United States atent [191 Gyongyos 1 Sept. 17, 1974 CONTINUOUS CASTING OF NON-FERROUS METALS [75] Inventor: Ivan Gyongyos, Montana,
21 Appl. No: 447,151
Related US. Application Data [63] Continuation of Ser. No. 309,800 Nov. 27. 1972,
3.11 1,824 11/1963 Firth 64/30 C 3,342,251 9/1967 Nagin 3,605,868 9/1971 Giadorou 164/279 Primary Examiner-J. Spencer Overholser Assistant Examiner-John S. Brown Attorney, Agent, or FirmErnest F. Marmorek [57] ABSTRACT A continuous casting machine is disclosed of the kind having a mold formed by a cooperating pair of endless sets of articulated mold blocks which are driven at the same speed so that over an advancing portion of their run they engage with each other and define between them a moving mold cavitiy. The advancing portion of the run of the blocks is straight and inclined to the horizontal at 45 or less. The blocks of the lower set move downwards as they leave the advancing portion of the run, and to prevent their weight from pulling apart the blocks occupying the advancing portion of the run, a brake is provided at the downstream end of the advancing portion of the run. The action of the brake opposes the pull exerted by the weight of the blocks leaving the advancing portion.
4 Claims, 6 Drawing Figures CONTINUOUS CASTING OF NON-FERROUS METALS This is a continuation, of application Ser. No. 309,800, filed Nov. 27, 1972, and now abandoned.
A machine for the continuous casting of strips of non-ferrous metals, such as aluminum and aluminum alloys, and hereinafter referred to as of the kind described, has a mold formed by a cooperating pair of endless sets of articulated mold blocks which are driven at the same speed so that over an advancing portion of their run they engage with each other and define between them a moving mold cavity.
In machines of this kind, the two endless sets of mold blocks are preferably driven by gearwheels which engage with toothed edge segments, each mold block having two of these segments, one at each side of the machine. The driving gearwheels, also one at each side of the machine, can engage with the toothed edge segments at any straight portion of the run of the blocks. The advancing portion of the run is generally straight as is a return portion.
An example of such a machine is disclosed in U.S. Pat. No. 3,570,586 of Lauener. In this machine the sets of mold blocks are connected to guiding and driving parts by supporting and attachment devices which are thermally insulating. The abovementioned patent also discloses the casting of wide strips, for example, in column 7, lines 51 and 52.
In the operation of machines of the kind described it is important to ensure that over the advancing portion of their run, the individual mold blocks of each set do not become separated from each other, leaving gaps between them. In a machine in which the advancing portion of the run is inclined for instance at a downward angle between and 45 to the horizontal, gaps can open up between the individual mold blocks of the lower set because of the pull applied by the weight of the blocks which move downwards away from the advancing portion of their run before returning to the upstream end of the machine. These gaps are additional to the unavoidable gaps resulting from manufacturing tolerances. An undesired looseness can also be produced in the upper set of blocks.
In accordance with the present invention in a machine of the kind described with the advancing portion of the run of the blocks inclined at an angle between 0 and 45 to the horizontal, at least the lower one of the two sets of blocks is provided with a brake at the downstream end of the advancing portion. The action of the brake opposes the pull due to the weight of the blocks moving downwards away from the advancing portion and thus prevents the weight from opening up gaps between blocks while moving along the advancing portion of the run, or at least reduces such gaps.
The brake is preferably adjustable so that the braking force applied to the mold blocks can be regulated to suit operating conditions. It is usually desirable for brakes to be provided on both sides of the machine and to be set tightly enough to prevent entirely any opening up of gaps between the mold blocks. However a slight gap is not a serious matter, provided that it is too narrow to allow molten metal to enter. An entire absence of gaps is necessary only if the cast strip has to be of the highest quality.
One example of a machine of the kind described, and two examples of brakes with which the machine may,
in accordance with the invention, be provided are illustrated in the accompanying drawings, in which:
FIG. 1 is a diagrammatic perspective view of the machine;
FIG. 2 is a perspective view of the lower set of mold blocks seen in the direction indicated by the arrow 11 in FIG. 1;
FIG. 3 corresponds to FIG. 2, but shows the lower set of blocks fitted with the first example of a brake;
FIG. 3a illustrates the side of the machine opposite to the one shown in FIG. 3;
FIG. 4 corresponds to FIG. 3, but shows a brake of different construction; and,
FIG. 5 shows a detail, drawn to a larger scale, of the brake represented in FIG. 4.
FIG. 1 shows a machine of the kind described, with an upper set 10 of mold blocks 12 and a lower set 11 of blocks 13. The curved arrows indicate the direction of circulation of the two sets of blocks. Over an advancing portion 14 of their run, each block is in contact both with adjacent blocks of itsown set and with an opposing block of the other set. The advancing portion 14 of the run is rectilinear and inclined at an angle of 3 to the horizontal. In the present example, six blocks of each set occupy the advancing portion of the run at any moment.
The upper mould blocks 12 have flat faces, whereas each lower mold block 13 has a recess 15, which forms the interior of the mold, the upper mold blocks acting merely as flat covers for the mold. The depth of the recesses 15 determines the thickness of the emerging cast strip 16.
The mold blocks of each set are interconnected by thermally insulating supporting and attachment parts to guiding parts, which are not shown in the drawing because they are contained within a housing 17. However the drawing shows toothed edge segments 18 of each block and side drive gearwheels 19, 20, which drive the mold blocks forward over the portion 14 of their run. A driving motor is shown at 21.
As shown in FIG. 2, when the machine is in operation gaps 22 open up between the individual mold blocks 13 of the lower set 11 over the advancing portion of their run. These undesired gaps open up due to the pull of the mold blocks at the downstream part of the lower set 11, where the mold blocks move downwards. The effect obtained is that the floor of the mold has gaps between the lower mold blocks 13 over the advancing portion 14 of the run, as represented in FIG. 1, that is to say where the lower mold blocks 13 are in contact with the upper mold blocks 12. These gaps in the floor of the mold are obviously undesirable.
To overcome this problem, a braking effect is applied at least to the lower mold blocks 13 at the downstream end of the advancing portion of the run, so as to close the gaps, or rather so as to prevent the gaps from opening up in the first place. FIG. 3 shows a braking device gaps from opening up between them over the length 14.
There are driving gear trains 19, 20 and brakes 23, 24, 25 and 26 on both sides of the machine, the axles carrying the gearwheels 19, 20 and 24 extending right across the machine, between the two sides. Both driving and braking are therefore equally applied at both sides of the machine. While FIG. 3 illustrates the right side of the lower mold block chain when view in the direction of casting, FIG. 3a illustrates the left side of the same block chain when viewed in the direction of casting.
FIGS. 4 and show a braking arrangement of different construction. A toothed wheel 27 engages with the toothed edge segments 18 of the lower mold blocks 13. A braking effect is applied adjustably to the wheel 27 as follows. The gearwheel 27 has a central drilling countersunk at both ends to give conical internal surfaces 28 which engage with the surfaces of two conical rings 29. When the machine is in operation friction between the surfaces 30 of the conical rings 29 and the internal conical surfaces 28 of the gearwheel 27 produces a braking effect which, through the gearwheel 27 and through the toothed edge segments 18, is applied to the lower mold blocks 13, preventing gaps from opening up between them. The conical rings 29 are spline mounted on a shaft 31, so that they cannot rotate on the shaft. At its base the shaft 31 is welded, at 32, to the wall of the housing 17. The shaft 31 stops here, that is to say it does not extend across the machine to the braking device on the other side. The two conical rings 29 are thrust towards each other by plate springs 33, which are compressed by means of a nut 34. By adjusting the nut 34 the operator of the machine can sensitively adjust the thrusts with which the two conical rings 29 are thrust towards each other, and therefore the friction between the conical rings 29 and the gearwheel 27, giving a sensitive adjustment of the braking effect applied to the lower set 11 of mold blocks.
A variety of other braking arrangements can if desired be used, for example a brake shoe can be arranged to act directly on the outer edges of the toothed edge segments 18.
I claim:
l. A machine for the continuous casting of non- 4 ferrous metal strip comprising articulated upper and lower endless sets of molded blocks wherein each said set of mold blocks is operable for movement around a closed run, mounting means for each said set of mold blocks for supporting said set of mold blocks with a succession of said blocks of each said set being disposed rectilinearly to form an advancing portion of said runs that is inclined to the horizontal at an angle between 0 and 45, said lower set of said mold blocks moving downwardly upon leaving the advancing portion of said runs, the succession of said blocks of said upper set being in engagement with the corresponding succession of said lower set of mold blocks for forming a mold cavity therebetween, driving means arranged on both sides of said machine for driving said endless sets of mold blocks around said respective closed runs in synchronism with one another and continuously operating frictional braking means disposed to engage a portion of said mold blocks of at least said lower set proximate the downstream end of said advancing portion, said frictional braking means exerting a continous restraining force to said lower set of mold blocks in a direction opposite to the movement of said lower set of mold blocks for preventing the weight of said lower set of mold blocks at the downstream end of said advancing portion for pulling apart said mold blocks in the remaining upstream section of said advancing portion said continuously operating frictional braking means being positioned on both sides of said advancing portion proximate the downstream end thereof.
2. A machine according to claim 1, including a plurality of toothed segments, at least one of said segments being carried by each of said mold blocks, and said frictional braking means being adapted to engage said tooth segments.
3. The machine as claimed in claim 1, wherein said continuously operating frictional braking means is adjustable.
4. The machine as claimed in claim 1, wherein said braking means comprises a brake shoe on each side of said machine.