US1846087A

US1846087A - Apparatus for casting molten metal under pressure

Info

Publication number: US1846087A
Application number: US339992A
Authority: US
Inventors: Christensen Reinhardt Valdemar
Original assignee: Individual
Current assignee: Individual
Priority date: 1928-02-29
Filing date: 1929-02-14
Publication date: 1932-02-23
Anticipated expiration: 1949-02-23

Description

Feb. 23, 1932. R. H. v. cHRxsTENsEN APPARATUS FOR CASTING MOLTEN METAL UNDER PRESSURE Filed Feb.

14, 1929 3 SheetS- Feb. 23, 1932.

,zlyww WLM, CM; XMM- Feb. 23, 1932. R. H. vA cHRlsTENsr-:N 1,846,087

APPARATUS FOR CASTING MOLTEN METAL UNDER PRESSURE Filed Feb. 14, 1929 3 Sheets-$heet 3 nection with the pressure source.

Patented Feb. 23, 1932 UNITED STATES PATENT OFFICE APPARATUS IOR CASTING IOLTEN METAL UNDER PRESSURE Application led February 14, 1929, Serial No. 339,999, and in Denmark February 29, 1928.

This invention relates to die casting of molten metal under air or gas pressure and is especially adapted for use in gross pro duction of castings.

5 In this art it is known to use a casting reservoir or ladle in the form of a curved tube which is dipped into the crucible and one end of which is permanently connected to a conduit which through a valve has con- This arrangement, however, can involve disastrous accidents if the valve leaks as the molten pressure source being arranged directly over the gate of the mould. In this case a tight connection is obtained whereby that the ladle at the side opposite to the mouths of the tube is provided with a boss against which pres sure is exerted. This construction, however,

is unpractical in many respects. For example it is diiicult to. obtain tightness at both ends of the curved tube, among other things on account of the different heating of the co-acting parts.

According to the present invention the above named drawbacks are overcome whereby the connection between the pressure conduit, the ladle and the mould is estab lished by clasping the ladle between the outlet of the pressure conduit and the gate of the mould. This can be performed by arranging the mouth of the pressure outlet and the mouth of the mould ate opposite each other in mutually mova le members, between which the ladle can be clasped so that the cavity thereof will be opposite to both said mouths.

According to the present invention the pressure with which the parts of the mould are forced together may be utilized to clasp the ladle, the member in which the mouth of the gate is arranged being for instance freely movable so that it will be pressed against the ladle when the mould parts are Figure 1 is a top view of an apparatus for 60 casting molten metal under pressure using the method according to this invention,

Figure 2 is an end view, partly in section along the line II-II in Figure 1,

Figure 3 is a side view partly in section ce of the ladle of the apparatus, drawn on a larger scale,

Figure et is a cross section of the same on the line IVIV in Figure 3 Figure 5 lis a side view of a modification 70 of the apparatus,

Figure 6 is la section of the same on the line VI-VI in Figure 5, and

Figure 7 is a longitudinal section of the ladle, appertainin to the apparatus shown 75 in Figures 5 and drawn on a larger scale. In Figures 1 and 2, 10,11 and 12 are clamping members. The member 10 is secured at the end of twotparallel rods 13 and 14while the two other members 11 and 12 can slide 80 along said rods. The member 12 can be acted upon by two toggles 15, which by means of gearings 16 are operated by a hand wheel 17. The mould in which the metal is cast con' sists of two

parts

18 and 19 secured to the 85 members 11 and 12 respectively. The gate 20 of the mould is continued through the member 11 and terminates in a detachable nozzle 21.

The molten metal is transferred from the crucible 27 to the

mould

18, 19 by means of a ladle 22 which is suspended to swing freely on a crank pin or pivot 23 carried by an varm 24. This arm is secured to one end of a shaft 25 journalled parallel to the

rods

13 and 14. 95

The shaft 25 can be operated by a hand lever 26 at the opposite end thereof.

The crucible 27 is positioned in such a manner that. the ladle 22 can be submerged into the crucible by swinging the shaft 25 through 100 one half revolution. The Crucible 27 is enclosed in a heat insulating, reproof casing 28 and is heated by means of an oil burner 29 of any known kind.

In addition to the crucible 27 the casing 28 encloses the lower part of a boiler` 30 which is also heated by the burner 29, the furnace of the boiler being connected to the annular combustion chamber 33 surrounding the Crucible by

ducts

31 and 32. The heating of the boiler 30 can be adjusted by a displaceable damper 34 arranged in the duct 31.

From the steam space of the boiler 30@I conduit 36 provided with a valve 35, Figure l, leads to the clamping member 10. In continuation of the conduit 36 a channel 37 is provided through the member 10. The opening of the channel 37 at the inner side of the member l0 terminates in a nozzle 38. Y

l The cavity of the ladle 22 consists i1i`two

compartments

39 and 40, Figures 3 and 4, interconnected below and having at the top an inlet 41 for the pressure medium and an outlet 42 for the molten metal, respectively.

The inlet 41 and the outlet 42 are substantially aligned so that the cavity of the ladle can be interposed between the pressure conduit 36 and the

mould

18, 19 by clasping the ladle between the members 10 and 11.

The compartment 39 is greater than the compartment40, and the cavity of the ladle 22 is so chosen that the ladle can deliver just a mould charge. Therefore to a certain apparatus there are a number of ladles the cavities of which are of different volumes and for a certain mould a ladle is selected'the cavity of which corresponds to that of the mould.

The apparatus is used in the following manner:

By actuating the hand lever 26 theshaft 25 is rotated so that the ladle 22 is swung until it is submerged in the molten metal in the Crucible 27. During this movement the ladle- 22 hangs vertically down from the pivot 23 owing to the action of the gravity as the centre of gravity of the ladle lies below the point of suspension. Now the metal flows into the cavity of the ladle through both

openings

41 and 42. When the cavity has been lled with molten metal the shaft 25 is swung in the opposite direction until the ladle 22 assumes the position shown in Figure 1 in which thenozzle 38 is aligned with the inlet 41 and thenozzle 21 is aligned with the outlet 42. Then the toggles 15 are operated by means of the hand wheel 17 so that the

mould parts

18 and 19 are pressed together and simultaneously the ladle 22 is clamped between the

nozzles

38 and 21 on the members 10 and 11 respectively. Finally the valve 35 is opened which causes the metal in the ladle 22 to be forced into the

mould

18, 19 which will be filled up by the metal as the air originally present in the mould will be driven out through narrow apertures for this purpose, through which the metal can not pass.

In the embodiment shown in Fi res 5 and 6 the Crucible isarranged behind t e casting apparatus enclosed in a cas-ing 28a. The ladle 22a is suspended on a crank pin or pivot 23a on an arm 24a as in the previous case, but in Figures 5 'and 6 the shaft 25a of the arm 24a is arranged perpendicularly to the longitudinal direction of the apparatus and journalledvin -a bearing 50. The ladle is transferred from the Crucible to the mould and vice versa by the movement of the mould part 19a which is moved when the castin is removed from the mould. To the mem er 12a carrying this mould part is adjustably secured a rod 51 the end of which is formed as a rack 52 slidable in a guide 53, Figure 6.

The rack 52 meshes witha pinion or a toothed sector 54 secured to the end of the shaft 25a.

When the mould is in closed position, Figure 5, one end of the rack 52 meshes with one end of the toothed sector 54 and the arm 24a assumes such a position that the ladle 22a is situated between the nozzles 21a and 38a of the mould gate and the pressure conduit 36a respectively, with the inlet and outlet of its Cavity in connection with the mouths of the said nozzles, the exact position of the ladle being determined by adjustable screws 55 fixed to a yoke or strap 56 carried by the rods 13a and 14a. When the casting process has been performed the mould part 19a is removed from the other mould part 18a. During the first part of this movement the rack 52 meshes with the sector 54 and the arm 24a' and the ladle 22a are transferred tothe position shown in dotted lines in Figure 5. In this position a projection 60 on the arm 24a rests against a fixed sto 57 which may be adjustable as shown. uring the further movement of the mould part 19a no co-action takes place between the rack and the toothed sector.

It will be understood that theoretically it is suiicient that the

gearing

52, 54 transfers the ladle from an end position to a position in which the centre of gravity of the ladle is beyond the axis of the shaft 25a as the remainder of the movement may occur under the action of gravity.

The means for moving the clamping member 12a consists in toggles 15a, gearings 16a and a hand wheel 17a as in the previous case.

The apparatus is supported by standards 58 which together with the Casing 28a are ar-V tid the metal surface in contact with the pressure medium the pressure on the metal will increase when the surface of the metal passes from the part 39a to the part 395.- "I"he cross section may vary otherwise than mdlcated 1n Figure 7. Generally according to the present invention the cross section of the branch connected to the pressure source varies in the longitudinal direction of the branch in such a manner that the pressure on the metal will vary in accordance with the desired progress of the casting process.

The ladle shown and described has the advantage that it can be removed and replaced by an other ladle if necessary. The 'ladle 1s very strong and can resist a conslderable pressure owing to it being block shaped externall Frthermore it is advantageous that the Crucible be arranged so that it can easily be removed and substituted by a crucible containing a diferent metal so that the casting of a new metal can be commenced in a short period of time. The apparatus described does not require any special shape or material of the crucible so that these factors can be arbitrarily chosen and existin crucibles and appurtenant furnaces may e used if desired. It is a feature of the apparatus that without any alteration it can be used for casting all metals suitable for the art in question, the melting point of which lies below 1200 centigrades.

The invention is not restricted to the use of steam as a pressure medium.

Having thus fully described my invention I claim as new and desire to secure by Letters Patent:

l. In an apparatus for casting molten metal under pressure, a separate ladle having two compartments connected below and extending upwards to the same level and terminating in aligned inlet and outlet ducts, said ladle being adapted to receive molten metal when it is submerged into the metal until the said ducts lie under the surface thereof.

2. ln an apparatus for casting molten metal under pressure, a mechanical movement adapted to transfer a ladle with aligned inlet and outlet ducts from a Crucible to a mould and vice versa, in such a manner that in each position during the transfer the inlet and outlet ducts of the ladle lie substantially in the same horizontal plane.

3. ln an apparatus for casting molten metal under pressure, a casting reservoir with a substantially U-shaped cavity terminating in horizontally aligned ducts, said reservoir being suspended to swing freely at a point over its center of gravity.

4. in an apparatus according to claim 2, in which the said mechanical movement includes a crank mechanism with a horizontal crank pin on which the ladle is adapted to be suspended swingably.

5. In an apparatus for casting molten A i prising fixed abutments for defining the end positions of the crank mechanism.

7. A casting reservoir for use in die casting, comprising a body with a substantially U-shaped cavity having two branches, one of the said branches consisting of two parts, each of which -has a substantial constant cross-section, the cross-section of the lower part being greater than that of the upper part.

8. An apparatus for casting molten metal under pressure, comprising a conduit having an outlet and adapted to be connected to a pressure source, a mold having an inlet and adapted to be moved bodily in a straight path towards and away from the outlet of said conduit, a casting reservoir with a cavity serving to receive the molten metal and debouching in oppositely directed ducts, said casting reservoir being adapted to be moved bodily into and away from an operative position between said outlet and said inlet, and means for bodily moving said mold to thereby press the same against the casting reservoir transmitting the pressure through the latter to outlet of said conduit.

9. The apparatus of claim 8, in which said conduit with its outlet is stationary and saidV mold comprises two separable mold parts one of which is provided with said inlet, the said means for bodily moving the moldbeing adapted merely to act on the mold part not provided with the inlet whereby the other mold part provided with the inlet and said casting reservoir are clamped from opposite sides between said mold part not provided with the inlet and said outlet of the conduit.

l0. An apparatus for casting molten metal under pressure, comprising a conduit having an outlet and adapted to be connected to a pressure source, a mold having an inlet, said mold and conduit outlet being relatively movable in a straight path concentrically towards and away from each other, a casting reservoir or ladle having an inlet duct and an outlet duct, means for bodily moving said casting reservoir from a position suitable for the filling of the same with molten metal to an operative position between said mold inlet and conduit outlet and vice versa, and means for relatively moving said mold and conduit outlet toward each other to clamp the casting reservoir therebetween when in its operative position.

l1. The apparatus of claim 10 in which said means "for bodily moving the 'casting reservoir includes' a crank having a crank pin from whichsaid casting reservoir is suspended.

12. An apparatus for casting molten metal under pressure, comprising a conduit having an outlet and adapted to be connected to a pressure source, a mold adapted to be bodily moved in a straight path towards and away from said outlet, a casting reservoir adapted to contain a charge of molten metal and to be moved into and away from an operative position between said mold and outlet and mold driving means for moving said mold in said straight path against .theD casting reservoir when in its operative position to thereby press the casting reservoir against the said outlet of the conduit whereby connection is not established between said casting reservoir and outlet before the mold has engaged the casting reservoir under the influence of said mold driving means.

In testimony whereof I have aixed my signature.

REINHARD'I' HARALD VALDEMAR CHRISTENSEN.