US1684994A

US1684994A - Apparatus for casting under pressure

Info

Publication number: US1684994A
Application number: US234772A
Authority: US
Inventors: Jorgen-Jensen Erik
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-03-22
Filing date: 1927-11-21
Publication date: 1928-09-18
Anticipated expiration: 1945-09-18
Also published as: GB279345A

Description

Sept. 18, 1928.

E. JORGEN-JENSEN APPARATUS FOR CASTING UNDER PRESSURE Filed Nov. 21, 1927 Patented "Se t. 1a, 1928.

, UNITED sures am Joanna-muslin, or :anenasrou, nmnrmenm, nnenmn.

arranarus iron cas'rme unnnia rnnssuan. 1

Application fled November 31, 192?, Serial No. 884,772, and in Denmark March 22, 1827.

My invention relates to the production of castings under pressure.

Within recent years the use of air pressure in foundry pract1ce has found favour for the reason that good filling of the moulds and greater density of metal can thereby be secured. The apparatus employed for pressure casing however, frequently sufiersfirom the drawback that the crucible contalnmg the m molten metal, after a period of use, becomes cracked or ruptured for the reason that it 1s unable to withstand the difierential pressure to which it is subjected.

To avoid this drawback it has been ro- 1 posed to enclose the cruciblein a cover or ll to which the'air pressure is sup lied so that the crucible, both externally an internally, is subjected to uniform pressure conditions. With such an arrangement there still exists the drawback that it is not readily possible to evacuate the crucible of all molten metal in the casting-operation and consequently the outlet therefrom and the inlet to the mould are likely to become choked with chilled metal. I

The apparatus according to the present invention is characterized by the fact that the molten metal, by combined air pressure and syphonic action, is caused to run through a w tube in the bottom of the crucible, while the saidcrucible is surrounded by a compressed air bell in such a manner that the walls of the crucible are not exposed to any differential pressure.

- One construction of the improved a paratus is illustrated in vertical longitu inal section in the accom anying drawing.

Referring to the atter, 1 is a plate below which the mould 2 is disposed, in such a manner that the gate 3 of the same is situated directly below the corresponding opening 4 in the plate 1. Above this opening there is placed on the plate a crucible 5 at the centre of which there is provided a tube ,6 the mouth of which, as shown, is situated above the normal level of molten metal in the crucible, and which is adapted, when the crucible is placed in position, to communicate with the opening 4 of the plate 1 and the gate 30f the mould 2.

, Over the crucible and on the plate there is placed a bell 7 from which a smaller bell 8 is suspended, which latter, when the hell 7 is in position, projects down to the bottom of the crucible and encircles the tube 6, holes being provided, however, at the bottom edge of the 7 bell 8, in such a manner that the masses of molten metal inside and outside of the bell 8 will be in communication with one another. By way of a pipe 9 compressed air maybe directed into the hell 7, in such a manner that the molten metal contained in the'crucible 5 outside the bell 8, owing to the air pressure, will be pressed through the holes at the lower edge of the hell 8 up the interior of the latter and down the tube 6 into the mould 2. As the quantity of molten metal in the crucible 5 may be adjusted to correspond to the volume of the mould, the air pressure, after the mould has been filled,will act directly on the metal contained in the mould. Furthermore, owing .to the provision of the hell 8 and the particular arrangement of the latter with respect to the tube 6, It will be observed that when the molten metal flows into the tube due to the pressure applied to it a syphonic action will be set up. This action will not only assist in the evacuation of the crucible but will aug- .ment the air pressure acting directly on the metal in the mould.

In the herein described embodiment the constructional details have been omitted for the'sake of simplicity, but obviously means must be rovided for securing a connection between t e mould 2 and the plate 1 and between the latter and the bell 7 as well as for suspending, in suitable manner, the interior boil 8 from the outer bell 7. In the latter respect the means may comprise a spring 10 as shown. Y a

What I claim and desire to secure by Letters Patent of the'United States is':-

1. Apparatus for casting under pressure, comprising a crucible adapted to contain molten metal, an outlet from said crucible, means for causing the molten metal to flow through said outlet by combined air pressure and syphonic action, and a compressed air bell surrounding said crucible suchwise that the walls of the crucible are not exposed to m difierential pressure.

2. Apparatus for casting under pressure, comprising a crucible adapted to contain molten metal, an outlet from said crucible, a a mould, means for causing the molten metal 105 to flow through said outlet into said mould by combined air pressure and syphonic action, and'a compressed air bell arranged suchwise that the walls of the crucible are free from exposure to difierential pressure, said air no tom of said crucible and having an outlet adapted, when the crucible is laced in position to communicate with an i et to a mould, a bell coverin said crucible, means for supplying air un er pressure to the interior of the said bell, and another bell arranged within said first mentioned bell and covering said tube, for the pur ose set forth.

4. Apparatus or casting under pressure, comprismg a crucible adapted to contain molten metal, a tube extending upwardly from the bottom of said crucible, an outlet to said tube adapted to communicate with an 1 inlet to a mould, abell adapted to cover said crucible, means for supplying air under pressure to the interior of said bell, another bell arranged within said first mentioned bell and covering said tube and means for suspending said second mentloned bell from said first mentioned bell, for the purpose set forth.

5. Apparatus for casting under pressure, comprising a mould, a crucible adapted to contain molten metal a tube extending from the bottom of said crucible and having an outlet adapted to communicate with an inlet to said mould, a bell covering said crucible, means for sup lying air under pressure to the interior 0? said bell, and another bell situated within said first mentioned bell and around said tube the arrangement being such that the crucible is evacuated of molten metal by combined air pressure and syphonic action and such that said air pressure acts directly on the metal in the mould and'is augmented by said syphonic action.

ERIK J ORGENJENSEN.