US1958672A - Centrifugal casting machine and method - Google Patents

Description

May 155 1934 w. D. MOQRE El AL CENTRIFUGAL CASTING MACHINE AND METHOD ori inal Filed June 4, 1928 M4 L1 4M E 52 n 1 Wan-r5 Mamet BY v ATT RNEYS.

I Patented May 15, 1934 UNITED STATES CENTRIFUGAL CASTING MACHINE AND METH William D. Moore and Walter Morgan, Birmingham, Ala., assignors to Sand Spun Patents Corporation, New York, N. Y., a corporation of Delaware Original'application June f4, 1928, Serial No.

282,718. Divided and this application Septem-- ber 11,1930, Serial No. 481,254

/ 8 Claims. (01, 22-65) This invention is an improvement in centrifugal casting machines and method, and more particularly in machines and method for producing relatively long hollow castings, such as cast iron pipes, either with or without bell and spigot ends,

in a substantially horizontal mold.

One of the primary objects of the present invention is the provision of mechanism for properly charging the molten metal into the flask or mold, while it is horizontal, or substantially Another object is the provision of a pouring trough or spout, of a character such as to'direct the metal longitudinally of the mold to the remote end thereof within a minimum of time, and

with a minimum of rebound and surging.

with these and other objects in view the invention consists in the construction and novel combination of parts fully described hereinafter, illustrated in the accompanying drawing, and pointed out in the claims appended hereto, it being understood that various changes in the form, proportion, size and minor details of construction within the scope of the claims, may be resorted to without departing from the spirit of the invention.

In the drawing forming a part hereof Fig, 1 is a. side elevation, with parts in section, of the upper part of a centrifugal casting ma- 3o chine embodying the improvement.

Fig. 2 is an enlarged detail section, of the pouring trough and associated parts.

The improvements forming the subject matter of the present invention are shown in'connection'with that type of machine wherein refractory lined molds or flasks are used, and wherein a freshly lined mold is provided for each cast.

The mold or flask is supported for rotation in a substantially horizontal position, and a novel form of delivery spout is employed to perfect the distribution of molten metal longitudinally of the mold, without requiring movement of the machine between inclined and horizontal position.

This application is a division of our prior application Ser, No. 282,718, filed June 4, 1928- now Patent Number 1,783,094, and only such parts of the machine of the prior application are shown, as are necessary to an understanding of the invention. The improved machine includes a suitso able frame 1, which is supported above a pit, not

shown, the frame being supported by the walls of the pit, and the carriage or bed 2 for supporting the flask 3, is carried by the'frame. The carriage or bed has a pair of flask supporting roller-s4, which are iournaled on the bed, the

pairs being spaced apart longitudinally, and the members of the pairs laterally. The rollers rotate on parallel axes, and they are designed toreceive the flask 3 to be poured. The flask is rotated by a suitable motor 5, and the rotation may be controlled by the automatic controlling mechanism shown and described in the above mentioned application, if desired.

The molten metal is discharged into the mold from a ladle 6 arranged in a frame 7, which has oppositely extending pairs of pins8 and 9. .A support in the nature of a bracket, indicated generally at 10 is connected with the end of the frame 1, the connection being preferably a hinged connection indicated generally at 11, enabling the bracket to be swung away from the bed when desired. 1 I

The pins '9 of the frame 7 are adaptedto-engage one set of a pluralityof sets of seats 12 in the upper faceof the bracket 10, and the pins 8 are adapted to engage limiting blocks 13 on the bracket, when the ladle is in horizontal position. An arm 14 depends from the frame 7 at one side of the bracket, and this arm has a pin 15,

which is adapted to seat in a fork 16, atone end of a strut 17, which as shown consists of two portions connected by a turn buckle or sleeve nut, thus enabling adjustment of the length of the strut.

The lower end of the strut is forked and engages a pin 18 in one end of a lever 19, pivoted at 20 to the pit wall, and the opposite end of the lever is. connected by a .link 21 with suitable mechanism, shown and described in the said prior application, for operating the ladle into tilted or normal position. The ladle normally occupies an upright position, and is tilted to the position shown in the drawing to empty the same, the molten metal being directed from the ladle into the flask or mold by means of a pouring trough or spout 22. I

The bottom of this spout is so inclined that just enough impetus is imparted to the flowing metal to carry it to the remote or motor end of the flask in a stream of substantially uniform cross section,

with very little. or no rebound or surging. The

impetus imparted to the moltenmetal by the in-- clination of the pouring spout is relied upon to obtain longitudinal distribution, and the inclination is calculated in accordance with several factors, such as the length of the pipe, whether or not the pipe is of the bell and spigot type, and the character and constants of the molten metal.

It has been found in practice, that with a metal of a certain fluidity, and with a known length of f in casting pipe of sixteen foot length of the sevpipe. the intim i n of h summer be so eelten metal at one end of a rotating mold while culated that the inflowing stream will reach the bell or motorend of the flask within a selected 7 time, with very little rebound, such as would cause surging and disturbance of longitudinal distribution. The longitudinal distribution -.may be facilitated by so arranging the bed that the flask is slightly inclined toward the motor .end. The

from the centrifugal motion or spinning of the noted that the flask.

Referring to Fig. 2, it will be bottom 23 of the trough or spout isprovided with insets 24 and 25 of refractory materiaL-at the point where thestream of metal from the ladle strikes; These insets are removable, ,if desired for any purpose, and materially lengthen the life of the trough, while at the same time insuring that the inclination of the bottom will remain constant. The improved charging mechanism is adapted to be used with the apparatus forming the subject matter of our above mentioned application for patent, but it is apparent that it might be used with other suitable apparatus if desired.

The bottom of the spout, that is, the surface over whichthe molten metal flows from the tilting ladle to the mold, is formed on the arc of acircle, so that the direction of the flow of the metal from the ladle is gradually changed from substantially vertical to something near horizontal, without disturbance of the even uniform flow of the metal. Furthermore, by providing a tilting ladle operated in the manner described, the metal is fed gradually andin a uniform stream to thespout, the cross section of the stream from the ladle being substantially the same from the a -moment when discharge begins until it is ended.

,The arrangement of the ladle is such that the head of the metal discharged is substantially the tom.

same from the commencement to the end of the operation, and this is a feature of importance; in connection with the inclination of the spout bot- The impetus imparted to the molten metal is such as torcause it to reach the remote end ofthe mold as quickly as possible without substantial rebound, and to attain a uniform level as quickly as possible} It will be apparent that the sub- .stantialabsenee of rebound and surging facilitates casting operations, an inclined surface for the spout formed on the arc of "a circle having a 'two'joot radius very nicely fulfills the-conditions eral diameters. That is, the ratio between the length of thepipe to be cast and the radius of the circle upon which the incline is formed, is

eight to one when casting pipes of'16 feet in 'length. This'ratio will vary slightly with the length r. the pipe and with the characteristics 7 ofthemetal. The more fluid the metal the less incline needed hence greater the radius, and the j which consists in introducing the charge of molit is substantially horizontal with impetus just sufllcient to cause the metal to flow to the opposite end of the mold without substantial rebound, and to cause said metal to lie on the bottom thereof in a mass of substantially uniform cross section prior to the centrifugal application of'the metal to-the mold wall.

" 2. In apparatus for centrifugally casting pipes,

-mechanism for introducing a charge of molten metal into one end and lengthwise of a substantially horizontal; refractory lined flask or mold, including a spout having its bottom formed on an arc'of a circle, the radius of said circle being with respect to the length of the pipe to be cast substantially in the ratio of one to eight units of measurement, saidspout being inclined at an angle sumclent to effect flow of the metal through the mold from end to end without substantial rebound and in a stream of substantially uniform cross-section.

3. Incentrifugal casting, mechanism for -introducing a charge of molten metalinto one end and lengthwise of a substantially horizontal refractory lined flask ormold', including a spout having the bottom thereof inclined at an angle such that impetus longitudinal of the moldwill be imparted to the metal just sumcient to causeit to. reach the opposite end of the mold and said angle being calculated from length of mold and fluidity of metal in inverse and direct'ratios respectively.

4. The method of casting hollow metal bodies centrifugally in a refractory lined flask or mold, which consists in introducing the. charge of mol-. ten metal into one end-of a slowly rotating mold while it is substantially horizontal with impetusjust sufllcient to cause the metal to flow to the opposite end of 'the mold without substantial rebound and tocause said metal to lie on the bottom thereof in a mass of substantially uniform cross section prior to the centrifugal application of the metal to the mold wall, and then quickly accelerating the, speed of rotation of the mold to apply the metal to the inner wall thereof centrifugally.

-5. The method of .casting hollow metal bodiesl25 .centrifugally in a refractory lined flask or mold,

which consists in charging the molteniron into one:end of 'aslowly rotating mold while it is substantially horizontal over a surface inclined inaccordance with. the length of the mold and g the characteristics of the molten iron, whereby impetus is imparted :to the advancing stream of molten iron just sufllcient to cause it to flow to the opposite end ofthe mold without substan tial rebound and tolie on the bottom thereof in a mass of substantially uniform cross section prior to the centrifugal application of the metal to the mold wall, and then quickly accelerating the speed of rotation of the mold or flask to cantrifugally apply the metal to the inner ,wall

thereof. H I

combination, a refractory-lined flask andmeans for supporting the same for rotation in a substan- 6. In acentrifugal casting machine and in tially horizontal position, means for rotating the cluding a spout having the bottom thereof inclined at such an angle with relation to the length and position of the flask that the impetus imparted to the molten metal flowing over the spout into the flask is such as to cause the metal stream to reach the remote end thereof without substantial rebound, and means for accelerating the speed of rotation of the flask to centrifugally apply the metal to the inner wall thereof.

'1. In apparatus for centrifugally casting pipes of approximately sixteen feet in, length, mechanism for introducing a charge of molten metal ,into one end and lengthwise of a1 substantially horizontal refractory-lined flask or mold, including a spout having a portion of its bottom positioned at an inclination corresponding substantially to the ar of the segment of a circle havinga 2' radius d operating to deliver the metal stream to the far or remote end of the mold or flask without substantial rebound, and in a stream of substantially uniform cross section.

8., In centrifugal casting and in combination, a refractory-lined flask or mold and means for rotating and supporting the same for rotation in a substantially horizontal position, mechanism for introducing a charge of molten metal into one end and'lengthwise of the mold or flask while it is so supported, said mechanism including a spout having the bottom thereof on an incline corresponding substantially to the are of a circle out substantial rebound or surge, and means for then accelerating the speed of rotation of the mold or flask to apply the metal to the inner wall thereof. v

a WILLIAM- D. MOORE.

WALTER MORGAN.

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