US2523558A - Casting device for centrifugal casting machines - Google Patents

Description

Sept. 26, 1950 J. A. CAVALLIER CASTING DEVICE FOR CENTRIFUGAL CASTING MACHINES 4 Shegts-Sheet 1 Filed Dec.

\NVENTU (i JEAN ALBERT CAvALu E c Sept. 26, 1950 'J. A. CAVALLlER CASTING DEVICE FOR CENTRIFUGAL CASTING MACHINES Filed Dec. 30. 1946 4 Sheets-Sheet 2 JE ALBERT CA A i Sept. 26, 1950 J. A. CAVALLIER 2,523,558

CASTING DEVICE FOR CENTRIF'UGAL CASTING MACHINES Filed Dec. so, 1946 4 Sheets-Sheet z Sept. 26, 1950 J. A. CAVALLIER 2,523,558

CASTING DEVICE FOR CENTRIFUGAL CASTING MACHINES Filed Dec. 30, 1946 4 Sheets-Sheet 4 (EM Maser CA INVENTOR.

Patented Sept. 26, 1950 OASTIN G MACHINES Jean Albert Cavailier, Nancy, France, minor to Societe: Pompes Noel, Liverdnn, France, a

French company Application December 30, 1946, Serial No. 719,272

- In France September 18, 1946 1 4 Claims.

1 It is well known that the centrifugal casting of pipes or other tubula objects is generally ef fected in machines comprising a feeding trough for the liquid metal which is introduced inside a mold rotating around its longitudinal axis.

In the usual machines, the said trough is in-the form of a gutter, lined on the inside with segments'oi cast-iron with a view to limit the effect of expansions and thus avoid a distortion of the trough. A trough of this type is a heavy and expensive structureand for a given exterior section of the channel, determined by the diameter of the object to be centrifugated, it allows of only a restricted output which is limited by the great thickness of the walls. Moreover, after each In accordance with the invention the casting channel is made of a single piece.

According to another feature of the invention, the channel has a cross section in the form of a crescent or the like, the opening of which is inferior to the greatest width of the channel.

Harmful distortions due to expansions and more particularly to bending stresses, which, in

existing channels call for the use of. detachable segments, are thus practically eliminated.

Moreover, for equal slope and exterior sections, the output of the channel is increased due to the smaller thickness of the walls and the sup pression of the joints between the usual segments.

The speed being greater, the casting operation is carried out more rapidly and consequently with a hotter metal.

It is also possible to provide channels having a very small outer diameter whereby pipes of very small inside diameters can be manufactured.

The channel being made of a single piece, it is possible to tilt the same laterally around a longitudinal axis whereby it may be emptied instantaneously over its entire length, of the metal that remains behind after each casting operation. In order to clea the channel, there is no need to wait until the metal is solid inasmuch curved surfaces cde and qhi.

2 as the channel can be turned over immediately after casting whilst the metal is still in a liquid condition.

Other features and advantages will be evident from the following description.

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

Fig. l is a schematic perspective view of the improved casting device;

Figs. 2 and 3 show diagrammaticall in two diflerent positions the automatic devices for controlling the rotation of the channel and the channel carrier, respectively;

Fig. 4 is a view similar to Fig. 1, after the channel has been turned over;

Fig. 5 is a cross section of the channel;

Fig. 6 is a similar section of the said channel during the course of machining;

Fig. 7 is a section of the said channel whilst being turned over;

Fig. 8 is a cross section of a modification;

Figs. 9 and 10 show diagrammatically a modification in which the rotation axis of the channel is inclined on its own longitudinal axis. As shown in Figs. 1 to 7, the casting device is used to feed cast-iron or another metal or alloy in a molten condition. inside and throughout the length of a mold which rotates inside a carriage I, said carriage can roll on rollers 2 along a rolling-track 3. The track 3, parallel to the longitudinal axis W of the mold, is inclined to the horizontal, and drops at its left end (Figs. 1 and 4). v

The casting device includes a feeding ladle 4 which is filled with molten metal or alloy by means of a casting ladle not shown. The ladle is pivoted on a horizontal axis and allows the molten metal to flow into an elbow shaped spout 6 from which the metal flows at I into the casting channel 8.

The spout 6 is secured at I to the-end of the channel. The latter is made in a single piece and taken from a commercial cylindrical bar, for example of mfld tempered Martin steel.

The outer surface 9 (Figs. 5 to '7) of this channel is cylindrical having its axis at 0; its radius is slightly less than that of the inner cross section of the pipe to be produced.

The inner face bcdefghii (Fig. ,5) of the channel groove I0 is substantially trapezoidal in cross section. It comprises two plane surfaces be and i1, joined on the one hand to the outer surface 9 by means of round surfaces ab and 77s and on the othe hand to the concave bottom ejg by two The width by at the entrance to the groove is less than the maximum width dh of the groove and preferably greater than half that width. Furthermore, the depth of the groove is such that the thickness of the bottom is greater than the thickness of the side walls. The thickness is maximum at fi,-it then decreases from 7' to dd and from I)" to M1,. It is constant between dd and co and between hit and ii; it then decreases again towards zero starting from cc"and from it.

The outline of the lateral round surfaces cde and ghi is constituted by two pairs of arcs of a circle: cd (center and de (center 0 on the one hand and oh (center O?) and hi (center 0) on the other hand. The bottom efg is an arc of a circle with center at 0 The level of the liquid metal in the channel is shown at ci.

The channel can easily be machined by planing, using a suitably shaped tool ll (Fig. 6) arranged obliquely, the profile of which corresponds to the half inner section of the channel. By effecting planing strokes in the position shown and in the turned over position, symmetrical in relation to the vertical plane MM, the slot is obtained very economically and without any difficulty.

The channel 8 and the spout 6 can turn over laterally around the longitudinal axis of the said channel which coincides with the longitudinal axis W of the mold. For this purpose the spout is provided with an extension or trunnion l2 (Figs. 1, 4) rotating in a bearing I3. A'pinion l4 keyed on the trunnion l2 engages a rack l5, carried by the piston rod it of a jack or fluid motor I] of any desired type, compressed air for instance. The jack H can be controlled by hand or preferably in an automatic manner, by displacements of the carriage I as explained below.

The spout 6 is provided with a lateral lug l1, adapted to engage a fixed stop i'l for limiting the rotation of the channel 8 around the axis W in the direction shown by the arrow F (Fig. l).

The device is completed by a removable carrier, the object of which is to provide a support for the free end of channel when the latter is fully withdrawn from the mold as shown in Fig. 4 so as to avoid bending. Said carrier comprises a supporting rod l8 upon which a grooved pulley I9, I9 is rotatably mounted. The rod i8 is secured at one end to a rotary shaft 20 whose axis is shown at WW. Said shaft is arranged in a base 20 at an angle oblique to the vertical. Furthermore the axis XX of the supporting rod [8 forms with the axis WW of the shaft 20 an angle a: (Fig. 1) eventually less than 90. It results therefrom that when the shaft 20 rotates around its axis W in the direction shown by the arrow 1 (Fig. 4), the axis XX of rod l8 describes either a plane or a conical surface whilst passing from the position of Fig. 4 to that of Fig. 1 and the sheave i9, i9 moves out of range very rapidly towards the bottom, enabling its outer flange iii to escape the channel 8.

Rotation of the shaft 20 is ensured by a pinion 22, keyed on to the said shaft and engaging a rack 23 carried by the piston rod 24 of a jack or fluid motor 25 operated by compressed air or other compressed fluid. The jack 25 can be controlled either by hand or, preferably, in an automatic manner by the displacements of the carriage I.

A device for the automatic control of both jacks l1 and 25 by the carriage I has been shown in Figs."1'to 4. For this purpose the carriage car'- ries laterally a lug 26 moving along the line Y--Y of two distributors or valves 3| and 32.

4 (Figs. 2 and 3) and adapted to engage with two V-shaped levers 21, 28 having branches 2! and 30 and controlling respectively the rotary plugs 34 Each of the plugs 34 has two ways or passages 35 and 34. Each of the distributors is provided with two diametrically opposed apertures 31 and 3| respectively connected to an inlet pipe 38 and an outlet pipe 40. The two inlet apertures 31 are in parallel on the pipe 39 and the two outlets 38 are in parallel on the pipe 40. .At right angles to the apertures 31, 38, each distributor has two apertures 4|, 42.

In the distributor 3i, the apertures 4!, 42 are connected to the jack 25 by means of pipes 43, 44. The corresponding apertures of the distributor 32 are connected in the same manner by pipes 45 and 46, to the jack ll.

The operation is as follows: when the device is in the position shown in Fig. 1, the carriage 1 moves downwards to the left along the track 3 as shown by arrow F. The ladle 4 is then tipped and the molten metal poured into the spout 6 passes along the channel 8. The level of the molten metal in the channel is limited to the line ci (Fig. 5) due to a suitable adjustment of the outflow from the ladle in relation to the cross section of the channel and to the speed of flow of the metal. The molten metal is thus poured into the rotary mold and applied by centrifugal force against the inner surface of the same.

A little before the end of the downward stroke of the carriage l, the lug 26, when at 26 (Fig. 2), comes into contact with the branch 28 of the lever 21 of the distributor 3| whereby said distributor is brought to the position shown in Fig. 3 and the jack 25 is put in communication at one end by pipe 43 with the inlet 39 for the fluid under pressure and at the other end by pipe 44 with the exhaust pipe 40. Through the rack 23 and pinion 22, the jack 25 will thus cause the shaft 20 to rotate in the direction indicated by arrow f (Fig. 1) whereby the carrier I8. I9 is brought under the channel 8 as shown in Fig. 4.

A short while before the channel 8 is withdrawn from the mold, the ladle 4 is raised either by hand or mechanically in a known manner and a little while after the channel 8 has been completely withdrawn, the lug 26, by acting on the distributor 32 as described above brings the jack i! into operation. The channel 8 is thus rotated in the direction of the arrow f (Fig. 1) until the lateral lug ll of spout 6 engages the abutment il which corresponds to a rotation of the channel. The abutment I! ensures an abrupt stoppage of the channel.

The molten metal left behind in the channel at the end of the casting operation collects at the bottom of the slot owing to the concave shape of the bottom wall. As a result of the tipping movement, it falls through gravity from said channel. If the metal is still liquid it flows away by running laterally on the lower lip of the channel. Due to the rounded surface ghi, and the perfect continuity of the inside wall of the channel, the metal cannot be held up anywhere.

If, on the other hand, the metal has already become pasty or solidified, the metal band 41 (Fig. 7) thus formed will be ejected without difliculty from the groove by pivoting as shown by arrow f around one of its edges 48 then by slipping as shown at 41 in the direction of arrow 1 on the lateral wall i9 of the channel.

In practice, detachment of the metal band 41 from the bottom em of the groove is considerably abutment I1 at the end of the rotation. If needs,

facilitated by the shock of the hg nmitt-t the be, a sharp blow can be given to the bottom of the a of the levers '21 and of the distributors. or

valves 32 and 3| and brings them-back to the position of Fig. 2 whereby the distribution is reamassepossible to manufacture channels of a. very small outer diameter and to extend, considerably, the possibility of turning out pipes of small diameter. Thus, it becomes possible to cast, by centrifugation. for instance, pipes with an inner diameter versed. The carrier I8 is moved laterally out of the way in the direction of arrow! (Fig. 4) and brought to the position of Fig. l enabling the carrlage I to rise and the channel 8 is broughtback by jack H to its normal position for casting (Fig.

1). From this it follows that once the carriage I has begun its upward stroke and eventually even I before it has reached its high position, a new casting operation can be started, the feeding basket 5 being tipped automatically by the movemen I crescentlike cross section, and to a limited filling oi. the channel to the level ci (Fig. 5), it is possible to avoid all distortions of the channel by bending stresses due to the differential expansions to which it is subjected. As a matter of fact, under the action of the molten metal, the channel is heated to a high temperature in the central zone of each wing that is to say from c to e and from g to 2', whereas the upper parts of those wings, thanks to the fact that they are not in contact with the molten metal and the bottom thanks to its great thickness, remain at a lower temperature. The two lateral zones of great expansion are thus included between zones of lesser expansion, the effects of. which are appreciably equal but act in opposite directions on the two heated zones. It results therefrom that the channel does not undergo any appreciable bending distortion on account of the temperature of the molten metal.

It is thus possible to eliminate the segments which in known channels, are provided for the purpose of preventing any contact of the trough supporting the segments with the liquid metal.

There is a double advantage in such elimination since the groove of the channel thus has a considerably increased section and, due to disappearance of the joints between the segments, the inner surface of the groove may have a perfect shape extremely favorable to a rapid flow of the molten metal.

Thanks to the rapid casting, that is to saythanks to hotter metal, the pipes or similar pieces obtained offer a distinctly improved contexture.

What is more,as a monolithic channel is much .stronger than the channels with segments previously utilized, it can be turned over without any difficulty and it is possible to evacuate the metal remaining after the casting, in a single operation and even before it has had time to become solid.

As a result, there is a great working facility and a double gain of time.

of 60 mm. and a 6 meter useful length or again pipeswith 25 mm. inner diameter and 3 meters useful length or pipes with an even small diameter still.

- The manufacture of the channel is easy, the machining being facilitated by the plane sections be and ii of the groove. A very important reduc:

tion of the cost price is thus realized.

Fig. 8 shows a modification in the channel section. In said figure, the outer and inner surfaces 9, I0 are cylindrical with axes at O-and 0 respectively. The outline of the inner surface may also be an ellipse or an oval [0" or else in the form of a pear for similar. 7 r

The advantages obtained by said variations are similar to thosegiven with reference to Figs. 1 to '7.

'In the construction shown in Figs. 9 and 10 the oscillation axis ZZ of the channel is oblique in relation tothe axis W of the mold.

The channel 8 is secured by flanges 8 (5 to the spout 6 which is provided with a lateral arm 49 secured on a shaft 50. Said shaft whose axis is shown at-ZZ is rotatably supported in a bearing 5|. The channel 8 can be turned around the said axis ZZ by means of a handle 52 keyed to the shaft 50.

The oscillation axis ZZ and the axis W of the mold cross at C and at that point of intersection, at the moment of rocking, the channel rests on a flanged roller 52. This roller is carried by arms 53 fixed on to the carriage I.

The axis VVlof the mold and the rotation axis ZZ form an oblique plane the line of greatest slope of which coincides with the axis VV.

By cooperating with a lateral abutment I! of the spout 6, an abutment I'I limits the rotation of the channel around the axis ZZ in the direction of arrow f (Fig. 9) in such a way that in the turned position shown in Fig. 10, the axis of the channel after a 180 rotation finds itself at VV' in the aforementioned oblique plane.

This solution offers the advantages already indicated in respect of the first example. Furthermore, it allows of an increase of the kinetic energy of the metal band 41 (Fig. 7) left in the channel, which facilitates itsexpulsion.

The invention is in no way limited to the methods of execution as shown and described,

In the variation of Figs. 9 and 10,'it is' obvious that ,the control could be automatic and ensured by a jack, actuated by the carriage I as in the first example. Likewise instead of having the carrier 53 secured to the carriage, a carrier able to be moved aside could be provided similar to the one in the first example; saidcarrier being arranged in line with the point .of intersection C of the axes W and ZZ.

In the first example, provision can be made for either several retractable carriers of the type described or of a similar type, located along the channel or else for a single carrier similar to the one in Figs. 9 and 10 and carried by the carriage I. In this example, the control, instead of being automatic, could be-hand-operated as is shown in Figs. 9 and 10'.

Finally, as the thickness of the walls is less,

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

1. A support for the. free end of the pouring trough of a centrifugal casting apparatus of the reciprocable with respect thereto, said support having a shaft rotatably mounted thereon about an axis oblique to the vertical, said shaft having an arm bent outwardly therefrom above said support, a sheave rotatably mounted on said arm, said arm and sheave being swingable into supporting position under said trough; means for actuating said trough support comprising a pinion fixed on said shaft, a rack meshing with said pinion, a fluid pressure means connected to said rack, a control device for said fluid pressure means operable by the reciprocable movement of said mold and means on said mold for actuating said control device during the reciprocal movements of the mold to operate said rack and pinion and swing said support into and out of supporting position with respect to the free end of the trough.

2. A discharge means for the pouring trough of a centrifugal casting apparatus of the type having a pouring trough and spout with a rotary mold reciprocable with respect thereto, comprising a support for the discharge end of the trough including a base offset from the path of the mold, an arm pivotally mounted at one end in said base, a trough supporting member on the other end of the arm and a first motor for swinging the arm about its pivot; a support for the other end of the trough comprising a bearing, a shaft rotatably mounted in said bearing and rigidly connected to the trough, and a second motor for rotating said shaft; a projection fixed to the mold and a control device for each motor having operatin elements extending into the path of said projection, whereby when the mold moves toward the trough, the first motor is actuated to remove the supporting member from the mold path, and when the mold has moved from the trough, the first motor is actuated to return the support, and whereby when the mold completes its travel, the control device for the second motor is operated to turn the trough to dump any metal remaining therein.

3. In centrifugal casting apparatus having a pouring trough and a rotatable mold relatively movable with respect to the trough to position the trough within the mold and withdraw it therefrom with the outlet end of the trough longitudinally spaced from the end of the mold, the combination therewith of a trough support for said outlet end, said support being offset from the path of the mold, said support comprising a base, an arm pivotally mounted at one end in said base and a trough supporting member on the other end of said arm, rotating mechanism connected to said arm, a motor for driving said rotating mechanism to swing said trough supporting member into and out of supporting position with respect to said trough, a projection-on said mold and a control device for said motor having operating elements extending intothe path of said projection, whereby reciprocating movementof the mold rctuates said control device to start said motor, to swing said trough support into or out of supporting position with respect to the trough according to the direction of movement of the mold.

4. In centrifugal casting apparatus having a pouring trough and a rotatable mold relatively movable with respect to the trough to position the trough within the mold and withdraw it therefrom with the outlet end of the trough longitudinally spaced from the end of the mold, the combination therewith of a trough support for said outlet end, said support being ofiset from the path of the mold, said support comprising a base, an arm pivotally mounted at one end in said base on an axis oblique to the vertical, a trough supporting member on the other end of said arm and extending therefrom on a line forming an angle less than with said axis,'rotating mechanism connected to said arm, a motor for driving said rotating mechanism to swing said trough supporting member into and out of supporting position with respect to said trough, a projection on said mold and a control device for said motor having operating elements extending into the path of said projection, whereby reciprocating movement of said mold actuates said control device to start said motor to swing said trough support into or out of supporting position with respect to the trough according to the direction of movement of the mold.

JEAN ALBERT CAVALLIER.

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

UNITED STATES PATENTS Number Name Date 1,286,555 De Lavaud Dec. 3, 1918 1,377,406 De Levaud May 10, 1921 1,521,244 Ladd Dec, 30, 1924 1,686,624 Millspaugh Oct. 9, 1928 2,095,573 Ridley et al. Oct. 12, 1937. 2,267,896 Bridewell et al Dec. 30, 1941 2,480,284 Boucher Aug. 30, 1949 2,483,808 Carpenter Oct. 4, .1949

FOREIGN PATENTS Number Country Date 180,485 Great Britain June 1, 1922

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