US 2960736 A
Description (OCR text may contain errors)
\ Nov, 22, 1960 .1. PoUDEvlGNE 2,960,736
cAsTIN RA EMENT ALL MET Ls l| ll U 9 4 Il /0` /2 |1 i INVENTOR United tates Patent G 2,960,736 CASTING ARRANGEMENT FOR ALL METALS Jean Poudevigne, 2, Chemin Vicinal de lArgile, Marseille, France Filed Nov. 21, 1956, Ser. No. 623,707 Claims priority, application France May 30, 1956 1 Claim. (Cl. 22-147) In order to obtain clean and suitable pieces, the casting of metals requires certain precautions, thus when it is desired to avoid the cavities produced by the liberation of gases during cooling, dead heads are used. These dead heads also have the object of preventing central piping.
The object of the invention consists in an arrangement intended for the casting of all sorts of pieces of ferrous and non-ferrous metals, permitting of maintaining a regulable and constant pressure with the aid of an appropriate gas upon the mass of metal, while irrigating it to eliminate any central piping and to ensure a casting without heterogeneous area or micro-porosities or micro-piping, all with a mass of metal reduced to the minimum.
It is characterized by the means used, taken both as a whole and separately, and more especially by the maintenance in the molten state by an appropriate source of heat, of the surplus metal intended to eifect the filling of the mould, whilst subjecting the assembly to a determined and regulable pressure through the intermediary of the liquid mass.
In the accompanying drawings, given by way of nonlimitative example of one of the forms of embodiment of the object of the invention, the device is represented as a whole, seen in longitudinal section.
The mould or sand 13 is filled with metal, the mass 1 of which represents the piece to be obtained as cast.
The vessel which is to contain the excess quantities of metal 2 is of smaller section, but forms in its upper part a bell-mouth 3 with walls.
The bell 4 comprises a lower periphery with proled vertical edges 5 with protruding external horizontal shoulder 6, having a diameter greater than that of the bell-mouth on the walls of which it rests. In the axis of the bell 4 there is mounted a heat-generating element 7 dipping deeply into the mass of surplus metal.
The whole of the bell, forming an internal chamber 8, is rendered perfectly air-tight by a stopper 9 provided with a packing. An orifice 10 connects the interior of the chamber with the compressed gas delivery duct 11. This conduit comprises suitable Supervisory and closure members.
Thus the advantages and operation will be understood of this device, which is intended to increase the nal yield of the liquid metal. The surplus mass 2 of metal necessary for supplying the contraction of the piece 1 when it solidifies is maintained in the liquid state by means of the heat generator 7. This element is constituted so as to conform to the use for which it is intended, according to the metals. It is constructed of substances possessing exothermic properties, and its starting up can be effected on contact with the liquid metal. The ensuing reaction produces, by generation of calories, the heating of the surplus mass 2 upon which the pressure of the gas 11 acts. The pressure is constant upon the thrust surface 12.
Communication between the mold chamber 1 and the Supply of liquid metal is not interrupted before the central portions of the ingot solidify. This prevents the formation of internal cavities as a result of shrinkage of the casting metal, and avoids a partial vacuum in the mold chamber, because extra metal can ow in from the lead-in conduit 2.
Furthermore the molten mass permitting of obtaining a hydro-pneumatic pressureis distributed in the bell- Patented Nov. 22, 1960 ICC 2 mouth 3. The penetration of the peripheral edge 5 of the bell then constitutes a sealing joint, the effects of which are completed by the bearing of the stabilising shoulder 6 on the border of the bell-mouth. The pressures experienced can be very great without risk of leakages.
This collar of liquid metal surrounding the base of the bell further increases, by its solidication, the sealing against the gas pressure, due to the oppositely directed actions of its withdrawal and the expansion of the bell. The variation of height of the element 7 is obtained by screwing of the stopper or the addition of a connection.
In certain cases the use of an exothermic element generates gases which have to be evacuated by means of a tap lett open at the moment of casting and remaining so as long as is necessary. If the heat generating element is electrical it is possible, as soon as the compression level is reached, to re-close the tap and to admit the gas pressure. The casting and the operation being terminated, the device is withdrawn at high temperature, that is to say without having interrupted the arrival of the current, in order to avoid adherence of the cooled metal to the pieces in contact therewith. Thus whereas the center of the surplus part 2 is kept liquid, the walls thereof solidify over a reduced thickness by contact of the metal with the sand. This solidied sheath prevents losses of pressure and permits of obtaining an optimum form for the piping compensating for the contraction of the metal of the piece. Thus a signicant economy is obtained in the quantity of liquid metal necessary to obtain this result.
However the shapes, dimensions and arrangements of the different members can vary within the limit of equivalence as can also the materials or substances used for their manufacture, without thereby changing the general idea of the invention which has just been described.
In an ingot mold, a mold chamber to receive molten metal for solidilication into an ingot, said chamber having yan opening at the top, a lead-in conduit formed by the walls of said mold and having an increased cross-sectional area at its open upper end, the lower end of said conduit being in open communication with said mold chamber, a bell member seated by a peripheral ange on said walls at the upper end of said conduit to serve as a closure therefore, an annular wall depending from the bell member into said open upper end of said conduit and spaced inwardly therefrom, valve means on said bell member for the introduction of compressed gas, an electrical heating element mounted on the bell member and positioned to depend axially and in spaced relationship into said conduit for most of the length of said conduit, said molten metal filling said mold chamber and said conduit to a level above said depending Wall of said bell member whereby said metal lying axially and adjacent to said heating element is maintained in a molten state by said heating element as the metal solidies between said annular depending wall of the bell member and the Wall of said mold forming a gas-tight seal between said depending wall of the bell member and the wall of said mold.
References Cited in the tile of this patent UNITED STATES PATENTS 315,741 Henderson Apr. 14, 1885 506,518 Leibert Oct. 10, 1893 901,361 McCarty Oct. 20, 1908 1,913,434 Dumas June 13, 1933 1,918,734 Bornand et al July 18, 1933 2,152,528 Biggert Mar. 28, 1939 FOREIGN PATENTS 162,348 Great Britain Apr. 15, 1921 344,947 Great Britain Mar. 16, 1931 184,679 Austria Feb. 10, 1956