US1992739A

US1992739A - Centrifugal casting

Info

Publication number: US1992739A
Application number: US656082A
Authority: US
Inventors: Frank G Carrington
Original assignee: CENTRIFUGAL PIPE CORP
Current assignee: CENTRIFUGAL PIPE Corp
Priority date: 1933-02-10
Filing date: 1933-02-10
Publication date: 1935-02-26
Anticipated expiration: 1952-02-26

Description

Feb- 26, 1935 F. G. cARRlNGToN 'CENTRIFUGAL CASTING 3 Sheets-Sheet Filed F'eb. 10. 1953 Feb- 26, 1935- F. G. cARRlNG'roN CENTRIFUGAL CASTING FledFb. l0, 1553 5 Sheets-Sheet 2' v ,TOR

ATTORNEY *I Wl l w Feb. 2 6, 1935;

F. G. CARRINGTQN GENTRIFUGAL CASTING Filed Feb. 10, 1933 3 Sheets-Sheet 3 ATTORNEY l-atentetl Feb. 2.6, 1935 t i i UNITED sTATEs PATENT oFFicE 1,992,739 cEN'rnIFUGAL CASTING Frank (l.V Carrington, Anniston, Ala., assigner to Centrifugal P ipe Corporation, Jersey City,

NL J., a corporatin of Delaware y Application February 10,1933, Serial No. 656,082 16 Claims- (Cl. 22-94) This invention relatesto the art of casting trough must also be inclined in oi'der to feed pipes and other hollow bodies centrifugally in the molten metal into the mold by gravity, ity has which molten metal is discharged into a rotatbeen customary to incline the trough and mold ing cylindrical mold from the end of a pouring in the same direction and at about the same trough extending longitudinally within the mold angle and longitudinally displace one relative `5 during relative axial displacement ot the mold to the other. Where socket pipes are being cast, and trough whereby the casting is progressively it is usual first to cast the socket or bell of the built up within the mold from one end to anpipe located at the lower end of the mold and other by means of hellcalLv deposited ribbons then advance the stream uphill toward the more l0 of metal. elevated spigot end of the mold. This allows the l0 In the mode of centrifugally casting metal pipe completed pipe to be conveniently removed from now in vogue, the pipe at the conclusion of the mold without striking against the trough. the casting operation is withdrawn substantialbecause the ,pipe must be removed from the` sockly horizontally from the mold onto a series of et end of the mold and. the socket endl is l5 supporting trussesbr skids arranged at spaced `located at the lower end of the moldand hence 15 intervals beneath the pipe.l Since the constitumostdistant from the trough after'the trough ent metal, of the pipe at this time is easily dehas completed its peuring e formed because of its high temperature, the pipe Under some circumstances it is desirable'to deis susceptible to deformation. Thus, the rela` Dart from the Conventional method of .Casting 20 tively few points along the pipe come in contact and rstcast the smooth spigot end 0f the Dine 20 with the trusses and sustain ,the entire weight and finally its Socket end. This reduces the of the pipe and tend to be pressed inwardly oonharmful elfect of the contraction stresses in the stricting the diameter or the pipe, and the pipe which result when the socket end is cast rocr or upper arcuate section or the wall of rst. These Stresses arise because the Socket 0f `the pipe also tends to sag under its own weight the pipe forms a circumferential enlargement 25 and bulge out the unsupported lateral walls of which locks Within the Secket Dertien 0f the the pipe. The pipe upon hardening, therefore, mold and causes the subsequently formed secis not of the truly cylindrical shape in which it tions of the pipe during cooling rst t0 expand emerged from the mold, and this distortion is away from the socket and then to shrink toward frequently so great as to require its rejection. it. it being understood that the pipe While 0001-' 30 An important object of the inventionis to proing first expands and then Contracts by en vide in a centrifugal casting apparatus a cradle amount dependent upon Several Ieotls. But for receiving the pipe casting as it is stripped casting the-socket end last, and hence placing from the mold, provided with flexible elements it at the upper end of the mold has necessitated at closely spaced intervals lengthwise of the pipe that it be located nearest the trough so that spe- 35 and defining a sling for resiliently and rockably cial provision has had to be made for moving Supporting the pipe. Thefflex'ible elements emeither the mold or trough out or' each' other-s brace the pipe for a substantial portion of its way in order to remove the cast, pipe This has circumference, thus distributing its weight over lwaysbeen a 'source of delay and annoyance.

a ,large mea and; aordmg lateral support for According to the present invention, I mount the walls of the pipe' The-cradle is mrt'hemmre the mold with its socket end pointed away from adapted to be rocked to move the lune into up". the trough and inclined in a direction opposite right position, resting upon its end, until the. solidication has proceeded to completion and to that of the trough By Vlrtue of this arrange ment the pipe may be built up from its smooth 45 giusfnminate the tendency to atten-on the spigot end toward its socket end while at the In the usual process ofcentrifugal casting, ln same time the Socket end of the'mold is located order that, the metal issuing from the end of in such a position as to permit the withdrawal the pouring trough will not spread out over'ftoo 0f the'DiDe Oln the end '0f the mold. furthest large an area when the stream strikes the inremoved from the troughl and thus without in- 60 terior of the mold, the mold is disposed at an terferenee from the trOugh. At the Same time inclination to the horizontal and the metal expansion and oontlaotion dimcultes are minstream is progressively displaced from the lower imized. The process o f casting described above, end to the upper end of the mold by relative axial whereby the mold.I is tilted at an inclination op- '55 movement of the vtrough and mold. Since the pos'lteto that of the trough during, casting isbe- 55 lieved to be original and constitutes a part of the invention.

The invention will be better understood by reference to the annexed drawings illustrating a preferred embodiment in which:

Figure 1 is a side elevation partly in section of the casting apparatus; Figure 2 is a plan view of the apparatus shown in Figure 1; Figure 3 is a cross-Section on an enlarged scale through the mold housing taken on the line 3-3 of Figure 2, and showing particularly the manner of supporting the mold; Figure 4 is a cross-section on an enlarged scale through the cradle on the'line 4 4 of Figure 1 and showing the flexible elements for supporting the pipe casting during andy after its ejection from the mold; Figure 5 is a fragmentary perspective showing of a portion of one of the articulated members carried by the cradle and the manner of attaching thereto the vertical arms carrying the flexible pipe-supporting elements; and Figure 6 is a diagrammatic representation of a modified form of casting support which may be alternatively employed in connection with the cradle shown in Figure 1.

Referring to Figures 1 and 2, the embodiment of the invention illustrated comprises in general three major parts namely, a trough section A, a mold section B and a cradle section C, arranged in alinement. The trough section A is composed of a pair of I-beam rails 1 pivotally mounted at one end upon pins 2 on jacks 3 at the end of the rails nearest the mold section B, which jacks may be raised and lowered by an adjusting mechanism 4. The other end of these rails is carried upon the upper ends of plungers 5 working within cylinders 6 so that admitting fluid to the cylinders by a valve, not shown, causes the rails to be swung about the pivot pins 2 to dispose them at any desired inclination. n

The rails 1 together constitute a track along which travels a carriage 7 The carriage is provided With wheels 8 engaging the rails and upon the carriage is mounted one end of a pouring trough 9, the other end of the trough .located nearest the mold section reposing upon a concave roller 10 fastened to a plate 11 extending transversely between the rails 1. For moving the trough axially into and out of the mold, there is provided a pair of

sprockets

12 and 13, sprocket 12 being mounted upon a shaft 14 driven by a motor 15 through a gear reduction mechanism 16, and sprocket 13 being fixed upon a rotatable shaft 17 extending between the rails 1. .An endless chain 18 connects the

sprockets

12 and 13 and is attached to a downwardly projecting nger 19 located on the bottom of the carriage so that movement of the chain 18 effects a travel of the carriage. The end of the trough connected to the carriage 7 defines a funnel 20, communicating with the usual channel in the trough, into which funnel molten metal is poured from a ladle 21 also mounted on the carriage. The ladle is rigidly connected adjacent its pouring edge to a shaft 22 which is journaled in uprights 23 borne upon the carriage, and is arranged to be tilted by hydraulic plungers 25 connected tocrank arms 26 on the ends of the shaft 22. Fluid pressure is supplied to operate the plungers 25 through a valve, not shown.

The mold section B comprises a cylindrical metal mold 30 conforming in diameter to the size of the pipe to be cast and being formed with. an enlarged socket at its end farthest from the trough section A, the other end of the mold being provided with a removable ring 31 constituting a ange for confining the molten metal within the mold. The mold is rotatably supported upon rollers 32 and is enclosed within a box-shaped housing 33, providing any desired water-cooling means, through the ends of which it projects a short distance. To prevent longitudinal shifting of the mold during rotation, a radial flange 49 is provided upon'the circumference of the mold engaged upon opposite sides by rollers 50` carried on bed 34. This bed, upon which the housing is mounted, is made up of a plurality of parallel I-beams, and is pivoted upon an axle 35 about which it is adapted to be swung by hydraulic plungers 36 working within cylinders 37 so as to incline the mold in a direction opposite to that of the trough when desired, as will later be explained. The mold-supporting rollers 32 are arranged in pairs upon two shafts 38'extending parallel with and upon opposite sides of the mold below its axis, as shown in Figure 3, these shafts being journaled on plungers 39, slidable Within cylinder 40 mounted on the ends of cross-ties fixed upon the bed 34. Power is transmitted to one of the shafts 38 through a chain 41 driven by a motor 42 and the two shafts are connected for simultaneous rotation by means of transmission chains 43 extending from the shafts 38 to an equalizing shaft 44, the latter being mounted upon the cross-ties situated directly below the mold.

In order that the apparatus may be used for casting pipes of different diameters, the shafts 38 carrying the rollers 32 are adjustable along converging lines which intersect at the axis of the mold whereby the rollers may engage molds of various sizes. This adjustment is accomplished by the following mechanism: Rods 45, one on each side of the mold, carry bevel gears 46 meshing with companion bevel gears 47 xed to the ends of screws 48 extending into the cylinders 40 and threadedly engaging the plungers 39 which carry the shafts 38. The two rods 45 are suitably connected together for unitary movement so that by imparting rotation to one of the rods, by means not shown, the shafts 38 upon both sides of the mold can be simultaneously adjusted toward or away from the mold axis, as desired.

The cradle section C comprises a frame 51 made up of a pair of spaced parallel I-beams 51a connected together. The frame intermediate its ends is pivotally supported upon standards 52 engaging trunnions 53 projecting laterally from the frame, whereby the frame is adapted to be swung from a horizontal position, in which its end nearest the mold sheats upon abutment blocks 54, into an upright position as shown by dotted lines in Figure 1. Fastened upon the upper anges of the I-beams constituting the frame 51 are two companion pairs of bearings 55 and 56 in which are journaled

shafts

57 and 58, respectively, extending crosswise of the frame and having pairs of

sprockets

59 and 60 keyed thereto. Endless chains 6l each composed of a series of pivotally connected bars or links 62 extend between these sprockets. The links 62 are connected together by pivot pins 63, which are extended as shown in Figure 5 and have rollers 64 rotatably mounted thereon which are engaged by the teeth 65 on the sprockets. Also pivoted upon certain of the pins 63 at the other side of the links are carriages 66 provided withrollers 67 arranged to ride upon guide rails 68 skirting the upper runs of the chains. The carriages 66 are connected by crossbars 69, extending between corresponding links of each chain and upon these cross-bars are vancing end of the pipe as of the weighted roll causes clamped arms 70 extending perpendicularly thereto and having their lower ends forked to snugly fit over the cross-bars. The arms 70 are detachably fastened to the cross-bars by means of pins 71 which pass through apertures in their forked ends and into similar apertures 72 in the crossbars. The latter apertures are duplicated at intervals along the cross-bar to permit the arms to be adjustably positioned toward or from each other.

Mounted upon the upper ends of the arms 70 are rollers 73 and between the rollers of the two arms on each cross-bar is swung a flexible element, such as a chain 74, the length of the section of chain between the rollers being sufficient to support the pipe over a substantial arc of its circumference. The length of this section is adjustable and is resiliently suspended as follows: One end of the chain is anchored at 75 onone of the arms 70. The other end of the chain is connected to a screw 76 resilientlymounted through spring 81 in a bracket 78 on the opposite arm 70. By turning the screw 76 by means of a handwheel 84, the chain can be adjusted to secure its s ug engagement with the pipe as the latter is ejec ed from the mold. Pivoted to one of the cross-bars 69 is a hook 85 adapted to engage with the adit is discharged from the mold and cause the chains 61 to move forward.

Bolted upon the ends of the frame 51 is a vertical stop-plate 86, against which the socket end of the pipe abuts after the pipe has been completely removed from the mold. A recess in the bottom of the stop-plate permits the hook 85 to drop free when the pipe strikes against the stopplate. At this time the advance of the pipe will be arrested and the cradle rocked into upright position about the trunnions 53. This rocking movement is effected by an electric motor 87 which turns a worm 88 in engagement with a segmental gear 89 fastened to one of the trunnions 53. A motor 90 connected to shaft 58 may be employed Vfor retracting the carriages 66 and their pipe supporting elements.

The pipe is stripped from the mold as follows: The trough carriage is provided upon its bottom with a transverse angle iron 92 which bears against and supports one end of a push-bar 93 extending longitudinally beneath the trough and supported at its other end upon an adjustable roller 95. A laterally offset finger 94 on the mold end of the push-bar is inserted into the shrinkage space between the ring closing the spigot end of the mold and the end of the pipe. When the motor is operated the trough carriage is moved forward carrying with it the push-bar 93 which shoves the casting out of the mold onto the series of chains 74 of the cradle.

An alternative means for mounting the movable elements of the cradle is shown in Figure 6. In this modication chains 100 are provided with carriages 101 having rollers 103, similar to those shown in Figure 5, but the chain4 100 instead'of winding over sprockets run upon a track 104. The ends of the chains 100 are united by cables 105 trained around

drums

106, 107 and 108 in the manner shown in the figure. A weighted roll 109 is suspended by a pair of belts 110 iixed at one end 111 to a stationary part of the frame, its other end being wound around the drum 107. The pull the upper run of the chain to be always drawn toward the left. The chains 100 carry upright arms 112 between which are suspended cradlechains for supporting a pipe casting just as illustrated in Figure 5. A hook 113, carried by the chain, is adapted to form an abutment against which the pipe pushes as it is ejected from the mold. The

It is, of course, not necessary that the cradlev described above be used with the form of centrifugal casting apparatus described. The cradle is just as capable of use example, in which the mold is bodily displaced relative to the pouring trough.

The operation of the apparatus will now be described when casting according to the conventional method with the trough extending within the mold slanted in'the same direction as the mold and the bell or socket end cast first. 'Ihe rollers 32 upon the bed 34 of the mold section B are adjusted by the rod 45 to accommodate a mold of the desired size, the slope of the mold adjusted through plungers 36, and the rails 1 carrying the trough carriage 7 are preliminarily adjusted to the proper height and slope by means ofthe adjusting screw 4 operating the jacks 3, and the hydraulic cylinder 6, this inclination being such that the molten metal will ow freely within the trough by gravity.. The ladle 21 is filled with molten metal while lthe carriage 7 occupies a position with the discharge end of trough 9 located at the socket portion of the mold. The mold having been set in rotation, the ladle is slowly tilted by means of the hydraulic plunger and after sufficient metal has been deposited to fill in the socket portion of the mold, the traverse of the trough will be -begun by lconnecting the electric motor 15 with shaft 14 which causes the endless chain 18 to be wound around the sprockets 13L and 14 in a counter-clockwise direction (Figure 1) carrying the carriage to the left by reason of its connection thereto.

After the pipe has been cast, the trough is removed from the mold, as shown in Figure 1 one end of the push-rod 93 is placed on the ange of angle iron 92 and its laterally bent end 94 engaged with the spigot end of the pipe. The

` track 104 `is formed with a downwardly sloping end so that final movef with other forms of centrifugal casting machines including those, for

under the urge of the with the hook 113 in position the farther end or within motor 15 is then reversed and the carriage 7 f moves slowly to the right, stripping the pipe from the mold. Asthe-socket end lof the pipe moves out of the mold it strikes the hook 85 and causes the cradle chains 74 to be brought one by one into position tosupport the moving pipe. These chains will initially be loosely suspended between the arms 70 so as to hang clear of the pipe, but as each chain is brought under the pipe an attendant stationed at the side of the cradle will turn the handwheel 84to draw the chain into snug engagement with the circumference of the pipe. When the pipe is completely clear of the mold, the' series of chains will in association constitute a sling in which the pipe will be resiliently supported by reason of the springs 81 connected to one end of the ycha The push-rod 93 will continue to shove the pipe gli,

from the mold until the socket end of the pipe strikes against the stop-plate 86 and the hook 85 drops free of the pipe. The trough carriage is then retracted and the motor 87 set in operation to swing the cradle'into uprighty position as shown in dotted lines of Figure l, the pipe resting on`its enlarged socket end. The pipe remains in this position until it has cooled sufciently to be strongly resistant to deformation after which it is removed, as by a traveling crane, to the annealing furnace.

The cradle chains 74 which support the pipe 'in horizontal position will be located suliciently close together to obviate any possibility -of deformation of the pipe under its weight while in a horizontal position. Also, since these flexible elements embrace the pipe for approximately 180 degrees, the sides of the pipe are prevented from bulging. After the pipe has been removed and the cradle rocked back to horizontal position by reversing the motor 8'7, the motor .90 will be operated to return the chains 61 to such position that the hook 85 will lie in position to engage the end of the succeeding pipe to be ejected.

When a cradle, shown in Figure 6, is employed, the operation is substantially the same. The advancing end of the pipe strikes the hook 113 and draws the chains 100 to the right on the track 104 until the pipe strikes the stop-plate and the hook rides out of engagement with the end of the pipe. After the cradle has been tilted to upright position and the pipe removed therefrom, the chains automatically return to their original position under the iniiuence of the weighted roll 109 which will havebeen raised by the winding of the belts 110 over the drum 107 during the movement of the chains to the right.

When it is desired to utilize the apparatus to cast pipe by the process in' which the spigot end of the pipe is cast first and the socket end last, 'the trough 9 is rst adjusted to the proper inclination and then the mold is adjusted by means of the hydraulic plunger 36 to an inclination opposed to that of the trough to dispose themold inthe dotted line position of Figure 1. In this position the discharge end of the pouring trough will reach to the socket end of the mold lthrough and from a position beyond the spigot end of the mold. The mold is set in rotation and the pouring end of the' trough advanced during casting..

from the spigot to thesocket end. This is just the reverse o f the conventional method. The

.mold is then lowered to horizontal position and the cast pipe ejected from the mold onto the cradle in the same manner as has heretofore been described.

I claim: l

1. An apparatus for casting pipe centrifugally comprising a rotatable mold inclined to the horizontal having an enlarged socket at the upper end, means for rotating the mold, a trough extending into the mold inclined tothe horizontal but in theopposite direction, and means for effecting relative longitudinal displacement between the mold and trough.

2. An apparatus for casting tubular bodies `centrifugally comprising a rotatable mold,

means for ejecting the casting lengthwise'from the mold, and a cradle for receiving the ejected casting, said cradle comprising a series of flexible supports spaced longitudinally of the cradle and arranged to engage the casting for a substantial distance about its circumference, said supports being movably mounted so as to travel with the casting as it is ejected.

on the stop-plate supported at its 'weaves 3. An apparatus for casting tubular bodies centrifugally comprising a rotatable mold, means for ejecting a casting lengthwise from the mold, and a cradle for receiving the ejected casting, said cradle comprising two parallel chains arranged longitudinally of the cradle, pairs of uprights carried by the chains at closely spaced intervals, flexible supports extending between said `pairs of uprights and arranged to engage the prising a series of flexible supports spaced lon-k gitudinally of the cradle and arranged to engage the casting for a substantial distance about its circumference, and means for rocking the cradle into vertical position.

5. An apparatus for casting tubular bodies centrifugally comprising a rotatable mold,v means for ejecting the casting lengthwise from the mold, and a substantially horizontally disposed cradle for receiving the ejected casting, said cradle comprising a series of flexible supports spaced 1ongitudinally of the cradle and arranged to engage the casting for a substantial distance about its circumference, said flexible supports being movably mounted so as to travel with the casting as it is ejected, a stop-plate at the end of the cradle, and means for rocking the cradle into vertical position to dispose plate.

tial distance about its circumference as it is ejected, a stop at the far end of the cradle against which the bell-end of the pipe abuts when completely ejected, and means for swinging the cradle into vertical position to deposit the pipe bell-end.

7. An apparatus for casting pipe centrifugally comprising a rotatable mold inclined to the hori-- zontal having an enlarged socket at the upper end, means for rotating the mold, a trough extending into the mold inclined to the horizontal but in the opposite direction, and means for effecting relative longitudinal displacement between the mold and trough to deposit metal from the spigot end to the socket end.

8. Apparatus for centrifugally casting cylindrical metal shapes comprising a rotatable mold, a pouring spout attached to and supported by a. carriage, means for moving mold and carriage relative to each other to helically deposit metal in the mold, and removable means carried by said carriage and adapted to engage .the casting to push the same from the mold.

9. In centrifugal casting apparatus comprising a rotatable mold and a pouring spout attached to and carried by a carriage, means carried by said carriage adapted to engage the casting, and

the pipe on end on the stopmeans for moving the carriage and the mold relative to each other to eject the casting from the mold.

10. Apparatus for centrifugally casting cylindrical metal shapes comprising a rotatable mold, spout carrying means, a pouring spout carried by said spout carrying means, means for moving mold and spout relatively to helically deposit metal in the mold, and means carried by the spout carrying means adapted to engage the casting to push the same from the mold.

1l. An apparatus for casting tubular bodies centrifugally comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, and a cradle for receiving the ejected casting, said cradle comprising a freely flexible support conformable to the casting for a substantial distance about its circumference.

12. An apparatus for casting tubular bodies centrifugally comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, and a cradle for receiving the ejected casting, said cradle comprising a series of freely ilexible supports spaced longitudinally of the cradle and conformable to the casting for a substantial distance about its circumference.

13. An apparatus for casting tubular bodies centrifugally comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, and a cradle for receiving the ejected casting, said cradle comprising a series of freely exible resilient supports spaced longitudinally of the cradle and conformable to the casting fora substantial distance about its circumference.

14. An apparatus for casting tubular bodies .centrifugally comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, and a cradle for receiving the ejected casting,

said cradle comprising a series of freely flexible supports spaced longitudinally of the cradle and conformable to the casting for a substantial distance about its circumference, and means for adjusting the supports into and out of engagement with the casting.

l5. An apparatus for casting tubular bodies centrifugally, comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, a movable member, a series of members spaced along the movable member and adapted to receive the casting and travel therewith in the direction of the length of the casting, and means on the movable member engageable by the casting during its ejection for movingthe spaced members with the casting as it is ejected.

16. An apparatus for casting tubular bodies centrifugally, comprising a rotatable mold, means for ejecting the casting lengthwise from the mold, a movable member, a series of 'exible members spaced longitudinally along the movable member and adapted to receive the casting /and travel therewith in the direction of the length of the casting, and means on the movable member engageable by the casting during its ejection for moving the spaced flexible members with the casting as it is ejected.

' FRANK G. CARRINGTON.