory manner when the molding box is in contact with the packing plate 6.

For this purpose, I provide in the upper piston element H! a bore 53 coaxial with said piston element outer wall and a cylindrical hammer 22 is housed slidably in this bore. This hammer 22 extends downwardly beyond the lower end of piston element 14 and the lower end of this hammer 22 is also slidably engaged in a corresponding cylindrical bore 23.

During the operation of the upper piston element H! in order to impart shocks to the molding frame placed upon table 3, as above described, hammer 22 should preferably not participate in the movements of this piston element i4 and should therefore be temporarily held stationary by the lower piston element, which does not move at this time. This may be done, as shown by Figs. 3, 6 and '7, by means of balls 24 movable in passages 25 including each two portions at right angles to each other. These passages 25 are distributed at regular intervals along the circumference of piston element 15. Each of them includes a portion making a small angle with the vertical axis of the piston and which opens into the upper edge thereof and a portion making a small angle with a horizontal plane and which opens into the cylindrical wall of said piston ele- Oil ment, opposite a circular groove 26 formed in hammer 22, when said hammer is in its lower position. When compressed air is introduced into space I1, this air automatically pushes back the balls present in passages into groove 26, thus locking hammer 23 in its lowermost position, as shown by Fig. 3.

On the contrary, when the feed of compressed air to space H is cut off or when this space has been reduced to nothing by relative movement of the two piston elements I4 and I5, ball 25 automatically drops back under the effect of its weight into contact with an adjustable abut-ment 21 (Figs. 6 and '7) The hammer is then released and can be operated as it will be hereinafter explained.

This temporary holding of hammer 22 may also be obtained as shown by Fig. 5, where the bore 23a of the lower piston element 15 is of a diameter larger than that of the body of hammer 22. The lower end portion 28 of this hammer is made of a diameter fitting with that of said bore 23a. Thus, the hammer is held in lowered position by the pressure existing in space I! and transmitted to the upper edge of said enlarged portion 28 through the space 29 between the wall of the piston bore and the wall of the body of hammer 22.

The lower piston element 15 rests freely upon the bottom [9 of cylinder 2 through circular rings 30 made of an elastic material, which act as shock absorbers. Piston element I5 is provided, at diametrally opposed points, with two longitudinal channels 3| which extend throughout the piston element. In each of these channels 3| there is mounted a check valve 32 carrying a small perforated disc 33. Each valve 32 is applied upon its seat 34 by the pressure of the compressed air admitted into space H and transmitted through the corresponding channel 3|, so that this air cannot penetrate under the lower piston element l5.

On the contrary, when distributing valve 9 is adjusted to enable compressed air to penetrate through conduit 35 under the lower piston element, the feed of air into space H being of course out off at this time, piston I5 is caused to move upwardly until it comes into contact with the upper piston element M (Fig. 6) so that space I! no longer exists.

Valves 32 then open, which enables compressed air to pass through channels 3| into longitudinal passages 33 provided is piston element M at points diametrally opposed to each other. These passages 36 lead to holes 31 opening into the internal wall of said piston element 14 opposite a circular groove 38 provided in hammer 22 (Fig. 6). This groove 38 communicates through radial passages 39 with an axial conduit 40 provided in hammer 22, this conduit opening, at the lower end of this hammer into a recess 4| provided at the bottom of bore 23.

The compressed air admitted under the hammer pushes it upwardly from the position shown by Fig. 6 to that shown by Fig. '7 in which the hammer strikes the underface of table 3, this shock being transmitted to the molding box and its contents.

The inflow of air through holes 31 is cut off by the hammer itself when groove 38 moves beyond these holes. But the living force imparted to the hammer causes it to keep moving upwardly until it strikes table 3 (Fig. '7). The

7 air located above the hammer can escape through communicates through radial passages 44 with the axial channel 48 of said hammer is placed in communication through holes 45 with longitudinal channels 46 which enable the compressed air escape to the outside. For this purpose, channels 46 communicate through holes 4! with an annular chamber 48 provided in the intermediate portion of piston element M. This chamber is constantly in communication with exhaust holes 49 and 49d provided in the wail of cylinder mosphere Whatever be the position occupied by the lower end portion of piston element i4.

When, due to this exhaust, there is no longer a pressure above atmospheric pressure in chamber ing movements of hammer 22 are maintained, as above stated, while the piston units M45 is moving upwardly until shoulder 50, formed at the lower part of piston element M, comes into upper limit position.

When the machine operator judges that the sand contained in the molding box has been packed suificiently between table 3 and plate 6 1' (this sand being subjected during this time to the vibrating action exerted by the hammer), he places valve 9 in the position which cuts 01f the feed of compressed air.

Once the sand has been packed, the air present 5 under piston element It escapes through conduit 35 and distributing valve 9 which now occupies the position for which this conduit is in communication with the atmosphere. The lower piston element i5 and hammer 22 move down shown by Fig. 3. The shock at the end of this downward movement is absorbed by elastic ring elements 30. The upper piston element also moves down until its top flange 98 comes to rest upon the upper edge of guiding ring 5!.

Table 3 and the moulding box supported thereon move down together with piston element 55.

The operator then turns arm 5 and packing plate 5 into the position shown in dotted lines in Fig. 2, which clears the top of table 3. He then starts the well known vibrating device (not shown) generally located at 52 (Fig. 1) to facilitate the removing of the molded article from the molding box. This operation is effected by placing valve 9 in the corresponding position, as briefly described above.

The machine is now ready for a new cycle of operations.

The movement of piston elements M and I5 to- Ward each other is not necessarily obtained through pneumatic means but might be achieved through hydraulic, mechanical or electrical means.

Piston elements might be disposed one about the other, one of them serving to produce the shocks as done by piston element M in the concombination with the vibrating shocks produced by the hammer. The two piston elements would then be driven through pneumatic, hydraulic or mechanical means.

In a general manner, while I have, in the prehended within the scope of the accompanying claims.

What I claim is:

1. A machine for making foundry molds which comprises, in combination, a fixed support, a vertical cylinder carried by said support, a packunder pressure fed to said chamber, whereby the feed of said last mentioned fluid under pressure communication with said axial bore, and said drical bore provided in the second mentioned piston element being of a diameter fitting with that of said lower end of the hammer and the cylinder and said first piston being provided top of the last mentioned cylindrical bore openwith exhaust passages for connecting with the ing into said space between the two piston eleatmosphere the last mentioned groove in the ments, whereby said hammer in urged downhammer when said hammer has moved a given wardly by the pressure ex ting in said space distance upwardly under the effect of the fluid when fluid under pressure is fed thereto.

under pressure fed through said channels and said hammer being provided with another groove located under the last mentioned one and in 4. A machine according to claim 1 including, said bore. in the longitudinal channel provided in the sec- 2. A machine according to claim 1 in which 0nd piston element, a check valve opening upthe lower part of the cylindrical wall of said wardly for connecting said chamber with said hammer is provided with a circular groove, said channels. second mentioned piston element being provided with passages each of which opens at one end into said space between the two piston elements and at the other end into the cylindrical wall References Cited in the file of this patent UNITED STATES PATENTS of the bore in said second mentioned piston elei g sz 3 2:? Z ment opposite said groove in said hammer, and 1605096 Campbell 1926 balls in said passages adapted to engage in said 41 Roncemy 1952 groove for holding the hammer with respect to the second mentioned piston element. FOREIGN PATENTS 3. A machin according to claim 1 in which Number Country Date the lower end of said hammer is of a diameter 438,394 Great Britain 15 1935 larger than the remainder thereof, the cylin-

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