US1167889A - Art of making molds. - Google Patents

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J. C. DAVIS?- ART. OF MAKING MOLDS. APPLICATION l '|LED DEC.,I6| 1912.

1,167,889, Patented Jan.11,1-916.

'15 mum WITNESSES:

r e, p

ins, the 4 ing or; the mold that a min mum length of riparian smithsreruns @FlllQE JAMES CAREY DAVIS, 05 HINSDALE, ILLINOIS, ASSIGNOR TO AMERICAN STEEL FOUNDRIES, OE CHICAGO, ILLINOIS,

A CDRPORATION OF NEW JERSEY.

ART OF MAKING MOLDS.

Specification of Letters Yatent.

Patented Jan. 11, 1916.

To all whom it may concern Be it known that I, JAMEs CAREY DAVIS, a citizen of the United States, and. a resident of Hinsdale, in the county of Dupage and State of Illinois, have invented certain new and useful Improvements} inthe Art of Making Molds, of which the following is aspeciiication.

My present invention relates in general to the art at making castings and more particularly to the production of castings in"- volving one or more of the following features: the. use of hard or temperable metal; .use in different parts of the casting of different metals or of difi erent qualities or the Smile metal; the distribution of parts of varying thicknesses; or a casting which from its prospective use must not be distorted nor vary from its predetermined form, an example of a casting for the production of which my present improvements are par ticularly available being cast steel car wheels having a tempered thread portion formed of hard manganese steel, an enlarged center formed of relatively soft steel, and a relatively thin Web.

In my foundry practice one of the main difficulties which Ihave-found it necessary to overcome in the making of cast-steel wheels, such as are produced by the process disclosed in Letters Patent of the United- State Iflo..727103 issued to me, is the relativcly high foundry loss, both of molds and of wheels, owing to cracks orfracture, the latter often accompanied by a displacement of a portion of the mold or other distortion, due. to diiiiculty in obtaining a binder for the sand which will be effective under vary-- ing operating;conditions, and more par- .ticularly a binder which may be enmloyed in such a way as to allow the. rapid production of molds which is prerequisite to the production oi cast steel wheels on a commercial basis under modern'foundry condi-- i Lions.

Llhc principal ohiects of the present inventionare the provision of an improved mold, and a method of and an apparatus oi-male meijvfhich will so hasten thedrytime must necessarily elapse between the making of the mold and the use thereof; the

production of a green sand mold having a hard, 'dry, and tough skin on the surface "without affecting interior and thence the desired porosity of the mold whereby ventilation of the mold may be maintained durmg the act of pouring wlthout in turn alffooting such hard dry surface, and th evproduction of green sand molds having a dextrin or equivalent mixture which may be rapidly dried and used practically immediately after making, together with such further objects as may hereinafter appear.

In carrying out the manufacture of cast steel wheels, and in connection therewith the making; of molds for casting such wheels, I have found that green sand when properl y mixed with dextrin'may'he used to form a mold that will dry out upon exposure to atmospheric air and harden in due course, providedja too great degree of humidity is not present in the atmosphere, the time requisite for drying being somewhat disproportionate to the humidity of the atmos phere. S'uch air drying, however. tends to harden the mold throughout and does not give the skin drying effect, which is one of the obiects which I most seek to attain,

since such skin drying does not affect the porosity of the inner'part of the mold. I have found after exhaustive experiments that when a blast of air is directed toward effect is produced and the desired supertime, without afi'ectina" the inner porosity of the mold, provided that the following conditions be carefully observed-first, that the air is supplied at the proper temperature, under the properpressure, for the roper length of time and in such a manner that it is properly distributed.

In the accompanying drawingfi i have.

illustrated, somewhat diagrammatically," a

for artificially drying the wherein-p- Figures 1 and 2 are respectively an new:

95 preferred form of apparatus employed by molds,

thereie by reguiafiimg Fag. 3 av YLW Q1? 5, tieiaii m? and ig. is a wiical secthm flamugh the m l slam ha Emmi side of Fig. 1. w 0?? h s 6:112 'ing', hat I have here indicated L0 swimming a maid member 1 hich may be suppm'ted in any convenient zsmnner as by rails, 11 :fmm the fiomr. or the 13m"- "pcse of subjeciin flue maid mem'bexi m 2. Eifif'usefl currem 1" mated Air under prwsum I employ :1 310051 01 sever 1:2, the baizmm 01? which is preferably YRS-1S; by legs, 13, slighit distance above thep of 1142 in order is permii; free exit 01? ail, Th mp, 12 0f the sever, 1:2, 1 an openim in week: a mz vpiy pi:--s, 1%, M1321; is gqr'eler abiy provided WizEL sii jcinfi E, to facilihe the E'Qifiihe penin ly M a; 0y r 15, which my be driven 1y cenvenient manner as by a be i'ii driving she pull y, 16, {see 2) [as means Em preheating the air suppiiefi m the hkvwer play a heater 1'7 coimecefii pipe 18. the purpose of 1. 5 t neramre 0f the air passihzaugh game 18 is the blower 15 I a @0152 air fillet (see 2) can- 52 :1 @3211} thermomeier 12, K prefm-ably em'pisy a defiaciior, 22, Whlfih be supparted ifz'nm the mp, 1'2

of 'he $1606; in any 201W manna? such as by straps, 2?. In mamng molcis 2.160011% 'ing in impr'fiveii pmcess 1'. 5216? i; pref embie to $11 193V 312 air to the k006i 12 air a fiempet'aiure between 14. 9 iegraes and 209 degrees F, suhstantmll'y, under pressure 01 aboui 'alhree ounces, 1m pemc-d 0% about ten minutes, and, in case of maids for 211; WhaNs am? we like, to spread the air current b means 01" 21 defiazim' just below the opening in the supply whereby it may be Tildifliifid hurixonisafiji and strike align-Kris of Uh"; mold substantialiy aqua ly and with :1 sofifizeii effect it pi'flceeds to- Ward the laws) rim of the hoofi Wham it is vented id ixhc atnwspherg. 7

By ca 'iyi'ng out the drying nmcess 1n the manner just described, I firm? that I am able in form a tough, dry, ienacius'skin on the moist maid diagrmnmaiiCally shmvn in F 19;. 4 bv meam of the sfiippied pow-5am 30, which Wm maintain the form thereof adequately for casting pmgmses, wifihout subsiaan'iiafiy aiieczing the poi-m 0f we meli, thus permitiing the mgzii productmn and:

" 4:. Tim meihod of amid regulate" current 91" heaateal 02? air, which consisfis in subjeci imm-eiiat s "(If n if failures and compar 3.053 m:

casting, thus greai harewim'e incident the "wheels swim: fracturai amid n perfecizioms in 1* r-sndarin the c 01.- scrap-mew -H2W1ng scribed my iiiustmififi i535 11253 What 1 61M desire 500 secure by Letfizers 1 st:

1. The nmthod 9i producing meta molding sm'fs m and daxisx in subjeezting ifihsa metai maid? b1 mm; 530 0 at 0 h aied iii? undm Tim m 3210:). of drying ky tin-a of air, which cmnsists in zubjaff; faae 0f :the msld to a. cm

3. meflmd 01" producing 2* .mzfli Emm mg a meta molding smfface mmpsseii 6f mixture 01 sand and dextllm winch consists 'in subjecting fshe mowing s :zfafia i0 current 01 he'atel under pressure i 01 my period of akwut ten mmuwss,

of a ia, which consists in subje 522% 033 tha male to a cur. 21?; of Zambia under pressure at a temper subgtzmtiafiy 1% degrees Fak'zre'zzhfii.

The mzeifimi sf praaiiucin ing a. mami all-aiding surfza,

sure.

Th s zxzafirpi of pmdw. ing a metai msiding surfmca omposeii :3; mixture. of sand dex brirg Whfih in subjecsing ths metal B10263??? JHFCQCS t0 distributed Currant of 19m. air 111M191" Dues sure, I

7. The mei-hod 05 nwiii haw ing a mem} maming surface campus-sci 0i? miximra of sand dextrin, which an in subjecting; the metal mokiing surfr'lcfi surreni; of hefied air under pmssum tempgmtur-e and for aperio-ri of time dent 0 form a relatively dry skin. on sufface.

8. The method of produingg' a mom. ham 112 5 amatal molding; surface compose of day; the inner pm'osity ml? such moidz memee face of the mold to a current of air heated signed my name in the presence of izl iefwo to between 140 degrees and 200 degrees Fahsubscribed Witnesses.

renheit, substantially, such air being sup- J AMES CAREY DAVIS. plied under a pressure of about three ounces Witnesses: v 5 for a period of about ten minutes. MARTHA WESTMAN,

In testimony whereof I have hereunto PAUL CARPENTER.

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