US1013190A - Case-hardening apparatus. - Google Patents

Description

A. W. MAGHLET. CASE HARDENING APPARATUS. APPLICATION FILED MAY 17, 1906.

m Mm H m LM m m tw W m .m m M e 3 M Q N .N m m m 9 8 N m 1 o H m s I 5 v A. W. MAOHLET. CASE HARDENING APPARATUS. APPLICATION FILED MAY 17, 1906.

Patented Jan. 2, 1912.

2 SHEETS-SHEET 2.

//V 1/5 /1/ TOR Iiil WITNESSES:

ATTORNEY I the flames, and then ADOLPH 'W. MACHLET, OF ELIZABETH, NEW JERSEY.

CASE-HARDENING APPARATUS. J

Specification of Letters Patent.

Application filed May 17, 1906. Serial No. 317,315.,

To all whom it may concern:

Be it known that I, ADoLPH W. MACHLET, a citizen of the United States, residing in Elizabeth, in the county of Union and State of New Jersey, have inventedcertain new and useful Improvements in Case-Hardening Apparatus, of which the following is aspecification.

This invention relates to chemically treating articleswhile heated and especially to case-hardening steel or iron articles inbulk.

In my co-pending application No. 244,244, filed February 4, 1905, (Patent No. 822,460, dated June 5, 1906,) is set forth a manner of case-hardening by inc'losing articles in a retort, and both heating and rotating the retort While a current of carburizing gas circulates therethrough.

The obj ects of the present invention are to simplify and reduce the cost of the apparatus and the operation and to adapt the. same for certain kinds of work.

According articles are placed chamber of an oven directly in the flame and heated directly by the flames are extinguished, and the oven is filled with oarburizing gas, which cements the articles by means of their ownretained heat; a gentle agitation of the articles throughout the heating and carburizing operations. This agitation is preferably effected by means of a revolving barrel mounted within the oven and containing one or more cylindrical rolling shells which hold the articles; both the barrel and the shells being open to permit free circulation of carburizing gas therethrough. The barrel is provided with a lid or closure, through which the shells may be removed; and the oven preferably has a lid in the form of a removable top to afford access to the barrel. The walls of the oven are greatly thickened for the purpose of retaining heat,thus delaying the cooling of the articles sufliciently to enable them to be substantially cemented by their retainedIheat, or bythe heat retained in the oven. The lid of the oven is provided with one or more capacious vents for the escape of products of combustion during the heating of the articles, and these vents are provided with closures, whereby they may be closed during the subsequent ('arlmrizing operation; and the oven is also provided with a constricted regulatable vent for controlling the flow of carburizing gas through to the present invention, the

being maintained 1 preferably introduced into the oven through the same pipe which feedslthe burners; and means are providedfor diluting the carburizing gas by means of an inert gas, such as ammonia. Y

1 Other objects, features and advantages will hereinafter appear.

In the accompanying drawings, Figure 1 is a vertical longitudinal section of an apparatus for case-hardening according to the present invention. Fig. 2 is a plan of a re-,

volving barrel or cage showing particularly the hinged closure of the barrel through which the shells may be inserted and removed. Fig. 3 is an elevation of one end of the apparatus. Fig. 4 is a transverse section of the apparatus.

The even comprises walls 3, 4, bottom or base wall 5, and top wall or cover 6. These walls, which are made of refractory material, are greatly thickened in proportion to the capacity of the oven, so that they retain heat, thereby to delay the cooling of the articles, and hence prolong thecementing operation until a substantial-shell is formed upon the contained articles. The walls rest upon an iron base plate 7, supported upon legs 8. iron boxing-9 confines the side and end walls. The lid 6, which is very heavy and rests upon the top edges of the side and end walls, is lifted off when desired by means of chains 10, to give access to the interior of the oven. In the 11, which are open during the operation of heating the oven, and may be closed by.

the oven. The carburizing gas is end walls 1, 2, sidelid 6 are provided capacious vents Patented Jan. 2,1912.

conical plugs 12 during the subsequent filling of the oven with carburizing gas.

Gas or other fuel is supplied to the oven through a pipe 13 controlled by a valve 14;

and air is supplied through a pipe 15 controlled by a valve 16; the air being preferably supplied under pressure. The mixed air and fuel are distributed by means of pipes 17, 18, 19 and 20, to burners 21 in the base of the oven. Preferably the burners are arranged in two series in the opposite. walls 3, 4, so as to direct the flames along the floor 5 of the oven. A thick plate 22 of either iron or refractory material may lie horizontally just above the burners, spaces being left at 23 around the edges of the screen for the passage of flames up into the body of the oven, whereby the flames are caused to heat the walls of the oven very hot, as well as articles contained therein. The screen also because of its great thickness serves as a reservoir of heat effective to prolong the carburizing operation.

Extending through the end walls 1 and 2 of the oven is a horizontalshaft 24-, which is preferably made of substantial proportions, so as to avoid collapse while heated, and the shaft is preferably hollow as illustrated, so as to reduce the weight that must be supported by the heated metal, without substantially weakening the shaft. Secured upon said shaft by means of hubs 25, are opposite heads 26, connected by bars 27 preferably four in number; the ends of the bars being upset and attached to the heads by means of bolts 28, thus forming a rigid structure. Hoops 29 are placed at intervals between the heads-and supported upon the bars 27, thus forming an open work barrel or cage. A segment 29 of each hoop 1s hinged upon a rod 30 extending along the' barrel; and these hinged form aclosure are locked in by means of slide bolts 31 passing through eyes 32 provided upon the hinges, and en: gaging alining eyes 33 provided upon the barrel heads. 1 Within the barrel are shown three cylindrical shells or canisters 34 adapted to roll upon the interior sides of the hoops 29 when the barrel is rotated; the shells always tending to find the bottom ofthe barrel, as will be understood by reference, to Fig. 4. 'The articles to be case-hardened are placed within the shells, the latter having coned ends 34, which, though open at 34" for enabling gas to circulate freely therethrough, are still sufficiently closed toretain the articles, with which each shell may be only partly filled. In order to insert'or remove the shells, the lid 6 of the oven is lifted and swung aside, and the closure of the barrel is unbolted and swung up.

The shaft 24 is revolubly supported by means placed at the exterior of the oven where they are not injured by heat. The ends of the shaft 24 projects through en'- larged holes 24 in the walls 1 and 2. The left hand endtof the shaft at Fig.1 turns upon a pair of trundles 35 carried upon brackets 36 securedto the casing 9 of the furnace. The other end of the shaft is provided with a collar 37 supported upon a pair of trundles 38, said collar having flanges 39 to engage said trundles, to prevent endwise displacement of the shaft. The gradual permanent elongation of the shaft due to repeated heating and cooling thereof, is accommodated by permitting the trundles 35 to engage directly with the shaft itself, since this end of theshaft' may freely slide endwise upon said trundles. The shaft is rosegments which closed positions tated by means of a worm wheel 40- cast upon the collar 37 and operated by a worm of fresh gas. This 41 secured upon a shaft 42, the latter having a sprocket wheel 43 connected bya chain 44 to any source of power.

.In operation the lid 6 is lifted, the barrel hoop segments 29 unbolted and raised, and the shells 34 removed, filled with articles and replaced. Then the segments 29 are closed and locked by the bolts 31. The valves 14 and 16 are then opened and the mixture is ignited at the burners 21, whereupon the lid 6 is replaced, the products of combustion escaping through the vent or vents 11. The barrel is slowly rotated, so that the articles contained in the shells are kept in constant gentle agitation, whereby they may become evenly heated. -Thehead of the barrel may be formed with the ends of the shells, so as to retain the latter. The heating proceeds until the articles reach a carburizing heat which is say above red heat and below the melting point; at-

which time the walls of the oven aswell as the screen 22 are heated to about the same temperature as the articles. Thereupon the valve 16 is closed to cut off the air and extinguish the flames at the burners, and the vents 11 are closed by the plugs 12; and gas may continue to flow in through the pipe 13 to immediately fill the oven and carburize the articles in the shells; this gas being of any suitable quality, carburizing fluid. The rotation of the barrel is continued throughout the carburizing operation, so that the articles may be ex- 'posed all over to the atmosphere of gas and ence evenly cemented.

Preferablya constricted vent pipe 46 is fitted'in the lower part of one of the walls of'the ing gas may pass slowl throu h the oven, thus insuring the drawiri g ofi of the vitiated gas, and the renewal through the pipe 13 vent maybe re lated by a valve 47. The gas escapingt rough this vent and igniting in the air shows its condition by the color of its flame. The operator is hence enabled to control the condition and ,flowof the gaseous atmosphere in the oven by regulating either valve 47 or 14 or both. Owing to the thickness of the heated walls, articles is greatly delayed, and they are enabled to become cemented to a substantial depth by means of their own retained heat, or preferably by means of the heat retained in' the oven. certain extent, the chemical action of the gas thereon ceases; and they may then be removed from the oven or retort and immediately replaced by other articles, so that the operation of heating may be repeated before the walls of the oven have lost a great amount of heat. In case the cementation does not proceed to a sufiicient depth, they may be allowed to remain in the oven,

rings 45 to' be engaged by as coal gas or any other oven, so thatthe current of carburiz- After the articles cool to aof heating the oven. and ammoma may whereupon the flames may be again ex-i tinguished and carb urizing gas supplied to.

the oven, thus causing the cementation-of the articles to proceed to a greater depth; and this operation may be repeated onthe same articles until they have the required depth of cementation; the agitation thereof being continued throughout the repeated heating and carburizing operations.

Ammonia or other inert gas ma be admitted through a pipe 48 which wins the pipe 17 and is provided with a valve 49, the latter being closed during the operation be controlled by said valve 49; or other'means may be provided for securing asupply of diluted gasto the oven. It will be seen. burning mixture, but also the carburizing gas, with or without its dilutant are admitted through the burners; but the carburizing gas either dilutedv or not may be otherwise introduced into the oven.

The invention is of great value in casehardening ordinary wire nails, as well as other small articles. A-case hardened nail possesses great advantage over the ordinary nail in that it has sufiicient strength in proportion to its diameter. In other words the ordinary nail is too weak to stand the pounding necessary. to make a hole in the wood of the diameter of the nail; but by case-hardening the nail this difficulty is overcome. Thenails may be readily casehardened in bulk by the herein described means.

Variations may be resorted to within the scope of the invention, and portions of my improvements may be used without others. 1Having thus described 'my invention, I c aim:

1. The combination of a closed heatinga barrel in said receptacle, and exterior of the receptacle and receptacle, means at'the connected to said barrel for revolving the same; said barrel comprising a pair of heads, a series of hoops between said heads,

, and bars connecting .said heads and supporting said hoops, and canisters confined in said barrel to be tumbled thereby for the purpose specified.

-. 2. The combination of a closed heating receptacle, 'a barrel contained in said receptacle, and means at the exterior of the receptacle and connected to said barrel for revolving the same said barrel comprising a pair of heads, a series of hoops between The mixture of gas that not only the said heads, and bars connecting said heads and supporting said hoops; each hoop having a section which is hinged to give access to the interior of the barrel.

3.-The combination of a closed heating receptacle,

heating receptacle,

a barrel contained in said receptacle, means at the exterior of the receptacle and connected to said barrel for revolving the same; said barrel "comprising a pair of heads, 'a series of hoops .between said heads, and bars connecting said heads and supporting said hoops; each hoop having, a section which is hinged to give access to the interior of the, barrel, and releasable means for locking the hoops in closed relation. A

4. The combination with a closed heating receptacle, of a barrel contained in said receptacle, a shaft extending through the wall of said receptacle, and having supporting means exterior to said receptacle, and means for rotating the shaft; said' barrel comprising a pair of heads secured to the shaft, hoops between said heads, and bars connecting said. heads and supporting said hoopsya segment of each hoop extending between adjacent bars being hinged, the segment having eyes, and locln'ng bolts passing through the eyes and releasably engagilngdeyes which are provided upon sai ea s.

5. The combination ,of a closed metalheating receptacle, a barrel mounted therein for rotation, and a shell to contain the articles to be heated, said shell lying within said barrel and constructed to roll upon the in terior of the barrel when the latter is turned.

. 6. The combination of a closed metala barrel mounted therea shell to contain the in for rotation, and;

- articles to be heated, said shell lying within said barrel and constructed to roll upon the interior of the barrel when the latter is turned, both said barrel and said shell being open to permit free circulation of gas therethrough. 7. The combination of a closed metalheating rece tacle,'means for supplying gas thereto, a arrel within said receptacle,

means at the exterior of said receptacle for supporting and turning said barrel, and a plurality of rolling shells contained in said barrel, both said barrel and said shells having openings for the circulation of gas therethrough. 3

8. The combination of a closed metalheating receptacle, means for supplying gas thereto, a barrel within said receptacle, means at the exterior of said receptacle for supporting and turning said barre1,'and a plurality of rolling shells contained in said barrel, both said barrel and said shells having openings for the circulation of gas there- .through; said barrel having an opening through which said shells may be removed, and a closure for said opening. v

9. The combination of a closed metal-heating receptacle, a shaft extending through opposite wallsthereof, means at the exterior of said receptacle for supporting and turning a pair of ing said shaft, shaft within said receptacle and comprisheads, hoops intervening between. said heads and means supporting said hoops, and a cylindrical shell within said barrel and constructed to roll upon said hoops when the barrel is rotated.

10. The combination of a closed metalheating receptacle, a shaft extending through when the barrel is rotated, each of said hoops having a hinged section to permit removal of said shell, and means being provided for locking said sections said shell having openlngs at its ends for the free circulation of.

gas therethrough.

11. The combination of a closed heating receptacle, a barrel mounted therein and having openings, means for supplying gas to said receptacle, and a cylindrical shell contained in said barrel and constructed to roll within the same, said shell havingopenings at its ends for the free circulation of gas therethrough.

12. The combination of a closed-heating receptacle, a barrel mounted therein and having openings, means for supplying gas to said receptacle, and a cylindrical shell contained iii said barrel and constructed to roll within the same, said shell having open coned ends,

13. The combination with a heating chamber, of a cylindrical shell within said heating chamber and said shell having open coned ends, means Within the heating chamber for rolling said shell, and means for supplying gas to the heating chamber.

14. The combination with a closed-metaL heating chamber provided with a restricted vent, 'and' means for conducting carburizing,

gas thereto, of means contained within the chamber for effecting agitation of the metal articles contained therein, and driving mechanism exterior to the chamber and connected to said agitating means.

15. Theicombination with a closed metalheating chamber provided with a restricted vent, and means for conducting of an open device within the chamber for containing the articles to be heated, and power-driven means extending from the exterior of the chamber and through the wall thereof to said containing device, for effecting movement of the latter to agitate its contents.

- 16'. The combination with a closed metalheating chamber provided with a restricted vent, and means for conducting gas thereto,

a barrel mounted upon said said oven,

hoops intervening between,

gas thereto,

of an open shell within the chamber, and

power-driven 'mechanis'm including a part extending through the wall of the chamber whose walls are formed of refractory material, of burners for mixed air and fuel in means for supplying the oven,

after the extinction of flames at the burners,

with a gas capable of chemically acting upon the articles contained in the oven while they remain heated, and means for agitating the articles in the oven; the walls of the oven having great thickness for retaining heat so as to maintain theheat of the articles during, the action of the gas thereon.

18. The combination of a closed oven having thick walls. of refractory material, a series of burners in said oven, means for supplying mixed air and fuel to said burners, means for supplying to the oven, after I extinction of flames at the burners, carburizing as, and means for gently agitating the artlcles within the oven; said oven provided with a capacious vent for the products of combustion, and with a closure for said vent.

19. The combination of a closed oven having walls of refractory-material, said walls being thickened for the purpose of retaining heat, a series ofburners in said oven, means for supplying a burning mixture to said burners, and means for passing a slow current of carburizing gas through the oven after extinction of the flames at the burners, and power-driven mechanism partly within and partly without the oven, for agitating the articles therein.

20. The combination of a closed heating chamber in the form of an oven having thickened walls of refractory material, ase' ries of burners in said oven for burning mixed air. and fuel, means for supplying iron-earburizing gas to said oven after the extinction of the flames at said burners, a device within said oven for holding the articles to be carburized, and mechanism for moving said holding device, to agitate the articles therein; said holding device being open so as to permit circulation oficarburizing gastherein.

21. The combination of a heating chamber in the'form of an oven provided with thickened heat-retaining walls, means for creating flames in said oven and venting the products of combustion therefrom, means foresupplying iron-carburizing gas to said oven after the extinction of the flames therein, an open shell mounted within the'retort,

for containing the articles to be case-hardened, and means including a part extending through the wall of the oven, for effecting slow rotation of said shell.

i and an open rolling 22. The combination in the form of an oven having alid, means for creating flames insaid retort and then supplying carburizing gas extinction of the flames, a barrel mounted in the oven and having openings for the circulation of gas therethrough, and means outside of the oven for both supporting and rotating the barrel.

23. The combination of a heating chamber in the form of an oven, means for creating flames in said oven and for causing the ings for the circulation of gas therethrough, after extinction of the flames, a barrel movably mounted in the oven and having openings for the circulation of gas therethrough, shell contained in said barrel for holding the articles to be heated 3 said oven provided with a lid.

-a series of burners oven, and means for supplying 24:. The combination of an oven having a lid, means for creating flames in said oven and for causing the circulation of carburizing gas therethrough after extinction of the flames, a barrel mounted in the oven and having openings for the circulation of gas therethrough, an open rolling shell contained in said barrel for holding the articles to be heated, and means outside of the oven for supporting and rotating said barrel; the latter having an opening for the removal of said shell, and a closure for said opening; said oven provided with a capacious vent for the roducts of combustion; and with a closure or said vent.

25. The combination of an oven having a lid in the form of a removable top, of said oven being thickened to retain heat, for mixed airvand fuel opening into said oven, a revoluble open receiver mounted in said oven for holding the articles to be case-hardened or treated, a thick screen between said burners and said receiver, flame passages being left between the edges of the screen and the walls of the gas to said oven after extinction of flames at said burners; the oven provided with a capacious' vent for the products of combustion and with a closure for said vent, andf also with a regulatable constricted vent for regulating the passage of gas through the oven.

26. The combination with an oven having means for retaining heat, of means for cre-.

ating flames in said oven and causing them to play upon said heat-retaining means,

of a heating chamber thereto after the the walls means for causing articles in the oven to be heated uniformly throughout, means for extinguishing the, flames in the oven, and means operable after their extinction, for

' subjecting the articles uniformly to the action of gas thereon. v d

27. An apparatus for carburizing iron or steel articles, comprising a heating chamber of refractory material having three separate supply pipes 13, 15 and 48 for air, fuel gas and car urizing gas respectively, and

means for closing the air and fuel gas pipes and opening the carburizing gas pipe to the chamber, and agitating the articles.

28. A furnace in which .is' mounted a barrel revoluble upon an axle projecting through the walls of the furnace and supported upon trundles outside of the furnace, said furnace having a removable cover pro vided with vent-holes having closures, and means for introducing either gas alone or gas mixed with air; said furnace provided with a re latable constricted gas-vent.

29. -A urnace in which is mounted a bar'- rel' revoluble upon anaxle projecting through the walls of the furnace and supported upon trundles outside of the furnace, said furnace having a removable cover provided with vent-holes havingclosures,and means for introducing either gas alone or gas mixed with air; said furnace provided with a regulatable constricted gas-vent, and having in its bottom a are burners for the gas, said burnerswithin the flame chamber of the furnace.

heat-bed below which 30. The combination with a heating chamber, of a barrel mounted therein for revolution and consisting of heads, tie-rods, hoops, a hollow shaft upon-which the heads are mounted, and a canister within the barrel to contain the articles to be case-hardened.

31. The combination of a heating chamber having meansfor supplying thereto either fuel gas mixed with air or carburizing gas after the flames are extinguished, av device revolubly mounted in said heating chamber,

the latter having a removable top, and a clo'sable vent in said top for the products of combustion, and a regulatable constricted vent in the sidewall of the chamber for the carburizing gas.

slow escape of MACHLET.

ADOLPH W. Witnesses:

SAMUEL R. OGDEN, -PHILIP G. OSTERMAN.

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