US1480000A - Centrifugal pipe-casting machine - Google Patents

Description

Jan. 8 1924.

' J., R- MCWANE CENTRIFUGAL PIPE CASTING momma Filed March 23, 1920 3 Sheets-Sheet 1 ATTO RN EY 1920 3 sheets shoet J. R. McwANE CENTRIFUGAL PIPE CASTING MACHINE Filed March 23 Jan? 8 1924c J. R. M wANE CENTRIFUGAL 'PIPE CASTING MACHINE s sheets-sum s EN-roR,

I Patented Jan. 8, 1924.

UNITED: STAT S JAMES R. MOWANE, F BIRMINGHAM, ALABAIA.

CENTRI FUGAL 1"11313-CASTING MACKINE.

Application filed march 28, 1920. Serial No. 868,171.

To all whom it may amine-m: I

Be it known that I, JAMES R. MCWANE,

a citizen of the United States, residing at Birmingham, in the county of Jefferson and State of Alabama, have invented a new and useful Centrifugal Pipe-Casting Machine, of which the following is a specification.

This invention has reference to centrifugal pipe.casting"machines, wherein the pipe is formed in a suitable mold rotatable about its longitudinal axis at a sufficient speed to throw the molten metal deposited in the mold to the interior wall thereof and in suflicient quantities to produce, by distribution, a pipe with appropriately thick walls and with a bell end, and with the walls of sensibly even thickness circumferentially.

Inaccordance with American and English practice, cast iron pipe is made in twelve foot and sixteen foot lengths as standard length, It has previously been proposed to cast iron pipes centrifugally; that is, molten metal is deposited in rotatable molds and thrown by centrifugal force to the inner wall of the mold to there accumulate and cool, thus producinw a pipe without the use of a central core, the latter being open to certainobjections which it would be advantageous to avoid. However, while centrifugal casting has been attempted, the castin of pipe except in lengths which are far siiorter than the standard cast iron pipe lengths, has proven unsuccessful when attempted on a commercial scale.

By a method of pouring the molten metal and means for practicin the method, which I have devised, the ob ectiOnabIe features of centrifugal castin have been overcome, both the objectiona le features and the manner of overcoming them being set forth in my application for method of pouring metal in the formation of cast iron pipes,

and in my application for means for pouring metal in the formation of cast iron pipe, both filed as of even date herewith.

The present application relates particularly' to the casting machine itself, includ: ing the mold and means for supporting it and for directing the moltenmetal thereto.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding however, that the invention is not confined to any strict conformity with the showing in the drawings, but'may be changed and mod fied so long as such changes and modific'ations mark no material departure from the sallent features of the invention as expressed in the appended claims.

In the drawings,

F 1 is a side elevation of a centrifugal casting machine vembodying the invention and including the mold but omitting the pouring apparatus. Fig. 2 is a plan view of the machine shown in Fig. 1.

Fig. 3 is alongitudinal vertical section of the machine shown in Fig. 1 but omitting the mold.

Fig. 4 is a longitudinal diametric section of the mold and the end supports therefor. Fig. 5 is a face view of a core ring used at the spigot end of the pipe mold.

Fig. 6 1s a'sirnilar view of a core ring used at the-bell end of the mold. 7 1

Fig. 7 is a longitudinal vertical section of one of the pouring gates.

Fig. 8 is a section on the line" 8-8 of F i '3, omitting certain parts.

ig. 9 s a detail section showing the means for stopping the mold on the sup porting track in position to be secured .in

the mold rotating mechanism.

Referring to the drawings, there is shown in Figs. 1, 2, 3 and 8, a basic structure or bed 1 which may bein the form of a channel beam with bottom webs 2 serving to strengthen the beam, and on the u per surface of the beam are parallel ri ges 3 of Y triangular section serving as ways, or tracks for certain carria s forming parts of the structure and in t is respect corresponding to ordinary lathe practice.

Mounted on the support or bed 1 is a head stock A and a tail stock B desi ed to receive, support and rotate. a pipe ask or mold "C, the arrangement being such that when the flask or mold is mounted between the head and tail stocks its lon itudinal axis is substantially horizontal, and by rotating the mold with a charge of molten iron therein the hot fluid charge is made to flow outwardlyagainst the inner wall of the flask or mold to ultimately chill in conformity "nozzle 26, are lined with suitable refractory is formed a circular series of holes or perforations 11. The lower portion of'the carriage 4 carries a transverse shaft 12 extend- 'ingthrough a chamber 13 in the lower part of thecarriage, and'this shaft has fast to it a pinion 14 housed 'in the chamber .13. Fast to the bed-plate 1 between the ridges 3' and extending lengthwise of the bed-plate is a, rack 15 with which the pinion 14 is in mesh. At one end of the shaft 12 and so located as to be accessible to a workman is a hand-wheel 16 by means of which the shaft riage 18 slidable s ing of the drawings, made u of a series structed, andthese fittings terminate in il "45 wheel 21 like the carriage 4.

12 may be readily rotated and through the engagement of the pinion 14 with the rack the carriage may be readily adjusted lengthwise of the basic structure or bed 1.

The carriage 4 is held to the bed 1 by means of edge fingers 17 so shaped as to embrace the opposite edges of the'carriage 1, thereby preventing the carriage from lifting and at the same time permitting the lengthwise movement of the carriage along the bed.

v Adjacent to the carriage 4 is another caralong the bed 1, the carriage 18 being provided with a pinion 19 on a shaft 20 and the shaft having a hand- Fast to the carriage 18 is a gate or funnel 22 mounted on a support 23 bolted or otherwise secured to the carriage 18. of the funnel 22 is, in the particular showof fittings 24 but may be ,ot erwise conneck 25ionto which is made fast a nozzle termination .26. The arrangement is such that the neck 25 and nozzle 26 may pro ect substantially axiallyl through the sleeve .5

with the gate 22 standing upright- The in-- te'rior of the gate 22, fittings 24, neck 25 and material, such as sand and loam, providing a passageway along which molten metal poured into the gate 22 will readily flow to the nozzle 26 and out through the latter beyond a central opening 27 through the central opening or recess 9 defined by the flange 10.. The carriage 18 is rovided with fingers 17. like the fingers, 1i 'toguide and hold the carriage in its ad-,

of the carriage 4,

:justments.

The tail stock B has a carria e 28 with a rotatable sleeve 29 mounted t erein and held by caps 30, the sleeve being formed by an .intermediate pulley face 31 whereby a One end of the sleeve The neck anemone belt may be applied to drive the sleeve, such belt being indicated in dotted lines at 32 in Figs. 1 and 2. That end of the sleeve 29 toward the head stock has a faceplate 33 with a peripheral flange 34 and a centralized recess 35 similar to the face plate of the head stock differing therefrom in certain particulars. The carriage 28 may be placed at any chosen point along the bed 1 and there held by set bolts 36 passing through longitudinal slots 37 in the bed 1. I

()n the side of the tail stock remote from the head stock is a carriage 39 similar to the carriage 18, and provided with a pinion 41) like the pinion 19 of the carriage 18, a rack bar 41,a shaft 42 on which the pinion is mounted, and a hand-wheel 43 for rotating the shaft 42, all like corresponding parts of the carriage 18.

Extending crosswise of the bed 1 are track rails 44 traversin the bed between the head and tail stocks. .ounted on the carriage 39 is a pouring funnel 45 similar to the funnel 22, and as the mounting 45 is like that for. the funnel 22, similar reference numerals are applied except that there is added the exponent a thereto.

'lhe mold or flask C is received and rotated by the machine made up of the head and tail stocks A and B and the bed 1, and this flask or mold comprises a cylindrical shell 46 with heads 47, 48 made fast tothe ends of the shell 46 by being screwed thereon or in any other appropriate manner.

Since the pipe to be formed is, in the main, of elongated cylindrical shape, the shell 46 is similarly shaped. The head 47 is of flaring conformation to accommodate the part of the mold forming the bell end of the pipe, since the mold is designed for bell and spigot type of cast iron pipe.

The mold or flask is provided at the bell end; that is, at the end of the flask where the bell is molded, with a head core ring 49.

and the other end of the mold or flask carries a tail core ring 50, these two rings being shown separately in Figs. 5 and 6. The head core ring is provided with a circular series of holes 51 which match similar holes or perforations 11 in the flange 10. The head 49 is provided with a peripherally locatedcircular flange 52seating a peripheral flange 53 on the wideend of the head 4'4",

k ll

, mold are provided with matching bolt holes 'wall against which the centrifugal casting is performed. This'wall, indicated at 58, is made to conform in shape to the outer form of the cast iron pipe, The head core ring 49 has an axially hollow stem 59 entering the head 47 and there carrying a cor 60 to form the interior wall of the bell end of the pipe. This core 60 is formed of refractory material, such as sand and loam. and baked. The head core ring 49 about the stem 59 is provided with a groove 61 filled with baked sand 62 covering the space between the mold lining 57 and the core 60. The tail core ring has formed in it a recess 63 about the passage 64 centrally through the tail core ring 50, and this groove is filled with baked sand 65. The abutment rings 62 and 65 prevent the chilling of the metal.

' The rails 44 between the head and tail stocks and in about the upright axial plane of the head and tail stocks areeach provided with a depression 66 into which the flask or' mold C will drop' when reaching the depression. The depth of the depression is slight, say a half inch, more or less, but suflicient to serve as a temporary stop to hold the flask. In an installation or the commercial casting of pipe centrifugally, the molds or flasks are prepared in succession, and the heads 49 and are preliminarily attached to each flask, diametrically opposite bolt holes 67 the operation.

being provided for the purpose.

While in the operation of a plant, the casting of the pipes are successive and con tinuous, the course of a single mold will be followed, so far as the casting machine is concerned to give a proper explanation of reaches the casting machine, the head stock has been moved away from the tail stock by means of the hand-wheel 16 and parts conner-ted therewith and the pouring spouts 26 and 26 have been moved away from each other by means of the hand-wheels and mechanism controlling them so that when the flask or mold is stopped by the depressions 66, the flask is in line with the head and tail stocks but with its longitudinal axis slightly below the level of the longitudinal axis of the machine. New, by manlpulating the hand-wheel 16, the head stock A is moved against the bell end'of the pipe mold and forces the latter-toward the tall stock.

This causes shoulders 68 on the head 8 to engage shoulders 69von the head core ring 49, such shoulders being suitably beveled, and will also cause other beveled shoulders 70 on the tail core ring 55 to engage corre- Before the flask or moldsponding bevel shoulders-71 on the tail stock face plate 33. This causes the centering of the flask or mold in the head and tail stocks and Y a sufficient lifting of the flask to release it from the track so that it may freely rotate. When the flask has been thus lifted, the bolts 54 and 56 are passed through the appropriate bolt holes, this being facilitated by the provision of sockets 72 and 73 in the pe-- tions per minute to one thousand revolutions per minute.

While the centrifugal casting of pipe is not a new idea, th procedures heretofore proposed have been open to certain objections. Prior to this invention, the molds employed have been of a permanent nature and difficulty has been found in obtaining a suitable material to withstand the severe strainof constant casting. Again, it has been found necessary-to anneal pipe cast in permanent molds, raising the cast pipe to a high temperature in order to make the pipe machinable, even though in the effort to secure minimum chilling a special mixture of iron rich in silicon and low in sulphur has been used. On account of these and other difficulties heretofore centrifugal casting of pipe has not been done successfully on a commercial scale.

Tnaccordance with the present procedure, a temporary mold: using sand for a lining has been found to work successfully so that the lower silicon and higher sulphur irons could be used,.these being cheaper and available in greater quantities than other irons. Experience has shown that the additional cost of constantly renewing the molds is outweighed by the saving in annealing and in the use of cheaper and more available irons. The use of a sand mold for'making pipe. columns and other castings, as a combination mold and trough, is advantageous. With such a mold, the iron is poured therein while the mold is'either stationary or slowly,

revolving.v After, the iron is poured into the mold, a sufficient length of time is allowed for the metal to cease surging before the mold is revolved rapidly. If the mold is started revolving rapidly before the metal discharged about one half of its casting the ipe, revolving the mold until the metal solidifies, and immediately rolling the mold out of the machine and making especially where the gate enters the center of the head core, suchcore giving the proper shape to the socket or bell end of the pipe.

When the machine is arranged as described, the casting of the pipe, or other columnar structure, is performed by pouring molten metal through the gates 22 and in succession, each gate and the duct and nozzle leading therefrom having a lining 74 of refractory material. thickened, as indicated at 75. where the molten metal first hits it. Such metal comes from a ladle 76,

indicated in dotted lines in Fig. 7, there being a ladle 76 individual to each gate 22 aiid 45.

If the metal was poured into one end only of the mold it would flow to the other end and rebound therefro'mtoward the first end, setting up Waves which would ultimately subside, but as the metal cooled or dulled and became correspondingly sluggish, the

'waves would finally be impressedupon the pipe, making the walls of the pipe irregular. Moreover, loose sand and other debris from the mold and in the molten iron would be swept along with the advancing iron and become collected in spots so that, on cooling, such material would form weak areas in the pipe.

Even where the metal is poured in from both ends, a simultaneous pouring would cause a collection of dull metal and debris near the mid-portion of the pipe, with corresponding weakening of the pipe.

The pouring starts with the ladle at the bell end of the mold and when this ladle has contents, the second ladle is started pourin and continues discharging molten meta until its contents are. exhausted, the first ladle also continuing its discharge until but a small quantity ofmolten metal, equal to about the amount necessary to form part of the bell, is temporarily held back in the first ladle. Then the mold is started into rotation and the molten metal in the mold is thrown a some of the metal, in the centrifugallyto the outer wall of the molding cavity within the flask. Because the cavity at the bell end of the flask is of greater diameter than that of the cavity within the body of the flask, the metal is thrown into the portion of greater diameter,

thereby robbing the molding cavity immediately adjacent to the bell end of the mold of meantime filling the bell end of the cavity, thus causing a thinning of the walls of the pipe being cast. Now, the temporarily withheld portion of the contents of the first ladle, is poured into menace the nozzles 26 and 26 are withdrawnwith relation to the mold or flask. When the mold is secured in the machine, the nozzles are advanced so as to project at their discharge ends into the opposite ends of the mold.

The lining 57 of the mold, being made of sand, gives ofi steam or gases when the molten metal comes in contact with it. Therefore, the shell is provided with nu-. merous perforations 46 which permit ready escape of such steam or gases. The mold lining 1s of a temporary nature freshly made each time it is used, so far as the lining 57 is concerned and hence is not so susceptlble to war ing, cracking or distortion.

1'. lln a centrifugal casting machine, a rotatable head stock and a rotatable tail stock, pouring nozzles for both the head and tail stocks extending therethrough for delivering molten metal to a mold carried at the ends by said head and tail stocks, and means for moving the pouring nozzles axially of the head and tailstocks and independently of movement of the head and tail stocks.

2. Tn a centrifugal casting machine, a'bed or support, rotatable head and tail stocks mounted thereon, and pouring nozzles individual to the head and tail stocks and movable axially thereof to permit the mounting of a mold in the head and tail stocks and the adjustment of the pouring nozzles into and out of the mold.

3. In a centrifugal casting machine, rotatable head and tail stocks having means for the attachment of a mold thereto for rotation, and pouring means individual to the head and tail stocks and extending therethrough and adjustable lengthwise of the head and tail stocks to bemoved into the mold and withdrawn therefrom.

4. In a centrifugal casting machine, a basic portion, head and tail stocks mounted thereon, a track arranged between the head and tail stocks to support molds rolling on the tracks, the head and tail stocks having rotatable parts forming carriages individual to the head and tail supports to which the ends of the molds may be secured, and

stocks and each carrying a pouring gate and 5. lln a centrifugal casting machine, a

mol and means for movin material thickened where su basic member, ahead stock mounted on the basic member and adjustable len hwise thereof and provided with means or the attachment thereto of one end of a pipe mold, a pouring nozzle associated with the head stock to project therethrough for 'delivery of molten metal to the interior of the the pouring nozzle axially of the head stoc into and out of the mold. Y

6. In a centrifugal cas'tingmachine, a basic member, a tail stock mounted on the basic member and provided with means for the attachment thereto of one end of a pi e mold, a pouring nozzle associated with t e tail stock to'project therethrough for delivery ofmolten metal to the interior of the mold, and means for movin the pouring nozzle axially of the tail stoc into and out of the mold.

7 In a centrifu al casting machine, a sup-.

port for a rotata le mold, pouring means associatedwith the end portions of the support, and gates also associated with the end portions 0 the support and arranged to discharge into a mold mounted on the support, the gates each having a linin of refractory jected to the impact of the molten material.

8. In a centrifu al casting machine, a bed,

head and tail stoc s thereon, a track traversing the bed between the head and tail stocks for receiving and directing casting molds. and carriages associated with and individual to the head and tail stocks, each carriage being adjustable axially of thefl'espective.

head and tail stocks and each carrying a delively lnozzle extending through the stock closures for the mold, each core ring profor ivery into .the corresponding end of the mold and each provided with. a pouring gate movable'with the carriage and delivering into the nozzle. 9..*In a centrlfugal casting machine, an elongated mold adapted for the centrifugalcasting of pipe and the like, said mold having end core "rings defining the shape of the ends of the article to be cast and constituting vided with a central passage, and an annular groove on the inner face thereof to be filled with baked sand forming abutment rings to prevent chilling of the metal.

10. In a centrifugal castin machine, an elongated mold adapted for t 1e centrifugal casting of pipe andv the like, comprising a.

shell with an interior lining of sand shaped in conformity with the outer surface of the casting tobe formed, and end core rings defining the shape of the ends of the article to be cast and constituting closures for the mold, one of the core rings provided with an axially hollow 'interiorly projecting stem carrying a core of refractory material, and a groove in the interior of the ring around the stem filled with baked sand, and the other core. ring provided with a recess about a central passage which recess is filled with baked sand.

11. In a centrifugal casting machine, a

mold or ,flask for forming pipe or columnar form articles comprising-an elongated shell, head and tail core rings constituting closures for'the shell, head and tail stocks, one of which is movable toward the other, a track arranged between the head and tail stocks to support molds rolling on the track,

. said track bemg provided with a depression, and means actuated by the movement of one 'of the stocks to cause a lifting of the mold from the track.

12. In a centrifugal casting machine, a mold or flask for forming pipe or columnar form articles comprising an elongated shell, head and tail core rings constituting closures for: the shell, head and tail stocks.

one of which is movable toward the other,

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