US1846995A - Method of casting pipe - Google Patents

Description

I Feb. 23,

Filed o tv 23, 1929 8 Sheets-Sheet 1 Bnnentdr Feb.23,1'932. DBDMCK 1,846,995

METHOD OF CASTING PIPE Filed Oct. 23, 1929 8 Shee1:sShe1:.?v

nnentor (IttomegS.

Feb. 23, 1932. v D B, DlMlck 1,846,995

METHOD OF CASTING PIPE Filed Oct. 25, 1929 8 Sheets-Sheet 3 Bnnentor fwwmvha Q g attornegs.

Feb. 23, 1932 DlMlcK 1,846,995

METHOD OF CASTING PIPE Filed Opt. 25, 1929 8 Sheets-Sheet 4 Zsnnentor attornegs.

Feb. 23, 1932. Q D. B. DIMICK I I 1,346,995

METHOD OF CASTING PIPE Filed Oct. 23, 1929 8 Sheets-Sheet 5 l'mventot 88 2 2 2 1 I HA6; 1 .,q. amt,

" attorneys Feb. 23, 1 932; D. B; DlMlCK Q 1,346,995

METHOD OF CASTING PIPE Filed om. 2s, 1929 s Sheets-She et e zmmwym (Ittornegs.

Feb. 23, 1932. D. B. DIMICK 3 3 METHOD OF CASTING PIPE Filed Oct. 28, 1929 8 Sheets-Sheet 7 (IttornegS.

Feb. 23, 1932.

D. B. DlMlCK METHOD OF CASTING PIPE 8 Sheets-Sheet 8 Filed Oct. 23, 1929 Enventor Patented Feb.- 23, 1932 UNITED STATES DANIEL 1B. :onvrrcx, or BIRMINGHAM, ALABAMA Mn'rnon or CASTING PIPE Application filed October 23, 1929, SeriaINo. 401,767. i

The present invention relates to improvements in method for themanufacture of cast iron lock joint culvert pipe, and has for an 7 object the production of pipe of uniform thickness. f 1

Another object of the invention is to provide an improved method and apparatus for the manufacture of cast iron culvert pipe having locking keys for effecting a lock joint between adjacent pipe sections in which a high degree of accuracy and uniformity in the size, thickness and other dimensionsof the pipe and keys is had. p A further object or the invention isto pro- Vide an improved method and apparatus for the manufactureof cast iron culvert pipe in which a'p-ipe'having a uniform thickness of wall may be produced with a minimum expenditure of labor and power, and in which the capacity of the plant will be materially increased. j p V With the foregoing and other objects in view, the invention will be more particularly 7 pointed out in the claims appended hereto.

In the drawings, wherein like symbols refer to like or corresponding partsthroughont the several views,

Figure 1 is a top plan view of the empty flaslgshowing the component parts tomake up said flask and their relation to one an-' other, and with the spigot key chill members in place ready to receive the pattern.

Figure2 is a vertical section taken on the line 22 in Figure 1 and with the pattern shown in place. V

Figure 3 is a vertical central section of the complete flask mold with stripping plates in place ready for the pattern to be withdrawn. Figure 4is a vertical sectional view of the complete mold ready for bottom pouring of the pipe.

Figure 5 is also a vertical centralsection similar to Figure 4 modified in that the device is constructed for top pouringof the ipe. V p Figure 6 is a front elevation, with parts broken away and parts shown in sectionof a machine for molding the combined bell core and pour basin.

- I Figure 10;is also a frontelevation, with thrown in place by means of a conventiona 12-12 in Figure 11.

Figure 7 is a view similar to Figure 6, but I with the bell core pattern keys drawn back into the; mold stripping position and the completed'combined bell core and pour basin mechanically stripped or lifted from the core box section of the machine, ready to be re- "5'3 moved to its place in a flask mold.

V Figure 8 is a vertical fragmentary section of. the top portion of the flask mold with stripping plates in place and'the pattern 3,? ready to be withdrawn and showing also th'e Co lifting mechanism used in withdrawingilthe 1 patter Figure 9 is a frontelevation of the complete flask and pattern assembled on a pneumatic jarring machine. "05

parts broken away and parts shown j insection, of the complete flask and pattern assembled on a mechanically operated turn-e; table ready for the molding sand to be sand thrower molding machine.

"Figure 11 is a bottom plant ofthe im proved runner box employed.

FiguredZ-is a section taken on the line Figure 13 is a section taken 13-13 in Figure 11.

Figure 14 is a top plan view ofthe improved bell core box used'showing also the 89 bell core keys. a a p Figure 15 is a section taken on the line 15- 15 in Figure 14 with the bell core keys removed, and :1

on the] line Figure 16 is'also a sectional view takenon C95 the line 16-16 in Figure 14." 1 Referring more particularly to the dra' ings 20 designates a casting stool, which constitutes the bottom of the flask. As shown in Figures 1 and 4 the casting stool may be provided with one or more pockets 21 therein to center and hold the bottom pour gate cores, when used." The casting stool 20 is also drilled toreceive the cheek centering pins 22 and the arbor centering pins 23. The cheek is designated at 24 and constitutes the outside retaining wall of the flask, the same beingmachined to the length of the pipe mold desired. The cheek 24is providedwith a perforated flange 25 at its lower portion :therebythe pattern. 2 9:, concentrio:with the flask; v o

to receive the centering pins 22. These pins retain the cheek in proper concentric relation with the stool 20. The core arbor is designated at 26 and is provided with the perforated flange 27 to receive the centering pins 23. This arbor 26 is machined to the length of the straight bore of the pipe mold desired, i

The pins 23 are'locatedconcentrically with The core arbor '26" the center of the flask. may be provided withiwingsi 28: to; support and hold the molding sand in place in the core of the finished mold.

The pattern is shown at29, This pattern is constructed for the straight bore of the desired. pipeand also. for the outside of the hell offsaidipipeg The: topfportion -oifthe pattern 29 is extends d; to receive means for withdrawing the patternirom theifiask mold,

andv for. purpose openings 30 are provided in theiupper. extendedportion the patterns A1313]; i'sshowncastiron spigot end taperi, locking key. chills; the inside" surface of each formed to the radius.- (if-the outside offthe-patternh aleava rszisypw 'vided; initheiiiiner surface of each chilll havingth'esize and form of thedesired spigot end taper lockingkey tor-its respective: pipe pattern; The, chills 31' are :received" into recesses 33' provided in. thelsectionalf cast; iron spigot key chill rings, 34', which are securely attachedltothecasting.stoolas 'by the screws of bolts 3.5'in-such';manner and in: such relatio rtothei'center ofthe. flask a s to. .holdltheinside-surifaces. oi the. spigot keychi1ls,. and

Theparts are. such: as to hold the spigot key chills 31 in-yplaceagainst thefpressureof the molding sand after. the withdrawal of the pattern and for this purpose the; upper edgesof thech-ills 31 aresloped'as indicated at" 36whereby to deflect the pressureofthe sandoutwardly. f i Y Referring to Figures'3 anrli8, designates the outer stripping plate machined in borelto the outside diameterof the top-"or enlarged hellendofthepattern 29. The-inside stri-pping plate is represented at 38:1, This inside stripping plate zmachined on its outer diameter to the boreof the spattern. weighted: or massive cast: ironcentriri-ngplug 39-. re'st's upomthe arbor 26. w-ithinathe inner stripping ring or: plate The engaging sunfaces' of. the plug and: stripping plate 3'8 areproperly:machined and-the outside surii'a'ce Of'tlie plugBQ-is preferably tapered as shown; 'heldin p'lace'by the use of cl ampsg40 in a well known manner: 'Thetampered molding The outside stripping plate- 37'is sand-rammed in place between; the pattern 29 mid-makers represented at 41'and the sand betweenthe pattern 29. andLth-e arbor- 25 is shown at 42;; After the withdrawal? of the lower end 'o f the mold cavity 43. A runner box is shown in Figures 4 and 5 as being in place on the'flask.

g Thisrunner box is also morefparticularly illustratedlin- Figures 11 12 and 13. Therunner. box .48 may be a combinationof castliiton 'andl'steel of such form as tosupportthetempered molding sand 49, when 'rammedto shape. andsize desired to make a combined bellcore and pour basin. At. 5.01am shown the impressions made in. the. bell corev by the bell locking. key patterns, leaving, cavities. of

the size and. the. positions desired .for biello e ta a Rcierringlto. Figure 5,51 designates the thin passage cavities :molded} into the combination bell core-andrpou'r basin, said pas- .sagesleadngftrom the pour basinf45} torthe upperjendiot the mold cavity, 43. This. form -i's usedwhere the-moltenlinetal'isintroduced to the upper en'd'otlthegciavity 43.

r The dry'sandgate cores 52 are placedinthe cavities orpockets' 2110f the-castingstool 20 whenever the moltenmetal is to be poured into the bottom of themold; cavity' 43, as shown'in'Fi'gure.4;--

Now therunner 100,248 andits core'areprepared upon-themachine shown in Figures 6 and 7. This machine includes in its construction 'a core box 53, which core b'ox'ismore particularly shown in Figures 14, 1'5 and16. The'inside'of the core box is machinedto the size and shape of the bell'co're desired. A

flanged 54- is provided onthe core box to center the running: box 48. The core box slidably supports the tapered locking keypatterns'55forthe bell' core. These key patterns 55 are niounted'for radial'sliding movement in the core box and crank handles 56 are provided for shiiting'the key patterns 55 back' and' forth, such. handles 56 being pro-- vided" with threaded shafts 57, which engage through'threadedopenings in portions 58 of the-hey patterns, the threaded shaft being held against longitudinal motion by the end collars 59,;b'ut, of course, being free to be ro-- tatedi "The bottom or table 60 for the runsame and iscarried by thespider .61.

"The supporting legs 62 for the core-box are erected upon'the bedlplate 63 of themachine-L This bedplate supports a hydraulic or other cylinder 64 having'theiplunger- 6'5 ner boii isadapted to receiveand support the therein coupled to the plunger 'rod' 66 vto which the spider 61 is aiiixed- The upperpattern hooks which are carried by the chains 72 and 73. Hold-down lugs 7 1 are welded or otherwise secured to the pattern hooks 71.

A wooden bridge 75.is provided with legs 76 which rest. on the inside stripping plate 38. p

The bridge is adapted to receive vertical pressure from the lugs 74 as hereinafter described.

Referring to Figure 9, 77 designates a conventional compressed air jarring machine or jolter being, shown placedin a pit 78 and projecting through the pitfioor 7 9. The flask is shown as placed upon the jarring machine.

In Figure 10, 80 designates a turntable for receiving the flask. This turntable projects through the pit floor 81 and is caused to turn by electric motor power through appropriate gearing, 82 showsa ramming. unitof, a conventional sand throwing, molding and ramming machine, commonlyknown as afsand a ring gear 83 and on diametrically opposite sides the ring gear is engaged by pmions 8 1 which are driven through reduction or other gearing 85 of a conventional form from separateelectric motors 86. The purpose is to apply power to rotate the massive turntable 80 and its stupendous Weight simultaneously at'diametrically opposite points of the circle which avoids binding inthe gearing, makes the. task of rotation easier, and simpler, re- 1 duces wear 1n theparts, and the consumptlon.

ofelectric current. i

' In the use of the device, referring to Figures 1 and 2, the casting stool 20 is carefully bored so that the openings for the pins 22 are equidistant from thecenter. In like manner the inner pins 23 for the arbor are also equi-distantfrom the center of the casting "Care'is also taken in the formation of the cheek 24 to machine it so that itvwill be concentric and properly receive the pins 22,

whereby, such cheek 24 is accurately concen trio with the casting stool. The corearbor 26 is also machined carefully and extends upto the bell line. Care must be taken to have the arbor 26 concentric both with the casting stool 20 and with the flask'or cheek 2 1. The wings 28 on the core arbor 26 are for the purpose of supporting the sand in the core and V the. arbor is preferably made with the barrel tapered, and withthe small end down to facilitate removal from the pipe. The sectional spigot key chill rings 34 are bolted to the upper surface of the casting stool 20, and are so centered that, when the spigot key chills 31 are in place, the inside curved surfaces. of the chills 31 form sections of a circle concentric with respect to the vertical axis ofthe casting stool and of the same radius as that of the outside of the pattern 29. The pockets 33 in the rings 34 will restrain the chills 31 from movement in a horizontal plane. Asthe sand is rammed down againstthe beveled upper portions of the chills 31, they are made to press closely against the pattern 29'.

' The cavities 32 in the chills form' mold cavities of the exact size and shape of the spigot locking keys desired.

The casting stool, cheek, core arbor, chill 7 rings and chills, together with the centering pins make up a complete flask. When the l/Vhen the flask is being assembled for a size and weight pipe requiring bottom pouring of the metal, dry sand gate cores 52 as shown in Figures 1 and i are placed in the pockets 21 in the casting stool 20, said cores being so placed that the small gate cavities-l7, through which the metal is to enter the-pattern cavity, are concentric with and will be covered by the :p'attern during ramming of the sand. WVhen the flask is assembled for a size and weight of pipe requiring top pouring, these pourygate cores 52' are omitted, and thecastlng stool pockets 21 filled level full of sand, or a casting stool is used of the same form the gate core pockets eliminated.

Themolding operation is started by placing a complete flask on the table of a molding machine. The pattern 29 is then lowered into the flask, being centered with respect to the flask andmolding machine by the spigot key but with chills 31 and they in'turn by the .chillrings 7110 3 1 fastened to the casting-stool.

It has been found that certainsizes and weights of pipe may be made better when the tempered -molding sand is rammed on a jarring machineor jolter such-as shown in Figure:9. In this method, with theflask and pattern in place, togetherwith the pattern for the gate 44 shown inFigure 4, when the mold is to be 'bottom poured, tempered molding sand is shoveled or spouted into the space be tween the cheek and pattern and into the space between the core arbor and pattern.

The conventional jarring machine or j olter is so made that when compressed air is allowed toflow into the machine, the piston and table attached thereto, together with theflask and sand, are caused to be jarred or jolted and the sand thereby rammed.

Certain other sizesand weights are better molded by the sand slinger method shownin Figure '10. In thismethod the flaskfand pattern we placed, as betfiona in a :centered position one tuintalble'f80.

Y This table "is driven :tzhroughth'e reduction gears 185 by the electrical "motors 86. The

table ris'thuscaused to rotate and the flask and pattern are caused to rotate therewith true.

with the axzis of rotation f the turntable.

the table, flask and pattern,.-are revolv iiirgesand is thrown by the sand slinger282 into jzthe'zsp'ace between the cheek and pattern and 7 between the core arboiuand pattern with such ifionce that the sand rannned to the density desined. fl

Either the bottom pour or top pour methods as gating the mold may :be used with eitherolter or sand s'lirrger methed -of ramming'the sand in the flask.

iuponcompletion of the above filling and ramming of the flask mold, the sand outside the pattern is leveledeven with the top of the :cheek '24 .and the sand insidethe pattern is le-veted even with the top of the core arbor 26. The inside and'outside stripping .plates 37 and 338 are then :put in'place, the outside stripping plate 37 being clamped to the check 24. The

centering plug 39'isaalso put inplace. it will :be remembered that the ontside o'f the plug 39 'istapereda-nzd thelarge st diameter is the same .asthe lboreot the inside-str pping plateSS.

. As the pattern '29 is machined with inside and outside diameters concentric, and as the The hooks 71 are engaged in theopenings in theupp'er end of the pattern 29 and the lugs 7 4 rest upon the bridgef75. Lifting action'by thecra-ne -acting on. ring 7 6, exerts an angular npward pullon the grab hooks 71. The lifting-strain isexerted on straigh'tlines through the chain 72 and 73, but, because of the form of the triangular or wedge 1ugs'74c, the grab hooks? 1 will be prevented from taking a position in al-inement with the lengths of the chains '72 and 73. The'lifting'strainthereby j exerts an inward circular force on the grab hook-$ 71 around the center of-the lower circular'hook partas an axis. This-circular force is resisted by the downward pressure of the lugs 74 against the bridge 7 5.

With this appliance the core and inside stripping plate 38 are held down while the 7 pattern is withdrawn a suflicient distance to break the static friction between the bore of fthepatternand thesand-of the core. By the time the pattern is lifted a suificient distance to allow the lug'74 to clear the bridge "75: the

core box'53.

eas es friction lbetween the p atteni-bore :amdtthezcore is so -reduced that there is no possibility of this friction being enough sto -lift the core against gravity with :the pattern"as it is further withdrawn.

After the pattern'29'is completely removed from the mold,the stripping plates '37 and 38 are likewise removed. Theeentering pl-ug :39 is, however, left in place. Being 0f Inassive design the centering plug .39 will :not move during any-careful handling of 'the mold and will remain central with "the pattern impression .by virtue :of its mass alone. The completed flask mold is removed from the molding machine and placed onthe pouring floor ready to receive the combined bell :core and pour basin48'.=

This zbelil core and pour separately from the flask in the machine shown in Figures 6 and '7. The'core box is machined to give the shape and size of the bell core desired and hasrecesses .87 machined in its upper surfaceto receive the ibellloohing lrey patterns '55. r p v- 1 This core box is shown in 'Figures 14, 15 and 16; "The heypattern-s 5'5' 'are held in angular relation one with the other but are free to slide toward and away from the center ofthecore box. The projectinglends of these 'keyapatterns are machined to' the'size and shape of the bell locking' keys desired. By rotating the cranks 56, through the threaded engagement of the shafts 57 with the lugs 58,

the-key patterns may be advanced or retracted and thus moved toward :or away from the center of the core box on radial lines. The outer surface of the inner ring of the core boxis machined toffit the 'boreof therunner box l8, which in turn is bored' to fit'thie largest outside diameter of the centering plug 39. The runner box is made up as shown in )Figures 11, 12 and '18 of an out-er cast. ring 88 and an inner cast ring 89 connected bymeans of steel bars -90 cast inplace. in the elevations of the bottom-machined surbasin are. formed The difference faces "9land '92 of therunner box is the difference-in' elevation of the top and bot'tomfof the bell core desired and thel i ke difierence in elevations of the top of cheek 24 an d corc arbor 265 I I I V The inside-diameter93 of the bottom'fiange of therunner box is bored to slidably the outside diameter of the inner ring 54 ofthe I T In-the molding of the 'conibined'bel-l core and pour basi'n, the bell 'key patterns' -5'5,

shown in Figures 6 and "7 are moved in by turning crank 56 until they project inside the core box 53 to the thicknessof the -keys' deest position, as shown in Figure 6.

The runner box 48 1S centered by the inner ring '54 of the core box and is supported on 'red, the core bottom plate 'being 'i-n'its lowi'ts outer ring by' theto p of 'the-core 'box"53 and on its "inner ring by the platform -OI'fCOI6 bottom ring 60. Tempered molding sand 49 is rammed in the runner box, the sand taking the shape of the bell core desired. Gates for either top or bottom pouring, as desired, are molded in the runner box and the pour basin in the upper sand in the runner box is shaped to give the molten iron an unrestricted path or" travel around to the gates evenly. After ramming the sand, the key patterns are drawn back by means of the cranks 56 to the position shown in Figure 7 leaving impressions 50 in the bell core to makethe bell locking keys. Compressed air 7 is admitted beneath the piston 65, raising the piston, the rod 66, the core bottom plate 60 and the combination bell core and pour basin, as shown in Figure 7 This combination bell core and pour basin is now ready to be placed on the completed fiasked mold hereinbefore described.

After removal of the completed bell core, the core bottom plate is lowered by gravity upon the release of the compressed air under the piston 65, thereby completing the molding cycle of the combined bell core and pour basin. a

The combined bell core and pouring basin, as molded in the runner box 48, is now placed in the completed flask mold, being centralized as it is lowered therein by the centering plug 39, thus completing a bell mold of even thickness. The completed pipe mold is now ready for pouring.

After pouring, the runner box 48 is re moved and returned to the bell core molding machine, the core arbor 26 is removed ready to be cleaned and replaced on any casting stool 20; the cheek 24 is removed ready to be cleaned and replaced on any casting stool 20, the pipe casting is removed for cleaning and finishing, the spigot key chills and chill ring,

and casting stool are cleaned, and the molding sand retempered ready for the making of another mold.

It will be noted that in all description of parts and through the explanation of the assembly of the several parts to make up. the complete mold, particular emphasis has been placed on the fixed relativity'of all compo nent parts to a common vertical axis. This common relativity assures that all parts of the mold cavity, and therefore all parts of the completed pipe, are concentric, and that outj departing. from theispirit thereof, such changes and modifications ,being. restricted only by the scope. of the following claims Whatis claimedis:

1, The 'herein 'described method for the manufacture of cast-iron pipe which consists in compacting green sandonopposite sides of a pattern in a mold flask, stripping the pattern from the flask, in a separate operation compacting green sand in a runner box to form a combined bell core and pouring basin, assembly and centering the runner box upon the mold flask after removal of the pattern,

and pouring the molten metal into the pour basin.

2. The herein described method for the manufacture of cast-iron pipe, which con-' sists in compacting green sand on both sides of a pattern in a mold flask with the bell end of the pattern up and the spigot end down, stripping the pattern from the sand to leave a pipe mouldingcavity, forming in a sepa-v the sand to produce a pipe moulding cavity,

separately forming of green sand a combined bell core and pour basin, assembling said bell core and pour basin upon the top of the mold centered by the centering device with reference to the mold cavity, and pouring the molten metal in the pour basin and thence into the mold cavity.

4. The herein described method for the manufacture of cast-iron pipe, which consists in centering a pattern within a mold flask, compacting green sand upon opposite sides of said pattern, centering a runner box centering device from said pattern, stripping the pattern from the green sand to form a pipe moulding cavity, separately forming out of green sand in a runner box a combined pour basin and bell core, placing the bell core on top of the mold centered by the centering device with respect to the mold cavity,

and pouring the metal into the pour basin and thence into the mold cavity in the vertical original upright position of the mold flask.

5. The herein described method for the manufacture of cast-iron pipe, which consists in centering a pattern in a mold flask with bell end up, compacting green sand upon opposite sides of said pattern, centering a runner box centering device from said pattern, stripping the pattern from the sand to form a pipe moulding cavity, forming in a bined bell core and pOU'r baSin' whollyout of green -sand,i ')lacing' the runner box upon the mold flask guided and ce'ntete'd by said 'cen- G5 ti ingdevi'ce whereby "the bell core will ac cur-altly take "up its position with ie'ference tb fihe mold cavity, and pouring 'the molten mfiEi1-in'the;po1ir basin in the originzil Vertioa'l upright position of the moldflask.

- I D-ANIEL B.-DIMICK.

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