US3565157A

US3565157A - Machine for automatically cutting vertical castings and swinging away the portion of the casting which has been cut off

Info

Publication number: US3565157A
Application number: US814487*A
Authority: US
Inventors: Pierre Peytavin; Louis Babel
Original assignee: CIVILLE D ETUDES DE CENTRIFUGA
Current assignee: CIVILLE D ETUDES DE CENTRIFUGA; SOC CIVILLE D'ETUDES DE CENTRIFUGATION
Priority date: 1969-01-22
Filing date: 1969-01-22
Publication date: 1971-02-23
Anticipated expiration: 1988-02-23

Abstract

A machine for automatically cutting off and swinging away sections of metallic castings as said castings are being continuously formed by a rotary vertical casting device, said machine comprising a cradle mounted to swing about a horizontal axis and adapted to receive said casting when said cradle is vertical, means for expelling said casting when said cradle is horizontal, cutting means positioned above said cradle, means causing said cutting means to travel downwardly with said cradle while said casting is being cut, and means for successively actuating said cutting means when swinging said cradle.

Description

United States Patent Inventors Pierre Peytavin Aulnoye-Aymeries;

Louis Babel, Sauvigny-Les-Bois, France 814,487

Jan. 22, 1969 Feb. 23, 1971 Societe Civille DEtudes De Centrifugation Feb. 12, 1965, Dec. 30, 1968 France 5,307 and 182,104

Continuation-in-part of application Ser. No. 526,448, Feb. 10, 1966, now abandoned.

Appl. No. Filed Patented Assignee Priority 2,806,263 9/1957 Hogan 164/263 2,898,650 8/1959 Fredriksson et al. 164/282X 3,143,776 8/1964 Ball 164/282X 3,200,456 8/1965 Harter et al l64/282X 3,220,068 1l/l965 Geisen l64/263X 3,237,251 3/1966 Thalmann 164/282X 3,238,577 3/1966 Treadway et al. 164/282 3,375,862 4/1968 Boitchenko et al. 164/263X 3,461,951 8/1969 Szentaszloi et al 164/282 3,487,876 l/l970 Bucci 164/263 Primary ExaminerCharles W. Lanham Assistant Examiner-John E. Roethel Attorney l-lolcombe, Wetherill & Brisebois with said cradle while said casting IS being cut, and means for successively actuating said cutting means when swinging said cradle.

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PATENTEUFEB23 l97| SHEET 0F 9 INVEN r025 PIERRE- PEYm VIN Lou/5 BABEL PATENIED' m: .97.

n I I o IN VE N TOPS PIERRE Perm vm/ Laws 5455/.

' vwaw SHEET 8 BF 9 INVENTORS PIERRE Perm w/v [00/5 BHBEL ATTORNEY MACHINE FOR AUTOMATICALLY CU'I'I'ING VERTICAL CASTINGS AND SWINGING AWAY TIIE PORTION OF THE CASTING WHICH HAS BEEN CUT OFF This application is a continuation-in-part of our prior copending application Ser. No. 526,488, filed Feb. 10, 1966, now abandoned. i

This invention relates to apparatus for automatically receiving, cutting off, swinging, and ejecting sections of the metal castings produced by a continuous vertical casting machine, i and particularly by one in which the casting is rotated about a vertical axis.

There are several known processes for forming solid metallic bars, e.g. steel bars, directly from molten metal, in which processes the metal is solidified by introducing it into a cooled mold which is open at the bottom, and simultaneously extracting the solidified casting through said open bottom.

In one of these continuous casting processes, the mold is not rotated, but is vertically oscillated, and the casting is extracted vertically at the bottom by extracting rollers which are driven by any suitable means.

In another known process, to which the present invention is more closely, but not exclusively related, the mold, casting, and extracting means are rotated about the axis of the casting. This process is particularly well adapted to the production of castings of high quality, having a circular section.

The present invention relates to a device in which the casting being formed is drawn toward the bottom by extraction rollers, a section of the casting is cut off, this section is swung away, and finally removed from the machine.

The machine according to the invention comprises a cradle substantially equal in length to the section of the casting which is to be cut off and which is mounted to swing about an axis near its center of gravity, between a vertical positionin which it receives the casting being poured, and a horizontal position in which the casting is ejected.

This cradle comprises a cylinder adapted to receive the casting. An abutment which is mounted to rotate about the axis of the cylinder is located in said cylinder and supported by an ann which extends through a slot in the cylinder wall. The abutment is moved by a chain or the like which travels on two sprockets at opposite ends of the cradle.

In a specific embodiment the invention relates to a novel machine to receive a casting being formed by a continuous vertical casting machine, cut a section from that casting, swing said casting into a horizontal position, and eject said casting. This machine is of the type comprising a cradle mounted to swing about a horizontal axis and which is provided with a slotted cylinder. An abutment isslidably mounted in the cylinder and carried by a chain or the like which travels on two sprockets mounted at opposite ends of the cradle. One of these sprockets is driven by suitable means to adjust the position of the abutment. This machine is characterized by the fact that the means for cutting ofi a section from the casting is mounted above the cradle and fixed to a pair of jaws mounted to turn about the axis of the casting and capable of gripping it, said jaws being adapted to move axially with the casting.

In a preferred embodiment of the invention the pair of jaws is rotated by an electrical motor electrically synchronized with the motors which turn the mold and drive the means for advancing the casting.

In one particular embodiment of the invention the cutting of the casting is facilitated by a preheating gas jet and a cutting jet. In accordance with the invention it is advantageous to mount the preheating jet to swing about an axis inclined to that of the casting, so that it can be swung out of the way of the cutting jet when the latter is operating.

The cutting jet is pivotally mounted on levers so that it may be moved perpendicularly of the casting while remaining at a substantially constant distance from the surface of the casting.

The present invention is also directed to means for insuring that the casting has been completely cut, before the cradle is swung. Such means is essentially characterized by the fact that proportional to the vertical movement of the upper part of the casting. A second pulse generator is positioned below said point and produces pulses proportional to the vertical movement of the lower part of the casting. The pulses emitted by one of these generators are transmitted to an adder-subtractor which adds these pulses, while the pulses emitted by the other generator are also transmitted to the same adder-subtractor, which subtracts them from the number of pulses already recorded, and swinging of;the cradle is permitted only when the adder-subtractor indicates a predetermined minimum number of pulses.

In one specific embodiment the pulse generators are of the magnetic type. Each of them comprises a wheel having magnetic poles on its periphery, and a detector which emits an electrical pulse every time a magnetic pole passes by.

The pulse generator responsive to movement of the upper part of the casting may be driven by a gear wheel actuated by a rack attached to the means for cutting off the casting, whereas the pulse generator responsive to movement of the lower part of the casting may be driven from one of the sprockets on which the chain carrying the movable abutment travels.

In one specific embodiment of the invention the abutment which supports the lower part of the abutment comprises a shaft carrying a brake and attached to the rotor of a volumetric pump and to the rotor of an electric motor. An overrunning clutch is interposed between the rotor of the electric motor and that of the volumetric pump. The pump delivers to a closed circuit comprising in series a flow controller, and a one-way valve which opens only in response to an adjustable minimum pressure, and a three-position distributor which connects the volumetric pump to a source of fluid under pressure to drive it in one direction or the other.

Other characteristic features and advantages of the invention will be apparent from the following description of one embodiment of the invention, which is illustrated on the accompanying drawings, in which:

FIG. 1 is a schematic elevational view showing one embodiment of a machine according to the invention; FIG. la is a schematic diagram showing the fluid circuit which includes the volumetric pump;

FIG. 2 shows the apparatus of FIG. 1, after the cradle has been swung;

FIG. 3 is a top plan view showing schematically the device for holding the cradle in its vertical position;

FIGS. 4, 5 and 6 schematically show the machine at various stages of the operation;

FIG. 7 is a schematic perspective view, with the girder eliminated for the sake of clarity, the upper end of the swinging cradle enclosed in the lower phantom line box and the lower end of that portion of the apparatus which does not swing enclosed in the upper phantom line box;

FIG. 8 is a sectional view, taken along the line VIIIVIII of FIG. 1, as seen from above;

FIG. 9 is a schematic bottom view of the preheating and cutting jets;

FIG. 10 is a vertical sectional view through the means for supporting the jets; 7

FIG. 11 is a sectional view through the means for supporting the jaws, taken along the line XI-Xl of FIG. 12;

FIG. 12 is a sectional view taken along the line XII-XII of FIG. 11;

FIG. 13 is a schematic view showing the means for moving the movable abutment;

FIG. 14 is a diagram of the hydraulic circuit of the volumetric pump shown in FIG. 1a; and

FIGS. 14a, 14b and 14c show the different positions of the control rod of FIG. 8.

The drawings show the cradle 1 which consists of a rigid lattice girder 2 mounted to swing about the axle 3 which is preferably positioned near the center of gravity of the cradle I The beam 2 is fixed to the toothed sector 4 which cooperates with a rack 5 fixed to the piston of the hydraulic cylinder 6 mounted on the framework 7 of the machine.

The hollow cylinder 8, which has been shown in section on the drawing, is provided with a longitudinal slot 9. This cylinder is fastened inside the cradle l, which receives the casting.

An abutment provided with a rotating driving head 11 is movably mounted inside the cylinder 8. This abutment, which is guided by appropriate means, is attached to an endless chain 12 which runs over the

pinions

13 and 14 at the bottom and top of the cradle respectively (FIG. 1

The pinion 14 is driven by a worm and tangent wheel transmission which is reversible and transmits the rotation of pinion 14 to shaft 16, and vice versa.

The shaft 16 is connected to the rotor of an electric motor 17 and also to the rotor of a volumetric pump 18, and an overrunning clutch 40 is positioned between the rotor of the motor 17 and that of the pump 18. The overrunning clutch is so disposed that the rotor of the pump 18 is not driven when the electric motor 17 moves the abutment upwardly (FIG. 13), (or when the rotor drives the abutment 10 in a direction which corresponds to the ejection of the section of the casting after it has been brought into a horizontal position).

FIG. 14 shows the hydraulic circuit supplied by the volumetric pump 18.

This hydraulic circuit comprises a nonreturn valve 67 which permits the fluid to pass in the direction of the arrow f when the pressure exceeds a given value, which may be regulated by a calibrated spring, but prevents the passage of fluid in the opposite direction.

A nonreturn valve 68 is positioned in the opposite direction, in parallel with the valve 67.

The circuit also comprises a flow regulator 69, which may be of the type sold by the Brown & Sharpe Manufacturing Company under the trademark QXA-O2, which prevents the rate of flow from exceeding a given value. This device is also placed in parallel with a nonreturn valve 68.

A three'position control rod 70 makes it possible to connect the pump 18 to a source 71 of fluid under pressure and to a sump 72 for hydraulic fluid.

As a consequence of this arrangement, when the electric motor 17 turns the shaft 16, which corresponds to a right-hand movement of the abutment 10 (FIG. 2), the pump 18 offers no resistance, because of the overrunning clutch and the mechanism acts as if the pump 18 did not exist.

On the contrary, when the shaft 16 tends to turn in the opposite direction under the weight of the casting which bears vertically (FIG. 1) on the driving head 11 of the abutment 10,

I the action of the volumetric pump causes the shaft 16 to communicate to the pump 18 an adjustably predetermined torque so that it begins to turn, and (when the torque which causes the shaft 16 to rotate is reached) causes the flow regulator to restrict the speed of the shaft 16 to a predetermined limit which corresponds to the desired maximum rate of descent of the cutoff casting.

FIGS. 14a, 14b, 14c schematically illustrate the hydraulic connections which may be made by the control rod 70.

The position of the control rod 70 shown in FIGS. 14a, 14b corresponds to the step in which the casting C gradually descends, while supported by the abutment 10.

Before the casting is cut off, its speed of descent is so slow that the output of the pump is less than the maximum flow permitted by the flow regulator 69, which is accordingly inoperative.

On the contrary, the presence of the pressure of the pressure regulator 67 requires that the casting C exert a predetermined force on the abutment 10, so that the latter travels downward, while turning the rotor of the volumetric pump, which is not energized.

Once the casting C has been cut, the section which has been cut off rests its entire weight on the abutment 10, which has a tendency to accelerate its downward movement. The speed of the descent if thereafter limited by the flow regulator 69, which then imposes a maximum limit on the speed of descent of the casting.

When all or nearly all of the casting has been received by the cradle, electrical contacts close to actuate the brake 63 which stops the casting, which is then swung with the carriage, and finally ejected by the electric motor 17 which drives the abutment 10 at a relatively high speed, while the overrunning clutch isolates the pump 18 from the electric motor 17.

When the control rod 70 is in one of the positions shown in FIGS. 14b and 14c, the volumetric pump 18 is connected with the source 71 of pressure fluid, and with the sump 72. The pump may then be used to raise or lower the abutment 10, particularly when the cradle is in a vertical position. Such movement of the abutment 10 by the pump 18 is particularly useful when, during the starting of a continuous casting process, it is necessary to raise the member which blocks the lower end of the mold up to the level of the mold. At this time the abutment 10 serves the purpose of a hydraulic elevator.

Analogous hydraulic devices make it possible to slow down the hydraulic cylinder near the end of its stroke.

In the embodiment of FIG. 7, the cutter carriage 19 is slidably mounted on the framework of the machine by means of two round bars 75 which are slidable longitudinally of the framework of the machine in bearings 76, which are schematically shown.

The upper end of each bar 75 is connected to a rod 77, which is connected to the piston of a fluid-actuated jack 78. Since these jacks are conventional in construction, they have not been illustrated in detail in the drawing.

FIG. 7 also shows schematically the jacket 79 of the extractor, from which the casting being formed is received, the preheating jet 80 and the cutting jet 81, the purpose of which will be described in greater detail later. I

The

pulse generators

82 and 83 have also been shown schematically. These are respectively responsive to the speed of descent of the upper part and that of the lower part of the castmg.

FIG. 7 also shows how the pulses emitted by the

pulse generators

82 and 83 are transmitted to an adder-subtractor, in which the pulses from 82 are added at 84, while the pulses from 83 are subtracted at 85. The difference between the number of pulses from 82 and from 83 is determined at 86 by any suitable electronic means, which sends a signal over the conductors 87 whenever this difference is greater than an adjustable predetermined value.

FIGS. 8, 10, 11 and 12 show in a more detailed manner the carriage 19 to which the

jets

80 and 81 are fastened during axial movement of the casting C during cutting.

These FIGS. show the casing 19a, the upper part of which carries a bearing 88 which supports a plate 89 which may be rotated coaxially of the casting C by an electrical motor 90, through

pinions

91, 92, and transmission 93, the periphery of the plate 89 being toothed.

In accordance with one characteristic of the invention, the motor 90 is electrically coupled to the motor Ml which rotates the mold and to the motor M2 which drives the extracting means, so that the plate 89 is driven at an angular speed equal to that of the casting C.

The rotating plate 89 supports, through means not shown, a cylindrical sleeve 94 through which the casting travels. This sleeve is provided at its lower end with four windows 95 through which the jaws 96 pass. For the sake of clarity these jaws have been shown in broken lines on FIG. 10.

The mounting for the jaws is shown in greater detail on FIGS. 11 and 12.

As may be seen on FIG. 11 each jaw 96 comprises two teeth 97 positioned at right angles to each other and symmetrically with respect to the axis of movement of the jaw. These teeth 97 pass through the windows 95 in the sleeve 94 to grip the casting C.

Each jaw is suspended from the rotating plate 89 by means of a rod 98 pivotally attached at 99 to a member 100 fixed to the plate and at 101 to the jaws, and by means of two rods I02 pivotally attached at 103 to opposite sides of the jaws and at 104 to a member 105 fixed to the plate.

Moreover, each rod 102 is fixed to a toothed sector 106 which engages the corresponding toothed sector of the other aw.

As a consequence of this arrangement, the jaws may approach or retreat from each other, while remaining symmetrically positioned with respect to the axis of the casting C.

The pivot pins 101a carrying the two jaws are connected at each end through a fluid-pressure jack 107 by means of which the jaws may be separated, or simultaneously brought to bear on the casting, as desired.

A stop 108, against which an adjustable screw 109 comes to,

rest, limits the maximum separation of the two jaws.

The device which has just been described is completely symmetrical with respect to the axis of the casting, so that the entire rotating assembly may be dynamically balanced without difficulty.

As shown in FIG. 10, an abutment 94a is provided at the bottom of the sleeve 94, and is readily accessible when the machine is at rest. The inner diameter of this abutment is dependent on that of the casting being made. This abutment provides lateral support for the casting when the cutter carriage is raised to its upper position and the sleeve 94 turns at the speed of the casting, but the jaws 96 are not gripping the casting.

. The preheating jet 80 and cutting jet 81 are each mounted on the lower part of the cover 190 of the carriage 19. It will be readily seen from FIG. that the jet 80 is mounted on a cover portion 19b pivotally mounted at 19c so as to permit lateral removal of the jet 80 by swinging the cover 19b to obtain access to the jaws and their suspension means. In like manner,

' the jet 81 is mounted on a cover portion 19d which is pivotally attached at 19e to the casing 190.

The preheating jet is pivotally mounted on a shaft 114 inclined at about 60 with respect to the axis of the casting C,

'so that when the jet 80 isswung through an angle of 90 to bring it from the position shown in FIG. 10 (in which it is directed toward the casting) into a horizontal position, it automatically moves away from the axis of the cutting jet 81.

FIG. 9 schematically shows the piston cylinder 115 which, through the levers 116, swings the preheating jet 80 to bring it into the position shown in broken lines.

In a preferred embodiment of the invention, the cutting jet 8] is pivotally connected at 117 and 118 to the ends of two cranked

levers

119 and 120 pivotally connected to fixed points 121 and 122 on the cover part 19d, whereas the other arms of the

levers

119 and 120 are pivotally connected at 123 and 124 to a control rod fixed to the piston of a pneumatic jack 125. l

The cranked leverv 120 extends beyond the pivot point 124, terminating in a knob 126 which swings between two adjusting

screws

127 and 128, thus limiting the path of travel of the

levers

119 and 120 and consequently the movement of the jet 81.

In accordance with the invention, the dimensions of the

levers

119 and 120 are so selected that, as it is displaced by the pneumatic jack 125, the pointed flame of the oxygen-fueled cutting jet moves laterally with respect to the casting C while remaining at substantially the same distance therefrom.

In the embodiment of FIGS. 1-6, the cutter carriage l9 movesvertically and is guided by four angle irons 20 fixed at their upper and lower ends to the

platforms

21 and 22 of the apparatus. This carriage 19 is connected by a cable 23 passing over the pulley 24 to a counterweight 25, heavier than the carriage 19 and its accessories, so that the carriage l9 always tends to rise. The cutting means has been schematically represented at 26 and consists of a jet of oxygen, controlled in a manner which will be hereinafter explained.

A safety device 27 is schematically shown and consists of a displaceable stop supported on the platform 22, which stop positionsitself automatically under the casting while the eradle is being swung, so as to prevent the hanging part of the casting from falling if something goes wrong during its formation.

A peg 28 carried by the chain 12 is so shaped that it may be brought to bear against the bottom of the counterweight 25 to raise it. It follows that when the peg 28 is in contact with the counterweight 25, the carriage 19 moves downward at the same speed as the casting which rests on the abutment 10 of the cradle.

On the other hand, when the peg 28 is not in contact with the counterweight 25 (which occurs when the abutment 10 is positioned at the top of the cradle, or when the cradle has swung) the counterweight always descends to the bottom, thus bringing the carriage 19 (shown in the embodiment of FIGS. l-6) into its upper position in which it awaits the next cut.

FIGS. 1 and 2 also schematically show a damping device 29 which consists of a cylindrical substantially fluid-tight tube through which the cable 23 passes. This cable carries within the tube 29 a piston which partially blocks the tube so that the speed of movement of the carriage 19 is limited to a reasonable value when the peg 28 suddenly releases the counterweight 25.

The cradle is held in its vertical (FIG. 1) position by a device 30 which is shown schematically in plan on FIG. 3.

FIG. 3 shows the lattice girder 2 schematically, as well as the cylinder 8 within which the abutment 10 travels.

The cradle l is provided with inclined bearing plates 31 at the right of the holding means 30 so that the corresponding stops 32 of the holding means lock the cradle against the stationary members carried by the platform 22 when said stops cooperate with the bearing plates 31.

The stops 32 are controlled by hydraulic cylinders 33 so that they may be moved away while the cradle l is being swung.

The operation of the machine will now be explained.

FIG. 1 shows the machine at the moment at which the cradle is about to swing.

At the starting position, the carriage 19 which supports the jets and 81 is lifted to its upper position by the jacks 78. In this connection, it should be noted that it is advantageous to connect the cylinders of jacks 78 together, and to supply them simultaneously from a source of fluid under pressure through an adjustable pressure responsive valve (such as 67, FIG. 14) mounted in parallel with a nonreturn valve positioned in the opposite direction (such as the nonreturn valve 68 of FIG. 14). By regulating the loading of the pressure-responsive valve the arrangement may be made such that the pressure in the jacks 78 is only slightly greater than the pressure required to balance the weight of the members supported by the rods 7 of the jacks 78. It follows that the assembly comprising the movable parts of the cutting device is constantly urged upward by a small force, while it is driven downwardly against the resistance of this force when the jaws are clamped onto the castmg.

During the manufacture of the casting it passes through the sleeve 94, in which it is guided by the member 94a which occupies its upper position when the cutting device is in its upper position, as has already been described. The lower end of the casting rests on the abutment 10 which has already been raised to its upper position, the cradle being then latched in a vertical position, by latches 32.

When the abutment 10 reaches a point at a certain distance from the lower end of the cradle,it closes electrical contacts thus causing the jaws to'grip the casting, by actuating the jacks 107, while the sleeve 94 and the jaws continue to be rotated, as they were before the casting started.

From this moment on the casting draws the cutting device 19 downward with it. From this moment also, the

pulse generators

82 and 83 produce pulses at the same frequency since the casting C has not been cut off, and its upper and lower parts therefore travel at the same speed.

In the embodiment of FIGS. 7-12 the preheating jet 80, which is in operative position (FIG. 10), is automatically lighted by introduction of gas which begin to burn in contact with the casting and heats the casting to the temperature selected for the cutting step. Then after a certain delay of time controlled by a conventional timing device the preheating jet is stopped and swung about the shaft 114 away from the field of operation of the cutting jet 81 by introduction of pressed air in the cylinder 115. The jet 81 is then lighted as explained for the jet 80 and cuts the casting, as it is moved toward the position shown in broken lines on FIG. 9 by the jack 125, which is actuated at a suitable speed by a calibrated bore which authorizes the escape of pressed air contained in the cylinder 125 under the action of a pressure means acting on the other side of the piston.

From this moment the lower part of the casting C is free, and its fall accelerates the speed of the abutment 10. The frequency of the pulses produced by the pulse generator 83 is thereby increased, thus producing a prompt difference in the pulse count which appears at the output of the adder-subtractor, which transmits a signal through the conductors 87, to stop the cutting jet and release the jaws, which permits the cutting apparatus to rise to its upper position.

In the embodiment of FIGS. l--6, on the other hand the peg 28 releases the counterweight 25 at this moment, thereby causing the carriage 19 to rise as soon as this release has taken place.

A suitable device (such as the peg 28) acting on a switch then opens the safety device 30. The cradle is swung by hydraulic cylinder 6, which is actuated by the signal from the adder-subtractor, provided that the safety device 27 has indeed positioned itself in the path of the casting, so as to insure that it has been effectively cut and that the portion which has been cut off is in no danger of falling too rapidly.

At this moment the abutment 10 is near the bottom of the cradle, in a position which depends on the length of the section which is to be cut off, said length being itself determined by the position at which the peg 28 has been attached to the chain 12. It is thus possible to regulate the length of the casting section simply by changing the position of the peg 28.

FIG. 2 shows the machine at the moment at which the cradle has just been swung by the hydraulic cylinder 6 into a horizontal position in which the switches start the electric motor 17, which moves the abutment 10 to the right and expels the casting in the direction-of the arrow F, the casting being received by an appropriate device 34.

While the cradle is being swung, the counterweight 25 (which falls because it has been released by the peg 28) raises the carriage 19, which returns to its rest position awaiting a new cut.

When the abutment 10 reaches the right end of the cradle (FIG. 2) a switch (not shown) stops the electric motor 17 and causes the cradle to swing backward to the vertical position shown in FIG. 1.

The safety device 30 is then automatically locked in place and the safety device 27 automatically moved out of the way.

Throughout this time, the casting, which is being continuously cast by a machine not shown, continues to descend at its normal speed, which may be of the order of several meters per minute.

At the end of a certain time the lower part of the casting reaches the driving head 11 of the abutment l0 and exerts thereon a steadily increasing downward force. This is transformed into a torque exerted on the shaft 16 which turns when the torque reaches a predetermined value. The abutment therefore falls only when a sufiiciently great force is exerted thereon by the casting.

Because of this device the casting exerts during its descent a constant force against the movable driving head 11 of abutment, which force is sufficient to ensure accurate centering of the lower part of the rotating casting, since the driving head is conical if the casting is tubular and cup-shaped if the casting is solid.

In one embodiment of the invention the descent of the casting is so regulated that it exerts a force of about 100 kg on the abutment.

This characteristic of the invention is particularly important because the rigidity of the castings is in practice insufficient to prevent their lower ends from being affected by blows and unexpected movements which considerably disturb the process of continuous casting.

It will be noted that lateral impacts against the lower part of the casting are limited in the machine according to the invention by the fact that the casting is inside the cylinder 8 which has an inner diameter not much greater than that of the casting and by the fact that the driving head 11 effectively centers the lower end of the casting.

The flow regulator for the hydraulic circuit containing the pump 18 is so controlled that its flow is sufiicient for the abutment 10 to fall at a maximum speed greater than the speed at which the casting is cast. In other words, during the descent of the uncut casting only the check valve is in efi'ective operation.

FIG. 4 shows the positions of the different parts of the machine during the phase of operation which will now be described.

During this phase the abutment 10 moves downward while the peg 28 moves upward but has not yet reached the lower end of the counterweight 25.

This FIG. clearly shows that the position of the peg 28 on the chain 12 determines the moment at which this peg comes into contact with the counterweight 25, thereby initiating the next phase of operations, which consists of cutting off the castmg.

FIG. 5 schematically represents the position of the different parts while the cutting takes place.

At this stage, the peg 28 has already been in contact with the counterweight 25 for a certain length of time and has already moved the cutter carriage 19 a certain distance downward.

At the beginning of the downward movement of the cutter carrier a jet of oxygen represented by the arrow Ox begins the cutting process, which takes a certain time during which the carriage 19 and casting descent simultaneously.

When the casting is cut it rests its entire weight on the abutment 10 and thus moves it downward at a speed which is determined by the flow regulator in the circuit of the hydraulic pump 18, the operation of which has already been described.

It follows that after the casting has been cut off, the abutment 10 moves downwardly at a fairly substantial speed. It is stopped at the end of its path of travel after having been first slowed by the electrical brake.

During this time the machine has assumed the position shown on FIG. 6 (which corresponds to that of FIG. I), the peg 28 being about to become disengaged from the counterweight 25.

After this the cradle swings and the process which has just been described is repeated.

It will be appreciated that the machine according to the invention makes it possible to cut off and swing away sections of vertical castings while they are being continuously cast.

This machine may be used during the production of solid or hollow tubular castings and while it is especially designed for use with rotating casting, it may also be used to cut and swing away castings which do not rotate.

It will be further appreciated that the foregoing embodiment has been described purely by way of example, and may be modified as to detail without thereby departing from the basic principles of the invention.

Thus the cutting means shown as a cutting torch or jet of oxygen may be replaced by a high speed grinding tool or the like, driven by a motor carried by the cutter carriage.

We claim:

1. A machine for automatically cutting off and swinging away sections of metallic castings as said castings are being continuously formed by a rotary vertical casting device, said machine comprising in combination:

a cradle mounted beneath said casting device to swing about a horizontal axis near its center of gravity between a vertical and a horizontal position;

a hollow-cylinder mounted on said. cradle coaxially of the casting in said casting device when said cradle is in a ver tical position, said cylinder being provided with a longitudinal slot;

an arm slidably mounted in said slot;

an abutmentmounted on, said arm inside said cylinder to receive the weight-of said casting when said cradle is vertical and to rotate about the axis of said cylinder;

continuous traction means connected to said arm outside said cylinder; I

a pinion drivingly engaging said traction means;

a shaft drivingly engaging said pinion;

a motor connected to rotate said shaft and thereby drive said abutment through said pinion, traction means and arm in one direction along said cradle when said cradle is horizontal;

a pump driven by said shaft through an overrunning clutch so as to be driven only whenithe abutment is being driven in the other direction downwardly of said cradle by the weight of said casting when said cradle is vertical;

a closed circuit through which a fluid is driven by said pump, said circuit comprising flow regulating means restricting the volume of flow in one direction therethrough to retard the descent of said abutment, and pressure-responsive means preventing the flow of fluid in said one direction in said circuit when the pressure applied by said pump is below a predetermined minimum;

means for cutting off above said cradle a section of a casting being formed; and

control means for preventing said motor from driving said shaft when said cradle is vertical, for causing said cradle to swing toward its horizontalposition when said abutment reaches its lowermost positionand for causing said motor to move said abutment and thereby expel said section from said cradle when the cradle reaches its horizontal position.

2. A machine as claimed in claim 1 comprising a hydraulic cylinder, a rack actuated by said cylinder and a sector engaged by said rack and fixed to said cradle so that said cradle may be swung by said hydraulic cylinder.

3. A machine as claimed in claim 1 in which said cutting means comprises a tube mounted upon a vertically slidable carriage urged upwardly by a counterweight, and said counterweight is lifted upwardly by a catch attached to said traction means.

4.,A machine as claimed in claim 1 comprising a latch which locks the upper part of the cradle in place when the cradle is in its vertical position. v

. 5. A machine as claimed in claim 1 in which said cradle is prevented from swinging until a feeler has moved into a position in vertical alignment with the casting.

6. A machine as claimed in claim 1 comprising a carriage mounted to travel vertically and rotate with said casting, said cutting means being mounted on said carriage, a pair of jaws mounted on said carriage, and means for causing said jaws to engage said casting, thereby clamping said cutting means to said casting, and for releasing said jaws from said casting.

7. A machine as claimed in claim 6 in which said cutting means comprises a preheating jet and a cutting jet positioned to act successively on said casting.

8. A machine as claimed in claim 7 in which said preheating jet is mounted on said carriage to swing about a shaft which is inclined to the longitudinal axis of the casting, toward and away from said casting.

9. A machine as claimed in claim 7 in which the cutting jet is mounted on said carriage through linkage constraining it to move in a plane perpendicular to the longitudinal axis of the casting while remaining at the same distance therefrom.

10. A machine as claimed in claim 1- in which said control means comprises meansfor generating a first signal proportional to the speed of descent of the casting portion leaving the mold, and means for generating asecond signal proportional to the speed of descent of the casting portion in the cradle, means or generating a third signal representative of a difference between said first and second signals, said cradle swinging means being responsive to generation of said third signal.

11. A machine as claimed in claim 10 in which the means for generating each of said first and second signals comprises a pulse generator including a rotating wheel provided with alternating peripheral magnetic poles and means for detecting the passage of said poles.

12. A machine as claimed in claim 11 in which the rotating wheel in the first pulsegenerator is driven by a rack attached to said cutter carriage.

13. A machine as claimed in claim 1 2' in which the rotating wheel in the second pulse generator isdriven by said traction means.

Claims

1. A machine for automatically cutting off and swinging away sections of metallic castings as said castings are being continuously formed by a rotary vertical casting device, said machine comprising in combination: a cradle mounted beneath said casting device to swing about a horizontal axis near its center of gravity between a vertical and a horizontal position; a hollow cylinder mounted on said cradle coaxially of the casting in said casting device when said cradle is in a vertical position, said cylinder being provided with a longitudinal slot; an arm slidably mounted in said slot; an abutment mounted on said arm inside said cylinder to receive the weight of said casting when said cradle is vertical and to rotate about the axis of said cylinder; continuous traction means connected to said arm outside said cylinder; a pinion drivingly engaging said traction means; a shaft drivingly engaging said pinion; a motor connected to rotate said shaft and thereby drive said abutment through said pinion, traction means and arm in one direction along said cradle when said cradle is horizontal; a pump driven by said shaft through an overrunning clutch so as to be driven only when the abutment is being driven in the other direction downwardly of said cradle by the weight of said casting when said cradle is vertical; a closed circuit through which a fluid is driven by said pump, said circuit comprising flow regulating means restricting the volume of flow in one direction therethrough to retard the descent of said abutment, and pressure-responsive means preventing the flow of fluid in said one direction in said circuit when the pressure applied by said pump is below a predetermined minimum; means for cutting off above said cradle a section of a casting being formed; and control means for preventing said motor from driving said shaft when said cradle is vertical, for causing said cradle to swing toward its horizontal position when said abutment reaches its lowermost position and for causing said motor to move said abutment and thereby expel said section from said cradle when the cradle reaches its horizontal position.

4. A machine as claimed in claim 1 comprising a latch which locks the upper part of the cradle in place when the cradle is in its vertical position.

5. A machine as claimed in claim 1 in which said cradle is prevented from swinging until a feeler has moved into a position in vertical alignment with the casting.

10. A machine as claimed in claim 1 in which said control means comprises means for generating a first signal proportional to the speed of descent of the casting portion leaving the mold, and means for generating a second signal proportional to the speed of descent of the casting portion in the cradle, means for generating a third signal representative of a difference between said first and second signals, said cradle swinging means being responsive to generation of said third signal.

12. A machine as claimed in claim 11 in which the rotating wheel in the first pulse generator is driven by a rack attached to said cutter carriage.

13. A machine as claimed in claim 12 in which the rotating wheel in the second pulse generator is driven by said traction means.