US2691804A

US2691804A - Apparatus for bottom casting

Info

Publication number: US2691804A
Application number: US276726A
Authority: US
Inventors: Lucien Rene; Tetart Emile
Original assignee: Societe dInventions Aeronautiques et Mechaniques SIAM SA
Current assignee: Societe dInventions Aeronautiques et Mechaniques SIAM SA
Priority date: 1951-01-04
Filing date: 1952-02-28
Publication date: 1954-10-19
Anticipated expiration: 1971-10-19

Description

Oct 19, 1954 R. LUClEN ETAL l 2,691,804'

` APPARATUS FOR BOTTOM CASTING Original Filed Jan. 4, 1951 fyi vPatented Oct. 19, 1954 NT QFFICE 2,691,804 AEPARA'EUS FOR BOTTOM CASTIN Ren Lucien, Paris, and Emile Tetart, Louvie- .luzon, France, assignors to Societe dnventions Aeronautiques et Mecaniques S. I. A. M., Geneva, Switzerland, a corporation of Switzerland @riginal application January li, 1951, Serial No.

2614,318. Divided and this application February 28, 1952, Serial No. 276,726

Claims priority, application France May 2, 1950 2 Claims. l

The invention relates to a process of casting which is known in metallurgy under the name of bottom casting, according to which the metal enters the mould from the lower part thereof and then slowly rises therein and carries before it any gases and impurities.

In the accompanying drawings:

Fig. 1 is a diagrammatic cross-sectional View through conventional apparatus for bottom casting;

Fig. 2 is a perspective view of apparatus for l carrying out the invention; and n Fig. 3 is a cross-sectional View throfg'h apparatus for combining the present invention with that of copending application Serial No. 204,318.

With reference to the diagrammatic View of Figure 1 of the appended drawing, it is known that, for the application of the bottom casting process, there is used a moulding box a, comprising a runner cup b, into which the metal is poured in order to give it access by a down runner c, which is substantially vertical, to a feed runner d arranged at the lower part of the moulding box. At the gate e of this runner, takes place the desired upward entry of the metal into the work P to be fed, which is often provided at its top with one or more protective risers f.

It is also known that, for the casting of light alloys, that are very liable to oxidation, bottom casting is chosen in practice on account of its known advantages relatively to other casting processes.

Nevertheless, it has been observed that an abundant flow of metal into the down runner produces, notably at the beginning of pouring,

splashing of metal at the base of the down runner and evolves serious oxidation of metallic particles with the formation of an oxide scum which is sometimes found on the upper parts of the moulded work.

The present invention allows considerable reducing and even fully obviating these undesirable effects.

When applied in combination with the invention described in the parent application Serial No. 204,318, led on January 4, 1951, of which this application is a division, this invention enables obtaining, particularly in the moulding of light alloys, castings having a structure superior to that obtained by either of the known casting processes used separately. The parent application relates to a process of bottom casting in which heat insulated sheaths are used, that surround the air holes in the space in which the risers are formed.

CTI

In principle, the moulding process according to the invention consists of admitting the metal to the bottom of the moulding box or the like, no longer by a down runner which is substantially vertical and is located at a iixed point in the moulding box, but through an independent movable conduit arranged outside the box and the position of which can be progressively varied at the Will of the operator, from a substantially horizontal position at the beginning of the pouring, to a more or less vertical position at the end of the pouring.

An apparatus for carrying out this process is shown in Fgure 2 of the appended drawing.

At the bottom of the moulding box, that is to say in the lower element of this box, if it comprises, as an embodiment, two elements, is arranged an orifice provided with a bearing l, in which is rotatable, in a fluid-tight manner, the bent end of an insulated pouring conduit 2b', the other end of which expands so as to form a runner cup 3. An operating handle li, allows a progressive varying of the inclination of the pouring conduit from the horizontal to the vertical and back. The bent portion, 2a enters the sand of the mould at the level of the work to be fed; it may, therefore, open in the feed runner d (Figure 1).

At the beginning, the pouring takes place in the lowermost position of the pouring tube, that is in the position near to the horizontal (as shown in full lines in the figure). Feeding is thus produced without falling oi the metal during this first step, whereby the above described inconveniences of bottom casting are obviated. Then, by means of lever 4, or the like, the assembly of the pouring conduit and of the runner cup is progressively lifted until the end of the pouring (dotted lines in the figure).

The device can be adapted, by suitable modiiications, to any one of the Various types of moulding boxes as normally used.

It produces remarkable results, particularly in the moulding of light alloys when applied in combination with the process described in the above parent application.

Figure 3 shows a vertical cross section through the feed runner for themetal and through the riser of a device for carrying out the process according to the invention when applied in combination with the process described in the parent application.

In Figure 3 are shown the insulated and feed runner 2a, 2b and the operating handle 4. The riser is formed in the air hole f, Which, in the figure, has the shape of a truncated cone, the larger base of which is arranged at the lower part of the riser, that is at the top of the Work P. Said air hole is formed with a sheath 5 which is surrounded with an envelope 5a and the space 6 between the sheath and the envelope is lled with a heat insulating material. The envelope 5a also has the shape of a truncated cone, the larger base of which is arranged upwards in order more easily to remove the sheath, by means of the handle 1'.

We claim:

1. A device for moulding foundry castings by bottom casting comprising a stationary moulding box, and a pouring conduit therefor, said pouring conduit being provided with a pouring cup at one end and being rotatably connected at its opposite end at substantially the lowermost level of the mould in a fluid tight manner, said pouring conduit being mounted for rotation in a substantially vertical plane.

2. A device for moulding foundry castings by bottom casting comprising a stationary moulding box, and a movable filling conduit therefor, said lling conduit being provided with a pouring cup at one end and being movably connected at its opposite end to the mould at substantially the lowermost level of the mould in a duid-tight manner, the pouring cup end of said lling conduit being capable of being gradually raised in a substantially vertical plane whereby the upper portions of the mould can be filled.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 574,616 Lewis Jan, 5, 1897 649,044 Cochran May 8, 1900 1,315,944 Brunner Sept. 16, 1919 1,739,222 Gathmann Dec. 10, 1929 2,063,815 Lewis Dec. 8, 1936 2,186,260 McWane Jan. 9, 1940 2,195,960 Morris Apr. 2, 1940 2,231,813 McDonald Feb. 11, 1941