US2904858A

US2904858A - Production of moulds for metal casting

Info

Publication number: US2904858A
Application number: US651316A
Authority: US
Inventors: Pinchon Michel Philipp Auguste
Original assignee: FOND CHOKIER SA
Current assignee: FOND CHOKIER SA; FONDERIES CHOKIER SA
Priority date: 1956-04-13
Filing date: 1957-04-08
Publication date: 1959-09-22
Anticipated expiration: 1976-09-22
Also published as: FR1147675A; GB858899A; BE556502A

Description

Sept. 22, 1959 M. P. A. PINCHON 2,904,858 I PR LDS FOR METAL CASTING Filed April 8, 1957 2 Sheets-Sheet 1 FIG.

BY I

Maul S. MM

Sept. 22, 1959 AQPINCHQN 2,904,858

PRODUCTION OF MOULDS FOR METAL CASTING Filed April 8, 1957 2 Sheets-Sheet 2 Wino. s. 5M0.

United States Patent PRODUCTION DF'MOULDSFOR IVIETAL CASTING Michel Philippe Auguste P inc hon, Hautmont, France, .assignor to Soc'it Anonyme Fonderies Chokier, Nerd, "France, a com an of France Applicati0n April 8, 1957, Serial No. 651,316 Claims priorit application France April 13, 1956 7 Claims. '01. -22-'20) I This invention relates to a process and an apparatus for the series'producti'on of sand moulds for'rnetal cast- In the process according to the present invention, the sand is pressed on a pattern plate inside a moulding box carried by'a manipulating arm, the arm being adapted to pivot about a vertical axis. The compacted box is then carried by the arm from the place where the box was filled to a conveyor on to which it is lowered. The "conveyor moving in intermittent steps carries the mould to an appropriate position for casting.

The objects of the invention are twofold.

Qne object is to provide a process in which'the metal can be cast into the sandmould after it has been'removed from the moulding box in which it was rammed. In such a case the moulding box can be connected rigidly to the manipulating arm or may be such that it can only be disconnected from it with difficulty. The moulding box is separated from the mould proper by vertically displacing the box while holding the mould on the conveyor by means of a press. The conveyor carries the mould thus formed to the casting position. It is sometimes desir able to support the mould in an auxiliary box during the actual casting.

A further object of the invention is to provide an in stallation or carrying into effect the process. Such an installation comprises essentially at least one moulding pressforpressing the sand onto a pattern within a moulding box, atleast one substantially horizontal manipulating arm carrying the box at one 'end and which is mounted at the other end on a vertically telescopic pivot and is adapted to rotate about a vertical axis through the pivot and a conveyor adapted to receive the mould from the manipulating arm and to carry it step by step to the casting position.

A still further object is to provide apparatus for removing the sand mould proper from the moulding box, when the box is not to be separated from the manipulating arm. The installation then also comprises a stripping press, situated above the place Where the manipulating arm deposits the mould on the conveyor. The press holds the mould proper on the conveyor and the manipulating arm --moves'vertica'lly carrying the moulding box with it.

A further object is to provide a convenient means for supporting the sand mould during casting after'it has been removed from its original moulding box. It com- =prises carrying the mould on the conveyor below an endless chain having depending from it auxiliary boxes. The belt 'is arranged so that the boxes have a descending run for the purpose of gradually covering each mould with a box while it is being transported along the conv'eyor, a horizontal run, whose length is determined by the speed of the conveyor and on the time required for the operations of casting and cooling the metal, an 'as- (Sending run for progressively separating the mould containing the castrn'e'tal from the auxiliary box, and a return runwhich is offset relatively to the three preceding 2,904,858 Patented Sept. 22, 1959 runs and'connects the ascending run to the descending run.

An example of an installation according t o the invention will now be described with reference to the accompanying drawings in which: I v I I v Figure l is a perspective View of part of an installation.

Figure 2 is a side view of the said installation taken parallel to the axis of the conveyor.

Figure 3 is a sectional View of the moulding press. I, Figures 4 is a sectional view of the manipulating of the installation and the pivot of the said arm.

The installation illustrated is composed of t w om'o u lding presses, tWo manipulating arms, a block-removing press, a conveyor, an endless chain carrying "the auxiliary boxes, and'acasting apparatus which is not shown.

Each moulding press comprises a frame '1, a support 2for a pattern plate, a pressure head 3 fixed to the upper part of the frame above the patter-n plate, a sand reser: voir 4 arranged rearwardly of the pattern plate, a'slide 5 with sand supply control device ",6 and closure members 7 mounted on the slideways at the level of the lower portion of the sand reservoir. Slide 5 is horizontally reciprocable by means of hydraulic actuator '5.

Each manipulating arm is composedof an arm 9 which ispivotable through 180 about a pivot it and a moulding box 8 is fixed to and forms an integral part of each arm 9. The pivot itself is moved in upward and downward direction by a jack 10h.

The manipulating arm of the lower part of the mouldingbox also allows the box to be turned upside down. Preferably thehoriz ontal rotational movement of the arm is divided into two movements of 90 each so that the mould may be inspected after compression and before being deposited on the conveyor. The horizontal rotation of the arm is effected by a tooth'ed sector 11 'fixedto the base of said pivot which is driven by a rack 12 eontrolled by jack 13. The division of the horizontal rotational movement of the lower arm about the pivot into two movements of 90 is brought about by means of two jacks 13 each controlling a rotation of 90, or by a. single special jack which operates in two stages.'

, The turning of the box of the lower block is eifected by a toothed sector 14 fixed to the end of the manipultitihgarm shaft. As is shown in Fig. 4, the arm 9 extends transversely through the cylinder 10 and is supported for turning movement about its longitudinal axis b y suit'abl'e bearings carried by the cylinder 10. The toothed sector 14 is fixed to the left end of the arm '9, as viewed in Fig. 4, and meshes with a vertical rack one end of which is connected with the piston of a hydraulic jack supported at the side of the cylinder 10 and cornmunicating with any suitable source of fluid under pressure for moving the latter rack up and down so as to turn the arm 9 about its axis for inverting the lower or drag mold box 8. The top end of the rack which cooperates with the sector 14 is guided for axial movement by a suitable bearing fixedly carried by the cylinder 10 and shown at the top of Fig. 4.

Each box has at its end and on each side a roller 15 which serves to guide the descent onto the pattern plate and to guide the placing of the mould on the conveyor.

The block removing press or stripping press is a hydraulic jack situated above the conveyor in the axis of alignment of the two moulding boxes when they are brought together over the conveyor. The piston rod of this jack comprises at its lower portion a plate whose external dimensions are slightly less than the smallest internal dimensions of the boxes.

The. object of the stripping press is to hold the two blocks on the conveyor while the boxes are moved upwards and separated by the manipulating arms. The

pressure should be sufficient to detach the sand from the walls of the boxes but should not be so great as to risk crushing the mould.

The conveyor 17 is of a continuous rectilinear type having a plane surface. It advances intermittently, syn chronised with the movements of the pivoting arms. Each forward step is equal to about 1 /2 times the length of the blocks and takes place whilst the boxes are engaged in the presses.

The conveyor must be of such length as to perm1t casting in the blocks after they have been moulded, and a sufficiently long cooling time. The length therefore depends on the nature of the parts and the time which the machine takes to carry out a complete moulding cycle.

An endless chain 20 carries auxiliary boxes 21 which are spaced apart from one another in the horizontal sense by a distance equal to one step of the conveyor 17. The chain 20 travels over rollers 22. Its path of travel is in four separate parts and comprises a descending run 200 in which the auxiliary boxes move downwardly to surround the mould, a horizontal run 2% in which time the casting is effected and the metal cooled, an ascending run 200. in which the auxiliary boxes 21 are removed from the moulds and a return run 20a connecting the runs 20d and 29c. The return run is offset relatively to the plane of the conveyor 17 so as to return the auxiliary boxes 21 after they have been separated from moulds to the beginning of the run 20c.

An example of the method for making a two part mould is as follows:

The slides are displaced from their normal positions by the hydraulic actuators 5 so that control devices 6 move from their normal position beneath reservoir 4 to above the boxes 8. The closure members 7 are opened by the hydraulic actuators 7' which are mounted in the slides 5 so that the sand in the devices 6 fills the boxes 8 covering the pattern plates 2. The pistons 3 are moved downwards, while the devices 6 are still in position to compress the sand into the boxes 8 and on the pattern plates 2. The pistons 3 are then raised and the slides 5 are moved rearwardly. In this movement, the supply control devices 6 return to below the reservoir 4, are closed by the closure member 7 and are re-filled with sand. This displacement of the supply control devices 6 causes the upper part of the box 8 to be scraped. At the same time the pivot 10, which carries the manipulating arm carrying the box 8, is lifted, the latter carrying away the sand which it contains, whose lower face reproduces the shape of the pattern plate 2.

The pivot 10 of the box 8 of the upper part of the mould is pivoted through 180 about its vertical axis to move the box to a position above the conveyor 17. Similarly when the moulding box 8 containing the lower part of the mould is packed it is also rotated through a 180 path by the rotation of the pivot 19.

If it is required to place cores in the mould, the rotational movement of 180 on the part of the pivot may be broken down into two rotational movements of 90 each. The movement of the pivot 10 may be interrupted between the two rotational movements in order to permit the cores to be placed in position.

The two boxes 8, one corresponding to the lower part of the mould and the other to the upper part of the mould are thus positioned one above the other above the conveyor 17 and below the stripping press piston 16.

A downward movement is imparted to the pivots 10 so as to place the two blocks simultaneously on the stationary conveyor 17. At the same time the stripping press piston also moves downwardly.

The pivots 10 are raised simultaneously, while the piston 16 remains stationary. The boxes 8 separate from the moulds which they contain leaving the moulds on the still stationary conveyor 17. The block removing piston 16 then returns to its retracted position.

The pivots 10 with their boxes 8 travel again to above the pattern plates 2, executing the same movements as previously, but in the reverse sense, and the operations described hereinbefore are repeated.

During the return movement of the pivots 10 to above the pattern plates 2, the conveyor 17 moves by one step.

The blocks which have been assembled on the conveyor move below an endless chain 20 from which are suspended auxiliary boxes 21. This endless chain moves step by step each step being equal to an advancing step of the conveyor 17. The endless chain 20 passes over the rollers 22, in such manner that the upper run 20a of the endless chain 26 is in a diiferent plane from that in which the conveyor 17 is situated, whilst the runs 20c, 2% and 20d are situated in the plane of the conveyor. The

runs

20c and 20d are inclined, whilst the run 20b is horizontal. Auxiliary boxes 21 corresponding to the run 200 descend to cover progressively the assembled moulds. During the run 29b the auxiliary boxes 21 support the moulds without moving relatively thereto but during the run 20d they detach themselves progressively from the moulds.

During the travel of the moulds, corresponding to the run 20b, the metal is cast into them and allowed to cool. Thus the auxiliary boxes 21 hold the two sand moulds in position despite the pressure of the metal. In order to bring about this result, the auxiliary boxes 21 should be of an adequate weight and strength.

When the auxiliary boxes 21 have been removed from the moulds the boxes return along the run 20a to the starting point, whilst the sand moulds continue to be carried along by the conveyor 17. The moulds are broken up and the cast metal removed therefrom.

In the drawings, the conveyor 17 which is illustrated is a straight conveyor. In fact the conveyor will advantageously follow a closed loop course.

I claim:

1. In a casting apparatus, in combination, mold-forming means for making a sand mold part in a mold box located at a predetermined position on said mold-forming means; an arm; a mold box fixedly connected with said arm for movement therewith; conveyor means; moving means operatively connected with said arm for moving the same between a first location where said mold box fixed thereto is in said predetermined position on said mold-forming means to have a mold part formed therein by said mold-forming means; and a second location where said box fixed to said arm is located with the finished mold part therein over said conveyor means; and means located on said conveyor means for stripping the mold part from the box so that the mold part is conveyed by the conveyor means without the box which is fixed to said arm.

2. In a casting apparauts as recited in claim 1, said conveyor means being adapted to transport a series of sand molds without the boxes in which they were prepared, said apparatus further including second conveyor means located at least in part over said first mentioned conveyor means and operating in synchronism therewith; and a plurality of reinforcing boxes for reinforcing said molds on said first-mentioned conveyor means carried by said second conveyor means and moved thereby first downwardly around said molds on said first conveyor means, respectively, then together with said molds along the path through which they are moved by said first conveyor means, and finally upwardly away from the molds, so that said reinforcing boxes will reinforce the molds against the forces of casting material therein while the molds are transported by said first conveyor means.

3. In a casting apparatus, in combination, elongated substantially horizontal conveyor means; a pair of moldpreparing means for respectively preparing upper and lower sand mold parts respectively located at opposite sides of said conveyor means; a pair of carriers respectively located at opposite sides of said conveyor means between the latter and said pair of mold-preparing means; moving means connected operatively with each carrier for moving the same upwardly and downwardly along a vertical axis and for turning the same around said axis; a pair of substantially horizontal arms respectively carried by said pair of carriers and a pair of upper and lower mold boxes respectively fixed to said arms for movement at all times therewith, said moving means actuating said carriers to locate said boxes first respectively at said pair of mold-preparing means, to have upper and lower mold parts respectively formed therein, and then one above the other over said conveyor means to locate the upper mold part over the lower mold part on said conveyor means; and means located over said conveyor means for holding the mold parts thereon while said moving means moves said arms and boxes therewith upwardly away from the mold parts to strip the boxes therefrom so that the conveyor means then conveys the mold without the boxes in which it was formed.

4. In a casting apparatus, in combination, elongated substantially horizontal conveyor means; a pair of moldpreparing means for respectively preparing upper and lower sand mold parts respectively located at opposite sides of said conveyor means; a pair of carriers respectively located at opposite sides of said conveyor means between the latter and said pair of mold-preparing means; moving means connected operatively with each carrier for moving the same upwardly and downwardly along a vertical axis and for turning the same around said axis; a pair of substantially horizontal arms respectively carried by said pair of carriers and a pair of upper and lower mold boxes respectively fixed to said arms for movement at all times therewith, said moving means actuating said carriers to locate said boxes first respectively at said pair of mold-preparing means, to have upper and lower mold parts respectively formed therein, and then one above the other over said conveyor means to locate the upper mold part over the lower mold part on said conveyor means; means located over said conveyor means for holding the mold parts thereon while said moving means moves said arms and boxes therewith upwardly away from the mold parts to strip the boxes therefrom so that the conveyor means then conveys the mold with out the boxes in which it was formed; and reinforcing means cooperating with said conveyor means for reinforcing the mold thereon while casting material is located therein.

5. In an apparatus as recited in claim 3, each of said mold-preparing means including a stationary pattern table on which each mold part is formed in its box, and a compacting ram located over said table for compacting the sand in the box on the table.

6. In an apparatus as recited in claim 3, said means located over said conveyor means for holding the sand mold parts thereon being carried by a support which extends between and is carried by said pair of mold-forming means.

7. In an apparatus as recited in claim 5, each of said mold-preparing means further including sand storage means, and transfer means for transferring a measured amount of sand from said storage means to said box.

References Cited in the file of this patent UNITED STATES PATENTS 1,119,680 Brown Dec. 1, 1914 1,134,398 McCarte Apr. 6, 1915 1,752,175 Harmes Mar. 25, 1930 1,877,494 Bullock Sept. 13, 1932 2,325,501 Gedris July 27, 1943 2,575,123 Pollard et a1 Nov. 13, 1951 2,792,603 Anderson May 21, 1957 FOREIGN PATENTS 470,863 Germany Feb. 1, 1929 678,070 Great Britain Aug. 27, 1952