US2489479A - Feeding device for centrifugal casting machines - Google Patents

Description

Nov. 29, 1949 J. A. CAVALLIER 2,489,479

FEEDING DEVICE FOR CENTRIFUGAL CASTING MACHINES Filed Dec. 11. 1946 5 Sheets-Sheet 1 J. A. CAVALLIER Nov. 29, 1949 FEEDING DEVICE FOR CENTRIFUGALCASTING MACHINES F-iled Dec. 11, 1946 3 Sheets-Sheet 2 1949 J. A. CAVALLIER 2,489,479

FEEDING DEVICE FOR CENTRIFUGAL CASTING MACHINES Filed Dec. 11, 1946 3 Sheets-Sheet 3 Fig. 6

Patented Nov. 29, 1949 FEEDING DEVICE FOR CENTRIFUGAL CASTING MACHINES Jean Albert Cavalller, Nancy, France, assignor to Societe Pompes Noel,

French company Liven-dun, France, a

Application December 11, 1946, Serial N0. 715,505 In France December 20, 1945 1 Claim. 1

It is known that in the manufacture of pipes, by centrifugal casting, the molten metal is fed progressively into the mold by means of a ladle containing the quantity of metal necessary for the-manufacture of one pipe, such ladle having a section and a pouring speed such that its outflow is in proportion to the speed of translation of the mold in such a manner that the thickness of the pipes obtained is uniform.

In the known machines, it is necessary'to fill the ladle after each casting. As that operation is rather a lengthy one, it appreciably slows down the rate of manufacture. In addition, machines for centrifugation are generally grouped in a same workshop and fed with molten iron or other metal, by means of a single mother ladle. The result of this is that the feeding cycle of each machine is conditioned by the running 'of the others, the most rapid of which being slowed down by the slowest and the installation as a whole suffers from eventual irregularities in the operation of any of them.

The object of the present invention is an improved feeding device which provides a remedy for the aforementioned drawbacks.

According to one feature of the invention, the improved feeding device comprises a ladle of large capacity containing sufficient molten metal to cast successively several pipes.

According to one embodiment of the invention, the-ladle is provided with a single pouring spout and it is combined with control means such that it distributes successively, into a series of molds, the quantities of molten metal necessary for manufacturing several pipes or similar objects, consecutively.

According to another modification, the ladle is provided with two parallel spouts in such a way that during each of the successive casting operations, it distributes the metal into two molds.

In the accompanying drawings, given solely by way of example:

Fig. 1 is a diagrammatical elevation view with partial sections, of an improved feeding device combined witha single mold.

Fig. 2 is the graph of the rotation of the ladle during the course of the successive working cycles, rotation angles of the ladle being shown along the ordinate andtime periods being shown along the abscissa.

Fig. 3 is a partial section on a greater scale, of the ladle shown before the beginning of the casting operation.

Fig. 4 is a side view corresponding to Fig. 8.

- to contain the molten iron or other metal necessary for the manufacture of several pipes or similar objects.

Said ladle is rotatably mounted on horizontal crankpins 2 and, its cylindrical inside surface 3, is coaxial with the crank-pins 2 in such a way that the quantity of molten metal poured through the spout 4 of the ladle is proportional to the angle of rotation of the said ladle.

Under the spout 4 of the ladle isarranged, as is customary, a hopper 5 leading to a trough I mounted on a base 1 in an overhanging position.

The mold 8 is made to rotate around its axis XX, either horizontally as shown or slightly inclinedfrom the horizontal. Said mold is mounted inside a casing or carriage 9 moved by means of rollers l0, along a runway II and is able to be given a reciprocating movement by means of a hydraulic jack i2, the piston l3 of which is connected by the stem l4 and the bracket l5 to the casing 9.

The ladle l is tilted by the following mechanism: a bracket IS on the ladle is connected by a connecting rod Ila. to a piston no moving in a cylinder He. The latter is connected by a connecting rod H to a toothed sector l9 as shown at l8. ,Said toothed sector [9 rotates together with a drum 20. A brake band 2| secured at 22- is adapted to brake said drum when rotating in, the direction of arrow i The free end of said brake band is connected to a lever carrying a counterweight 2-3 which is connected by an operating rod 24 to a handle 25.

In mesh with the toothed sector is is a pinion 26, fitted on a shaft 21, at the extremity of which is keyed a sliding friction clutch or cone 28.

The cone 28 cooperates with a gear wheel 29,

The outlets of the valves 31 and 38 are branched in parallel to a pipe 39.

The pipe 39, fitted with a discharge, cock 40 leads to the aforesaid cylinder He by means of a flexible pipe 4|.

The pipe 39 is fedwith a compressed fluid through the medium of a three-way cook 42 inserted between the'inlet pipe 43 (provided with a cook 44) and the outlet pipe 45.

The spindle of the cook 42 is fitted with two pawls 45 and 41, staggered laterally and cooperating respectively with fingers 49, 48 correspondingly staggered carried by the carriage 9 for the mold.

The operation is as follows: In the initial inoperative position, the ladle I is horizontal and the cook 42 puts into communication, through its port 59, the inlet and outlet pipes 39, 45 in such a way that on the one hand, the contact between the clutch 28 and the gear wheel 29 is broken through the action of the spring 35 and on the other hand, the piston Ilb is at its low position. The discharge cook 40 is closed.

The ladle I is then filled with molten metal as far as level with the spout 4. At that moment, by means of the hydraulic jack I2, the carriage 9 is moved to the left (arrow P). A little before carriage 9 reaches its upper position, the projection 49 enters into contact with the pawl 46 and causes it to rock whereby the three way cock 50 is rotated and the pipe 39 is put in communication with the inlet 43. In that way, compressed air is admitted, on the one hand into the cylinder He, thus causing the piston Nb and the connecting-rod IIa to rise and, on the other hand into the cylinder 34 causing the clutch 28 to engage the wheel 29.

Due to the rising of the piston I'Ib in the cylinder I 1c, the ladle rapidly turns in the direction of the arrow f, by an angle corresponding to the stroke of the piston Ilb. Said instantaneous rotation of the ladle is shown diagrammatically at a b in Fig. 2.

At the same time, the motor 3| which is maintained constantly in rotation, drives the sector I9, through the medium of gear 29, clutch 28, shaft 21 and pinion 25. The sector will thus ensure a further rotation of the ladle around its axis 2 in the direction of arrow j.

Thanks to the action of the piston I lb, the level of the molten metal in the basket I is suddenly brought over the rim of the spout 4 whereby the casting operation is instantaneously initiated. The flow of molten metal continues as the result of the prolonged rocking of the ladle under the action of the sector I9. The liquid mass runs into the hopper 5 then into the trough 6 at the end of which it falls into the mold 8 which, during that time, has come to the inward position as shown at 8a in dotted lines.

'At that moment, carriage 9 is withdrawn outwardl in a direction opposed to that of the arrow f and, a little before the end of the stroke, the projection 48 coming into contact with the pawl 41 causes the cock 42 to turn, the port 50 of which interrupts the communication of this piping 39 with the piping 43 and reestablishes communication of that pipin with the discharge pipe 45. The result of this, in the first place, is a drop of the piston IIb in the cylinder Ila and consequently, the immediate interruption of the flow of molten metal.

Furthermore, as the result of the depression that establishes itself in the piping 49, the nonreturn valve 38 is closed and the air contained in the cylinder 34 escapes towards the piping 39 through the medium of the regulating valve 31 forming a by-pass and a temporization device. Under the action of said regulating valve, a retard is set up at the declutching of the cone 28 from the wheel 29 and during a short lapse of time.

the sector I9 continues to rotate, and to raise the ladle, the efiect of this is to bring the level of the molten metal flush with the spout 4, that .is to say in the departure position for a fresh casting operation.

0n the graph of Fig. 2, there has been shown in b c the uniform rotation of the ladle during the course of the period of casting, at o d the instantaneous return at the moment of the interruption of the casting subsequent to the drop of the piston Nb and at d e the slow rising of the ladle for the purpose of reachin a new departure position for a subsequent casting operation.

An operational cycle corresponding to the casting of a pipe is thus terminated.

Thanks to the increased capacity of the ladle, it is possible to cast several pipes successively, without the necessity of filling the ladle again and the successive cycles are shown ata b c d e a b c d e a b c d e After the last cycle the ladle should be allowed to drop for filling purposes. This is obtained by pulling the handle 25 upwardly. The effect of this is to raise the counterweight 23, to release the brake 2I and to free the drum 20. The sector I9 and the ladle I will then fall back under their own weights.

It should be noted that the band brake 2i acts in a single direction and does not therefore present any opposition to the raising of the ladle at the moment of the castings.

During the course of manufacture, it may be necessary to interrupt the casting abruptly, due to some sort of incident. That result is obtained by opening the discharge cock 40, the discharge flow of which is greater than the admission flow of the control valve 44. The opening of the valve 40 will cause the pressure in the piping to fall and this at once interrupts the casting as explained above.

To enable the successive castings to proceed without incident in spite of the length of time the liquid metal has remained idle in the ladle, it is necessary to prevent the molten mass from cooling and in order to retain a steady flow for those castings the spout 4 must be prevented from becoming clogged.

Those results are obtained by providing the ladle I (Figs. 3 to 7) with a lid 52 whose lower face is provided with a refractory lining 53. This lid, rotatably mounted on the pivot 54, carried by bearings 55 fixed to the ladle is actuated by a crank arm 56 pivoted to a connecting-rod 51, which carries a handle 58, the connecting-rod being supported by a bracket 59, fixed to the ladle I. The lid 52 is balanced by a counterweight 60 held by two arms 6|. The lid 52 is provided with a depending rib 62 made of a refractory brick fitting between the side walls 53 of the ladle and dipping into the molten mass 5|.

The above device is used as follows: At the time of the filling, the workman in charge of the casting pulls the handle 58 to the right (Fig. 4) to open the ladle. He then fills the ladle with the molten metal and closes the lid, as soon as the filling is completed. During successive operations of casting, the liquid slag that may have ried by a vertical screw I3.

been carried along by the metal, collects on the upper part of the bath and its flow towards the spout 4 is prevented by the rib 62.

Thanks to that arrangement, the metal which flows from the ladle is strictly clean and the spout 4 is kept in proper condition.

The metal walls of the ladle are preferably pierced with air-holes 64 for the evacuation of gases likely to escape from-the inner refractory brickwork 65 at the moment 01 its initial drying. when the ladle is manufactured.

It is an advantage to have the stroke of the piston I'Ib adjustable in the cylinder lie so as to be able to adjust the importance of the flow of the molten mass at the beginning of the casting. For this purpose, an adjustable abutment sleeve 61 (Fig. 3) is screwed upon a screwthreaded extension of the cover 86 of cylinder lie, and the rod Ila is provided with a collar 98 adapted to engage with said sleeve.

Figs. 6 and 7 show a variation, intended for simultaneous feeding of two molds not shown, by means of two hoppers 5a and 5b and two troughs 8a and 6b. According to that exampleythe ladle I is fitted with two spouts 4a and 4b, opening above the tunnels or hoppers la and 51). Through the medium of pivots 99 and 10, the ladle rests on two ball-joint bearings II and 12. The hearing II is stationary while the bearing l2'is car- A screwthreaded handwheel I4, in engagement with said screw rests upon the base IS.

The casting of the pipes is conducted as explained above, the molten metal runs simultaneously from the two spouts 4a and 4b. Should one of the castings occur with a flow greater than that of the other or it the pipe obtained in one of the molds of the machine is heavier than the one obtained in the other mold, the handwheel I4 is turned in the desired direction so as to raise the ladle on the side corresponding to the casing that is too strong or to the pipe that is too heavy.

Thanks to that device, it is possible to cast two identical pipes simultaneously with the same machine. This advantage is particularly important as the production is doubled without appreciably increasing the costoi the machine or the labour engaged on the work.

In a certain case, it is advantageous to sharply stop the flow of molten metal at the end of the casting operation by causing the ladle to drop rapidly by a distance greater than the rapid rising stroke which begins the operation.

For this purpose acertain amount of play is left between the lifting parts and the braking parts of the ladle.

According to the embodiment shown in Fig. 8, the brakedrum 20 is fitted loose on the axis 16 of the toothed sector 19. The web of said drum is provided with an opening 11 in which can slide a projection 18 carried laterally by the sector l9. The drum carries two abutment screws 19a and 19b screwedon angle pieces 80 fixed to the drum 20, said screws can bear upon the lateral faces of the projection 18.

when raising thecasting ladle, the projection 18 acting upon the screw 19a, causes the drum 20 to rotate in a clockwise direction. when the casting is stopped, the sector I! is free to rotate downwardly by a certain angle, until the projec- 6 4/ tion 18 comes to rest on the screw 19b carried by the drum 20 whose rotation is prevented in that direction by the brake band. As a result thereof, the fall of the ladle is increased by a quantity proportional to the lost motion existing between the projection 18 and the screw 191;.

To enable this device to develop its entire efficiency, it is advisable to suppress all temporization of the clutch controlling the sector 19. In

this manner, the drop of the said sector, corresponding to the play existing on its connection with the brake will be added to the drop of the piston 11b, in relation to the cylinder I I0 (Fig. 1). That temporization is removed for instance, by opening wide the regulating valve 31 (Fig. 1) the elIect of which is to suppress the rising stroke ri e (Fig. 2).

The hydraulic or pneumatic control described can be replaced by any other system of control. electric for instance.

Having now described my invention what I claim as new and desire to secure by Letters Patent is:

In a centrifugal casting machine for casting pipe, a movable carriage for supporting -a pipe mold, a ladle associated therewith for pouring molten metal into said mold, means for tilting said ladle comprising cooperating quick acting fluid pressure means and slow acting mechanical means, said mechanical means including a gear sector and means for driving same, a rod having a fluid responsive cylinder therein comprising said quick acting fluid pressure means, said rod connecting said sector with said ladle. fluid actuated means to operatively connect said gear sector to said driving means, a control means, means on said carriage for actuating said control means upon movement 01' said carriage towards said ladle to actuate said fluid pressure means to initiate tilting of said ladle and to operatively connect the fluid actuatedmeans to said gear sector to actuate the latter, and means for maintaining the pressure in the fluid pressure cylinder while the mechanical means is simultaneously actuated to continue the tilting as soon as said initial tilting is begun.

JEAN ALBERT CAVALIJER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,088,293 Norris Feb. 24, 1914 1,089,139 Lummis Mar. 3, 1914 1,146,573 Jacobs July 13, 1915 1,693,654 Moore et al. Dec. 4, 1928 1,701,530 Daniel Feb. 12, 1929 1,749,083 Morris et a1 Mar. 4, 1930 1,815,093 Bignami et al. July 21, 1931 1,861,742 Hand June 7, 1932 1,959,334 Carrington May 22, 1934 2,094,736 Cofley Oct. 5. 1987 2,429,145 weasel Oct. 14, 1947 FOREIGN PATENTS Number Country Date 340,129 Great Britain Dec. 24. 1930

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